application_number
string | publication_number
string | title
string | decision
string | date_produced
string | date_published
string | main_cpc_label
string | cpc_labels
string | main_ipcr_label
string | ipcr_labels
string | patent_number
string | filing_date
string | patent_issue_date
string | abandon_date
string | uspc_class
string | uspc_subclass
string | examiner_id
string | examiner_name_last
string | examiner_name_first
string | examiner_name_middle
string | inventor_list
string | abstract
string | claims
string | background
string | summary
string | full_description
string | ipcr_label_section
string | ipcr_label_class
string | ipcr_label_subclass
string | ipcr_label_group
string | ipcr_label_subgroup
string |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
11749149
|
US20070211113A1-20070913
|
WIDE FORMAT PRINT ASSEMBLY HAVING CMOS DRIVE CIRCUITRY
|
ACCEPTED
|
20070829
|
20070913
|
[]
|
B41J204
|
["B41J204"]
|
7591534
|
20070515
|
20090922
|
347
|
042000
|
76004.0
|
NGUYEN
|
LAMSON
|
[{"inventor_name_last": "Silverbrook", "inventor_name_first": "Kia", "inventor_city": "Balmain", "inventor_state": "", "inventor_country": "AU"}]
|
A print assembly is provided having an elongate carrier that is mountable on a support structure of a printer, printhead integrated circuits mounted on the carrier, and CMOS drive circuitry positioned on the carrier and operatively connected to the printhead integrated circuits to drive operation thereof. The printhead integrated circuits are provided in a number and configuration such that the printhead integrated circuits define an elongate printing zone of at least 914 mm. Each printhead integrated circuit incorporates nozzle arrangements each having a nozzle, an ink chamber, an ink inlet, an actuator, and a drive circuit to achieve the ejection of ink from the nozzle arrangement.
|
1. A print assembly comprising: an elongate carrier mountable on a support structure of a printer; a plurality of printhead integrated circuits mounted on the carrier, the printhead integrated circuits being provided in a number and configuration such that the printhead integrated circuits define an elongate printing zone of at least 914 mm, each printhead integrated circuit incorporating a plurality of nozzle arrangements, each nozzle arrangement comprising a nozzle, an ink chamber, an ink inlet, an actuator, and a drive circuit to achieve the ejection of ink from the nozzle arrangement; and CMOS drive circuitry positioned on the carrier and operatively connected to the printhead integrated circuits to drive operation thereof. 2. A print assembly as claimed in claim 1, wherein the nozzle arrangements are positioned on CMOS drive circuitry layers defined on wafer substrates, the CMOS drive circuitry being connected to the CMOS layers of the printhead integrated circuits. 3. A print assembly as claimed in claim 1, wherein the nozzle arrangements and CMOS drive circuitry are configured so that the printhead integrated circuits are driven by the CMOS drive circuitry to print more than one billion drops of ink per second. 4. A print assembly as claimed in claim 3, wherein the printhead integrated circuits are driven by the CMOS drive circuitry to print at least 1.8 billion drops of ink per second. 5. A print assembly as claimed in claim 3, wherein the printhead integrated circuits are driven by the CMOS drive circuitry to print up to 21.6 billion drops of ink per second. 6. A print assembly as claimed in claim 1, wherein the CMOS drive circuitry incorporates a plurality of print engine integrated circuits positioned on the carrier, each print engine integrated circuit being connected to an associated number of the printhead integrated circuits. 7. A print assembly as claimed in claim 6, wherein each print engine integrated circuit is connected to up to sixteen printhead integrated circuits. 8. A print assembly as claimed in claim 6, wherein each print engine integrated circuit drives operation of at least 100,000 nozzle arrangements. 9. A print assembly as claimed in claim 6, wherein each print engine integrated circuit incorporates processing circuitry for processing print data to be printed by the printhead integrated circuits. 10. A print assembly as claimed in claim 1, wherein between 40 and 100 printhead integrated circuits are mounted on the carrier. 11. A print assembly as claimed in claim 1, wherein the printhead integrated circuits are each positioned at a common angle of greater than zero degrees and less than ninety degrees with respect to a straight line extending at right angles to a feed direction of print media, with consecutive ends of the printhead integrated circuits overlapping to ensure continuous printing in the printing zone. 12. A print assembly as claimed in claim 1, wherein the a plurality of modules are detachably mounted on the carrier, one printhead integrated circuit being incorporated in each module. 13. A print assembly as claimed in claim 1, wherein an ink reservoir assembly is mounted on the carrier in fluid communication with the printhead integrated circuits, the ink reservoir assembly being configured to supply the printhead integrated circuits with at least three inks of different colors. 14. A pagewidth inkjet printer comprising: a support structure; a print assembly as claimed in claim 1 supported by the support structure; and a feed mechanism supported by the support structure for feeding print media though the printing zone.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>High volume, high resolution printing is an objective that has been sought by the manufacturers of wide format printers for some time. Wide format printers have been available to the public for many years. Examples of popular wide format printers are the Hewlett Packard (HP) 1000/5000, the HP 3000/3500, the Epson 7000/10000 and many others. These printers all have a traversing printhead that traverses a print medium while depositing ink on the medium. Applicant believes that these printers suffer from inherent disadvantages, particularly when attempts are made to utilize the design of such printers in order to achieve faster printing speeds at high resolutions. Central to the problem of achieving high printing speeds is the ability to achieve a printhead that is capable of generating the necessary number of ink dots at a suitable rate. Further, in order to achieve accurate printing, it is desirable that a row or band of the image be created in as little print cycles as possible, and preferably in a single print cycle. It follows that it is undesirable for a traversing printhead to be used in an attempt to achieve high print speeds and that a single printhead incorporating a suitable number of inkjet nozzles is required. Thermal printheads also referred to as bubble jet printheads and piezoelectric printheads have been available for some time. These suffer from excessive heat build up and energy consumption and have therefore been found by the applicant to not be suitable for use in a pagewidth configuration. A number of disadvantages associated with such printheads are set out in U.S. Pat. No. 6,443,555. The applicant has developed a printhead chip that is capable of producing images having a resolution as high as 1600 dpi. These chips are manufactured using integrated circuit fabrication techniques. Details of the chips are provided in the above referenced applications and patents. Applicant believes that these printhead chips are extremely suitable for use in wide format printers. The reason for this is that such chips operate at extremely high speeds due to the large number of nozzle arrangements required in a single chip and due to the fact that such chips can be driven at an extremely high cyclical rate. The Applicant has been faced with a number of difficulties in order to achieve the effective use of such printhead chips in wide format printers. One particular difficulty identified by the Applicant is the effective control of a number of such printhead chips to achieve accurate printing. This control must incorporate the use of effective image processing tools that are capable of processing stored images at a rate that corresponds with the physical rate of printing achievable by a number of the above printhead chips. Another difficulty that faces the manufacturers of wide format printers are the problems associated with heat build up. This can often result in the necessity for expensive heat extraction devices that add to the complexity of the printer.
|
<SOH> SUMMARY OF THE INVENTION <EOH>According to a first aspect of the invention, there is provided a printing mechanism that comprises an elongate support structure; a pair of busbars that are mounted on the support structure; a plurality of printed circuit boards that are mounted on the support structure to be electrically connected to the busbars, each printed circuit board including print engine control circuitry that is configured to control operation of a number of printhead chips; a plurality of ink distribution structures that are mounted on the support structure and connectable to a supply of ink; and a plurality of printhead modules that are mounted on respective ink distribution structures, each printhead module having a carrier and a printhead chip positioned on the carrier, each printhead chip having a plurality of nozzle arrangements that are positioned on a wafer substrate, each nozzle arrangement incorporating a micro-electromechanical actuator for ejecting ink from a nozzle chamber, and being mounted on a respective ink distribution assembly, a number of the printhead chips being connected to the print engine control circuitry such that each nozzle arrangement can receive data signals from the print engine control circuitry. The support structure may include an elongate chassis that is interposed between a pair of end supports, the chassis being shaped to support the printed circuit boards on one side of the chassis and the ink distribution structures on another side of the chassis, with the busbars interposed between the printed circuit boards and said one side of the chassis. Each printhead module may include a flexible printed circuit board that interconnects the printhead chip to the control circuitry. The print engine control circuitry of each printed circuit board may be defined by an integrated circuit. The support structure may include a channel member that is mounted on the chassis and the ink distribution structures may be positioned in a channel defined by the channel member. Each ink distribution structure may define a plurality of ink reservoirs that extend through the ink distribution structure such that ink reservoirs extend a length of the channel member when the ink distribution structures are positioned in the channel. The printing mechanism may include a connecting assembly that is mounted on an endmost ink distribution structure to permit a plurality of ink conduits to be connected to the endmost ink distribution structure with each conduit being in fluid communication with a respective ink reservoir. According to a second aspect of the invention, there is provided a print assembly for a wide format pagewidth inkjet printer, the print assembly comprising an elongate carrier that is mountable on a support structure of the printer and is positioned an operative distance from a platen of the printer; a number of printhead chips that are mounted on the carrier, the printhead chips being provided in a number and configuration such that the printhead chips define a printing zone between the carrier and the platen, the printing zone having a length of at least 36 inches (914 mm), each printhead chip being of the type that incorporates a plurality of nozzle arrangements, each nozzle arrangement being in the form of a micro electromechanical system to achieve the ejection of ink from the nozzle arrangement; and control circuitry that is positioned on the carrier and is operatively connected to the printhead chips to control operation of the printhead chips. According to a third aspect of the invention, there is provided a wide format pagewidth inkjet printer that comprises a support structure; a platen positioned in the support structure; a print assembly positioned operatively with respect to the platen, the print assembly comprising an elongate carrier that is mounted on the support structure of the printer and is positioned an operative distance from the platen; a number of printhead chips mounted on the carrier, the printhead chips being provided in a number and configuration such that the printhead chips define a printing zone between the carrier and the platen, the printing zone having a length of at least 36 inches (914 mm), each printhead chip being of the type that incorporates a plurality of nozzle arrangements, each nozzle arrangement being in the form of a micro electromechanical system to achieve the ejection of ink from the nozzle arrangement; and control circuitry that is positioned on the carrier and is operatively connected to the printhead chips to control operation of the printhead chips; and a feed mechanism that is positioned on the support structure for feeding a print medium though the printing zone. The invention is now described, by way of example, with reference to the accompanying drawings. The following description is not intended to limit the broad scope of the above summary.
|
CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation of U.S. application Ser. No. 11/478,588 filed on Jul. 3, 2006, which is a continuation of U.S. application Ser. No. 11/231,875 filed on Sep. 22, 2005, now issued U.S. Pat. No. 7,172,265, which is a continuation of U.S. application Ser. No. 11/082,932 filed on 18 Mar. 2005, now issued as U.S. Pat. No. 7,008,041, which is a continuation of U.S. application Ser. No. 10/743,759 filed on Dec. 24, 2003, now issued as U.S. Pat. No. 6,916,082 which is a continuation-in-part of U.S. application Ser. No. 10/120,351 filed on Apr. 12, 2002, now issued as U.S. Pat. No. 6,672,706, which is a continuation-in-part of U.S. application Ser. No. 09/112,767 filed on Jul. 10, 1998, now U.S. Pat. No. 6,416,167, the entire contents of which are herein incorporated by reference. The following United States applications and patents are hereby incorporated by reference: 6,227,652 6,213,588 6,213,589 6,231,163 6,247,795 6,394,581 6,244,691 6,257,704 6,416,168 6,220,694 6,257,705 6,247,794 6,234,610 6,247,793 6,264,306 6,241,342 6,247,792 6,264,307 6,254,220 6,234,611 6,302,528 6,283,582 6,239,821 6,338,547 6,247,796 6,390,603 6,362,843 6,293,653 6,312,107 6,227,653 6,234,609 6,238,040 6,188,415 6,227,654 6,209,989 6,247,791 6,336,710 6,217,153 6,416,167 6,243,113 6,283,581 6,247,790 6,260,953 6,267,469 6,273,544 6,309,048 6,420,196 6,443,558 6,439,689 6,378,989 6,406,129 6,505,916 6,457,809 6,457,812 6,428,133 6,362,868, 6,443,555 6,634,735 6,557,977 6,623,101 FIELD OF THE INVENTION This invention relates to a wide format pagewidth inkjet printer. More particularly, this invention relates to a printing mechanism for a wide format pagewidth inkjet printer and to a wide format pagewidth inkjet printer. BACKGROUND OF THE INVENTION High volume, high resolution printing is an objective that has been sought by the manufacturers of wide format printers for some time. Wide format printers have been available to the public for many years. Examples of popular wide format printers are the Hewlett Packard (HP) 1000/5000, the HP 3000/3500, the Epson 7000/10000 and many others. These printers all have a traversing printhead that traverses a print medium while depositing ink on the medium. Applicant believes that these printers suffer from inherent disadvantages, particularly when attempts are made to utilize the design of such printers in order to achieve faster printing speeds at high resolutions. Central to the problem of achieving high printing speeds is the ability to achieve a printhead that is capable of generating the necessary number of ink dots at a suitable rate. Further, in order to achieve accurate printing, it is desirable that a row or band of the image be created in as little print cycles as possible, and preferably in a single print cycle. It follows that it is undesirable for a traversing printhead to be used in an attempt to achieve high print speeds and that a single printhead incorporating a suitable number of inkjet nozzles is required. Thermal printheads also referred to as bubble jet printheads and piezoelectric printheads have been available for some time. These suffer from excessive heat build up and energy consumption and have therefore been found by the applicant to not be suitable for use in a pagewidth configuration. A number of disadvantages associated with such printheads are set out in U.S. Pat. No. 6,443,555. The applicant has developed a printhead chip that is capable of producing images having a resolution as high as 1600 dpi. These chips are manufactured using integrated circuit fabrication techniques. Details of the chips are provided in the above referenced applications and patents. Applicant believes that these printhead chips are extremely suitable for use in wide format printers. The reason for this is that such chips operate at extremely high speeds due to the large number of nozzle arrangements required in a single chip and due to the fact that such chips can be driven at an extremely high cyclical rate. The Applicant has been faced with a number of difficulties in order to achieve the effective use of such printhead chips in wide format printers. One particular difficulty identified by the Applicant is the effective control of a number of such printhead chips to achieve accurate printing. This control must incorporate the use of effective image processing tools that are capable of processing stored images at a rate that corresponds with the physical rate of printing achievable by a number of the above printhead chips. Another difficulty that faces the manufacturers of wide format printers are the problems associated with heat build up. This can often result in the necessity for expensive heat extraction devices that add to the complexity of the printer. SUMMARY OF THE INVENTION According to a first aspect of the invention, there is provided a printing mechanism that comprises an elongate support structure; a pair of busbars that are mounted on the support structure; a plurality of printed circuit boards that are mounted on the support structure to be electrically connected to the busbars, each printed circuit board including print engine control circuitry that is configured to control operation of a number of printhead chips; a plurality of ink distribution structures that are mounted on the support structure and connectable to a supply of ink; and a plurality of printhead modules that are mounted on respective ink distribution structures, each printhead module having a carrier and a printhead chip positioned on the carrier, each printhead chip having a plurality of nozzle arrangements that are positioned on a wafer substrate, each nozzle arrangement incorporating a micro-electromechanical actuator for ejecting ink from a nozzle chamber, and being mounted on a respective ink distribution assembly, a number of the printhead chips being connected to the print engine control circuitry such that each nozzle arrangement can receive data signals from the print engine control circuitry. The support structure may include an elongate chassis that is interposed between a pair of end supports, the chassis being shaped to support the printed circuit boards on one side of the chassis and the ink distribution structures on another side of the chassis, with the busbars interposed between the printed circuit boards and said one side of the chassis. Each printhead module may include a flexible printed circuit board that interconnects the printhead chip to the control circuitry. The print engine control circuitry of each printed circuit board may be defined by an integrated circuit. The support structure may include a channel member that is mounted on the chassis and the ink distribution structures may be positioned in a channel defined by the channel member. Each ink distribution structure may define a plurality of ink reservoirs that extend through the ink distribution structure such that ink reservoirs extend a length of the channel member when the ink distribution structures are positioned in the channel. The printing mechanism may include a connecting assembly that is mounted on an endmost ink distribution structure to permit a plurality of ink conduits to be connected to the endmost ink distribution structure with each conduit being in fluid communication with a respective ink reservoir. According to a second aspect of the invention, there is provided a print assembly for a wide format pagewidth inkjet printer, the print assembly comprising an elongate carrier that is mountable on a support structure of the printer and is positioned an operative distance from a platen of the printer; a number of printhead chips that are mounted on the carrier, the printhead chips being provided in a number and configuration such that the printhead chips define a printing zone between the carrier and the platen, the printing zone having a length of at least 36 inches (914 mm), each printhead chip being of the type that incorporates a plurality of nozzle arrangements, each nozzle arrangement being in the form of a micro electromechanical system to achieve the ejection of ink from the nozzle arrangement; and control circuitry that is positioned on the carrier and is operatively connected to the printhead chips to control operation of the printhead chips. According to a third aspect of the invention, there is provided a wide format pagewidth inkjet printer that comprises a support structure; a platen positioned in the support structure; a print assembly positioned operatively with respect to the platen, the print assembly comprising an elongate carrier that is mounted on the support structure of the printer and is positioned an operative distance from the platen; a number of printhead chips mounted on the carrier, the printhead chips being provided in a number and configuration such that the printhead chips define a printing zone between the carrier and the platen, the printing zone having a length of at least 36 inches (914 mm), each printhead chip being of the type that incorporates a plurality of nozzle arrangements, each nozzle arrangement being in the form of a micro electromechanical system to achieve the ejection of ink from the nozzle arrangement; and control circuitry that is positioned on the carrier and is operatively connected to the printhead chips to control operation of the printhead chips; and a feed mechanism that is positioned on the support structure for feeding a print medium though the printing zone. The invention is now described, by way of example, with reference to the accompanying drawings. The following description is not intended to limit the broad scope of the above summary. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, FIG. 1 shows a schematic, three-dimensional view of part of a printing mechanism of a print assembly, in accordance with the invention, of a printer, also in accordance with the invention; FIG. 2 shows a front view of the printing mechanism of FIG. 1; FIG. 3 shows a rear view of the printing mechanism of FIG. 1; FIG. 4 shows a three dimensional, external view of the printer; FIG. 5 shows a schematic, three-dimensional view of operative parts of the printer; FIG. 6 shows a schematic, exploded view of the printer; FIG. 7 shows a schematic, side sectioned view of a portion of the printer incorporating the print assembly; FIG. 8 shows an exploded view of an operative portion of the printing mechanism; FIG. 9 shows a cross sectional view of an operative portion of the printing mechanism; FIG. 10 shows a high-level block diagram of an image processing apparatus of the print assembly; FIG. 11 shows an expanded block diagram of a page expansion unit of the image processing apparatus; FIG. 12 shows a block diagram of the image processing apparatus incorporating the page expansion unit; FIG. 13 shows a schematic, three-dimensional view of part of a printhead chip of the print assembly of the printer, showing one nozzle arrangement of the printhead chip; and FIG. 14 shows a schematic, three-dimensional view of a printhead module that incorporates a printhead chip. DETAILED DESCRIPTION OF THE INVENTION In FIG. 4, reference numeral 10 generally indicates a printer, in accordance with the invention. The printer 10 has a support structure 12 that supports a print assembly 14, also in accordance with the invention, above a substrate. The support structure 12 includes a pair of spaced feet 16 and a leg 18 extending from each foot 16. The print assembly 14 is mounted on the legs 18 to span the legs 18. A media tray 20 is positioned between the legs 18. The media tray 20 is configured to store suitable print media, such as paper 22. The paper 22 is fed from a media feed mechanism in the form of a media roll 166 through the print assembly 14 and on to a take up spool 24. An electronics enclosure 26 is also positioned between the legs 18 to enclose various electronic components that are described below. The print assembly 14 includes a lid 28, with a handle 30, and a front cover 32. The lid 28 and front cover 32 are positioned between a pair of end moldings 34. The print assembly 14 also includes a color TFT LCD 36 with touch screen navigation. A stop button 38 is also provided to enable a user to stop operation of the print assembly 14. The print assembly 14 and its various components are shown in further detail in the remaining Figures. In FIGS. 1 to 3, reference numeral 40 generally indicates a printing mechanism of the print assembly 14. As can be seen in the drawings, the printing mechanism 40 is segmented. In particular, the printing mechanism 40 includes an image processing apparatus, in accordance with the invention, that includes nine printed circuit boards (PCB's) 42 connected to each other with corresponding connector blocks 44. The printing mechanism 40 further includes a printhead 41 having seventy-two printhead modules 46. Each PCB 42 is configured to control eight printhead modules 46. It follows that nine PCB's 42 are provided. The printhead modules 46 are described in further detail below. Each PCB 42 includes a print engine controller (PEC) 48. The PEC's 48 are also described in further detail below. Each PCB 42 also includes a memory storage device in the form of memory chips and more particularly in the form of 64 Mbit external DRAM chips 50. The DRAM chips 50 cooperate with the PEC 48 in a manner that is described below. Further, each PCB 42 includes a quality authentication (QA) chip 52. Details of a suitable QA chip are set out in the above referenced U.S. Pat. No. 6,362,868 and are therefore not set out in this description. The QA chip 52 serves to inhibit unauthorized refilling of ink in the manner described in U.S. Pat. No. 6,362,868, in addition to other functions such as ensuring the quality of print media used with the printer 10. An endmost PCB 42 includes a serial connector 54 that permits serial data cables 56 to be connected to the PCB's 42. Each PCB 42 is connected to its associated printhead modules 46 with a flexible PCB 58. The printing mechanism 40 includes a metal chassis 60 that extends between a pair of side moldings 61 that are positioned in the end moldings 34. The PCB's 42 are mounted on the chassis 60. The chassis 60 has a generally U-shaped cross section. A channel 62 of an Invar alloy is positioned on the chassis 60. A chassis molding 64 of a plastics material is positioned on an outside of the chassis 60 and the channel 62. Each PCB 42 is mounted on the chassis molding 64. The chassis molding 64 defines a pair of recesses 66 on an outer side of the chassis molding 64. The recesses 66 extend a length of the chassis molding 64. A busbar 68 is positioned in each recess 66. The busbars 68 are configured to supply electrical power to the PCB's 42. An ink reservoir assembly 70 is positioned in the Invar channel 62. The ink reservoir assembly 70 includes an ink distribution arrangement 72. Each printhead module 46 is positioned on a respective ink distribution arrangement 72. In particular, each printhead module 46 is removably mounted on its ink distribution arrangement 72 to facilitate removal and replacement when necessary. The ink reservoir assembly 70 includes a plurality of ink reservoir moldings 76. Each ink reservoir molding 76 corresponds with an associated printhead module 46. The ink reservoir moldings 76 are positioned end-to-end along and within the Invar channel 62. Each ink reservoir molding 76 defines a plurality of elongate ink channels 74, each accommodating a differently colored ink. Thus, effective elongate ink channels extend a length of the Invar channel 62. An end cap molding 78 is positioned on an endmost ink reservoir molding 76. The end cap molding 78 has a plurality of connectors 80 defined thereon and in alignment with respective ink channels 74 when the end cap molding 78 is positioned on said endmost ink reservoir molding 76. The connectors 80 are connectable to an ink hose connector 82. The ink hose connector 82 is, in turn, connected to each of a plurality of ink hoses 84. It follows that each hose 84 is in fluid communication with a respective ink channel 74. Each hose 84 supplies the ink reservoir assembly 70 with ink of a particular color. For example, the hoses 84 can carry Cyan (C), Magenta (M), Yellow (Y) and Black (K) inks, respectively. In this case, four hoses 84 are provided. Also, each reservoir molding 76 defines four ink channels 74. Alternatively, the hoses 84 can carry Cyan (C), Magenta (M), Yellow (Y), Red (R), Green (G) and Blue (B) inks, respectively. In this case, six hoses 84 are provided. Also, each reservoir molding 76 then defines six ink channels 74. Instead of six differently colored inks, the six hoses 84 can carry CMYK and Infrared (IR) inks and a fixative (F) for high speed printing so that the inks can dry rapidly. Each hose 84 is connected to a respective ink container 86 (FIG. 5), so that each hose 84 is connected between an ink container 86 and a particular ink channel 74. The hoses 84 are connected to their respective containers 86 with T-piece connectors 94 shown in FIG. 1. The print assembly 14 includes a plurality of capping devices 88 that correspond with respective printhead modules 46. Each capping device 88 is displaceable between an operative position in which it serves to cap its respective printhead module 46, to inhibit drying of ink, and an inoperative position in which ink can be ejected from the printhead module 46. A camshaft 90 is positioned in the chassis 60. A translating member 92 interconnects the camshaft 90 and the capping devices 88, so that rotational movement of the camshaft 90 results in reciprocal movement of the capping devices 88 between their operative and inoperative positions. The camshaft 90 is driven with a suitable motor, indicated generally at 96 in FIG. 5. Further detail of the print assembly 14 is shown in FIG. 7. As can be seen in this drawing, the front cover 32, the lid 28 and a rear cover 98 together define a housing 100 for the print assembly 14. A plurality of ink cartridges 102 is positioned beneath the lid 28. Each ink cartridge 102 stores one of the inks mentioned above. Each ink cartridge 102 is positioned between a pair of clips 104 so that it can be replaced when necessary. Each ink cartridge 102 and a respective ink reservoir 86 are in fluid communication with each other, when the ink cartridge 102 is received between the clips 104. A pair of platens, in the form of an upper platen 106 and a lower platen 108 is positioned within the housing 100. A pair of spaced primary rollers in the form of an upper primary roller 110 and a lower primary roller 112 is provided to displace the paper 22 through the print assembly 14. The upper roller 110 is positioned at an upper end of the platens 106, 108, while the lower roller 112 is positioned between the platens 106, 108. The rollers 110, 112 are configured to drive a sheet of the paper 22 over, consecutively, an inner surface of the lower platen 108 and an outer surface of the upper platen 106. Thus, the paper 22 passes over the upper roller 110, while the lower roller 112 is positioned between upwardly and downwardly moving portions of the paper 22. A brush 114 is pivotally mounted at 116 to the housing 100. The brush 114 has an arcuate transverse profile that corresponds with the upper primary roller 110. The brush 114 is positioned in the housing 100 so that the paper 22 can pass between the brush 114 and the housing 100. A pinch roller 118 is positioned downstream of the brush 114 to bear against the upper primary roller 110. Thus, when the paper 22 is displaced from between the brush 114 and the upper primary roller 110, the pinch roller 118 retains the paper 22 against lateral movement. The upper platen 106 defines an upper printing zone 120 and a lower cutting zone 122. A gap 124 is defined between the upper and lower printing zones 120, 122. A plurality of spiked wheels 126 is partially received through the gap 124 to engage the paper 22 and the lower primary roller 112. A crossbar 128 is operatively positioned with respect to the spiked wheels 126 to retain the spiked wheels 126 in position. The spiked wheels 126 and the pinch roller 118 are configured so that a suitable tension is set up in the paper 22 when the paper 22 passes over the printing zone 120 of the upper platen 106. The chassis 60 and channel 62 are positioned above the printing zone 120 of the upper platen 106. The chassis 60 and the channel 62 are connected to a displacement mechanism 129 so that the chassis 60 and channel 62 can be displaced from the printing zone 120 when necessary. In particular, the chassis 60 and channel 62 are displaceable between an operative position in which the printhead modules 46 are a distance from the printing zone 120 that is suitable for printing and an inoperative position in which the paper 22 can be released from the printing zone 120. The chassis 60 and channel 62 are connected to the pinch roller 118 with suitable metalwork 130. Further, the chassis 60 and channel 62 are connected to the crossbar 128. It follows that, when the displacement mechanism 129 is operated, the pinch roller 118 and the spiked wheels 126 are displaced from the upper platen 106 together with the chassis 60 and the channel 62. The displacement mechanism 129 includes a camshaft 132 and a pusher 134. The pusher 134 is connected to the chassis 60 and the channel 62 so that, upon rotation of the camshaft 132, the chassis 60 and channel 62 are displaced towards and away from the printing zone of the upper platen 106. Upper idler rollers 136 are rotatably mounted above the upper platen 106 so that the paper 22 is received between the upper platen 106 and the upper idler rollers 136. A lower, sprung idler roller 138 is mounted on the lower platen 108 to be partially received through a gap 140 defined in the lower platen 108. The sprung idler roller 138 is configured and positioned to bear against the lower primary roller 112. Thus, an upwardly moving portion of the paper 22 is gripped, and passes between, the lower primary roller 112 and the sprung idler roller 138. The print assembly 14 includes a cutting mechanism 142 that is mounted in the housing 100 above the cutting zone 122 of the upper platen 106. The cutting mechanism includes a cutter 146 that traverses the paper 22 to cut the paper 22. The cutting mechanism 142 includes an optical sensor 144 so that the cutter 146 can be stopped when it reaches an end of a cutting stroke. The cutting zone 122 defines a cutting formation 148 that cooperates with the cutter 146 to facilitate cutting of the paper 22. As can be seen in FIG. 6, the print assembly 14 includes an air impeller 150 and a motor 152 to drive the air impeller 150. The air impeller 150 serves to generate an air current within the housing 100 for cooling purposes. An air filter 153 is also positioned in the housing 100 to filter the air passing through the housing 100. The air impeller 150 also serves to generate the air current to a sufficient extent to minimize the build up of dust on the printhead modules 46. As can further be seen in FIG. 6, the primary rollers 110, 112 are connected to a gearbox 154 that is mounted on a bracket 156. The gearbox 154 and bracket 156 are positioned on one of the legs 18 and covered with one of the end moldings 34. Thus, the primary rollers 110, 112 serve to drive the paper 22 through the print assembly 14. A printhead bracket 157 is positioned in the housing 100 and extends between the legs 18. The printhead bracket 157 provides a support structure for the chassis 60 and channel 62. The printhead bracket 157 also provides a support structure for the upper idler rollers 136. The housing 100 is shaped to define an opening 158 for passage of the paper 22 into and out of the print assembly 14. Feed rollers 162 are rotatably mounted on a tie bar 160 that extends between the legs 18. The feed rollers 162 are positioned so that the paper 22 passes over the feed rollers 162 when the paper is fed into the print assembly 14. The tie bar 160 also serves a structural purpose in that it provides structural rigidity to the printer 10. Discharge rollers 164 are rotatably mounted on the upper platen 106. The discharge rollers 164 are positioned so that the paper 22 passes over the discharge rollers 164 when the paper 22 is fed from the print assembly 14. Both the media roll 166 and the take up spool 24 are driven with a media roll drive motor 168 and a take up spool drive motor 170, respectively (FIG. 5). The printer 10 includes a power supply unit 172 that is positioned in the electronics enclosure 26. The power supply unit 172 is configured to be powered by either a 110V or 220V power supply. Further, the power supply unit 172 is configured so that up to 90 Amps can be drawn from the power supply unit 172. The power supply unit 172 is connected with power cables 173 to various components of the printer 10, such as the various drive motors to supply the components with required operational energy. The printer 10 includes an ATX motherboard 174 that is also positioned in the electronics enclosure 26. A printhead interface card 176 is mounted on the motherboard 174. The printhead interface card 176 is connected to the nine PCB's 42 with suitable data cables 178. Thus, conventional print data supplied to the interface card 176 from the motherboard 174 can be converted into a suitable form for reading by the various PCB's 42. The printer 10 includes a hard drive unit 180. Conveniently, the hard drive unit 180 can have a capacity of 40 Gigabytes. This facilitates the storage of entire images to be printed. The hard drive unit 180 is connected to the motherboard 174 in a conventional fashion. The hard drive unit 180 is a conventional hard drive unit and is therefore capable of storing images in any number of formats, such as the well-known JPEG format. The manner in which the image data is read from the hard drive unit 180 is also conventional. As is set out below, printing of the images is digitally controlled as a result of the printhead technology utilized in this invention. It follows that transferal of image data from the hard drive unit 180 to the PCB's 42, via the printhead interface card 176 can take place without the requirement of significant data transformation, in particular, without the requirement of digital to analogue signal conversion. The interface card 176 is also connected to a motor and LCD controller PCB 182 to control operation of the various drive motors and the TFT LCD. Details of such control are set out in the above referenced applications and are therefore not provided in this description. The motor and LCD controller PCB 182 is connected to a cut off switch 184 that is, in turn, connected to the stop button 38 so that operation of the printer 10 can be halted. As can be seen in FIG. 14, the printhead modules 46 each include a printhead chip 186. The printhead chip 186 can be in the form of any of the printhead chips described in the above referenced applications/patents. Each printhead module 46 includes a carrier 187 in which the printhead chip 186 is positioned. The carrier 187 defines a suitable connection zone for the flexible PCB 58 associated with the printhead chip 186. FIG. 13 shows a schematic diagram of part of a printhead chip 186 that is suitable for use in the printer 10. Each printhead module 46 includes what are known as on chip fiducials 258. The on chip fiducials 258 are essentially in the form of markers to facilitate accurate alignment of the printhead modules 46 in the print assembly 14. The printhead chip 186 is described in detail in the above referenced U.S. Pat. No. 6,416,167 and will therefore not be described in such detail in this specification. Briefly, however, the chip 186 includes a wafer substrate 188. A CMOS drive circuitry layer 190 is positioned on the wafer substrate 188 and is connected to the flexible PCB 58. A plurality of nozzle arrangements 210 is positioned on the CMOS drive circuitry layer 190. For the purposes of convenience, one such nozzle arrangement 210 is shown in FIG. 13. The printhead chip 186 comprises a multiple replication of the nozzle arrangement 210 on the wafer substrate 188. As set out in the above referenced applications and patents, the printhead chip 186 is the product of an integrated circuit fabrication technique. Replication of components in order to achieve a product is a well-known feature of such a fabrication technique. It follows that the printhead chip 186 can readily be understood by a person of ordinary skill in the field of chip fabrication. Each nozzle arrangement 210 includes a thermal bend actuator 192 that is positioned on the CMOS layer 190 to receive an actuating signal from the CMOS layer 190. In particular, the thermal bend actuator 192 includes a support post 194 that is mounted on the CMOS layer 190 to extend from the CMOS layer 190. The thermal bend actuator 192 includes an actuator arm 196 that is fixed to, and extends from, the support post 194. The actuator arm 196 includes a heating layer 198 in the form of an electrical heating circuit of a material having a coefficient of thermal expansion that is such that the material is capable of performing useful work on a MEMS scale as a result of expansion upon heating. The heating layer 198 is positioned on a layer 200 of a material having a coefficient of thermal expansion that is less that that of the heating layer 198 defining the electrical heating circuit. The heating layer 198 is positioned intermediate the layer 200 and the substrate 188 so that the actuator arm 196 is bent away from the substrate 188 when a current is passed through the heating layer 198. Nozzle chamber walls 202 are positioned on the CMOS layer 190. A roof wall 204 is positioned on the nozzle chamber walls 202. The nozzle chamber walls 202 and the roof wall 204 define a nozzle chamber 206. The roof wall 204 defines an ink ejection port 208 from which ink is ejected, in use. A paddle member 212 is mounted on the actuator arm 196 to extend into the nozzle chamber 206. The paddle member 212 is configured and positioned in the nozzle chamber 206 so that, upon displacement of the actuator arm 196, as described above, ink is ejected from the nozzle chamber 206. The actuator arm 196 is connected to the CMOS layer 190 through the support post 194 so that the heating layer 198 can receive an electrical signal from the CMOS layer 190. As can be seen in FIGS. 3 and 9, the printhead chips 186 are each positioned at an angle with respect to a straight line running the length of the printing zone 120. This facilitates a measure of overlap at adjacent ends of the printhead chips 186 to ensure printing continuity. It is clear from the above referenced United States applications and patents that a pagewidth printhead including printhead chips as described above can incorporate up to 84000 nozzle arrangements. It follows that, by using the printhead chips 186, it is possible for the print assembly 14 to have over as many as 200000 nozzle arrangements. It follows that over 200000 dots can be printed on the paper 22 in the printing zone 120. In one particular example, the seventy-two printhead chips 186 provide a print width of 57.6 inches with 552960 nozzle arrangements 210. The nozzle arrangements 210 of each chip 186 are positioned side-by-side in two rows in a staggered fashion. It follows that true 1600 dpi printing can be achieved with the printhead chips 186. Each printhead chip 186 therefore includes 7680 nozzle arrangements 210. Each nozzle arrangement 210 is independently controlled by the PCB 42 to eject a 1-picolitre drop on demand. The integrated circuit fabrication technology used is based on Very Large Scale Integration (VLSI) technology that is fully described in the above referenced applications and patents. As a result of the manufacturing techniques used, each nozzle arrangement 210 can be as little as 32 microns wide. This allows each printhead chip 186 to have a surface area as little as 21 mm2. The characteristics of each nozzle arrangement 210 are such that it is capable of being driven at a cyclical rate of up to 80 kHz by its associated PEC 48. This permits printing of up to 21.6 billion drops per second that provides thirty-five thousand square feet per hour at 1600 dpi. Each printhead chip 186 is connected to its associated PCB 42 with the flexible PCB 58. It follows that each flexible PCB 58 is connected to the CMOS layer 190 of its associated printhead chip 186. Each PEC 48 is a page rendering engine application specific integrated circuit (ASIC) that receives input data relating to compressed page images from the printhead interface 176. The PEC 48 produces decompressed page images at up to six channels of bi-level dot data as output. It will be appreciated that each PEC 48 communicates with eight printhead chips 186 in this example. Each PEC 48 is capable, however, of communication with up to sixteen such printhead chips 186. In particular, each PEC 48 can address up to sixteen printhead chips in up to six color channels at 15000 lines/sec. It follows that each PEC 48 allows for a 12.8-inch printhead width for full bleed printing of A3, A4 and letter pages. Each PEC 48 is color space agnostic. This means that the PEC 48 can accept print data in any color. While each PEC 48 can accept contone data as CMYX or RGBX where X is an optional fourth channel, it can also accept contone data in any print color space. Additionally, each PEC 48 is configured to define a mechanism for arbitrary mapping of input channels to output channels. The PEC 48 is also configured for combining dots for ink optimization and the generation of channels based on any number of other channels. In this example, data input is typically based on CMYK for contone printing, K for a bi-level input, fixative, and optional further ink channels. The PEC 48 is also configured to generate a fixative channel for fast printing applications. Each PEC 48 is configured to be resolution agnostic. This means that each PEC 48 simply provides a mapping between input resolutions and output resolutions by means of various scale factors. In this example, the expected output resolution is 1600 dpi. However, the PEC 48 does not store any data to this effect. Each PEC 48 is also configured to be page-length agnostic. Each PEC 48 operates a printing band at a time and a page can have any number of bands. It follows that a “page” can have any reasonable length. Each PEC 48 defines an interface so that it can be synchronized with other PEC's 48, as is the requirement with this invention. This allows a simple two-PEC solution for simultaneous A3/A4/Letter duplex printing. This also allows each PEC 48 to be responsible for the printing of only a portion of a page. It will be appreciated that combining synchronization functionality with partial page rendering allows multiple PEC's to be readily combined for alternative printing requirements including simultaneous duplex printing, wide format printing, commercial printing, specialist high contone resolution printing, and printing applications where more than six ink channels are required. The following table sets out the features of each PEC 48 and its associated benefits. TABLE 1 Features and Benefits of PEC Feature Benefits Optimized print architecture in 30 ppm full page photographic quality color printing from a hardware desktop PC 0.18micron CMOS High speed (>3 million transistors) Low cost High functionality 1.8 billion dots per second Extremely fast page generation 15,000 lines per second at 1600 dpi 1.1 A4/Letter pages per PEC chip per second 1 chip drives up to 122,880 nozzles Low cost page-width printers 1 chip drives up to 6 color planes 99% of printers can use 1 chip per page Sophisticated internal memory Only requires 1 external memory, leading to low cost buffering and caching systems JPEG expansion low bandwidth from PC low memory requirements in printer Lossless bitplane expansion high resolution text and line art with low bandwidth from PC (e.g. over USB) Netpage tag expansion Generates interactive paper Stochastic dispersed dot dither Optically smooth image quality No moire effects Hardware compositor for 6 image Pages composited in real-time planes Dead nozzle compensation Extends printhead life and yield Reduces printhead cost Color space agnostic Compatible with all inksets and image sources including RGB, CMYK, spot, CIE L*a*b*, hexachrome, YCrCbK, sRGB and other Color space conversion Higher quality/lower bandwidth Computer interface agnostic Works with USB1, USB2, IEEE1394 (Firewire), ethernet, IEEE1284 (Centronics) Variable page length Print any page length (up to 64 km) Cascadable in resolution Printers of any resolution Cascadable in color depth Special color sets e.g. hexachrome can be used Cascadable in image size Printers of any width Cascadable in pages Printers can print both sides simultaneously Cascadable in speed Very high speed printers can be built Fixative channel data generation Extremely fast ink drying without wasteage Built-in security Revenue models are protected Undercolor removal on dot-by-dot Reduced ink useage basis Does not require fonts for high No font substitution or missing fonts speed operation Flexible printhead configuration Many configurations of printheads are supported by one chip type Drives Memjet ™ printheads No print driver chips required, results in lower cost directly Determines dot accurate ink usaege Removes need for physical ink monitoring system in ink cartridges In FIG. 10, there is shown a block diagram of the PEC 48. The PEC 48 includes a micro controller interface in the form of a high-speed interface 214 through which an external micro controller 216 can write to the 64 Mbit DRAM chip 50. The high-speed interface 214 forms part of a data input means of the PEC 48. The PEC 48 also includes a control circuitry interface in the form of a low speed serial interface 220 through which the micro controller 216 can access registers of the PEC 48 and the DRAM chip 50. The PEC 48 also includes page expansion circuitry in the form of a page expansion unit (PEU) 222 that receives data relating to compressed pages and renders it into data relating to bi-level dots. Line loader and line formatter circuitry in the form of a line loader/formatter unit 224 is also provided that formats dots for a given print line destined for a printhead interface 226 that communicates directly with the printhead chips 186 of each printhead module 46. As can be seen, the PEC 48 performs three basic tasks. These are: a) Accepting register and DRAM access commands via the low speed interface 220 (or from the external DRAM chip 50). b) Accepting DRAM write accesses (typically compressed page bands and register command blocks) via the high speed interface 214. c) Rendering page bands from the external DRAM chip 50 to the printhead chips 186. These tasks are independent. However, they do share the external DRAM chip 50. It follows that arbitration is required. The PEC 48 is configured so that DRAM accesses required for rendering page bands always have the highest priority. The PEC 48 includes control circuitry in the form of a PEC controller 228 that provides external clients with the means to read and write PEC registers, and read and write DRAM in single 32 bit data chunks. The DRAM chip 50 is connected to memory storage control circuitry in the form of an SDRAM controller 234. In turn, the SDRAM controller 234 is connected to memory storage control circuitry in the form of a DRAM interface unit 236. The PEC 48 includes a data bus 230 and a low speed serial bus 232. Both the SDRAM controller 234 and the DRAM interface unit 236 are connected to the low speed serial bus 232. The PEC controller 228 is connected to the data bus 230. The PEC controller 228 is also connected to the low speed serial bus 232 via the low speed interface 220. The high-speed interface 214, the PEU 222 and the line loader/formatter unit are also connected to the data bus 230. In use, since the PEC 48 prints page bands from DRAM, a given band B is loaded into DRAM via the high-speed interface 214 before printing can begin. Then, while the PEC 48 is rendering band B via the PEU, band B+1 can be loaded to DRAM. While band B+1 is being expanded and printed, band B+2 can be loaded, and so on. In the following table, the various components of the PEC 48 mentioned above are described briefly. TABLE 2 Units within PEC (high level) unit reference acronym unit name numeral description DIU DRAM interface unit 236 Provides the interface for DRAM read and write access for the various PEC units. The DIU provides arbitration between competing units and passes on DRAM requests to the SCU. HSI High speed interface 214 Provides external clients (such as the microcontroller) with the means to write to DRAM. LLFU Line loader formatter 224 Reads the expanded page image from line unit store, formatting the data appropriately for the Memjet printhead. LSI Low speed interface 220 Provides external clients with the means to send commands to the PCU and receive register reads. PCU PEC controller 228 Provides external clients with the means to read and write PEC registers, and read and write DRAM in single 32-bit chunks. PEU Page expansion unit 222 Reads compressed page data and writes out the decompressed form of the same to DRAM. PHI Printhead interface 226 Is responsible for sending dot data to the Memjet printhead segments and for providing line synchronization between multiple PECs. SCU SDRAM controller 234 Provides the DIU with access to the external unit DRAM. An expanded block diagram of the PEU 222 is shown in FIG. 11. In the following table, the various components of the PEU 222 are described briefly. TABLE 3 Units within Page Expansion Unit (high level) unit acronym unit name reference numeral description CDU Contone decoder unit 238 Expands JPEG compressed contone layer and writes decompressed contone to DRAM CLBI Contone line buffer 240 Provides line buffering between CRU interface and HCU CRU Contone reader unit 242 Reads expanded contone image from DRAM DNC Dead nozzle compensator 244 Compensates for dead nozzles by error diffusing dead nozzle data into surrounding dots. DWU Dotline writer unit 246 Writes out the 6 channels of dot data for a given printline to the line store DRAM HCU Halftoner compositor unit 248 Dithers contone layer and composites the bi-level spot 0 and position tag dots. LBD Lossless bilevel decoder 250 Expands compressed bi-level layer. SLBI Spot line buffer interface 252 Provides line buffering between LBD and HCU TE Tag encoder 254 Encodes tag data into line of tag dots. TLBI Tag line buffer interface 256 Provides line buffering between TE and HCU A first stage in page expansion occurs along a pipeline defined by the CDU 238/CRU 242, the LBD 250 and the TE 254. The CDU 238 expands a JPEG-compressed contone (typically CMYK) layer. The LBD 250 expands a compressed bi-level layer (typically K), and the TE 254 encodes data tags for rendering (typically in IR or K ink) at a later stage. The CLBI 240, the SLBI 252 and the TLBI 256 receive output data from this stage. The HCU 248 carries out a second stage. The HCU 248 dithers a contone layer and composites position tags and a bi-level spot0 layer over a resulting bi-level dithered layer. A data stream generated by the HCU 248 is adjusted to create smooth transitions across overlapping segments or printhead chips 186. The HCU 248 is configured so that a number of options exist for the way in which compositing occurs. This stage can produce up to six channels of bi-level data. It should be noted that not all six channels might be present on the printhead chips 186. For example, the printhead chips 186 may be CMY only, with K pushed into the CMY channels and IR ignored. Alternatively, the position tags mentioned above may be printed in K if IR ink is not available or for testing purposes. The DNC 244 carries out a third stage. In this stage, the DNC 244 compensates for dead nozzles in the printhead chips 186 by error diffusing dead nozzle data into surrounding dots. Bi-level, six channel dot-data (typically CMYK-IRF) generated in the above stages is buffered and written out to a set of line buffers stored in the off-chip DRAM via the DWU 246. In a final stage, the dot-data is loaded back from the DRAM, formatted for the printhead, and passed to the printhead interface 226 via a dot FIFO (not shown). The dot FIFO accepts data from the line loader/formatter unit 224 at pclk rate, while the printhead interface 226 removes data from the FIFO and sends it to the printhead chips 186 at a rate of either pclk/4, pclk/2 or pclk. FIG. 12 simply shows the PEC 48 incorporating the exploded PEU 222. The printing benefits associated with the printhead chips 186 are set out in detail in the above referenced applications and patents. However, some benefits are particularly important when applied to wide printing formats. A particular benefit is the high number of nozzle arrangements 210 per printhead chip 186. This facilitates extremely rapid printing in that a single print cycle can achieve an image band. It follow that it is not necessary for further print cycles to be used to fill in “missing” dots as is the case with a scanning printhead. The PEC's 48 provide the necessary synchronized control of the printhead chips 186 as described above. Furthermore, as is clear from a number of the above referenced applications and patents, for example U.S. Pat. No. 6,362,868, the printhead chips 186 allow for the conversion from analogue printing processes to fully digital processes. This allows for a substantial amount of flexibility and speed. Digital control of the printhead chips 186 is by means of the PEC's 48. The fact that the PEC's 48 digitally control the printhead chips 186 allows for the high printing speed of up to 21.6 billion drops per second. In particular, the need for separate printhead chip drivers is removed, which is key to the high printing speed of the chips 186. The incorporation of the CMOS layer 190 serves to integrate CMOS technology with MEMS technology on each printhead chip 186. It follows that at least one off-chip connection for each nozzle arrangement 210 is not required. It will be appreciated that such a requirement would make a printhead unreliable and cost-prohibitive to manufacture. A further important advantage associated with the printer 10 is that a width of the printing zone 120 is extremely small when compared to the length. In a particular example, the printing zone 120 can be as little as 0.5 mm thick. It will be appreciated that it is necessary to achieve extremely stable paper movement through the printing zone 120 in order to ensure that accurate printing takes place in the printing zone. The narrow width of the printing zone 120 facilitates minimal control over the paper 22 as it passes through the printing zone. In the event that a substantially wider printing zone were provided, it would be necessary to provide further control over movement of the paper 22 through such a printing zone. This would require such devices as vacuum platens to retain the paper 22 against any form of pivotal or lateral movement as the paper 22 moves through the printing zone. This could greatly increase the cost of the wide format printer. This highlights some reasons why thermal or bubble jet and piezoelectric printheads would not be practical choices when attempting to achieve the printing characteristics of the printer 10. As set out in the above referenced applications and patents, such printheads are not suitable for providing the high density of nozzle arrangements achieved with the printheads of the above referenced matters. It follows that, in attempting to apply thermal and piezoelectric printheads to a wide format printer, it would be necessary to have a relatively wide printing zone so that overlapping of printheads could occur to the necessary extent. This would immediately raise the problem mentioned above. Still further, especially with the thermal printheads, a suitable cooling system would be required to keep the temperature in the printing zone at a reasonable level. This would also increase the cost to an unacceptably high level. In order to achieve an appreciation of the speed of the printer 10 at a resolution of 1600 dpi, the following comparative table is set out below. It should be noted that the purpose of the following table is simply to illustrate the speed of printing and is not intended to denigrate the various printers used for comparison. Wide Format Printers Memjet OEM Printhead 38.4 44.8 51.2 57.6 64.0 70.4 76.8 Print Width (inches) Number of 48 56 64 72 80 88 96 Printhead Chips Number of Nozzles 368,640 430,080 491,520 552,960 614,400 675,840 737,280 Max. print speed 17,578 20,508 23,438 26,367 29,297 32,227 35,156 (sq ft/hr at 1600 × 1600 dpi) Make Model Resolution Speed Speed Advantage (# of times faster) Comparison HP 1000/5000 600 × 600 120 146 171 195 220 224 269 293 HP 3000/3500 600 × 300 72 244 285 326 366 407 448 488 Epson 7000/10000 720 × 720 90 195 226 260 293 326 358 391 Encad Novajet 800 600 × 600 96 183 214 244 275 305 336 366 Gretag Arizona Draft mode 444 40 46 53 59 66 73 79 Gretag Arizona 309 × 618 220 80 93 107 120 133 146 160 Colorspan Mach X11 600 × 600 115 153 178 204 229 255 280 306 Canon BJW 9000 600 × 1200 72 244 285 326 366 407 448 488 Mutoh Albatross 792 × 792 65 270 316 361 406 451 496 541 Roland HiFi Jet 720 × 720 96 183 214 244 275 305 336 366 Nur Fresco 360 × 360 300 59 68 78 88 98 107 117 As is known by those of skill in the fabrication of integrated circuits, while a set up cost for the manufacture of an integrated circuit device can be high, the cost of commercial manufacture of such devices is relatively low. It follows that Applicant envisages that the cost of manufacture of a wide format printer in accordance with this invention will be comparable to the cost of manufacture of the wide format printers listed in the above table. It will be apparent to those skilled in the art that many obvious modifications and variations may be made to the embodiments described herein without departing from the spirit or scope of the invention.
|
B
|
B41
|
B41J
|
2
|
04
|
|||
11768747
|
US20080036145A1-20080214
|
METHOD FOR PLAYING A GAME
|
ACCEPTED
|
20080130
|
20080214
|
[]
|
A63F300
|
["A63F300"]
|
7571911
|
20070626
|
20090811
|
273
|
243000
|
88219.0
|
MENDIRATTA
|
VISHU
|
[{"inventor_name_last": "Lim", "inventor_name_first": "Clinton", "inventor_city": "Singapore", "inventor_state": "", "inventor_country": "SG"}]
|
A game includes a board having a start position and at least two possible finish positions. A number of sequential positions are located between the start position and the possible finish positions. Each player has a playing piece which starts on the start position and a player designating one of the finish positions prior to starting the game. The game finishing when a player's playing piece lands on the designated finish position.
|
1. A method of playing a game comprising providing a number of representations of functions of the brain, and acquiring a minimum number of functions in order to win the game. 2. A method according to claim 1, wherein the representations include functions of the left side and the right side of the brain, and functions from both sides of the brain must be acquired to win the game. 3. A method according to claim 1 or claim 2, wherein a function is acquired by purchasing the function. 4. A method according to any of claims 1 to 3, wherein a function is acquired by picking up a card relating to the function.
|
<SOH> BACKGROUND <EOH>The invention relates to apparatus and methods for playing a game.
|
<SOH> SUMMARY <EOH>In accordance with a first aspect of the present invention, there is provided apparatus for playing a game comprising a board marked substantially as shown in the drawings, and one or more playing pieces, the playing pieces being moved in accordance with directions in the specification. In accordance with a second aspect of the present invention, there is provided a game comprising a board having a start position and at least two possible finish positions and a number of sequential positions located between the start position and the possible finish positions, each player having a playing piece which starts on the start position, a player designating one of the finish positions prior to starting the game, and the game finishing when a player's playing piece lands on the designated finish position. In accordance with a third aspect of the invention, there is provided a method of playing a game comprising providing a number of representations of functions of the brain, and acquiring a minimum number of functions in order to win the game.
|
CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a divisional U.S. Utility application Ser. No. 10/502,374, filed Jul. 23, 2004, entitled Apparatus For Playing A Game, which was the National Phase of International Application No. PCT/SG02/00010, filed Jan. 23, 2002. BACKGROUND The invention relates to apparatus and methods for playing a game. SUMMARY In accordance with a first aspect of the present invention, there is provided apparatus for playing a game comprising a board marked substantially as shown in the drawings, and one or more playing pieces, the playing pieces being moved in accordance with directions in the specification. In accordance with a second aspect of the present invention, there is provided a game comprising a board having a start position and at least two possible finish positions and a number of sequential positions located between the start position and the possible finish positions, each player having a playing piece which starts on the start position, a player designating one of the finish positions prior to starting the game, and the game finishing when a player's playing piece lands on the designated finish position. In accordance with a third aspect of the invention, there is provided a method of playing a game comprising providing a number of representations of functions of the brain, and acquiring a minimum number of functions in order to win the game. DESCRIPTION OF THE DRAWINGS An example of apparatus for playing a game in accordance with the invention will now be described with reference to the accompanying drawings, in which: FIG. 1 is a plan view of a board; FIG. 2 shows a large brain playing piece; FIG. 3 shows a small brain playing piece; FIG. 4 shows a circular brain counter; FIGS. 5a to 5d show examples of procrastination cards; FIGS. 6a to 6c show examples of learning cards; FIGS. 7a to 7f show examples of self-booster cards; and FIGS. 8a to 8c show example of synergy cards. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Certain terms are used throughout the following description and claims to refer to particular system components. This document does not intend to distinguish between components that differ in name but not function. Preferably, the sequential positions comprises a number of purchasable positions, at least one of which must be purchased by a player during the game in order for a player to win the game. Typically, the apparatus may also comprise a set of cards which provide a player with additional instructions. Preferably, a player takes a card when the player's playing piece lands on a corresponding sequential position on the board. Preferably, there may be more than one set of cards, each set of cards being associated with specified sequential positions of the board such that when a player's playing piece lands on a specified sequential position, the player takes a card from the set of cards corresponding to the specified position. Typically, the sequential positions are divided into at least two sections, each section corresponding to a level of the game. Preferably, a player must complete the first level before proceeding to the second level. Typically, the start position is on the first level and the possible finishing positions are on the second level. Typically, the game may be played by two to six players. However, it is possible that it may be played by more than six players. Preferably, a player's playing piece proceeds round the board by moving the number of places shown by a dice (or die) rolled by the player. Typically, the layout of the sequential positions on the board depicts the brain with the first level forming the left side of the brain and the second level forming the right side of the brain. Typically, the possible finish positions correspond to desired destiny chosen by a player. Preferably, the purchasable positions in the first level comprise the main functions of the left brain: logic; words; analysis; listing; sequence; linearity; and numbers. Preferably the purchasable positions in the second level comprise the main functions of the right brain: rhythm; colour; dimension; spatial awareness; daydreaming; imagination; and holistic awareness. In one example of the invention, the game may be implemented using a real physical board and playing piece. However, in another example of the invention, the game may be implemented as an electronic game with the board and playing piece represented on a display device, such as a visual display unit. Where the game also includes cards and money, these may also be electronic and represented on the display device. Preferably, the representations include function of the left side and the right side of the brain, and functions from both sides of the brain must be acquired to win the game. Typically, a function may be acquired by purchasing the function or by picking up a card relating to the function. FIG. 1 shows a board 10. The board includes a left brain section 11 and a right brain section 12 which each include sequential positions along which a playing piece 21 (see FIG. 3) can be moved. In addition, the board 10 has positions 13, 14, 15, 16 marked. On each portion 13-16, set of cards 23, 24, 25, 26 may be placed containing additional instructions for players playing the game. A set of procrastination cards 23 are placed on the portion 13, a set of self-booster cards 24 are placed on the portion 14, a set of learning cards 25 are placed on the portion 15 and a set of synergy cards 26 are placed on the portion 16. Examples of procrastination cards 23 are shown in FIGS. 5a to 5d, examples of learning cards 25 are shown in FIGS. 6a to 6c, examples of self-booster cards 24 are shown in FIGS. 7a to 7f and examples of synergy cards 26 are shown in FIGS. 8a to 8c. In order to play the game, each player is provided with a large brain playing piece 20 (see FIG. 2) and a small brain playing piece 21 (see FIG. 3) and a number of circular brain counters 22 (see FIG. 4). Each of the playing pieces 20, 21 and the counter 22 are of the same colour for each player and each player's colour is different from that of the other players. In addition, each player is provided with $500,000 of play money. The game is played using the board 10, the playing pieces 20, 21, the circular counters 22 and the sets of cards 13, 14, 15, 16 in accordance with the rules set out below. Rules 1. Any number, from 2-6 players can play 2. A “banker” is appointed. A player may double-up as a “banker”. 3. Each player starts with a capital of $500,000 of play money from the banker. 4. The game commences with each player deciding which ambition (or goal in life) they wish from the ambitions 31 on the right brain section 12—doctor, engineer, author, school principal, entertainer, scientist, lawyer, entrepreneur or to achieve financial freedom. Left Brain 5. Each player chooses two brains 20, 21 of the same colour. The smaller brain is placed at “start” 30 on the left brain 11 and the other larger brain 20 at the site of the chosen ambition 31 on the right brain 12. 6. The challenge is to quickly get out of the “left brain” 11 so that you can advance to play on the “right brain” 12. To do this you must: i) purchase the “right brain” site 32 plus any 4 different 7 “left brain” activities 33; or ii) acquire any 5 different 7 “left brain” activities 33 plus paying $75,000 to the banker. 7. A circular brain counter 22 of the player's colour is placed on each site 32, 33 purchased by a player. 8. A player may purchase as many “right brain” sites 32 as they wish for $100,000 per site, provided that the player stops on it each time and by paying this amount to the banker. If a player does not have sufficient funds, the player may borrow from the banker at an interest rate of 10% per annum, payable upfront (banker issues $90,000 for a $100,000 loan). Debts must be settled in full, before a player can be declared the winner. 9. A player is permitted to sell a “right brain” site 32 (if the player has purchased more than one), to any other player on a “willing-buyer-willing-seller” basis. The maximum amount a player is allowed to charge for it is $200,000. 10. A player may purchase more left brain activity sites 33 than the player requires (at $25,000 each) and then sell the additional sites to another player at a profit not exceeding 100% per site. 11. On stopping at “LEARNING” 35 or “PROCRASTINATION” 36, a player is required to take the appropriate card 25, 23 and follow its instruction before proceeding to collect the reward. Fines are to be paid in cash. Right Brain 12. A player is permitted to play on the “right brain” 12 provided the player has fulfilled condition 6(i) or 6(ii). When 6(i) or 6(ii) are fulfilled, the small brain playing piece 21 is moved to the “Advance to Right Brain” 34. 13. On stopping at “SELF-BOOSTER” 37 or “SYNERGY” 38, a player is required to take the appropriate card 24, 26 and follow its instructions, before collecting the reward. 14. A player may purchase one or more right brain activity sites 39, and may purchase more sites than the player. Each site 39 is $30,000 each. Excess sites 39 may be sold to another player at a profit not exceeding 100% per site. 15. A circular brain counter 22 of the player's colour is placed on each site 39 purchased by that player. Declaration of Winner 16. There are three possible ways in which a player may be declared the winner: i) A player is playing on the right brain and has acquired all seven activities 39: rhythm colour spatial awareness dimension imagination daydreaming holistic awareness; or ii) A player stops on the site 31 of his chosen ambition; or iii) A player is playing on the right brain and at a prior agreed “stop time”, has amassed the most amount of assets and money. Although, as described above the game uses a real physical board 10, playing pieces 20, 21, 22, sets of cards 23, 24, 25, 26 and play money, it is possible is that the game could be implemented electronically, for example, using a computer and software. In this case, the board, playing pieces, sets of cards, and play money may be represented on a display coupled to the computer, and the game played by entering appropriate instructions into the computer. For example, the playing pieces may be moved across the board using a mouse or key board.
|
A
|
A63
|
A63F
|
3
|
00
|
|||
11899216
|
US20080004738A1-20080103
|
Systems and method providing for remote system design
|
ACCEPTED
|
20071218
|
20080103
|
[]
|
G06F1900
|
["G06F1900"]
|
7428441
|
20070905
|
20080923
|
700
|
097000
|
63121.0
|
VON BUHR
|
MARIA
|
[{"inventor_name_last": "Walters", "inventor_name_first": "Eric", "inventor_city": "Modesto", "inventor_state": "CA", "inventor_country": "US"}]
|
A two-way communication and data transfer system allows a field technician and a designer to work together to create a retrofit design for a flow system, make a cost estimate for the retrofit, and gather an approval from a customer all in a single visit to the customer site. The field technician can utilize a remote unit including a digital camera, data entry device, and communication device, which allows the technician to transfer images and dimension information about the existing system to a base unit. A designer can take this information from the base unit and generate a virtual design for a new system, allowing a virtual view and cost estimate to be generated for display to the customer. The technician and the designer can communicate during the process to improve the accuracy of the design and estimate.
|
1. A method of retrofitting elements of an existing circulation system for a pool in order to improve fluid flow comprising the steps of: obtaining a plurality of measurements at a pool site in order to characterize the existing circulation system; inputting the measurements into a data entry device; using the data entry device, transmitting the measurements to a technician at a remote design location; at the remote design location, creating a virtual design for the retrofit based on the measurements, said virtual design including new fittings and piping configured to improve fluid flow through the circulation system; and transmitting information related to the virtual design back to the pool site. 2. A method as recited in claim 1, further including the steps of: at the remote design location, generating pricing information sufficient to generate a cost estimate for the retrofit; and transmitting the pricing information to the pool site. 3. A method as recited in claim 1, further including the step of transmitting an image of the virtual design from the remote design location to the pool site for approval. 4. A method as recited in claim 1, further including the steps of: building a retrofit kit based on the virtual design including the new fittings and pipings; delivering the retrofit kit to the pool site; and installing the retrofit kit into the circulation system at the pool site. 5. A method as recited in claim 1, further including the step at the pool site of generating an image of the circulation system and transmitting said image to the remote design location for use in creating the virtual design. 6. A method as recited in claim 1, further including the step of establishing a verbal communication link between the remote technician and an installer at the pool site to facilitate transfer of additional information about the pool to the remote technician. 7. A method of retrofitting elements of an existing circulation system for a pool in order to improve fluid flow comprising the steps of: obtaining a plurality of measurements at a pool site in order to characterize the existing circulation system; obtaining an image of the existing fittings; transmitting the image and the measurements to a technician at a remote design location; at the remote design location, creating a virtual design for the retrofit based on the image and the measurements, said virtual design including new fittings and piping configured to improve fluid flow through the circulation system; transmitting information related to the virtual design back to the pool site. 8. A method as recited in claim 7, further including the steps of: at the remote design location, generating pricing information sufficient to generate a cost estimate for the retrofit; and transmitting the pricing information to the pool site. 9. A method as recited in claim 7, further including the step of transmitting an image of the virtual design from the remote design location to the pool site for approval. 10. A method as recited in claim 7, further including the steps of: building a retrofit kit based on the virtual design including the new fittings and pipings; delivering the retrofit kit to the pool site; and installing the retrofit kit into the circulation system at the pool site. 11. A method as recited in claim 7, further including the step of establishing a verbal communication link between the remote technician and an installer at the pool site to facilitate transfer of additional information about the pool to the remote technician. 12. A method as recited in claim 7, further including the step of inputting the measurements obtained at the pool site into a data entry device and using the data entry device to transmit the measurements to the remote design location. 13. A method of retrofitting elements of an existing circulation system for a pool in order to improve fluid flow comprising the steps of: obtaining a plurality of measurements at a pool site in order to characterize the existing circulation system; transmitting the measurements to a design technician at a remote design location; establishing a communication link between the field technician and the design technician allowing additional parameters related to the pool site to be discussed; at the remote design location, creating a virtual design for the retrofit based on the measurements and the additional parameters, said virtual design including new fittings and piping configured to improve fluid flow through the circulation system; transmitting information related to the virtual design back to the pool site. 14. A method as recited in claim 13, further including the steps of: at the remote design location, generating pricing information sufficient to generate a cost estimate for the retrofit; and transmitting the pricing information to the pool site. 15. A method as recited in claim 13, further including the step of transmitting an image of the virtual design from the remote design location to the pool site for approval. 16. A method as recited in claim 13, further including the steps of: building a retrofit kit based on the virtual design including the new fittings and pipings; delivering the retrofit kit to the pool site; and installing the retrofit kit into the circulation system at the pool site. 17. A method as recited in claim 13, further including the step at the pool site of generating an image of the circulation system and transmitting said image to the remote design location for use in creating the virtual design. 18. A method as recited in claim 13, further including the step of inputting the measurements obtained at the pool site into a data entry device and using the data entry device to transmit the measurements to the remote design location.
|
<SOH> BACKGROUND <EOH>In many industries in which a flow of fluid is utilized, it is desirable to maximize flow, or minimize flow resistance, in order to reduce the amount of equipment runtime necessary to push through a given volume of fluid. By reducing the amount of runtime, the amount of wear and tear on the equipment can be reduced, and the cost of running the equipment can be significantly lowered. In industries such as the pool industry, for example, an increase in the throughput of water passed through a filter pump and recirculated through the pool can reduce the necessary runtime of the pump, thereby reducing the cost of gas or electricity necessary to run the pump. A major obstacle to flow in the pool industry is the use of standard piping components, such as 90° elbows, 45° fittings, unions, tees, and crosses, made from materials such as PVC and assembled with materials such as PVC cement, Teflon® tape, or silicone cement. While these basic elements are cheap and readily available at most hardware stores, they can result in sharp turns and other partial barriers that can lead to a significant reduction in flow, compared to a more linear or smooth run, as known in the art for flow of a fluid. A swimming pool can be retrofitted to provide for improved flow. Existing retrofits come with several disadvantages, however. One disadvantage is that the person doing the retrofit generally is limited to standard plumbing components in standard sizes and shapes. As such, only limited improvement can be obtained by redirecting the flow, such as flow from a suction pipe to the main circulation pump. Further, it takes a substantial amount of time to retrofit a plumbing installation. It typically is necessary for a salesman to go to the site and take measurements, then go offsite to determine the necessary piping and associated costs, then return to the client at a later time for approval, a signature, and a deposit. Subsequently, an installer will be sent in to dismantle the existing piping and equipment and install new components. The installer must build the new piping using standard parts, oftentimes using parts not carried on the installer's truck, such that the installer has to make at least one trip to the hardware store during installation. The installation also will require a significant amount of cutting and gluing, such that a standard installation can easily take over eight hours of time. The amount of time not only increases the cost of each retrofit, but lowers the number of pools that can be retrofitted in a given period of time by a single technician.
|
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 is a diagram of a communication system that can be used in accordance with one embodiment of the present invention. FIG. 2 shows diagrams of (a) an equipment system of the prior art and (b) an equipment system that can be designed using the communication system of FIG. 1 . FIG. 3 is a flowchart showing steps of a process that can be followed in accordance with various embodiments of the present invention. FIG. 4 is a flowchart showing steps of a process that can be followed in accordance with various embodiments of the present invention. FIG. 5 is a flowchart showing steps of a process that can be followed in accordance with various embodiments of the present invention. FIG. 6 is a flowchart showing steps of a process that can be followed in accordance with various embodiments of the present invention. detailed-description description="Detailed Description" end="lead"?
|
PRIORITY This continuation application claims priority to U.S. patent application Ser. No. 11/191,089, filed Jul. 27, 2005, which application is incorporated herein by reference. TECHNICAL FIELD OF THE INVENTION The present invention relates to the design of installations such as systems providing for fluid transport. BACKGROUND In many industries in which a flow of fluid is utilized, it is desirable to maximize flow, or minimize flow resistance, in order to reduce the amount of equipment runtime necessary to push through a given volume of fluid. By reducing the amount of runtime, the amount of wear and tear on the equipment can be reduced, and the cost of running the equipment can be significantly lowered. In industries such as the pool industry, for example, an increase in the throughput of water passed through a filter pump and recirculated through the pool can reduce the necessary runtime of the pump, thereby reducing the cost of gas or electricity necessary to run the pump. A major obstacle to flow in the pool industry is the use of standard piping components, such as 90° elbows, 45° fittings, unions, tees, and crosses, made from materials such as PVC and assembled with materials such as PVC cement, Teflon® tape, or silicone cement. While these basic elements are cheap and readily available at most hardware stores, they can result in sharp turns and other partial barriers that can lead to a significant reduction in flow, compared to a more linear or smooth run, as known in the art for flow of a fluid. A swimming pool can be retrofitted to provide for improved flow. Existing retrofits come with several disadvantages, however. One disadvantage is that the person doing the retrofit generally is limited to standard plumbing components in standard sizes and shapes. As such, only limited improvement can be obtained by redirecting the flow, such as flow from a suction pipe to the main circulation pump. Further, it takes a substantial amount of time to retrofit a plumbing installation. It typically is necessary for a salesman to go to the site and take measurements, then go offsite to determine the necessary piping and associated costs, then return to the client at a later time for approval, a signature, and a deposit. Subsequently, an installer will be sent in to dismantle the existing piping and equipment and install new components. The installer must build the new piping using standard parts, oftentimes using parts not carried on the installer's truck, such that the installer has to make at least one trip to the hardware store during installation. The installation also will require a significant amount of cutting and gluing, such that a standard installation can easily take over eight hours of time. The amount of time not only increases the cost of each retrofit, but lowers the number of pools that can be retrofitted in a given period of time by a single technician. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a communication system that can be used in accordance with one embodiment of the present invention. FIG. 2 shows diagrams of (a) an equipment system of the prior art and (b) an equipment system that can be designed using the communication system of FIG. 1. FIG. 3 is a flowchart showing steps of a process that can be followed in accordance with various embodiments of the present invention. FIG. 4 is a flowchart showing steps of a process that can be followed in accordance with various embodiments of the present invention. FIG. 5 is a flowchart showing steps of a process that can be followed in accordance with various embodiments of the present invention. FIG. 6 is a flowchart showing steps of a process that can be followed in accordance with various embodiments of the present invention. DETAILED DESCRIPTION Systems and methods in accordance with various embodiments of the present invention can overcome various deficiencies in existing approaches to designing and/or retrofitting systems such as systems providing for a flow of fluid. In one embodiment, a technician can collect information from a site that can be transmitted to a base location, where a design for a new system can be created, which can be relayed back to the technician for communication to a customer in a single customer meeting. The technician and persons at the base location can communicate during the design process in order to ensure an accurate design. In another embodiment, a new system can be designed on-site using information gathered by the technician. Once a system is selected and approved by the customer, an equipment kit can be generated that includes everything necessary to retrofit/convert the old system to the newly designed system or to install a new system. This allows an installer to quickly and easily do the work without the need to go offsite during installation for additional parts or to spend time cutting and cementing existing parts. Such approaches can reduce the amount of time the customer has to meet with a technician, allow designs to be generated and approved in a single visit, reduce the amount of travel time, and can allow a kit to be designed such that an installer visiting the site only has to view instructions and install the kit without having to gather parts and/or cut and cement existing parts. FIG. 1 shows a diagram of a communication and data transfer system 100 that can be used in accordance with various embodiments. The use of such a system will be discussed with respect to the retrofit of an existing pool equipment structure, but it should be understood that this is merely exemplary and should not be read as a limitation on the scope of the embodiments discussed herein. In a swimming pool example, a customer can request a quotation for a retrofit of the piping equipment for a backyard swimming pool. A field technician can be dispatched to meet the customer at a given time in the backyard of the customer. Once there, the customer can lead the technician to the pool and the equipment pad 102 containing various pool equipment, typically including a main pump 104 for circulating water through the pool, a filter 108 for catching fine debris or contaminants that may have slipped through a pool skimmer, and a heater 106 for heating the pool water to a desired temperature. The equipment pad also will have various runs of piping 110 connecting the various pieces of equipment and pipes running to and from the pool. The field technician can utilize a remote unit 120 to collect information about the pool equipment 102 to be retrofit. The remote unit can be a single self-contained device, or can include a number of separate devices that can be connected as necessary: If a remote unit contains a cellular phone for voice communications, for example, there may be no need for the cellular phone to be connected to the other components of the remote unit, particularly if the other components include a data transfer device capable of transferring information to a base unit. An exemplary remote unit can include an imaging device 122 allowing the technician to capture various images of the pool and the pool equipment 120. The imaging device can be any appropriate device known for capturing two- or three-dimensional images, such as a digital camera or laser scanner. The remote unit can include a data entry device 126, such as any of the various data entry devices known in the art such as a keyboard, mouse, joystick, stylus, or touch screen, allowing a technician having taken measurements of the pool and pool equipment to enter the information into the remote unit. In another embodiment, a scanner such as a laser scanner or radar device can be used to capture the information and dimension measurements together, such that a separate image capture device and data entry device may not be necessary. A data entry device still can be useful to input customer and other information. The remote unit can include a display device 128, such as a monitor, for allowing the technician to enter and/or view collected information, as well as to display the images and information to the customer. The remote unit can include a wireless device 124, such as a cellular phone and/or cellular modem, allowing the technician to upload the information and images to a base unit. The wireless device also can allow the technician to communicate with persons at the base unit, or a separate communications device such as a cellular phone can be used. If a cellular phone is used to transfer data from a laptop device, for example, then the cellular phone can have a data connection to the laptop. If data is transferred via a cellular modem of the laptop, then the cellular phone does not need to be connected to any other components of the remote unit. The remote unit can include a printer 130 allowing the technician to generate information such as a formal quotation, virtual view of the new equipment, and an analysis of cost savings, that can be given to the customer. The remote unit also can include a payment device 132, such as a credit/debit card reader, allowing the customer to approve the design and place a deposit or payment for the services. As discussed above, these components can take any of a number of configurations, such as a laptop computer with a cellular modem connected to a digital camera and printer. Another alternative utilizes a PDA phone allowing pictures to be taken with the internal camera phone, data to be entered into a spreadsheet on the device, the information to be transmitted by the device to the base unit, and communication with the base unit through a phone connection or another mechanism such as text messaging. In yet another embodiment, design software can be included in the PDA phone such that when the technician enters the information and captures the images, the design can be done internally through software, and the PDA phone can be used to display the proposal and generated information to the customer. The phone connection can have various uses, such as to ask questions of a designer or obtain approval of the design. At the headquarters or other location where the information will be received and the design created, in at least some embodiments, a base unit 140 can be used to receive the information. The base unit can include a communication device 144 capable of receiving information from the remote unit 120. The communication device can be any appropriate device, such as a modem, phone, or wireless device. The communication can not only accept information and mages from the remote unit, but can allow personnel at the base unit to communicate with the field technician. The communication unit can include separate devices, such as a modem for data communication and a phone for interpersonal communication. The base unit also can include a computer graphics program, virtual design studio, or other photo editing device 142 capable of taking the images from the imaging device 122 and either automatically, or manually with input from the personnel, generating a view of the new equipment installed at the actual customer site after the retrofit. The base unit can include a data entry device 146 allowing the personnel to use the photo editor, as well as to enter any additional information for the site and/or design. The base unit can include a display device 148, such as a standard monitor or a projection device allowing personnel to easily see the existing layout during the design process. The base unit also can include a payment device 152 allowing the customer to give verbal approval and account or other information, such as credit card number, whereby the personnel at the base unit can enter the information into the payment device. The base unit can include a parts and design kit 150. This can be an actual kit, made up of fittings and piping, or can be a virtual or computer generated kit, allowing a design to be generated through software. A combination also can be used, wherein a virtual design is made that the personnel attempt to build using the actual pieces, in order to determine if the design will work and/or if additional information is needed. A design kit allows personnel to design a system that will work for the given equipment specifications, whereby the personnel can determine the improvement in flow and necessary equipment costs. The equipment described with respect to FIG. 1 allows a field technician and personnel at a base unit to gather information and design a new flow system all in a single visit to the customer site (although multiple visits could be made as well, such as if the customer did not have time to wait for the design or wanted to discuss the project with a spouse before authorizing). The technician arriving at the location can find an existing equipment pad such as is shown in the prior art diagram of FIG. 2(a). The technician can measure and record dimensions such as the spacing of the return lines 202 exiting the cement pad, the distance to the pump 204, the distance from the outlet of the pump to the inlet of the filter 206, and the distance from the outlet of the filter 206 to the return line 208 in the cement pad. The technician also can measure vertical distances where needed, such as distances relative to the top surface of the cement pad, such that the design can be created accurately in three dimensions. By taking images of the equipment pad and sending them to the base unit, a designer at the base unit can determine whether there might be anything blocking a potential path that would not otherwise have shown up in the measurements, as well as to determine whether any additional measurements or information are needed. The images also allow the virtual design to be placed “in” the image of the equipment pad at the customer location, so customers can see what the equipment will look like in their backyards. For instance, after the virtual design 250 has been completed, as shown in the example of FIG. 2(b), a view of the piping and equipment can be dropped into the image showing the new pump 252 and filter 254 on the cement pad. The image also can show the new piping going between the equipment, as well as to the suction lines 258 and return line 260. Providing the designer with at least one image of the site allows the designer to more easily change the path of the piping. The designer can do away with T-junctions and 90° elbows, which can significantly reduce flow, and replace the existing piping with shaped piping runs that have no sharp turns and that can increase the overall flow of the system. For instance, the piping from the suction lines 202 in the prior art device include two 90° elbows, while the piping from the suction lines 258 in the new design includes a single rounded pipe with a much larger turning radius and no sharp turns, allowing the water to more easily flow to the respective pump. Increasing the flow not only provides the benefit of allowing the pump to run less to circulate the same amount of water, thereby reducing energy costs, but also allows for the use of higher efficiency pumps, which can further reduce energy costs. Pumps such as low head pumps or variable r.p.m. pumps, which can require a greater volume of flow through the circulating system, can reduce operating head pressure and allow for a significant reduction in kilowatt consumption. For example, the wattage of the pump generally can be reduced by a factor of four when the rpm value is reduced by a factor of two, per pump affinity laws. For a pump running at 3450 rpm and drawing ten Amps, a reduction to 1725 rpm will draw only 2.5 Amps. Volume of flow, on the other hand, is only reduced by a factor that is half the reduction factor for rpm, such that the pump in this example will provide 75% of the flow at 1725 rpm, compared to 100% flow at 3450 rpm. If head loss in an existing system can be reduced by 15-20%, such as by utilizing laminar flow piping, the resulting flow can be nearly equal to the full rpm. value, at only about 25% of the kilowatt consumption. FIG. 3 shows steps of an overall process 300 that can be used with use the system of FIG. 1 to generate a design such as that shown in FIG. 2(b). In such a process, a field technician takes a series of images useful for designing a new flow system 302, such as images of the equipment pad, existing equipment, the pool, and the surrounding area of the yard. As discussed above, these images can be any appropriate images, such as digital pictures or images created from at least one set of scan data. The technician also can take a series of measurements relating to the pool and equipment, if the measurements are not obtained by the scanner, and that information can be entered into the remote unit 304 to be sent to the base unit. If a three-dimensional scanner is used, dimension information can be transferred directly to a memory device of the remote unit for later transfer to the base unit. In this case, the data entry device can be used simply to input customer information to be stored in the memory device. In an alternative embodiment, customer data can be entered into a data entry device at the base unit before the technician is dispatched, such that there is no need for the technician to enter customer information and a data entry device may not be necessary. It also should be noted that various steps in this method can be done in any of a number of different orders, and that the listing in the method is not meant to imply a sequential order unless otherwise stated. For example, a technician can make measurements before, during, or after taking images, and can communicate with base unit personnel at any time during the process. Once entered or transferred into the remote unit, the measurement data and images can be transmitted to a base unit for processing 306, such as by uploading the pertinent data to the base unit via a cellular modem of the remote unit. The information can be received by the base unit, such as through another cellular modem, and can be stored in files, databases, or any other techniques known for storing information in an electronic, optical, magnetic, or other appropriate format. Personnel at the base unit can view and/or manipulate the information and images to be used in generating a virtual equipment setup 308. The base unit personnel and the technician can communicate with each other before and/or during the design process to discuss the information and images, as well as to gather any additional information needed to generate an accurate design 310. Once the virtual design is created, a new image can be generated including the proposed design setup, and information can be generated regarding equipment costs and energy savings 312. The new image(s) and information can be sent to the technician for display or other communication to the potential customer 314. The owner can select to authorize the work based on the image and information, all of which can have been generated during a single visit by the technician 316. From the design, a piping and equipment kit can be generated that includes everything (at least from a component standpoint) that a technician will need to retrofit the existing equipment pad. An installer then can install the kit using only basic tools and without the need to locate, cut, or otherwise obtain any additional parts during the installation process 318. In order to better explain such a process, individual steps of an exemplary process will be discussed below in further detail. These explanatory processes are not intended to limit the scope of the overall process, but only to explain the implementation of such a process in accordance with one embodiment. FIG. 4 shows steps of an exemplary process 400 by which a field technician can obtain information for an installation for which a design is to be generated. As discussed above, a field technician can take a series of images of the installation, which can include images of the equipment, the relationship of the equipment to the pool, parts to be retained or replaced, pipes of interest (such as the chase pipe, suction pipe, return pipe, and cleaner pipe), and the surrounding area 402. At least one of these images can be a top-down image of the equipment pad showing the relationship of the equipment and pool lines. Another image can shown the relationship of the pad to the pool. The number and type of images taken can vary by installation, but should be sufficient to show a view of each critical component necessary for the retrofit. The images can be taken with any appropriate imaging device, such as a digital camera or three-dimensional scanning device, which can be internal to the communication device used to send the information to the base unit, such as a cellular PDA phone with a built in camera, or can be separate but connected to, or otherwise in communication with, the communication device. In an alternative embodiment, a cellular phone with a built-in camera can be used to take and transfer images, as well as to provide for voice communication, but can be separate from a data entry device, and/or scanner, and data transfer device used to transfer dimension information. The field technician also can take a series of measurements 404, before, during, or after the capturing of the images. The number of measurements can vary by installation, and can be dependent upon factors such as the number of critical features, number of obstructions, and relative positions of the features and/or obstructions. Critical dimension measurements can include the horizontal and vertical distances between any fittings to which new piping is to be attached, such as the return pipe feed, heater, and/or risers coming out of the cement. Other critical measurements can include the available space on the pad once the old equipment has been removed. An exemplary minimal set of measurements can include the separation in two dimensions of the suction and return lines, as these positions typically are fixed in the cement pad unless the pad also is to be replaced. The measurements to be taken can be known by the technician beforehand, or can be prompted by software on the data entry device. For instance, a series of options of equipment types can be displayed to the technician, such that the technician can select the appropriate type. From that selection, a series of measurements can be requested by the software that guide the technician through the measurement process. If a scanner or radar is used, the software can guide the technician through the scanner placement process such that the necessary measurements can be captured. In order to generate a rough estimate of energy savings of a new installation, a field technician or base unit personnel can simply compare the kilowatt reduction in moving from an existing pump to the new pump. This rough estimate would not take into consideration the effect on flow of the piping improvement, which should easily add at least 10-15% to the savings due to the new pump. The technician can use an ammeter to take an amp reading for the main pump, as the actual value sometimes is different from what is printed on the pump label. In order to provide a more accurate estimate of energy savings, the field technician can gather information about the current flow rate of the pool equipment 406. In one embodiment, the technician can screw a vacuum gauge into a drain port on the existing pump, and can utilize a pressure gauge on top of the filter. The technician then can multiply the reading (in inches of mercury) on the vacuum gauge by 1.13 to obtain the head of the suction piping between the pool and the pump. The resultant value can be added to the reading on the pressure gauge (multiplied by 2.31 to get the reading in feet of head on the pressure side between the pump and the pool), to get a good estimate of the total dynamic head (TDH). For example, if the suction reading is 16″ of mercury (×1.13=18.08′) and the pressure reading is 22.5 psi (×2.31=51.97′) then the TDH of the existing system is approximately 70.05′. If the TDH of the new system is projected to be about 40.00′, then there will be a reduction in head loss of about 30′, which allows the pump to be run for an amount of time each day that is about 40% less than is necessary for the existing system. In order to get a true estimate of energy savings, it would be necessary to know the distance to the pool, the number of fittings, and other information, which cannot always be readily obtained as part of that information is buried underground. The technician can gather any other necessary information, such as distance to the pool or area information, as well as any necessary customer information 408. All this information can be entered via the data entry device, such as by typing the information into a form in a word processing program or spreadsheet, selecting checkboxes or radio buttons in a computer window, or any other ways known for entering data into a data processing or storage device 410. A certain amount of intelligence can be built into the forms to guide the field technician through the measurement collection and entry process. In one embodiment, other than typing in the customer information, all measurement and equipment data can be entered using a single selection action, such as a click of a mouse or stylus. The field technician can submit this information from the remote unit to a base unit located off-site, such as at a headquarters or central office location 410. This submission can be accomplished via any technological approach known for sending information, such as through any of a number of wireless data transfer mechanisms. The information and images can be sent together, or separately. For example, if the images are taken with a camera phone but the data is entered into a laptop, the technician can have the option of uploading the images to the laptop then submitting the images through a wireless modem of the laptop, or can choose to submit the images directly from the camera phone. The technician can contact personnel at the base unit 412, before, during, or after submission of the information. The technician can inform the personnel that the information has been gathered, allowing persons reviewing the information at the base unit to ask questions about the existing installation. These questions can include interpretations of included information or requests for further information. In an alternative embodiment, the information is sent as a message to the base unit. Once the message is received, a person monitoring the base unit can contact the technician after reviewing the information. The timing and number of contacts can vary as necessary. The contacts can be audio, video, text, or any other appropriate ways for communicating between the person at the base unit and the technician. The technician can provide any additional information over the phone, for example, or can enter the additional information via the data entry device of the remote unit and submit the information electronically. FIG. 5 shows steps of an exemplary process 500 by which personnel monitoring the base unit can receive information from a field technician and use this information to design a virtual system for the installation. As discussed above, a communication device of the base unit can receive a series of images of the installation, including images of the equipment, the pool, and the surrounding area, as well as customer and/or measurement information gathered by the technician 502. The information can be received by an operator of the base unit, who then can transfer the information to a designer (such as where a person is doing the design work by hand), or the information can be received directly by the designer. For simplicity of explanation, it will be assumed that the information is received by a designer. The information in one embodiment is imported into a spreadsheet program, which includes a number of formulas, as well as preset electricity costs and other selectable options. The spreadsheet can be tied to a central database that includes parameter values where appropriate, such as material costs, and that can be used to store the information for each job, design, and/or quotation. In another embodiment, the information is imported directly into a customized design program that automatically generates the design and uses information stored in a central database to compute values such as design costs and energy savings. The automatic design generation and cost computations can be done at the base unit or at the remote unit. If done at the remote unit, the design and values can be transmitted to the base unit for approval. Once the information is received from the field technician, and the designer has had an opportunity to review the images and information, the designer can contact the field technician to request further information 504, such as additional dimensions or clarification of existing numbers. The designer also can contact the field technician during the design process, where additional questions may arise. The communication from the designer can come via any appropriate mechanism, such as a cell phone call or text message. The designer can enter the additional information into the base unit 506 in order to ensure that the information is saved for later use. Once the designer has received all (or at least a minimum amount of) the necessary information, the designer can generate a sample equipment pad based on the information and images 508. The designer can determine the appropriate equipment (such as a pump of appropriate size) to be installed and connected in the sample pad. The sample pad can be a three-dimensional design created through a computer graphics program or virtual design studio using computer-generated parts, for example, or can be a physical model created using fittings and piping to create a physical structure. Methods for making virtual models using computer design programs are known in the art and will not be discussed herein in detail. If the design is done by computer, then any appropriate computer assisted drafting program can be used that is capable of generating a three-dimensional design allowing for precise measurements of dimensions to be made. If a physical model is made, fixed fittings and piping and/or variable fittings and piping can be used to create the model. By fixed fittings and piping, it is meant that the designer can have available a large number of fittings and pipe runs of different angles and sizes, such that these pieces can simply be connected appropriately to create the design. By variable fittings and piping, it is meant that the shape and/or size of each component can be altered, such as by bending a flexible run of pipe, in order to arrive at the final design. Using flexible components can be more accurate for the final design, as customized fittings and pipe runs can be made in order to maximize flow and minimize material cost. Using flexible fittings also allows for a more accurate material cost estimate where customized piping is to be used. The entire redesign process can take less than an hour, such as 10-15 minutes for a basic system and 40-60 minutes for a more complex system. Once the design is completed, the designer (or another appropriate person or device) can determine the approximate cost to implement the design 510, using factors such as types and numbers of fittings and amount of material takeoff. A series of pull-down bid templates can be provided to provide for fast and simple quotations. For a physical design, this can include taking actual measurements of the piping runs. For computer assisted designs, the calculations of lengths, widths, etc., can be done automatically through software, such that the total cost can be obtained at the end of the design process or can be updated continually throughout the design. The calculations also can determine the approximate cost savings, such as by factoring in the approximate improvement in flow and the reduction in power usage by a new pump. In order to estimate energy savings, a number of formulas can be used, such as: Kilowatts per hour consumed=Amps×Voltage×10% power loss factor/1000 This result can be used to determine the annual energy consumption by estimating the total number of hours of operation per year. For example, in a pool with a main filter pump and a cleaner/booster pump, the energy consumption for a 9.1 Amp/240V main pump, considering a 10% power loss factor, uses about 1.966 kW/hour. If this pump is run for 8 hours a day at $0.20 per kW/hour, then the annual cost to run the main pump will be about $1,148.04. For a 5.2 Amp/240V booster pump run 3 hours a day, the annual cost is about $245.96, for a total annual energy cost of about $1,394 to run both pumps. For a proposed replacement system, using a single 1.9 Amp/240V main pump, running 8 hours a day, the annual energy cost is about $239.69. By improving the flow through piping, such that this lower power pump can be used, the customer then can expect a projected annual energy savings of about $1,154.30, or about an 83% savings. Once the flow of the system is measured, the increase in flow (as a function of percent) can be used to reduce the amount of necessary run time of the pump to obtain the same throughput. For instance, if the flow is increased by 15% then the pump can run 15% less than is currently necessary. As discussed above, there is no easy way to know the exact underground piping configuration, such that total dynamic head often must be estimated. Certain suppositions about the piping can be used, such as average parameter values for runs of distance, such as average flow over a distance using standard PVC plumbing. In one embodiment, retrofits are estimated to obtain on average a 70% improvement in electrical costs, using both redirected flow and a new pump, with an overall range of about 25%-85% in energy savings. A virtual view of the completed design also can be created 512, such as by adding skins to virtual components and adding the actual images as a background, or by opening at least one of the images in a photo editing program and using piping templates to form a view of the approximate design. The designer also can shoot a physical design against a background such as a green screen (as known in the art) and drop the design onto one of the images. Many other approaches for creating a virtual view in a digital image are known, and ways for implementing each of these will not be discussed herein in detail. A view of the completed design, as well as pricing information and estimated cost savings, can be sent to the field technician 514, such as by using any of the devices discussed above for transmitting info between the base unit and remote unit. FIG. 6 shows steps of an exemplary process 600 by which the field technician can use the information received back from the base unit. As discussed above, a communication device of the remote unit can receive the virtual design, as well as information about the pricing for the project and the projected energy savings 602. This information can be shared with the potential customer during the same visit, as opposed to a subsequent visit as in previous systems. The field technician can have the opportunity to contact the designer or other base unit personnel with questions or comments before presenting the results to the customer 604. The technician can show the design to the customer 606, such as by bringing up the design on a display such as a laptop or PDA screen. Alternatively, the technician can use a projector to project images on a wall or other surface, or can print out a version to show the customer. The technician also can relay the pricing and cost information 608 using similar display devices, and can have the option of printing out forms such as a pricing form, cost savings form, plan layout, estimate, and/or contract. Once the potential customer has a chance to review the information 610, the customer can have the opportunity to request changes or ask additional questions 612, which can be transmitted to the base unit if necessary, with a response transmitted back to the remote unit for the technician to relay to the customer. After reviewing the proposal and asking any questions or making any changes, the customer can have the option of approving the work at a later time, or can choose to authorize the retrofit/design work during the visit by the field technician 614. There are any of a number of ways for the customer to authorize the work, such as by signing a contract and handing the field technician a check, or having the technician call the base unit or type information into the remote unit to provide a credit card number. In another embodiment, the remote device can include, or be connected to, a payment device such as a credit/debit card reader than can allow the customer to pay for the transaction immediately. This can include a deposit or full payment, depending upon factors such as the work being done and any applicable contractor limitations. Once the work is authorized and payment (or at least a deposit) is received, a kit can be created that includes all the necessary parts to retrofit the equipment pad. This kit can include, for example, all the fittings and piping, whether standard or customized, as well as any connecting hardware, a new pump, and any other necessary equipment. Alternative kits can minimally include only any customized piping and/or fittings. The kit can allow the installer to arrive at the location bringing only a standard tool set. The kit can be delivered to the installer, or can be delivered to the customer's address. When the installer arrives, the installer can remove any unnecessary equipment before the retrofit. The kit can come with a set of step by step instructions, and/or a series of diagrams, showing the installer how to install the new equipment and piping. The instructions in one embodiment are generated automatically by the design software. The instructions also can come with a parts list or any other information typically enclosed with a kit to be assembled. The parts of the kit also can be individually labeled for ease of assembly, and can be labeled or configured such that each part can only be installed in the correct orientation. The ability for the installer to simply connect the components can significantly reduce the install time, and therefore the installation cost, as well as reducing the likelihood for errors in the installation process. Further, a simplified installation process allows a less experienced installer to do the retrofit work, such that labor costs can be further reduced. Experienced people instead can be used to monitor the base unit and/or do the design work. Where an installer of an existing system would have to execute tasks such as measuring pipes, cutting pipes of the appropriate length and fitting pipes using existing components, and ensuring proper flow for the given system, an approach in accordance with various embodiments of the present invention allows an installer to simply remove the old equipment and piping, install the new pump, and attach the customized piping simply by screwing or otherwise connecting the new piping to the existing fittings and equipment. The entire process now can take on the order of four hours or less, much of which is involved in removing the existing equipment. Although described with respect to pool systems, there are a number of other industries that can utilize such a two-way communication design process to improve accuracy and reduce the amount of time necessary for the field technician and the customer in order to arrive at a design. While improved flow designs can be used for applications such as irrigation design, water flow, air flow, and power plants, any retrofit that has to design around existing two- or three-dimensional limitations can benefit from such an approach. Even designs of new installations can benefit by such an approach, where images and dimensions of the location for the design can be sent along with other necessary information in order to obtain a design and quote during a single customer visit. As discussed above, much of this functionality can be obtained through software at either the remote unit or base unit. This functionality can be stored in code form on any computer readable medium known or used in the art, such as but not limited to internal memory, external memory, hard disks, optical discs, magnetic discs, CD-ROMS, DVD-ROMS, memory sticks, and memory cards. The functionality also can be in code form in any of a number of signals transmitted to or from the units. The base unit and remote units can include any appropriate device capable of sending, receiving, and processing data. The functionality of the base unit can be contained in the remote unit in some embodiments, such that no communication is necessary unless circumstances dictate otherwise. It should be recognized that a number of variations of the above-identified embodiments will be obvious to one of ordinary skill in the art in view of the foregoing description. Accordingly, the invention is not to be limited by those specific embodiments and methods of the present invention shown and described herein. Rather, the scope of the invention is to be defined by the following claims and their equivalents.
|
G
|
G06
|
G06F
|
19
|
00
|
|||
11955517
|
US20090153341A1-20090618
|
Motion activated user interface for mobile communications device
|
ACCEPTED
|
20090604
|
20090618
|
[]
|
G08B2100
|
["G08B2100"]
|
8203528
|
20071213
|
20120619
|
345
|
156000
|
99476.0
|
ABDULSELAM
|
ABBAS
|
[{"inventor_name_last": "SPALINK", "inventor_name_first": "Karin", "inventor_city": "Durham", "inventor_state": "NC", "inventor_country": "US"}]
|
Disclosed is a system for interpreting motion of a mobile communications device as input to the mobile communications device. The system includes a processor for executing the various software components, a display, a microphone, a speaker, storage means for storing one or more motions and associated actions, a motion detecting device, and a sensing and interpretation application. The sensing and interpretation application detects motion of the mobile communications device via the motion detecting device. It then determines the current mode of the mobile communications device and compares the detected motion against a database of motions. Each stored motion is associated with a mode and an action to be performed by the mobile communications device. Upon finding a match between the detected motion and a motion in the storage means, the action associated with the detected motion and the current mode of the mobile communications device is performed.
|
1. A method of interpreting motion of a mobile communications device as input to the mobile communications device, the method comprising: detecting a specific type of motion with respect to the mobile communications device; determining a current mode of the mobile communications device; comparing the detected motion against a stored database of motions wherein each stored motion is associated with a mode of the mobile communications device and an action to be performed by the mobile communications device; and upon finding a match, within tolerable limits, between the detected motion and a motion in the stored database of motions, performing the action associated with the detected motion and the current mode of the mobile communications device. 2. The method of claim 1 further comprising training the mobile communications device to recognize a specific motion wherein said training comprises: selecting a mode to be associated with a specific motion; selecting an action to be performed within the selected mode; detecting a motion of the mobile communications device wherein the motion is user defined; associating the detected motion with the selected mode and the selected action; and storing the associated detected motion with the selected mode and the selected action in the stored database of motions. 3. The method of claim 1 wherein the current mode of the mobile communications device includes one of a phone mode, a picture mode, a music mode, a game mode, camera mode, a contacts mode, a settings mode, and a null mode. 4. The method of claim 3 wherein the null mode acts as a superseding mode such that any motions and actions associated within the null mode supersede motions and actions in other modes. 5. The method of claim 4 wherein an action includes one of a command or instruction that can be issued by an application within the mobile communications device, an audible output based on a recorded audio file, an audible output based on a text-to-speech conversion, a visual output, and a mechanical output. 6. The method of claim 1 wherein motion is detected using an accelerometer within the mobile communications device. 7. A computer readable medium storing a computer program product for interpreting motion of a mobile communications device as input to the mobile communications device, the computer readable medium comprising: computer program code for detecting a specific type of motion with respect to the mobile communications device; computer program code for determining a current mode of the mobile communications device; computer program code for comparing the detected motion against a stored database of motions wherein each stored motion is associated with a mode of the mobile communications device and an action to be performed by the mobile communications device, wherein the mode includes one of a phone mode, a picture mode, a music mode, a game mode, camera mode, a contacts mode, a settings mode, and a null mode, and wherein an action includes one of a command or instruction that can be issued by an application within the mobile communications device, an audible output based on a recorded audio file, an audible output based on a text-to-speech conversion, a visual output, and a mechanical output; and upon finding a match, within tolerable limits, between the detected motion and a motion in the stored database of motions, computer program code for performing the action associated with the detected motion and the current mode of the mobile communications device. 8. The computer readable medium of claim 7 further comprising computer program code for training the mobile communications device to recognize a specific motion wherein said computer program code for training comprises: computer program code for selecting a mode to be associated with a specific motion; computer program code for selecting an action to be performed within the selected mode wherein an action includes one of a an audible output based on a recorded audio file, an audible output based on a text-to-speech conversion, a visual output, and a mechanical output; computer program code for detecting a motion of the mobile communications device wherein the motion is user defined; computer program code for associating the detected motion with the selected mode and the selected action; and computer program code for storing the associated detected motion with the selected mode and the selected action in the stored database of motions. 9. The computer readable medium of claim 8 wherein the null mode acts as a superseding mode such that any motions and actions associated within the null mode supersede motions and actions in other modes. 10. The computer readable medium of claim 7 wherein motion is detected using an accelerometer within the mobile communications device. 11. A system for interpreting motion of a mobile communications device as input to the mobile communications device, the system comprising: a processor for executing the various software components of the mobile communications device; a display coupled with the processor; a microphone coupled with the processor for recording audio; a speaker coupled with the processor for outputting audio; storage means coupled with the processor for storing one or more motions and associated actions; a motion detecting device coupled with the processor; and a sensing and interpretation application coupled with the processor for: detecting a specific type of motion with respect to the mobile communications device via the motion detecting device; determining a current mode of the mobile communications device; comparing the detected motion against a database of motions in the storage means wherein each stored motion is associated with a mode of the mobile communications device and an action to be performed by the mobile communications device; and upon finding a match, within tolerable limits, between the detected motion and a motion in the storage means, performing the action associated with the detected motion and the current mode of the mobile communications device. 12. The system of claim 11 wherein the sensing and interpretation application can train the mobile communications device to recognize a specific motion by: selecting a mode to be associated with a specific motion; selecting an action to be performed within the selected mode; detecting a motion of the mobile communications device via the motion detecting device wherein the motion is user defined; associating the detected motion with the selected mode and the selected action; and storing the associated detected motion with the selected mode and the selected action in the storage means. 13. The system of claim 11 further comprising a text-to-speech engine coupled with the processor for converting text strings that can be associated with an action to audible output that can be output by the speaker. 14. The system of claim 11 wherein the mode of the mobile communications device includes one of a phone mode, a picture mode, a music mode, a game mode, camera mode, a contacts mode, a settings mode, and a null mode. 15. The system of claim 14 wherein the null mode acts as a superseding mode such that any motions and actions associated within the null mode supersede motions and actions in other modes. 16. The system of claim 15 wherein an action includes one of a command or instruction that can be issued by an application within the mobile communications device, an audible output based on recorded audio file that can be output by the speaker, an audible output based on a text-to-speech conversion that can be output by the speaker, a visual output that can be displayed by the mobile communications device display, a visual output that can be displayed by other lights visible on the mobile communications device, and a mechanical output. 17. The system of claim 11 wherein motion detecting device is an accelerometer.
|
<SOH> SUMMARY <EOH>Disclosed is a method and system for interpreting motion of a mobile communications device as input to the mobile communications device. The system includes a processor for executing the various software components of the mobile communications device, a display coupled with the processor, a microphone coupled with the processor for recording audio, a speaker coupled with the processor for outputting audio, storage means coupled with the processor for storing one or more motions and associated actions, a motion detecting device such as, for instance, an accelerometer coupled with the processor, ad a sensing and interpretation application coupled with the processor. The sensing and interpretation application detects a specific type of motion with respect to the mobile communications device via the motion detecting device. It then determines the current mode of the mobile communications device and compares the detected motion against a database of motions in the storage means. Each stored motion is associated with a mode of the mobile communications device and an action to be performed by the mobile communications device. Upon finding a match, within tolerable limits, between the detected motion and a motion in the storage means, the action associated with the detected motion and the current mode of the mobile communications device is performed. The sensing and interpretation application can also train the mobile communications device to recognize a specific motion. It does this by selecting a mode to be associated with a specific motion and selecting an action to be performed within the selected mode. Next, the sensing and interpretation application detects a user defined motion of the mobile communications device via the motion detecting device. The detected motion is then associated with the selected mode and the selected action and stored away. The system and method can also utilize a text-to-speech engine to convert text strings that can be associated with an action to audible output that can be output by the speaker. The mode of the mobile communications device can include, among others, one of a phone mode, a picture mode, a music mode, a game mode, camera mode, a contacts mode, a settings mode, and a null mode. The null mode acts as a superseding mode such that any motions and actions associated within the null mode supersede motions and actions in other modes.
|
SUMMARY Disclosed is a method and system for interpreting motion of a mobile communications device as input to the mobile communications device. The system includes a processor for executing the various software components of the mobile communications device, a display coupled with the processor, a microphone coupled with the processor for recording audio, a speaker coupled with the processor for outputting audio, storage means coupled with the processor for storing one or more motions and associated actions, a motion detecting device such as, for instance, an accelerometer coupled with the processor, ad a sensing and interpretation application coupled with the processor. The sensing and interpretation application detects a specific type of motion with respect to the mobile communications device via the motion detecting device. It then determines the current mode of the mobile communications device and compares the detected motion against a database of motions in the storage means. Each stored motion is associated with a mode of the mobile communications device and an action to be performed by the mobile communications device. Upon finding a match, within tolerable limits, between the detected motion and a motion in the storage means, the action associated with the detected motion and the current mode of the mobile communications device is performed. The sensing and interpretation application can also train the mobile communications device to recognize a specific motion. It does this by selecting a mode to be associated with a specific motion and selecting an action to be performed within the selected mode. Next, the sensing and interpretation application detects a user defined motion of the mobile communications device via the motion detecting device. The detected motion is then associated with the selected mode and the selected action and stored away. The system and method can also utilize a text-to-speech engine to convert text strings that can be associated with an action to audible output that can be output by the speaker. The mode of the mobile communications device can include, among others, one of a phone mode, a picture mode, a music mode, a game mode, camera mode, a contacts mode, a settings mode, and a null mode. The null mode acts as a superseding mode such that any motions and actions associated within the null mode supersede motions and actions in other modes. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an illustration of some of the internal components of a mobile communications device. FIG. 2 is a sample screen shot describing aspects of embodiments according to the present invention. FIG. 3 is a flow chart or logic diagram describing motion training aspects of embodiments according to the present invention. FIG. 4 is a flow chart or logic diagram describing motion editing aspects of embodiments according to the present invention. FIG. 5 is a flow chart or logic diagram describing motion deleting aspects of embodiments according to the present invention. FIG. 6 is a flow chart or logic diagram describing operational aspects of embodiments according to the present invention. FIG. 7 illustrates a flip-type of motion that can be defined and recognized by embodiments according to the present invention. FIG. 8 illustrates a shaking motion that can be defined and recognized by embodiments according to the present invention. FIG. 9 illustrates a spinning motion that can be defined and recognized by embodiments according to the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is an illustration of some of the internal components of a mobile communications device 10. Within the mobile communications device 10 there are included several components that operate to practice the embodiments of the invention. Not all the components that comprise a mobile communications device 10 are illustrated, however. A processor 20 serves to coordinate and control the operations and interactions among the various components. Among the various components, there is shown a motion sensing and interpretation application 30, other mobile communications device applications 40 (e.g., voice recognition, contacts, games, etc.), internal (and/or removable) storage 50, motion sensing devices 60, a text-to-speech engine 70, a microphone 80, and a speaker 90. The motion sensing and interpretation application 30 includes the software and software interfaces for managing sensed motion and the responses thereto. The motion sensing and interpretation application 30 further includes training responses to be associated with specified motions. Other mobile communications device applications 40 generally include the other applications of the mobile communications device that can be influenced by or operated on by the motion sensing and interpretation application 30. For instance, the application that answers the phone can be altered to accept sensed motion as a means for answering and disconnecting a phone call. In another example, an application for displaying pictures can be made to display the next picture of a series (e.g., slideshow) using a shaking motion such as a flick of one's wrist. There are numerous other examples involving other mobile communications device applications 40 that can be integrated to accept motion as a source of input. The internal (and/or removable) storage 50 serves to store data associated with the motion sensing and interpretation application 30 such as, for instance, a library of stored motions that are linked with mobile communications device modes and operations/tasks. The motion sensing devices 60 can include at least one or more accelerometer devices used to detect motion of the mobile communications device. The text-to-speech engine 70 can be included to convert text data to verbal output. Text data can be associated with a sensed motion and converted to speech upon recognition of the motion. The converted speech can then be output via speaker 90. The microphone 80 can be used to record words or phrases that can be associated with sensed motion and output via speaker 90 when the associated motion is sensed and identified. For instance, if the mobile communications device were to be dropped and hit the floor, it could output the word “ouch!” upon or just after impact if the motion sensed was defined and indicative of a dropped mobile communications device. FIG. 2 is a sample screen shot describing aspects of embodiments according to the present invention. In this illustration, the mobile communications device 10 is displaying 95 three of the functions (motion training, editing, and deleting) available to the motion sensing and interpretation application 30. A user can scroll and select from among the list shown 95. FIG. 3 is a flow chart or logic diagram describing motion training aspects of embodiments according to the present invention. One of the functions of the motion sensing and interpretation application 30 is to learn motions and associate them with actions or outputs. This can sometimes be referred to as a training function. Motion training begins 300 when is shown the several modes 305 of the mobile communications device. Modes can include, but are not limited to, phone mode, camera mode (if the mobile communications device has an integrated camera), music mode (if the mobile communications device has an integrated music player, game mode, picture mode, contacts mode, settings mode, and a null mode, etc. The null mode can include more irreverent actions such as “phone drop” or “phone toss”. While the mobile communications device is in a particular mode, sensed motion will have a meaning specific to that mode. This allows for the same sensed motion to be used in different modes. However, if an action is defined for a null mode the action will be performed when the specified motion is detected regardless of the current mode. Thus, actions associated with the null mode should not be associated with any other mode as null mode acts as a superseding mode with respect to detected motion. Examples of motions for the null mode include dropping the mobile communications device and tossing the mobile communications device into the air. Examples of actions associated with dropping the mobile communications device or tossing the mobile communications device in the air include an audible “ouch” or an audible “wheeee” respectively. Once the mobile communications device processes a user's mode selection 310, a list of outputs/actions is generated for that mode 315. Phone mode, for instance, can include outputs/actions such as “answer”, “hang up”, “mute”, “volume up/down”, “call waiting answer”, etc. Other modes will have outputs/actions that apply to their mode. A user will select an output/action 320. The mobile communications device will then prompt the user to create a motion that is to be associated with the mode action/output pairing 325. The mobile communications device then processes the motion supplied by the user in response to the prompt 330. The motion is then associated with the mode action/output pairing 335 and stored in a database of motion definitions 340. The user is prompted whether to train another motion 345. If the response is “no” training ends 350. Otherwise, control is returned to process 305 and the user is shown the list of modes. It is also anticipated that several motions may have pre-defined or canned mode and output/action associations stored in memory. If so, these can be edited by the user if desired according to the procedures set out below. FIG. 4 is a flow chart or logic diagram describing motion editing aspects of embodiments according to the present invention. The user may also edit an existing mode/motion pairing by selecting from a displayed list of modes for the mobile communications device 410. The mobile communications device will process the selection 420 and display a list of outputs/actions for the selected mode 430 obtained from the database of defined motions. The user selects from the list and the mobile communications device will process the selection of the action/output 440 by allowing the user to change 450 the output/action for the selected motion. FIG. 5 is a flow chart or logic diagram describing motion deleting aspects of embodiments according to the present invention. The user may also delete an existing mode/motion pairing by selecting from a displayed list of modes for the mobile communications device 510. The mobile communications device will process the selection 520 and display a list of outputs/actions for the selected mode 530 obtained from the database of defined motions. The user selects from the list and the mobile communications device will process the selection of the action/output by deleting the output/action for the selected motion 540. FIG. 6 is a flow chart or logic diagram describing operational aspects of embodiments according to the present invention. When the motion sensing and interpretation application 30 is active, motion is continuously being sensed 610 and interpreted 620 based on the current mode of the mobile communications device. When motion for a mode is sensed that has a defined output/action stored 340, the mobile communications device will cause the defined output/action to occur 630. Upon completion of the output/action, the motion sensing and interpretation application 30 returns to its vigilant state where it processes subsequent motion searching for matches based on mode and motion. The types of actions and/or outputs that can be associated with detected motion can include, but are not limited to, audible output via the speaker, visual output via the display, mechanical output such as vibration, and launching an application and/or performing a command within an application. Audible output can be based on pre-recorded sounds, words, phrases as well as links to other audio files such as music files. Audible output can also include text-to-speech conversions of text data. Visual output can include, but is not limited to, graphical imagery on the display such as color and design bursts and links to image files that can be displayed. Visual output can also include events not associated with the display such as flashing the lights associated with the keys of the keypad as well as any other lights visible on the mobile communications device that are not associated with the display. To help illustrate the scope of the present invention, several illustrative embodiment examples are presented that indicate some, but not all of, the capabilities of the present invention. FIG. 7 illustrates a flip-type of motion that can be defined and recognized by embodiments according to the present invention. In this example, an mobile communications device is shown in five consecutive states (a)-(e) to indicate a flip-type motion. In state (a) the mobile communications device is shown face forward. In state (b) the mobile communications device is shown rotated (or flipped) 90° such that it is in a profile mode. In state (c) the mobile communications device is shown face down having been rotated another 90°. In state (d) the mobile communications device is shown rotated (or flipped) another 90° such that it is in a second opposite profile mode. Lastly, in state (e) the mobile communications device is shown rotated (or flipped) 90° again such that it is returned to face front. This sequence or progression can be associated with an output/action for one or more modes. Moreover, the motion can be broken down into 90° intervals such that each quarter turn can have its own associated mode/motion definition. FIG. 8 illustrates a shaking motion that can be defined and recognized by embodiments according to the present invention. The arrows between the mobile communications device's in this illustration indicate a back and forth motion between state (a) and state (b). This back and forth motion can be termed “shaking” and can be associated with an output/action for one or more modes. FIG. 9 illustrates a spinning motion that can be defined and recognized by embodiments according to the present invention. In this example, the mobile communications device starts out oriented face front with a standard top/bottom orientation. As it is rotated (spun), the mobile communications device's orientation is continuously changing as it traverses an arc and eventually comes full circle. The speed of the rotation can be varied. The motion sensing and interpretation application 30 can be used for functional and personalization applications. Functional applications include using motion as a user input device to answer the phone, for instance. Personalization applications can include having the phone make quirky sounds or change display characteristics based on sensed motions. For instance, if the user drops his phone it can be made to say “Ouch!” upon or just after impact while the display can be made to show an explosion of some sort. While FIGS. 7-9 have described types of motion that can be defined and used in the embodiments of the present invention, it is important to note that the embodiments of the present invention are not limited to just these motions. They are merely exemplary to help describe aspects of the present invention. For instance, motions can be detected and interpreted in two and three dimensions. Moreover, motion such as knocking the mobile communications device against a hard surface can be detected and interpreted similar to knocking one's hand on a door. Thus, there are numerous types of motion that can be detected and interpreted by the embodiments of the present invention and the examples described herein are not intended to be limiting. An example of a game or game mode application could be the game of Roulette. Roulette is a casino game in which a large numbered and colored slotted disk is spun around while a small metal ball bounces around the disk until the disk comes to rest and the ball rests within one of the numbered/colored slots. The object of the game is to guess the number and/or color of the slot in which the ball will come to rest. The mobile communications device can be made to simulate the game by spinning the mobile communications device on a table top. The spinning motion, in this particular mode, will cause a bouncing ball sound and rapid click sound indicative of the sounds made in Roulette. As the spinning begins to ebb, the sounds will do the same. Once the motion stops, the final action/output is to have the mobile communications device randomly select one of the Roulette numbers and its associated color. The selection can be displayed by the mobile communications device using the color as a background for the number. In picture mode, the mobile communications device can use detected motion to perform various functions. For instance, if the user shakes the mobile communications device once it could indicate “display the next picture”. Two shakes could indicate “zoom in”. Flipping the mobile communications device over to its back could indicate “exit picture mode”. Another example of personalization could be a phone toss. The motion associated with an mobile communications device hurtling through the air can be detected and associated with a pre-recorded audio output such as “Wheeeeee”. If the mobile communications device includes a text-to-speech engine, written data can be converted to audible output and associated with a specific motion. For instance, suppose the motion detected is indicative of a sudden or violent change. The mobile communications device can be programmed with a text question such as “Are you alright?” If the mobile communications device further contains a voice recognition (VR) engine and software, it can process the user's response if it is simple enough. If the user responds “No.”, the mobile communications device can interpret and then ask, “Should I dial 9-1-1?” If the user responds, “Yes” the mobile communications device can initiate the emergency phone call. The foregoing are a small sampling of the types of motion and the associated responses thereto that can be implemented for these and other examples under the various embodiments of the present invention. As will be appreciated by one of skill in the art, the present invention may be embodied as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product on a computer-usable storage medium having computer-usable program code embodied in the medium. Any suitable computer readable medium may be utilized. The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a transmission media such as those supporting the Internet or an intranet, or a magnetic storage device. Note that the computer-usable or computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. Computer program code for carrying out operations of the present invention may be written in an object oriented programming language such as Java, Smalltalk, C++ or the like. However, the computer program code for carrying out operations of the present invention may also be written in conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). The present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. Any prompts associated with the present invention may be presented and responded to via a graphical user interface (GUI) presented on the display of the mobile communications device or the like. Prompts may also be audible, vibrating, etc. The flowcharts and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art appreciate that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown and that the invention has other applications in other environments. This application is intended to cover any adaptations or variations of the present invention. The following claims are in no way intended to limit the scope of the invention to the specific embodiments described herein.
|
G
|
G08
|
G08B
|
21
|
00
|
||||
11785880
|
US20070187825A1-20070816
|
Electronic component, semiconductor device, methods of manufacturing the same, circuit board, and electronic instrument
|
ACCEPTED
|
20070801
|
20070816
|
[]
|
H01L2348
|
["H01L2348"]
|
7307351
|
20070420
|
20071211
|
257
|
784000
|
79459.0
|
MANDALA
|
VICTOR
|
[{"inventor_name_last": "Hashimoto", "inventor_name_first": "Nobuaki", "inventor_city": "Suwa-shi", "inventor_state": "", "inventor_country": "JP"}]
|
The present invention is a semiconductor device capable of relieving thermal stress without breaking wire. It comprises a semiconductor chip (12), a solder ball (20) for external connection, wiring (18) for electrically connecting the semiconductor chip (12) and the solder ball (20), a stress relieving layer (16) provided on the semiconductor chip (12), and a stress transmission portion (22) for transmitting stress from the solder ball (20) to the stress relieving layer (16) in a peripheral position of an electrical connection portion (24a) of the solder ball (20) and wiring (18).
|
1. An electronic component, comprising: a semiconductor chip; an electrode disposed on the semiconductor chip; a wiring electrically connected to the electrode, the wiring disposed on the semiconductor chip; a first resin layer formed over the semiconductor chip and the wiring, the first resin layer having an opening on a first portion of the wiring; and an external terminal provided above the first portion of the wiring, the external terminal electrically connected to the wiring via the opening, wherein a second portion of the wiring between the electrode and the external terminal extends in a direction that changes in a horizontal plane on the semiconductor chip, wherein the wiring extends from the first portion of the wiring in a direction perpendicular to a direction of stress generated by differences in a coefficient of thermal expansion between a mounting board and the electronic component when the electronic component is bonded to the mounting board.
|
<SOH> BACKGROUND ART <EOH>To pursue high density mounting in semiconductor devices, bare chip mounting is the ideal. However, quality control and handling of bare chips are difficult. For this reason, CSP (chip size/scale package) technology, in which the package size is close to the chip size, has been developed. In such a CSP semiconductor device, an important problem is to relieve the thermal stress due to the differences in coefficient of thermal expansion between the semiconductor chip and the mounting board. In particular, as the number of pins continues to increase, it is essential that no wiring breaks are caused by thermal stress, since wiring is required to connect from the electrodes to the solder balls. The present invention addresses the above described problems, and has as its object the provision of an electronic component, a semiconductor device, methods of manufacturing these, a circuit board on which these are mounted, and an electronic instrument having this circuit board.
|
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 shows a first embodiment of the semiconductor device. FIG. 2 shows a second embodiment of the semiconductor device. FIG. 3 shows a third embodiment of the semiconductor device. FIGS. 4A and 4B shows a fourth embodiment of the semiconductor device. FIG. 5 shows a fifth embodiment of the semiconductor device. FIG. 6 shows a sixth embodiment of the semiconductor device. FIG. 7 shows a seventh embodiment of the semiconductor device. FIG. 8 shows an eighth embodiment of the semiconductor device. FIG. 9 shows a ninth embodiment of the semiconductor device. FIG. 10 shows a tenth embodiment of the semiconductor device. FIGS. 11A and 11B show an eleventh embodiment of the semiconductor device. FIGS. 12A and 12B show a twelfth embodiment of the semiconductor device. FIG. 13 shows a thirteenth embodiment of the semiconductor device. FIG. 14 shows a fourteenth embodiment of the semiconductor device. FIG. 15 shows a fifteenth embodiment of the semiconductor device. FIG. 16 shows a sixteenth embodiment of the semiconductor device. FIGS. 17A to 17 E show a process of fabricating the semiconductor device of the present invention. FIGS. 18A to 18 C show a process of fabricating the semiconductor device of the present invention. FIG. 19 shows a CSP semiconductor device. FIG. 20 shows a circuit board mounted with a semiconductor device fabricated by application of the method of the present invention. FIG. 21 snows an electronic instrument equipped with a circuit board mounted with a semiconductor device fabricated by application of the method of the present invention. detailed-description description="Detailed Description" end="lead"?
|
This is a Continuation of application Ser. No. 10/331,510 filed Dec. 31, 2002, which is a Continuation of application Ser. No. 09/953,858 filed Sep. 18, 2001, which is a Continuation of application Ser. No. 09/142,856 filed Mar. 26, 1999 which is a National Stage of PCT/JP98/00130 filed Jan. 16, 1998. TECHNICAL FIELD The present invention relates to a compact electronic component and a semiconductor device whose final formed package size is close to the size of the chip (semiconductor element), to methods of manufacturing these, to a circuit board on which these are mounted, and to an electronic instrument having this circuit board. BACKGROUND ART To pursue high density mounting in semiconductor devices, bare chip mounting is the ideal. However, quality control and handling of bare chips are difficult. For this reason, CSP (chip size/scale package) technology, in which the package size is close to the chip size, has been developed. In such a CSP semiconductor device, an important problem is to relieve the thermal stress due to the differences in coefficient of thermal expansion between the semiconductor chip and the mounting board. In particular, as the number of pins continues to increase, it is essential that no wiring breaks are caused by thermal stress, since wiring is required to connect from the electrodes to the solder balls. The present invention addresses the above described problems, and has as its object the provision of an electronic component, a semiconductor device, methods of manufacturing these, a circuit board on which these are mounted, and an electronic instrument having this circuit board. DISCLOSURE OF THE INVENTION The semiconductor device of the present invention comprises a semiconductor element, an external electrode provided within the region of the semiconductor element for external connection, wiring connected through a connection portion to the external electrode and electrically connecting the semiconductor element and the external electrode, a stress relieving portion provided on the semiconductor element, and a stress transmission portion transmitting stress from the external electrode to the stress relieving portion. Since the semiconductor element and external electrode of the present invention are connected by the wiring, the pitch of external electrode can be converted as required. The stress transmission portion transmits stress from the external electrode to the stress relieving portion, and stress can be thus relieved. The wiring is connected to the external electrode through a connection portion. The connection portion is not restricted to the case of existing as a separate member between the wiring and the external electrode, but includes the case of being a part of at least one of the wiring and external electrode. The connection portion is not restricted to directly contacting at least one of the wiring and external electrode, but includes the case of not directly contacting either. That is to say, the connection portion of the present invention indicates at least a part of the member electrically connecting the wiring and external electrode. More specifically, the wiring may be provided on the stress relieving portion, and the stress transmission portion may be provided in the connection portion. By this means, since the wiring is provided on the stress relieving portion, the connection portion and stress transmission portion are provided on the stress relieving portion, and the stress from the external electrode is transmitted to the stress relieving portion. Alternatively, the wiring may be provided under the stress relieving portion, the connection portion may be provided to pass through the stress relieving portion, and the stress transmission portion may be formed on the stress relieving portion integrally with the connection portion. By this means, since the connection portion passes through the stress relieving portion, the connection portion does not transmit stress vertically to the stress relieving portion. In place of this, the stress transmission portion provided on the stress relieving portion transmits stress to the stress relieving portion. The stress relieving portion may be formed with a thickness to reach the stress transmission portion from the wiring. The stress relieving portion may have a groove formed outside of the stress transmission portion. By forming a groove, the stress relieving portion is more easily deformed, and stress from the stress transmission portion can be absorbed more easily. The stress relieving portion may have a space formed between a contact position on the wiring and a contact position under the stress transmission portion. By this means, the stress relieving portion is more easily able to, deform, and stress from the stress transmission portion can be absorbed more easily. A stress relieving portion having such a space may be formed with a thickness to reach the stress transmission portion from the wiring, and then may be etched from the outside of the stress transmission portion to underneath thereof. The present invention may further comprise a supplementary transmission portion provided at least between a root periphery of the external electrode and the stress relieving portion, and transmitting stress from the external electrode to the stress relieving portion. By means of the supplementary transmission portion, stress from the external electrode is transmitted to the stress relieving portion, and a concentration of stress between the external electrode and the stress transmission portion can be prevented. The supplementary transmission portion may be formed of a material capable of being used for the stress relieving portion. The stress relieving portion may include a first stress relieving layer and a second stress relieving layer formed on the first stress relieving layer; the wiring may be provided between the first and second stress relieving layers; the connection portion may be provided to penetrate the second stress relieving layer; and the stress transmission portion may be formed on the second stress relieving layer integrally with the connection portion. By this means, the connection Portion transmits stress in the vertical direction to the first stress relieving layer. Meanwhile, the stress transmission portion transmits stress to the second stress relieving layer. In this way, stress is relieved at two locations. The stress relieving portion may include a first stress relieving layer and a second stress relieving layer formed on the first stress relieving layer; the wiring may be provided between the first and second stress relieving layers; the connection portion may be provided to penetrate the second stress relieving layer; and the stress transmission portion may include a first transmission portion formed between the first and second stress relieving layers integrally with the connection portion, and a second transmission portion formed on the second stress relieving layer integrally with the connection portion. The connection portion transmits stress in the vertical direction to the first stress relieving layer. Stress is also transmitted to the first stress relieving layer from the first transmission portion of the stress transmission portion. Furthermore, the stress transmission portion has a second stress transmission portion, and this second stress transmission portion transmits stress to the second stress relieving layer. In this way, stress is relieved at three locations. It is preferable that the second transmission Portion has a larger area than the first transmission portion, and transmits the stress to the second stress relieving layer. Since the second transmission portion transmits a large amount of stress, the stress transmitted by the first transmission portion is comparatively small. The first transmission portion is close to the direct contact portion of the connection portion and wiring. Therefore, by reducing the stress transmitted from the first transmission portion, the effect on this contact portion can be reduced. It is preferable that the stress transmission portion is provided without contacting the connection portion. By this means, the stress transmission portion does not transfer stress to the direct contact portion of the connection portion and wiring. The stress relieving portion may have an isolation portion for inhibiting transmission of the stress between a support region supporting the stress transmission portion and a connection region in which the connection portion is formed. Because the isolation portion is provided, stress transmitted from the stress transmission portion to the support region of the stress relieving portion is not transmitted to the connection region. Therefore, transfer of stress from the stress transmission portion through the stress relieving portion to the connection portion also does not occur. Here, the isolation portion may for example be a groove. The wiring preferably has a bent portion forming an empty portion with the semiconductor element. By this means, since the wiring can freely deform in the bent portion, maximum stress absorption is possible. A gel material may be injected in the empty portion to protect the bent portion. The stress relieving portion may include a first stress relieving layer and a second stress relieving layer formed on the first stress relieving layer; the wiring may include a first wiring portion formed below the first stress relieving layer and a second wiring portion formed between the first and second stress relieving layers; the connection portion may include a first wiring connection portion penetrating the first stress relieving is layer and connecting the first and second wiring portions and a second wiring connection portion penetrating the second stress relieving layer and connecting the external electrode and the second wiring portion; the first and second wiring connection portions may be disposed on different planes; and the stress transmission portion may include a first transmission portion formed between the first and second stress relieving layers integrally with the first wiring connection portion, and a second transmission portion formed on the second stress relieving layer integrally with the second wiring connection portion. Since the first and second wiring connection portions of the present invention are provided with first and second transmission portions respectively, in each of the wiring connection portions, stress can be transmitted to the stress relieving layer. The contact position of the first wiring connection portion with respect to the first and second wiring portions, and the contact position of the second wiring connection portion with respect to the external electrode and second wiring portion are disposed on different planes. Therefore, stress applied to one of the contact positions is not directly easily transferred to the other contact position. Since stress transferred from the external electrode is relieved before reaching the semiconductor element, the effect on this semiconductor element can be reduced. The wiring may be brought out from the external electrode substantially at right angles to a direction of generation of the stress. By this means, the generating direction of the stress and the extending direction of the wiring are substantially orthogonal. Thus the application of tension to the wiring in the direction of its extension and consequent wiring breaks can be prevented. The stress transmission portion may be formed at a position outside of the connection portion. Since the stress transmission portion is transmitting stress at a peripheral position of the connection portion of the external electrode and wiring, stress can be transmitted over a large area. The electronic component of the present invention comprises an electronic element; an external electrode for external connection; wiring electrically connecting the electronic element and the external electrode; a stress reliving portion provided on the electronic element; and a stress transmission portion transmitting stress from the external electrode to the stress relieving portion, at a peripheral Position of an electrical connection portion of the external electrode and the wiring. The method of manufacturing an electronic component of the present invention comprises: a step of integrally forming in substrate form a plurality of electronic element; a step of forming an electrode on the electronic element in substrate form; a step of providing a stress relieving portion on the electronic element in substrate form, avoiding the electrode; a step of forming wiring from the electrode; a step of providing a stress transmission portion transmitting stress from the external electrode to the stress relieving portion, in a peripheral position of the electrical connection portion of the wiring and external electrode; and a step of separating the electronic element in substrate form into individual elements. The method of manufacturing a semiconductor device of the present invention comprises; a step of forming an electrode on a wafer; a step of providing a stress relieving portion on the wafer avoiding the electrode; a stop of forming wiring from the electrode; a step of providing a stress transmission portion transmitting stress from the external electrode to the stress relieving portion, in a peripheral position of the electrical connection portion of the wiring and external electrode; and a step of separating the wafer into individual elements. With an aspect of the present invention, after a stress relieving layer, wiring, and external electrode are formed on the wafer, the wafer is cut up to obtain individual semiconductor devices. Therefore, since the formation of stress relieving layer, wiring, and external electrode can be carried out simultaneously for a large number of semiconductor devices, the fabrication process can be simplified. The step of forming a stress relieving portion may be carried out after the step of forming wiring; and a step of forming a groove by etching in the stress relieving portion outside of the stress transmission portion may be performed before the step of separating the wafer. By forming the groove, the stress relieving portion is more easily deformed, and stress from the stress transmission portion can be absorbed more easily. The step of forming the stress relieving portion may be carried out after the step of forming wiring; and a step of etching the stress relieving portion to under the stress transmission portion may be performed before the step of separating the wafer. By this means, the stress relieving portion has a space formed between a contact position over the wiring and a contact position under the stress transmission portion. Thus, the stress relieving portion is more easily deformed, and stress from the stress transmission portion can be absorbed more easily. A step of providing a material capable of being used for the stress receiving portion from over the stress relieving portion to at least a root periphery of the external electrode, to form a Supplementary transmission portion, may be performed before the step of separating the wafer. In this way, when the supplementary transmission portion is formed, stress from the external electrode is transmitted to the stress relieving portion by means of the supplementary transmission portion, and a concentration of stress between the external electrode and the stress transmission portion can be prevented. The circuit board of present invention has the above described semiconductor device and a substrate on which a desired wiring pattern is formed; and external electrodes of the semiconductor device are connected to the wiring pattern. The electronic instrument of the present invention has this circuit board. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a first embodiment of the semiconductor device. FIG. 2 shows a second embodiment of the semiconductor device. FIG. 3 shows a third embodiment of the semiconductor device. FIGS. 4A and 4B shows a fourth embodiment of the semiconductor device. FIG. 5 shows a fifth embodiment of the semiconductor device. FIG. 6 shows a sixth embodiment of the semiconductor device. FIG. 7 shows a seventh embodiment of the semiconductor device. FIG. 8 shows an eighth embodiment of the semiconductor device. FIG. 9 shows a ninth embodiment of the semiconductor device. FIG. 10 shows a tenth embodiment of the semiconductor device. FIGS. 11A and 11B show an eleventh embodiment of the semiconductor device. FIGS. 12A and 12B show a twelfth embodiment of the semiconductor device. FIG. 13 shows a thirteenth embodiment of the semiconductor device. FIG. 14 shows a fourteenth embodiment of the semiconductor device. FIG. 15 shows a fifteenth embodiment of the semiconductor device. FIG. 16 shows a sixteenth embodiment of the semiconductor device. FIGS. 17A to 17E show a process of fabricating the semiconductor device of the present invention. FIGS. 18A to 18C show a process of fabricating the semiconductor device of the present invention. FIG. 19 shows a CSP semiconductor device. FIG. 20 shows a circuit board mounted with a semiconductor device fabricated by application of the method of the present invention. FIG. 21 snows an electronic instrument equipped with a circuit board mounted with a semiconductor device fabricated by application of the method of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention is now described with reference to the drawings. The present invention can be applied to a compact electronic component, in particular the examples described are of application to a semiconductor device. Some of the drawings are enlarged for clarity. In particular the following explanation is in terms of a final separated individual semiconductor device, and therefore the terminology used, forms, and so forth, may be slightly different from in actual practice. Where a semiconductor chip is referred to, this may refer not only to a single separated device (that is, a chip) but also to devices in the form of a wafer. In other words, the term “semiconductor chip” used here refers to a certain circuit formed on a base substrate (for example of silicon) and capable of being used once separated, and is not restricted in respect of whether separated or whether still integral. Furthermore, references are restricted to typical locations where explanation is required such as wiring, and therefore in the figures where other locations are similar, or other constructions, are omitted. First Embodiment FIG. 1 is a sectional view showing a first embodiment of the semiconductor device. A semiconductor device 10 shown in this figure comprises a stress relieving layer 16 and wiring 18 formed thereon In more detail, on a semiconductor chip 12, a stress relieving layer 16 is formed to avoid an electrode 14, and wiring 18 is formed from the electrode 14 over the stress relieving layer 16. The stress relieving layer 16 is formed from a photosensitive polyimide resin, and when the semiconductor device 10 is mounted on a substrate (not shown in the drawings), relieves the stress created by the difference in the coefficient of thermal expansion between the semiconductor chip 12 and the substrate. The polyimide resin is insulating with respect to the wiring 18, is able to protect the surface a and has heat resistance when a solder ball. 20 is melted. A polyimide resin with a low Young's modulus (such as an olefin polyimide resin or BCB manufactured by the Dow Chemical Corporation) is preferably used, and in particular it is preferable that the Young's modulus be not more than about 20 kg/mm2. The stress relieving layer 16 has a larger stress relieving effect the thicker it is, but a thickness approximately in the range 1 to 100 μm is preferable. However, when a polyimide resin with a Young's modulus of approximately 10 kg/mm2 is used, a thickness of approximately 10 μm will be sufficient. Alternatively, a material which has a low Young's modulus and is effective for stress relieving such as, silicone denatured polyimide resin, epoxy resin, or silicone denatured epoxy resin may be used as the stress relieving layer 16. When a nonphotosensitive resin is used, in combination with another resist, a required pattern may be formed by a photo-etching process. The wiring 18 is formed of chromium (Cr). Here, chromium (Cr) is selected because of its good adhesion properties to the polyimide resin forming the stress relieving layer 16. Alternatively, when resistance to cracks is considered, ductile metal such as aluminum, aluminum alloys such as aluminum-silicon and aluminum-copper, copper alloys, copper, or gold may be used. Besides, when titanium or titanium-tungsten, having excellent resistance to moisture is selected, wiring breaks due to corrosion can be prevented. Titanium is also preferable as it has favorable adhesion properties with respect to polyimide. When titanium is used for the wiring 18, a multi-layer construction of titanium and another of the above metals may be used. The wiring 18 is formed in a film by sputtering, plating, a combination thereof, or another method, and is patterned by photoetching. It should be noted that the above described examples of materials for the stress relieving layer and wiring may equally be applied in a suitable way to all of the second and subsequent embodiments in the same way as to the first embodiment. On the wiring 18, a solder ball (external electrode) 20 is provided. In more detail, a stress transmission portion 22 is provided on the wiring 18, a base 24 is provided on this stress transmission portion 22, and a solder ball 20 is provided on the seat 24. The stress transmission portion 22 and base 24 are formed by copper plating, and the solder ball is formed of solder of at least a hemispherical ball shape. It should be noted that the stress transmission portion 22 and base 24 are preferably formed from the same metal as that Used for the material of the wiring 18. A characteristic of the present embodiment is that as shown in FIG. 1, the width d of the base portion 24a of the base 24 on the stress transmission portion 22 and the width D of the stress transmission portion 22 satisfy the relation d<D. In other words, the base portion 24a of the base 24 forms a part (connection portion) of the element electrically connecting the solder ball (external electrode) 20 and the wiring 18, and the stress transmission portion 22 extends integrally to the peripheral position thereof. By forming such a stress transmission portion 22, the solder ball 20 is supported on the stress relieving layer 16 with a is comparatively wide width D. Such the wide stress transmission portion 22 is effective for transmitting stress. That is to say, for example, when heat is applied to the substrate and the semiconductor device mounted on the substrate because of the difference in the coefficient of thermal expansion between the mounting board and the semiconductor chip 12, a stress of bending the semiconductor chip 12 is created. This stress is a force bending over, with the center of the solder ball 20 as-axis. According to the present embodiment, by means of the stress transmission portion 22 with the comparatively wide width D, the solder ball 20 is supported with respect to the stress relieving layer 16. Therefore, the stress tending to bend over the solder ball 20 is transmitted over a wide area to the stress relieving layer 16, and the stress can be largely absorbed by the stress relieving layer 16. Besides, with regard to the stress transmission effect, the second and subsequent embodiments are also similar to that shown in the first embodiment. It should be noted that while omitted from the drawings, to prevent corrosion and the like of the wiring a wiring protection layer such as solder resist is preferably provided as the outermost layer. Second Embodiment FIG. 2 is a sectional view showing a second embodiment of the semiconductor device. The semiconductor device 30 shown in this figure has wiring 38 formed beneath a stress relieving layer 36. In more-detail, on a semiconductor chip 32, with an oxide layer (not shown in the drawings) acting as an insulating layer interposed, wiring 38 is formed from an electrode 34. A stress relieving layer 36 is formed over this. It should be noted that the wiring 38 is formed of chromium (Cr). In the stress relieving layer 36, a hole 36a is formed by photolithography, so that in the region of this hole 36a the wiring 38 is not covered by the stress relieving layer 36. In other words, the hole 36a is formed so that the wiring 38 is positioned directly under the hole 36a. Then a chromium (Cr) layer 42 and a copper (Cu) layer 44 are formed by sputtering applied to the wiring 38 and the inner circumferential surface and opening rim surface forming the hole 36a. In other words, the chromium (Cr) layer 42 and copper (Cu) layer 44 are formed to pass through the stress relieving layer 36. Moreover, in the opening rim portion, the chromium (Cr) layer 42 and copper (Cu) layer 44 are arranged to extend with a comparatively wide width. On the copper (Cu) layer 44, a base 46 is formed of copper (Cu), and on this base 46, a solder ball 40 is formed. The solder ball 40 is electrically connected to the electrode 34 through the drawn out wiring 38, the copper (Cu) layer 44, the chromium (Cr) layer 42 and the base 46. According to the present embodiment, at the opening rim portion of the hole 36a, stress from the solder ball 40 is transmitted from a stress transmission portion 48 formed from at least a part of the chromium (Cr) layer 42, copper (Cu) layer 44 and base 46 to the stress relieving layer 36. This stress transmission portion 48 is positioned outside a connection portion 38a. The connection portion 38a is a part of the chromium (Cr) layer 42, and is a part of the member electrically connecting the solder ball (external electrode) 40 and wiring 38. In this example, the stress transmission portion 48 is provided to include a flange portion 48a, in other words, a projecting portion. Therefore, the stress acting to bend over with the center of the solder ball 40 as axis can be transmitted over a wide area to the stress relieving layer 36 by the stress transmission portion 48. The larger the area of the stress transmission portion 48, the more effective it is. Besides, according to the present embodiment, since the stress transmission portion 48 Is disposed at a different height from the connection portion 38a with respect to the wiring 38, and the connection portion 38a and wiring 38 are disposed on a hard oxide layer, the stress generated is absorbed by the stress relieving layer 36. Therefore, stress is less likely to be transmitted to the connection portion 38a, and to the wiring 38, and as a result cracks can be prevented. Third Embodiment FIG. 3 is a sectional view showing a third embodiment of the semiconductor device. The semiconductor device 31 shown in this figure has a supplementary transmission layer 33 formed on the stress relieving layer 36 of the semiconductor device 30 shown in FIG. 2. In the present embodiment also, the connection portion 38a is a part of the chromium (Cr) layer 42, and is a part of the member electrically connecting the solder ball (external electrode) 40 and wiring 38. The supplementary transmission layer 33 is formed in contact with, at least, the root periphery of the solder ball 40. Therefore, through the supplementary transmission layer 33, stress is transmitted from the solder ball 40 to the stress relieving layer 36. By this means, the stress is dispersed, and between the solder ball 40 and the stress transmission portion 48, in particular at the connecting portion of the base 46 with the copper (Cu) layer 44, a concentration of stress is avoided. It should be noted that here, the stress transmission portion 48 is formed from at least a part of the chromium (Cr) layer 42, copper (Cu) layer 44 and base 46. The supplementary transmission layer 33 is constructed of a resin capable of being used for the stress relieving layer 36, and its thickness is determined by the flexibility (Young's modulus) of the resin itself, and the magnitude of the stress which it is required to be transmitted. More specifically, when a soft resin is used, a large stress transmission is possible by forming the supplementary transmission layer 33 with greater thickness. Besides, when a comparatively hard resin is used, by forming the supplementary transmission layer 33 to be thin, excessive stress transmission can be avoided. The supplementary transmission layer 33 can be formed by spin coating after formation of the solder ball 40. Alternatively, after formation of the stress transmission portion 48 (including the base 46), and before forming the solder ball 40, a resin layer may be formed on the stress relieving layer 36, an opening formed in the resin layer on the stress transmission portion 48, and the solder ball 40 provided. In this case, the opening can be formed by the application of a photolithography technique, or an etching technique (dry or wet). These methods are suitable when the supplementary transmission layer 33 is formed before cutting the semiconductor device into individual pieces. Fourth Embodiment FIGS. 4A and 4B are sectional views showing a fourth embodiment of the semiconductor device. It should be noted that FIG. 4A is a section along the line IV-IV in FIG. 4B. The semiconductor device 37 shown in these figures has grooves 35 formed in the stress relieving layer 36 of the semiconductor device 30 shown in FIG. 2. However, FIGS. 2 and 4A differ in the section position. In the present embodiment again, the connection portion 38a is a part of the member electrically connecting the solder ball (external electrode) 40 and wiring 38 (see FIG. 2). As shown in FIGS. 4A and 4B, the grooves 35 are formed positioned on the outside of the stress transmission portion 48 in the stress relieving layer 36. By this means, when stress is transmitted from the stress transmission portion 48 to the stress relieving layer 36, the stress relieving layer 36 can more easily deform at a portion closer to the stress transmission portion 48 than the grooves 35. By means of this, the stress relieving layer 36 can more easily absorb stress. In particular, by forming the grooves 35 when the material forming the stress absorption layer 36 has a low degree of flexibility (high Young's modulus), a stress relieving ability equal to that of the case of a material of a high degree of flexibility (low Young's modulus) can be obtained. If a material of a high degree of flexibility is used, and then the above described forming is carried out, stress relief can be even more so achieved. The same effect can be expected in the fifth and sixth embodiments described below. Besides, the grooves 35 are formed on the sides in the direction (shown by an arrow in FIG. 4B) in which stress is applied from the stress transmission portion 48 to the stress relieving layer 36. Therefore, in the direction in which the stress is applied, the stress relieving ability is increased. It should be noted that the position of formation of the grooves 35 is not restricted to the positions shown in FIGS. 4A and 4B. For example, the grooves 35 may be formed on sides in a direction other than the direction (shown by an arrow in FIG. 4B) in which stress is applied from the stress transmission portion 48 to the stress relieving layer 36, or may be formed to surround the stress transmission portion 48. Fifth Embodiment FIG. 5 is a sectional view showing a fifth embodiment of the semiconductor device. The semiconductor device 39 shown in this figure is one in which the stress relieving layer 36 of the semiconductor device 30 shown in FIG. 2 is etched. That is to say, the stress relieving layer 41 of the semiconductor device 39 is formed to be thinner than the stress relieving layer 36 shown in FIG. 2. A space 43 is formed between the contact position below the flange 48a of the stress transmission portion 48 and the contact position on the wiring 38. In other words, below the flange portion 48a of the stress transmission portion 48, the stress relieving layer 41 forms a neck. This neck portion may have a circular cross-section, or may equally be formed with a taper. In the present embodiment too, the connection portion 38a is part of the member electrically connecting the solder ball (external electrode) 40 and wiring 38. In this way, by forming the space 43 below the flange portion 481 of the stress transmission portion 48, the stress relieving layer 41 is more easily able to deform. By means of this, the stress relieving layer 41 is more easily able to absorb stress. The space 43, can be formed by carrying out isotropic dry etching on the stress relieving layer 36 shown in FIG. 2. More specifically, by isotropic dry etching, the etch rate is approximately equal in the horizontal direction and the depth direction. As a result, as shown in FIG. 5, it is possible to etch into a necked shape below the flange portion 48a of the stress transmission portion 48. By means of this, the space 43 can be formed. Sixth Embodiment FIG. 6 is a sectional view showing a sixth embodiment of the semiconductor device. The semiconductor device 45 shown in this figure has a supplementary transmission portion 47 added to the semiconductor device 39 shown in FIG. 5. That is to say, in FIG. 6, a supplementary transmission portion 47 is formed continuous with the stress relieving layer 41 on the periphery of the solder ball 40. The supplementary transmission portion 47 is interposed at least between the root periphery of the solder ball 40 and the stress relieving layer 41. By this means, stress applied to the solder ball 40 can be transmitted through the supplementary transmission portion 47 to the stress relieving layer 41. Moreover, the stress is dispersed, and concentration of the stress at the connecting area of the solder ball 40 and stress transmission portion 48 is avoided. The semiconductor device 45 having a supplementary transmission portion 47 of this type can be fabricated by, forming the stress relieving layer 36 and supplementary transmission layer 33, as shown in FIG. 3, and then carrying out etching in the same way as in the fifth embodiment. In the present embodiment too, the connection portion 38a is part of the member electrically connecting the solder ball (external electrode) 40 and wiring 38. Seventh Embodiment FIG. 7 is a sectional view showing a seventh embodiment of the semiconductor device. This seventh embodiment has the characteristics of both the first and second embodiments. In this figure, a semiconductor device 50 has wiring 58 formed between first and second stress relieving layers 56 and 57. In more detail, on a semiconductor chip 52, a first stress relieving layer 56 is formed to avoid an electrode 54, and wiring 58 is formed from the electrode 54 over the stress relieving layer 56. This structure is the same as in the first embodiment. Over the wiring 58, a second stress relieving layer 57 is formed. The second stress relieving layer 57 may also be provided with a thickness in a range similar to that of the above described first stress relieving layer 56. In this stress relieving layer 57, a hole 57a is formed. A chromium (Cr) layer 62 and a copper (Cu) layer 64 are formed to pass through the stress relieving layer 57. Alternatively, in place of these, the wiring 18 described in the first embodiment may be used. At opening rim portion of the hole 57a, and the chromium (Cr) layer 62 and copper (Cu) layer 64 are arranged to broaden with comparatively wide range. On the copper (Cu) layer 64 a base 66 is formed, and a solder ball 60 is formed on this base 66. In the opening rim Portion of the hole 57a, stress from the solder ball 60 is transmitted from a stress transmission portion 68 formed by the chromium (Cr) layer 62, copper (Cu) layer 64, and a part of base 66, to the second stress relieving layer 57. The stress transmission portion 68 is provided outside the connection portion 58a. Here, the connection portion 58a is part of the chromium (Cr) layer 62, and is part of the member electrically connecting the solder ball (external electrode) 60 and wiring 58. The structure above the wiring 58 is the same as in the second embodiment, and detailed description is omitted. According to the present embodiment, stress in the vertical direction from the solder ball 60 is transmitted through the connection portion 58a to the first stress relieving layer 56 and absorbed, while being transmitted through the stress transmission portion 68 to the second stress relieving layer 57 and absorbed. In this way, a two-stage absorbing structure is provided, whereby the stress absorption is even more effective. It should be noted that in the present embodiment, the second stress relieving layer 57 also serves as a protecting layer for the wiring 58 and semiconductor chip 52. It should be noted that the second stress relieving layer 57 of the present embodiment may also have the grooves 35, the necked form of the stress relieving layer 41, or the supplementary transmission portion 47 of the fourth to sixth embodiments. Eighth Embodiment FIG. 8 is a sectional view showing an eighth embodiment of the semiconductor device. The semiconductor device 51 shown in this figure has a supplementary transmission layer 53 formed on the first stress relieving layer 57 of the semiconductor device 50 shown in FIG. 7. In the present embodiment too, the connection portion 58a is part of the member electrically connecting the solder ball (external electrode) 60 and the wiring 58. The supplementary transmission layer 53 is formed at least contacting the root periphery of the solder ball 60. Therefore, through the supplementary transmission layer 53, stress is transmitted from the solder ball 60 to the stress relieving layer 57. By this means, stress is dispersed, and a concentration of stress at the connecting portion of the solder ball 60 and the stress transmission portion 68 is avoided. It should be noted that the material and method of formation of the supplementary transmission layer 53 is the same as in the third embodiment, and description is omitted. Ninth Embodiment FIG. 9 is a sectional view showing a ninth embodiment of the semiconductor device. The ninth embodiment is a modification of the seventh embodiment. In this figure, a semiconductor device 70 has wiring 78 formed between first and second stress relieving layers 76 and 77. In more detail, a first stress relieving layer 76 is formed on the semiconductor chip 72, avoiding an electrode 74. Wiring 78 is formed from the electrode 74 over the stress relieving layer 76. On the wiring 78, a second stress relieving layer 77 is formed. To pass through this stress relieving layer 77, a copper (Cu) layer 82 is formed by sputtering, a copper (Cu) layer 84 is formed by plating, a copper (Cu) layer 86 is formed by sputtering, and a base 88 is formed by plating. A solder ball 80 is formed an this base 88. Here, the copper (Cu) layer 82 and copper (Cu) layer 84 have a larger area than the base 88 and base portion 88a of the copper (Cu) layer 86. In the copper (Cu) layer 82 and copper (Cu) layer 84, a stress transmission portion 89 corresponding to the position of the periphery of the base portion 88a transmits stress from the solder ball 80 to the first stress relieving layer 76. It should be noted that a portion of the stress transmission portion 89 (the portion contacting the base portion 88a) forms a part (connection portion) of the member electrically connecting the solder ball (external electrode) 80 and wiring 78. According to the present embodiment, since the stress transmission portion 89 is formed positioned on the periphery of the base portion 88a electrically connecting the solder ball 80 and wiring 78, stress can be transmitted to the first stress relieving layer 76 over a large area. It should be noted that in the present embodiment, even if the first stress relieving layer 76 is omitted, the stress can be absorbed by the second stress relieving layer 77. In the present embodiment too, a stress transmission portion 87 similar to the stress transmission portion 68 of the seventh embodiment (see FIG. 7) may be further formed, and a similar effect will be obtained. Tenth Embodiment FIG. 10 is a sectional view showing a tenth embodiment of the semiconductor device. This tenth embodiment is a modification of the ninth embodiment. Here, to describe only difference from the ninth embodiment. A copper (Cu) layer 92 and copper (Cu) layer 93 formed on wiring 91 are smaller than a stress transmission portion 94. Therefore, stress tending to bend over a solder ball 95 is transmitted from the stress transmission portion 94, but hard to be transmitted from the copper (Cu) layer 92 and copper (Cu) layer 93. Moreover, the copper (Cu) layer 92 and copper (Cu) layer 93 do not function as a stress transmission portion, and therefore stress tends not to be transmitted to wiring 91. By this means, breaks of the wiring 91 can be prevented. In the present embodiment, a part of the stress transmission portion 94 forms a part (connection portion) of the member electrically connecting the solder ball (external electrode) 9S and wiring 91. It should be noted that the effect in the ninth embodiment that even if the first stress relieving layer 76 is omitted, the stress can be absorbed by the second stress relieving layer 77 is the same in the tenth embodiment. Eleventh Embodiment FIGS. 11A and 11B show an eleventh embodiment of the semiconductor device. It should be noted that FIG. 11B is a plan view seen along line XI-XI in FIG. 11A. AS shown in these figures, with a semiconductor device 100, a solder ball 114 is supported by a stress transmission portion 112 in a position not contacting an electrical connection portion 110. In more detail, on an oxide layer 104 formed on a semiconductor chip 102, wiring 106 is formed. The wiring 106 electrically connects a pad 106a positioned in the center of the solder ball with to an electrode 108. Moreover, the wiring 106 extends from the pad 106a in a direction perpendicular to the direction (shown by an arrow in FIG. 11B) of stress generated by differences in the coefficient of thermal expansion between the mounting board and the semiconductor device 100. Therefore, even if stress is applied to the wiring 106, since force is not applied in the direction of extension in the vicinity of the pad 106a, wiring breaks are less likely to occur. On the wiring 106 a stress relieving layer 118 is formed. However, on the pad 106a a hole is formed in the stress relieving layer 118, and the connection portion 110 is formed to electrically connect the pad 106a and solder ball 114. The connection portion 110 forms a part of the member electrically connecting the solder ball (external electrode) 114 and wiring 106. Besides, in a peripheral position of the connection portion 110 and in a noncontact position, between an oxide layer 104 and solder ball 114 a plurality of stress transmission portions 112 are provided. For this reason, in the stress relieving layer 118 a plurality of holes are formed. It should be noted that the connection portion 110 and stress transmission portion 112 are form,ed continuously as projections projecting downward from a base 116 which supports the solder ball 114. The present embodiment has the above described structure, and its effect is now described. In the present embodiment, the solder ball 114 is electrically connected to the wiring 106 by the connection portion 110 in a central position thereof. Then a stress transmission portion 112 is provided in a peripheral position of the connection portion 110 and in a noncontact position. Therefore, since it is in the noncontact state, the influence of the stress transmitted by the stress transmission portion 112 tends not to be transmitted to the connection portion 110. Thus, stress is not transmitted to the wiring 106 and wiring breaks can be prevented. The base 116 partially contacts above the stress relieving layer 118. In particular, a contact portion 116a positioned on the periphery of the stress transmission-portion 110 is such as to transmit stress to the stress relieving layer 118 and absorb the same. Twelfth Embodiment FIGS. 12A and 12B show a twelfth embodiment of the semiconductor device. It should be noted that FIG. 12B is a plan view seen along line XII-XII in FIG. 12A. This twelfth embodiment is a modification of the above described eleventh embodiment. Here the differences from the eleventh embodiment are described. In FIGS. 12A and 12B, a semiconductor device 120 has first and second stress relieving layers 122 and 124. Then wiring 126 is formed on the first stress relieving layer 122, and a stress transmission portion 128 is formed on the first stress relieving layer 124. Therefore, stress from a solder ball 130 is transmitted from the stress transmission portion 128 to the first stress relieving layer 122, and absorbed. It should be noted that with regard to a connection portion 132 formed on a pad 126a, the structure is the same as the connection portion 110 shown in FIG. 11A, and therefore description is omitted. That is to say, the connection portion 132 forms a part of the element electrically connecting the solder ball (external electrode) 130 and wiring 126. According to the present embodiment, stress is relieved through the stress transmission portion 128 by the first stress relieving layer 122. Therefore, the base 134 has a flange formed in a peripheral position of the stress transmission portion 128. The contact portion with the second stress relieving layer 124 is omitted. However, a contact portion may be provided in the same way as in the eleventh embodiment. Thirteenth Embodiment FIG. 13 shows a thirteenth embodiment of the semiconductor device. This thirteenth embodiment is a modification of the above described eleventh and twelfth embodiments. In other words, in place of the plurality of pillar-shaped stress transmission portions 112 shown In FIGS. 11A and 11B, the semiconductor device 140 shown in FIG. 13 has a cylindrical stress transmission portion 142. This stress transmission portion 142 has a part cut away to allow wiring 144 to be led to the inside, and is arranged not to contact the wiring 144. Even with a stress transmission portion 142 of this type, the same effect as in the eleventh embodiment can be achieved. The connection portion electrically connecting the solder ball (external electrode) and wiring is the same as in the twelfth embodiment. Fourteenth Embodiment FIG. 14 shows a fourteenth embodiment of the semiconductor device. The semiconductor device 150 shown in this figure also has a first stress relieving layer 154 formed on a semiconductor chip 152. However, in this stress relieving layer 154 a substantially circular groove 156 is formed. Thus an island portion 158 delineated by the groove 156 is formed. Besides, wiring 159 is formed to reach the island portion 158. In more detail, in order to form the wiring 159, the groove 156 is formed in a C-shape. On the first stress relieving layer 154, a second stress relieving layer 160 is formed. In the second stress relieving layer 160, a hole 160a is formed to extend further outside than the groove 156. Then on the inner surface and opening rim portion of the hole 160a, on the surface 154a of the first stress relieving layer 154 exposed by the hole 160a, and on the wiring 159 formed on the island portion 158, a base 162 is provided with a thin metal film interposed by sputtering. A solder ball 164 is provided on the base 162. According to the present embodiment, island portion 158 is isolated from the region receiving stress from the solder ball 164, by means of the groove 156. Therefore, stress tends not to be transmitted to the wiring 159, and the occurrence of wiring breaks can be prevented. It should be noted that the connection portion being one part of the member electrically connecting the solder ball (external electrode) and wiring is the same as in the twelfth embodiment. Fifteenth Embodiment FIG. 15 shows a fifteenth embodiment of the semiconductor device. The semiconductor device 170 shown in this figure has a bump 174 provided on a stress relieving layer 172 to absorb stress. It is the same as the above embodiments from the point of view of stress absorption. The characteristic of the present embodiment is that wiring 176 has a bent portion 180 forming an empty portion between the wiring 176 and the semiconductor chip 178, and the empty portion is injected with a gel material 182. It should be noted that since the gel material 182 is inserted for the purpose of reinforcement, it may be omitted. Besides, the wiring 176 is preferably formed of metal from the viewpoint of ductility. In this way, when the bent portion 180 is formed, even if stress is applied to the wiring 176, it is absorbed by the bent portion 180. Therefore, stress transmitted from the bump 174 is not transmitted to the electrode 184. In this way wiring breaks can be prevented. To form the bent portion 180 a resist is deposited to outline the bent portion 180, and the wiring 176 is formed thereon, then the resist is removed by dry etching or wet etching. It should be noted that a material other than resist can be used as long as it can be etched. While omitted from the drawings, a wiring protection layer being a solder resist or the like is preferably provided as the outermost layer to prevent corrosion and the like of the wiring. The present embodiment can be applied to other embodiments, and in this case the connection portion being one part of the member electrically connecting the solder ball (external electrode) and wiring is the same as in the twelfth embodiment. Sixteenth Embodiment FIG. 16 shows a sixteenth embodiment of the semiconductor device. The semiconductor device 190 shown in this figure has first wiring 194 formed on a semiconductor chip 192, a first stress relieving layer 196 formed on this wiring 194, and second wiring 198 formed on this stress relieving layer 196. In more detail, on the first wiring 194, a hole is formed in the first stress relieving layer 196, and the second wiring 198 is formed from the first wiring 194 over the first stress relieving layer 196. On the second wiring 198, a copper (Cu) layer 200 is formed by plating, and on this copper (Cu) layer 200, a second stress relieving layer 202 is formed. In the second stress relieving layer 202, a hole 202a is formed over the copper (Cu) layer 200. A bump 204 is provided on the copper (Cu) layer 200. Part of the bump 204 contacts the second stress relieving layer 202, and is arranged to transmit stress. According to the present embodiment, the connection portion 206 of the first and second wiring 194 and 198 and the connection portion 208 of the second wiring 198 and the bump 204 are disposed on the different planes. Here, the connection portion 206 indicates the portion of contact between the first and second wiring 194 and 198, and the connection portion 208 indicates the portion of contact between the second wiring 198 and the bump 204. The connection portions 206 and 208 form a part of the member electrically connecting the wiring 194 and bump (external electrode) 204. Therefore, even if stress is transmitted from the bump 204 through the connection portion 208 to the second wiring 198, this stress tends not to be transmitted to the other connection portion 206. In this way, since stress is made less likely to be transmitted to the first wiring 194, wiring breaks in this wiring 194 are prevented. (Fabrication Process) FIGS. 17A to ISC show a manufacturing method of a semiconductor device of the present embodiment. First, using well-known technology, normally, an electrode 302 and other elements are formed up to the state before carrying out dicing on a wafer 300 (see FIG. 17A). In the present embodiment, the electrode 302 is formed of aluminum, but equally an aluminum alloy material (for example, aluminum silicon, aluminum silicon copper, and so on) or a copper material may be used. On the surface of the wafer 300, a passivation film (not shown in the drawings) such as an oxide layer is formed to prevent chemical change. The passivation film is formed to avoid not only the electrode 302, but also a scribing line used to carry out dicing. By not forming the passivation film on the scribing line, during dicing the creation of debris from the passivation film can be avoided, and furthermore, the generation of cracks in the passivation film can be prevented. Next, sputtering is carried out with the wafer 300 as the target, and the foreign objects are removed from the surface of the wafer 300 (in other words, reverse sputtering). Then, as shown in FIG. 17A, by means of sputtering a titanium tungsten (TiW) layer 304 and copper (Cu) layer 306 are superimposed on the surface of the wafer 300. It should be noted that in this fabrication process, the example described has titanium tungsten (TiW) and copper (Cu) used for the wiring, but the present invention is not limited to this. Then, when the wiring resistance is lowered, in particular on the copper layer 306, a copper plating layer 308 is formed by electroplating. The layer thicknesses may be, for example, approximately the following values: Titanium tungsten layer: 1000 angstroms (10−10 m) Copper layer: 1000 angstroms (10−10 m) Copper plating layer: 0.5 to 5 μm Next, as shown in FIG. 17B, the titanium tungsten layer 304, copper layer 306, and copper plating layer 308 are dry etched, applying photolithography technology, to form wiring 310. In more detail, a photoresist (not shown in the drawings) is applied on the copper plating layer 308, and prebaking, exposure and development are carried out. Drying and postbaking are carried out after washing. Then dry etching is applied to the copper plating layer 308 and copper layer 306 for rinsing, and the titanium tungsten layer 304 is dry etched. Next, the photoresist is removed and washing carried out. In this way, as shown in FIG. 17B, the wiring 310 is formed. Next, the wiring 310 is subjected to ashing by an O2 plasma, then after water is removed from the wafer 300, as shown in FIG. 17C, a polyimide resin 312 is applied to the whole surface of the wafer 300. The polyimide resin 312 forms a stress relieving layer same as the stress relieving layer 36 and the like shown in FIG. 2. Here, by means of the ashing, the adhesion properties of the wiring 310 and wafer 300 with the polyimide resin 312 are improved. For the polyimide resin 312, it is preferable to use one with good adhesion properties with the passivation film of the wafer 300, a low Young's modulus and a low water absorption ratio, and for which a large film thickness is possible. The polyimide resin 312 is now subjected to prebaking, exposure, drying, development, washing, drying and curing processes. In this way, as shown in FIG. 17D, a hole 314 is formed in the polyimide resin 312. The polyimide resin 312, while adhered to the wiring 310 and wafer 300, is shrunk by the drying and curing processes, so that the inside of the hole 314 is shaped as a 60 to 70 degree taper. Therefore, it is preferable that the polyimide resin 312 is selected so that a taper is shaped inside the hole 314. Next, the surface of the polyimide resin 312 is subjected to ashing by an O2 plasma, and sputtering is carried out with this polyimide resin 312 as the target to remove foreign objects. By means of the ashing, the adhesion properties of the surface of the polyimide resin 312 with a metal film are improved. Then as shown in FIG. 17E, by sputtering applied to the whole surface of the polyimide resin 312, a titanium tungsten (TiW) layer 316 and copper (Cu) layer 318 are formed to be overlaid. Then, a copper plating layer 320 is formed on the copper layer 318 by electroplating. It should be noted that in place of the titanium tungsten layer 316, a titanium (Ti) layer may be formed. The layer thicknesses may be, for example, approximately the following values: Titanium tungsten layer: 1000 angstroms (10−10 m) Copper layer: 1000 angstroms (10−10 m) Copper plating layer: 0.5 to 100 μm Next, a photoresist is applied on the copper plating layer 320, then the copper plating layer 320 and copper layer 318 are etched after prebaking, exposure, development, washing, drying and postbaking are carried out. Then the titanium tungsten layer 316 is etched after washing, and the photoresist is removed, and washing is carried out. In this way, as shown in FIG. 18A, the stress transmission portion 322 is formed on the wiring 310. Then ashing is carried out to the stress transmission portion 322 by an O2 plasma. Then as shown in FIG. 18B, a solder paste 324 is disposed on the stress transmission portion 322. The solder paste 324 can be provided, for example, by screen printing. Besides, when the particle size of the solder paste 324 is of the range around 25 to 15 μm, the printing mask will be easily released. Alternatively, the solder paste 324 may be provided by a solder plating method. Next, through a reflow process, the solder paste 324 is melted to form a solder ball 326 by means of surface tension, as shown in FIG. 18C. Then the flux is subjected to washing. According to the above described manufacturing method of a semiconductor device, almost all steps are completed within the stage of wafer processing. In other words, the step in which the external terminals for connection to the mounting board are formed is carried out within the stage of wafer processing, and it is not necessary to carry out the conventional packaging process, that is to say, in which individual semiconductor chips are handled, and an inner lead bonding process and external terminal formation process are carried out for each individual semiconductor chip. Besides, when the stress relieving layer is formed, a substrate such as a patterned film is not required. For these reasons, a semiconductor device of low cost and high quality can be obtained. Other Embodiments The present invention can be applied to a CSP semiconductor device. In FIG. 19 is shown a typical CSP semiconductor device. In this figure, a semiconductor chip 1 has wiring 3 formed extending from electrodes 2 toward the center of an active surface 1a, and an external electrode 5 is provided on each wiring 3. All of the external electrodes 5 are provided on a stress relieving layer 7, so that the stresses can be relieved when mounted on a circuit board (not shown in the drawings). Besides, excluding the region of the external electrodes 5, a solder resist layer 8 is formed as a protective film. The stress relieving layer 7 is formed at least in the region surrounded by the electrodes 12. It should be noted that the electrodes 2 refer to the portions connected to the wiring 3. Besides, when the area required to form the external electrodes 5 is considered, although not shown in FIG. 19, the stress relieving layer 7 may be provided on the outside of the electrodes 2, and the wiring 3 brought around thereon, to provide the external electrodes 5 in the same way. The electrodes 2 are positioned around the periphery of the semiconductor chip 1, in an example of the so-called peripheral electrode type, however, equally an area array type of semiconductor chip in which the electrodes are formed in a region inside the periphery of the semiconductor chip may be used. In this case, the stress relieving layer 7 may be formed to avoid at least a portion of the electrodes 2. As shown in this drawing, the external electrodes 5 are provided not on the electrodes 2 of the semiconductor chip 1, but in the active region (the region in which the active elements are formed) of the semiconductor chip 1. By providing the stress relieving layer 7 in the active region, and further positioning (bringing In) the wiring 3 within the active region, the external electrodes 5 can be provided within the active region. That is to say, a pitch conversion can be carried out. As a result, when laying out the external electrodes 5, the interior of the active region, that is to say, a region of a particular plane can be provided. Thus the flexibility for positioning the external electrodes 5 is greatly increased. By bending the wiring 3 at the required position, the external electrodes 5 can be aligned in a lattice. It should be noted that this is not an essential construction of the present invention, and therefore the-external electrodes 5 do not necessarily have to be disposed in a lattice. In FIG. 19, at the junction of the electrodes 2 and wiring 3 the size of the electrodes 2 and the size of the wiring 3 are such that: wiring 3<electrodes 2 but it is preferable that: electrodes 2≦wiring 3 In particular, in the case that: electrodes 2<wiring 3 not only is the resistance of the wiring 3 reduced, but also, since the strength is increased, wiring breaks are prevented. In each of the above described embodiments, in cases where external stress applied to the solder ball is concentrated in the wiring, the wiring is designed to be curved (or bent) in the planar direction, and in addition to or separate from this, a bent (curved) structure as in the fifteenth embodiment is adopted to each embodiment, so that concentration of Stress on the wiring is dispersed. In such a semiconductor device, almost all steps can be completed within the stage of wafer processing. More specifically, a plurality of electrodes 2 are formed on the wafer, and a stress relieving layer 7 is disposed on the wafer avoiding the electrodes 2, and individual semiconductor devices are cut from the wafer after gone through the process of forming wiring 3 from the electrodes 2. Here, for the formation of the electrodes 2 and wiring 3, for example, sputtering, etching, or other thin metal film forming technology can be applied. For the formation of the external electrodes 5, a solder plating process can be applied. Furthermore, for the formation and processing of the stress relieving layer 7, a photolithography in which a photosensitive resin is exposed and developed can be applied. These steps can all be carried out during wafer processing. In this way, after carrying out almost all of the steps is in wafer processing, the individual semiconductor devices are cut. By doing this the stress relieving layer 7, wiring 3, and external electrodes 5 of a plurality of semiconductor devices can be formed simultaneously. As a result, the fabrication process can be simplified. In FIG. 20 is shown a circuit board 1000 on which is mounted a semiconductor device 1100 fabricated by the method of the above described embodiment. The circuit board generally uses an organic compound substrate such as glass epoxy. A wiring pattern of, for example, copper is formed on the circuit board to form a desired circuit. The electrical connection Is achieved by mechanical connection of the wiring pattern and the external terminals of the semiconductor device. In this case, since the above described semiconductor device has a construction for absorbing strain generated by differences in thermal expansion with the exterior provided by the stress relieving portion, when this semiconductor device is mounted on the circuit board and thereafter, the reliability can be improved. Besides, if appropriate attention is paid to the wiring of the semiconductor device., the reliability during connection and the reliability after connection can be improved. It should be noted that the mounting area can also be reduced to the area for mounting as a bare chip. Therefore, when this circuit board is used in an electronic instrument, the electronic instrument itself can be made more, compact. Besides, within the same area, greater effective mounting space can be made available, and it is possible to design for greater functionality. Next, as an electronic instrument provided with this circuit board 1000, FIG. 21 shows a notebook personal computer 1200. It should be noted that the above described embodiments apply the present invention to a semiconductor device, but the present invention can be applied to any surface-mounted electronic component, whether active or passive. Electronic components include, for example, resistors, capacitors, coils, oscillators, filters, temperature sensors, thermistors, varistors, variable resistors, and fuses. In addition, by using given electronic element in place of the semiconductor element in the above described embodiments, and by forming the same kind of stress transmission portion as in the above described embodiments, stress can be relieved by the stress relieving portion, and wiring breaks and the like can be prevented. Since the manufacturing method is the same as in the above described embodiment, description is omitted.
|
H
|
H01
|
H01L
|
23
|
48
|
|||
11656054
|
US20080176250A1-20080724
|
Method of testing for ATP load in commercial laundry and for data tracking the results
|
ACCEPTED
|
20080709
|
20080724
|
[]
|
G01N3336
|
["G01N3336", "G01N2176", "C12Q166"]
|
7628823
|
20070122
|
20091208
|
008
|
137000
|
97128.0
|
KHAN
|
AMINA
|
[{"inventor_name_last": "Banks", "inventor_name_first": "Allen G.", "inventor_city": "Franklin", "inventor_state": "OH", "inventor_country": "US"}]
|
A method of testing for sanitization of textiles comprises the steps of cleaning textiles in a water solution and testing the water solution for the presence of contaminants such as adenosine triphosphate (ATP), typically with a luminometer. Typically, the water solution will be drained from a cleaning vessel and tested. Another option is the testing of the water solution extracted after draining such as by a spin cycle. The method provides improved accuracy of test results as to the level of cleanliness. In addition, testing at this early step of the laundering process allows for additional cleaning if needed without having undertaken costly and time-consuming steps such as drying. Moreover, absent re-contamination of the textiles after the cleaning process, drying and finishing procedures may be accomplished without further sanitizing the textiles.
|
1. A method comprising the steps of: cleaning textiles with a water solution whereby the water solution becomes used; and testing the used water solution for the presence of adenosine triphosphate (ATP). 2. The method of claim 1 wherein the step of cleaning comprises the step of cleaning textiles with a water solution in a cleaning vessel whereby the water solution becomes used; and the step of testing comprises the step of testing the used water solution for the presence of ATP while the textiles remain in the cleaning vessel. 3. The method of claim 2 further comprising the step of cleaning the textiles further with a subsequent water solution if an amount of the ATP detected in the step of testing exceeds a predetermined acceptable level. 4. The method of claim 3 further comprising the step of testing the subsequent water solution for the presence of ATP. 5. The method of claim 4 further comprising the step of removing the textiles from the cleaning vessel if an amount of the ATP detected in the step of testing the subsequent water solution does not exceed the predetermined acceptable level. 6. The method of claim 2 further comprising the step of removing the textiles from the cleaning vessel if an amount of the ATP detected in the step of testing does not exceed a predetermined acceptable level. 7. The method of claim 6 further comprising, absent re-contamination of the textiles, the steps of drying and finishing the cleaned textiles to a degree suitable for delivery to a user of the textiles without further sanitizing the textiles after the step of removing. 8. The method of claim 1 wherein the step of cleaning comprises the step of cleaning textiles with a water solution in a cleaning vessel whereby the water solution becomes used; further comprising the step of draining the used water solution from the cleaning vessel; and wherein the step of testing comprises the step of testing the drained water solution. 9. The method of claim 8 wherein the step of draining comprises the step of draining the water solution by force of gravity from the cleaning vessel. 10. The method of claim 1 wherein the step of cleaning comprises the step of cleaning textiles with a water solution in a cleaning vessel whereby the water solution becomes used; further comprising the steps of draining the used water solution by force of gravity from the cleaning vessel; and extracting a further amount of the used water solution from the drained textiles; and wherein the step of testing comprises the step of testing the extracted water solution. 11. The method of claim 10 wherein the step of extracting comprises the step of spinning the textiles to release the further amount of the used water solution by centrifugal force. 12. The method of claim 1 wherein the step of cleaning comprises the step of cleaning textiles with a first water solution for a first cleaning period; and further comprising the steps of draining the first water solution; cleaning the textiles with a second water solution for a second cleaning period; and wherein the step of testing comprises the step of testing the second water solution for the presence of ATP. 13. The method of claim 12 wherein the step of testing comprises the step of testing the second water solution for the presence of ATP without testing the first water solution for the presence of ATP. 14. The method of claim 1 wherein the step of testing comprises the step of assaying the used water solution for the presence of ATP by mixing the used water solution with luciferase and luciferin. 15. The method of claim 1 wherein the step of testing comprises the step of assaying the used water solution for the presence of ATP by mixing the used water solution with a buffer which accelerates the release of ATP. 16. The method of claim 1 wherein the step of testing comprises the step of testing the used water solution for the presence of ATP with a luminometer. 17. The method of claim 16 further comprising the steps of wetting a swab with the used water solution; and creating a bioluminescent reaction with the used water solution from the wetted swab which is detectable by the luminometer. 18. The method of claim 1 wherein the step of testing is performed before the textiles are dried. 19. A method comprising the steps of: cleaning textiles with a water solution whereby the water solution becomes used; and testing the used water solution to determine a level of contaminants therein in no more than 15 minutes. 20. A method comprising the steps of: cleaning textiles with a water solution in a cleaning vessel whereby the water solution becomes used; and testing the used water solution to determine a level of contaminants therein while the textiles remain in the cleaning vessel.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Technical Field The present invention relates generally to the laundering of textiles. More particularly, the invention relates to the insurance of an acceptable level of cleanliness of the textiles. Specifically, the invention relates to the testing of the water solution in which the textiles are cleaned for the presence of adenosine triphosphate (ATP). 2. Background Information In the field of industrial laundering, there is a need to ensure that textiles which are laundered meet certain standards of cleanliness. Of particular concern is the amount of bacteria on the laundered textiles although the amount of other contaminants is also important. Testing for the presence of adenosine triphosphate (ATP) is a useful indicator of various contaminants including bacteria because ATP delivers energy to all living organisms and is found in organisms both living and dead. One of the current primary test methods involves the direct testing of textiles which have been laundered and dried. In particular, test procedures have been developed which utilize a swab rubbed directly on textiles in order to obtain a test sample of ATP therefrom. A luminometer is then used to quickly analyze the concentration or amount of ATP on the swab. A test kit using such a swab is described in greater detail in U.S. Pat. No. 6,180,395 granted to Skiffington et al., which is incorporated herein by reference. This test method provides rapid results and thus is a great advantage over the relatively slow process of bacterial colony growth, which usually takes about two days and is obviously not suitable for the purposes of testing laundered textiles. While such swabbing methods are very convenient, they nonetheless have some drawbacks. One disadvantage is that the testing occurs after the textiles have been dried. Thus, if a given piece or batch of textiles must be re-washed due to an unacceptable ATP level which remained after laundering, that piece or batch of textiles will have already undergone the costly and time consuming step of drying. In addition, the swab testing of a given textile may produce different results depending on where the textile is swabbed. More particularly, a given textile may have been heavily soiled in one area and lightly soiled in another area so that even after laundering, the area which was heavily soiled may retain a greater degree of contamination. In addition, in order to obtain a suitable sample size which is likely to be representative of a large batch of textiles, a fairly large number of textiles must be individually tested in the present swabbing method to minimize concerns related to random sampling. Thus, there is a need in the art to provide a test for sanitation of textiles at an earlier stage of the laundering process while minimizing the number of tests performed.
|
<SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention provides a method comprising the steps of cleaning textiles with a water solution whereby the water solution becomes used; and testing the used water solution for the presence of adenosine triphosphate (ATP). The present invention also provides a method comprising the steps of cleaning textiles with a water solution whereby the water solution becomes used; and testing the used water solution to determine a level of contaminants therein in no more than 15 minutes. The present invention further provides a method comprising the steps of cleaning textiles with a water solution in a cleaning vessel whereby the water solution becomes used; and testing the used water solution to determine a level of contaminants therein while the textiles remain in the cleaning vessel.
|
BACKGROUND OF THE INVENTION 1. Technical Field The present invention relates generally to the laundering of textiles. More particularly, the invention relates to the insurance of an acceptable level of cleanliness of the textiles. Specifically, the invention relates to the testing of the water solution in which the textiles are cleaned for the presence of adenosine triphosphate (ATP). 2. Background Information In the field of industrial laundering, there is a need to ensure that textiles which are laundered meet certain standards of cleanliness. Of particular concern is the amount of bacteria on the laundered textiles although the amount of other contaminants is also important. Testing for the presence of adenosine triphosphate (ATP) is a useful indicator of various contaminants including bacteria because ATP delivers energy to all living organisms and is found in organisms both living and dead. One of the current primary test methods involves the direct testing of textiles which have been laundered and dried. In particular, test procedures have been developed which utilize a swab rubbed directly on textiles in order to obtain a test sample of ATP therefrom. A luminometer is then used to quickly analyze the concentration or amount of ATP on the swab. A test kit using such a swab is described in greater detail in U.S. Pat. No. 6,180,395 granted to Skiffington et al., which is incorporated herein by reference. This test method provides rapid results and thus is a great advantage over the relatively slow process of bacterial colony growth, which usually takes about two days and is obviously not suitable for the purposes of testing laundered textiles. While such swabbing methods are very convenient, they nonetheless have some drawbacks. One disadvantage is that the testing occurs after the textiles have been dried. Thus, if a given piece or batch of textiles must be re-washed due to an unacceptable ATP level which remained after laundering, that piece or batch of textiles will have already undergone the costly and time consuming step of drying. In addition, the swab testing of a given textile may produce different results depending on where the textile is swabbed. More particularly, a given textile may have been heavily soiled in one area and lightly soiled in another area so that even after laundering, the area which was heavily soiled may retain a greater degree of contamination. In addition, in order to obtain a suitable sample size which is likely to be representative of a large batch of textiles, a fairly large number of textiles must be individually tested in the present swabbing method to minimize concerns related to random sampling. Thus, there is a need in the art to provide a test for sanitation of textiles at an earlier stage of the laundering process while minimizing the number of tests performed. BRIEF SUMMARY OF THE INVENTION The present invention provides a method comprising the steps of cleaning textiles with a water solution whereby the water solution becomes used; and testing the used water solution for the presence of adenosine triphosphate (ATP). The present invention also provides a method comprising the steps of cleaning textiles with a water solution whereby the water solution becomes used; and testing the used water solution to determine a level of contaminants therein in no more than 15 minutes. The present invention further provides a method comprising the steps of cleaning textiles with a water solution in a cleaning vessel whereby the water solution becomes used; and testing the used water solution to determine a level of contaminants therein while the textiles remain in the cleaning vessel. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a diagrammatic view of a washing machine and a testing device for testing the water solution drained from within the washing machine. FIG. 2 is a diagrammatic view of the testing device. FIG. 3 is similar to FIG. 1 and shows additional water solution being extracted from the drained textiles and the testing of the extracted water solution. DETAILED DESCRIPTION OF THE INVENTION A first method of the present invention is described with reference to FIGS. 1-2; and a second method is described with reference to FIG. 3. Generally, the methods of the present invention are used to ensure the sanitation or cleanliness of laundered textiles. FIG. 1 shows a cleaning device in the form of a washing machine or washer 10 having a cleaning vessel in the form of a rotatable drum 12 which defines a washer compartment therein in which laundry or textiles 14 may be placed for washing in a water solution 16 which may contain various detergents and chemicals suitable to promote the cleaning of textiles 14. Textiles 14 may be made up of various textiles such as aprons, butcher coats, sheets, towels, surgical garments, napkins, various other types of uniforms, linens, and so forth. A container or catch vessel 18 is disposed below washer 10 to catch the soiled or dirty water solution 16 which is drained (arrow A) from washer 10 subsequent to the washing or laundering of textiles 14. Vessel 18 is initially free of adenosine triphosphate (ATP) prior to catching the soiled water solution 16, commonly known as sour drain. Washing textiles 14 in washer 10 is not the only method or device for cleaning textiles 14, and the process shown in the figures is meant to represent the cleaning of textiles by any method using a water solution. For example, dry cleaning utilizes a water solution having dry cleaning chemicals therein to achieve the cleaning process. The present test method may be used to test the used water solution from the dry cleaning process as well. In addition, newly manufactured textiles are typically cleaned by dipping them in a cleaning solution at the manufacturing textile mill. At least the final solution used in this cleaning process involves a water solution which may also be tested by the present method. An ATP tester 20 is used to test the drained solution 16. In the exemplary embodiment, tester 20 includes a luminometer 22, a sample cylinder 24 and a swab 26 which is removably insertable into cylinder 24 and held by handle 27. Depending on the specific test, the cylinder and/or swab may be inserted into the luminometer 22, or, for instance, a portion of cylinder 24 may be inserted into luminometer 22. One such tester is described in the afore mentioned U.S. Pat. No. 6,180,395, which as previously mentioned is incorporated herein by reference. Such testing devices are sold by Charm Sciences, Inc. of Malden Mass. under the names Pocketswab® Plus, Watergiene® and Allergiene®. Another portable swab-type device used in an ATP bioluminescent test is sold under the name Lightning® by Idexx Laboratories, Inc. of Westbrook, Me. These swab-type devices typically have a pre-moistened swab for gathering a test sample which is mixed within a tube such as cylinder 24 with a buffer solution and luciferin-luciferase test reagents which provides for bioluminescence which is read by the luminometer in relative light units (RLU). The Pocketswab® device utilizes a buffer to facilitate the rapid release of ATP from any organic source including micro-organisms and a neutralizer buffer for optimizing the luciferin-luciferase reaction. Various other ATP tests are also available. Other bioluminescent ATP tests include one which is described in “The Handbook of ATP-Hygiene Monitoring” by Bio-Orbit Oy of Turku, Finland; and one known as the Charm ABC Swab Test sold by the above referenced Charm Sciences, Inc. As further shown in FIG. 1, swab 26 is dipped in or otherwise wetted by the drained water solution 16, reinserted into cylinder 24 and mixed with the appropriate buffer solution and luciferin-luciferase reagents in order to provide the bioluminescence which is then measured by luminometer 22. FIG. 2 shows that luminometer 22 has a display 28 on which is displayed a specific read out or result 30 of the ATP detected from swab 26, measured in RLU's. Once the sample is placed in luminometer 22, it takes only about five seconds to obtain result 30. A predetermined acceptable level of ATP is typically stored within luminometer 22 and compared with result 30 so that luminometer 22 may also display a pass or fail indication. If the ATP level is below the acceptable predetermined value, textiles 14 are then removed from washer 10 and dried in a dryer typically heated by a gas or electric heat source. This may be followed by various finishing steps, such as ironing, pressing, steaming such as through a steam tunnel, and the hanging of textiles such as garments on hangers and enclosure of the textiles within bags, boxes or the like. Preferably, no additional sanitizing steps are required after removing the textiles from the washer, as detailed further below. However, if the ATP level is greater than the acceptable value, textiles 14 will be re-washed or otherwise additionally cleaned and retested in the same manner until the test result is within an acceptable range. Typically, textiles 14 go through multiple cleaning or washing cycles which include washing, draining, rinsing and possibly extraction by centrifuge or the spinning of drum 12 at relatively high speeds. Based on previous testing and general knowledge within the field, personnel within the field of laundering may already know that for a given type of textiles, it will take a certain number of washes and rinses in order to approach the degree of sanitation desired. Thus, a given load of textiles may be washed and rinsed more than once and often many times before the drain water solution is tested for ATP. Because the various types of tests used in the present invention are relatively quick, generally taking no more than five or ten minutes and potentially even less, the testing of the drained water solution will normally be done while the textiles remain in the washer. Preferably, the testing period takes no more than 15 minutes. Referring to FIG. 3, the second method of testing is described. The second method is very similar to the first method except that the water solution which is tested is that which is extracted from textiles 14 after the standard drain of solution 16 by gravity and/or pumping thereof. More particularly, drum 12 goes through a spinning cycle, or is rotated at relatively high speeds in order to extract additional water solution 16 from textiles 14 via a centrifuge effect or centrifugal force. Rotation of drum 12 is shown at arrows B and the extracted solution is indicated at arrow C. The extracted solution 16 is then drained into vessel 18 and tested in the same manner as described above. TABLE 1 Comparison of Test Locations Test Location Dry Soiled Textile Test Vessel Washer Drain ATP (RLU) 173,387 835,793 5,444,266 Hach Test Kit <100 100,000 1,000,000 (CFU) Table 1 Notes: 1. The “dry soiled textile” test was performed prior to being washed; the “test vessel” test was of soiled water solution extracted from a textile which was placed in a water solution in a vessel and stirred or slightly agitated; and the “washer drain” test was a test of soiled water solution drained from the washer in which the textile was washed, the latter being indicative of a high degree of agitation. 2. All ATP results from a swab method with readings from a NovaLum ® luminometer. 3. Hach Test Kit readings were taken after 48 hours of bacterial growth and reported as colony-forming units (CFU). In particular, the tests were done with a Hach Paddle Tester, Total Aerobic Bacteria/Disinfection Control Test Kit sold by the Hach Company of Loveland, CO. Table 1 primarily shows that the test of the dry soiled textile is generally inaccurate and thus may be misleading. As will be appreciated, even when the test of the dry textile is performed with a pre-moistened swab, the testing of the textile directly, especially when dry, is essentially a surface test which will not indicate the level of ATP or various contaminants further entrapped within the fibers of the cloth. The “test vessel” test shows that even a small degree of agitation of the dirty textile in a water solution allows various contaminants to be released or extracted therefrom to a notably greater degree than possible from the swabbing of the dry soiled textile. The soiled washer drain solution shows a far greater amount of ATP which is in keeping with the ability of the high-agitation washer to strip all sorts of contaminants from the fabric via mechanical action, solubility in water and/or the entrainment of the contaminants in the water solution. The results from the Hach test kit provide a similar comparison. In addition, the test results from the Hach test kit indicate that the dry soiled textile may actually be within an acceptable range of sanitation which would be expected only subsequent to the textile being washed. The results from Table 1 thus emphasize the need for a test which better establishes a more accurate reading of the ATP level in the textiles. TABLE 2 ATP Test Results of Various Textile Types Max. Sour Wet Capacity Drain Textile (lbs. clean Textile No. of Test Test Washer dry cotton) Type Steps (RLU) (RLU) #1 450 white 21 39624 0 industrial #2 450 65/35 17 9510 — shirts #3 600 colored 15 40000 0 cotton #4 600 65/35 13 18034 0 pants Table 2 Notes: 1. The term “65/35” stands for 65% polyester and 35% cotton; typically, the white industrial textile type is of a 65/35 blend. 2. The number of steps typically includes a combination of washing, draining, rinsing and spinning in various orders depending on the textile type. 3. Tests performed via Pocketswab ® Plus method with readings provided by a NovaLum ® luminometer. 4. In the sour drain test, the swab was wetted with the soiled water solution drained from the washer after the final step indicated in the number of steps column. 5. In the wet textile test, the swab was rubbed on the wet textile which was still wet with the water solution of the wash after the final step of washing. As Table 2 shows with reference to the Pocketswab® Plus test, even when the sour drain test gave an ATP reading of 40,000 RLU, the test of the wet textile gave an ATP reading of 0 RLU. This further emphasizes the difficulty of obtaining an accurate result concerning the level of contaminants via the direct swabbing of a textile. If the textiles are sufficiently clean at the end of the washing or other cleaning process, there is no need, absent any re-contamination of textiles, for additional sanitizing steps thereafter. This is the most preferred condition of the textiles subsequent to washing or other cleaning in order to eliminate these additional sanitizing steps which may be relatively costly. Thus, it is preferred to maintain the textiles in a sanitary condition during the process of drying and all of the finishing steps and delivery to the customer or user of the textiles without additional sanitization. Applicant's method of ATP testing thus provides a more accurate indicator of the level of ATP and associated bacteria of laundered textiles than do tests based on the direct swabbing of the textile. In addition, the textiles are tested for ATP at an earlier stage of the laundering process which can avoid the unnecessary repetition of various steps of the laundering process. Moreover, the present method may eliminate the need for sanitizing procedures subsequent to the washing or other cleaning process while maintaining a level of sanitation equal to or better than that of the prior art methods. In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.
|
G
|
G01
|
G01N
|
33
|
36
|
|||
11678476
|
US20080209242A1-20080828
|
MODEM CARD CONFIGURED TO COMPENSATE FOR POWER SUPPLY
|
ACCEPTED
|
20080814
|
20080828
|
[]
|
G06F132
|
["G06F132", "G06F126"]
|
7876814
|
20070223
|
20110125
|
375
|
222000
|
70649.0
|
LUGO
|
DAVID
|
[{"inventor_name_last": "Rodriguez", "inventor_name_first": "Romeo Hernandez", "inventor_city": "San Diego", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Matsuo", "inventor_name_first": "Kotaro", "inventor_city": "Poway", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Nergis", "inventor_name_first": "Aydin", "inventor_city": "San Diego", "inventor_state": "CA", "inventor_country": "US"}]
|
A modem card includes a connector configured to be detachably connected to a computer. The card also includes electronics configured to be powered by a power supply located in the computer and to transmit wireless signals to a communications network at a transmit power. The electronics are configured to vary the transmit power such that the transmit power does not exceed a maximum transmit power. Increases in the transmit power cause a drop in the voltage of the power. The electronics are also configured to determine an adjusted maximum transmit power. The adjusted maximum transmit power is a transmit power at which the signals can be transmitted to the communications system without the voltage dropping below a shut-down voltage. The electronics are also configured to reduce the value of the maximum transmit power to a value that that is less than or equal to the value for the adjusted maximum transmit power.
|
1. A modem card, comprising: a connector configured to be connected to a computer; electronics configured to be powered by power supplied from a power supply located in the computer; and the electronics being configured to transmit wireless signals to a communications network, the signals being transmitted at a transmit power, vary the transmit power such that the transmit power does not exceed a maximum transmit power, the transmit power being varied such that a voltage of the power drops in response to increases in the transmit power, determine a value for an adjusted maximum transmit power, the adjusted maximum transmit power being a transmit power at which the signals can be transmitted to the communications system without the voltage dropping below a shut-down voltage, reduce a value of the maximum transmit power to a value that that is less than or equal to the value determined for the adjusted maximum transmit power. 2. The card of claim 1, wherein determining the adjusted maximum transmit power includes: increasing the transmit power to a revised transmit power where the power falls below a voltage threshold, the voltage threshold being equal to or greater than the shut-down voltage, and the revised transmit power being less than the maximum transmit power; repeatedly reducing the revised transmit power and transmitting the wireless signals to the communications system using the revised transmit powers, determining the voltage that results from each revised transmit power, and treating one of the revised transmit powers that result in a voltage that is at least equal to the voltage threshold as the adjusted maximum transmit power. 3. The card of claim 1, wherein determining the adjusted maximum transmit power includes: increasing the transmit power to a revised transmit power; transmitting the wireless signals at the revised transmit power; determining the voltage that results from transmitting the wireless signals at the revised transmit power; and determining whether the determined voltage is below a voltage threshold that is at least equal to the shut-down voltage. 4. The card of claim 3, wherein determining the adjusted maximum transmit power includes: decreasing the revised transmit power in response to determining that the determined voltage is below the voltage threshold. 5. The card of claim 3, wherein determining the adjusted maximum transmit power includes: treating the revised transmit powers as the adjusted maximum transmit power in response to determining that the determined voltage is at least equal to the voltage threshold. 6. The card of claim 3, wherein the electronics are configured to receive signals from the communications network; and increasing the transmit power to a revised transmit power is performed in response to the electronics receiving a signal from the communications network which requests that the electronics increase the transmit power. 7. The card of claim 3, wherein the voltage threshold is equal to the shut-down voltage. 8. The card of claim 3, wherein the voltage threshold is greater than the shut-down voltage. 9. The card of claim 1, wherein a set maximum transmit power is stored in the electronics and is not calculated by the electronics but is used as the maximum transmit power at some time during operation of the card, the adjusted maximum transmit power being determined to have a value that is different from a value of the set maximum transmit power. 10. A computer system, comprising: a computer having a power supply that provides power having a voltage; and a modem card removably connected to the computer, the modem card including electronics powered by the power from the power supply, the electronics being configured to transmit wireless signals to a communications network, the signals being transmitted at a transmit power, vary the transmit power such that the transmit power does not exceed a maximum transmit power, increases in the transmit power causing a drop in the voltage of the power, determine a value for an adjusted maximum transmit power, the adjusted maximum transmit power being a transmit power at which the signals can be transmitted to the communications system without the voltage dropping below a shut-down voltage, reduce a value of the maximum transmit power to a value that that is less than or equal to the value for the adjusted maximum transmit power. 11. The system of claim 10, wherein determining the adjusted maximum transmit power includes: increasing the transmit power to a revised transmit power where the power falls below a voltage threshold, the voltage threshold being equal to or greater than the shut-down voltage, and the revised transmit power being less than the maximum transmit power; repeatedly reducing the revised transmit power and transmitting the wireless signals to the communications system using the revised transmit powers, determining the voltage that results from each revised transmit power, and treating one of the revised transmit powers that result in a voltage that is at least equal to the voltage threshold as the adjusted maximum transmit power. 12. The system of claim 10, wherein determining the adjusted maximum transmit power includes: increasing the transmit power to a revised transmit power; transmitting the wireless signals at the revised transmit power; determining the voltage that results from transmitting the wireless signals at the revised transmit power; and determining whether the determined voltage is below a voltage threshold that is at least equal to the shut-down voltage. 13. The system of claim 12, wherein determining the adjusted maximum transmit power includes: decreasing the revised transmit power in response to determining that the determined voltage is below the voltage threshold. 14. The system of claim 12, wherein determining the adjusted maximum transmit power includes: treating the revised transmit powers as the adjusted maximum transmit power in response to determining that the determined voltage is at least equal to the voltage threshold. 15. A method of operating a modem card, comprising: transmitting wireless signals to a communications network, the signals being transmitted at a transmit power; varying the transmit power such that the transmit power does not exceed a maximum transmit power, the transmit power being varied such that a voltage of the power drops in response to increases in the transmit power; determining an adjusted maximum transmit power, the adjusted maximum transmit power being a transmit power at which the signals can be transmitted to the communications system without the voltage dropping below a shut-down voltage; and changing a value of the maximum transmit power to the value of the adjusted maximum transmit power. 16. The method of claim 15, wherein determining the adjusted maximum transmit power includes: increasing the transmit power to a revised transmit power where the power falls below a voltage threshold, the voltage threshold being equal to or greater than the shut-down voltage, and the revised transmit power being less than the maximum transmit power; repeatedly reducing the revised transmit power and transmitting the wireless signals to the communications system using the revised transmit powers; determining the voltage that results from each revised transmit power; and treating one of the revised transmit powers that result in a voltage that is at least equal to the voltage threshold as the adjusted maximum transmit power. 17. The method of claim 15, wherein determining the adjusted maximum transmit power includes: increasing the transmit power to a revised transmit power; transmitting the wireless signals at the revised transmit power; determining the voltage that results from transmitting the wireless signals at the revised transmit power; and determining whether the determined voltage is below a voltage threshold that is at least equal to the shut-down voltage. 18. The method of claim 17, wherein determining the adjusted maximum transmit power includes decreasing the revised transmit power in response to determining that the determined voltage is below the voltage threshold. 19. The method of claim 17, wherein determining the adjusted maximum transmit power includes treating the revised transmit powers as the adjusted maximum transmit power in response to determining that the determined voltage is at least equal to the voltage threshold. 20. A program product for a modem card, the program product comprising: computer-executable logic contained on a computer-readable medium and configured for causing the following computer-executed operations to occur: transmitting wireless signals to a communications network, the signals being transmitted at a transmit power; varying the transmit power such that the transmit power does not exceed a maximum transmit power, the transmit power being varied such that a voltage of the power drops in response to increases in the transmit power; determining an adjusted maximum transmit power, the adjusted maximum transmit power being a transmit power at which the signals can be transmitted to the communications system without the voltage dropping below a shut-down voltage; and changing a value of the maximum transmit power to the value of the adjusted maximum transmit power.
|
<SOH> BACKGROUND <EOH>Modem cards allow a computer to wirelessly communicate with a communications system. During operation of the modem card, the modem card transmits wireless signals to the communications system. In some instances, the communications system requests that the PC card increase the transmit power of the signals. The modem card can increase the transmit power up to a maximum transmit power. The maximum transmit power is generally set by the manufacturer of the modem card. Modem cards are powered by a power supply located in the computer to which the modem card is connected. Increasing the transmit power of the modem card increases the current draw from the modem card. As a result, the increased transmit power can cause a drop in the voltage of the power being supplied to the modem card by the computer (supplied voltage). Different computer manufacturers use different power supplies. As a result, increasing the transmit power to the maximum transmit power causes the supplied voltage to drop to different levels in different computers. In some computers, the supplied voltage can drop below a shut-down voltage where the computer shuts down the computer or the modem card. As a result, there is a need for modem cards that compensate for variation in the power supplies used in different computers.
|
<SOH> SUMMARY <EOH>A modem card includes a connector configured to be detachably connected to a computer. The modem card also includes electronics configured to be powered by a power supply located in the computer. The electronics are configured to transmit wireless signals to a communication network at a transmit power level. The electronics are configured to vary the transmit power such that the transmit power does not exceed a maximum transmit power. Increases in the transmit power cause a drop in the voltage of the power supplied to the modem card. The electronics are also configured to determine an adjusted maximum transmit power. The adjusted maximum transmit power is a transmit power at which the signals can be transmitted to the communications system without the voltage dropping below a shut-down voltage. The electronics are also configured to reduce the value of the maximum transmit power to a value that that is less than or equal to the value for the adjusted maximum transmit power.
|
TECHNICAL FIELD The present invention relates to computer peripheral devices and more particularly to modem cards. BACKGROUND Modem cards allow a computer to wirelessly communicate with a communications system. During operation of the modem card, the modem card transmits wireless signals to the communications system. In some instances, the communications system requests that the PC card increase the transmit power of the signals. The modem card can increase the transmit power up to a maximum transmit power. The maximum transmit power is generally set by the manufacturer of the modem card. Modem cards are powered by a power supply located in the computer to which the modem card is connected. Increasing the transmit power of the modem card increases the current draw from the modem card. As a result, the increased transmit power can cause a drop in the voltage of the power being supplied to the modem card by the computer (supplied voltage). Different computer manufacturers use different power supplies. As a result, increasing the transmit power to the maximum transmit power causes the supplied voltage to drop to different levels in different computers. In some computers, the supplied voltage can drop below a shut-down voltage where the computer shuts down the computer or the modem card. As a result, there is a need for modem cards that compensate for variation in the power supplies used in different computers. SUMMARY A modem card includes a connector configured to be detachably connected to a computer. The modem card also includes electronics configured to be powered by a power supply located in the computer. The electronics are configured to transmit wireless signals to a communication network at a transmit power level. The electronics are configured to vary the transmit power such that the transmit power does not exceed a maximum transmit power. Increases in the transmit power cause a drop in the voltage of the power supplied to the modem card. The electronics are also configured to determine an adjusted maximum transmit power. The adjusted maximum transmit power is a transmit power at which the signals can be transmitted to the communications system without the voltage dropping below a shut-down voltage. The electronics are also configured to reduce the value of the maximum transmit power to a value that that is less than or equal to the value for the adjusted maximum transmit power. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a computer system configured to transmit wireless signals to a communications system. The computer system includes a modem card connected to a computer such that the computer provides power to electronics in the modem card. FIG. 2 is a graph illustrating a hypothetical relationship between the transmit power of the wireless signals and the voltage of the power that the computer supplies to the modem card. FIG. 3 is a flow chart for a method of operating the modem card. DETAILED DESCRIPTION A modem card is configured to be detachably connected to a computer. When the modem card is connected to the computer, a power supply in the computer provides power to the modem card (supplied power). The supplied power powers the operation of electronics in the modem card. The electronics employ the supplied power to transmit wireless signals to a communications system. The modem card can vary the transmit power of the signals up to a maximum transmit power. Increasing the transmit power reduces the voltage of the supplied power. The modem card determines an adjusted maximum transmit power. The adjusted maximum transmit power is a transmit power at which the signals can be transmitted to the communications system without the voltage of the supplied power dropping below a shut-down voltage. The modem card changes the value of the maximum transmit power from a set maximum transmit power to a value that is at most equal to the value of the adjusted maximum transmit power. As a result, the modem card transmits signals using a maximum transmit power that is less than or equal to the adjusted maximum transmit power. Accordingly, the electronics can increase the transmit power to the maximum transmit power without the voltage of the supplied power dropping below a shut-down voltage. The modem card can determine a different adjusted maximum transmit power for different power supplies and accordingly for different computers. As a result, the ability of the modem card to increase the transmit power to the maximum transmit power without the voltage of the supplied power dropping below the shut-down voltage is independent of the computer being employed. FIG. 1 illustrates a computer system 10 in wireless communication with the base station 12 of a wireless communications system 14. The computer system 10 includes a modem card 16 in communication with a computer 18. The modem card 16 enables the computer 18 to wirelessly communicate with the wireless communications system 14 over a wireless air-link. Examples of suitable wireless communications systems 14 include, but are not limited to, code-division multiple access (CDMA) based networks. Suitable computers 18 include laptop computers and notebook computers but can also include other computers 18 that employ modem cards 16 to communicate with wireless communication systems such as game systems and office equipment. Suitable modem cards 16 includes, but are not limited to, Personal Computer 18 Memory Card International Association (PCMCIA cards or PC cards) having wireless modem capabilities, Express Cards having wireless modem capabilities, Miniature Cards (Mini Cards) having wireless modem capabilities, and Express Mini Cards or Mini Express Cards having wireless modem capabilities. The modem card 16 includes a connector 20 that permits the modem card 16 to be detachably connected to a connector 22 in the computer 18. For instance, PC cards typically employ a 68-contact, dual row pin and socket connector while an Express Card typically employs a 26-contact beam on blade connector. The computer 18 can optionally include a port or a slot configured to receive all or a portion of the modem card 16. The connector 22 can be positioned in the port or slot such that the connector 20 on the modem card 16 is connected with the connector 22 on the computer 18. The computer 18 includes a power supply 24 that provides power to electronics 32 in the modem card 16 through the connector 20. For instance, modem cards 16 typically operate at about 5 V or 3.3 V. In some instances, the power supply 24 provides power to the modem card 16 at about 5 V or at about 3.3 V. The electronics 32 include a processor 34 in communication with a voltmeter 35. The processor 34 can employ the voltmeter to monitor, measure, and/or determine the voltage of the power being supplied to the modem card 16. A suitable processor 34 includes, but is not limited to, a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions attributed to the electronics 32 and/or the processor 34. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor 34 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The electronics 32 include a transceiver 36 in communication with an antenna 37. The processor 34 is in communication with the transceiver. The processor 34 can employ the transceiver 36 to wirelessly transmit signals to the communications system 14 and to wirelessly receive signals from the communications system 14. As an alternative to the transceiver 36, the electronics 32 can be in communication with a receiver and a transmitter. The electronics 32 include a memory 38 in communication with the processor 34. The electronics 32 can store data for communicating with the communications system 14 in the memory 38. For instance, a maximum transmit power can be stored in the memory. The memory 38 can be any memory device or combination of memory devices suitable for read/write operations. In some instances, the electronics 32 include a computer-readable medium 40 in communication with the processor 34. The computer-readable medium 40 can have a set of instructions to be executed by the processor 34. The processor 34 can execute the instructions such that the electronics 32 perform desired functions such as executing a request for packet a data service originated by the user. Although the computer-readable medium 40 is shown as being different from the memory, the computer-readable medium 40 can be the same as the memory 38. Suitable computer-readable media 38 include, but are not limited to, optical discs such as CDs, magnetic storage diskettes, Zip disks, magnetic tapes, RAMs, and ROMs. During operation of the modem card, the modem card communicates with the communications system. Communication with the communications system can include the modem transmitting signals to the communications system and receiving signals from the communications system. During communication with the communications system, the communications system may determine that the signals transmitted by the computer are undesirably weak. In response, the communications system sends the computer a signal requesting that the modem card increase the transmit power for the signals transmitted from the modem card. The transmit power is the signal power at the output of the antenna 37 is typically measured in units such as dBm or watts. Increasing the transmit power can cause a drop in the voltage of the power supplied to the modem card. For instance, FIG. 2 is a graph illustrating a hypothetical relationship between transmit power and the voltage of the power supplied to the modem card (supplied voltage). The transmit power is shown on the x-axis of FIG. 2. The supplied voltage is shown on the y-axis of FIG. 2. Curve 50 in FIG. 2 shows the supplied voltage decreasing as the transmit power increases. As a result, the communications system requesting that the modem card increases the transmit power can cause a drop in the voltage supplied to the modem card. A set maximum transmit power is labeled in FIG. 2. The “set maximum transmit power” is typically set before the modem card is commercially available. For instance, the “set maximum transmit power” is typically programmed into the electronics by the manufacturer of the modem card or the manufacturer of the electronics. As a result, the set maximum transmit power is not calculated by the electronics. During operation of the modem card, the transmit power can be increased to a maximum transmit power. At one or more times during the operation of the card, the card may be asked to increase the transmit power to the set maximum transmit power. However, as is evident from FIG. 2, increasing the transmit power to the set maximum power can cause the voltage to drop below a shut-down voltage that is also labeled in FIG. 2. The reason for this voltage drop involves how the notebook system is designed. For example, PCMCIA specs call for 3.3V supply that supports up to 1 amp current draw. However, the supply for some notebooks falls below the 3.3V specification at a 1 amp current draw. When the voltage falls below the shut-down voltage, some computers shut down the modem card. Other computers may shut down the computer. For instance, some computers may re-start the computer when the supplied voltage falls below the shut-down voltage. As a result, the communications system requesting that the modem card increase the transmit power can cause the computer to shut down the computer or the modem card. The shut-down voltage varies between notebook designs. For example, notebook computers with a PCMCIA slot and a 3.3V supply, typically have a shut down voltage between 2.7V and 3.0V. The electronics adjust the value of the maximum transmit power relative to an adjusted maximum transmit power. The electronics determine the adjusted maximum transmit power such that the transmit power does not increase to a level where the supplied voltage falls below the shut-down voltage. For instance, the electronics can initially use the set maximum transmit power as the maximum transmit power and then adjust the maximum transmit power down to a value that is less than or equal to the adjusted maximum transmit power labeled in FIG. 2. The adjusted maximum transmit power is selected such that even when the transmit power is raised to the adjusted maximum transmit power, the voltage does not drop to the shut-down voltage. For instance, the adjusted maximum transmit power of FIG. 2 results in a voltage that is greater than the shut-down voltage. The electronics can determine the adjusted maximum transmit power using an iterative process. For instance, the electronics can employ a voltage threshold illustrated in FIG. 2. When the electronics responding to requests to increases the transmit power causes the supplied voltage to drop below the voltage threshold, the electronics reduce the transmit power to a revised transmit power. Each time the electronics generate a revised transmit power, the electronics transmit signals at the revised transmit power and determines the voltage of the supplied power that results from transmitting the signals at the revised transmit power. The value of the revised transmit power is repeatedly reduced until one or more of the revised transmit powers results in a supplied voltage that is at least equal to the voltage threshold. The adjusted maximum transmit power is set to a value that is at most equal to the value of one of the revised transmit powers that results in a supplied voltage that is at least such that the supplied voltage is at or above the voltage threshold. As shown by arrow designation 52 in FIG. 2, the voltage threshold is selected to be greater than or equal to the shut-down voltage. Since the adjusted maximum transmit power results in a supplied voltage that is at or above the voltage threshold and the voltage threshold is greater than or equal to the shut-down voltage, the adjusted maximum transmit power results in a supplied voltage that is greater than or equal to the shut down voltage. Accordingly, the adjusted maximum transmit voltage is selected to reduce events where the computer shuts itself down and/or shuts down the modem card. The voltage threshold is preferably above the shut down voltage. As is evident from the above description, the supplied voltage can fall below the voltage threshold during the process of determining the adjusted maximum transmit power. In some instances, a voltage threshold above the shut-down voltage may prevent the supplied voltage from falling below the shut-down voltage while determining the adjusted maximum transmit power. Curve 50 illustrated in FIG. 2 may vary as a result of the outer resources and/or peripherals to which the computer is providing power. For instance, the drop in the voltage supplied to the modem may become more rapid as the computer increases the power supplied to resources and/or peripherals other than the modem card. As a result, the computer can continue to determine a new adjusted maximum transmit power when the communications system requests that the modem card increase the transmit power. FIG. 3 is a flow chart for a method of operating a modem card. At process block 100, the power supply in the computer supplies power to the electronics in the modem card. At process block 102 the electronics begin communicating with a communications system. When the electronics proceed from process block 100 to process block 102, an initial transmit power serves as the maximum transmit power for communicating with the communications system. The set maximum transmit power can serve as the initial maximum transmit power. Alternately, a maximum transmit power that was previously determined by the electronics can serve as the initial maximum transmit power. At determination block 104, the electronics make a determination whether the modem card has received a request for increased transmit power from the communications system. When the determination is negative, the electronics continue communicating with the communications system at process block 102. When the determination at determination block 104 is positive, the electronics determine a revised transmit power at process block 106. The revised transmit power is determined so as to have a transmit power between the transmit power employed at process block 104 and the maximum transmit power or has a value equal to the maximum power. At process block 108, the modem card transmits signals at the revised transmit power. At determination block 110, the electronics determine whether transmitting signals at the revised transmit power results in an undesirable drop in the supplied voltage. For instance, the electronics can determine the voltage of the power being supplied to the modem card from the power supply. The electronics can compare the voltage to the voltage threshold. The determination at determination block 110 can be positive when the determined voltage is at or below the voltage threshold and the determination at determination block 110 can be negative when the determined voltage exceeds the voltage threshold. When the determination at determination block 110 is negative, the electronics returns to process block 102 and continues to communicate with the communication using the revised transmit power and the maximum transmit power that is currently being employed. When the determination at determination block 110 is positive, the electronics determine the adjusted maximum transmit power at process block 111. Process block 111 includes process blocks 112 where the value of the revised transmit power is reduced. For instance, the revised transmit power can be decreased by a pre-determined increment. At process block 114, the electronics transmit signals to the communications system at the revised transmit power. At determination block 116, the electronics determine whether transmitting signals at the revised transmit power results in an undesirable drop in the supplied voltage. For instance, the electronics can determine the voltage of the power being supplied to the modem card from the power supply. The electronics can compare the determined voltage to a voltage threshold. The voltage threshold can be the same or different from the voltage threshold of determination block 110. The determination at determination block 116 can be positive when the determined voltage is at or below the voltage threshold and the determination at determination block 116 can be negative when the determined voltage exceeds the voltage threshold. When the determination is positive, the electronics return to process block 112. When the determination at determination block 116 is negative, the electronics reduce the value of the maximum transmit power at process block 118. For instance, the electronics can treat the revised transmit power as an adjusted maximum transmit power. The electronics can adjust the value of the maximum transmit power to a value that is less than or equal to the adjusted maximum transmit power. In some instances, the electronics adjust the value of the maximum transmit power to a value that is equal to the value of the adjusted maximum transmit power. In the event that the electronics adjust the value of the maximum transmit power to a value that is less than the value of the adjusted maximum transmit power, the electronics can multiply the adjusted maximum transmit power by a factor that is less than 1 or subtract a factor from the adjusted maximum transmit power. The electronics proceed from process block 118 to process block 102 where the electronics communicate with the communications system using the maximum transmit power determined at process block 118. Each time the electronics adjust the maximum transmit power, the electronics can store the maximum transmit power in the memory. As a result, the electronics can employ the stored maximum transmit power as the initial transmit power each time the computer is powered on without the modem card being removed from the computer, each time that the modem card is used to communicate with the communications system without the computer being shut down, and/or the next time the modem card is used after being removed from the computer. Additionally or alternately, each time the computer is powered on without the modem card being removed from the computer, each time that the modem card is used to communicate with the communications system without the computer being shut down, and/or the next time the modem card is used after being removed from the computer. All or a portion of the method described above can be executed by the electronics. In some instances, the electronics include a computer-readable medium and instructions for executing all or a portion of the methods disclosed above are included on the computer-readable medium. The processor can execute these instructions during operation of the modem card. Other embodiments and modifications of this invention will occur readily to those of ordinary skill in the art in view of these teachings. The above description is illustrative and not restrictive. This invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
|
G
|
G06
|
G06F
|
1
|
32
|
|||
11889307
|
US20080118835A1-20080522
|
Rechargeable lithium battery
|
ACCEPTED
|
20080509
|
20080522
|
[]
|
H01M440
|
["H01M440", "H01M436", "H01M444", "H01M438"]
|
8808915
|
20070810
|
20140819
|
429
|
231300
|
62258.0
|
WEINER
|
LAURA
|
[{"inventor_name_last": "Hur", "inventor_name_first": "So-Hyun", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "Jung", "inventor_name_first": "Euy-Young", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "Hwang", "inventor_name_first": "Duck-Chul", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "Park", "inventor_name_first": "Yong-Chul", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "Lee", "inventor_name_first": "Jong-Hwa", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "Kim", "inventor_name_first": "Jeom-Soo", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "Ryu", "inventor_name_first": "Jae-Yul", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "Kim", "inventor_name_first": "Jin-Bum", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}]
|
The rechargeable lithium battery includes a positive electrode which includes a positive active material, a negative electrode, and an electrolyte which includes a non-aqueous organic solvent and a lithium salt. The positive active material includes a core including at least one of a compound represented by Formula 1 and a compound represented by Formula 2, and a surface-treatment layer which is formed on the core and includes a compound represented by Formula 3. The lithium salt includes LiPF6 and a lithium imide-based compound. LiaNibCocMndMeO2 (1) LihMn2MiO4 (2) M′xPyOz (3) wherein each of M and M′ is independently selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, 0.95≦a≦1.1, 0≦b≦0.999, 0≦c≦0.999, 0≦d≦0.999, 0.001≦e≦0.2, 0.95≦h≦1.1, 0.001≦i≦0.2, 1≦y≦4, 0≦y≦7, and 2≦z≦30.
|
1. A rechargeable lithium battery comprising: a positive electrode comprising a positive active material being capable of intercalating and deintercalating lithium ions, the positive active material comprising: a core formed of a material comprising at least one of a compound represented by Formula 1 and a compound represented by Formula 2: LiaNibCocMndMeO2 (1) LihMn2MiO4 (2) wherein M is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, 0.95≦a≦1.1, 0≦b≦0.999, 0≦c≦0.999, 0≦d≦0.999, 0.001≦e≦0.2, 0.95≦h≦1.1 and 0.001≦i≦0.2; and a surface-treatment layer formed on the core, the surface-treatment layer comprising a compound represented by Formula 3: M′xPyOz Formula 3 wherein M′ is independently selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 1≦x≦4, 0≦y≦7 and 2≦z≦30; a negative electrode comprising a negative active material being capable of intercalating and deintercalating lithium ions; and an electrolyte comprising a non-aqueous organic solvent and a lithium salt, the lithium salt comprising LiPF6 and a lithium imide-based compound. 2. The rechargeable lithium battery of claim 1, wherein the element M is selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, In, Ti, Si, Ge, Sn, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof. 3. The rechargeable lithium battery of claim 1, wherein the element M is selected from the group consisting of Mg, Ti, Al, and combinations thereof. 4. The rechargeable lithium battery of claim 1, wherein the element M′ is selected from the group consisting of Mg, Ti, Al, and combinations thereof. 5. The rechargeable lithium battery of claim 1, wherein the material of the core has an average particle diameter of 0.1 to 100 μm. 6. The rechargeable lithium battery of claim 1, wherein the compound of Formula 3 comprises at least one selected from the group consisting of Mg2P2O7, Al2O3, AlPO4, and combinations thereof. 7. The rechargeable lithium battery of claim 1, wherein the amount of the compound of Formula 3 is more than or equal to 0.001 wt % and less than 20 wt % based on the total weight of the positive active material. 8. The rechargeable lithium battery of claim 1, wherein the positive electrode has an active mass density of more than or equal to 3.65 g/cc. 9. The rechargeable lithium battery of claim 8, wherein the positive electrode has an active mass density of 3.7 to 4.2 g/cc. 10. The rechargeable lithium battery of claim 1, wherein the lithium imide-based compound is represented by Formula 4: LiN(CpF2p+1SO2)r(CqF2q+1SO2)s (4) wherein 1≦p, 1≦q, 0<r≦3, and 0≦s≦3. 11. The rechargeable lithium battery of claim 10, wherein the lithium imide-based compound is selected from the group consisting of LiN(CF3SO2)2, LiN(C2F5SO2)2, and combinations thereof. 12. The rechargeable lithium battery of claim 1, wherein the LiPF6 and a lithium imide-based compound are present in a weight ratio of 99.9:0.1 to 50:50. 13. The rechargeable lithium battery of claim 1, wherein the lithium salt is included at a concentration of 0.1 to 2.0M. 14. The rechargeable lithium battery of claim 1, wherein the electrolyte further comprises an additional lithium salt selected from the group consisting of LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, LiC4F9SO3, LiAlO4, LiAlCl4, LiSO3CF3, LiCl, Lil, LiB(C2O4)2, and combinations thereof. 15. The rechargeable lithium battery of claim 14, wherein the additional lithium salt comprises 0.01 to 2 parts by weight of LiBF4 based on 100 parts by weight of LiPF6. 16. The rechargeable lithium battery of claim 1, wherein the negative active material comprises at least one selected from the group consisting of lithium, a metal being capable of alloying with lithium, a carbonaceous material, a composite material including the metal and carbonaceous material, and combinations thereof. 17. The rechargeable lithium battery of claim 16, wherein the metal being capable of alloying with lithium is selected from the group consisting of Al, Si, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Ag, Ge, Ti, and combinations thereof. 18. The rechargeable lithium battery of claim 16, wherein the carbonaceous material has an Lc (crystallite size) of at least 20 nm found through X-ray diffraction. 19. The rechargeable lithium battery of claim 16, wherein the carbonaceous material has an exothermic peak at 700° C. or more. 20. The rechargeable lithium battery of claim 16, wherein the carbonaceous material is a carbon material or a graphite fiber. 21. The rechargeable lithium battery of claim 1, wherein the non-aqueous organic solvent comprises an organic solvent selected from the group consisting of a carbonate-based solvent, an ester-based solvent, an ether-based solvent, a ketone-based solvent, an alcohol-based solvent, an aprotic solvent, and combinations thereof. 22. The rechargeable lithium battery of claim 1, which has a charge voltage of 4.3 to 4.5V. 23. A rechargeable lithium battery comprising: a positive electrode comprising a positive active material being capable of intercalating and deintercalating lithium ions, the positive active material comprising: a core formed of a material comprising a compound represented by Formula 1: LiaNibCocMndMeO2 (1) wherein M is selected from the group consisting of an alkali metal, an alkaline-earth metal; a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, 0.95≦a≦1.1, 0≦b≦0.999, 0≦c≦0.999, 0≦d≦0.999, 0.001≦e≦0.2; a surface-treatment layer formed on the core, the surface-treatment layer comprising a compound represented by Formula 3, the amount of the compound of Formula 3 being more than or equal to 0.001 wt % and less than 20 wt % based on the total weight of the positive active material: M′xPyOz (3) wherein M′ is independently selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 1≦x≦4, 0≦y≦7, and 2≦z≦30; a negative electrode comprising a negative active material being capable of intercalating and deintercalating lithium ions; and an electrolyte comprising a non-aqueous organic solvent and a lithium salt, the lithium salt comprising LiPF6 and a lithium imide-based compound, the LiPF6 and a lithium imide-based compound being present in a weight ratio of 99.9:0.1 to 50:50. 24. The rechargeable lithium battery of claim 23, wherein the compound represented by Formula 1 is LiCo0.98Mg0.02O2 or LiCO0.98Mg0.01Ti0.01O2. 25. The rechargeable lithium battery of claim 23, wherein the lithium imide-based compound is represented by Formula 4: LiN(CpF2p+1SO2)r(CqF2q+1SO2)s (4) wherein 1≦p, 1≦q, 0<r≦3, and 0≦s≦3. 26. A rechargeable lithium battery comprising: a positive electrode comprising a positive active material being capable of intercalating and deintercalating lithium ions, the positive active material comprising: a core formed of a material comprising a compound represented by Formula 2: LihMn2MiO4 (2) wherein M is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, 0.95≦h≦1.1, and 0.001≦i≦0.2; and M′xPyOz (3) wherein M′ is independently selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 1≦x≦4, 0≦y≦7 and 2≦z≦30; a negative electrode comprising a negative active material being capable of intercalating and deintercalating lithium ions; and an electrolyte comprising a non-aqueous organic solvent and a lithium salt, the lithium salt comprising LiPF6 and a lithium imide-based compound, the LiPF6 and a lithium imide-based compound being present in a weight ratio of 99.9:0.1 to 50:50.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>(a) Field of the Invention The present invention relates to a rechargeable lithium battery, and more particularly to a rechargeable lithium battery having high capacity and excellent cycle-life characteristics and stability. (b) Description of the Related Art A lithium rechargeable battery has recently drawn attention as a power source of small portable electronic devices. It uses an organic electrolyte solution and thereby has twice as high a discharge voltage as a conventional battery using an alkali aqueous solution, and accordingly has high energy density. For positive active materials of a rechargeable lithium battery, lithium-transition element composite oxides being capable of intercalating lithium ions, such as LiCoO 2 , LiMn 2 O 4 , LiNiO 2 , LiNi 1-x Co x O 2 (0<x<1), LiMnO 2 , and so on have been researched. As for a negative active material of a rechargeable lithium battery, various carbon-based materials such as artificial graphite, natural graphite, and hard carbon have been used, which can all intercalate and deintercalate lithium ions. Graphite of the carbon-based materials increases discharge voltages and energy density for a battery because it has a low discharge potential of −0.2V, compared to lithium. A battery using graphite as a negative active material has a high average discharge potential of 3.6V and an excellent energy density. Furthermore, graphite is most comprehensively used among the aforementioned carbon-based materials since graphite guarantees better cycle life for a battery due to its outstanding reversibility. However, a graphite active material has a low density and consequently a low capacity in terms of energy density per unit volume when using the graphite as a negative active material. Further, it involves some dangers such as explosion or combustion when a battery is misused or overcharged and the like, because graphite is likely to react with an organic electrolyte at a high discharge voltage. In order to solve those problems, a great deal of research on an oxide negative electrode has recently been performed. For example, amorphous tin oxide developed by Japan Fuji Film Co., Ltd. has a high capacity per weight (800 mAh/g). However, this oxide has resulted in some critical defects such as a high initial irreversible capacity of up to 50%. Furthermore, a part of the tin oxide has tended to be reduced into tin metal during the charge or discharge reaction, which exacerbates its acceptance for use in a battery. Referring to another oxide negative electrode, a negative active material of Li a Mg b VO c (0.05≦a≦3, 0.12≦b≦2, 2≦2c-a-2b≦5) is disclosed in Japanese Patent Publication No. 2002-216753. The characteristics of a lithium secondary battery including Li 1.1 V 0.9 O 2 were also presented in the 2002 Japanese Battery Conference (Preview No. 3B05). However, such an oxide negative electrode does not show sufficient battery performance and therefore there has been a great deal of further research into oxide negative materials. The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
|
<SOH> SUMMARY OF THE INVENTION <EOH>One embodiment of the present invention provides an improved rechargeable lithium battery. According to an embodiment of the present invention, provided is a rechargeable lithium battery including a positive electrode including a positive active material being capable of intercalating and deintercalating lithium ions, a negative electrode including a negative active material being capable of intercalating and deintercalating lithium ions, and an electrolyte including a non-aqueous organic solvent and a lithium salt. The positive active material includes a core formed of a material including at least one of a compound represented by Formula 1 and a compound represented by Formula 2, and a surface-treatment layer which is formed on the core and includes a compound represented by the following Formula 3. The lithium salt includes LiPF 6 and a lithium imide-based compound. in-line-formulae description="In-line Formulae" end="lead"? Li a Ni b Co c Mn d M e O 2 Formula 1 in-line-formulae description="In-line Formulae" end="tail"? In the above Formula 1, M is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 0.95≦a≦1.1, 0≦b≦0.999, 0≦c≦0.999, 0≦d≦0.999, and 0.001≦e≦0.2. in-line-formulae description="In-line Formulae" end="lead"? Li h Mn 2 M i O 4 Formula 2 in-line-formulae description="In-line Formulae" end="tail"? In the above Formula 2, M is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 0.95≦h≦1.1 and 0.001≦i≦0.2. in-line-formulae description="In-line Formulae" end="lead"? M′ x P y O z Formula 3 in-line-formulae description="In-line Formulae" end="tail"? In the above Formula 3, M′ is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 1≦x≦4, 0≦y≦7 and 2≦z≦30. The material forming the core may have an average particle diameter ranging from 0.1 to 100 μm. The compound of the above Formula 3 is included in an amount of more than or equal to 0.001 wt % and less than 20 wt % of the total weight of the positive active material. The positive electrode may have an active mass density of more than or equal to 3.65 g/cc. The lithium imide-based compound is represented by the following Formula 4: in-line-formulae description="In-line Formulae" end="lead"? LiN(C p F 2p+1 SO 2 ) r (C q F 2q+1 SO 2 ) s Formula 4 in-line-formulae description="In-line Formulae" end="tail"? In the above Formula 4, 1≦p, 1≦q, 0<r≦3, and 0≦s≦3. The lithium salt includes LiPF 6 and a lithium imide-based compound in a weight ratio of 99.9:0.1 to 50:50. The lithium salt is used at a concentration of 0.1 to 2.0M. The electrolyte may further include a lithium salt selected from the group consisting of LiBF 4 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , LiAlO 4 , LiAlCl 4 , LiSO 3 CF 3 , LiCl, Lil, LiB(C 2 O 4 ) 2 , and combinations thereof. The electrolyte may further include 0.01 to 2 parts by weight of LiBF 4 based on 100 parts by weight of LiPF 6 . The rechargeable lithium battery shows a charge voltage ranging from 4.3 to 4.5V.
|
CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY This application claims priority to and the benefit of Korean Patent Application No. 10-2006-0114543 filed in the Korean Intellectual Property Office on Nov. 20, 2006, the entire content of which is incorporated herein by reference. BACKGROUND OF THE INVENTION (a) Field of the Invention The present invention relates to a rechargeable lithium battery, and more particularly to a rechargeable lithium battery having high capacity and excellent cycle-life characteristics and stability. (b) Description of the Related Art A lithium rechargeable battery has recently drawn attention as a power source of small portable electronic devices. It uses an organic electrolyte solution and thereby has twice as high a discharge voltage as a conventional battery using an alkali aqueous solution, and accordingly has high energy density. For positive active materials of a rechargeable lithium battery, lithium-transition element composite oxides being capable of intercalating lithium ions, such as LiCoO2, LiMn2O4, LiNiO2, LiNi1-xCoxO2 (0<x<1), LiMnO2, and so on have been researched. As for a negative active material of a rechargeable lithium battery, various carbon-based materials such as artificial graphite, natural graphite, and hard carbon have been used, which can all intercalate and deintercalate lithium ions. Graphite of the carbon-based materials increases discharge voltages and energy density for a battery because it has a low discharge potential of −0.2V, compared to lithium. A battery using graphite as a negative active material has a high average discharge potential of 3.6V and an excellent energy density. Furthermore, graphite is most comprehensively used among the aforementioned carbon-based materials since graphite guarantees better cycle life for a battery due to its outstanding reversibility. However, a graphite active material has a low density and consequently a low capacity in terms of energy density per unit volume when using the graphite as a negative active material. Further, it involves some dangers such as explosion or combustion when a battery is misused or overcharged and the like, because graphite is likely to react with an organic electrolyte at a high discharge voltage. In order to solve those problems, a great deal of research on an oxide negative electrode has recently been performed. For example, amorphous tin oxide developed by Japan Fuji Film Co., Ltd. has a high capacity per weight (800 mAh/g). However, this oxide has resulted in some critical defects such as a high initial irreversible capacity of up to 50%. Furthermore, a part of the tin oxide has tended to be reduced into tin metal during the charge or discharge reaction, which exacerbates its acceptance for use in a battery. Referring to another oxide negative electrode, a negative active material of LiaMgbVOc (0.05≦a≦3, 0.12≦b≦2, 2≦2c-a-2b≦5) is disclosed in Japanese Patent Publication No. 2002-216753. The characteristics of a lithium secondary battery including Li1.1V0.9O2 were also presented in the 2002 Japanese Battery Conference (Preview No. 3B05). However, such an oxide negative electrode does not show sufficient battery performance and therefore there has been a great deal of further research into oxide negative materials. The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. SUMMARY OF THE INVENTION One embodiment of the present invention provides an improved rechargeable lithium battery. According to an embodiment of the present invention, provided is a rechargeable lithium battery including a positive electrode including a positive active material being capable of intercalating and deintercalating lithium ions, a negative electrode including a negative active material being capable of intercalating and deintercalating lithium ions, and an electrolyte including a non-aqueous organic solvent and a lithium salt. The positive active material includes a core formed of a material including at least one of a compound represented by Formula 1 and a compound represented by Formula 2, and a surface-treatment layer which is formed on the core and includes a compound represented by the following Formula 3. The lithium salt includes LiPF6 and a lithium imide-based compound. LiaNibCocMndMeO2 Formula 1 In the above Formula 1, M is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 0.95≦a≦1.1, 0≦b≦0.999, 0≦c≦0.999, 0≦d≦0.999, and 0.001≦e≦0.2. LihMn2MiO4 Formula 2 In the above Formula 2, M is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 0.95≦h≦1.1 and 0.001≦i≦0.2. M′xPyOz Formula 3 In the above Formula 3, M′ is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 1≦x≦4, 0≦y≦7 and 2≦z≦30. The material forming the core may have an average particle diameter ranging from 0.1 to 100 μm. The compound of the above Formula 3 is included in an amount of more than or equal to 0.001 wt % and less than 20 wt % of the total weight of the positive active material. The positive electrode may have an active mass density of more than or equal to 3.65 g/cc. The lithium imide-based compound is represented by the following Formula 4: LiN(CpF2p+1SO2)r(CqF2q+1SO2)s Formula 4 In the above Formula 4, 1≦p, 1≦q, 0<r≦3, and 0≦s≦3. The lithium salt includes LiPF6 and a lithium imide-based compound in a weight ratio of 99.9:0.1 to 50:50. The lithium salt is used at a concentration of 0.1 to 2.0M. The electrolyte may further include a lithium salt selected from the group consisting of LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, LiC4F9SO3, LiAlO4, LiAlCl4, LiSO3CF3, LiCl, Lil, LiB(C2O4)2, and combinations thereof. The electrolyte may further include 0.01 to 2 parts by weight of LiBF4 based on 100 parts by weight of LiPF6. The rechargeable lithium battery shows a charge voltage ranging from 4.3 to 4.5V. BRIEF DESCRIPTION OF THE DRAWING A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: FIG. 1 is a schematic cross-sectional view of a rechargeable lithium battery according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings. When a lithium battery is charged at a temperature of more than 25° C., positive and negative electrodes are thermally instable so that an electrolyte salt, an organic solvent, and active materials of positive and negative electrodes may decompose and thereby cell cycle-life and safety may deteriorate. In order to solve the above problems, a surface-treated positive active material and an optimal combinatorial lithium salt are used to provide a rechargeable lithium battery having excellent cycle-life characteristics and safety even when using a positive electrode with a high active mass density. FIG. 1 is a schematic cross-sectional view of a rechargeable lithium battery according to one embodiment of the present invention. The rechargeable lithium battery 1 is mainly constructed of a negative electrode 2, a positive electrode 3, a separator 4 interposed between the positive electrode 3 and the negative electrode 2, and an electrolyte in which the separator 4 is immersed, in addition to a cell case 5 and a sealing member 6 that seals the cell case 5. The positive electrode 3 includes a current collector and the positive active material layer disposed on the current collector. The positive active material layer includes a positive active material including a core and a surface-treatment layer disposed on the surface of the core. The core may be formed of a material (which is also referred to as “core material”) including at least one of a compound represented by Formula 1 and a compound represented by Formula 2 that are electrochemically reduced or oxidized. LiaNibCocMndMeO2 Formula 1 In the above Formula 1, M is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 0.95≦a≦1.1, 0≦b≦0.999, 0≦c≦0.999, 0≦d≦0.999, and 0.001≦e≦0.2. LihMn2MiO4 Formula 2 In the above Formula 2, M is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 0.95≦h≦1.1 and 0.001≦i≦0.2. The Groups 13 and 14 respectively refer to Al-containing group and Si-containing group according to the new IUPAC system in the periodic table. The compounds of the above Formulas 1 and 2 lithium oxide doped with an element M. The element M may be selected from the group consisting of Mg, Ca, Sr, Ba, Ra Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, In, Ti, Si, Ge, Sn, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof. According to one embodiment, the element M may be selected from the group consisting of Mg, Ti, Al, and combinations thereof. In the Formulae 1 and 2, a, b, c, d, e, h, and i denote mol % of each element in the compound, respectively. When the amounts of Li, Ni, Co, Mn, and M existing in the compound included in the core material is out of these ranges, the electrochemical characteristics and thermal stability in terms of high efficiency are not improved. According to an embodiment, in the compound of Formula 1, the amount of Li may range from 0.96 to 1.05 mol %, and the amount of M may range from 0.005 to 0.1 mol %. In the compound of Formula 2, the amount of Li may range from 0.97 to 1.05 mol %, and the amount of M may range from 0.005 to 0.1 mol %. A core material including the compound represented by one of Formulas 1 and 2 may have an average particle diameter of 0.1 to 100 μm, and more specifically from 1 to 50 μm. When the average diameter of the core material is less than 0.1 μm, the active mass density is decreased, which is not desirable. When the average diameter of the core material exceeds 100 μm, the capacity deteriorates, which is also not desirable. A surface treatment layer including the compound of the following Formula 3 is present on the surface of the core material. M′xPyOz Formula 3 In the above Formula 3, M′ is selected from the group consisting of an alkali metal, an alkaline-earth metal, a Group 13 element, a Group 14 element, a transition element, a rare earth element, and combinations thereof, and 1≦x≦4, 0≦y≦7 and 2≦z≦30. The element M′ may be selected from the group consisting of Mg, Ca, Sr, Ba, Ra Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, In, Ti, Si, Ge, Sn, P, As, Sb, Bi, S, Se, Te, Po, and combinations thereof. According to one embodiment, the element M′ may be selected from the group consisting of Mg, Al, and combinations thereof. The surface-treatment layer includes a compound selected from the group consisting of Mg2P2O7, Al2O3, AlPO4, and combinations thereof. The amount of the compound of the above Formula 3 is more than or equal to 0.001 wt % and less than 20 wt % based on the total weight of the positive active material. According to another embodiment, the amount of the compound of the above Formula 3 ranges from 0.005 wt % to 10 wt % based on the total weight of the positive active material. When the amount of the compound of the Formula 3 is less than 0.001 wt %, the coating effect hardly appears, which is not desirable. When the amount is more than 20 wt %, the capacity deteriorates, which is also not desirable. The positive active material including the surface treatment layer has excellent structural stability, it maintains the same average voltage band at high efficiency and low efficiency, and has excellent cycle-life and capacity characteristics. Also, the excellent thermal stability prevents short-circuit or battery explosion even when the battery is exposed to heat and over-charged. In addition, the surface treatment layer prevents the positive active material from directly contacting the electrolyte solution so that a side reaction between the positive active material and the electrolyte solution may be prevented. As a result, it is possible to prevent deterioration in thermal stability and cycle-life of the rechargeable lithium battery, which is caused by the side reaction between the positive active material and the electrolyte solution that may occur at a high voltage of 4.2 to 4.5V. The positive active material layer including the positive active material may further include a binder for improving adherence between the positive active material layer and a current collector, or a conductive agent for improving electrical conductivity. The binder may be selected from the group consisting of polyvinylchloride, polyvinyldifluoride, an ethylene, an oxide-containing polymer, polyvinylalcohol, carboxylated polyvinylchloride, polyvinylidenefluoride, polyimide, polyurethane, an epoxy resin, nylon, carboxylmethyl cellulose, hydroxypropylene cellulose, diacetylene cellulose, polyvinyl pyrrolidone, polytetrafluoroethylene, a styrene-butadiene rubber, acrylated styrene-butadiene rubber, copolymers thereof, and combinations thereof. Any electrically conductive material can be used as a conductive agent unless it causes a chemical change. Examples of the conductive agent include natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, a metal powder, or a metal fiber including copper, nickel, aluminum, silver, and so on, or a polyphenylene derivative thereof. The positive electrode according to an embodiment of the present invention can be fabricated as follows. A positive active material composition is prepared by mixing a positive active material, a binder, and optionally a conductive agent, and then the composition is applied on a positive current collector followed by drying and compression. The positive electrode manufacturing method is well known, and thus it is not described in detail in the present specification. The positive active material, the binder, and the conductive agent are the same as above-described. The solvent used can be N-methylpyrrolidone, but it is not limited thereto. The current collector may be selected from the group consisting of aluminum foil, nickel foil, stainless steel foil, titanium foil, nickel foam, aluminum foam, a polymer substrate coated with a conductive metal, and combinations thereof. According to one embodiment, aluminum foil may be appropriate. The positive active material composition may be applied on the positive current collector by screen printing, spray coating, a coating method with a doctor blade, gravure coating, dip coating, silk screening, painting, or slot die coating, depending on the viscosity of the composition, but it is not limited thereto. According to one embodiment, screen printing may be suitably used. Also, the active mass density of the positive electrode 2 may be adjusted in the fabrication of the positive electrode 2 by controlling the pressure, frequency number, and temperature during compression. The compressing pressure, the compressing frequency number, and the compressing temperature are not specifically limited. However, they may be adjusted such that the fabricated positive electrode may have an active mass density of over 3.65 g/cc, and more specifically from 3.7 to 4.2 g/cc. The active mass density of an electrode is a value obtained by dividing the mass of the components (e.g., active material, conductive agent, and binder) excluding the current collector in the electrode by the volume. The unit of active mass density is g/cc. Generally, the higher the active mass density of an electrode becomes, the better the battery capacity becomes. However, there is problem in that as the cycle-life characteristic deteriorates, the active mass density increases. For this reason, the active mass density of a positive electrode used in a generally-used rechargeable lithium battery is about 3.6 g/cc. However, the positive electrode of the rechargeable lithium battery suggested in the embodiment of the present invention has a high active mass density and excellent capacity characteristics and cycle-life characteristics. The negative electrode 3 includes a current collector and a negative active material layer disposed on the current collector. The negative active material layer includes electrochemical redox materials such as a negative active material than can reversibly intercalate and deintercalate lithium ions. The negative active material may include at least one selected from the group consisting of lithium, a metal being capable of alloying with lithium, a carbonaceous material, a composite material including the metal and carbonaceous material, and combinations thereof. The metal being capable of alloying with lithium may be Al, Si, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Ag, Ge, or Ti. The carbonaceous material may include artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbeads, fullerene, amorphous carbon, and so on. The amorphous carbon may be a soft carbon (carbon obtained by firing at a low temperature) or a hard carbon (carbon obtained by firing at a high temperature), and the crystalline carbon may be sheet-shaped, spherically-shaped, or fiber-shaped natural graphite or artificial graphite. The carbonaceous material has an Lc (crystallite size) of at least 20 nm found through X-ray diffraction. According to one embodiment, the carbonaceous material has an Lc (crystallite size) of 50 to 1000 nm found through X-ray diffraction. According to one embodiment, the crystalline carbonaceous material may be more suitable than the amorphous carbonaceous material. The carbonaceous material exhibits an exothermic peak at 700° C. or more. The carbonaceous material may be a carbon material prepared by carbonizing mesophase spherical particles and graphitizing the carbonized material, or a graphite fiber prepared by carbonizing and graphitizing a mesophase pitch fiber. The active material layer of the negative electrode 3 may further include a binder for improving adherence between the negative active material layer and a current collector, or a conductive agent for improving electrical conductivity as in the positive electrode 2. The binder and the conductive agent may be the same as described above. The negative electrode 3 can be fabricated as follows. A negative active material composition is prepared by mixing a negative active material, a binder, and optionally a conductive agent, and then the composition is applied on a negative current collector such as copper. The negative electrode manufacturing method is well known, and thus it is not described in detail in the present specification. The solvent used can be N-methylpyrrolidone, but it is not limited thereto. The current collector may be copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, or combinations thereof. According to one embodiment, copper foil may be appropriate. In the rechargeable battery according to one embodiment of the present invention, the electrolyte includes a non-aqueous organic solvent and a lithium salt. The lithium salts act as a lithium ion source, which facilitates the basic battery operation. According to one embodiment of the present invention, the lithium salt includes lithium hexafluorophosphate (LiPF6) and a lithium imide-based compound. The lithium imide-based compound is represented by the following Formula 4. LiN(CpF2p+1SO2)r(CqF2q+1SO2)s Formula 4 In the above Formula 4, 1≦p, 1≦q, 0≦r≦3, and 0≦s≦3. The lithium imide-based compound may be selected from the group consisting of LiN(CF3SO2)2, LiN(C2F5SO2)2, and a mixture thereof. The LiPF6 and lithium imide-based compounds have previously been individually used as lithium ion sources in electrolytes of a rechargeable lithium battery. However, the rechargeable lithium battery suggested in the embodiment of the present invention uses a lithium salt that combines the above two components so that the deterioration of the cycle-life characteristic caused by using a positive electrode of a high active mass density can be prevented. LiPF6 and a lithium imide-based compound are used in a weight ratio of 99.9:0.1 to 50:50. According to another embodiment, LiPF6 and a lithium imide-based compound are used in a weight ratio of 96.7:3.3 to 56.7:43.3. When the amount of the lithium imide-based compound exceeds 50 wt % with respect to the LiPF6 in the total weight of lithium salt, the capacity is reduced, which is not desirable. When the amount of LiPF6 with respect to the lithium imide-based compound exceeds the range, the performance at a high temperature is reduced, which is not desirable. The lithium salt that includes the LiPF6 and the lithium imide-based compound at the optimal combination ratio may be included in the electrolyte at a concentration of 0.1 to 2.0M, and more specifically at a concentration of 0.5 to 1.8M. When the concentration of the lithium salt is lower than 0.1 M, the battery does not adequately perform, which is not desirable. When it exceeds 2.0M, the performance at a high temperature deteriorates, which is also not desirable. According to one embodiment of the present invention, the electrolyte may further include a conventional lithium salt as a lithium ion source. Examples of the conventional lithium salt may include LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, LiC4F9SO3, LiAlO4, LiAlCl4, LiSO3CF3, LiCl, Lil, LiB(C2O4)2, or a mixture thereof. The additional lithium salt may be added in an appropriate amount. According to an embodiment, the LiBF4 may be included at 0.01 to 2 parts by weight with respect to 100 parts by weight of LiPF6, and more specifically at 0.05 to 1 part by weight. When the amount of LiBF4 with respect to LiPF6 is less than 0.01 parts by weight, the battery performance may deteriorate, which is not desirable. When it exceeds 2 parts by weight, the cycle-life characteristic may deteriorate, which is also not desirable. The non-aqueous organic solvent acts as a medium for transmitting ions taking part in the electrochemical reaction of the battery. The non-aqueous organic solvent may include a carbonate-based, ester-based, ether-based, ketone-based, alcohol-based, or aprotic solvent. Examples of the carbonate-based solvent may include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC), ethylmethyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and so on. Examples of the ester-based solvent may include n-methyl acetate, n-ethyl acetate, n-propyl acetate, dimethylacetate, methylpropionate, ethylpropionate, γ-butyrolactone, decanolide, valerolactone, mevalonolactone, caprolactone, and so on. Examples of the ether-based solvent include dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, tetrahydrofuran, and so on. Examples of the ketone-based solvent include cyclohexanone, and so on. Examples of the alcohol-based solvent include ethanol, isopropyl alcohol, and so on. Examples of the aprotic solvent include nitrites such as X—CN (wherein X is a C2 to C50 linear, branched, or cyclic hydrocarbon, a double bond, an aromatic ring, or an ether bond), amides such as dimethylformamide, and dioxolanes such as 1,3-dioxolane, sulfolane, and so on. The non-aqueous organic solvent may be used singularly or in mixture composed of two or more solvents. When the organic solvent is used in a mixture, the mixture ratio can be controlled in accordance with desired battery performance. The carbonate-based solvent may include a mixture of a cyclic carbonate and a linear carbonate. When the cyclic carbonate and the chain carbonate are mixed together in a volume ratio of 1:1 to 1:9, and the mixture is used as an electrolyte, the electrolyte performance may be enhanced. In addition, the electrolyte of the present invention may further include mixtures of carbonate-based solvents and aromatic hydrocarbon-based solvents. The carbonate-based solvents and the aromatic hydrocarbon-based solvents are preferably mixed together in a volume ratio of 1:1 to 30:1. The aromatic hydrocarbon-based organic solvent may be represented by the following Formula 5. In the above Formula 5, R1 to R6 are independently selected from the group consisting of hydrogen, a halogen, a C1 to C10 alkyl, a haloalkyl, and combinations thereof. The aromatic hydrocarbon-based organic solvent may include, but is not limited to, at least one selected from the group consisting of benzene, fluorobenzene, 1,2-difluorobenzene, 1,3-difluorobenzene, 1,4-difluorobenzene, 1,2,3-trifluorobenzene, 1,2,4-trifluorobenzene, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, iodobenzene, 1,2-diiodobenzene, 1,3-diiodobenzene, 1,4-diiodobenzene, 1,2,3-triiodobenzene, 1,2,4-triiodobenzene, toluene, fluorotoluene, 1,2-difluorotoluene, 1,3-difluorotoluene, 1,4-difluorotoluene, 1,2,3-trifluorotoluene, 1,2,4-trifluorotoluene, chlorotoluene, 1,2-dichlorotoluene, 1,3-dichlorotoluene, 1,4-dichlorotoluene, 1,2,3-trichlorotoluene, 1,2,4-trichlorotoluene, iodotoluene, 1,2-diiodotoluene, 1,3-diiodotoluene, 1,4-diiodotoluene, 1,2,3-triiodotoluene, 1,2,4-triiodotoluene, xylene, and combinations thereof. The electrolyte may further include an additive to improve battery characteristics. According to one embodiment of the present invention, the electrolyte may further include an ethylene carbonate-based additive represented by the following Formula 6 to improve safety of a rechargeable lithium battery. In the above Formula 6, X and Y are independently selected from the group consisting of hydrogen, a halogen, a cyano (CN), a nitro (NO2), and a C1 to C5 fluorinated alkyl, and at least one of X and Y is selected from the group consisting of a halogen, a cyano (CN), a nitro (NO2), and a C1 to C5 fluorinated alkyl. According to one embodiment, the ethylene carbonate-based compound additive includes at least one selected from the group consisting of ethylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, chloroethylene carbonate, dichloroethylene carbonate, bromoethylene carbonate, dibromoethylene carbonate, nitroethylene carbonate, cyanoethylene carbonate, and combinations thereof. According to another embodiment, fluoroethylene carbonate may be appropriate. The amount of the ethylene carbonate-based compound additive may be controlled considering thermal stability of the electrolyte, but is not limited to a specific range. The electrolyte having the above-composition can improve cycle-life characteristics at normal and high temperatures by including a mixture of LiPF6 and a lithium imide-based compound as a lithium salt, even when using a positive electrode having a high active mass density. The rechargeable lithium battery generally includes a positive electrode, a negative electrode, and an electrolyte. The battery may further include a separator as needed. The separator may include any material used in conventional lithium secondary batteries. Non-limiting examples of suitable separator materials include polyethylene, polypropylene, polyvinylidene fluoride, and multilayers thereof such as a polyethylene/polypropylene bilayered separator, a polyethylene/polypropylene/polyethylene three-layered separator, or a polypropylene/polyethylene/polypropylene three-layered separator. The rechargeable lithium battery having the above constitution exhibits a charge voltage of more than or equal to 4.3V. According to one embodiment, the battery exhibits a charge voltage ranging from 4.3 to 4.5V. When the rechargeable lithium battery has a charge voltage of less than 4.3V, a high-capacity battery cannot be realized. The rechargeable lithium batteries can be power sources for many types of electrical devices, for example portable telephones, cellular phones, game machines, portable televisions, laptop computers, calculators, etc. However, lithium batteries are not limited to these uses. The following examples illustrate the present invention in more detail. These examples, however, should not in any sense be interpreted as limiting the scope of the present invention. Battery Cell Performance Evaluation Depending on the Surface-Treated Positive Active Material and a Composition Ratio of a Lithium Salt EXAMPLE 1-1 A mixture was prepared by mixing CO3O4, Li2CO3, and Mg(OH)2 in water at a molar ratio of 1/3:1/2:1/50. The mixture was dried at 110° C. for 4 hours, and then underwent heat treatment again at 400° C. for 8 hours to prepare a core formed of LiCo0.98Mg0.02O2 having an average particle diameter of 13 μm. 20 g of the LiCo0.98Mg0.02O2 core material having an average particle diameter of 13 μm was added to 10 Ml of a 0.1 wt % Mg2P2O7 solution, mixed, and dried at 130° C. for 30 minutes. The dried powder underwent heat treatment at 400° C. for 5 hours to prepare a positive active material including a surface treatment layer including a Mg2P2O7 compound on the surface of LiCo0.98Mg0.02O2. The above prepared positive active material, polyvinylidene fluoride (PVDF) as a binder, and carbon (Super-P) as a conductive agent were dispersed and mixed in N-methyl-2-pyrrolidone at a weight ratio of 96:2:2 to prepare a composition for forming a positive active material layer. The composition for forming a positive active material layer was applied to aluminum foil, dried, and compressed to prepare a positive electrode having an active mass density of 3.73 g/cc. A composition for forming a negative active material layer was prepared by mixing carbon as a negative active material and PVDF as a binder at a weight ratio of 94:6, and dispersing the mixture in N-methyl-2-pyrrolidone. The composition was applied to copper foil, dried, and compressed to fabricate a negative electrode. A polyethylene separator was interposed between the fabricated electrodes. They were spirally wound and compressed, and then an electrolyte was injected to fabricate a 18650 cylindrical battery. A mixed salt of 1.1M LiPF6 and 0.4M LiN(CF3SO2)2 dissolved in a mixture of a non-aqueous organic solvent of ethylene carbonate/ethylmethyl carbonate/dimethyl carbonate (EC/EMC/DMC) in a volume ratio of 3/3/4 was used for an electrolyte. EXAMPLES 1-2 to 1-45 AND COMPARATIVE EXAMPLES 1 to 7 A rechargeable lithium battery was fabricated by the same method as in Example 1-1, except that the kinds of the doping element M and the surface treatment compound and the amounts of LiPF6 and LiN(CF3SO2)2 in the core material of the positive active material were diversely changed as shown in the following Tables 1a to 1c. The rechargeable lithium battery cells fabricated according to Examples 1-1 to 1-45 and Comparative Examples 1 to 7 were charged at 0.2C and discharged at 0.2C once (formation process) and then charged at 0.5C and discharged at 0.2C once (standard process). The cycle-life characteristics of the battery cells were estimated after the battery cells were charged at 1.0C and discharged at 1.0C 300 times at 60° C. Then their storage characteristics were estimated by standing the lithium rechargeable battery cells at 60° C. for two weeks and measuring their open circuit voltage (OCV). The results are presented in the following Tables 1a to 1c. TABLE 1a Doping Element, M Surface (doping treatment Cycle Storage amount compound LiPF6 LiN(CF3SO2)2 life characteristics 2 mol %) Core material (0.1 wt %) (M) (M) (%) (V) Comp. — LiCoO2 — 1.5 — 35 4.06 Ex. 1 Comp. Mg LiCo0.98Mg0.02O2 — 1.5 — 41 4.07 Ex. 2 Comp. Mg LiCo0.98Mg0.02O2 — 1.0 0.5 65 4.10 Ex. 3 Comp. — LiCoO2 Mg2P2O7 1.5 — 52 4.08 Ex. 4 Comp. — LiCoO2 Mg2P2O7 1.0 0.5 62 4.09 Ex. 5 Comp. — LiCoO2 — 1.0 0.5 67 4.15 Ex. 6 Comp. Mg LiCo0.98Mg0.02O2 Mg2P2O7 1.5 — 71 4.13 Ex. 7 Ex. 1-1 Mg LiCo0.98Mg0.02O2 Mg2P2O7 1.0 0.5 84 4.29 Ex. 1-2 Mg LiCo0.98Mg0.02O2 Mg2P2O7 1.1 0.4 82 4.27 Ex. 1-3 Mg LiCo0.98Mg0.02O2 Mg2P2O7 1.2 0.3 81 4.26 Ex. 1-4 Mg LiCo0.98Mg0.02O2 Mg2P2O7 1.3 0.2 80 4.24 Ex. 1-5 Mg LiCo0.98Mg0.02O2 Mg2P2O7 1.4 0.1 79 4.21 Ex. 1-6 Mg LiCo0.98Mg0.02O2 Al2O3 1.0 0.5 83 4.34 Ex. 1-7 Mg LiCo0.98Mg0.02O2 Al2O3 1.1 0.4 84 4.32 Ex. 1-8 Mg LiCo0.98Mg0.02O2 Al2O3 1.2 0.3 81 4.31 Ex. 1-9 Mg LiCo0.98Mg0.02O2 Al2O3 1.3 0.2 83 4.30 Ex. 1- Mg LiCo0.98Mg0.02O2 Al2O3 1.4 0.1 80 4.26 10 Ex. 1- Mg LiCo0.98Mg0.02O2 AlPO4 1.0 0.5 82 4.28 11 Ex. 1- Mg LiCo0.98Mg0.02O2 AlPO4 1.1 0.4 81 4.26 12 Ex. 1- Mg LiCo0.98Mg0.02O2 AlPO4 1.2 0.3 81 4.25 13 Ex. 1- Mg LiCo0.98Mg0.02O2 AlPO4 1.3 0.2 79 4.23 14 Ex. 1- Mg LiCo0.98Mg0.02O2 AlPO4 1.4 0.1 77 4.20 15 TABLE 1b Doping element, Surface M (doping treatment Cycle- Storage amount: compound LiPF6 LiN(CF3SO2)2 life Characteristics 2 mol % Core material (0.1 wt %) (M) (M) (%) (V) Ex. 1-16 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.0 0.5 81 4.26 Ex. 1-17 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.1 0.4 80 4.24 Ex. 1-18 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.2 0.3 79 4.23 Ex. 1-19 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.3 0.2 78 4.21 Ex. 1-20 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.4 0.1 77 4.18 Ex. 1-21 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.0 0.5 84 4.28 Ex. 1-22 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.1 0.4 82 4.26 Ex. 1-23 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.2 0.3 81 4.25 Ex. 1-24 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.3 0.2 80 4.23 Ex. 1-25 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.4 0.1 78 4.20 Ex. 1-26 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.0 0.5 80 4.25 Ex. 1-27 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.1 0.4 79 4.23 Ex. 1-28 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.2 0.3 78 4.22 Ex. 1-29 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.3 0.2 77 4.20 Ex. 1-30 Mg + Ti LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.4 0.1 75 4.17 TABLE 1c Surface Doping Treatment Cycle Storage Element, M compound LiPF6 LiN(CF3SO2)2 life characteristics (2 mol %) Core material (0.1 wt %) (M) (M) (%) (V) Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.0 0.5 82 4.28 31 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.1 0.4 81 4.26 32 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.2 0.3 80 4.25 33 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.3 0.2 80 4.23 34 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Mg2P2O7 1.4 0.1 77 4.20 35 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.0 0.5 79 4.30 36 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.1 0.4 78 4.28 37 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.2 0.3 77 4.27 38 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.3 0.2 76 4.25 39 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 Al2O3 1.4 0.1 74 4.22 40 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.0 0.5 76 4.27 41 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.1 0.4 75 4.25 42 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.2 0.3 73 4.24 43 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.3 0.2 72 4.22 44 Ex. 1- Mg + Al LiCo0.98Mg0.01Ti0.01O2 AlPO4 1.4 0.1 71 4.19 45 According to the above Tables 1a to 1c, the lithium rechargeable battery cells of Examples 1-1 to 1-45 that use the positive active material having the surface treatment layer and the electrolyte including both LiPF6 salt and the lithium imide compound showed excellent cycle-life characteristics and storage characteristics at a high temperature, compared to the rechargeable lithium battery cells of Comparative Example 1-7 whose battery formation conditions and amount conditions are out of the range suggested in the embodiments of the present invention. Battery Cell Performance Evaluation Depending on Composition Ratio of a Lithium Salt EXAMPLE 2-1 A mixture was prepared by mixing CO3O4, Li2CO3, and Mg(OH)2 in water at a molar ratio of 1/3:1/2:1/50. The mixture was dried at 110° C. for 4 hours and then underwent heat treatment again at 400° C. for 8 hours to prepare a core formed of LiCo0.98Mg0.02O2 having an average particle diameter of 13 μm. 20 g of the LiCo0.98Mg0.02O2 core material having an average particle diameter of 13 μm was added to 10 Ml of a 0.1 wt % Mg2P2O7 solution, mixed, and dried at 130° C. for 30 minutes. The dried powder underwent heat treatment at 400° C. for 5 hours to prepare a positive active material including a surface treatment layer containing the Mg2P2O7 compound on the surface of LiCo0.98Mg0.02O2. A composition for forming a positive active material layer was prepared by dispersing and mixing the above prepared positive active material, polyvinylidene fluoride (PVDF) as a binder, and carbon (Super-P) as a conductive agent in N-methyl-2-pyrrolidone in a weight ratio of 96:2:2. The composition for forming a positive active material layer was applied to aluminum foil, dried, and compressed to fabricate a positive electrode having an active mass density of 3.73 g/cc. A composition for forming a negative active material layer was prepared by mixing carbon as a negative active material and PVDF as a binder at a weight ratio of 94:6, and dispersing the mixture in N-methyl-2-pyrrolidone. The composition was applied to copper foil, dried, and compressed to prepare a negative electrode. A polyethylene separator was interposed between the fabricated electrodes, spirally wound, compressed, and then an electrolyte was injected to fabricate a 18650 cylindrical battery. A mixed salt of 1.3M LiPF6 and 0.5M LiN(CF3SO2)2 dissolved in a mixture of a non-aqueous organic solvent of ethylene carbonate/ethylmethyl carbonate/dimethyl carbonate (EC/EMC/DMC) in a volume ratio of 3/3/4 was used for an electrolyte. EXAMPLES 2-2 to 2-17 A rechargeable lithium battery cell was fabricated in the same method as in Example 2-1, except that the amount of LiN(CF3SO2)2 to be added was diversely changed as shown in the following Table 2. The cell characteristics of the rechargeable lithium battery cells fabricated according to Example 2-1 to 2-17 were measured in the same method as the previously performed “Battery cell performance evaluation depending on the surface-treated positive active material and a composition ratio of a lithium salt.” The results are shown in the following Table 2. TABLE 2 LiPF6:LiN(CF3SO2)2 composition ratio Cycle life Storage (weight ratio) (%) Characteristics (V) Comp. Ex. 7 100:0 71 4.13 Ex. 2-1 99.9:0.1 74 4.18 Ex. 2-2 96.7:3.3 75 4.19 Ex. 2-3 93.3:6.7 79 4.21 Ex. 2-4 90.0:10.0 79 4.23 Ex. 2-5 86.7:13.3 80 4.24 Ex. 2-6 83.3:16.7 81 4.25 Ex. 2-7 80.0:20.0 81 4.26 Ex. 2-8 76.7:23.3 81 4.26 Ex. 2-9 73.3:26.7 82 4.27 Ex. 2-10 70.0:30.0 83 4.27 Ex. 2-11 66.7:33.3 84 4.29 Ex. 2-12 63.3:36.7 82 4.28 Ex. 2-13 60.0:40.0 80 4.26 Ex. 2-14 56.7:43.3 78 4.21 Ex. 2-15 53.3:46.7 75 4.20 Ex. 2-16 50.0:50.0 72 4.18 Ex. 2-17 46.7:53.3 65 4.16 As shown in the Table 2, the rechargeable lithium battery cells of Examples 2-1 to 2-16 that included both LiPF6 and LiN(CF3SO2)2 showed better cycle-life and storage characteristics than the rechargeable lithium battery cell of Comparative Example 7 that included only LiPF6. The rechargeable lithium battery cell of Example 2-17 showed a lower cycle-life characteristic but a better storage characteristic than the rechargeable lithium battery cell of Comparative Example 7. Particularly, the rechargeable lithium battery cells of Examples 2-1 to 2-16 that included LiPF6 and LiN(CF3SO2)2 at a ratio of 99.9:0.1 to 50:50 showed better performance than the rechargeable lithium battery cell of Example 2-17. Thus, it was proven that the above ratio of LiPF6 to LiN(CF3SO2)2 is the optimal composition ratio. Battery Cell Performance Evaluation Depending on a Loading Amount of Surface Treatment Compound EXAMPLE 3-1 A mixture was prepared by mixing CO3O4, Li2CO3 and Mg(OH)2 in water at a molar ratio of 1/3:1/2:1/50. The mixture was dried at 110° C. for 4 hours, and then underwent heat treatment again at 400° C. for 8 hours to prepare a core formed of LiCo0.98Mg0.02O2 having an average particle diameter of 13 μm. 20 g of the LiCo0.98Mg0.02O2 core material having an average particle diameter of 13 μm was added to 10 Ml of a 0.001 wt % Mg2P2O7 solution, mixed, and dried at 130° C. for 30 minutes. The dried powder underwent heat treatment at 400° C. for 5 hours to prepare a positive active material including a surface treatment layer including a Mg2P2O7 compound on the surface of LiCo0.98Mg0.02O2. The above-prepared positive active material, polyvinylidene fluoride (PVDF) as a binder, and carbon (Super-P) as a conductive agent were dispersed and mixed in N-methyl-2-pyrrolidone at a weight ratio of 96:2:2 to prepare a composition for forming a positive active material layer. The composition for forming a positive active material layer was applied to aluminum foil, dried, and compressed to prepare a positive electrode having an active mass density of 3.73 g/cc. A composition for forming a negative active material layer was prepared by mixing carbon as a negative active material and PVDF as a binder at a weight ratio of 94:6, and dispersing the mixture in N-methyl-2-pyrrolidone. The composition was applied to copper foil, dried, and compressed to prepare a negative electrode. A polyethylene separator was interposed between the fabricated electrodes, spirally wound, compressed, and then an electrolyte was injected to fabricate a 18650 cylindrical battery. A mixed salt of 1.1 M LiPF6 and 0.4M LiN(CF3SO2)2 dissolved in a mixture of a non-aqueous organic solvent of ethylene carbonate/ethylmethyl carbonate/dimethyl carbonate (EC/EMC/DMC) in a volume ratio of 3/3/4 was used for an electrolyte. EXAMPLES 3-2 To 3-10 Rechargeable lithium battery cells were fabricated by the same method as in Example 3-1, except that the loading amount of the surface treatment compound on the core material of the positive active material was diversely changed and added. The cell characteristics of the rechargeable lithium battery cells fabricated according to Examples 3-1 to 3-10 were measured in the same method as the previously performed “Battery cell performance evaluation depending on the surface-treated positive active material and a composition ratio of a lithium salt.” The results are shown in the following Table 3. TABLE 3 Storage Coating amount of characteristics Mg2P2O7 (wt %) Cycle life (%) (V) Comp. Ex. 3 0 65 4.10 Ex. 3-1 0.001 72 4.19 Ex. 3-2 0.01 76 4.21 Ex. 3-3 0.05 79 4.23 Ex. 3-4 0.1 82 4.27 Ex. 3-5 0.5 81 4.28 Ex. 3-6 1 80 4.24 Ex. 3-7 2 79 4.23 Ex. 3-8 5 77 4.21 Ex. 3-9 10 73 4.17 Ex. 3-10 20 67 4.08 According to Table 3, the rechargeable lithium battery cells of Examples 3-1 to 3-9 that included a positive active material with a surface treatment layer showed much better cycle-life and storage characteristics than the rechargeable lithium battery cell of Comparative Example 3 that included a positive active material without a surface treatment layer. The rechargeable lithium battery cell of Example 3-10 showed a lower storage characteristic but a better cycle-life characteristic than the rechargeable lithium battery cell of Comparative Example 3. Particularly, the rechargeable lithium battery cells of Examples 3-1 to 3-9 where the loading amounts of the surface treatment compound in the surface treatment layer were 0.001 to 10 wt % with respect to the total weight of the active material showed much better characteristics than Example 3-10 and Comparative Example 3. Thus, it was proven that the range of the above loading amount is the optimal range for the surface treatment compound. The rechargeable lithium battery fabricated according to the embodiment of the present invention has high-capacity and excellent cycle-life characteristic, and it particularly maintains the high-capacity and excellent cycle-life characteristic at a high voltage and in a high active mass density. While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
|
H
|
H01
|
H01M
|
4
|
40
|
|||
11695065
|
US20080143541A1-20080619
|
CIRCUIT FOR POWER INDICATOR
|
ACCEPTED
|
20080605
|
20080619
|
[]
|
G08B2118
|
["G08B2118"]
|
7567185
|
20070402
|
20090728
|
340
|
815450
|
57220.0
|
LE
|
TUNG
|
[{"inventor_name_last": "ZHANG", "inventor_name_first": "XIANG", "inventor_city": "Shenzhen", "inventor_state": "", "inventor_country": "CN"}]
|
A circuit for a power indicator, comprises an indicator (10), a power source (V1), a first MOSFET (20), a first controlling circuit (40), a second MOSFET (50), and a second controlling circuit (60). The indicator includes a positive terminal and a negative terminal. The power source is connected to the positive terminal of the indicator via a resistor (30). A drain of the first MOSFET is connected to the negative terminal of the indicator. The first controlling circuit transmits a controlling signal to a gate of the first MOSFET according to working statuses of a computer. A drain of the second MOSFET is connected to a source of the first MOSFET and a source of the second MOSFET is connected to ground. The second controlling circuit transmits a controlling signal to a gate of the second MOSFET.
|
1. A circuit for a power indicator, comprising: an indicator comprising a positive terminal and a negative terminal; a power source connected to the positive terminal of the indicator via a resistor; a first MOSFET comprising a drain connected to the negative terminal of the indicator; a first controlling circuit for transmitting a controlling signal responsive to working statuses of a computer to a gate of the first MOSFET; a second MOSFET comprising a drain connected to a source of the first MOSFET, and a source connected to ground; and a second controlling circuit for transmitting a controlling signal to a gate of the second MOSFET; wherein when the computer is powered on or off, the second controlling circuit transmits the controlling signal to turn on or off the second MOSFET respectively. 2. The circuit as described in claim 1, wherein the second MOSFET is an N-channel MOSFET. 3. The circuit as described in claim 2, wherein the second controlling circuit is a power controlling circuit, when the computer is powered on or off, the power controlling circuit transmits a high or low level controlling signal to the gate of the N-channel MOSFET to thereby turn on or off the second MOSFET respectively. 4. The circuit as described in claim 1, wherein the indicator is a light emitting diode. 5. The circuit as described in claim 1, wherein the first MOSFET is a P-channel MOSFET. 6. A circuit for a power indicator in a computer, comprising: an indicator comprising a positive terminal and a negative terminal; a power source connected to the positive terminal of the indicator via a resistor; a first MOSFET comprising a drain connected to the negative terminal of the indicator and a gate for receiving a first controlling signal responsive to working statuses of the computer; and a second MOSFET comprising a drain connected to a source of the first MOSFET, a source connected to ground and a gate for receiving a second controlling signal; wherein when the computer is powered on or off, the second MOSFET receives the second controlling signal to be turned on or off respectively. 7. The circuit as described in claim 6, wherein the second MOSFET is an N-channel MOSFET. 8. The circuit as described in claim 6, wherein the first MOSFET is a P-channel MOSFET. 9. The circuit as described in claim 6, wherein the indicator is a light emitting diode. 10. A circuit for a power indicator in a computer, comprising: an indicator comprising a first terminal electrically connected to a power source and a second terminal; a first electric switch and a second electric switch connecting the second terminal of the indicator to ground in series; a first controlling circuit for transmitting a first controlling signal responsive to working statuses of the computer to the first electric switch; and a second controlling circuit for transmitting a second controlling signal responsive to on or off of the computer to the second electric switch; wherein when the computer is powered on, the second electric switch is turned on and the first electric switch is selectively turned on or off according to the working statuses of the computer to thereby allow the indicator showing the corresponding working statuses of the computer, and when the computer is powered off, the second electric switch is turned off which results in the indicator being turn off. 11. The circuit as described in claim 10, wherein the first electronic switch and the second electronic switch are field effect transistors (FETs). 12. The circuit as described in claim 11, wherein the first FET has a drain connected to the second terminal of the indicator, a gate connected to the first controlling circuit and a source connected to a drain of the second FET. 13. The circuit as described in claim 12, wherein the second FET has a gate connected to the second controlling circuit and a source connected to ground. 14. The circuit as described in claim 12, wherein the first FET is a P-channel metal oxide semiconductor FET. 15. The circuit as described in claim 13, wherein the second FET is an N-channel metal oxide semiconductor FET. 16. The circuit as described in claim 10, wherein the indicator is a light emitting diode.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to circuits for power indicators, and more particularly to a circuit for a power indicator in a computer. 2. Description of Related Art A computer system is composed of hardware and software. The hardware typically includes a motherboard, an optical disk drive, a hard disk drive, a memory, a network card, and so on. When the computer system is running, it is necessary to know working statuses of the hardware. So, indicator lights are used to show the working statues of the hardware, and corresponding drive circuits for driving these indicator lights are combined in the computer system. Referring to FIG. 1 , a typical circuit for a power indicator includes a light emitting diode 10 ′, a P-channel MOSFET (metal oxide semiconductor field effect transistor) 20 ′, a resistor 30 ′, and a controlling circuit 40 ′. A positive terminal of the light emitting diode 10 ′ is connected to a power source V 0 via the resistor 30 ′ and a negative terminal of the light emitting diode 10 ′ is connected to a drain of the P-channel MOSFET 20 ′. The controlling circuit 40 ′ is connected to a gate of the P-channel MOSFET 20 ′. A source of the P-channel MOSFET 20 ′ is connected to a ground. According to working statuses of a computer, the controlling circuit 40 ′ sends a controlling signal S 0 to the gate of the P-channel MOSFET 20 ′. For example, when the hardware is writing data, the controlling circuit 40 ′ sends a controlling signal S 0 with high level to turn on the MOSFET 20 ′ so that the light emitting diode 10 ′ is turned on to thereby show the working statuses of writing data of the hardware. When the computer is on and working normally, the level of the controlling signal S 0 is set by the controlling circuit 40 ′ according to working statuses of the computer. The light emitting diode 10 ′ can correctly show the working statuses of the computer. However, when the computer is down and needs to be restarted or rebooted, the controlling circuit 40 ′ may send no controlling signal to enable the P-channel MOSFET 20 ′ to be turned off, and the light emitting diode 10 ′ may remain lit giving a false indication.
|
<SOH> SUMMARY OF THE INVENTION <EOH>A circuit for a power indicator comprises, an indicator, a power source, a first MOSFET, a first controlling circuit, a second MOSFET, and a second controlling circuit. The indicator includes a positive terminal and a negative terminal. The power source is connected to the positive terminal of the indicator via a resistor. A drain of the first MOSFET is connected to the negative terminal of the indicator. The first controlling circuit transmits a controlling signal to a gate of the first MOSFET according to working statuses of a computer. A drain of the second MOSFET is connected to a source of the first MOSFET and a source of the second MOSFET is connected to ground. The second controlling circuit transmits a controlling signal to a gate of the second MOSFET. Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings, in which:
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to circuits for power indicators, and more particularly to a circuit for a power indicator in a computer. 2. Description of Related Art A computer system is composed of hardware and software. The hardware typically includes a motherboard, an optical disk drive, a hard disk drive, a memory, a network card, and so on. When the computer system is running, it is necessary to know working statuses of the hardware. So, indicator lights are used to show the working statues of the hardware, and corresponding drive circuits for driving these indicator lights are combined in the computer system. Referring to FIG. 1, a typical circuit for a power indicator includes a light emitting diode 10′, a P-channel MOSFET (metal oxide semiconductor field effect transistor) 20′, a resistor 30′, and a controlling circuit 40′. A positive terminal of the light emitting diode 10′ is connected to a power source V0 via the resistor 30′ and a negative terminal of the light emitting diode 10′ is connected to a drain of the P-channel MOSFET 20′. The controlling circuit 40′ is connected to a gate of the P-channel MOSFET 20′. A source of the P-channel MOSFET 20′ is connected to a ground. According to working statuses of a computer, the controlling circuit 40′ sends a controlling signal S0 to the gate of the P-channel MOSFET 20′. For example, when the hardware is writing data, the controlling circuit 40′ sends a controlling signal S0 with high level to turn on the MOSFET 20′ so that the light emitting diode 10′ is turned on to thereby show the working statuses of writing data of the hardware. When the computer is on and working normally, the level of the controlling signal S0 is set by the controlling circuit 40′ according to working statuses of the computer. The light emitting diode 10′ can correctly show the working statuses of the computer. However, when the computer is down and needs to be restarted or rebooted, the controlling circuit 40′ may send no controlling signal to enable the P-channel MOSFET 20′ to be turned off, and the light emitting diode 10′ may remain lit giving a false indication. SUMMARY OF THE INVENTION A circuit for a power indicator comprises, an indicator, a power source, a first MOSFET, a first controlling circuit, a second MOSFET, and a second controlling circuit. The indicator includes a positive terminal and a negative terminal. The power source is connected to the positive terminal of the indicator via a resistor. A drain of the first MOSFET is connected to the negative terminal of the indicator. The first controlling circuit transmits a controlling signal to a gate of the first MOSFET according to working statuses of a computer. A drain of the second MOSFET is connected to a source of the first MOSFET and a source of the second MOSFET is connected to ground. The second controlling circuit transmits a controlling signal to a gate of the second MOSFET. Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a prior art circuit for a power indicator; and FIG. 2 is a diagram of a circuit for a power indicator in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 2, a circuit for a power indicator in accordance with a preferred embodiment of the present invention includes a power source V1, a light emitting diode 10, a P-channel MOSFET 20, a resistor 30, a first controlling circuit 40, an N-channel MOSFET 50, and a second controlling circuit 60. A positive terminal of the light emitting diode 10 is connected to the power source V1 via the resistor 30. A negative terminal of the light emitting diode 10 is connected to a drain of the P-channel MOSFET 20. The first controlling circuit 40 is connected to a gate of the P-channel MOSFET 20. A source of the P-channel MOSFET 20 is connected to a drain of the N-channel MOSFET 50. A gate of the N-channel MOSFET 50 is connected to the second controlling circuit 60. A source of the N-channel MOSFET 50 is connected to ground. Generally, the first controlling circuit 40 transmits a controlling signal S1 to the gate of the P-channel MOSFET 20 according to working statuses of the computer. When the computer is powered on or off, the second controlling circuit 60 transmits a high or low level controlling signal S2 to the gate of the N-channel MOSFET 50 respectively. In this embodiment, the second controlling circuit 60 is a power controlling circuit of the computer, when the computer is on, the power controlling circuit provides a high level signal to turn on the N-channel MOSFET 50; when the computer is powered off, the power controlling circuit provides a low level signal to turn off the N-channel MOSFET 50. When the computer is on and operating normally, the controlling signal S2 is high, which enables the N-channel MOSFET 50 to be turned on. The first controlling circuit 40 sends the controlling signal S1 to turn on or off the P-channel MOSFET 20 according to working statuses of the computer, so the light emitting diode 10 can correctly show the working statuses of the computer. When the computer is off, the controlling signal S2 is low, which enables the N-channel MOSFET 50 to be turned off, whether the controlling signal S1 is high or low, the light emitting diode 10 can not light to give a false indication. It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
|
G
|
G08
|
G08B
|
21
|
18
|
|||
11943416
|
US20090024281A1-20090122
|
STEER-BY-WIRE SYSTEM FOR AUTOMOBILES
|
ACCEPTED
|
20090107
|
20090122
|
[]
|
B62D600
|
["B62D600"]
|
7908056
|
20071120
|
20110315
|
701
|
042000
|
73692.0
|
NGUYEN
|
KIM
|
[{"inventor_name_last": "Hwang", "inventor_name_first": "Sung Wook", "inventor_city": "Anyang-si", "inventor_state": "", "inventor_country": "KR"}]
|
Disclosed herein is a steer-by-wire system for automobiles. The steer-by-wire system includes a steering control unit and a signal input unit. The central control unit includes a reaction force generation unit, a damping force generation unit. The reaction force generation unit generates steering reaction force or restoring force, acting in the reverse direction to that of a steering torque. The damping force generation unit generates damping force, acting in the reverse direction to the steering reaction force or the restoring force (in the same direction as the steering torque). Furthermore, the central control unit generates a current control signal, which is applied to a steering feel generation motor, by combining the resulting values determined by the reaction force generation unit and the damping force generation unit a vehicle velocity signal in response to a steering angle signal, a steering torque signal and a steering angular velocity signal.
|
1. A steer-by-wire system for automobiles, comprising: a steering control unit comprising a steering wheel; a steering feel generation motor mounted in the steering control unit; a central control unit for outputting a steering control signal, and a current control signal, which is applied to the steering feel generation motor, according to motion of the steering wheel; a steering mechanism unit comprising a rack motor for operating vehicle wheels in response to the steering control signal received from the central control unit; and a signal input unit comprising a vehicle velocity sensor, a steering angle sensor, a torque sensor, and a steering angular velocity sensor, and used to input a sensing signal, which is necessary for the central control unit to control the steering feel generation motor; wherein the central control unit receives a vehicle velocity signal, a steering angle signal, a steering torque signal and a steering angular velocity signal from the signal input unit, comprises a reaction force generation unit for generating steering reaction force or restoring force, acting in a reverse direction to that of a steering torque, and a damping force generation unit for generating damping force, acting in a reverse direction to the steering reaction force or the restoring force (in an identical direction to the steering torque), and generates the current control signal, which is applied to the steering feel generation motor, by combining resulting values determined by the reaction force generation unit and the damping force generation unit. 2. The steer-by-wire system as set forth in claim 1, wherein the central control unit further comprises a Proportional-Derivative (PD) control unit for receiving the steering angle signal, performing a proportional-derivative operation on the received steering angle signal, and outputting a resulting value to the reaction force generation unit, in order to more precisely control the steering reaction force or the restoring force. 3. The steer-by-wire system as set forth in claim 1 or 2, wherein: the central control unit further comprises a feedback signal unit for receiving feedback of a current value of the rack motor, performing operation on the current value along with the steering angular velocity signal, and outputting a resulting value, in order to control steering feel according to road conditions; and the central control unit outputs the current control signal, which is applied to the steering feel generation motor, through a combination of the resulting value, determined by the feedback signal unit, and the resulting values, determined by the reaction force generation unit and the damping force generation unit. 4. The steer-by-wire system as set forth in claim 1 or 2, wherein the reaction force generation unit further comprises a motor correction unit for determining a steering direction from the steering torque signal, determining a magnitude of the steering reaction force to correct a difference between frictional forces, attributable to left and right rotation of the rack motor, based on the steering direction, a vehicle velocity variable unit for determining a magnitude of the steering reaction force, which varies according to a vehicle velocity, from the vehicle velocity signal, and a torque variable unit for determining a magnitude of the steering reaction force, which varies according to steering, from the steering torque signal, in order to more precisely control the steering reaction force. 5. The steer-by-wire system as set forth in claim 4, wherein the central control unit outputs the current control signal, which is applied to the steering feel generation motor, through a combination of the resulting value, received from the PD control unit, and a resulting value, which is determined by the torque variable unit. 6. The steer-by-wire system as set forth in claim 1 or 2, wherein the reaction force generation unit further comprises a vehicle velocity restoration unit for determining a magnitude of the restoring force, which varies according to a vehicle velocity, from the vehicle velocity signal, and a steering angle restoration unit for determining a magnitude of the restoring force, which varies according to a steering angle, from the steering angle signal, in order to more precisely control the restoring force. 7. The steer-by-wire system as set forth in claim 1 or 2, wherein the reaction force generation unit further comprises a restoration determining function for determining whether the steering wheel is restored, from the steering angle signal. 8. The steer-by-wire system as set forth in claim 1 or 2, wherein the damping force generation unit further comprises a vehicle velocity damping unit for determining a magnitude of the damping force, which varies according to a vehicle velocity, from the vehicle velocity signal, a steering angular velocity damping unit for determining a magnitude of the damping force, which varies according to a steering angular velocity, from the steering angular velocity signal, and a steering angle damping unit for determining a magnitude of the damping force, which varies according to a steering angle, from the steering angle signal, in order to more precisely control the damping force. 9. The steer-by-wire system as set forth in claim 8, wherein the damping force generation unit further comprises a steering sign determination function for determining a steering sign from the steering torque signal. 10. The steer-by-wire system as set forth in claim 9, wherein the damping force generation unit combines resulting values, determined by the steering sign determination function, the steering angular velocity damping unit and the steering angle damping unit, and combines a resulting value, determined through a combination thereof, and a resulting value, determined by the vehicle velocity damping unit, thus outputting the current control signal which is applied to the steering feel generation motor.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to a steer-by-wire system for automobiles, in which control logic, which can generate damping force acting in the reverse direction to that of steering reaction force, correct a difference between the left and right frictional forces of a rack motor, and adjust a steering feel according to road conditions, is additionally provided, thus more precisely controlling steering reaction force (or restoring force), with the result that the steering feel can be improved. 2. Description of the Related Art Conventionally, a hydraulic system has been chiefly used as a power steering system. Such a hydraulic power steering system is configured such that a gear box, in which a pinion, connected on a steering column side, and a rack, connected on a vehicle wheel side via tie rods, are provided and are engaged with each other, is connected with an oil reservoir through a plurality of hoses so as to function as a power cylinder, and oil is supplied to both chambers of the gear box by an oil pump according to the direction in which a steering wheel is turned, and thus steering assistance force is generated. However, the above-described hydraulic system is complicated because it is constructed using complicated hydraulic lines, that is, because the oil reservoir, the oil pump, the gear box, and the plurality of hoses for connecting them must be provided. Furthermore, in the case of a hybrid vehicle using a small-displacement engine, operating an oil pump using an engine is not preferred in the point of view of the rate of fuel consumption. For this reason, a power steering system that is different from the hydraulic power steering system is required. A steer-by-wire system, which has been developed to solve the problems with the above-described hydraulic power steering system, is an electronic power steering system that transmits a signal, corresponding to the manipulation of a steering wheel, to vehicle wheels under the electronic control of a steering motor, without requiring any mechanical connection with a steering device. Although the steer-by-wire system is expected to be the next generation power steering system due to its advantages that the construction thereof is simple because a small number of mechanical devices is used and that the fuel consumption rate is decreased, the steer-by-wire system is problematic in that, unlike an automobile (hereinafter referred to as an “actually used vehicle”) that employs the hydraulic system, it does not provide a smooth steering feel,_because a digital control method using a steering motor, rather than an analog control method, such as that of the conventional hydraulic system, is used. In order to solve this problem, a design has been devised such that a reaction force motor is mounted in the column portion of a steering wheel, so that appropriate steering reaction and restoring forces are generated while a driver manipulates the steering wheel, therefore a steering feel similar to that of an actually used vehicle can be achieved. However, the existing steering-by-wire system is problematic in that the steering feel is still different from that of the actually used vehicle because the control logic of the existing steering-by-wire system is designed to focus only on the generation of steering reaction force and restoring force. The problem with the steering feel attributable to the conventional steer-by-wire system is described in detail. When the steering wheel is restored, overshoot occurs, and thus the on-center feel is decreased and a steering reaction force is excessively generated in proportion to the steering angle, with the result that excessive steering effort is necessary. Furthermore, since steering angular velocity is not considered, catch-up occurs when rapid steering is performed, and the steering feel is decreased due to the difference between left and right motor torques, attributable to the frictional force of a steering column and the inertia of the steering motor. The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and provides a steer-by-wire system, in which control logic, which can more precisely control the generation of steering reaction force and restoring force, generate an appropriate damping force acting in the reverse direction to that of the steering reaction force and the restoring force, depending on the steering torque of a steering wheel, correct a difference between left and right motor torques, and adjust the steering feel according to road conditions, is additionally provided, thus minimizing the difference in steering feel from the actually used vehicle. The present invention provides a steer-by-wire system for automobiles, including a steering control unit comprising a steering wheel; a steering feel generation motor mounted in the steering control unit; a central control unit for outputting a steering control signal, and a current control signal, which is applied to the steering feel generation motor, according to the motion of the steering wheel; a steering mechanism unit comprising a rack motor for operating vehicle wheels in response to the steering control signal received from the central control unit; and a signal input unit comprising a vehicle velocity sensor, a steering angle sensor, a torque sensor, and a steering angular velocity sensor, and used to input a sensing signal, which is necessary for the central control unit to control the steering feel generation motor; wherein the central control unit receives a vehicle velocity signal, a steering angle signal, a steering torque signal and a steering angular velocity signal from the signal input unit, comprises a reaction force generation unit for generating steering reaction force or restoring force, acting in the reverse direction to that of a steering torque, and a damping force generation unit for generating damping force, acting in the reverse direction to the steering reaction force or the restoring force (in the identical direction to the steering torque), and generates a current control signal, which is applied to the steering feel generation motor, by combining the resulting values determined by the reaction force generation unit and the damping force generation unit. The above features and advantages of the present invention will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description of the Invention, which together serve to explain by way of example the principles of the present invention.
|
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Korean Application No. 10-2007-0071758, filed on Jul. 18, 2007, the disclosure of which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a steer-by-wire system for automobiles, in which control logic, which can generate damping force acting in the reverse direction to that of steering reaction force, correct a difference between the left and right frictional forces of a rack motor, and adjust a steering feel according to road conditions, is additionally provided, thus more precisely controlling steering reaction force (or restoring force), with the result that the steering feel can be improved. 2. Description of the Related Art Conventionally, a hydraulic system has been chiefly used as a power steering system. Such a hydraulic power steering system is configured such that a gear box, in which a pinion, connected on a steering column side, and a rack, connected on a vehicle wheel side via tie rods, are provided and are engaged with each other, is connected with an oil reservoir through a plurality of hoses so as to function as a power cylinder, and oil is supplied to both chambers of the gear box by an oil pump according to the direction in which a steering wheel is turned, and thus steering assistance force is generated. However, the above-described hydraulic system is complicated because it is constructed using complicated hydraulic lines, that is, because the oil reservoir, the oil pump, the gear box, and the plurality of hoses for connecting them must be provided. Furthermore, in the case of a hybrid vehicle using a small-displacement engine, operating an oil pump using an engine is not preferred in the point of view of the rate of fuel consumption. For this reason, a power steering system that is different from the hydraulic power steering system is required. A steer-by-wire system, which has been developed to solve the problems with the above-described hydraulic power steering system, is an electronic power steering system that transmits a signal, corresponding to the manipulation of a steering wheel, to vehicle wheels under the electronic control of a steering motor, without requiring any mechanical connection with a steering device. Although the steer-by-wire system is expected to be the next generation power steering system due to its advantages that the construction thereof is simple because a small number of mechanical devices is used and that the fuel consumption rate is decreased, the steer-by-wire system is problematic in that, unlike an automobile (hereinafter referred to as an “actually used vehicle”) that employs the hydraulic system, it does not provide a smooth steering feel,_because a digital control method using a steering motor, rather than an analog control method, such as that of the conventional hydraulic system, is used. In order to solve this problem, a design has been devised such that a reaction force motor is mounted in the column portion of a steering wheel, so that appropriate steering reaction and restoring forces are generated while a driver manipulates the steering wheel, therefore a steering feel similar to that of an actually used vehicle can be achieved. However, the existing steering-by-wire system is problematic in that the steering feel is still different from that of the actually used vehicle because the control logic of the existing steering-by-wire system is designed to focus only on the generation of steering reaction force and restoring force. The problem with the steering feel attributable to the conventional steer-by-wire system is described in detail. When the steering wheel is restored, overshoot occurs, and thus the on-center feel is decreased and a steering reaction force is excessively generated in proportion to the steering angle, with the result that excessive steering effort is necessary. Furthermore, since steering angular velocity is not considered, catch-up occurs when rapid steering is performed, and the steering feel is decreased due to the difference between left and right motor torques, attributable to the frictional force of a steering column and the inertia of the steering motor. The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art. SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and provides a steer-by-wire system, in which control logic, which can more precisely control the generation of steering reaction force and restoring force, generate an appropriate damping force acting in the reverse direction to that of the steering reaction force and the restoring force, depending on the steering torque of a steering wheel, correct a difference between left and right motor torques, and adjust the steering feel according to road conditions, is additionally provided, thus minimizing the difference in steering feel from the actually used vehicle. The present invention provides a steer-by-wire system for automobiles, including a steering control unit comprising a steering wheel; a steering feel generation motor mounted in the steering control unit; a central control unit for outputting a steering control signal, and a current control signal, which is applied to the steering feel generation motor, according to the motion of the steering wheel; a steering mechanism unit comprising a rack motor for operating vehicle wheels in response to the steering control signal received from the central control unit; and a signal input unit comprising a vehicle velocity sensor, a steering angle sensor, a torque sensor, and a steering angular velocity sensor, and used to input a sensing signal, which is necessary for the central control unit to control the steering feel generation motor; wherein the central control unit receives a vehicle velocity signal, a steering angle signal, a steering torque signal and a steering angular velocity signal from the signal input unit, comprises a reaction force generation unit for generating steering reaction force or restoring force, acting in the reverse direction to that of a steering torque, and a damping force generation unit for generating damping force, acting in the reverse direction to the steering reaction force or the restoring force (in the identical direction to the steering torque), and generates a current control signal, which is applied to the steering feel generation motor, by combining the resulting values determined by the reaction force generation unit and the damping force generation unit. The above features and advantages of the present invention will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description of the Invention, which together serve to explain by way of example the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: FIG. 1 is a diagram showing the overall construction of a steer-by-wire system according to the present invention; FIG. 2 is a block diagram showing principal parts of the steer-by-wire system according to the present invention; FIG. 3 is a block diagram showing the control logic of a PD controller according to the present invention; FIG. 4 is a block diagram showing the control logic of a reaction force generation unit according to the present invention; FIG. 5 is a block diagram showing the control logic of a damping force generation unit according to the present invention; FIG. 6 is a diagram illustrating a method of controlling steering feel according to an embodiment of the present invention; FIG. 7 is a graph showing the degree of improvement of steering feel according to the present invention; and FIG. 8 is another graph showing the degree of improvement of steering feel according to the present invention. However, it should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. The basic construction of a steer-by-wire system for automobiles according to the present invention is described with reference to FIG. 1 below. The steer-by-wire system is a next generation steering device, and is configured such that a steering control unit 100, which is coupled with a steering wheel, and a steering mechanism unit 400, which is provided with a rack motor and a gear box, are independently separated from each other without directly connecting them using mechanical coupling elements, such as universal joints, and a central control unit 300 operates the rack motor of the steering mechanism unit 400 by outputting a necessary steering control signal according to the motion of the steering wheel, and thus vehicle wheels are controlled. According to the steer-by wire system of the present invention, the central control unit 300 receives a current vehicle velocity signal, a steering angle signal, a steering torque signal, a steering angular velocity signal from a signal input unit 500, including a vehicle velocity sensor 510, which is mounted on a vehicle, a steering angle sensor 520, a torque sensor 530 and a steering angular velocity sensor 540, which are mounted on the steering control unit 100, generates steering reaction force and restoring force, which act in the reverse direction to that of a driver's steering torque, and damping force, which acts in the reverse direction to that of the steering reaction and restoring forces (in the same direction as the steering torque), and applies a final current value control signal, which is generated by combining the generated forces, to a steering feel generation motor 200 mounted in the steering control unit 100, thus enabling the driver to experience a steering feel similar to that of an actually used vehicle. In order to create a steering feel, the conventional steer-by-wire system uses only control logic that is designed such that the central control unit 300 merely receives the vehicle velocity signal, the steering torque signal and the steering angle signal and generates only the steering reaction and restoring forces. In contrast, the steer-by-wire system of the present invention includes control logic that is configured such that the central control unit 300 additionally receives the steering angular velocity signal and more precisely controls the steering reaction force and the restoring force, and additionally generates a damping force that acts in the reverse direction to that of the steering reaction force and the restoring force. Furthermore, a final current value control signal, which is applied to the steering feel generation motor 200, is output through the combination of the steering reaction force, the restoring force and the damping force, so that the difference in steering feel from the actually used vehicle can be minimized. Furthermore, the steer-by-wire system of the present invention corrects a difference between frictional forces in the left and right directions of the rack motor, and includes control logic that can adjust the steering feel according to road conditions, thus improving the steering feel. An embodiment of a steer-by-wire system for automobiles according to the present invention is described in detail with reference to the accompanying drawings, that is, FIGS. 2 to 8. FIG. 2 shows a central control unit 300 and a signal input unit 500, which are principal parts of the steer-by-wire system according to the present invention. Referring to FIG. 2, the signal input unit 500 includes a vehicle velocity sensor 510, a steering angle sensor 520, a torque sensor 530 and a steering angular velocity sensor 540. The vehicle velocity sensor 510 is mounted in a predetermined location in a vehicle and senses the driving velocity of the vehicle. The other sensors, that is, the steering angle sensor 520, the torque sensor 530 and the steering angular velocity sensor 540, are connected and mounted to the steering wheel, and respectively sense a steering angle, the driver's steering torque and a steering angular velocity, which are generated according to the motion of the steering wheel, and then input them to the central control unit 300. The central control unit 300 includes a reaction force generation unit 310 for receiving a vehicle velocity signal, a steering angle signal, a steering torque signal from the signal input unit 500, and generating steering reaction force and restoring force [for convenience, indicated as (+)], acting in the reverse direction to that of the steering torque, and a damping force generation unit 340 for generating damping force [for convenience, indicated as (−)], acting in the reverse direction to that of the steering reaction force and the restoring force (in the same direction as the steering torque). Furthermore, the central control unit 300 combines the resulting values, which are determined by the reaction force generation unit 310 and the damping force generation unit 340, and outputs a current control signal which is applied to the steering feel generation motor 200. As described above, in the present invention, the damping force, acting in the same direction as the driver's steering torque, is additionally provided, and the damping force and the steering reaction and restoring forces are appropriately combined, unlike the conventional technology, which uses only the steering reaction and restoring forces, acting in the reverse direction to that of the driver's steering torque, so that steering feel can be further improved. The detailed construction of the reaction force generation unit 310 and the damping force generation unit 340 will be described later with reference to FIGS. 4 and 5. In order to more precisely control the steering reaction force or the restoring force, the central control unit 300 further includes a Proportional-Derivative (PD) control unit 320 for receiving the steering angle signal, performing a proportional-derivative operation on the received steering angle signal, and then outputting the resulting value to the reaction force generation unit 310. That is, in the present invention, a PD control method is used to adjust the steering feel depending on the steering angle, as shown in FIG. 3. In greater detail, the PD control unit 320 sets a steering angle signal, which is generated when the steering angle is 0 degrees, as a reference value, and handles the other steering angle signals as error values, and generates steering reaction force (or restoring force) using both an operational logic 322 for adding a P gain (Kp) 321 in proportion to the magnitude of each error value and an operational logic 324 for adding a D gain (Kd) 323 according to variation in the magnitude of each error value, while reducing the fluctuation of the steering reaction force (or restoring force). Accordingly, when the steering wheel is restored, overshoot attributable to excessive restoring force decreases, and thus the on-center feel at a neutral angle is improved. Meanwhile, in order to adjust the steering feel according to the road conditions, the central control unit 300 may further include a feedback signal unit 350 for receiving the feedback of the current value of the rack motor, performing operation on the received current value of the rack motor and the steering angular velocity signal input from the steering angular velocity sensor 540, and outputting the resulting value. Furthermore, the central control unit 300 combines the value determined by the feedback signal unit 350 with the values determined by the reaction force generation unit 310 and the damping force generation unit 340, and thus outputs the current control signal which is applied to the steering feel generation motor 200. The current value of the rack motor varies according to road conditions. When the surface of the road is rough, the current value of the rack motor increases because the resistance value of the road increases. In contrast, when the surface of the road is smooth, the current value of the rack motor decreases because the resistance value of the road decreases. Furthermore, the steering angular velocity varies according to the road conditions even when the driver applies the same force. In consideration of these points, the present invention feeds back the current value of the rack motor, and divides the current value into current values for respective sections (preferably first section: more than 15 amperes, second section: 10˜14 amperes, third section: less than 10 amperes), performs operation on the current values with respect to the respective sections along with the steering angular velocity signal, and applies the resulting values for the respective sections to the increase and decrease of the steering reaction force, thus providing an optimal steering feel. Meanwhile, a motor torque correction unit 330 for correcting the difference between frictional forces in the left and right directions of the rack motor using the steering angle signal received from the steering angle sensor 520 may be additionally provided. The details of the motor torque correction are described in conjunction with the technical construction of the reaction force generation unit 310 below. FIG. 4 shows the detailed technical construction of the reaction force generation unit 310 according to the present invention. The reaction force generation unit 310 is a control logic that performs operations necessary to generate the steering reaction force or the restoring force, which acts in the reverse direction to the driver's steering torque, and includes a steering reaction force generation block 350 and a restoring force generation block 360. For reference, in the present invention, the control logic refers to a software program, rather than a hardware construction. In order to more precisely control the steering reaction force, the steering reaction force generation block 350 includes a motor correction unit 311 for determining the steering direction from the steering torque signal, determining the magnitude of the steering reaction force to correct the difference between frictional forces, attributable to the left and right rotation of the rack motor, based on the steering direction, a vehicle velocity variable unit 312 for determining the magnitude of the steering reaction force, which varies according to the vehicle velocity, from the vehicle velocity signal, and a torque variable unit 313 for determining the magnitude of the steering reaction force, which varies according to steering, from the steering torque signal. The motor correction unit 311 performs the same function as the motor torque correction unit 330. Generally, a rack motor causes the difference between frictional forces in the left and right directions. Conventionally, when the driver rotates the steering wheel in the left and right directions, he or she can feel a slight difference because no correction for the difference is performed. However, the present invention generates the steering reaction force so as to prevent any difference between the left and right frictional forces from occurring using the motor correction unit 311 and the motor torque correction unit 330, thus minimizing the difference in steering feel from the actually used vehicle. The vehicle velocity variable unit 312 determines the magnitude of the steering reaction force from the vehicle velocity signal received from the vehicle velocity sensor 510. For example, the steering wheel is made heavy by increasing the steering reaction force at the time of stoppage, reducing the steering reaction force as the vehicle velocity gradually increases, and increasing the steering reaction force again when the vehicle velocity is equal to or greater than a predetermined vehicle velocity. When the steering wheel rotates by an amount equal to or greater than a predetermined angle (at the time of steering), the torque variable unit 313 makes the steering wheel difficult to turn by increasing the steering reaction force. In contrast, when the steering wheel rotates by an amount smaller than a predetermined angle (at the time of non-steering), the torque variable unit 313 adjusts the steering feel by decreasing the steering reaction force. Furthermore, the central control unit 300 may be configured to output the current control signal, which is applied to the steering feel generation motor 200, through the operational logic 317 combining the resulting value received from the PD control unit 320 and the resulting value determined by the torque variable unit 313. For example, the influence caused by the damping force is increased by increasing the steering reaction force using the output value of the PD control unit 320 unchanged at the time of steering and decreasing the output value of the PD control unit 320 at the time of non-steering. Meanwhile, in order to more precisely control the restoring force generated when the steering wheel is restored, the restoring force generation block 360 includes a vehicle velocity restoration unit 314 for determining the magnitude of the restoring force, which varies according to the vehicle velocity, from the vehicle velocity signal of the vehicle velocity sensor 510, and a steering angle restoration unit 315 for determining the magnitude of the restoring force, which varies according to the steering angle, from the steering angle signal of the steering angle sensor 520. The steering feel is adjusted in such a way that the vehicle velocity restoration unit 314 increases the restoring force as the vehicle velocity increases, and the steering angle restoration unit 315 increases or decreases the left and right directions and the magnitude of the steering angle. Meanwhile, the reaction force generation unit 310 may further include a restoration determining function 316 for determining whether the steering wheel is restored. The restoration determining function 316 determines whether the steering wheel is restored based on the direction and magnitude of the steering angle signal received from the steering angle sensor 520. The resulting values of the vehicle velocity restoration unit 314 and the steering angle restoration unit 315 are combined by an operational logic 318, and the resulting value is selectively output via a switch 319 in response to a signal from the restoration determining function 316. FIG. 5 shows the damping force generation unit 340 according to the present invention, which is the most characteristic technical element. In order to more precisely control the damping force, the damping force generation unit 340 includes a vehicle velocity damping unit 341 for determining the magnitude of the damping force, which varies according to the vehicle velocity, from the vehicle velocity signal of the vehicle velocity sensor 510, a steering angular velocity damping unit 343 for determining the magnitude of the damping force, which varies according to the steering angular velocity, from the steering angular velocity signal of the steering angle velocity sensor 540, and a steering angle damping unit 344 for determining the magnitude of the damping force, which varies according to the steering angle, from the steering angle signal of the steering angle sensor 520. In order to generate a steering feel similar to that of an actually used vehicle, the vehicle velocity damping unit 341 decreases the influence on damping by decreasing the damping force when the vehicle velocity is high (the steering reaction force may be increased through the generation of a negative damping force at a velocity equal to or greater than a predetermined velocity), but increases the influence on damping by increasing the damping force when the vehicle velocity is low. However, if the vehicle velocity is high but the damping force is too small, the driving stability of the vehicle is lowered. Accordingly, when the vehicle velocity is high, the yaw stability of the vehicle can be assured by increasing the damping force so that it is greater than that of an actually used vehicle. The steering angular velocity damping unit 343 decreases the steering reaction force by increasing the damping force as the steering angular velocity increases, and thus prevents catch-up from occurring. However, in the case where a large damping force occurs at a very rapid steering angular velocity, the steering reaction force becomes weak, and thus the driving stability can be lowered. For this reason, damping and steering reaction force, which are similar to those of an actually used vehicle, are realized using Hardware-In-the-Loop Simulation (HILS). The steering angle damping unit 344 increases the damping force in an on-center interval, so that motor drive torque decreases overall, therefore restraining overshoot. Furthermore, the steering angle damping unit 344 adjusts the restoration velocity for each steering angle when the steering angle is restored. When the steering angle increases, the steering angle damping unit 344 decreases the influence on damping so that a more rapid response can be acquired through the decrease of the damping force. Meanwhile, the damping force generation unit 340 may further include a steering sign determination function 342 for determining a steering sign from the steering torque signal. The steering sign determination function 342 is used to distinguish handle steering and non-steering from each other using the torque sensor 530. If a damping force exists when the driver conducts steering, the motor drive torque value decreases, so that the steering reaction force decreases, therefore catch-up can be prevented. In contrast, when the driver does not conduct steering, the damping force decreases, and thus natural restoration performance can be assured. For this reason, the steering sign determination function 342 may be used to control the damping force. The damping force generation unit 340 includes an operational logic 345 for combining the resulting values, determined by the steering sign determination function 342, the steering angular velocity damping unit 343 and the steering angle damping unit 344, and an operational logic 346 for combining the resulting value, determined by the operational logic 345, and the resulting value, determined by the vehicle velocity damping unit 341, and outputs the current control signal, which is applied to the steering feel generation motor 200, depending on the resulting value determined by the operational logic 346. Accordingly, the damping force generation unit 340 of the present invention can output a damping force, which enables the generation of an optical steering feel, by combining values, determined by the steering sign determination function 342, the steering angular velocity damping unit 343 and the steering angle damping unit 344, using a value determined by the vehicle velocity damping unit 341. FIG. 6 is a schematic diagram illustrating an example of a control method using the steer-by-wire system of the present invention, which is constructed as described above. First, the central control unit 300 determines whether the steering wheel is restored, from signals received from the steering angle sensor 520 at step S10. This determination may be made by the restoration determining function 316 of the reaction force generation unit 310. If, as a result of the determination of restoration, it is determined that the steering wheel has not been restored, the steering angle signal received from the steering angle sensor 520 is input to the PD control unit 320, and torque signal received from torque sensor 530 is input to the torque variable unit 313. The resulting value is determined by combination of the values of the torque variable unit 313 and the PD control unit 320, and therefore a (+) directional resulting value for the steering reaction force is determined. Meanwhile, the vehicle velocity damping unit 341 determines the magnitude of the damping force, depending on variation in vehicle velocity, from the vehicle velocity signal received from the vehicle velocity sensor 510. The steering angular velocity damping unit 343 determines the magnitude of the damping force, depending on variation in steering angular velocity, from the steering angular velocity signal received from steering angular velocity sensor 540. Furthermore, the steering angle damping unit 344 determines the magnitude of the damping force, depending on variation in steering angle, from the steering angle signal received from steering angle sensor 520. Subsequently, the (−) directional resulting values, i.e. the combination of damping forces which are determined by the vehicle velocity damping unit 341, the steering angular velocity damping unit 343 and the steering angle damping unit 344, and the (+) directional resulting value, i.e, steering reaction force, which is determined by the torque variable unit 313 and PD control unit 320, are combined, and thus a final current control signal, which is applied to the rack motor, is output at step S20. In contrast, if, as a result of the determination of restoration determination at step S10, it is determined that the steering wheel has been restored, the steering reaction force is determined by the torque variable unit 313 which determines the magnitude of the steering reaction force from the driver's steering torque signal received from the torque sensor 530 and the PD control unit 320 which determine the magnitude of the steering reaction force from the driver's steering angle signal received from the steering angle sensor 520. Further, the restoring force is determined by the vehicle velocity restoration unit 314 which determines the magnitude of the restoring force from the vehicle velocity signal received from the vehicle velocity sensor 510, and the steering angle restoration unit 315 which determines the magnitude of the restoring force from the steering angle signal received from the steering angle sensor 520. Subsequently, a (+) directional resulting value is determined through the combination of these steering reaction forces and the restoring force, at step S30. Meanwhile, in the same manner as in the case of the non-restoration, the vehicle velocity damping unit 341, the steering angular velocity damping unit 343, the steering angle damping unit 344 respectively determine the magnitude of the damping force. Subsequently, the (−) directional resulting values of the damping forces determined by the vehicle velocity damping unit 341, the steering angular velocity damping unit 343 and the steering angle damping unit 344, and the (+) directional resulting value of steering reaction force and restoring, which is determined at step 30, are combined, and thus the final current control signal, which is applied to the rack motor, is output at step 40. FIGS. 7 and 8 are graphs showing experimental results determined using the control system of the present invention. As can be seen from FIG. 7, the conventional control system exhibits non-uniform steering torque as the steering angle of a steering wheel increases, whereas the control system of the present invention exhibits uniform steering torque even when the steering angle increases steering torque, thus providing a steering feel similar that of the actually used vehicle. FIG. 8 shows experimental results determined when the degree of restoration is measured in the case where the steering wheel of a vehicle, moving at a constant velocity and a constant steering angle, is released. In the conventional control system, excessive restoring force occurs, and thus the steering angle is changed to a (−) directional steering angle (which means that overshoot has occurred). However, in the control system of the present invention, the steering angle is converted to be within the range of 20˜30° in the (+) direction, and thus a steering feel similar to an actually used vehicle can be achieved. Due to the above-described characteristic technical construction, the present invention not only allows a driver to experience the same steering feel as that of a vehicle in which a hydraulic power steering device is mounted, but also generates an optimal steering feel according to the driving velocity of a vehicle and the manipulation of the steering wheel, conducted by the driver, so that it can improve the driving stability of the vehicle. The forgoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiment were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that technical spirit and scope of the present invention be defined by the claims appended hereto and their equivalents.
|
B
|
B62
|
B62D
|
6
|
00
|
|||
11863600
|
US20090087324A1-20090402
|
FUEL PUMP END CAP WITH ISOLATED SHUNT WIRES
|
ACCEPTED
|
20090318
|
20090402
|
[]
|
H02K500
|
["H02K500", "H02K1102", "H02K714"]
|
7874816
|
20070928
|
20110125
|
417
|
423140
|
66484.0
|
BERTHEAUD
|
PETER
|
[{"inventor_name_last": "Fischer", "inventor_name_first": "John G.", "inventor_city": "Goodrich", "inventor_state": "MI", "inventor_country": "US"}, {"inventor_name_last": "Ball", "inventor_name_first": "Robert J.W.", "inventor_city": "Flint", "inventor_state": "MI", "inventor_country": "US"}]
|
An end cap assembly for an in-tank fuel pump is configured to close an open end of a pump housing and includes an end cap body and a companion clip. On the bottom side of the end cap body facing the pump housing is a pair of motor brush wells for holding a pair of DC motor brushes. A pair of blind bores are provided to receive corresponding RFI suppression circuits. A pair of pockets are located in between the wells and the bores to allow flexible shunt wires to connect the RFI suppression circuits with the brushes. The clip is adapted for insertion into the bottom of the end cap body wherein a pair of axially-extending legs are guided into and seal the pockets. The captured shunt wires are electrically isolated in the closed pockets and contact with fuel is minimized.
|
1. An end cap assembly for an in-tank fuel pump, comprising: an end cap body having an axis configured to close an opening of a pump housing, said body including a fuel outlet and a connector having positive and negative polarity electrical terminals, said body further including a pair of brush wells configured for receiving a corresponding pair of motor brushes and opening towards a side of said body opposite said outlet, said body further includes a pair of blind bores each configured to receive a respective radio frequency interference (RFI) suppression circuit, said body further including a pair of pockets adjacent to said wells configured to allow a pair of flexible shunt wires to connect said brushes to said RFI suppression circuits; and a clip configured for insertion into said end cap body to close said pockets. 2. The assembly of claim 1 wherein each of said wells have a respective, axially-extending slot to allow for travel of the flexible shunt wire, said clip having a main base with a pair of axially-extending legs, said legs being configured to capture said flexible shunt wires, said legs being further configured, upon insertion into said end cap body, to form a closure wall closing said pockets. 3. The assembly of claim 2 wherein said legs each include a notch on a distal end thereof configured to capture a respective one of said flexible shunt wires. 4. The assembly of claim 3 wherein said notch is concave and is sized to capture said flexible shunt wire while creating a seal against a floor of said pocket. 5. The assembly of claim 2 wherein said end cap body includes a set of axially-extending lands configured to guide insertion of one of said legs. 6. The assembly of claim 5 wherein said set is a first set, said end cap body further includes a second set of axially-extending lands configured to guide insertion of the other one of said legs. 7. The assembly of claim 2 wherein each pocket includes a respective fixed wall, said clip including a pair of an axially-extending end walls configured to abut said fixed walls. 8. The assembly of claim 2 wherein said clip includes a pair of slot closure members, each slot closure member being configured to cover said slots. 9. The assembly of claim 1 wherein said housing is configured to be disposed in a fuel reservoir. 10. The assembly of claim 1 wherein said RFI suppression circuits each comprise a respective coil and ferromagnetic core. 11. The assembly of claim 1 wherein said flexible shut wires are side-mounted to said brushes. 12. The assembly of claim 1 wherein said flexible shunt wires comprise braided wire.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Referring to FIG. 10 , it is known to provide an electrically-operated, in-tank fuel pump 100 . Pump 100 includes a main pump housing 102 and an end cap 104 . It is common to equip electrical pumps of this type with a brush type (e.g., DC) electric motor. End cap 104 includes a fluid outlet 106 for outputting the flow of pumped fuel, and an electrical connector 108 that includes a pair of electrical terminals configured for connection to an external wiring harness, for example. The electrical terminals of the connector 108 are typically used for providing positive and negative polarity DC voltage to the pump to energize the electric motor. The DC voltage across the positive and negative terminals is subsequently applied via a pair of DC motor brushes to a motor armature or the like. The DC motor brushes (not shown in FIG. 10 ) are typically spring-biased to allow for movement during the operating life of the pump 100 (i.e., to maintain a positive contact as the brushes themselves wear out). In view of this, it also known to provide a pair of so-called flexible shunt wires, which may be braided wires, to connect each of the electrical terminals to its respective brush. However, when the pump 100 is used in high alcohol content based fuels or other fuels with increased electrical conductivity, the flexible shunt wires are subject to, and in-fact experience, degradation. In particular, electrolysis of the positive shunt wire causes metal loss, which may ultimately result in an open circuit condition, causing a failed fuel pump. FIGS. 11-13 show one approach taken in the art to address this problem, with FIG. 11 being a top view and FIGS. 12 and 13 being cross-sectional views taken substantially along lines 12 - 12 and 13 - 13 in FIG. 11 , respectively. This approach calls for protecting the shunt wires from electrolysis by arranging the brushes with axial shunt wires that are contained in the same bore that houses the motor brush (i.e., are isolated within the brush bore and thus electrically isolated from the other, opposite polarity shunt wire/terminal). FIG. 13 shows a pair of bores 110 with respective brushes 112 and shunt wires 114 . By creating a high resistance electrical path between the anode and cathode, any adverse effect of electrolysis is minimized. However, the axial shunt design is undesirable due to the difficulty in integrating the shunt wire into a radio frequency suppression circuit. For example, a common RFI circuit includes a coil and ferromagnetic core assembly, which in this conventional approach would have to occupy the same axial space as the springs that bias the brushes. Accordingly, for axial shunt wire designs, it is common to include a secondary RFI module 116 and electrical connector, offset from axial alignment, as required to accomplish this function, as seen in FIG. 12 . FIGS. 14-15 show another approach taken in the art, namely, a side-connected shunt wire design. FIG. 14 is a partially broken away side view of an end cap showing an electrical terminal 118 , a first end 120 of a coil 122 , a second end 124 of the coil 122 , a core 126 , a flexible shunt wire 128 and a side-mounted connection 130 to brush 132 . A desirable method to integrate the brush 132 and shunt wire 128 into an radio frequency interference (RFI) suppression circuit is to use a side shunt design that provides for the shunt wire attachment directly to the RFI circuit (i.e., coil and core) in a design that integrates the brushes, RFI circuit and electrical terminals all in one brush carrier or end cap assembly. However, this known method provides no electrical isolation between the opposite polarity shunt wires, as would be needed to minimize or prevent electrolysis. FIG. 15 shows a positive polarity shunt wire 134 , a negative polarity shunt wire 136 and a path 138 through which electrolysis proceeds in the presence of an electrically conductive fuel. There is therefore a need for a fuel pump end cap assembly that minimizes or eliminates one or more of the problems set forth above.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides the means for electrically isolating the flexible shunt wires of an in-tank fuel pump end cap, while maintaining the use of the more desirable, lower cost side-orientation shunt wire-to-brush connection and integrated RFI design. An end cap assembly for an in-tank fuel pump includes an end cap body and a clip. The end cap body (or carrier) extends generally along an axis and is configured to close an opening of a pump housing. The end cap body includes a fuel outlet and a connector having positive and negative polarity electrical terminals. On the bottom side of the body (i.e., the side opposite the fuel outlet and connector), a pair of brush wells are formed and are configured to receive a corresponding pair of motor brushes. Also on the bottom side are a pair of blind bores each of which is configured to receive a respective radio frequency interference (RFI) suppression circuit. The end cap body further includes a pair of pockets each of which are located adjacent to the brush well and corresponding RFI bore, and are each configured (e.g., with an opening) to allow a flexible shunt wire to pass through for connecting the brush to the RFI suppression circuit. The clip includes a pair of axially-extending legs. The clip is configured to be inserted into the bottom of the end cap body, where each leg slides into one of the pockets, closing the pocket and capturing and isolating the shunt wire. The isolated shunt wires are thus substantially, electrically isolated from surfaces of opposite electrical polarity, minimizing or eliminating the occurrence of electrolysis. The isolated pockets also protect the shunt wires from chemical corrosion by limiting exposure to chemical agents (e.g., sulfur) in the fuel. The closed, sealed pockets prevent replenishment of such chemical agents from surrounding fuel, thereby reducing the concentration thereof (which reduces corrosion). Other objects, features and advantages are also presented.
|
TECHNICAL FIELD The present invention relates generally to fuel system components and more particularly to a fuel pump end cap assembly with isolated shunt wires. BACKGROUND OF THE INVENTION Referring to FIG. 10, it is known to provide an electrically-operated, in-tank fuel pump 100. Pump 100 includes a main pump housing 102 and an end cap 104. It is common to equip electrical pumps of this type with a brush type (e.g., DC) electric motor. End cap 104 includes a fluid outlet 106 for outputting the flow of pumped fuel, and an electrical connector 108 that includes a pair of electrical terminals configured for connection to an external wiring harness, for example. The electrical terminals of the connector 108 are typically used for providing positive and negative polarity DC voltage to the pump to energize the electric motor. The DC voltage across the positive and negative terminals is subsequently applied via a pair of DC motor brushes to a motor armature or the like. The DC motor brushes (not shown in FIG. 10) are typically spring-biased to allow for movement during the operating life of the pump 100 (i.e., to maintain a positive contact as the brushes themselves wear out). In view of this, it also known to provide a pair of so-called flexible shunt wires, which may be braided wires, to connect each of the electrical terminals to its respective brush. However, when the pump 100 is used in high alcohol content based fuels or other fuels with increased electrical conductivity, the flexible shunt wires are subject to, and in-fact experience, degradation. In particular, electrolysis of the positive shunt wire causes metal loss, which may ultimately result in an open circuit condition, causing a failed fuel pump. FIGS. 11-13 show one approach taken in the art to address this problem, with FIG. 11 being a top view and FIGS. 12 and 13 being cross-sectional views taken substantially along lines 12-12 and 13-13 in FIG. 11, respectively. This approach calls for protecting the shunt wires from electrolysis by arranging the brushes with axial shunt wires that are contained in the same bore that houses the motor brush (i.e., are isolated within the brush bore and thus electrically isolated from the other, opposite polarity shunt wire/terminal). FIG. 13 shows a pair of bores 110 with respective brushes 112 and shunt wires 114. By creating a high resistance electrical path between the anode and cathode, any adverse effect of electrolysis is minimized. However, the axial shunt design is undesirable due to the difficulty in integrating the shunt wire into a radio frequency suppression circuit. For example, a common RFI circuit includes a coil and ferromagnetic core assembly, which in this conventional approach would have to occupy the same axial space as the springs that bias the brushes. Accordingly, for axial shunt wire designs, it is common to include a secondary RFI module 116 and electrical connector, offset from axial alignment, as required to accomplish this function, as seen in FIG. 12. FIGS. 14-15 show another approach taken in the art, namely, a side-connected shunt wire design. FIG. 14 is a partially broken away side view of an end cap showing an electrical terminal 118, a first end 120 of a coil 122, a second end 124 of the coil 122, a core 126, a flexible shunt wire 128 and a side-mounted connection 130 to brush 132. A desirable method to integrate the brush 132 and shunt wire 128 into an radio frequency interference (RFI) suppression circuit is to use a side shunt design that provides for the shunt wire attachment directly to the RFI circuit (i.e., coil and core) in a design that integrates the brushes, RFI circuit and electrical terminals all in one brush carrier or end cap assembly. However, this known method provides no electrical isolation between the opposite polarity shunt wires, as would be needed to minimize or prevent electrolysis. FIG. 15 shows a positive polarity shunt wire 134, a negative polarity shunt wire 136 and a path 138 through which electrolysis proceeds in the presence of an electrically conductive fuel. There is therefore a need for a fuel pump end cap assembly that minimizes or eliminates one or more of the problems set forth above. SUMMARY OF THE INVENTION The present invention provides the means for electrically isolating the flexible shunt wires of an in-tank fuel pump end cap, while maintaining the use of the more desirable, lower cost side-orientation shunt wire-to-brush connection and integrated RFI design. An end cap assembly for an in-tank fuel pump includes an end cap body and a clip. The end cap body (or carrier) extends generally along an axis and is configured to close an opening of a pump housing. The end cap body includes a fuel outlet and a connector having positive and negative polarity electrical terminals. On the bottom side of the body (i.e., the side opposite the fuel outlet and connector), a pair of brush wells are formed and are configured to receive a corresponding pair of motor brushes. Also on the bottom side are a pair of blind bores each of which is configured to receive a respective radio frequency interference (RFI) suppression circuit. The end cap body further includes a pair of pockets each of which are located adjacent to the brush well and corresponding RFI bore, and are each configured (e.g., with an opening) to allow a flexible shunt wire to pass through for connecting the brush to the RFI suppression circuit. The clip includes a pair of axially-extending legs. The clip is configured to be inserted into the bottom of the end cap body, where each leg slides into one of the pockets, closing the pocket and capturing and isolating the shunt wire. The isolated shunt wires are thus substantially, electrically isolated from surfaces of opposite electrical polarity, minimizing or eliminating the occurrence of electrolysis. The isolated pockets also protect the shunt wires from chemical corrosion by limiting exposure to chemical agents (e.g., sulfur) in the fuel. The closed, sealed pockets prevent replenishment of such chemical agents from surrounding fuel, thereby reducing the concentration thereof (which reduces corrosion). Other objects, features and advantages are also presented. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described by way of example, with reference to the accompanying drawings: FIG. 1 is a top, perspective view of an embodiment of an end cap assembly according to the invention. FIG. 2 is a bottom, perspective view of an end cap body of FIG. 1, without a cooperating clip installed. FIG. 3 is a perspective view of clip for use with the end cap body. FIG. 4 is a bottom, perspective view showing the clip of FIG. 3 partially installed in the end cap body. FIG. 5 is a bottom, perspective view of the end cap assembly with the clip of FIG. 3 fully installed. FIG. 6 is a partial, cross-sectional view taken substantially along lines 6-6 of FIG. 5 showing a leg of the clip capturing the flexible wire shunt. FIG. 7 is an enlarged, cross-sectional view taken substantially along lines 7-7 of FIG. 5 showing the formed isolation pockets. FIG. 8 is an enlarged, perspective view of FIG. 2. FIG. 9 is a diagrammatic representation of an assembly process of the end cap assembly of the present invention. FIG. 10 is a perspective view of a prior art in-tank electrical fuel pump with end cap. FIGS. 11-13 show one prior art end cap incorporating an axially-disposed shunt wire design. FIGS. 14-15 show another prior art end cap incorporating a side shunt wire design. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings wherein like reference numerals are used to identify identical components in the various views, FIG. 1 is a top perspective view of an end cap assembly 10 for use in an in-tank fuel pump, such as like the fuel pump 100 with fuel pump housing 102 shown in FIG. 10. Being an in-tank variety of fuel pump, the end cap assembly and the pump housing are configured to be disposed in a reservoir of fuel (e.g., fuel tank) where contact with fuel is expected. The end cap assembly 10 includes an end cap body (or carrier) 12 and a clip 14 (best shown in FIG. 3). Body 12 may be fabricated using conventional materials suitable for use in an environment where exposure to various fuels, including gasoline and gasoline/alcohol blends, are expected. For example, polyphenolsulfide (PPS) may be used for the end cap body 12. In the illustrated embodiment, end cap body 12 is generally cylindrical, extending along a main axis “A”. However, it should be understood that the body 12 need not be cylindrical, only that it be configured to close an opening in pump housing, such as pump housing 102 (FIG. 10). Body 12 includes a fuel outlet 16 configured to provide a pumped flow of fuel to an external tube or the like. In the illustrated embodiment, outlet 16 is barbed; however, this is a matter of design choice, and in any embodiment, outlet 16 would be adapted to meet the particular interface requirements of that application. Body 12 further includes a connector 18, which in the illustrated embodiment has electrical terminals 20 disposed therein. In an embodiment where the in-tank fuel pump is DC motor-based, the electrical terminals 20 would include at least a positive polarity and a negative polarity electrical terminal for providing a DC voltage for energizing the DC motor. It should be appreciated that other variations are possible, and the particular type of motor selected would determine the configuration of the needed electrical terminals. Body 12, as shown, also includes a pair of axially-extending, hollow towers 22, which define a corresponding pair of motor brush wells 24, which having openings that may be accessed from the bottom side of the body 12 (i.e., the side that would face towards the pump housing). Finally, the body 12 includes suitable structural and functional attachment and sealing features 26 that allow it to close an opening of the pump housing. The attachment and sealing features 26 may reflect conventional approaches taken in the art for these purposes. FIG. 2 is a perspective view of the end cap body 12 as viewed toward the bottom side, but without the clip 14 installed. FIG. 2 shows the brush wells 24 each containing one of a corresponding pair of motor brushes 26. As known, the brushes 26 comprise electrically conductive material and function to apply the voltages to a motor armature or the like, for example a DC voltage where a DC motor is being energized. Body 12 also includes a pair of blind bores 28 that are configured to receive a corresponding radio frequency interference (RFI) suppression circuit 30. In the illustrated embodiment, the blind bores 28 are circular in shape due to the fact that a common RFI suppression circuit is cylindrical in shape (i.e., includes a coil formed around a ferromagnetic cylindrical-shaped core). However, it should be understood that this is exemplary only and not limiting in nature. The blind bores 28 may be configured to correspond to the particular packaging in which the desired RFI suppression circuit in provided. FIG. 2 shows that the end cap body 12 further includes a pair of axially-extending pockets 32 formed by various walls internal to the body 12. Each pocket 32 has access to an adjacent brush well 24 by virtue of a respective axially-extending slot 34. This arrangement allows a flexible shunt wire 36 that is disposed in pocket 32 to pass through the slot 34 into the brush well 24 for a side-connection to brush 26. FIG. 2 also shows that pocket 32 is defined, in-part, by a recessed, fixed-wall 38. FIG. 2 also shows the electrical terminals 20, each of which are connected to a respective RFI suppression circuit 30. In turn, each RFI circuit 30 is connected to an associated motor brush 26 by way of a respective flexible shunt wire 36. FIG. 3 is a perspective view of clip 14. Clip 14 is configured to be inserted into the bottom side of end cap body 12 to close the pockets 32, in a manner described in greater detail below. Clip 14 includes a base 40, a pair of axially-extending legs 42 each including a respective notch 44 on a distal end thereof, a pair of end walls 46, a pair of slot closure members 48 and a pair of key members 50. Clip 14 may comprise plastic material suitable for use in environments where exposure to fuel is contemplated. For example, acetal copolymer may be used for clip 14. The base 40 of clip 14 extends out in a generally semi-circular shape, in manner generally matched to the shape of the end cap body 12. The notch 44 on the end of each of the legs 42 may be generally concave and sized to capture the flexible shunt wire 36 when the clip 14 is inserted. To form a completely closed pocket 32, the clip 14 includes a number of enabling features. First, the notch 44 described above is configured to seal to the bottom of the pocket 32 upon full insertion of the clip 14. Second, the end wall 46 of clip 14 is configured to abut the fixed wall 38 of body 12 (best shown in FIG. 8). Third, the slot closure member 48 of clip 14 is configured to cover the slots 34 of body 12 (also best shown in FIG. 8). FIG. 4 shows the clip 14 in a partially inserted state relative to the end cap body 12. Note the key members 50 on clip 14 help orient the clip 14 correctly for insertion into the body 12. FIG. 4 also shows both of the slot closure members 48 (i.e., one the closure members 48 was obscured in FIG. 3). FIG. 5 shows the clip 14 fully inserted into the end cap body 12. FIG. 6 is a cross-sectional view taken substantially along lines 6-6 in FIG. 5. FIG. 6 shows that the pocket 32 becomes sealed when the clip 14 is fully inserted by virtue of a closure wall formed by leg 42. It should be appreciated that when the clip is fully inserted, the notch 44 not only captures flexible shunt wire 26 but also creates a seal against the floor 51 of the pocket 32. FIG. 7 is a cross-sectional view taken substantially along lines 7-7 in FIG. 5. FIG. 7 also shows the sealed pocket 32 that is created when the clip 14 is fully inserted in body 12. FIG. 7 additionally shows the side-connection 52 of the flexible shunt wire 36 to the brush 26. FIG. 7 also shows a pair of springs 52 that bias brushes 26 axially outwardly from brush wells 24. FIG. 8 is an enlarged view looking towards the bottom of the end cap body 12. First, FIG. 8 shows the electrical connections starting with the electrical terminal 20, which is then connected to RFI suppression circuit 30 by way a lead wire. RFI suppression circuit 30, in turn, is connected by a side-connection to brush 26 by the flexible shunt wire 36. In FIG. 8, the clip 14 is shown in dashed-line format, partially broken away, in order to allow a more clear illustration of the other features. In a further aspect of the invention, the end cap body 12 includes a first set of raised, axially-extending lands 56 configured to guide the insertion of one of the legs 42 into its pocket 32. A second set of raised, axially-extending lands 56 is preferably also present for help guide the other one of the legs 42 into its pocket 32. As also shown, the key 50 cooperates with a corresponding keying slot in the end cap body 12 to obtain the proper orientation of the clip 14 relative to the body 12. Also shown is the axially-extending end wall 46 of the clip 14 over-laid on and in registration with the fixed wall 38 of end cap body 12. Also shown is the slot closure member 48 over-laid on and in registration with the brush well slot 34. Finally, FIG. 8 also shows that the leg 42 acts as a closure wall, closing off and sealing pocket 32. The flexible shunt wire 36 is allowed to pass through the notch 44 (with, perhaps some compression), extending through pocket 32 and finally terminating with the side connection to brush 26 by passing below the covering slot closure member 48. FIG. 9 is a diagrammatic, simplified view of the present invention. FIG. 9 shows that the clip 14, particularly the notch 44, when inserted in a direction 58 indicated in the Figure into the end cap body 12, forms a seal with the shunt wire 36 against the floor of the pocket. The pocket 32 is thereafter electrically isolated isolated. The present invention provides a sealed pocket that is located adjacent to the motor brush well, and which contains and electrically isolates the flexible shunt wire. The occurrence of electrolysis is reduced or eliminated due to the highly resistive electrical path between either one of the flexible shunt wires and surfaces of opposite electrical polarity. The sealed pocket is formed by the mating surfaces of the end cap body (carrier) and the clip. The end cap body provides walls that form several sides of the pocket but allow for an open end which permits insertion of the shunt wire and the RFI suppression circuit termination wire during assembly. The mating clip completes the pocket wall by providing surfaces that seal any remaining openings. In an alternate embodiment, interlocking surfaces and/or a secondary gasket material may be used to improve the sealing between the mating surfaces. As is common to side-connected shunt wire-to-brush designs, a slot is provided on the side of the brush well to allow the shunt wire to travel with the brush movement. In alternate brush carrier designs, the spring end of the brush well is also sealed by the secondary clip. The top surface of the clip seals both the spring end of the brush bore and the top of the shunt pocket. Isolation legs extend perpendicularly downward from the top surface of the clip and fit into slotted keyways in the side of the shunt pocket walls upon inserting. The bottom ends of the isolation legs are concaved to fit with the shunt wire / inductor wire and form the lower seal with the shunt pocket. The top surface and isolation legs of the clip complete the walls needed to create an electrically isolated pocket for the shunt wire. These sealing surfaces could be enhanced by using a gasket material at the interface surfaces. The brush end of the well is sealed by a close running slip fit between the well inside diameter (ID) and the brush outside diameter (OD) profile. The sealed pocket design of the present invention also helps protect the shunt wire from corrosion by limiting the exposure to chemical agents found in fuels, such as sulfur. The sealed pocket minimizes or prevents replenishing of the chemical agent from the surrounding fuel. Accordingly, the concentration of any such corrosive chemical agent is reduced in the pocket volume and the corrosion is reduced or eliminated. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.
|
H
|
H02
|
H02K
|
5
|
00
|
|||
11858437
|
US20090079038A1-20090326
|
Method Of Making An Integrated Circuit Including Singulating A Semiconductor Wafer
|
ACCEPTED
|
20090311
|
20090326
|
[]
|
H01L23544
|
["H01L23544", "H01L2178"]
|
7674689
|
20070920
|
20100309
|
438
|
462000
|
72874.0
|
HOANG
|
QUOC
|
[{"inventor_name_last": "Schneegans", "inventor_name_first": "Manfred", "inventor_city": "Vaterstetten", "inventor_state": "", "inventor_country": "DE"}, {"inventor_name_last": "Kroninger", "inventor_name_first": "Werner", "inventor_city": "Regensburg", "inventor_state": "", "inventor_country": "DE"}]
|
A method of making an integrated circuit includes providing a semiconductor wafer having a first surface and a second surface opposite the first surface, at least one of the first surface and the second surface including a metallization layer deposited onto the surface. The method additionally includes forming a first trench in the semiconductor wafer extending from one of the first surface and the second surface toward an other of the first surface and the second surface. The method further includes sawing a second trench in the other surface until the second trench communicates with the first trench, thus singulating the integrated circuit from the semiconductor wafer.
|
1. A method of making an integrated circuit, the method comprising: providing a semiconductor wafer comprising a first surface and a second surface opposite the first surface, at least one of the first surface and the second surface including a metallization layer deposited onto the surface; forming a first trench in the semiconductor wafer extending from one of the first surface and the second surface toward an other of the first surface and the second surface; and sawing a second trench in the other of the first surface and the second surface until the second trench communicates with the first trench, thus singulating the integrated circuit from the semiconductor wafer. 2. The method of claim 1, wherein providing a semiconductor wafer comprises: providing a semiconductor wafer including a front side having an active chip surface, the front side coupled to a first carrier; grinding a side of the semiconductor wafer opposite the front side to define a back side of the semiconductor wafer; and depositing a metallization layer onto the back side. 3. The method of claim 2, wherein forming a first trench comprises: attaching the metallization layer to an adhesive carrier; decoupling the front side from the first carrier; and sawing the front side of the semiconductor wafer through a portion of the semiconductor wafer toward the back side to define dicing marks on the front side. 4. The method of claim 3, wherein sawing a second trench comprises: coupling the sawn front side of the semiconductor wafer to an adhesive carrier; matching the dicing marks on the front side with a desired saw pattern on the back side; and singulating a chip by sawing the back side of the semiconductor wafer. 5. The method of claim 3, wherein sawing the front side of the semiconductor wafer comprises transferring a saw pattern to the back side of the semiconductor wafer that is configured to visually guide sawing a second trench in the back side of the semiconductor wafer. 6. The method of claim 3, wherein decoupling the front side from the first carrier comprises cutting along a sloped cut line such that a diameter of the front side of the semiconductor wafer is greater than a diameter of the back side. 7. The method of claim 2, wherein forming a first trench comprises: removing an edge portion of the metallization layer; visualizing a front side kerf pattern by viewing through the removed edge portion of the metallization layer; aligning the metallization layer and the back side with the front side kerf pattern; and forming a first trench through the metallization layer and the back side of the semiconductor wafer, the first trench extending part way toward the front side of the semiconductor wafer. 8. The method of claim 7, wherein sawing a second trench comprises: coupling the metallization layer to an adhesive carrier; removing the first carrier from the front side of the semiconductor wafer; and sawing through the front side along the front side kerf. 9. The method of claim 7, wherein visualizing a front side kerf pattern comprises infrared viewing through the removed edge portion of the metallization layer to determine the front side kerf pattern. 10. The method of claim 2, wherein providing a semiconductor wafer comprises providing a semiconductor wafer having a thickness of about 700 micrometers and forming a first trench comprises sawing a first trench through the metallization layer and the back side of the semiconductor wafer, the first trench extending between about 50-100 micrometers toward the front side of the semiconductor wafer. 11. The method of claim 10, wherein sawing a second trench comprises: coupling the metallization layer to an adhesive carrier; and sawing through the front side along the front side kerf. 12. The method of claim 1, wherein a width of the first trench is greater than a width of the second trench. 13. The method of claim 1, wherein a width of the first trench is about equal to a width of the second trench. 14. A method of making an integrated circuit including singulating a semiconductor substrate, the method comprising: providing a semiconductor wafer comprising an active surface and a metallized back side opposite the active surface; sawing the active surface of the semiconductor wafer through a portion of the thickness of the semiconductor wafer; and dicing the semiconductor wafer by sawing the metallized back side through a remaining portion of the thickness of the semiconductor wafer. 15. The method of claim 14, wherein sawing the active surface of the semiconductor wafer comprises attaching the metallized back side to a carrier and sawing streets along a visible kerf pattern that is oriented between chips disposed on the active surface. 16. The method of claim 15, wherein dicing the semiconductor wafer comprises: attaching the sawn active surface to a carrier; and aligning the semiconductor wafer in a dicing tool such that the metallized back side is aligned with the sawn streets. 17. The method of claim 16, wherein attaching the metallized back side to a carrier comprises laser separating the semiconductor wafer from a carrier wafer such that a diameter of the active surface is greater than a diameter of the back side, the narrower back side configured to enable visualization of the sawn streets. 18. A method of making an integrated circuit including singulating a semiconductor substrate, the method comprising: providing a semiconductor wafer comprising an active surface and a metallized back side opposite the active surface; visualizing through the metallized back side to discern a kerf pattern on the active surface; sawing streets in the metallized back side that are aligned with the kerf pattern and extend part way toward the active surface; and sawing the active surface of the semiconductor wafer through a remaining thickness of the semiconductor wafer. 19. The method of claim 18, wherein visualizing through the metallized back side to discern a kerf pattern on the active surface comprises removing an edge portion of the metallized back side. 20. The method of claim 19, further comprising: infrared scanning through the removed edge portion of the metallized back side to identify the kerf pattern. 21. A semiconductor wafer having an active surface and a metallized back side opposite the active surface, the semiconductor wafer comprising: partially sawn first streets extending through the active surface and a portion of the thickness of the semiconductor wafer; means for aligning the metallized back side with a dicing tool such that the metallized back side is aligned with the first streets formed in the active surface; and second streets sawn into the metallized back side such that the second streets communicate with the first streets. 22. The singulated semiconductor substrate of claim 21, wherein means for aligning the metallized back side with a dicing tool comprises means for transferring visual information related to the sawn first streets on the active surface to the metallized back side. 23. The singulated semiconductor substrate of claim 22, wherein means for transferring visual information related to the sawn first streets on the active surface to the metallized back side comprises cutting a beveled edge around the semiconductor wafer such that a diameter of the active surface side of the semiconductor wafer is greater than a diameter of the metallized back side. 24. The singulated semiconductor substrate of claim 21, wherein the partially sawn first streets comprise streets half-cut diced into the active surface of the semiconductor wafer.
|
<SOH> BACKGROUND <EOH>Market demand for smaller and more functional electronic devices has driven the development of semiconductor devices, packages, and highly functional chips. Multiples of these functional chips are formed on a surface of a semiconductor wafer and include specific, desired chip properties. The semiconductor wafer includes a semiconductor substrate having a metal layer on one side and an active surface opposite the metal layer. The metal layer is configured to provide electrical connection for each chip after the chip is separated from the wafer. The active surface is fabricated to include contact pads that provide electrical access to the chip. After fabrication, the chips are cut or singulated from the semiconductor substrate and suited for individual use in electronic devices. FIG. 1 is a cross-sectional view of a conventional semiconductor substrate 20 . The known semiconductor substrate 20 includes a silicon portion 22 defining an active surface 24 , a back side 26 opposite active surface 24 , and a metal layer 28 deposited on back side 26 . Semiconductor substrate 20 is fabricated to include a plurality of chips (not shown) deposed in the plane of active surface 24 . After fabrication of semiconductor substrate 20 , it is desired to separate, or singulate, the individual chips by sawing semiconductor substrate 20 from active surface 24 down to back side 26 and through metal layer 28 . It is known that sawing through metal layer 28 is likely to produce burrs 30 , and/or cracks 32 . Burrs 30 and cracks 32 are highly undesirable. Burrs 30 extend from metal layer 28 and deleteriously affect electrical performance/contact of the chip when coupled to another electronic device. Cracks 32 can potentially interrupt the electrical contact between the silicon layer 22 and metal layer 28 . In addition, cracks 32 in silicon portion 22 are known to propagate when the chip is thermally cycled, thus possibly interrupting electrical connection for the chip. Dicing or cutting semiconductor substrate 20 from metal layer 28 through silicon layer 22 is problematic because the chip pattern (or kerf) on active surface 24 is not visible from the metal layer 28 side. Thus, blindly sawing semiconductor substrate 20 from metal layer 28 toward active surface 24 has the potential of damaging the unseen chips on active surface 24 . For these and other reasons there is a need for the present invention.
|
<SOH> SUMMARY <EOH>One aspect provides a method of making an integrated circuit. The method includes providing a semiconductor wafer having a first surface and a second surface opposite the first surface, at least one of the layers of the first surface and the second surface including a metallization layer deposited onto the surface. The method additionally includes forming a first trench in the semiconductor wafer extending from one of the first surface and the second surface toward another of the first surface and the second surface. The method further includes sawing a second trench in the other surface until the second trench communicates with the first trench, thus singulating the integrated circuit from the semiconductor wafer.
|
BACKGROUND Market demand for smaller and more functional electronic devices has driven the development of semiconductor devices, packages, and highly functional chips. Multiples of these functional chips are formed on a surface of a semiconductor wafer and include specific, desired chip properties. The semiconductor wafer includes a semiconductor substrate having a metal layer on one side and an active surface opposite the metal layer. The metal layer is configured to provide electrical connection for each chip after the chip is separated from the wafer. The active surface is fabricated to include contact pads that provide electrical access to the chip. After fabrication, the chips are cut or singulated from the semiconductor substrate and suited for individual use in electronic devices. FIG. 1 is a cross-sectional view of a conventional semiconductor substrate 20. The known semiconductor substrate 20 includes a silicon portion 22 defining an active surface 24, a back side 26 opposite active surface 24, and a metal layer 28 deposited on back side 26. Semiconductor substrate 20 is fabricated to include a plurality of chips (not shown) deposed in the plane of active surface 24. After fabrication of semiconductor substrate 20, it is desired to separate, or singulate, the individual chips by sawing semiconductor substrate 20 from active surface 24 down to back side 26 and through metal layer 28. It is known that sawing through metal layer 28 is likely to produce burrs 30, and/or cracks 32. Burrs 30 and cracks 32 are highly undesirable. Burrs 30 extend from metal layer 28 and deleteriously affect electrical performance/contact of the chip when coupled to another electronic device. Cracks 32 can potentially interrupt the electrical contact between the silicon layer 22 and metal layer 28. In addition, cracks 32 in silicon portion 22 are known to propagate when the chip is thermally cycled, thus possibly interrupting electrical connection for the chip. Dicing or cutting semiconductor substrate 20 from metal layer 28 through silicon layer 22 is problematic because the chip pattern (or kerf) on active surface 24 is not visible from the metal layer 28 side. Thus, blindly sawing semiconductor substrate 20 from metal layer 28 toward active surface 24 has the potential of damaging the unseen chips on active surface 24. For these and other reasons there is a need for the present invention. SUMMARY One aspect provides a method of making an integrated circuit. The method includes providing a semiconductor wafer having a first surface and a second surface opposite the first surface, at least one of the layers of the first surface and the second surface including a metallization layer deposited onto the surface. The method additionally includes forming a first trench in the semiconductor wafer extending from one of the first surface and the second surface toward another of the first surface and the second surface. The method further includes sawing a second trench in the other surface until the second trench communicates with the first trench, thus singulating the integrated circuit from the semiconductor wafer. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain principles of embodiments. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. FIG. 1 is a cross-sectional view of a semiconductor substrate as known in the art. FIG. 2 is a side view of a carrier assembly including a product wafer coupled to a carrier wafer according to one embodiment. FIG. 3 is a side view of the carrier assembly shown in FIG. 2 after the product wafer has been ground and coated with a metallization layer to define a semiconductor substrate according to one embodiment. FIG. 4 is a side view of the semiconductor substrate shown in FIG. 3 coupled to an adhesive carrier according to one embodiment. FIG. 5 is a side view of the semiconductor substrate shown in FIG. 4 illustrating a diced active surface according to one embodiment. FIG. 6 is a back side view of exposed and un-diced metallization layer with the diced active surface of the semiconductor substrate mounted to another adhesive carrier according to one embodiment. FIG. 7A is a back side view after dicing of the metallization layer shown in FIG. 6. FIG. 7B is side view of singulated semiconductor chips coupled to a tape carrier according to one embodiment. FIG. 8A is a side view of a semiconductor substrate mounted on a carrier according to another embodiment. FIG. 8B is a side view of a dicing blade sawing a trench through a metalized back side of the semiconductor substrate shown in FIG. 8A. FIG. 8C is a side view of the sawn metalized back side illustrated in FIG. 8B mounted on a film of a clamp assembly. FIG. 8D is a side view showing removal of the carrier illustrated in FIG. 8A. FIG. 8E is a side view showing a dicing blade cutting a trench into an active surface of the semiconductor substrate shown in FIG. 8A according to one embodiment. FIG. 9A is a side view of a thick semiconductor substrate oriented metallization layer up according to one embodiment. FIG. 9B is a side view of a first trench cut through the metallization layer of the semiconductor substrate shown in FIG. 9A. FIG. 9C is a side view of a second trench cut into an active surface of the semiconductor substrate shown in FIG. 9A. DETAILED DESCRIPTION In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. It is to be understood that the features of the various exemplary embodiments described herein may be combined with each other, unless specifically noted otherwise. As employed in this Specification, the terms “coupled” and/or “electrically coupled” are not meant to mean that the elements must be directly coupled together; intervening elements may be provided between the “coupled” or “electrically coupled” elements. Embodiments provide a method of sawing a semiconductor substrate including a silicon wafer portion and a metal layer portion that minimizes or eliminates the formation of burrs and/or cracks when sawing through the semiconductor substrate. Some embodiments provide for the partial dicing through a semiconductor substrate. Dicing part way through the substrate, for example through an active surface of the semiconductor substrate, provides an alignment feature that enables full-thickness dicing of the substrate through a metallized back side. In one embodiment, the partial dicing alignment feature aligns enables alignment of the metallized back side with kerf lines/dicing lines formed on the active surface of the semiconductor substrate. In this manner, final dicing streets that are cut through the metallization layer align with the partial/initial dicing streets sawn through the active surface of the semiconductor substrate. Other embodiments provide for the removal of a portion of a metallization layer deposited on a back side of a semiconductor substrate, where the removed portion of the metallization layer enables optical alignment of the metallized back side with kerf lines on an opposing active surface of the semiconductor substrate. To this end, the back side metallization layer is first sawn in alignment with the kerfs on the active surface, and a second subsequent sawing of the active surface singulates chips from the semiconductor substrate. In other embodiments, first trenches or streets are diced in a first surface of the semiconductor substrate, where the first streets imprint or otherwise transfer a cutting pattern to the opposite surface of the semiconductor substrate. Thereafter, the imprinted surface of the semiconductor substrate may be accurately sawn in alignment with the first streets. The various embodiments of partial dicing of streets in a semiconductor substrate solves the problem known in the art of forming metal burrs when the semiconductor substrate is diced from the kerf lines on the active surface down to the metallization layer. In addition, the partial dicing of streets in a semiconductor substrate as described herein minimizes or eliminates the undesirable formation of cracks in the silicon portion of the substrate. FIG. 2 is a side view of a carrier assembly 50 according to one embodiment. Carrier assembly 50 includes a semiconductor substrate 52 having an active surface 54, where semiconductor substrate 52 is coupled to a carrier wafer 56 by adhesive 58. Semiconductor substrate 52 includes silicon wafers having a diameter of about 100 to about 300 millimeters. In one embodiment, semiconductor substrate 52 is provided as a thick product wafer having semiconductor chips (not shown) formed on active surface 54. Active surface 54 of semiconductor substrate 52 is oriented toward carrier wafer 56. The chips are aligned in rows and columns across active surface 54, where the space between the rows and columns of chips define a kerf pattern (not shown). Subsequent to fabrication, the chips are singulated from semiconductor substrate 52 by sawing or dicing along the kerf to provide individual chips useful in electronic components. Carrier wafer 56 is coupled over active surface 54 by glue 58. In one embodiment, carrier wafer 56 is a thin silicon carrier wafer configured to protect active surface 54 during fabrication of semiconductor substrate 52. In one embodiment, an outer perimeter of semiconductor substrate 52 is coupled to an outer perimeter of carrier wafer 56 by adhesive material 58. Adhesive material 58 includes epoxies, glues, and other materials suited for adhesively coupling carrier wafer 56 to product wafer 52. FIG. 3 is a side view of carrier assembly 50 illustrating semiconductor substrate 52 after thinning according to one embodiment. In one embodiment, semiconductor substrate 52 is ground to reduce its thickness, which defines a back side 60 opposite active surface 54. In one embodiment, a metallization layer 62 is deposited onto back side 60 of semiconductor substrate 52, such that semiconductor substrate 52 includes active surface 54 and a metal layer 62 opposite active surface 54. In one embodiment, semiconductor substrate 52 is thinned by grinding to have a thickness T of between about 40-60 micrometers, although other thicknesses are also acceptable. In one embodiment, metallization layer 62 is deposited onto back side 60 to have a thickness of between about 1-8 micrometers. Metallization layer 62 is deposited in a suitable deposition process, including a vapor deposition process, a chemical vapor deposition process, a plasma vapor deposition process, sputtering, or other suitable deposition process employed to coat a thin layer of metal 62 onto back side 60 of semiconductor substrate 52. FIG. 4 is a side view of carrier assembly 50 coupled to a carrier tape 70 according to one embodiment. In one embodiment, metallization layer 62 is coupled to carrier tape 70 and active surface 54 is oriented toward carrier wafer 56. In one embodiment, carrier tape 70 is a single sided adhesive tape configured to carry semiconductor substrate 52 through fabrication processes. In another embodiment, carrier tape 70 is a saw foil 70, although other forms of tape are also acceptable. In one embodiment, a separation line 72 is provided that removes carrier wafer 56 from semiconductor substrate 52 by cutting within the perimeter of adhesive 58. In one embodiment, separation line 72 is provided by a laser or other energetic cutting procedure in which a cut is provided to remove carrier wafer 56 from carrier assembly 50. In one embodiment, separation line 72 is oriented at an angle A relative to vertical such that separation line 72 is a sloped cutting line and semiconductor substrate 52 includes beveled edges. In one embodiment, separation line 72 does not sever carrier tape 70, such that carrier tape 70 is available for subsequent fabrication of semiconductor substrate 52. FIG. 5 is a side view of semiconductor substrate 52 after the removal of carrier wafer 56 (FIG. 4) from carrier assembly 50. Angled separation line 72 (FIG. 4) severs semiconductor substrate 52 such that active surface 54 has a first diameter D1 and metallization layer 62 has a second diameter D2. In one embodiment, D1 is greater than D2 such that semiconductor substrate 52 is beveled in a manner that active surface 54 extends beyond metallization layer 62. In one embodiment, semiconductor substrate 52 is oriented on carrier tape 70 such that active surface 54 is oriented up (relative to FIG. 5) and configured for dicing or sawing by a dicing blade. As noted above, active surface 54 includes a plurality of semiconductor chips oriented in columns and rows, where the chips are separated by a kerf. The layout of the chips, and the kerf, is visible on active surface 54. Sawing along the kerf ensures accurate singulation of semiconductor substrate 52. However, sawing along the kerf from active surface 54 down to metallization layer 62 has the potential to form undesirable metal burrs and cracks in the silicon wafer. In one embodiment, a plurality of first trenches 80 are formed in active surface 54 that dice or extend partially into the thickness of semiconductor substrate 52. In one embodiment, first trenches 80 are half-cut diced into active surface 54 and extend part-way toward metallization layer 62. In this specification, half-cut dice means a cut street that extends between 10-90% of the thickness of semiconductor substrate 52. In some embodiments, a half-cut diced street extends about midway through semiconductor substrate 52, although first trenches 80 could extend more than 50% or less than 50% through semiconductor substrate 52 consistent with the definition of half-cut diced. In one embodiment, sawing front side active surface 54 of semiconductor wafer substrate 52 transfers a saw pattern to back side 60 of semiconductor wafer substrate 52 and/or metallization layer 62 that is configured to visually guide sawing second trenches in back side 60 of the semiconductor wafer substrate 52. As described below, half-cut dicing of the front/active surface 54 enables matching the dicing marks on the active surface 54 with a desired saw pattern on the back side or metallization layer 62. FIG. 6 is a back side view of metallization layer 62 showing active surface 54 of semiconductor substrate 52 coupled to another adhesive carrier 71. Metallization layer 62 is exposed (oriented up relative to FIG. 6) and prevents the optical, infrared or otherwise, visualization of first trenches 80. Active surface 54 including first trenches 80 has been coupled to adhesive carrier 71. Active surface 54 has a diameter D1 that is larger than diameter D2 of metallization layer 62. In this manner, first trenches 80 formed an active surface 54 are visible around a periphery 82 of metallization layer 62. In one embodiment, the visible first trenches 80 disposed around and extending beyond the periphery 82 of metallization layer 62 enables alignment of metallization layer 62 along a direction of first trenches 80. In this manner, a dicing tool is aligned with and enabled to cut/dice a second set of trenches that will align with first trenches 80. In one embodiment, beveled separation line 72 (FIG. 4) is configured such that diameter D1 is greater than diameter D2 and thus provides a transfer alignment mechanism that enables metallization layer 62 to be aligned with first trenches 80 prior to cutting of second trenches in metallization layer 62. For example, in one embodiment an X-Y axis 84 of semiconductor substrate 52 is spatially oriented such that metallization layer 62 is aligned with first trenches 80 and with a desired cutting direction for second trenches. FIG. 7A is a back side view of semiconductor substrate 52 including second trenches 90 cut into metallization layer 62 in alignment with first trenches 80. FIG. 7B is a side view of semiconductor substrate 52 including singulated chips 92 according to one embodiment. In one embodiment, active surface 54 is in contact with carrier tape 71 and metallization layer 62 is oriented up relative to the illustration of FIG. 7B. First trenches 80 and second trenches 90 align and intersect such that chips 92 are singulated from semiconductor substrate 52 and retained by transfer tape 71. Chips 92 are coupled to transfer tape 71 in a manner that enables transportation and subsequent mounting of chips 92 to other electronic devices. FIG. 8A is a side view of a semiconductor carrier assembly 100 according to another embodiment. Semiconductor carrier assembly 100 includes a semiconductor substrate 102 coupled to a carrier 104. In one embodiment, semiconductor substrate 102 is coupled to carrier 104 by an adhesive deposited about a periphery 106 of assembly 100, although other forms of coupling substrate 102 to carrier 104 are also acceptable. In one embodiment, semiconductor substrate 102 includes a wafer 108 having an active surface 110 opposite a back side 112 and a metallization layer 114 coupled to back side 112. It is desired to dice or singulate semiconductor substrate 102 by cutting through metallization layer 114. However, metallization layer 114 forms an optical barrier to visualizing the kerf pattern on active surface 110 of semiconductor substrate 102. In addition, the metal of metallization layer 114 prevents other forms of optical visualization of active surface 110, including infrared imaging through semiconductor 102. FIG. 8B is a side view of semiconductor carrier assembly 100 including a dicing blade 120 oriented along the kerf pattern on active surface 110 of semiconductor substrate 102. In one embodiment, an edge portion 122 of metallization layer 114 is removed from semiconductor substrate 102. Removal of edge portion 122 enables visualization of at least a portion of the kerf pattern on active surface 110, which enables alignment of dicing blade 120 between the chips formed on active surface 11 0. For example, in one embodiment infrared imaging is projected through the edge portion 122 and through silicon wafer 108 to provide a view of a portion of the front side kerf pattern formed on active surface 110. Thereafter, semiconductor substrate 102 is aligned such that dicing blade 120 is oriented along the visualized kerf pattern on the active surface 110. Dicing blade 120 dices or cuts a set of first trenches 124 through metallization layer 114 and through a portion of silicon wafer 108. First trenches 124 are half-cut diced through semiconductor substrate 102 such that metallization layer 114 is diced first, which has been found to minimize or eliminate the formation of metal burrs. FIG. 8C is a side view of semiconductor carrier assembly 100 coupled to a clamp assembly 130 according to one embodiment. In one embodiment, metallization layer 114 is adhesively coupled to a flexible film 132 of clamp assembly 130 such that carrier 104 is oriented upwards. FIG. 8D is a side view of carrier assembly 100 shown in FIG. 8C. In one embodiment, a cut line 134 is formed along the edge of semiconductor substrate 102 such that adhesive 106 at the periphery of assembly 100 is removed/separated. In one embodiment, a cut line 134 is formed by laser cutting, although other forms of providing cut line 134 are also acceptable. After cut line 134 is provided on assembly 100, carrier 104 is removed from semiconductor substrate 102 to expose active surface 110. FIG. 8E is a side view of semiconductor substrate 102 coupled to film 132 of clamp 130. Active surface 110 is oriented up and the chips and kerf on active surface are visible. First trenches 124 diced into metallization layer 114 are oriented down adjacent to film 132. In one embodiment, a wide dicing blade 140a dices a street along kerf of active surface 110 of semiconductor substrate 102 to form second trenches 144a that are aligned with first trenches 124. In one embodiment, wide dicing blade 140a has a width of between about 50-70 micrometers, preferably the width of wide dicing blade 140a is about 60 micrometers. In another embodiment, a thin dicing blade 140b dices a street along kerf of active surface 110 of semiconductor substrate 102 to form second trenches 144b that are aligned with first trenches 124. In one embodiment, thin dicing blade 140b has a width of between about 10-30 micrometers, and preferably thin dicing blade 140b has a width of about 20 micrometers. Although both dicing blades 140a, 140b are illustrated, it is to be understood that dicing of semiconductor substrate 102 is accomplished by employing one of the illustrated dicing blades. Embodiments provided above in FIGS. 8A-8E provide half-cut dicing part way into a metallized back side of a semiconductor substrate with a process that reduces or eliminates the formation of metal burrs. Cutting first trenches 124 into metallization layer 114 provides an efficient process for singulating chips from a semiconductor substrate that saves at least one processing step. FIG. 9A is a side view of a thick semiconductor substrate 150 according to another embodiment. Semiconductor substrate 150 includes a silicon wafer 152 including an active surface 154 opposite a back side 156 and a metallization layer 158 coupled to back side 156. In one embodiment, semiconductor substrate 150 has a thickness H of between about 600-800 micrometers, and typically semiconductor substrate 150 has a thickness H of about 725 micrometers. In one embodiment, semiconductor substrate 150 is half-cut diced through metallization layer 158 in a manner that minimizes or eliminates the formation of metal burrs and/or cracks in silicon wafer 152. FIG. 9B is a side view of semiconductor substrate 150 including an edge portion 162 of metallization layer 158 that has been removed to enable visualization of a front side kerf formed on active surface 154. In one embodiment, edge portion 162 of metallization layer 158 is removed down to back side 156 to enable infrared visualization of the front side kerf formed on active surface 154. In this manner, a dicing blade 170 is oriented relative to metallization layer 158 and in alignment with front side kerf on active surface 154, which enables alignment for cutting of a first set of trenches. In one embodiment, a dicing blade 170 half-cut dices a set of first trenches 172 through metallization layer 158 and into a portion of silicon wafer 152. In one embodiment, first trenches 172 are diced through metallization layer 158 to a thickness of H1. In one embodiment, thickness H1 of first trenches 172 has a depth of between about 50-100 micrometers leaving a solid thickness H2 of silicon wafer 152. In one embodiment, thickness H2 provides stable silicon having a thickness of about 600 micrometers. FIG. 9C is a side view of semiconductor substrate 150 coupled to a thin film 182 of clamp 180. In one embodiment, metallization layer 158 is coupled to thin film 182 and active surface 154 including the visible front side kerf is oriented up. In one embodiment, a relatively thick and stable portion of silicon wafer 152 remains and is presented for dicing and singulation. In one embodiment, silicon wafer 152 has a thickness H2 of silicon that is easily diced by dicing blades 190a, 190b in a manner that resists cracking. In one embodiment, H2 has a thickness of between about 550-650 micrometers. In one embodiment, a thick dicing blade 190a dices a street along kerf of active surface 154 of silicon wafer 152 to form a second set of trenches 192a that align and intersect with first streets/trenches 172. Thick dicing blade 190a follows the front side kerf that is visible on active surface 154 and cuts streets 192a down to at least a thickness H2 such that second trenches 192a align with and meet first trenches 172. In one embodiment, thick dicing blade 190a is similar to wide dicing blade 140a (FIG. 8E) and has a width of about 60 micrometers. In another embodiment, a thin dicing blade 190b dices a street along kerf of active surface 154 of silicon wafer 152 to form second trenches 192b through silicon wafer 152. In one embodiment, thin dicing blade 190b is similar to thin dicing blade 140b (FIG. 8E) and has a thickness of about between 10-30 micrometers and is employed to cut a set of second trenches 192b through at least the thickness H2. Second trenches 192b are aligned and cut through first trenches 172 to singulate chips from semiconductor substrate 150. Embodiments provide the singulation a semiconductor substrate by aligning the un-diced metallized back side accurately with streets half-cut diced in the active side of a semiconductor substrate. In some embodiments, streets cut onto one side of the semiconductor substrate are transferred and aligned with the other, opposite side of the semiconductor substrate. Other embodiments provide cutting a first set of trenches into a semiconductor substrate through the metallized back side in a manner that minimizes or eliminates the formation and propagation of cracks through the silicon and minimizes or eliminates the creation of metal burrs. In one embodiment, an active surface of a semiconductor substrate is half-cut diced with first trenches that imprint a pattern onto a metallized back side. The imprinted pattern on the back side is subsequently aligned and diced with streets to singulate chips from the semiconductor substrate. In other embodiments, a portion of the metallized back side is removed to enable visual alignment of the metallized back side with the front side kerf. A first set of trenches is formed in the metallized back side with a minimum formation of burrs. A second set of trenches is formed in the active surface of the semiconductor substrate, where the second streets/trenches align with the first trenches cut through the metallized back side. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments that provide a method of sawing a semiconductor substrate. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
|
H
|
H01
|
H01L
|
235
|
44
|
|||
11840817
|
US20080043109A1-20080221
|
APPARATUS AND METHOD FOR DATA TRANSMISSION/RECEPTION
|
ACCEPTED
|
20080206
|
20080221
|
[]
|
H04N5225
|
["H04N5225"]
|
8059181
|
20070817
|
20111115
|
348
|
333010
|
97956.0
|
TREHAN
|
AKSHAY
|
[{"inventor_name_last": "SIM", "inventor_name_first": "Dae-Hyun", "inventor_city": "Seoul", "inventor_state": "", "inventor_country": "KR"}]
|
Disclosed is an apparatus and method for data transmission/reception for transmitting/receiving data, which can transmit and receive data by using a transmitter (display device) capable of receiving and displaying digital data, and a receiver capable of receiving digital data by photographing the digital data. The apparatus includes a transmitter for receiving and displaying digital data; and a receiver for photographing and receiving the digital data displayed in the transmitter, and restoring the received digital data, thereby restoring corresponding data information. The method includes receiving and displaying digital data by a transmitter; and photographing and receiving the digital data displayed in the transmitter, and restoring the received digital data and displaying a corresponding data by a receiver.
|
1. An apparatus for data transmission/reception, the apparatus comprising: a transmitter for receiving and displaying digital data; and a receiver for photographing and receiving the digital data displayed in the transmitter, and restoring corresponding data information by restoring the received digital data. 2. The apparatus of claim 1, further comprising a data service providing unit for transferring the digital data frame-by-frame to the transmitter. 3. The apparatus of claim 2, wherein each of the frames of the digital data includes at least one data channel, each of the data channels including corresponding channel information. 4. The apparatus of claim 1, wherein the transmitter comprises: a receiving unit for receiving the digital data; an image buffer for storing the digital data frame-by-frame, in which a frame of the digital data includes at least one data channel and control signal information is contained in a corresponding frame of the digital data a display unit for displaying the corresponding frame of the digital data stored in the image buffer; and a control unit for creating control signal information from frame information contained in the corresponding frame of the digital data, controlling storage of the digital data frame-by-frame in the image buffer and controlling display of the corresponding frame of the digital data stored in the image buffer on the display unit, each of the frames of the digital data includes at least one data channel frame and containing the control signal information. 5. The apparatus of claim 4, wherein the control unit creates the control signal information including an intensity calibration signal, a tilt calibration signal and a synchronizing signal, and stores the control signal information in the corresponding frame at predetermined positions, wherein the intensity calibration signal is used to calibrate intensity of pixel data of the corresponding frame of the digital data photographed by the receiver, and the tilt calibration signal is used to calibrate tilt of the corresponding frame of the digital data photographed by the receiver, and the synchronizing signal is used to indicate a number of the corresponding frame of the digital data photographed by the receiver. 6. The apparatus of claim 1, wherein the receiver comprises: a camera unit for photographing the digital data displayed in the transmitter; an image processing unit for restoring a corresponding frame of the digital data photographed by the camera unit and output corresponding data information of the corresponding frame of the digital data into a display unit; and a control unit extracting control signal information contained in the corresponding frame of the digital data when the corresponding frame of the digital data photographed by the camera is received, calibrating the corresponding frame, and controlling restoration of the corresponding frame and display of the corresponding data information of the corresponding frame on the display unit. 7. The apparatus of claim 6, wherein the control unit calibrates pixel data values of the corresponding frame into predetermined values using an intensity signal in the control signal information when the pixel data values of the corresponding frame are different from pixel data values of the intensity calibration signal in the control signal information; the control unit extracts a degree of tilt of the corresponding frame and calibrates the tilt of the corresponding frame using a tilt calibration signal in the control signal information when a size of the corresponding frame is out of at least one reference value of the tilt calibration signal; and the control unit extracts a number of the corresponding frame using a synchronizing signal in the control signal information. 8. The apparatus of claim 1, wherein the transmitter is a display device capable of displaying the received digital data, and the receiver is a portable terminal including a digital camera unit. 9. A method for data transmission/reception, the method comprising: receiving and displaying digital data by a transmitter; and photographing and receiving the digital data displayed in the transmitter, and restoring the received digital data and displaying corresponding data of the received digital data by a receiver. 10. The method of claim 9, wherein receiving and displaying the digital data by the transmitter further comprises: receiving a corresponding frame of the digital data, the corresponding fame including at least one data channel; creating control signal information from frame information stored in the corresponding frame of the digital data; causing the control signal information to be contained and stored in the corresponding frame of the digital data; and outputting and displaying the corresponding frame of the digital data containing the control signal information. 11. The method of claim 10, wherein creating the control signal information further comprises: creating an intensity calibration signal of the control signal information from the frame information stored in the corresponding frame of the digital data, and storing the intensity calibration signal at a predetermined position of the corresponding frame; creating a tilt calibration signal of the control signal information from the frame information stored in the corresponding frame of the digital data, and storing the tilt calibration signal at a predetermined position of the corresponding frame; and creating a synchronizing signal of the control signal information from the frame information stored in the corresponding frame of the digital data, and storing the synchronizing signal at a predetermined position of the corresponding frame. 12. The method of claim 9, wherein displaying the corresponding data of the received digital data by the receiver further comprises: photographing and receiving, by the receiver, the digital data displayed in the transmitter; calibrating the corresponding frame of the received digital data using the control signal information; and restoring the corresponding frame of the calibrated digital data and displaying corresponding data information of the corresponding frame. 13. The method of claim 12, wherein calibrating the corresponding frame of the received digital data using the control signal information further comprises: extracting the control signal information stored in the corresponding frame of the received digital data; calibrating pixel data of the corresponding frame into predetermined values using an intensity calibration signal of the control signal information when pixel data values of the corresponding frame are different from pixel data values of the intensity calibration signal; extracting a degree of tilt of the corresponding frame and calibrating the tilt of the corresponding frame using an tilt calibration signal of the control signal information when a size of the corresponding frame is out of at least one reference value of the tilt calibration signal; and extracting a number of the corresponding frame using a synchronizing signal of the control signal information. 14. The method of claim 9, wherein the transmitter is a display device capable of displaying received digital data, and the receiver is a portable terminal including a digital camera unit.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to an apparatus and method for data transmission/reception, and in particular, to an apparatus and method for transmitting and receiving data using a transmitter (display device) capable of receiving and displaying digital data and a receiver capable of receiving digital data by photographing the digital data. 2. Description of the Related Art Recently, the portable terminal has been developed to include a high-speed data transmission function as well as a voice communication function. Moreover, most of today's portable terminals also include a camera which is capable of photographing image data. Typically, the cameras added to the portable terminal are digital cameras. However, if, by using the added camera, the portable terminal can receive and process data of a digital signal as well as photographing the image data, it is possible to receive high speed data at a distance within which the camera can take a photograph.
|
<SOH> SUMMARY OF THE INVENTION <EOH>An aspect of the present invention is to substantially solve the above-mentioned problems occurring in the prior art and to provide at least the advantages described below. Accordingly, the present invention provides an apparatus and method for data transmission/reception, which can transmit and receive data using a transmitter (display device) capable of receiving and displaying digital data and a receiver capable of receiving digital data by photographing the digital data. According to an aspect of the present invention, there is provided an apparatus for data transmission/reception. The apparatus includes a transmitter for receiving and displaying digital data; and a receiver for photographing and receiving digital data displayed in the transmitter and restoring corresponding data information by restoring the received digital data. According to another aspect of the present invention, there is provided a method for data transmission/reception. The method includes receiving and displaying digital data by a transmitter; and photographing and receiving the digital data displayed in the transmitter, and restoring the received digital data and displaying corresponding data of the received digital data by a receiver.
|
PRIORITY This application claims priority under 35 U.S.C. §119(a) to a Korean Patent Application entitled “Apparatus and Method For Data Transmission/Reception” filed with the Korean Intellectual Property Office on Aug. 17, 2006 and assigned Serial No. 2006-77581, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to an apparatus and method for data transmission/reception, and in particular, to an apparatus and method for transmitting and receiving data using a transmitter (display device) capable of receiving and displaying digital data and a receiver capable of receiving digital data by photographing the digital data. 2. Description of the Related Art Recently, the portable terminal has been developed to include a high-speed data transmission function as well as a voice communication function. Moreover, most of today's portable terminals also include a camera which is capable of photographing image data. Typically, the cameras added to the portable terminal are digital cameras. However, if, by using the added camera, the portable terminal can receive and process data of a digital signal as well as photographing the image data, it is possible to receive high speed data at a distance within which the camera can take a photograph. SUMMARY OF THE INVENTION An aspect of the present invention is to substantially solve the above-mentioned problems occurring in the prior art and to provide at least the advantages described below. Accordingly, the present invention provides an apparatus and method for data transmission/reception, which can transmit and receive data using a transmitter (display device) capable of receiving and displaying digital data and a receiver capable of receiving digital data by photographing the digital data. According to an aspect of the present invention, there is provided an apparatus for data transmission/reception. The apparatus includes a transmitter for receiving and displaying digital data; and a receiver for photographing and receiving digital data displayed in the transmitter and restoring corresponding data information by restoring the received digital data. According to another aspect of the present invention, there is provided a method for data transmission/reception. The method includes receiving and displaying digital data by a transmitter; and photographing and receiving the digital data displayed in the transmitter, and restoring the received digital data and displaying corresponding data of the received digital data by a receiver. BRIEF DESCRIPTION OF THE DRAWINGS The above and other exemplary features, aspects, and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a block diagram illustrating data transmission/reception according to the present invention; FIG. 2 is a view illustrating a configuration of a corresponding frame of digital data displayed in the transmitter of FIG. 1; FIG. 3 is a block diagram illustrating a structure of the receiver of FIG. 1; and FIG. 4 is a flowchart illustrating a process for data transmission/reception according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals represent like parts throughout the drawings. FIG. 1 is a block diagram illustrating a data transmission/reception in accordance with an embodiment of the present invention. In an embodiment of the present invention, it is assumed that a transmitter is a display device which can receive and display digital data, and a receiver is a portable terminal which can photograph digital data, thereby receiving the digital data. In FIG. 1, a data service providing unit 300 transfers data, such as digital broadcast data, news, information of weather forecast and traffic, etc., to a display device 200 in the form of compressed digital data. The data service providing unit 300 may compress the data using an audio codec such as H.264 and a video codec such as MPEG 4, and transfers the compressed data to the display device 200 in a transfer format in an existing transfer mode of handheld broadcast, such as Real-Time Streaming or File-Delivery, etc. Further, the data service providing unit 300 transfers the digital data to the display device 200 frame by frame, and each of frames of the digital data transferred frame by frame includes at least one data channel. Each data channel contains corresponding channel information. Each of the frames contains configuration information for the data channel, namely, frame information which includes values of pixel positions at which corresponding data channels are stored in the entire frame, display information for displaying the frame on the display device 200, frame size information, etc. The display device 200 displays input digital data. The display device 200 may be installed in an outdoor/indoor space, at home, in the office, in an automobile, etc., and may have resolution capable of resolving the pixel number of a digital camera of Video Graphics Array/Super Video Graphics Array/Extended Graphics Array (VGA/SVGA/XGA) grade, etc. The display device 200 receives and displays the digital data received frame by frame from the data service providing unit 300. That is, the display device 200 receives and displays a corresponding frame of the digital data including at least one piece of data information. In the display device 200, a receiving unit 210 receives the corresponding frame of digital data from the data service providing unit 300 over wireless communication frame-by-frame. Here, the received corresponding frame includes the frame information containing at least one data channel, the configuration information for the data channel, display information for displaying the frame on the display device 200, frame size information, etc. An image buffer 220 stores the received digital data frame-by-frame in which control signal information is contained in a corresponding frame, and outputs the corresponding frame containing the control signal information to a first display unit 230. The first display unit 230 displays a corresponding frame of the digital data stored in the image buffer 220, which contains control signals. Since the digital data displayed on the first display unit 230 is not normal image data but data for wireless communication, the data is not visible image data which can be recognized by the naked eye. FIG. 2 shows a corresponding frame of digital data stored in the image buffer 220, which contains the control signals such as an intensity calibration signal, a tilt calibration signal, and a synchronizing signal. In FIG. 2, an intensity reference row corresponds to predetermined positions where pixel data values corresponding to the intensity calibration signal are stored. A first reference value to a fourth reference value correspond to reference values used to extract a degree of tilt of the corresponding frame and to calibrate tilt of the corresponding frame. A synchronizing reference line corresponds to a predetermined position at which the synchronizing signal for indicating a number of the corresponding frame is stored. The channel information indicates a pixel position value at which at least one piece of channel information contained in one frame is stored. The intensity calibration signal, the tilt calibration signal and the synchronizing signal, which are the control signals of FIG. 2, will be described below in detail for operation of a first control unit 240. The first control unit 240 controls the general operation of the display unit 200. The first control unit 240 creates the control signal information from the frame information stored in a corresponding frame of the digital data received through the receiving unit 210. Under the control of the first control unit 240, the image buffer 220 stores the digital data frame-by-frame, in which the control signal information is contained in a corresponding frame of the digital data. On the other hand, under the control of the first control unit 240, the first display unit 230 displays a corresponding frame of the digital data stored in the image buffer 220, which contains the control signal information. At this time, under the control of the first control unit 240, the first display unit 230 displays the corresponding frame based on the display information of the frame information stored in the corresponding frame. The display information includes data information (e.g., RGB/YUV) for displaying the corresponding frame on the first display unit 230, horizontal/vertical sync information and pixel clock information. The first control unit 240 creates the control signal information including the intensity calibration signal, the tilt calibration signal and the synchronizing signal, from the frame information stored in the corresponding frame. FIG. 2 shows the configuration for the corresponding frame of the digital data displayed on the first display unit 230. In FIG. 2, the intensity calibration signal, the tilt calibration signal and the synchronizing signal will be now described. The intensity calibration signal, which is used to calibrate the intensity of pixel data of the corresponding frame of the digital data photographed by the portable terminal 100, is stored with the same predetermined pixel values at predetermined positions of the corresponding frame. For example, as shown in FIG. 2, if the size of the corresponding frame is 640*480, a middle pixel row between (238, 0) and (238, 639) is referred to as the intensity reference row (predetermined positions) for storing the intensity calibration signal, and the predetermined pixel values which are middle values of each of RGB are equally stored at the predetermined positions as pixel data values of the intensity calibration signal. Accordingly, when the portable terminal 100 receives the corresponding frame, actual values of pixel data located in (238, 0)−(238, 639), which are the predetermined positions at which the intensity calibration signal is stored, are compared with the values of the pixel data corresponding to the intensity calibration signal. If the values are different from each other, an error has occurred in the entire pixel data of the corresponding frame. Then, an intensity calibration of the entire pixel data is carried out. The intensity calibration may be performed in a manner where extracted values, which are obtained by dividing the pixel data values of the intensity calibration signal by the actual pixel data values, are added pixel data values located in the corresponding row, respectively. The tilt calibration signal is used to calibrate the tilt of the photographed corresponding frame when the portable terminal 100 is tilted out of level or is blurred during photographing the digital data displayed in the display device 200. The tilt calibration signal has at least one reference value. When the size of the corresponding frame is out of the reference value, the corresponding frame is determined as being tilted, and tilt information of the corresponding frame is extracted, by which the tilt of the frame is then calibrated. For example, as shown in FIG. 2, if the size of the corresponding frame is 640*480, the tilt calibration signal may have at least one reference value of a first reference value (1˜n, 0), a second reference value (1˜n, 639), a third reference value (479-n˜479, 0) and a fourth reference value (479-n˜479, 639). In a case in which the tilt calibration signal has the first—fourth reference values, if the corresponding frame is out of positions corresponding to the reference values, the corresponding frame is determined as being tilted. The degree of tilt of the corresponding frame is then extracted. The corresponding pixel values located at positions corresponding to the degree of the tilt are used to calibrate the degree of the tilt. The frame with pixel values of the calibrated positions is then output and displayed again. The synchronizing signal indicates the number of the corresponding frame of the digital data photographed by the portable terminal 100. The synchronizing signal is stored, as shown FIG. 2, at (n+1˜479-n,0) which are predetermined positions of the corresponding frame with predetermined pixel values. The portable terminal 100 receives digital data displayed in the display device 200 by photographing it, and restores the received digital data and displays corresponding data information. A configuration of the portable terminal 100 will be described in detail with reference to FIG.3. FIG. 3 shows the configuration of the portable terminal 100 according to an embodiment of the present invention. In FIG. 3, an Radio Frequency (RF) unit 123 performs wireless communication. The RF unit 123 includes a RF transmitter for up-converting and amplifying the frequency of a signal to be transmitted, and an RF receiver for low-noise amplifying and down-converting the frequency of a signal to be received. A modem 120 includes a transmitter for encoding and modulating the signal to be transmitted and a receiver for demodulating and decoding the signal to be received. An audio processing unit 125 may constitute a codec, and the codec includes a data codec for processing packet data, etc., and an audio codec for processing audio signals, such as speech, etc. The audio processing unit 125 converts a digital audio signal received in the modem 120 into an analog signal through the audio codec and plays it back, or converts an analog signal, which is generated by a microphone and is to be transmitted, into a digital audio signal through the audio codec, and then transmit it to the modem 120. The codec may be either separately arranged or included in the second control unit 110. A memory 130 may include a program memory, a data memory, etc. The program memory may store programs for controlling normal operations of the portable terminal and programs for controlling operations according to the present invention in which the digital data received from the camera is restored and the corresponding data information is displayed. Also, the data memory temporarily stores data generated during execution of the programs. The second control unit 110 controls the general operation of the portable terminal. The second control unit 110 may also include the modem 120 and the codec. The second control unit 110 also extracts the control signal information stored in the corresponding frame of the digital data which is received by photographing by a camera unit 140 according to an embodiment of the present invention, and calibrates the corresponding frame using the control signal information. The control signal information includes the intensity calibration signal, the tilt calibration signal and the synchronizing signal. The second control unit 110 controls the intensity calibration through the intensity calibration signal, in which when the pixel data values of the corresponding frame are different from that of the pixel data of the intensity calibration signal, the intensity of the corresponding frame is calibrated into predetermined values. Furthermore, the second control unit 110 controls the tilt calibration through the tilt calibration signal of the control signal information, in which when the size of the corresponding frame is out of the at least one reference value of the tilt calibration signal, the second control unit 110 extracts the degree of the tilt of the corresponding frame and calibrates the tilt of the corresponding frame. The second control unit 110 also extracts the number of the corresponding frame through the synchronizing signal of the control signal information. The second control unit 110 controls the restoration of the calibrated corresponding frame and the display of corresponding data information of the restored frame on the display unit 160. The second control unit 110 controls the intensity calibration of pixel data of the corresponding frame of the digital data photographed by the camera unit 140. The second control unit 110 controls the extraction of the degree of the tilt of the corresponding frame of the digital data photographed by the camera unit 140 and the calibration of the tilt of the corresponding frame through the tilt calibration signal. The second control unit 110 controls the extraction of the number of the corresponding frame of the digital data photographed by the camera unit 140 through the synchronizing signal. Moreover, the second control unit 110 controls the restoration of the corresponding frame according to an embodiment of the present invention, and controls the display of the corresponding data information of the corresponding frame, that is, at least one data channel information for the corresponding frame. The camera unit 140 includes a camera sensor for photographing the image data and converting a photographed optical signal into an electric signal and a signal processing unit for converting an analog image signal photographed by the camera sensor into digital data. Here, the camera sensor is assumed to be a Charge Coupled Device (CCD) sensor, and the signal processing unit may be implemented by a Digital Signal Processor (DSP). Furthermore, the camera sensor and the signal processing unit may be implemented by either a single unit or separated units. The camera unit 140 receives the data of digital signal in accordance with an embodiment of the present invention, and transfers the received data of digital signal to an image processing unit 150. The image processing unit 150 generates screen data for displaying the image signal output from the camera unit 140. The image processing unit 150 processes an image signal output from the camera unit 140 frame-by-frame, and outputs the frame image data with the feature and size appropriate to the second display unit 160. The image processing unit 150 also includes an image codec, and compresses the frame image data displayed on the second display unit 160 in a preset mode, or restores the compressed frame image data into original frame image data. Here, the image codec may be a JPEG codec, a MPEG4 codec, a Wavelet codec, etc. The image processing unit 150 is assumed to include an On-Screen Display (OSD) function, and then may output on-screen display data based on a screen size to be displayed under the control of the second control unit 110. In addition, the image processing unit 150 restores the corresponding frame of the digital data received by photographing by the camera unit 140 in accordance with the present invention into original corresponding data, and outputs the restored corresponding data information to the second display unit 160. The second display unit 160 displays the image signal output from the image processing unit 150 on the screen, and displays user data output from the second control unit 110. Here, a Liquid Crystal Display (LCD) may be applied to the second display unit 160; in this case, the second display unit 160 may include a LCD controller, a memory capable storing image data, a LCD display element, etc. In a case where the LCD is of a touch screen type, the LCD may be an input unit as well. The second display unit 160 also displays the corresponding data information which is input from the image processing unit 150 according to an embodiment of the present invention, namely, at least one piece of data channel information included in the corresponding frame. A key input unit 127 includes keys for input of numeral and character information, and function keys for setting various functions. Data transmitting/receiving operations of the aforementioned data transmission/reception apparatus is described below with reference to FIG. 4. In FIG. 4 together with FIGS. 1 to 3, an embodiment of the present invention will be described below. In FIG. 4, in step 301, the data service providing unit transfers the digital data, of which each frame includes at least one data channel, to the display device 200, and then in step 302, the first control unit 240 in the display device, detects it and causes the receiver to receive the corresponding frame of the digital data. The first control unit 240 creates the control signal information, which includes the intensity calibration signal, the tilt calibration signal and the synchronizing signal, from the frame information stored in the corresponding frame of the digital data in step 303. In step 304, the first control unit 240 causes the digital data to be stored in the image buffer 220 frame by frame, and makes the control signal information to be contained in the corresponding frame of the digital data. And, the first control unit 240 causes the first display unit 230 to display the corresponding frame of the digital data, which contains the control signal information and is stored in the image buffer 220, based on the display information stored in the frame information in step 305. While the display device 200 displays the corresponding frame of the digital data on the first display unit 230, the receiver 100 receives, in step 306 of a camera photographing mode, the corresponding frame of the digital data by the camera unit 140, and then the second control unit 110 in the portable terminal detects it in step 307 and performs steps 308 to 310, in which the calibrations of the corresponding frame of the digital data are carried out. The second control unit 110 extracts the control signal information contained the corresponding frame of the digital data, and calibrates the corresponding frame of the digital data through the control signal information including the intensity calibration signal, the tilt calibration signal and the synchronizing signal. In step 308, the second control unit 110 first performs the intensity calibration of the corresponding frame of the digital data. The second control unit 110 compares the pixel data values of the intensity calibration signal with the actual pixel data values stored at the predetermined positions at which the intensity calibration signal is stored in the step 308. When the actual pixel data values are different from the pixel data values of the intensity calibration signal, the second control unit 110 calibrates the pixel data of the corresponding frame into the predetermined values. After the intensity calibration, the second control unit 110 performs the tilt calibration of the corresponding frame of the digital data in step 309. In step 309, the second control unit 110 determines whether the size of the corresponding frame is out of at least one reference value of the tilt calibration signal, that is, at least one reference value configured according to the size of the corresponding frame. If the corresponding frame is out of the at least one reference value, the second control unit 110 detects it and determines that tilt has occurred in the photographed corresponding frame. The second control unit 110 then extracts the degree of the tilt of the corresponding frame through the at least one reference value and calibrates it. Furthermore, the second control unit 110 extracts the number of the corresponding frame of the digital data through the synchronizing signal in step 310. The second control unit 110 detects when the calibrations of step 308 to 310 are finished, and performs step 311, in which the second control unit 110 causes the image processing unit 150 to restore the corresponding frame to have original data. The second control unit 10 performs step 312, in which corresponding data information restored in the step 311 is displayed on the display unit 160. In step 312, at least one data channel, which is the corresponding data information, included in the corresponding frame may be displayed on the display unit 160. When a predetermined data channel is selected from the at least one data channel displayed on the display unit 160, information for the selected data may be displayed, and the selected channel may be displayed to be played-back. A data transfer rate on the basis of Video Graphics Array (VGA) grade (640*480) from the display device 200 corresponding to the transmitter in the present invention to the portable terminal 100 corresponding to the receiver can be up to “300 kbps (pixel speed)*256 (color-depth)*30 frames=2.3 Gbps”. In the case where data compression is with an H.264 codec (384 kbps, QVGA 30 frames), which is currently being used, broadcast contents with 256 Quarter Video Graphics Array (QVGA) grade can be received in a multi-user environment. However, in case of normal data transfer (e.g., web-service, e-mail, streaming, up-link channel separate configuration), data can be transferred at a rate of 2.3 Gbps. As described above, the present invention transmits and receives data by using the display device capable of receiving and displaying digital data and the portable terminal capable of receiving digital data by photographing digital data. The present invention, therefore, provides the added function of receiving data within a short-range so as to replace existing handheld broadcasting devices. In particular, the present invention also has the added advantage of allowing, for example, a large-sized screen or LCD TV generally found in public places to be used for data communication in a multi-user environment. While the invention has been shown and described with reference to certain exemplary embodiments such as the portable terminal, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention should in no way be limited to the exemplary embodiments, but should be defined by the appended claims along with the full scope of equivalents thereof.
|
H
|
H04
|
H04N
|
52
|
25
|
|||
11843429
|
US20080214107A1-20080904
|
Upstream Broad Beam Diversity
|
ACCEPTED
|
20080820
|
20080904
|
[]
|
H04B7185
|
["H04B7185"]
|
7929909
|
20070822
|
20110419
|
455
|
013100
|
60633.0
|
GESESSE
|
TILAHUN
|
[{"inventor_name_last": "Dankberg", "inventor_name_first": "Mark D.", "inventor_city": "Encinitas", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Pateros", "inventor_name_first": "Charles N.", "inventor_city": "Carlsbad", "inventor_state": "CA", "inventor_country": "US"}]
|
A satellite communication system is provided according to one embodiment of the invention. The satellite communication system includes a gateway with first and second antennas. The first antenna receives a signal from a first satellite that includes at least a first signal from a first user. The second antenna receives a second signal from a second satellite, that includes at least a second primary signal from a second user and a version of the first signal. The gateway may include circuitry to isolate the first signal from the second signal. The gateway may also include a combiner configured to combine the first signal from the first satellite and the first signal isolated from the second signal. Various other embodiments are disclosed that isolate a secondary signal received from a satellite and combine the secondary signal with the same signal received from other antennas at the gateway.
|
1. A satellite communication gateway comprising: a first antenna configured to receive a signal from a first satellite, wherein the signal received from the first satellite includes at least a first signal from a first user; a second antenna configured to receive a second signal from a second satellite, wherein the second signal includes at least a second primary signal from a second user and a second secondary signal; a demodulator-remodulator configured to isolate the second primary signal from the second signal; and an adder configured to subtract the second primary signal from the second signal; and a combiner configured to combine the first signal and the second secondary signal, wherein the second secondary signal includes a version of the first signal. 2. The satellite communication gateway of claim 1, further comprising: a third antenna configured to receive a signal from a third satellite, wherein the signal received from the third satellite includes at least a third primary signal from a third user and a third secondary signal; a demodulator-remodulator configured to isolate the third signal; and an adder configured to subtract the third primary signal from the third signal, wherein the combiner is configured to combine the first signal, the second secondary signal and the third secondary signal, wherein the third secondary signal includes a version of the first signal. 3. The satellite communication gateway of claim 1, wherein the combiner is a maximal ratio combiner. 4. The satellite communication gateway of claim 1, wherein the first user leases access to the first satellite. 5. The satellite communication gateway of claim 1, wherein the first user does not lease access to the second satellite. 6. The satellite communication gateway of claim 2, wherein the first user does not lease access to the third satellite. 7. A satellite communication method comprising: receiving a signal from a first satellite, wherein the signal from the first satellite includes at least a first signal from a first user; receiving a signal from a second satellite, wherein the signal from the second satellite includes at least a second primary signal from a second user and a second secondary signal; canceling the second primary signal from the second signal; and combining the second signal and the first signal, wherein the second secondary signal includes a version of the first signal. 8. The method according to claim 7, further comprising delaying either the first or the second signal prior to the combining. 9. The method according to claim 7, wherein the combining includes maximal ratio combining. 10. The method according to claim 7, wherein the canceling includes demodulating the second signal using noise canceling techniques. 11. The method according to claim 7, wherein the first user leases access to the first satellite. 12. The method according to claim 7, wherein the first user does not lease access to the second satellite. 13. The method according to claim 7, further comprising: receiving a signal from a third satellite, wherein the signal from the third satellite includes at least a third primary signal from a third user and a third secondary signal; canceling the third primary signal from the third signal; and combining the third signal, the second signal, and the first signal, wherein the third secondary signal includes a version of the first signal. 14. The method according to claim 13, wherein the first user does not lease access to the third satellite. 15. A satellite communication method comprising: receiving a first signal from a first satellite, wherein the first signal includes at least a first primary signal from a first user and a second signal from a second user; receiving a third signal from a second satellite, wherein the third signal includes at least a third primary signal from a third user and a version of the second signal; isolating the second signal from the first signal; isolating the second signal from the third signal; and combining the second signal isolated from the first signal and the second signal isolated from the third signal. 16. The satellite communication method according to claim 15, wherein the second user does not lease access to the first satellite and the second user does not lease access to the third satellite.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>This disclosure relates in general to satellite communication systems and, but not by way of limitation, to satellite communication systems using multiple satellites. Satellites are power limited. That is, satellites have a limited power resources that can be used for communications, propulsion, processing, steering etc. Increasing the power available to these resources can be very expensive. Thus, satellite systems are often designed with tight power budgets. Therefore, increasing power to a communication link can be very expensive. On the other hand, the performance of a communication link can be proportional to the power associated with the communication link. Thus, a balance is often struck between performance gains and cost when considering designing a satellite communication system. Gateway antennas are often larger than subscriber terminal antennas. Accordingly, the return link between the satellite and gateway can be lower powered than the link between the satellite and a subscriber terminal. Moreover, performance gains may be important between the gateway and the satellite because of these often lower powered signals. There is a general need in the art to provide increased satellite signal strength without greatly increasing the costs of the overall satellite system.
|
<SOH> BRIEF SUMMARY OF THE INVENTION <EOH>A satellite communication gateway is provided according to one embodiment of the invention. The gateway may include a first and second antenna. The first antenna may be configured to receive a signal from a first satellite that includes at least a first signal from a first user. The second antenna may be configured to receive a second signal from a second satellite that includes at least a second primary signal from a second user and a second secondary signal. The second secondary signal may include a version of the first signal from the first user. The gateway may also include a demodulator-remodulator configured to isolate the second primary signal from the second signal and an adder configured to subtract the second primary signal from the second signal leaving the second secondary signal. The gateway may also include a combiner configured to combine the first signal received at the first antenna and the second secondary signal received at the second antenna. According to one embodiment of the invention, the first user and/or the gateway does not lease access to the second satellite. The satellite communication gateway may also include a third antenna configured to receive a signal from a third satellite. This third signal include at least a third primary signal from a third user and a third secondary signal. The third secondary signal may include a version of the first signal from the first user. The gateway may also include a demodulator-remodulator configured to isolate the third primary signal from the third signal and an adder configured to subtract the third primary signal from the third signal leaving the third secondary signal. The gateway may also include a combiner configured to combine the first signal received at the first antenna and the third secondary signal received at the third antenna. According to one embodiment of the invention, the first user and/or the gateway does not lease access to the third satellite. In one embodiment, the gateway may include one or more combiners and/or remodulators/demodulators. In another embodiment the combiner may be a maximal ratio combiner. A satellite communication method is also provided according to one embodiment of the invention. The method includes receiving a first signal from a first satellite The signal from the first satellite may include at least a first signal from a first user. The method also includes receiving a second signal from a second satellite. The signal from the second satellite may include at least a second primary signal from a second user and a second secondary signal. The second secondary signal may include a version of the first signal. The second primary signal may be canceled from the second signal. The resulting second signal may then be combined with the first signal. The method may also include delaying either the first or the second signal prior to the combining. The combining may include maximal ratio combining. The canceling may include demodulating the second signal using noise canceling techniques and/or forward error correction (FEC) decoding and/or encoding. The first user may leases access to the first satellite but does not lease access to the second satellite. The satellite communication method may also include receiving a third signal from a third satellite according to another embodiment of the invention. The third signal from the third satellite includes at least a third primary signal from a third user and a third secondary signal. The third secondary signal may include a version of the first signal. The third primary signal may be canceled from the third signal using interference canceling techniques. The resulting third signal may then be combined with the first signal. The first user may not lease access to the third satellite. Another satellite communication method is provided according to one embodiment of the invention. The method includes receiving a first and third signal from first and third satellites. The first signal includes at least a first primary signal from a first user and a second signal from a second user. The third signal includes at least a third primary signal from a third user and the second signal. These signals may be received at a gateway. The method also includes isolating the second signal from a version of the first signal and isolating the second signal from the third signal. The second signal isolated from the first signal and the second signal isolated from the third signal may then be combined. According to another embodiment of the invention the second user and/or the gateway does not lease access to the first or third satellites. Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating various embodiments, are intended for purposes of illustration only and are not intended to necessarily limit the scope of the disclosure.
|
CROSS-REFERENCES TO RELATED APPLICATIONS This application is a non-provisional, and claims the benefit, of commonly assigned U.S. Provisional Application No. 60/823,126, filed Aug. 22, 2006, entitled “Feeder Link Polarization Diversity,” the entirety of which is herein incorporated by reference for all purposes. This application is a non-provisional, and claims the benefit, of commonly assigned U.S. Provisional Application No. 60/823,127, filed Aug. 22, 2006, entitled “Downstream Broad Beam Diversity,” the entirety of which is herein incorporated by reference for all purposes. This application is a non-provisional, and claims the benefit, of commonly assigned U.S. Provisional Application No. 60/823,128, filed Aug. 22, 2006, entitled “Downstream Broad Beam Diversity With Interference Cancellation,” the entirety of which is herein incorporated by reference for all purposes. This application is a non-provisional, and claims the benefit, of commonly assigned U.S. Provisional Application No. 60/823,131, filed Aug. 22, 2006, entitled “Upstream Broad Beam Diversity,” the entirety of which is herein incorporated by reference for all purposes. This application is related to commonly assigned U.S. patent application Ser. No. ______, filed Aug. 22, 2007, entitled “Cooperative Orthogonal Multi-Satellite Communication System,” the entirety of which is herein incorporated by reference for all purposes. This application is related to commonly assigned U.S. patent application Ser. No. ______, filed Aug. 22, 2007, entitled “Downstream Broad Beam Diversity,” the entirety of which is herein incorporated by reference for all purposes. This application is related to commonly assigned U.S. patent application Ser. No. ______, filed Aug. 22, 2007, entitled “Downstream Broad Beam Diversity With Interference Cancellation,” the entirety of which is herein incorporated by reference for all purposes. BACKGROUND OF THE INVENTION This disclosure relates in general to satellite communication systems and, but not by way of limitation, to satellite communication systems using multiple satellites. Satellites are power limited. That is, satellites have a limited power resources that can be used for communications, propulsion, processing, steering etc. Increasing the power available to these resources can be very expensive. Thus, satellite systems are often designed with tight power budgets. Therefore, increasing power to a communication link can be very expensive. On the other hand, the performance of a communication link can be proportional to the power associated with the communication link. Thus, a balance is often struck between performance gains and cost when considering designing a satellite communication system. Gateway antennas are often larger than subscriber terminal antennas. Accordingly, the return link between the satellite and gateway can be lower powered than the link between the satellite and a subscriber terminal. Moreover, performance gains may be important between the gateway and the satellite because of these often lower powered signals. There is a general need in the art to provide increased satellite signal strength without greatly increasing the costs of the overall satellite system. BRIEF SUMMARY OF THE INVENTION A satellite communication gateway is provided according to one embodiment of the invention. The gateway may include a first and second antenna. The first antenna may be configured to receive a signal from a first satellite that includes at least a first signal from a first user. The second antenna may be configured to receive a second signal from a second satellite that includes at least a second primary signal from a second user and a second secondary signal. The second secondary signal may include a version of the first signal from the first user. The gateway may also include a demodulator-remodulator configured to isolate the second primary signal from the second signal and an adder configured to subtract the second primary signal from the second signal leaving the second secondary signal. The gateway may also include a combiner configured to combine the first signal received at the first antenna and the second secondary signal received at the second antenna. According to one embodiment of the invention, the first user and/or the gateway does not lease access to the second satellite. The satellite communication gateway may also include a third antenna configured to receive a signal from a third satellite. This third signal include at least a third primary signal from a third user and a third secondary signal. The third secondary signal may include a version of the first signal from the first user. The gateway may also include a demodulator-remodulator configured to isolate the third primary signal from the third signal and an adder configured to subtract the third primary signal from the third signal leaving the third secondary signal. The gateway may also include a combiner configured to combine the first signal received at the first antenna and the third secondary signal received at the third antenna. According to one embodiment of the invention, the first user and/or the gateway does not lease access to the third satellite. In one embodiment, the gateway may include one or more combiners and/or remodulators/demodulators. In another embodiment the combiner may be a maximal ratio combiner. A satellite communication method is also provided according to one embodiment of the invention. The method includes receiving a first signal from a first satellite The signal from the first satellite may include at least a first signal from a first user. The method also includes receiving a second signal from a second satellite. The signal from the second satellite may include at least a second primary signal from a second user and a second secondary signal. The second secondary signal may include a version of the first signal. The second primary signal may be canceled from the second signal. The resulting second signal may then be combined with the first signal. The method may also include delaying either the first or the second signal prior to the combining. The combining may include maximal ratio combining. The canceling may include demodulating the second signal using noise canceling techniques and/or forward error correction (FEC) decoding and/or encoding. The first user may leases access to the first satellite but does not lease access to the second satellite. The satellite communication method may also include receiving a third signal from a third satellite according to another embodiment of the invention. The third signal from the third satellite includes at least a third primary signal from a third user and a third secondary signal. The third secondary signal may include a version of the first signal. The third primary signal may be canceled from the third signal using interference canceling techniques. The resulting third signal may then be combined with the first signal. The first user may not lease access to the third satellite. Another satellite communication method is provided according to one embodiment of the invention. The method includes receiving a first and third signal from first and third satellites. The first signal includes at least a first primary signal from a first user and a second signal from a second user. The third signal includes at least a third primary signal from a third user and the second signal. These signals may be received at a gateway. The method also includes isolating the second signal from a version of the first signal and isolating the second signal from the third signal. The second signal isolated from the first signal and the second signal isolated from the third signal may then be combined. According to another embodiment of the invention the second user and/or the gateway does not lease access to the first or third satellites. Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating various embodiments, are intended for purposes of illustration only and are not intended to necessarily limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a common satellite communication system showing multiple subscriber terminals, each of which communicates with a gateway through an independent satellite. FIG. 2 shows a satellite communication system according to one embodiment of the invention. FIG. 3 shows a flowchart showing a method for combining signals received from the subscriber terminal according to one embodiment of the invention. FIG. 4 shows a satellite communication system according to another embodiment of the invention. FIG. 5 shows another satellite communication system according to another embodiment of the invention. FIG. 6 shows a flow chart for isolating and adding the signals received from secondary satellites according to another embodiment of the invention. In the appended figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label. DETAILED DESCRIPTION OF THE INVENTION The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims. Embodiments of the present disclosure provide for a satellite communication system that utilizes unleased satellites for communication between, for example, subscriber terminals and a gateway. FIG. 1 depicts a common satellite communication system showing multiple subscriber terminals 120, each of which communicate with a gateway 130 through a satellite 110. As shown, a first subscriber terminal 120-A communicates with a first gateway 130-A through a first link established through a first satellite 110-A. Also shown is a second subscriber terminal 120-B that communicates with a second gateway 130-B through second a link established through a second satellite 110-B. A third subscriber terminal 120-C communicates with a third gateway 130-C through a third link established through a third satellite 110-C. Thus, each of the three subscriber terminals 120 independently communicates with the gateway 130 through a link established by one of the three satellites 110. In practical systems, there are often multiple terminals communicating with each gateway, while only one terminal per gateway is shown in the figure for clarity. Each of the antennas 115 at the three subscriber terminals 120 and/or each of the antennas 131 of the gateways 130 are pointed toward a primary satellite. For instance the antenna 115-A at the first subscriber terminal 120-A is pointed at the first satellite 110-A, and so on. Moreover, the operators of the gateways 130 and/or the subscriber terminals 120 may lease or purchase communication access through the corresponding satellite 110. This primary access may provide the operators the necessary coding and/or encryption schemes in order to communicate through the satellite link. Moreover, the three satellites may be within the same orbital slot, in adjacent orbital slots, or in neighboring orbital slots. Signals received at the gateway antenna 131-B from the first satellite 110-A and the third satellite 110-C may be considered interference by the second gateway antenna 131-B. Similarly, signals received at the first gateway antenna 131-A from the second satellite 110-B and the third satellite 110-C may be considered interference by the first gateway antenna 131-A. Signals received at the third gateway antenna 131-C from the second satellite 110-B and the first satellite 110-A may be considered interference by the third gateway antenna 131-C. Despite each subscriber terminal being pointed at a primary satellite, off axis signals may be transmitted to a neighboring, secondary satellite. For example, from the point of view of the first subscriber terminal 120-A the first satellite 110-A is the primary satellite. The first subscriber terminal 120-A may be pointed toward the first satellite 110-A. Moreover, the first subscriber terminal 110-A may lease or purchase access to communication with the first satellite 110-A or be provided access to the first satellite 110-A. The second satellite 110-B and the third satellite 120-C may be considered secondary satellites to the first subscriber terminal 110-A. The first gateway antenna 131-A may be pointed toward the first satellite 110-A and may consider the first satellite 110-A the primary satellite and the second and third satellites 110-B, 110-C secondary satellites. One embodiment of the invention provides for a gateway that includes at least a first and second antenna. The first antenna receives a first signal from a first satellite. The first signal may be a primary signal received from a first user. The second antenna may receive a second signal from a second satellite. This second signal may include a primary signal from a second user and a version of the first signal from the first user. The gateway may remove the second primary signal from the second signal leaving the first signal using any of various interference canceling techniques known in the art. The first signal received from the first satellite and the version of the first signal received from the second satellite may then be combined. This combination may improve the performance of the signal received from the first user. The gateway and/or the first user may not be provided access to the second satellite. Another embodiment of the invention may include a gateway with a third antenna. The third antenna may receive a third signal from a third satellite. This third signal may include a primary signal from a third user and a version of the first signal. The gateway may remove the third primary signal from the third signal leaving the first signal using any of various interference canceling techniques known in the art. The first signal received from each of the first satellite, the second satellite and the third satellite may be combined. Another embodiment of the invention provides for a gateway that includes at least a first and second antenna. The first antenna receives a first signal from a first satellite and the second antenna receives a second signal from a second satellite. The first signal may include a first signal from a first user and a third signal from a third user. The second signal may include a second signal from a second user and the third signal. The third signal from the third user may be isolated from both the first and second signals at the gateway using any of various interference canceling techniques known in the art and combined providing a combined third signal. The gateway and/or subscriber terminals may not have primary access to the first and/or second satellites. FIG. 2 shows a satellite communication system according to one embodiment of the invention. A subscriber terminal 120 includes an antenna 115. In this embodiment, the subscriber terminal is a mobile subscriber terminal mounted on a truck. In other embodiments the subscriber terminal may stationary, spaceborne, seaborne, or airborne. While not shown in FIG. 2, more than one subscriber terminal may be used. The subscriber terminal 120 communicates with a gateway 130 using a gateway antenna 131-B through a primary satellite 110-B over return service link 126-B and return feeder link 127-B. The gateway 130 communicates with the subscriber terminal over forward feeder links 128 and forward service links 129. The gateway 130 may be connected to a network (not shown). The network may be any type of network and can include, for example, the Internet, an IP network, an intranet, a wide-area network (“WAN”), a local-area network (“LAN”), a virtual private network, the Public Switched Telephone Network (“PSTN”), a cluster of computers, and/or any other type of network supporting data communication between devices described herein, in different embodiments. A network may include both wired and wireless connections, including optical links. Many other examples are possible and apparent to those skilled in the art in light of this disclosure. As illustrated in a number of embodiments, the network may connect the gateway 130 with other gateways (not pictured), which are also in communication with satellites 110. The subscriber terminal antenna 115 may have a small aperture due to a number of reasons such as portability, ease of deployment, etc. Thus, the antenna may also have a relatively large beam width. For example, the beam width may be 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11° or 12° and fractions thereof. In other embodiments, the beam width may be larger than 12°. For purposes of presenting this embodiment, the second satellite 110-B is the primary satellite, the other two satellites are secondary satellites 110-A, 110-C. The satellites 110 may be positioned within adjacent orbital slots. Accordingly, the satellites may be separated by at least 20. In another embodiment, the satellites 110 may be in non-adjacent orbital slots. In yet another embodiment two or more of the satellites 110 may also be within the same orbital slot. More than one secondary satellites may also be used. For example, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 secondary satellites may be used and may be located in the same, adjacent and/or nonadjacent orbital slots. The subscriber terminal antenna 115 may be pointed toward the primary satellite 110-B. Similarly, the middle gateway antenna 131-B may also be pointed toward the primary satellite 110-B. The operators of the gateway 130 may lease access to the primary satellite 110-B. This primary access may provide a satellite transmission relay between the gateway 130 and the subscriber terminal 120. The gateway 130 may not lease access to the secondary satellites 110-A, 110-C shown in the figure. The gateway may, however, know the operating parameters of the secondary satellites 110-A, 110-C. For example, the gateway or gateway operators may know the access and code structure used in communication using satellites 110-A, 110-C. Moreover, the gateway may know the communication parameters used to modulate and/or encode the signals sent over the secondary satellites 110-A, 110-C. In one embodiment of the invention, the gateway or gateway operators may not know how to decrypt the data encoded and transmitted through the secondary satellites 110-A, 110-C. In one embodiment, a commercial encoder/decoder may be used to decode signals from the secondary satellites 110-A, 110-C. The subscriber terminal 120 broadcasts a return link signal 126 to all three satellites 110. While the subscriber terminal antenna 115 is pointed toward satellite 110-B and primarily transmits a signal 126-B toward the primary satellite 110-B, off axis signals from the antenna 115 may be broadcast to the secondary satellites 110-A, 110-C. Secondary satellites 110-A, 110-C receive and transmit signals unrelated to the signals 126-A, 126-B received from the subscriber terminal 120. For instance, various other users have leased or purchased access to secondary satellites 110-A, 110-C. The operator(s) of the subscriber terminal 120 and the operators of the gateway 130 have not leased access to the secondary satellites 110-A, 110-C for the purposes of communication between the gateway 130 and the subscriber terminal 120. Despite not leasing or purchasing access to the secondary satellites 110-A, 110-C, off-axis signals 126-A, 126-B from subscriber terminal 120 are received by the secondary satellites 110-A, 110-C and retransmitted to the gateway 130 through antennas 131-A, 131-C. Primary signals are also received at the secondary satellites 110-A, 110-C and rebroadcast. These signals are received from an intended subscriber terminal (not shown) and may interfere with the secondary signals from the subscriber terminal. The signals from the intended subscriber terminals and the subscriber terminal 120 will be transmitted to the gateway as a composite signal 127-A, 127-C. FIG. 3 shows a flowchart showing a method for combining signals A, B, and C received from the subscriber terminal 120 through the satellites 110 according to one embodiment of the invention. Signals are received from the three satellites at blocks 305. The signals received from the secondary satellites 110-A, 110-C are each independently received and processed to remove the primary signal using interference removal techniques. The signals are individually demodulated at blocks 310. The demodulated signals may be FEC decoded at blocks 315 using any type of commonly used FEC decoder such as, but not limited to, convolutional decoder, block decoder or turbo (iterative) decoder. The symbols may then be FEC encoded at blocks 320 and remodulated where it is reshaped into a replica of the primary component of the received waveform at blocks 325. The remod-demod and decode-encode steps isolate the primary A and C signals from the signals received from the secondary satellites. Those skilled in the art will recognize that there are various other ways to isolate these signals without deviating from spirit of the present invention. For example, various interference removal techniques may be employed. Once isolated, the timing, phase and/or gain may be corrected at block 330. Isolated signals A and C may then be subtracted from the signals received from the secondary satellites at blocks 335. Specifically, isolated signal A is subtracted from the signal received from the first secondary satellite 110-A. Isolated signal C is subtracted from the signal received from the second secondary satellite 110-C. Moreover, a delay may be adjusted to the signals in order to counteract any path length variations. Once the isolated primary signal has been subtracted the secondary signals remain and may be added with the signal received from the primary satellite 110-B at block 340. Signal B may then be demodulated and decoded at block 350. In another embodiment of the invention delays appropriate to the various versions of the signal of interest may be introduced in order to align the signals prior to the adder. FIG. 4 shows a satellite communication system with multiple subscriber terminals according to one embodiment of the invention. According to this embodiment of the invention multiple subscriber terminals 120 communicate with gateway 130 through satellites 110. Each subscriber terminal 120 is similar to the subscriber terminal describe in conjunction with FIG. 2. That is, each subscriber terminal 120 broadcasts a return link signals 126 to all three satellites 110. While the subscriber terminal antennas 115 are pointed toward satellite 110-B and primarily transmit a signal 126-B toward the primary satellite 110-B, off axis signals from the antenna 115 may be broadcast to the secondary satellites 110-A, 110-C. All three signals are then retransmitted from the satellites 110 to the gateway 130. The various signals may be encoded using OFDM, TDMA, SCDMA, or other coding techniques and/or spread spectrum techniques. FIG. 5 shows another satellite communication system according to another embodiment of the invention. According to this embodiment of the invention, subscriber terminal 120 transmits signals 126 to the gateway 130 through two secondary satellites 110-A, 110-B. According to this embodiment of the invention, the subscriber terminal does not transmit signals to a primary satellite. Both secondary satellites do not provide primary access to the subscriber terminal and/or to the gateway. FIG. 6 shows a flow chart for isolating and adding the signals received from the secondary satellites 110-A, 110-C shown in FIG. 5 according to another embodiment of the invention. The signals may be received and processed, for example, at a gateway. Primary signal A is received at the first secondary satellite 110-A and primary signal C is received at the second secondary satellite 110-C. Both secondary satellites also receive signal B as a secondary signal. The goal of the flow chart is to isolate the secondary signals by subtracting out the primary signals and then adding the secondary signals. Signals A and C are received from their respective satellites at blocks 605. The primary signals, signal A and signal C, are then demodulated at blocks 610 and decoded at blocks 615. The primary signals are then recoded at blocks 620 and remodulated at blocks 625. The primary signals are then subtracted from the received signal at blocks 635. Once subtracted, the secondary signals, signal B, is left. According to this embodiment, the two channels produce two signals that may then be added together at block 640 and demodulated at block 645. A delay in one or both channels may be introduced as well. The signals may be added using maximal ratio combining or any other soft combining. Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. Implementation of the techniques, blocks, steps and means described above may be done in various ways. For example, these techniques, blocks, steps and means may be implemented in hardware, software, or a combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described above and/or a combination thereof. Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function. Furthermore, embodiments may be implemented by hardware, software, scripting languages, firmware, middleware, microcode, hardware description languages and/or any combination thereof. When implemented in software, firmware, middleware, scripting language and/or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium, such as a storage medium. A code segment or machine-executable instruction may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a script, a class, or any combination of instructions, data structures and/or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters and/or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc. For a firmware and/or software implementation, the methodologies may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software codes may be stored in a memory. Memory may be implemented within the processor or external to the processor. As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other storage medium and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored. Moreover, as disclosed herein, the term “storage medium” may represent one or more devices for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage mediums, optical storage mediums, flash memory devices and/or other machine readable mediums for storing information. The term “machine-readable medium” includes, but is not limited to portable or fixed storage devices, optical storage devices, wireless channels and/or various other mediums capable of storing, containing or carrying instruction(s) and/or data. While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the disclosure.
|
H
|
H04
|
H04B
|
71
|
85
|
|||
11974021
|
US20080123148A1-20080529
|
Reduction of uneven print density
|
ACCEPTED
|
20080514
|
20080529
|
[]
|
G06K1500
|
["G06K1500"]
|
8208176
|
20071010
|
20120626
|
358
|
003060
|
97226.0
|
NGUYEN
|
ALLEN
|
[{"inventor_name_last": "Takahashi", "inventor_name_first": "Toru", "inventor_city": "Matsumoto-shi", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Kakutani", "inventor_name_first": "Toshiaki", "inventor_city": "Shiojiri-shi", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Yamazaki", "inventor_name_first": "Satoshi", "inventor_city": "Shiojiri-shi", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Tanase", "inventor_name_first": "Kazuyoshi", "inventor_city": "Shiojiri-shi", "inventor_state": "", "inventor_country": "JP"}]
|
The invention provides a printing method of printing on a printing medium. The method includes: generating dot data that represents state of dot formation at each print pixel of a print image to be formed on the printing medium by performing a halftone process on image data that represents an input tone value of each pixel making up an original image; and generating the print image by forming dots on each of the print pixels according to the dot data. The halftone process determines the state of dot formation by using a dither matrix that stores a plurality of threshold values, the plurality of threshold values being used for determining state of dot formation at each of print pixels of the print image to be formed on the printing medium according to an input tone value. The dither matrix is a matrix that stores each of the plurality of threshold values in each element such that a mutual difference in dot density formed at each predetermined print pixel group according to each input tone value falls within a predetermined range. The predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements.
|
1. A printing method of printing on a printing medium, comprising: generating dot data that represents state of dot formation at each print pixel of a print image to be formed on the printing medium by performing a halftone process on image data that represents an input tone value of each pixel making up an original image; and generating the print image by forming dots on each of the print pixels according to the dot data, wherein the halftone process determines the state of dot formation by using a dither matrix that stores a plurality of threshold values, the plurality of threshold values being used for determining state of dot formation at each of print pixels of the print image to be formed on the printing medium according to an input tone value; the dither matrix is a matrix that stores each of the plurality of threshold values in each element such that a mutual difference in dot density formed at each predetermined print pixel group according to each input tone value falls within a predetermined range; and the predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements. 2. The printing method according to claim 1, wherein the dither matrix is generated by a predetermined dither matrix generation method, wherein the predetermined dither matrix generation method includes determining a storage element that determines a storage element for a target threshold value out of a plurality of candidate storage elements based on a matrix evaluation value, the matrix evaluation value representing correlation with a predetermined target state and each of a plurality of assumed states of dot formation, each of the plurality of assumed states of dot formation being configured such that the target threshold value is stored in each of a plurality of candidate storage elements that are candidate elements for storing the target threshold value, wherein the determining includes determining the storage element such that a mutual difference in dot density formed among the plurality of predetermined print pixel groups according to each input tone value falls within a predetermined range. 3. The printing method according to claim 2, wherein the predetermined dither matrix generation method further includes: selecting the target threshold value for which an element for storage is undetermined and has a greatest tendency to dot formation among the plurality of threshold values; and repeating the selecting the target threshold value and the determining the storage element with respect to at least a part of the plurality of threshold values. 4. The printing method according to claim 2, wherein the determining a storage element includes determining a number of elements belonging to each of the a plurality of element groups according to a size of the print pixel to reduce a change of size of the predetermined print pixel group along with a change of print resolution. 5. The printing method according to claim 2, wherein the matrix evaluation value includes a divided matrix evaluation value representing a correlation between the predetermined target state and the state of dot formation assumed with respect to the predetermined print pixel group. 6. The printing method according to claim 2, wherein the predetermined print pixel group has such a small size that allows for arrangement at a pitch equal to or greater than 5 cycles per millimeter. 7. The printing method according to claim 2, wherein the generating the print image includes forming dots on the printing medium while alternately performing main scan of a print head and sub scan of paper feed, and the predetermined print pixel group is a cluster of pixels neighboring in direction of the main scan. 8. The printing method according to claim 2, wherein the generating the print image includes forming dots on the printing medium while performing sub scan of paper feed, and the predetermined print pixel group is a cluster of pixels neighboring in direction of the sub scan. 9. The printing method according to claim 8, wherein the generating dot data includes generating the dot data by arranging the dither matrix with shifts in a direction perpendicular to the direction of the sub scan. 10. The printing method according to claim 2, wherein the generating the print image includes forming a print image by mutually combining dot groups in a common print region, each of the dot groups being formed in each of a plurality of pixel groups assumed to have a mutually physical difference in a process of dot formation, and the determining a storage element includes storing each of the plurality of threshold values into each element such that a degradation of image quality due to the physical difference is reduced. 11. The printing method according to claim 2, wherein the matrix evaluation value is a graininess index calculated by a computing process including a Fourier transform process, and the graininess index is calculated based on a VTF function that is determined based on visual spatial frequency characteristic and a constant that is calculated in advance by the Fourier transform process. 12. The printing method according to claim 2, wherein the matrix evaluation value is a RMS granularity that is calculated by a computing process including a low pass filtering process. 13. A printing apparatus that performs printing on a printing medium, comprising: a dot data generator that generates dot data that represents state of dot formation at each print pixel of a print image to be formed on the printing medium by performing a halftone process on image data that represents an input tone value of each pixel making up an original image; and a print image generator that generates the print image by forming dots on each of the print pixels according to the dot data, wherein the halftone process determines the state of dot formation by using a dither matrix that stores a plurality of threshold values, the plurality of threshold values being used for determining state of dot formation at each of print pixels of the print image to be formed on the printing medium according to an input tone value; the dither matrix is a matrix that stores each of the plurality of threshold values in each element such that a mutual difference in dot density formed at each predetermined print pixel group according to each input tone value falls within a predetermined range; and the predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements. 14. An apparatus for generating a dither matrix that stores each of a plurality of threshold values in each element, the plurality of threshold values being used for determining state of dot formation at each of print pixels of a print image to be formed on a printing medium according to an input tone value, the apparatus comprising: a storage element determining unit that determines a storage element for a target threshold value out of a plurality of candidate storage elements based on a matrix evaluation value, the matrix evaluation value representing correlation with a predetermined target state and each of a plurality of assumed states of dot formation, each of the plurality of assumed states of dot formation being configured such that the target threshold value is stored in each of a plurality of candidate storage elements that are candidate elements for storing the target threshold value, wherein the storage element determining unit determines the storage element such that a mutual difference in dot density formed among the plurality of predetermined print pixel groups according to each input tone value falls within a predetermined range; and the predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements. 15. A density calibration method of generating correction data for calibrating image density printed on a printing medium, the method comprising: generating dot data that represents state of dot formation, by using a dither matrix that stores a plurality of threshold values, the plurality of threshold values being used for determining state of dot formation at each of print pixels of a print image to be formed on a printing medium, according to calibration-use pattern data that includes uniform density image data generated by a uniform input tone value; forming dots on the printing medium according to the generated dot data; measuring density of the printed uniform density image with respect to each predetermined print pixel group; and generating correction data with respect to each predetermined region according to the measured density, the correction data including a correction value for reducing dispersion of density in the uniform density image, wherein the program includes a program for causing the computer to determine the storage element such that a mutual difference in dot density formed among the plurality of predetermined print pixel groups according to each input tone value falls within a predetermined range; and the predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements. 16. The density calibration method according to claim 15, wherein the forming dots includes forming dots on the printing medium while alternately performing main scan of a print head and sub scan of paper feed, and the predetermined print pixel group is a cluster of pixels neighboring in direction of the main scan. 17. The density calibration method according to claim 15, wherein the forming dots includes forming dots on the printing medium while performing sub scan of paper feed, and the predetermined print pixel group is a cluster of pixels neighboring in direction of the sub scan.
|
<SOH> BACKGROUND <EOH>1. Technical Field The present invention relates to technology for printing images by forming dots on a printing medium. 2. Related Art Printing devices that perform printing by using print heads while performing scans in main scanning direction and sub scanning direction include inkjet printers such as serial scan type printers, drum scan type printers, and the like. The inkjet printers form characters and images on printing media by ejecting inks from a plurality of nozzles of print heads. One of dot recording modes employed by the inkjet printers is a mode referred to as “interlace mode”. FIG. 27 is an illustration depicting how sub scan feed is performed in an interlace recording mode. A print head 1000 has four nozzles arranged in sub scanning direction. Numbers 0 - 3 indicated in circles are nozzle numbers. The nozzles are arranged at a pitch k of three dots in the sub scanning direction. Here, a unit of [dot] means a dot pitch [inch] in the sub scanning direction equivalent to a print resolution. Positions of the print head 1000 indicated as pass 1 , pass 2 , and so on in FIG. 27 represent positions in the sub scanning direction at the time of each main scan. Here, the “pass” means one main scan. After each main scan, a sub scan feed of a fixed feed amount L of four dots is executed. However, positions of dots formed by each nozzle may sometimes be misaligned in some degree in the sub scanning direction due to manufacturing error of nozzle. A dot pattern Dtp 1 of FIG. 27 is obtained under assumption that no such manufacturing error exists and all dot positions are normal. On the other hand, in case where dots formed by e.g. a first nozzle are misaligned upwards, there may be a space between a main scan line that has dots formed by the first nozzle and a main scan line that has dots formed by a zero nozzle, as shown in a dot pattern Dtp 2 of FIG. 27 . Such space may be observed by the naked eye as a portion of degraded image quality appearing as a streak, and is referred to as “banding”. The banding may be attributed not only to the manufacturing error of nozzle but also to several factors including error in sub scan feed, warpage of printing paper, and the like. In order to suppress such banding, a technique that performs correction by biasing density of each raster line is proposed (Patent Document 1). Specifically, in the example of the dot pattern Dtp 2 of FIG. 27 , the technique makes degradation of image quality appearing as a streak less noticeable by correcting and increasing densities of raster lines 6 , 7 as well as by correcting and reducing densities of raster lines 4 , 5 . In JP-A-2005-219286, a technique that performs a smoothing process of correction value based on densities of a plurality of neighboring raster lines is further proposed. Conventional techniques are under assumption that density of each raster line is reproduced accurately as long as no error exists in landing position of ink droplet, amount of ink, and the like. However, no consideration has been given to accuracy of density of each raster line in such case of no error. Furthermore, such problem has occurred not only as the problem of banding that is now becoming obvious, but also as a wider range of problem including irregularity of density, fidelity of color reproduction, and the like. In addition, such problem has been occurring not only in inkjet printers but also in laser printers.
|
<SOH> SUMMARY <EOH>An advantage of some aspect of the invention is to provide a technique for reducing uneven print density in a halftone process. According to an aspect of the invention, there is provided a printing method of printing on a printing medium. The method includes: generating dot data that represents state of dot formation at each print pixel of a print image to be formed on the printing medium by performing a halftone process on image data that represents an input tone value of each pixel making up an original image; and generating the print image by forming dots on each of the print pixels according to the dot data. The halftone process determines the state of dot formation by using a dither matrix that stores a plurality of threshold values, the plurality of threshold values being used for determining state of dot formation at each of print pixels of the print image to be formed on the printing medium according to an input tone value. The dither matrix is a matrix that stores each of the plurality of threshold values in each element such that a mutual difference in dot density formed at each predetermined print pixel group according to each input tone value falls within a predetermined range. The predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements. According to a printing device of the present invention, since dots can be formed such that difference in dot density formed at each predetermined print pixel group according to each input tone value falls within a predetermined range, a halftone process can be realized in such a way that reduces partial or local irregularity of density in a print image. Such reduction of density irregularity not only allows for improvement of fidelity of tone representation in a print image in monochromic printing and color printing, but also allows for reduction of deviation in hue by virtue of fidelity of density of each ink color. Here, the “dot density” means a product of a dot recording rate and a dot area, where the dot recording rate is a value obtained by dividing a number of dots formed by a number of pixels. Note that in case where plural sizes of dots are formed, the dot density is calculated by adding each product of a dot recording rate and a dot area with respect to each dot size. Note that in techniques disclosed in JP-A-2005-236768 and JP-A-2005-269527 that employ intermediate data (number data) for specifying state of dot formation, the use of dither matrix in the present invention has a broader concept that also includes the use of conversion table (or correspondence relationship table) generated using a dither matrix. Such conversion table is not only generated directly from a dither matrix generated by a generation method of the present invention, but may sometimes be adjusted or modified as well, and such cases also fall under the category of dither matrix generated by the generation method of the present invention. The invention also provides a density calibration method of generating correction data for calibrating image density printed on a printing medium. The method includes: generating dot data that represents state of dot formation, by using a dither matrix that stores a plurality of threshold values, the plurality of threshold values being used for determining state of dot formation at each of print pixels of a print image to be formed on a printing medium, according to calibration-use pattern data that includes uniform density image data generated by a uniform input tone value; forming dots on the printing medium according to the generated dot data; measuring density of the printed uniform density image with respect to each predetermined print pixel group; and generating correction data with respect to each predetermined region according to the measured density, the correction data including a correction value for reducing dispersion of density in the uniform density image. The program includes a program for causing the computer to determine the storage element such that a mutual difference in dot density formed among the plurality of predetermined print pixel groups according to each input tone value falls within a predetermined range. The predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements. In a density calibration method that employs a conventional dither matrix, there has been a problem of degradation in calibration precision since density had changed according to the positional relationship between an image of calibration-use pattern and a dither matrix. However, according to a density calibration method of the present invention, such change in density is reduced so that calibration precision can be enhanced. The invention may also be reduced to practice in other forms, for example, a dither matrix, a dither matrix generating device, a printing device or printing method employing a dither matrix, a method of generating printed matter, a computer program for implementing the functions of such method or device by means of a computer, or a recording medium having such a computer program recorded thereon. The use of a dither matrix in a printing device, printing method, or method of generating printed matter permits the dot on/off state of pixels to be determined through comparison on a pixel-by-pixel basis of threshold values established in the dither matrix to the tone values of image data; however, it would also be acceptable to determine the dot on/off state by comparing the sum of threshold value and tone value to a fixed value, for example. It would also be acceptable to determine dot on/off state according to tone values, and data created previously on the basis of threshold values, rather than using threshold values directly. Generally speaking, the dither method of the invention can be any method that permits dot on/off state to be determined according the tone values of pixels, and threshold values established at corresponding pixel locations in a dither matrix.
|
BACKGROUND 1. Technical Field The present invention relates to technology for printing images by forming dots on a printing medium. 2. Related Art Printing devices that perform printing by using print heads while performing scans in main scanning direction and sub scanning direction include inkjet printers such as serial scan type printers, drum scan type printers, and the like. The inkjet printers form characters and images on printing media by ejecting inks from a plurality of nozzles of print heads. One of dot recording modes employed by the inkjet printers is a mode referred to as “interlace mode”. FIG. 27 is an illustration depicting how sub scan feed is performed in an interlace recording mode. A print head 1000 has four nozzles arranged in sub scanning direction. Numbers 0-3 indicated in circles are nozzle numbers. The nozzles are arranged at a pitch k of three dots in the sub scanning direction. Here, a unit of [dot] means a dot pitch [inch] in the sub scanning direction equivalent to a print resolution. Positions of the print head 1000 indicated as pass 1, pass 2, and so on in FIG. 27 represent positions in the sub scanning direction at the time of each main scan. Here, the “pass” means one main scan. After each main scan, a sub scan feed of a fixed feed amount L of four dots is executed. However, positions of dots formed by each nozzle may sometimes be misaligned in some degree in the sub scanning direction due to manufacturing error of nozzle. A dot pattern Dtp1 of FIG. 27 is obtained under assumption that no such manufacturing error exists and all dot positions are normal. On the other hand, in case where dots formed by e.g. a first nozzle are misaligned upwards, there may be a space between a main scan line that has dots formed by the first nozzle and a main scan line that has dots formed by a zero nozzle, as shown in a dot pattern Dtp2 of FIG. 27. Such space may be observed by the naked eye as a portion of degraded image quality appearing as a streak, and is referred to as “banding”. The banding may be attributed not only to the manufacturing error of nozzle but also to several factors including error in sub scan feed, warpage of printing paper, and the like. In order to suppress such banding, a technique that performs correction by biasing density of each raster line is proposed (Patent Document 1). Specifically, in the example of the dot pattern Dtp2 of FIG. 27, the technique makes degradation of image quality appearing as a streak less noticeable by correcting and increasing densities of raster lines 6, 7 as well as by correcting and reducing densities of raster lines 4, 5. In JP-A-2005-219286, a technique that performs a smoothing process of correction value based on densities of a plurality of neighboring raster lines is further proposed. Conventional techniques are under assumption that density of each raster line is reproduced accurately as long as no error exists in landing position of ink droplet, amount of ink, and the like. However, no consideration has been given to accuracy of density of each raster line in such case of no error. Furthermore, such problem has occurred not only as the problem of banding that is now becoming obvious, but also as a wider range of problem including irregularity of density, fidelity of color reproduction, and the like. In addition, such problem has been occurring not only in inkjet printers but also in laser printers. SUMMARY An advantage of some aspect of the invention is to provide a technique for reducing uneven print density in a halftone process. According to an aspect of the invention, there is provided a printing method of printing on a printing medium. The method includes: generating dot data that represents state of dot formation at each print pixel of a print image to be formed on the printing medium by performing a halftone process on image data that represents an input tone value of each pixel making up an original image; and generating the print image by forming dots on each of the print pixels according to the dot data. The halftone process determines the state of dot formation by using a dither matrix that stores a plurality of threshold values, the plurality of threshold values being used for determining state of dot formation at each of print pixels of the print image to be formed on the printing medium according to an input tone value. The dither matrix is a matrix that stores each of the plurality of threshold values in each element such that a mutual difference in dot density formed at each predetermined print pixel group according to each input tone value falls within a predetermined range. The predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements. According to a printing device of the present invention, since dots can be formed such that difference in dot density formed at each predetermined print pixel group according to each input tone value falls within a predetermined range, a halftone process can be realized in such a way that reduces partial or local irregularity of density in a print image. Such reduction of density irregularity not only allows for improvement of fidelity of tone representation in a print image in monochromic printing and color printing, but also allows for reduction of deviation in hue by virtue of fidelity of density of each ink color. Here, the “dot density” means a product of a dot recording rate and a dot area, where the dot recording rate is a value obtained by dividing a number of dots formed by a number of pixels. Note that in case where plural sizes of dots are formed, the dot density is calculated by adding each product of a dot recording rate and a dot area with respect to each dot size. Note that in techniques disclosed in JP-A-2005-236768 and JP-A-2005-269527 that employ intermediate data (number data) for specifying state of dot formation, the use of dither matrix in the present invention has a broader concept that also includes the use of conversion table (or correspondence relationship table) generated using a dither matrix. Such conversion table is not only generated directly from a dither matrix generated by a generation method of the present invention, but may sometimes be adjusted or modified as well, and such cases also fall under the category of dither matrix generated by the generation method of the present invention. The invention also provides a density calibration method of generating correction data for calibrating image density printed on a printing medium. The method includes: generating dot data that represents state of dot formation, by using a dither matrix that stores a plurality of threshold values, the plurality of threshold values being used for determining state of dot formation at each of print pixels of a print image to be formed on a printing medium, according to calibration-use pattern data that includes uniform density image data generated by a uniform input tone value; forming dots on the printing medium according to the generated dot data; measuring density of the printed uniform density image with respect to each predetermined print pixel group; and generating correction data with respect to each predetermined region according to the measured density, the correction data including a correction value for reducing dispersion of density in the uniform density image. The program includes a program for causing the computer to determine the storage element such that a mutual difference in dot density formed among the plurality of predetermined print pixel groups according to each input tone value falls within a predetermined range. The predetermined print pixel group is a cluster of plural print pixels corresponding to each of a plurality of element groups that are created by dividing the dither matrix into preset numbers of elements. In a density calibration method that employs a conventional dither matrix, there has been a problem of degradation in calibration precision since density had changed according to the positional relationship between an image of calibration-use pattern and a dither matrix. However, according to a density calibration method of the present invention, such change in density is reduced so that calibration precision can be enhanced. The invention may also be reduced to practice in other forms, for example, a dither matrix, a dither matrix generating device, a printing device or printing method employing a dither matrix, a method of generating printed matter, a computer program for implementing the functions of such method or device by means of a computer, or a recording medium having such a computer program recorded thereon. The use of a dither matrix in a printing device, printing method, or method of generating printed matter permits the dot on/off state of pixels to be determined through comparison on a pixel-by-pixel basis of threshold values established in the dither matrix to the tone values of image data; however, it would also be acceptable to determine the dot on/off state by comparing the sum of threshold value and tone value to a fixed value, for example. It would also be acceptable to determine dot on/off state according to tone values, and data created previously on the basis of threshold values, rather than using threshold values directly. Generally speaking, the dither method of the invention can be any method that permits dot on/off state to be determined according the tone values of pixels, and threshold values established at corresponding pixel locations in a dither matrix. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating the configuration of a printing system in the embodiments. FIG. 2 is a schematic illustration of a color printer 20. FIG. 3 is an illustration of a nozzle arrangement on the lower face of print heads 10, 20. FIG. 4 shows an illustration depicting conceptually part of an exemplary dither matrix. FIG. 5 shows an illustration depicting the concept of dot on/off states using a dither matrix. FIG. 6 shows an illustration depicting conceptually exemplary spatial frequency characteristics of threshold values established at pixels in a blue noise dither matrix having blue noise characteristics. FIG. 7 shows a conceptual illustration of a visual spatial frequency characteristic VTF (Visual Transfer Function) representing acuity of the human visual faculty with respect to spatial frequency. FIG. 8 shows a mechanism by which local density irregularity is produced due to use of a conventional dither matrix. FIG. 9 shows dot patterns subjected to a halftone process which uses a plurality of conventional dither matrices arranged with shifts in sub scanning direction. FIG. 10 is a flowchart showing the processing routine of a method of dither matrix generation in a first embodiment of the present invention. FIG. 11 is a flowchart showing the processing routine of a storage element determination process in the first embodiment of the present invention. FIG. 12 shows a matrix MG24 in which threshold values associated with the first to twenty-fifth greatest tendency to dot formation are stored and dots formed on each of 25 pixels that correspond to these elements. FIG. 13 is a flowchart showing the processing routine of a candidate storage element selection process in the first embodiment of the present invention. FIG. 14 shows row-wise numbers of already determined threshold values and column-wise numbers of already determined threshold values. FIG. 15 shows a state in which a dot that corresponds to a candidate storage element and dots that correspond to already determined threshold values are made on (dot pattern Dpa1). FIG. 16 shows a dot density matrix Dda1 that represents a dot density in a quantitative manner. FIG. 17 shows a guideline for determining a target of a region division process in a second embodiment of the present invention. FIG. 18 shows examples of element groups that were established based on the guideline of the second embodiment of the present invention. FIG. 19 shows an illustration of an exemplary print image generating process in the embodiments. FIG. 20 shows an illustration depicting creation of a printed image on a printing medium in the embodiments by means of combining print pixels that belong to multiple pixel groups in a common printing region. FIG. 21 is a flowchart showing the processing routine of a storage element determination process in a third embodiment of the present invention. FIG. 22 is a flowchart showing the processing routine of an evaluation value determination process in the third embodiment of the present invention. FIG. 23 shows an illustration depicting a dither matrix M subjected to a grouping process in the embodiment. FIG. 24 shows an illustration depicting four divided matrices M1-M4 in the embodiment. FIG. 25 shows an illustration depicting four dot patterns formed on print pixels belonging respectively to first to fourth pixel groups, among elements storing the threshold values associated with the first to eighth greatest tendency to dot formation in a dither matrix M. FIG. 26 shows an illustration depicting dot density matrices that correspond respectively to the four dot patterns. FIG. 27 shows how banding is produced in an interlace recording mode. DESCRIPTION OF EXEMPLARY EMBODIMENTS The embodiments of the present invention will be described below in the following order, for the purpose of providing a clearer understanding of the operation and working effects of the present invention. A. One Example of Printing System Configuration: B. Production of Density Irregularity Due to Conventional Dither Matrix: C. Method of Dither Matrix Generation in First Embodiment of Present Invention: D. Method of Dither Matrix Generation in Second Embodiment of Present Invention: E. Method of Dither Matrix Generation in Third Embodiment of Present Invention: F. Modifications: A. Configuration of Printing System in the Embodiments: FIG. 1 is a block diagram illustrating the Configuration of a printing system in the embodiments. This printing system is furnished with a computer 90 as a printing control device, and a color printer 20 as a print unit. The color printer 20 and the computer 90 can be termed a “printing device” in the broad sense. On the computer 90, an application program 95 runs on a prescribed operating system. The operating system incorporates a video driver 91 and a printer driver 96; print data PD for transfer to the color printer 20 is output from the application program 95 via these drivers. The application program 95 performs the desired processing of images targeted for processing, as well as outputting images to a CRT 21 via the video driver 91. Within the printer driver 96 are a resolution conversion module 97 for converting the resolution of an input image to the resolution of the printer; a color conversion module 98 for color conversion from RGB to CMYK; a halftone module 99 that, using an error diffusion method and/or the dither matrices M generated in the embodiments to be discussed later, performs halftone process of input tone values and transform them into output tone values representable by forming dots; a print data generating module 100 that uses the halftone data for the purpose of generating print data to be sent to the color printer 20; a color conversion table LUT serving as a basis for color conversion by the color conversion module 98; and a recording rate table DT for determining recording rates of dots of each size, for the halftone process. The printer driver 96 corresponds to a program for implementing the function of generating the print data PD. The program for implementing the functions of the printer driver 96 is provided in a format recorded on a computer-readable recording medium. Examples of such a recording medium are a CD-ROM 126, flexible disk, magneto-optical disk, IC card, ROM cartridge, punch card, printed matter having a bar code or other symbol imprinted thereon, a computer internal memory device (e.g. RAM, ROM, or other memory) or external memory device, or various other computer-readable media. FIG. 2 is a schematic illustration of the color printer 20. The color printer 20 is equipped with a sub-scan driving portion for transporting printing paper P in the sub-scanning direction by means of a paper feed motor 22; a main scan driving portion for reciprocating a carriage 30 in the axial direction of a paper feed roller 26 (main scanning direction) by means of a carriage motor 24; a head drive mechanism for driving a print head unit 60 installed on the carriage 30 (also termed the “print head assembly”) and controlling ink ejection and dot formation; and a control circuit 40 for exchange of signals with the paper feed motor 22, the carriage motor 24, the print head unit 60 equipped with the print heads 10, 12, and a control panel 32. The control circuit 40 is connected to the computer 90 via a connector 56. FIG. 3 is an illustration of the nozzle arrangement on the lower face of the print heads 10, 12. On the lower face of the print head 10 there are formed a black ink nozzle group K for ejecting black ink, a cyan ink nozzle group C for ejecting cyan ink, a magenta ink nozzle group Mz for ejecting magenta ink, and a yellow ink nozzle group Y for ejecting yellow ink. The plurality of nozzles contained in each nozzle group are respectively lined up at a constant nozzle pitch k·D, in the sub-scan direction. Here, k is an integer, and D represents pitch equivalent to the print resolution in the sub-scan direction (also termed “dot pitch”). This will also referred to herein as “the nozzle pitch being k dots.” The “dot” unit means the dot pitch of the print resolution. Similarly, sub-scan feed distance is also expressed in “dot” units. Each nozzle Nz is provided with a piezo element (described later) for the purpose of driving the nozzle Nz and ejecting drops of ink. During printing, ink drops are ejected from the nozzles as the print heads 10, 12 are scanned in the main scanning direction MS. FIG. 4 shows an illustration depicting conceptually part of an exemplary dither matrix M. The illustrated dither matrix contains threshold values selected evenly from a tone value range of 1 to 255, stored in a total of 16384 elements, i.e. 128 elements in the horizontal direction (main scanning direction) and 64 elements in the vertical direction (sub-scan direction). The size of the dither matrix M is not limited to that shown by way of example in FIG. 4; various other sizes are possible, including matrices having identical numbers of horizontal and vertical elements. FIG. 5 shows an illustration depicting the concept of dot on/off states using a dither matrix. For convenience in illustration, only a portion of the elements are shown. As depicted in FIG. 5, when determining dot on-off states, tone values contained in the image data are compared with the threshold values saved at corresponding locations in the dither matrix. In the event that a tone value contained in the image data is greater than the corresponding threshold value stored in the dither table, a dot is formed; if the tone value contained in the image data is smaller, no dot is formed. Pixels shown with hatching in FIG. 5 signify pixels targeted for dot formation. By using a dither matrix in this way, dot on-off states can be determined on a pixel-by-pixel basis, by a simple process of comparing the tone values of the image data with the threshold values established in the dither matrix, making it possible to carry out the tone number conversion process rapidly. Furthermore, once image data tone values have been determined, decisions as to whether to form dots on pixels will be made exclusively on the basis of the threshold values established in the matrix, and from this fact it will be apparent that with a systematic dither process it is possible to actively control dot production conditions by means of the threshold value storage locations established in the dither matrix. Since with a systematic dither process it is possible in this way to actively control dot production conditions by means of the storage locations of the threshold values established in the dither matrix M, a resultant feature is that dot dispersion and other picture qualities can be controlled by means of adjusting the settings of the threshold value storage locations. This means that by means of a dither matrix optimization process, it is possible to optimize the halftoning process for a wide variety of target states. FIG. 6 shows an illustration depicting conceptually exemplary spatial frequency characteristics of threshold values established at pixels in a blue noise dither matrix having blue noise characteristics, by way of a simple example of adjustment of dither matrix. The spatial frequency characteristics of a blue noise dither matrix are characteristics such that the length of one cycle has the largest frequency component in a high frequency region of close to two pixels. These spatial frequency characteristics have been established in consideration of the characteristics of human visual perception. Specifically, a blue noise dither matrix M is a dither matrix in which, in consideration of the fact that human visual acuity is low in the high frequency region, the storage locations of threshold values have been adjusted in such a way that the largest frequency component is produced in the high frequency region. FIG. 6 also shows exemplary spatial frequency characteristics of a green noise matrix M, indicated by the broken line curve. As illustrated in the drawing, the spatial frequency characteristics of a green noise dither matrix are characteristics such that the length of one cycle has the largest frequency component in an intermediate frequency region of from two to ten or so pixels. Since the threshold values of a green noise dither matrix are established so as to produce these sorts of spatial frequency characteristics, if dot on/off states of pixels are decided while looking up in a dither matrix having green noise characteristics, dots will be formed adjacently in units of several dots, while at the same time the clusters of dots will be formed in a dispersed pattern overall. For printers such as laser printers, with which it is difficult to consistently form fine dots of about one pixel, by means of deciding dot on/off states of pixels through lookup in such a green noise matrix it will be possible to suppress formation of “orphan” dots. As a result, it will be possible to output images of consistently high quality at high speed. In other words, a dither matrix adapted for lookup to decide dot on/off states in a laser printer or similar printer will contain threshold values adjusted so as to have green noise characteristics. FIG. 7 shows conceptual illustrations of a visual spatial frequency characteristic VTF (Visual Transfer Function) representing human visual acuity with respect to spatial frequency. Through the use of a visual spatial frequency characteristic VTF it will be possible to quantify the perception of graininess of dots apparent to the human visual faculty following the halftone process, by means of modeling human visual acuity using a transfer function known as a visual spatial frequency characteristic VTF. A value quantified in this manner is referred to as a graininess index. Formula Fl gives a typical experimental equation representing a visual spatial frequency characteristic VTF. In Formula F1 the variable L represents observer distance, and the variable u represents spatial frequency. Formula F2 gives an equation defining a graininess index. In Formula F2 the coefficient K is a coefficient for matching derived values with human acuity. Such quantification of graininess perception by the human visual faculty makes possible fine-tuned optimization of a dither matrix for the human visual system. Specifically, a Fourier transform can be performed on a dot pattern hypothesized when input tone values have been input to a dither matrix, to arrive at a power spectrum FS; and a graininess evaluation value that can be derived by integrating all input tone values after multiplying the power spectrum FS with the visual spatial frequency characteristic VTF (Formula F2) can be utilized as a evaluation coefficient for the dither matrix. In this example, the aim is to achieve optimization by adjusting threshold value storage locations to minimize the dither matrix evaluation coefficient. The feature that is common to such dither matrices established in consideration of the characteristics of human visual perception such as the blue noise matrix and the green noise matrix is that, on a printing medium, an average value of components within a specified low frequency range is set small, where the specified low frequency range is a spatial frequency domain within which visual sensitivity of human is at a highest level and ranges from 0.5 cycles per millimeter to 2 cycles per millimeter with a central frequency of 1 cycle per millimeter. For example, the inventors have ascertained that, by configuring a matrix to have such a frequency characteristic that the average value of components within the specified low frequency range is smaller than an average value of components within another frequency range, where the another frequency range is a domain within which visual sensitivity of human is reduced to almost zero and ranges from 5 cycles per millimeter to 20 cycles per millimeter with a central frequency of 10 cycles per millimeter, it is possible to reduce granularity in a domain within which visual sensitivity of human is at a high level, thereby effectively improving image quality with a focus on visual sensitivity of human. However, in conventional dither matrices, although dispersion of dots and fidelity of tone representation have been considered in a global scale, however, partial or local fidelity of tone representation has not been considered. B. Production of Density Irregularity Due to Conventional Dither Matrix: FIG. 8 is an illustration depicting a mechanism by which local density irregularity is produced due to use of a conventional dither matrix. In FIG. 8, a dot pattern Dpm1 formed by using a dither matrix M is shown. Here, suppose an input tone value is 64, i.e. a value equivalent to 25% of a maximum tone value, then a number of dots that should be formed on each raster line is 64. However, by focusing attention on three lines RL1, RL2, RL3 in main scanning direction, numbers of dots formed on these lines are 74, 52, and 64, respectively. These dots correspond to tone values of 74, 52, and 64, respectively. The reason such deviation in tone has occurred is that the conventional dither matrix is generated in consideration of global fidelity of tone representation, rather than local fidelity of tone representation. Such deviation in tone on each raster line has become obvious as banding, in combination not only with manufacturing error of nozzle (error in ink flight direction, error in ink amount, and the like), but also with factors such as error in sub scan feed and warpage of printing paper. On the other hand, the local irregularity of density has also occurred as unexplained irregularity of density, hue, and the like in a portion that should be monotone under normal conditions. FIG. 9 is an illustration showing dot patterns subjected to a halftone process which uses a plurality of conventional dither matrices arranged with shifts in sub scanning direction. Such shifts of dither matrices are made for the purpose of, for example, reducing low frequency noises that may be produced in cycles of the dither matrix arrangement and thereby improving image quality. The reason the low frequency noises are produced in cycles of the dither matrix arrangement is that performing a halftone process using the same dither matrix and the same tone value may cause dots to be formed at the same position in the dither matrix. As can be seen from FIG. 9, nine lines in main scanning direction RL1a, RL2a, RL3a, RL1b, RL2b, RL3b, RL1c, RL2c, and RL3c included in three dot patters Dpm1a, Dpm1b, and Dpm1c are connected at positions deviated from each other in the sub scanning direction. For example, the raster line RL3a of the dot pattern Dpm1a is connected with the raster line RL2b of the dot pattern Dpm1b and the raster line RL1c of the dot pattern Dpm1c. Meanwhile, since the lines in the main scanning direction RL3a, RL2b, and RL1c respectively represent densities corresponding to tone values of 64, 52, and 74, it is found that there is irregularity of density produced on a single raster line. Such irregularity of density cannot be solved by such a technique as disclosed in JP-A-2005-219286 which applies a process of density correction to every single raster line. The inventors of the present application successively unlocked the mechanism of density irregularity production and created an invention for solving such problem. The present invention is disclosed by each embodiment which will be described later. Furthermore, the inventors of the present application ascertained that the mechanism of density irregularity production also works similarly in printers that form dots on printing media while performing sub scanning of paper feed, such as line printers, well-known LED printers, and the like, to appear as density irregularity on each sub scan line. Note that in such printers, the scanning (paper feed) is performed only in the main scanning direction in FIG. 9. Furthermore, since in such printers, dither matrices are arranged with shifts in sub scanning direction for the purpose of improving image quality as shown in FIG. 9, density of each sub scan line i.e. a cluster of dots neighboring in the sub scanning direction may change depending on its position of sub scan. The reduction of density irregularity in this way can prevent the density of each sub scan line from being changed depending on its position of sub scan, thereby significantly improving image quality. C. Method of Dither Matrix Generation in First Embodiment of Present Invention FIG. 10 is a flowchart showing the processing routine of a method of dither matrix generation in a first embodiment of the present invention. In this example, a small dither matrix of 10 rows and 10 columns is generated for ease of explanation. A graininess index (Formula F2, FIG. 7) is used as an evaluation for representing optimality of dither matrix. In step S100, a region division process is performed. The region division process is a process of dividing a dither matrix into a predetermined plural regions for the purpose of reducing local irregularity of density. Details of this process will be described later. Each of the plural regions is composed as a group of elements including a plurality of elements. Note that in the present embodiment, the group of elements corresponds to “each of a plurality of element groups” in the scope of claim for patent. In step S200, a target threshold value determination process is performed. The target threshold value determination process is a process of determining a threshold value that is targeted for determination of storage element. In the present embodiment, the determination of threshold value is performed by selecting threshold values in ascending order, i.e. in order of decreasing tendency to dot formation. Selecting threshold values in order of decreasing tendency to dot formation allows threshold values to have its storage elements determined in order of decreasing conspicuity of dot graininess, i.e. level of highlight, of regions for which the threshold values are used to control dot arrangements. It is thus possible to provide greater degrees of design freedom to highlight regions having conspicuous dot graininess. In step S300, a storage element determination process is performed. The storage element determination process is a process of determining an element for storing a target threshold value. A dither matrix is generated by alternately repeating these target threshold value determination process (step S200) and storage element determination process (step S300). The target threshold value may be all threshold values, or alternatively be a part of threshold values. FIG. 11 is a flowchart showing the processing routine of a storage element determination process in the first embodiment of the present invention. In step S310, each dot that corresponds to an already determined threshold value is made on. The already determined threshold value indicates a threshold value for which a storage element is determined. In the present embodiment, since threshold values are selected in order of decreasing tendency to dot formation as described above, at the time when a dot that corresponds to a target threshold value is formed, every pixel that corresponds to an element storing an already determined threshold value will have a dot formed thereon. To the contrary, in case where an input tone value is a minimum value that allows for formation of dot in association with a target threshold value, any pixel that corresponds to an element other than those storing already determined threshold values will not have a dot formed thereon. FIG. 12 is an illustration depicting a matrix MG24 in which threshold values (from 0 to 24) associated with the first to twenty-fifth greatest tendency to dot formation are stored and dots formed on each of 25 pixels that correspond to these elements. A dot pattern Dpa thus configured is used to determine on which pixel a twenty-sixth dot is to be formed. In step S320, a candidate storage element selection process is performed. The candidate storage element selection process is a process of selecting a candidate storage element in such a way that prevents variation in number of dots formed on each print pixel group corresponding to each element group described above from becoming too large. FIG. 13 is a flowchart showing the processing routine of a candidate storage element selection process in the first embodiment of the present invention. In step S322, a row-wise minimum number Rmin which is a minimum number of already determined threshold values in the row-wise direction of the dither matrix M and a column-wise minimum number Cmin which is a minimum number of already determined threshold values in the column-wise direction of the dither matrix M are calculated. FIG. 14 is an illustration showing row-wise numbers of already determined threshold values and column-wise numbers of already determined threshold values. As can be seen from FIG. 14, three threshold values of 17, 19, and 12 are stored in each element in the first column; whereas only one threshold value of 16 is stored in each element in the fourth column. On the other hand, three threshold values of 17, 7, and 14 are stored in each element in the first row; whereas two threshold values of 1 and 24 are stored in each element in the second row. Based on these respective numbers of already determined threshold values, the number of threshold values “1” in the fourth column is determined as the column-wise minimum number Cmin, and the number of threshold values “2” in the second row and the like is determined as the row-wise minimum number Rmin. In step S324, a target element selection process is performed. The target element selection process is a process of selecting storage elements, in which already determined threshold values are not stored, in a predetermined order. In the present embodiment, storage elements are selected on a column-by-column basis starting from the first column. For example, an element in the second column of the first row attached with a mark “*1” is selected as a first target pixel, followed by an element in the third column of the first row (*2), an element in the fourth column of the first row (*3), and so on. In step S326, a difference calculation process is performed. The difference calculation process is a process of calculating a row-wise difference value Diff_R between a row-wise number of already determined threshold values Rtarget in the row the target element belongs and the row-wise minimum number Rmin and a column-wise difference value Diff_C between a column-wise number of already determined threshold values Ctarget and the column-wise minimum number Cmin. For example, in case where the target element is an element in the second column of the first row, the row-wise number of already determined threshold values Rtarget is “3” and the row-wise minimum number Rmin is “2”, so that the row-wise difference value Diff_R is “1”. On the other hand, the column-wise number of already determined threshold values Ctarget is “3” and the column-wise minimum number Cmin is “1”, so that the column-wise difference value Diff_C is “2”. In step S328, a determination is made as to whether or not both the column-wise difference value Diff_C and the row-wise difference value Diff_R are less than respective predetermined criterion values. As a result of the determination, if the row-wise difference value Diff_R is less than a criterion value N and the column-wise difference value Diff_C is less than a criterion value M, the control of the process is passed to step S329. On the other hand, if any one of the difference values is equal to or greater than its corresponding criterion value, then the control of the process is returned to step S322. For example, in case where both the criterion values N, M are “1”, it is found that elements such as the one in the second column of the first row and the one in the third column of the first row will result in difference values of equal to or greater than the criterion value but the element in the fourth column of the first row will result in a difference value of less than the criterion value. In step S329, the target element is replaced by the candidate storage element. In this way, only those elements that give a difference value, i.e. a difference between a number of already determined threshold values of the row and the column to which the target element belongs and a minimum number of threshold values of the row and column, of less than a criterion value will be selected as the storage element. Specifically, irrespective of row number, only those elements that respectively belong to the fourth column, seventh column, ninth column, and tenth column (elements with hatchings) will be selected as the candidate storage element. Once step S329 is complete, the control of the process is returned to step S330 (FIG. 11). In step S330, a dot that corresponds to the candidate storage element is made on. This process is performed in such a way that adds a dot to a group of dots that were made on in step S310 as dots that correspond to already determined threshold values. FIG. 15 is an illustration depicting a state in which a dot that corresponds to the candidate storage element and dots that correspond to the already determined threshold values are made on (dot pattern Dpa1). Here, the candidate storage element is an element in the seventh column of the first row. FIG. 16 is an illustration depicting a matrix that digitizes this state, that is to way, a dot density matrix Dda1 that represents a dot density in a quantitative manner is depicted. The numeral “0” indicates no dot has been formed; whereas the numeral “1” indicates a dot has been formed (including the case where a dot is assumed to be formed in the candidate storage element). In step 340, an evaluation value determination process is performed. The evaluation value determination process is a process of calculating a graininess index as an evaluation value, based on this dot density matrix (FIG. 16). The graininess index can be calculated by using a computational equation shown in FIG. 7. Note that the graininess index regarding the above-described predetermined element group may also be included in the evaluation value. In step S350, the graininess index calculated this time is compared to the graininess index calculated last time (stored in a buffer not shown). As a result of the comparison, if the graininess index calculated this time is smaller (more preferable), then the buffer is stored (updated) with the graininess index of this time in association with the candidate storage element, and the candidate storage element of this time is tentatively considered as the storage element (step S360). Such process is performed for every candidate element, and a candidate storage element that is stored in the buffer (not shown) in the final stage is determined as the storage element (step S370). Furthermore, such process is performed for every threshold value or alternatively for every threshold value within a preset range, thereby completing the dither matrix generation process (step S400, FIG. 10). As described above, in the first embodiment, since difference in number of dots formed in each row and each column according to each tone value is restricted within a predetermined range, it is possible to reduce local density irregularity and thereby enhance image quality. Furthermore, since density error of each raster line is reduced, there is also an advantage of suppressing banding. Note that in the present embodiment, the graininess index corresponds to the “matrix evaluation value that represents correlation to a predetermined target state” in the scope of claim for patent. Meanwhile, in the present embodiment, the “predetermined target state” means that the graininess index of state of dot formation is small. D. Method of Dither Matrix Generation in Second Embodiment of Present Invention: FIG. 17 is an illustration showing a guideline for determining a target of a region division process in a second embodiment of the present invention. The guideline is quantified by a VTF function by using human visual perception as a criterion. For example, suppose a print resolution is 720 DPI and a value that makes the VTF function to be 0.2 is used as the criterion, then it is found that a matrix can be divided into regions of 6 pixel size (<6.59=720/(4.3×25.4)). FIG. 18 is an illustration showing examples of element groups that were established based on the above-described guideline. An element group Pg1 is configured as an element group of 6 rows and 6 columns; an element group Pg2 is configured as an element group of 5 rows and 2 columns; and an element group Pg3 is configured as an element group of 6 rows and 1 column, respectively. Although in this example, both row-wise size and column-wise size of each element group are within 6 pixels; however, only one of row-wise size and column-wise size may be within 6 pixels, such as the element group of 1 pixel row and 256 pixels column as in the first embodiment. As described above, the inventors of the present application discovered to use human visual perception also as a criterion for the guideline of dither matrix division process. Based on such criterion, the inventors of the present invention discovered that determining, according to a size of the print pixel, a number of elements belonging to each of the plurality of divided regions such that change of size of print pixel group along with change of print resolution can be small allows the invention of the present application to comply with various print resolutions while maintaining its effects as well. E. Method of Dither Matrix Generation in Third Embodiment of Present Invention: FIG. 19 shows an illustration of an exemplary print image generating process in the third embodiment. The print image is generated on the print medium by forming black ink dots while performing main scanning and sub scanning in this image forming methods for easy-to-follow explanation. The main scan means the operation of moving the printing head 10 (FIG. 3) relatively in the main scanning direction in relation to the print medium. The sub scan means the operation of moving the printing head 10 relatively in the sub scanning direction in relation to the print medium. The printing head 10 is configured so as to form ink dots by spraying ink drops on the print medium. The printing head 10 is equipped with ten nozzles that are not illustrated at intervals of 2 times the pixel pitch k. Generation of the print image is performed as follows while performing main scanning and sub scanning. Among the ten main scan lines of raster numbers 1, 3, 5, 7, 9, 11, 13, 15, 17, and 19, ink dots are formed at the pixels of the pixel position numbers 1, 3, 5, and 7. The main scan line means the line formed by the continuous pixels in the main scanning direction. Each circle indicates the dot forming position. The number inside each circle indicates the pixel groups configured from the plurality of pixels for which ink dots are formed simultaneously. With pass 1, dots are formed on the print pixels belong to the first pixel group. When the pass 1 main scan is completed, the sub scan sending is performed at a movement volume Ls of 3 times the pixel pitch in the sub scanning direction. Typically, the sub scan sending is performed by moving the print medium, but with this embodiment, the printing head 10 is moved in the sub scanning direction to make the description easy to understand. When the sub scan sending is completed, the pass 2 main scan is performed. With the pass 2 main scan, among the ten main scan lines for which the raster numbers are 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24, ink dots are formed at the pixels for which the pixel position number is 1, 3, 5, and 7. Working in this way, with pass 2, dots are formed on the print pixels belonging to the second pixel group. Note that the two main scan lines for which the raster numbers are 22 and 24 are omitted in the drawing. When the pass 2 main scan is completed, after the sub scan sending is performed in the same way as described previously, the pass 3 main scan is performed. With the pass 3 main scan, among the ten main scan lines including the main scan lines for which the raster numbers are 11, 13, 15, 17, and 19, ink dots are formed on the pixels for which the pixel position numbers are 2, 4, 6, and 8. With the pass 4 main scan, among the ten main scan lines including the three main scan lines for which the raster numbers are 16, 18, and 20, ink dots are formed on the pixels for which the pixel position numbers are 2, 4, 6, and 8. Working in this way, we can see that it is possible to form ink dots without gaps in the sub scan position from raster number 15 and thereafter. With pass 3 and pass 4, dots are formed on the print pixels belonging respectively to the third and fourth pixel groups. When monitoring this kind of print image generation focusing on a fixed area, we can see that this is performed as noted below. For example, when the focus area is the area of pixel position numbers 1 to 8 with the raster numbers 15 to 19, we can see that the print image is formed as noted below at the focus area. With pass 1, at the focus area, we can see that a dot pattern is formed that is the same as the ink dots formed at the pixel positions for which the pixel position numbers are 1 to 8 with the raster numbers 1 to 8. This dot pattern is formed by dots formed at the pixels belonging to the first pixel group. Specifically, with pass 1, for the focus area, dots are formed at pixels belonging to the first pixel group. With pass 2, at the focus area, dots are formed at the pixels belonging to the second pixel group. With pass 3, at the focus area, dots are formed at the pixels belonging to the third pixel group. With pass 4, at the focus area, dots are formed at the pixels belonging to the fourth pixel group. In this way, the monochromatic print with this embodiment, we can see that the dots formed at the print pixels belonging to each of the plurality of first to fourth pixel groups are formed by mutually combining in the common print region. Meanwhile, in color printing color printed images are formed by means of ejecting ink of the colors C, Mz, Y and K from the ink head (FIG. 3), onto each of the first to fourth multiple pixel groups, in the same manner. FIG. 20 shows an illustration depicting creation of a printed image on a printing medium in the third embodiment by means of combining, into a common printing region, print pixels that belong to multiple pixel groups. In the example of FIG. 20, the printed image is a printed image of prescribed intermediate tone (monochrome). The dot patterns DP1, DP1a are dot patterns formed on a plurality of pixels belonging to a first pixel group. The dot patterns DP2, DP2a are dot patterns formed on a plurality of pixels belonging to the first and a second pixel group. The dot patterns DP3, DP3a are dot patterns formed on a plurality of pixels belonging to the first to third pixel groups. The dot patterns DP4, DP4a are dot patterns formed on a plurality of pixels belonging to all of the pixel groups. The dot patterns DP1, DP2, DP3, DP4 are dot patterns obtained where a conventional dither matrix is used. The dot patterns DP1a, DP2a, DP3a, DP4a are dot patterns obtained where the dither matrix of the embodiment is used. As will be apparent from FIG. 20, where the dither matrix of the embodiment is used, dispersion of dots is more uniform than here a conventional dither matrix is used, especially for the dot patterns DP1a, DP2a having minimal overlap of dot pattern. Since conventional dither matrices lack the concept of pixel groups, optimization is carried out in a manner focused exclusively on dispersion of dots in the final printed image (in the example of FIG. 20, the dot pattern DP4). However, the inventors have carried out an analysis of image quality of printed images, focusing on the dot patterns in the course of the dot formation process. As a result of the analysis, it was found that image irregularity may arise during the dot formation process due to density level of dot patterns. The inventors discovered that such image irregularity occurs because dots of several colors formed during a given main scan pass do not overlap in a uniform manner, thus producing areas in which dots of several colors come into contact and bleed together and areas in which where dots of several colors remain separate and do not bleed together, occur in mottled patterns, which in turn causes irregular color. Such color irregularity may occur even where a printed image is formed in a single pass. However, even if color irregularity is produced uniformly throughout the entire image, it will nevertheless not be readily apparent to the human visual faculty. This is because, due to the fact that the irregularity occurs uniformly, ink bleed will not take the form of nonuniform “irregularity” that includes a low-frequency component. In a dot pattern composed of pixel groups in which ink dots are formed substantially simultaneously during a given main scan, if irregularity should happen to occur due to ink bleed in a low-frequency region that is readily noticeable to the human eye, marked degradation of image quality will become apparent. In this way, the inventors discovered for the first time that, where a printed image is produced by means of forming ink dots, high levels of image quality may be obtained if the dither matrix is optimized giving attention to the dot patterns formed in pixel groups in which ink dots are formed substantially simultaneously. The inventors further ascertained that degraded image quality of an extent highly noticeable to the human eye may result not only from ink bleed, but also from physical phenomena of the ink, such as ink agglomeration, irregular sheen, or bronzing. Bronzing is a phenomenon whereby, due to factors such as coagulation of dye in ink drops, the condition of reflected light on the printed paper surface varies so that, for example, the printed surface develops a bronze-colored appearance depending on the viewing angle. Furthermore, conventional dither matrices, attempt to achieve optimization on the assumption that positional relationships among pixel groups are the same as the ones posited in advance; thus, in the event that actual positional relationships should deviate, optimality can no longer be assured and appreciable degradation of image quality may result. However, experiments conducted by the inventors have shown for the first time that, with the dither matrix of the embodiment, due to the fact that dispersion of dots is assured in dot patterns within dot groups as well, a high level of robustness against such deviation in positional relationships can be assured. The inventors have furthermore found that this technical concept assumes increased importance as printing speed increases. This is because faster printing speed means that dots of the next pixel group are formed before there has been sufficient time for the ink to be absorbed. Based on this standpoint, the inventors of the present application created a dither matrix generation method that can reduce degradation of image quality caused by performing a plural times of scans to form ink dots in a common region on a printing medium to print an image. The inventors of the present application also found that the generation method can also be combined with each of the embodiments described above. FIG. 21 is a flowchart showing the processing routine of a storage element determination process in the third embodiment of the present invention. In the dither matrix generation method of the embodiment, it is configured such that optimization can be performed in consideration of dispersion of dots formed by each main scan (pass) in the print image generating process. In this example, a small dither matrix of 8 rows and 8 columns is generated for ease of explanation. A graininess index (Formula F2) is used as an evaluation value for representing optimality of the dither matrix, similarly to the first embodiment. The generation process of the third embodiment is configured by replacing step S320 (candidate storage element selection process) and step S340 (evaluation value determination process) in the generation process of the first embodiment (FIG. 11) with step S320a and step S340a, respectively. FIG. 22 is a flowchart showing the processing routine of an evaluation value determination process in the third embodiment of the present invention. The processing routine differs from the evaluation value determination process of the first embodiment in that dot patterns formed on a plurality of pixels belonging respectively to first to fourth pixel groups are also targeted for evaluation. In step S342, a graininess index calculation process is performed. This process is targeted at all pixels and is the same process as the graininess index calculation process in the first embodiment. In step S344, the graininess index calculation process is performed with respect to each pixel group. In this process, a graininess index is calculated based on dot patterns formed on a plurality of pixels belonging respectively to the first to fourth pixel groups. FIG. 23 is an illustration depicting a dither matrix M subjected to a grouping process in the third embodiment of the present invention. In this grouping process, the dither matrix M is divided into four pixel groups shown in FIG. 19. Each number marked on each element of the dither matrix M indicates the pixel group to which the element belongs. For example, an element in the first row of the first column belongs to the first pixel group (FIG. 19), and an element in the second row of the first column belongs to the second pixel group. FIG. 24 is an illustration depicting four divided matrices M1-M4 in the third embodiment of the present invention. The divided matrix M1 is composed of: a plurality of elements that correspond to pixels belonging to the first pixel group, among the elements of the dither matrix M; and blank elements i.e. a plurality of elements in blank. The blank element is an element in which no dot is formed irrespective of input tone value. The divided matrices M2, M3, and M4 are respectively composed of: a plurality of elements that correspond to pixels belonging to the second, third, and fourth pixel groups, among the elements of the dither matrix M; and blank elements. FIG. 25 is an illustration depicting four dot patterns Dp1, Dp2, Dp3, Dp4 formed in print pixels belonging respectively to first to fourth pixel groups, among elements storing the threshold values associated with the first to eighth greatest tendency to dot formation in the dither matrix M. In FIG. 25, a print pixel that corresponds to a candidate storage element is also indicated by the mark “*”. FIG. 26 is an illustration depicting dot density matrices Dd1, Dd2, Dd3, Dd4 that correspond respectively to the four dot patterns Dp1, Dp2, Dp3, Dp4. Graininess indices of the respective pixel groups are calculated based on the five dot density matrices Dda, Dd1, Dd2, Dd3, and Dd4 thus determined, similarly to the first embodiment. In step S348, a weighted addition process is performed. The weighted addition process is a process of assigning weights to the respective calculated graininess indices and then adding them together. The process is performed based on the computational equation shown in FIG. 22. Specifically, it is determined as a sum of: a value obtained by multiplying the graininess index Ga regarding all pixels by a weighting coefficient Wa (four, for example); and a value obtained by multiplying a sum of the four graininess indices G1, G2, G3, G4 respectively regarding the first to fourth pixel groups by a weighting coefficient Wg (one, for example). As described above, in the present embodiment, a dither matrix M is optimized in such a way that reduces graininess indices of a plurality of dot patterns respectively formed by each main scan. It is therefore possible to reduce degradation of image quality attributable to physical phenomenon of ink occurring mutually among the plurality of dot patterns respectively formed by each main scan. Such difference of main scan in process of dot formation corresponds to “physical difference” in the scope of claim for patent. The “physical difference” in the scope of claim for patent not only include any misalignment of dot due to error in mechanism of a printing device such as measuring error of print head position, measuring error of sub scan feed amount, and the like, but also has a broader meaning including factors such as misalignment of dot in main scanning direction due to uplift of a print paper, deviation (time lag) or sequence of ink ejection timing (temporal error), and the like. The positional misalignment of dot becomes obvious as, for example, positional misalignment between dots formed by forward pass of main scan by a print head and dots formed by backward pass of main scan by the print head in main scanning direction. F. Modifications: Although the present invention has been described above in terms of several embodiments, the present invention is not restricted to these embodiments, but may be implemented in various modes without departing from the scope of the present invention. For example, the present invention allows for optimization of dither matrix with respect to the following modifications. F-1. Although in above embodiments, it is configured such that difference in number of dots formed in each of element groups, which were made by dividing a dither matrix into groups having the same number of elements, falls within a predetermined range; however, it would be acceptable if difference in dot density falls within a predetermined range. Furthermore, as long as difference in dot density falls within a predetermined range, the predetermined element groups not necessarily have the same number of elements. Here, the “dot density” means a product of a dot recording rate and a dot area, where the dot recording rate is a value obtained by dividing a number of dots formed by a number of pixels. Note that, in case where plural sizes of dots are formed, the dot density is calculated by adding each product of a dot recording rate and a dot area with respect to each dot size. In case where only a single size of dot is formed, the dot density is a physical quantity that is substantially equivalent to the dot recording rate. F-2. Although in above embodiments, graininess index is used as a scale of dither matrix evaluation; however, it would also be acceptable to use other scales, for example, RMS granularity that will be described later. This scale of evaluation can be determined by subjecting dot density values to a low pass filtering process using a predetermined low pass filter and then calculating a standard deviation of the density values after the low pass filtering process. F-3. Although in above embodiments, indices such as graininess index and RMS granularity are used as an evaluation value for representing correlation with a predetermined target state; however, it would also be acceptable to use blue noise characteristics or green noise characteristics as a target state and optimize a dither matrix so as to bring its characteristic nearer to these characteristics. Furthermore, although in above embodiments, an evaluation value is determined by using a dot pattern of all pixels or dot patterns of respective pixel groups as target of evaluation; however, it would also be acceptable to include predetermined element groups as target of evaluation. F-4: Although in above embodiments, the evaluation process is performed each time a storage element for storing a threshold value is determined; however, the present invention would also be applicable to cases where storage elements for storing a plurality of threshold values are determined simultaneously at one time, for example. Specifically, for example, in case where storage elements of first to sixth threshold values have been determined and storage elements of seventh and eighth threshold values are now to be determined in above embodiments, storage elements of the seventh and eighth threshold values may be determined based on an evaluation value associated with the time a dot has been added to a storage element of the seventh threshold value and an evaluation value associated with the time dots have respectively been added to storage elements of the seventh and eighth threshold values, or alternatively, only a storage element of the seventh threshold value may be determined. F-5. In above embodiments, a dither matrix is generated by determining a target threshold value by selecting threshold values in ascending order i.e. in order of decreasing tendency to dot formation, and then, based on a matrix evaluation value that represents correlation with a predetermined target state and is calculated based on state of dot formation under the assumption that the target threshold value thus determined is stored in each element, determining a storage element for the target threshold value out of the plurality of candidate storage elements. However, such method is not restrictive, and it would also be acceptable to select threshold values in descending order. However, the method used in the embodiments is advantageous in that greater degrees of design freedom can be provided to highlight regions having conspicuous dot graininess. Furthermore, threshold values are not necessarily determined in sequence, but it would also be acceptable to generate a dither matrix by preparing a dither matrix as initial state, and determining each element for storing each threshold value while replacing a part of a plurality of threshold values stored in respective elements with different threshold value(s) stored in other element(s) . In this case, an evaluation function can be established by including difference in dot density formed in each of predetermined element groups into the evaluation function (punishment function). Note that a dot density matrix, which works as a criterion of evaluation, may be generated based on a minimum input tone value that allows for formation of dot in association with a target threshold value, or alternatively, may be generated based on an input tone value equal to or greater than the minimum input tone value. F-6. The present invention may also be reduced to practice as a density calibration device and a density calibration method that employ a dither matrix thus generated. For example, the present invention may be reduced to practice as a density calibration method that generates correction data for calibrating image density printed on a printing medium. In this density calibration method, dot data that represent state of dot formation is generated according to calibration-use pattern data that includes uniform density image data generated by a uniform input tone value, by using a dither matrix that is generated by the method disclosed in each of above embodiments, and then, dots are formed on a printing medium according to this dot data. Next, density of the uniform density image printed by a scanner (not shown) is measured with respect to each predetermined print pixel group, and according to the density thus measured, correction data that includes a correction value for reducing dispersion of density in the uniform density image may be generated with respect to each predetermined print pixel group. In a density calibration method that employs a conventional dither matrix, there has been a problem of degradation in calibration precision since density had changed according to the positional relationship between an image of calibration-use pattern and a dither matrix. However, according to a density calibration method of the present invention, such change in density can be reduced so that calibration precision can be enhanced. Furthermore, in the density calibration method of the invention of the present application, it would also be acceptable to consider a cluster of pixels neighboring in the main scanning direction (raster line) as a predetermined print pixel group. This reduces deviation in tone on each raster line, and thereby reduces banding that has become obvious in combination with factors such as manufacturing error of nozzle (error in ink flight direction, error in ink amount, and the like), error in sub scan feed, and warpage of printing paper. In particular, as described above, in a general case where a dither matrix is arranged with shifts as shown in FIG. 9, how to reduce deviation in tone on each raster line is still remaining as an unsolved problem of uncertain cause. F-7. Although the above embodiments and modifications are described in terms of an inkjet printer as an example, however, the present invention is also applicable to other printing devices such as a laser printer. For example, while the calibration of density can be reduced to practice as correction of ink amount as for an inkjet printer, it can also be reduced to practice as correction of amount of light in a laser printer. Finally, the Japanese patent application (JP-A-2006-278389 filed on Oct. 12, 2006) on which the priority claim of the present application is based is incorporated herein by reference.
|
G
|
G06
|
G06K
|
15
|
00
|
|||
11627924
|
US20070123013A1-20070531
|
CONTROLLED PROCESS AND RESULTING DEVICE
|
ACCEPTED
|
20070519
|
20070531
|
[]
|
H01L21425
|
["H01L21425"]
|
7759217
|
20070126
|
20100720
|
438
|
455000
|
77782.0
|
LEE
|
HSIEN MING
|
[{"inventor_name_last": "HENLEY", "inventor_name_first": "FRANCOIS", "inventor_city": "Aptos", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Cheung", "inventor_name_first": "Nathan", "inventor_city": "Albany", "inventor_state": "CA", "inventor_country": "US"}]
|
A technique for forming a film of material (12) from a donor substrate (10). The technique has a step of introducing energetic particles (22) through a surface of a donor substrate (10) to a selected depth (20) underneath the surface, where the particles have a relatively high concentration to define a donor substrate material (12) above the selected depth. An energy source is directed to a selected region of the donor substrate to initiate a controlled cleaving action of the substrate (10) at the selected depth (20), whereupon the cleaving action provides an expanding cleave front to free the donor material from a remaining portion of the donor substrate.
|
1-51. (canceled) 52. A process for forming a film of material from a semiconductor substrate using a chemical source, the process comprising steps of: introducing particles through a surface of a semiconductor substrate to a selected depth underneath the surface, the particles being at a concentration at the selected depth to define a material to be removed above the selected depth; applying a chemical source to increase stress at the selected depth; and providing additional energy to a selected region of the semiconductor substrate to initiate a controlled cleaving action at the selected depth in the semiconductor substrate using a propagating cleave front to free a portion of the semiconductor material to be removed from the semiconductor substrate. 53. The process of claim 52 wherein the particles are derived from a source selected from the group consisting of hydrogen gas, helium gas, water vapor, methane, hydrogen compounds, and other light atomic mass particles. 54. The process of claim 52 wherein the particles are selected from the group consisting of neutral molecules, neutral atoms, charged molecules, charged atoms, and electrons. 55. The process of claim 52 wherein the particles are energetic. 56. The process of claim 55 wherein the energetic particles have sufficient kinetic energy to penetrate through the surface to the selected depth underneath the surface. 57. The process of claim 52 wherein the providing energy sustains the controlled cleaving action to remove the semiconductor material from the substrate to provide a film of material. 58. The process of claim 52 wherein the providing energy increases a controlled stress in the semiconductor material and sustains the controlled cleaving action to remove the semiconductor material from the substrate to provide a film of material. 59. The process of claim 52 wherein the introducing forms damage selected from the group consisting of atomic bond damage, bond substitution, weakening, and breaking bonds of the semiconductor substrate at the selected depth. 60. The process of claim 59 wherein the damage creates stress in the semiconductor substrate material. 61. The process of claim 59 wherein the damage reduces an ability of the semiconductor substrate material to withstand stress without a possibility of a cleaving of the substrate material. 62. The process of claim 52 wherein the propagating cleave front comprises a plurality of cleave fronts. 63. The process of claim 52 wherein the introducing causes stress of the semiconductor material region at the selected depth by a presence of the particles at the selected depth. 64. The process of claim 52 wherein the chemical source is selected from particles, fluids, gases, or liquids. 65. The process of claim 64 wherein the chemical source causes a chemical reaction. 66. The process of claim 64 wherein the chemical source is selected from the group consisting of a flood source, a time-varying source, a spatially varying source, and a continuous source. 67. The process of claim 52 wherein the introducing is a step(s) of beam line ion implantation. 68. The process of claim 52 wherein the introducing is a step(s) of plasma immersion ion implantation. 69. The process of claim 52 further comprising a step of joining the surface of the substrate to a surface of a target substrate to form a stacked assembly. 70. The process of claim 69 wherein the joining step is provided by applying an electrostatic pressure between the substrate and the target substrate. 71. The process of claim 70 wherein the joining step is provided by using an adhesive substance between the target substrate and the substrate. 72. The process of claim 70 wherein the joining step is provided by an activated surface between the target substrate and the substrate. 73. The process of claim 70 where in the joining step is provided by an interatomic bond between the target substrate and the substrate. 74. The process of claim 70 wherein the joining step is provided by a spin-on-glass between the target substrate and the substrate. 75. The process of claim 71 wherein the joining step is provided by a polyimide between the target substrate and the substrate. 76. The process of claim 52 wherein the semiconductor substrate is made of a material selected from the group consisting of silicon, silicon carbide, group IIUV material, plastic, ceramic material, monocrystalline silicon, polycrystalline silicon, amorphous silicon, and multi-layered substrate. 77. The process of claim 52 wherein the semiconductor substrate is a silicon substrate comprising an overlying layer of dielectric material, the selected depth being underneath the dielectric material. 78. The process of claim 77 wherein the dielectric material is selected from the group consisting of an oxide material, a nitride material, or an oxide/nitride material. 79. The process of claim 52 wherein the semiconductor substrate includes an overlying layer of conductive material. 80. The process of claim 79 wherein the conductive material is selected from the group consisting of a metal, a plurality of metal layers, aluminum, tungsten, titanium, titanium nitride, polycide, polysilicon, copper, indium tin oxide, silicide, platinum, gold, silver, and amorphous silicon. 81. The process of claim 52 wherein the step of introducing provides a substantially uniform distribution of particles along a plane of the material region at the selected depth. 82. The process of claim 81 wherein the substantially uniform distribution is a uniformity of less than about 5%.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to the manufacture of substrates. More particularly, the invention provides a technique including a method and device for cleaving a substrate in the fabrication of a silicon-on-insulator substrate for semiconductor integrated circuits, for example. But it will be recognized that the invention has a wider range of applicability; it can also be applied to other substrates for multi-layered integrated circuit devices, three-dimensional packaging of integrated semiconductor devices, photonic devices, piezoelectronic devices, microelectromechanical systems (“MEMS”), sensors, actuators, solar cells, flat panel displays (e.g., LCD, AMLCD), biological and biomedical devices, and the like. Craftsmen or more properly crafts-people have been building useful articles, tools, or devices using less useful materials for numerous years. In some cases, articles are assembled by way of smaller elements or building blocks. Alternatively, less useful articles are separated into smaller pieces to improve their utility. A common example of these articles to be separated include substrate structures, such as a glass plate, a diamond, a semiconductor substrate, and others. These substrate structures are often cleaved or separated using a variety of techniques. In some cases, the substrates can be separated using a saw operation. The saw operation generally relies upon a rotating blade or tool, which cuts through the substrate material to separate the substrate material into two pieces. This technique, however, is often extremely “rough” and cannot generally be used for providing precision separations in the substrate for the manufacture of fine tools and assemblies. Additionally, the saw operation often has difficulty separating or cutting extremely hard and/or brittle materials, such as diamond or glass. Accordingly, techniques have been developed to separate these hard and/or brittle materials using cleaving approaches. In diamond cutting, for example, an intense directional thermal/mechanical impulse is directed preferentially along a crystallographic plane of a diamond material. This thermal/mechanical impulse generally causes a cleave front to propagate along major crystallographic planes, where cleaving occurs when an energy level from the thermal/mechanical impulse exceeds the fracture energy level along the chosen crystallographic plane. In glass cutting, a scribe line using a tool is often impressed in a preferred direction on the glass material, which is generally amorphous in character. The scribe line causes a higher stress area surrounding the amorphous glass material. Mechanical force is placed on each side of the scribe line, which increases stress along the scribe line until the glass material fractures, preferably along the scribe line. This fracture completes the cleaving process of the glass, which can be used in a variety of applications, including households. Although the techniques described above are satisfactory, for the most part, as applied to cutting diamonds or household glass, they have severe limitations in the fabrication of small complex structures or precision workpieces. For instance, the above techniques are often “rough” and cannot be used with great precision in fabrication of small and delicate machine tools, electronic devices, or the like. Additionally, the above techniques may be useful for separating one large plane of glass from another, but are often ineffective for splitting off, shaving, or stripping a thin film of material from a larger substrate. Furthermore, the above techniques may often cause more than one cleave front, which join along slightly different planes, which is highly undesirable for precision cutting applications. From the above, it is seen that a technique for separating a thin film of material from a substrate which is cost effective and efficient is desirable.
|
<SOH> SUMMARY OF THE INVENTION <EOH>According to the present invention, an improved technique for removing a thin film of material from a substrate using a controlled cleaving action is provided. This technique allows an initiation of a cleaving process on a substrate using a single or multiple cleave region(s) through the use of controlled energy (e.g., spatial distribution) and selected conditions to allow an initiation of a cleave front(s) and to allow it to propagate through the substrate to remove a thin film of material from the substrate. In a specific embodiment, the present invention provides a process for forming a film of material from a donor substrate using a controlled cleaving process. The process includes a step of introducing energetic particles (e.g., charged or neutral molecules, atoms, or electrons having sufficient kinetic energy) through a surface of a donor substrate to a selected depth underneath the surface, where the particles are at a relatively high concentration to define a thickness of donor substrate material (e.g., thin film of detachable material) above the selected depth. To cleave the donor substrate material, the method provides energy to a selected region of the donor substrate to initiate a controlled cleaving action in the donor substrate, whereupon the cleaving action is made using a propagating cleave front(s) to free the donor material from a remaining portion of the donor substrate. In most of the embodiments, a cleave is initiated by subjecting the material with sufficient energy to fracture the material in one region, causing a cleave front, without uncontrolled shattering or cracking. The cleave front formation energy (E c ) must often be made lower than the bulk material fracture energy (E mat ) at each region to avoid shattering or cracking the material. The directional energy impulse vector in diamond cutting or the scribe line in glass cutting are, for example, the means in which the cleave energy is reduced to allow the controlled creation and propagation of a cleave front. The cleave front is in itself a higher stress region and once created, its propagation requires a lower energy to further cleave the material from this initial region of fracture. The energy required to propagate the cleave front is called the cleave front propagation energy (E p ). The relationship can be expressed as: in-line-formulae description="In-line Formulae" end="lead"? E c =E p +[cleave front stress energy] in-line-formulae description="In-line Formulae" end="tail"? A controlled cleaving process is realized by reducing E p along a favored direction(s) above all others and limiting the available energy to below the E p of other undesired directions. In any cleave process, a better cleave surface finish occurs when the cleave process occurs through only one expanding cleave front, although multiple cleave fronts do work. Numerous benefits are achieved over pre-existing techniques using the present invention. In particular, the present invention uses controlled energy and selected conditions to preferentially cleave a thin film of material from a donor substrate which includes multi-material sandwiched films. This cleaving process selectively removes the thin film of material from the substrate while preventing a possibility of damage to the film or a remaining portion of the substrate. Accordingly, the remaining substrate portion can be re-used repeatedly for other applications. Additionally, the present invention uses a relatively low temperature during the controlled cleaving process of the thin film to reduce temperature excursions of the separated film, donor substrate, or multi-material films according to other embodiments. This lower temperature approach allows for more material and process latitude such as, for example, cleaving and bonding of materials having substantially different thermal expansion coefficients. In other embodiments, the present invention limits energy or stress in the substrate to a value below a cleave initiation energy, which generally removes a possibility of creating random cleave initiation sites or fronts. This reduces cleave damage (e.g., pits, crystalline defects, breakage, cracks, steps, voids, excessive roughness) often caused in pre-existing techniques. Moreover, the present invention reduces damage caused by higher than necessary stress or pressure effects and nucleation sites caused by the energetic particles as compared to pre-existing techniques. The present invention achieves these benefits and others in the context of known process technology. However, a further understanding of the nature and advantages of the present invention may be realized by reference to the latter portions of the specification and attached drawings.
|
CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority from the provisional patent application entitled A CONTROLLED CLEAVAGE PROCESS AND RESULTING DEVICE, filed May 12, 1997 and assigned Application No. 60/046,276, the disclosure of which is hereby incorporated in its entirety for all purposes. BACKGROUND OF THE INVENTION The present invention relates to the manufacture of substrates. More particularly, the invention provides a technique including a method and device for cleaving a substrate in the fabrication of a silicon-on-insulator substrate for semiconductor integrated circuits, for example. But it will be recognized that the invention has a wider range of applicability; it can also be applied to other substrates for multi-layered integrated circuit devices, three-dimensional packaging of integrated semiconductor devices, photonic devices, piezoelectronic devices, microelectromechanical systems (“MEMS”), sensors, actuators, solar cells, flat panel displays (e.g., LCD, AMLCD), biological and biomedical devices, and the like. Craftsmen or more properly crafts-people have been building useful articles, tools, or devices using less useful materials for numerous years. In some cases, articles are assembled by way of smaller elements or building blocks. Alternatively, less useful articles are separated into smaller pieces to improve their utility. A common example of these articles to be separated include substrate structures, such as a glass plate, a diamond, a semiconductor substrate, and others. These substrate structures are often cleaved or separated using a variety of techniques. In some cases, the substrates can be separated using a saw operation. The saw operation generally relies upon a rotating blade or tool, which cuts through the substrate material to separate the substrate material into two pieces. This technique, however, is often extremely “rough” and cannot generally be used for providing precision separations in the substrate for the manufacture of fine tools and assemblies. Additionally, the saw operation often has difficulty separating or cutting extremely hard and/or brittle materials, such as diamond or glass. Accordingly, techniques have been developed to separate these hard and/or brittle materials using cleaving approaches. In diamond cutting, for example, an intense directional thermal/mechanical impulse is directed preferentially along a crystallographic plane of a diamond material. This thermal/mechanical impulse generally causes a cleave front to propagate along major crystallographic planes, where cleaving occurs when an energy level from the thermal/mechanical impulse exceeds the fracture energy level along the chosen crystallographic plane. In glass cutting, a scribe line using a tool is often impressed in a preferred direction on the glass material, which is generally amorphous in character. The scribe line causes a higher stress area surrounding the amorphous glass material. Mechanical force is placed on each side of the scribe line, which increases stress along the scribe line until the glass material fractures, preferably along the scribe line. This fracture completes the cleaving process of the glass, which can be used in a variety of applications, including households. Although the techniques described above are satisfactory, for the most part, as applied to cutting diamonds or household glass, they have severe limitations in the fabrication of small complex structures or precision workpieces. For instance, the above techniques are often “rough” and cannot be used with great precision in fabrication of small and delicate machine tools, electronic devices, or the like. Additionally, the above techniques may be useful for separating one large plane of glass from another, but are often ineffective for splitting off, shaving, or stripping a thin film of material from a larger substrate. Furthermore, the above techniques may often cause more than one cleave front, which join along slightly different planes, which is highly undesirable for precision cutting applications. From the above, it is seen that a technique for separating a thin film of material from a substrate which is cost effective and efficient is desirable. SUMMARY OF THE INVENTION According to the present invention, an improved technique for removing a thin film of material from a substrate using a controlled cleaving action is provided. This technique allows an initiation of a cleaving process on a substrate using a single or multiple cleave region(s) through the use of controlled energy (e.g., spatial distribution) and selected conditions to allow an initiation of a cleave front(s) and to allow it to propagate through the substrate to remove a thin film of material from the substrate. In a specific embodiment, the present invention provides a process for forming a film of material from a donor substrate using a controlled cleaving process. The process includes a step of introducing energetic particles (e.g., charged or neutral molecules, atoms, or electrons having sufficient kinetic energy) through a surface of a donor substrate to a selected depth underneath the surface, where the particles are at a relatively high concentration to define a thickness of donor substrate material (e.g., thin film of detachable material) above the selected depth. To cleave the donor substrate material, the method provides energy to a selected region of the donor substrate to initiate a controlled cleaving action in the donor substrate, whereupon the cleaving action is made using a propagating cleave front(s) to free the donor material from a remaining portion of the donor substrate. In most of the embodiments, a cleave is initiated by subjecting the material with sufficient energy to fracture the material in one region, causing a cleave front, without uncontrolled shattering or cracking. The cleave front formation energy (Ec) must often be made lower than the bulk material fracture energy (Emat) at each region to avoid shattering or cracking the material. The directional energy impulse vector in diamond cutting or the scribe line in glass cutting are, for example, the means in which the cleave energy is reduced to allow the controlled creation and propagation of a cleave front. The cleave front is in itself a higher stress region and once created, its propagation requires a lower energy to further cleave the material from this initial region of fracture. The energy required to propagate the cleave front is called the cleave front propagation energy (Ep). The relationship can be expressed as: Ec=Ep+[cleave front stress energy] A controlled cleaving process is realized by reducing Ep along a favored direction(s) above all others and limiting the available energy to below the Ep of other undesired directions. In any cleave process, a better cleave surface finish occurs when the cleave process occurs through only one expanding cleave front, although multiple cleave fronts do work. Numerous benefits are achieved over pre-existing techniques using the present invention. In particular, the present invention uses controlled energy and selected conditions to preferentially cleave a thin film of material from a donor substrate which includes multi-material sandwiched films. This cleaving process selectively removes the thin film of material from the substrate while preventing a possibility of damage to the film or a remaining portion of the substrate. Accordingly, the remaining substrate portion can be re-used repeatedly for other applications. Additionally, the present invention uses a relatively low temperature during the controlled cleaving process of the thin film to reduce temperature excursions of the separated film, donor substrate, or multi-material films according to other embodiments. This lower temperature approach allows for more material and process latitude such as, for example, cleaving and bonding of materials having substantially different thermal expansion coefficients. In other embodiments, the present invention limits energy or stress in the substrate to a value below a cleave initiation energy, which generally removes a possibility of creating random cleave initiation sites or fronts. This reduces cleave damage (e.g., pits, crystalline defects, breakage, cracks, steps, voids, excessive roughness) often caused in pre-existing techniques. Moreover, the present invention reduces damage caused by higher than necessary stress or pressure effects and nucleation sites caused by the energetic particles as compared to pre-existing techniques. The present invention achieves these benefits and others in the context of known process technology. However, a further understanding of the nature and advantages of the present invention may be realized by reference to the latter portions of the specification and attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1-11 are simplified diagrams illustrating a controlled cleaving technique according to embodiments of the present invention; FIG. 12A is a simplified diagram illustrating a controlled cleaving technique using dynamic pressure embodied as a high-pressure jet of fluid or gas to separate a thin film of material from a donor wafer according to another embodiment of the present invention; FIG. 12B is a simplified diagram illustrating a controlled cleaving technique using static pressure to separate a thin film of material from a donor wafer according to another embodiment of the present invention; FIG. 13 is a simplified diagram illustrating the use of static fluid pressure to separate a thin film of material from a donor wafer; and FIGS. 14-18 are simplified cross-sectional view diagrams illustrating a method of forming a silicon-on-insulator substrate according to the present invention. DESCRIPTION OF THE SPECIFIC EMBODIMENT The present invention provides a technique for removing a thin film of material from a substrate while preventing a possibility of damage to the thin material film and/or a remaining portion of the substrate. The thin film of material is attached to or can be attached to a target substrate to form, for example, a silicon-on-insulator wafer. The thin film of material can also be used for a variety of other applications. The invention will be better understood by reference to the Figs. and the descriptions below. 1. Controlled Cleaving Techniques FIG. 1 is a simplified cross-sectional view diagram of a substrate 10 according to the present invention. The diagram is merely an illustration and should not limit the scope of the claims herein. As merely an example, substrate 10 is a silicon wafer which includes a material region 12 to be removed, which is a thin relatively uniform film derived from the substrate material. The silicon wafer 10 includes a top surface 14, a bottom surface 16, and a thickness 18. Substrate 10 also has a first side (side 1) and a second side (side 2) (which are also referenced below in the Figs.). Material region 12 also includes a thickness 20, within the thickness 18 of the silicon wafer. The present invention provides a novel technique for removing the material region 12 using the following sequence of steps. Selected energetic particles implant 22 through the top surface 14 of the silicon wafer to a selected depth 24, which defines the thickness 20 of the material region 12, termed the “thin film” of material. A variety of techniques can be used to implant the energetic particles into the silicon wafer. These techniques include ion implantation using, for example, beam line ion implantation equipment manufactured from companies such as Applied Materials, Eaton Corporation, Varian, and others. Alternatively, implantation occurs using a plasma immersion ion implantation (“PIII”) technique. Examples of plasma immersion ion implantation techniques are described in “Recent Applications of Plasma Immersion Ion Implantation,” Paul K. Chu, Chung Chan, and Nathan W. Cheung, SEMICONDUCTOR INTERNATIONAL, pp. 165-172, June 1996, and “Plasma Immersion Ion Implantation—A Fledgling Technique for Semiconductor Processing,”, P. K. Chu, S. Qin, C. Chan, N. W. Cheung, and L. A. Larson, MATERIALS SCIENCE AND ENGINEERING REPORTS: A REVIEW JOURNAL, pp. 207-280, Vol. R17, Nos. 6-7, (Nov. 30, 1996), which are both hereby incorporated by reference for all purposes. Of course, techniques used depend upon the application. Depending upon the application, smaller mass particles are generally selected to reduce a possibility of damage to the material region 12. That is, smaller mass particles easily travel through the substrate material to the selected depth without substantially damaging the material region that the particles traverse through. For example, the smaller mass particles (or energetic particles) can be almost any charged (e.g., positive or negative) and/or neutral atoms or molecules, or electrons, or the like. In a specific embodiment, the particles can be neutral and/or charged particles including ions such as ions of hydrogen and its isotopes, rare gas ions such as helium and its isotopes, and neon. The particles can also be derived from compounds such as gases, e.g., hydrogen gas, water vapor, methane, and hydrogen compounds, and other light atomic mass particles. Alternatively, the particles can be any combination of the above particles, and/or ions and/or molecular species and/or atomic species. The particles generally have sufficient kinetic energy to penetrate through the surface to the selected depth underneath the surface. Using hydrogen as the implanted species into the silicon wafer as an example, the implantation process is performed using a specific set of conditions. Implantation dose ranges from about 1015 to about 1018 atoms/cm2, and preferably the dose is greater than about 1016 atoms/cm2. Implantation energy ranges from about 1 KeV to about 1 MeV, and is generally about 50 KeV. Implantation temperature ranges from about −200 to about 600° C., and is preferably less than about 400° C. to prevent a possibility of a substantial quantity of hydrogen ions from diffusing out of the implanted silicon wafer and annealing the implanted damage and stress. The hydrogen ions can be selectively introduced into the silicon wafer to the selected depth at an accuracy of about +/−0.03 to +/−0.05 microns. Of course, the type of ion used and process conditions depend upon the application. Effectively, the implanted particles add stress or reduce fracture energy along a plane parallel to the top surface of the substrate at the selected depth. The energies depend, in part, upon the implantation species and conditions. These particles reduce a fracture energy level of the substrate at the selected depth. This allows for a controlled cleave along the implanted plane at the selected depth. Implantation can occur under conditions such that the energy state of the substrate at all internal locations is insufficient to initiate a non-reversible fracture (i.e., separation or cleaving) in the substrate material. It should be noted, however, that implantation does generally cause a certain amount of defects (e.g., micro-detects) in the substrate that can typically at least partially be repaired by subsequent heat treatment, e.g., thermal annealing or rapid thermal annealing. FIG. 2 is a simplified energy diagram 200 along a cross-section of the implanted substrate 10 according to the present invention. The diagram is merely an illustration and should not limit the scope of the claims herein. The simplified diagram includes a vertical axis 201 that represents an energy level (E) (or additional energy) to cause a cleave in the substrate. A horizontal axis 203 represents a depth or distance from the bottom of the wafer to the top of the wafer. After implanting particles into the wafer, the substrate has an average cleave energy represented as E 205, which is the amount of energy needed to cleave the wafer along various cross-sectional regions along the wafer depth. The cleave energy (Ec) is equal to the bulk material fracture energy (Emat) in non-implanted regions. At the selected depth 20, energy (Ecz) 207 is lower since the implanted particles essentially break or weaken bonds in the crystalline structure (or increase stress caused by a presence of particles also contributing to lower energy (Ecz) 207 of the substrate) to lower the amount of energy needed to cleave the substrate at the selected depth. The present invention takes advantage of the lower energy (or increased stress) at the selected depth to cleave the thin film in a controlled manner. Substrates, however, are not generally free from defects or “weak” regions across the possible cleave front or selected depth zo after the implantation process. In these cases, the cleave generally cannot be controlled, since they are subject to random variations such as bulk material non-uniformities, built-in stresses, defects, and the like. FIG. 3 is a simplified energy diagram 300 across a cleave front for the implanted substrate 10 having these defects. The diagram 300 is merely an illustration and should not limit the scope of the claims herein. The diagram has a vertical axis 301 which represents additional energy (E) and a horizontal axis 303 which represents a distance from side 1 to side 2 of the substrate, that is, the horizontal axis represents regions along the cleave front of the substrate. As shown, the cleave front has two regions 305 and 307 represented as region 1 and region 2, respectively, which have cleave energies less than the average cleave energy (Ecz) 207 (possibly due to a higher concentration of defects or the like). Accordingly, it is highly likely that the cleave process begins at one or both of the above regions, since each region has a lower cleave energy than surrounding regions. An example of a cleave process for the substrate illustrated by the above Fig. is described as follows with reference to FIG. 4. FIG. 4 is a simplified top-view diagram 400 of multiple cleave fronts 401, 403 propagating through the implanted substrate. The cleave fronts originate at “weaker” regions in the cleave plane, which specifically includes regions 1 and 2. The cleave fronts originate and propagate randomly as shown by the arrows. A limitation with the use of random propagation among multiple cleave fronts is the possibility of having different cleave fronts join along slightly different planes or the possibility of forming cracks, which is described in more detail below. FIG. 5 is a simplified cross-sectional view 500 of a film cleaved from a wafer having multiple cleave fronts at, for example, regions 1 305 and 2 307. This diagram is merely an illustration and should not limit the scope of the claims herein. As shown, the cleave from region 1 joined with the cleave from region 2 at region 3 309, which is defined along slightly different planes, may initiate a secondary cleave or crack 311 along the film. Depending upon the magnitude of the difference 313, the film may not be of sufficient quality for use in manufacture of substrates for integrated circuits or other applications. A substrate having crack 311 generally cannot be used for processing. Accordingly, it is generally undesirable to cleave a wafer using multiple fronts in a random manner. An example of a technique which may form multiple cleave fronts in a random manner is described in U.S. Pat. No. 5,374,564, which is in the name of Michel Bruel (“Bruel”), and assigned to Commissariat A l'Energie Atomique in France. Bruel generally describes a technique for cleaving an implanted wafer by global thermal treatment (i.e., thermally treating the entire plane of the implant) using thermally activated diffusion. Global thermal treatment of the substrate generally causes an initiation of multiple cleave fronts which propagate independently. In general, Bruel discloses a technique for an “uncontrollable” cleaving action by way of initiating and maintaining a cleaving action by a global thermal source, which may produce undesirable results. These undesirable results include potential problems such as an imperfect joining of cleave fronts, an excessively rough surface finish on the surface of the cleaved material since the energy level for maintaining the cleave exceeds the amount required, and many others. The present invention overcomes the formation of random cleave fronts by a controlled distribution or selective positioning of energy on the implanted substrate. FIG. 6 is a simplified cross-sectional view of an implanted substrate 10 using selective positioning of cleave energy according to the present invention. This diagram is merely an illustration, and should not limit the scope of the claims herein. The implanted wafer undergoes a step of selective energy placement or positioning or targeting which provides a controlled cleaving action of the material region 12 at the selected depth. The impulse or impulses are provided using energy sources. Examples of sources include, among others, a chemical source, a mechanical source, an electrical source, and a thermal sink or source. The chemical source can include particles, fluids, gases, or liquids. These sources can also include a chemical reaction to increase stress in the material region. The chemical source is introduced as flood, time-varying, spatially varying, or continuous. In other embodiments, a mechanical source is derived from rotational, translational, compressional, expansional, or ultrasonic energies. The mechanical source can be introduced as flood, time-varying, spatially varying, or continuous. In further embodiments, the electrical source is selected from an applied voltage or an applied electro-magnetic field, which is introduced as flood, time-varying, spatially varying, or continuous. In still further embodiments, the thermal source or sink is selected from radiation, convection, or conduction. This thermal source can be selected from, among others, a photon beam, a fluid jet, a liquid jet, a gas jet, an electro/magnetic field, an electron beam, a thermoelectric heating, a furnace, and the like. The thermal sink can be selected from a fluid jet, a liquid jet, a gas jet, a cryogenic fluid, a super-cooled liquid, a thermoelectric cooling means, an electro/magnetic field, and others. Similar to the previous embodiments, the thermal source is applied as flood, time-varying, spatially varying, or continuous. Still further, any of the above embodiments can be combined or even separated, depending upon the application. Of course, the type of source used depends upon the application. In a specific embodiment, the present invention provides a controlled-propagating cleave. The controlled-propagating cleave uses multiple successive impulses to initiate and perhaps propagate a cleaving process 700, as illustrated by FIG. 7. This diagram is merely an illustration, and should not limit the scope of the claims herein. As shown, the impulse is directed at an edge of the substrate, which propagates a cleave front toward the center of the substrate to remove the material layer from the substrate. In this embodiment, a source applies multiple pulses (i.e., pulse 1, 2, and 3) successively to the substrate. Pulse 1 701 is directed to an edge 703 of the substrate to initiate the cleave action. Pulse 2 705 is also directed at the edge 707 on one side of pulse 1 to expand the cleave front. Pulse 3 709 is directed to an opposite edge 711 of pulse 1 along the expanding cleave front to further remove the material layer from the substrate. The combination of these impulses or pulses provides a controlled cleaving action 713 of the material layer from the substrate. FIG. 8 is a simplified illustration of selected energies 800 from the pulses in the preceding embodiment for the controlled-propagating cleave. This diagram is merely an illustration, and should not limit the scope of the claims herein. As shown, the pulse 1 has an energy level which exceeds average cleaving energy (E), which is the necessary energy for initiating the cleaving action. Pulses 2 and 3 are made using lower energy levels along the cleave front to maintain or sustain the cleaving action. In a specific embodiment, the pulse is a laser pulse where an impinging beam heats a selected region of the substrate through a pulse and a thermal pulse gradient causes supplemental stresses which together exceed cleave formation or propagation energies, which create a single cleave front. In preferred embodiments, the impinging beam heats and causes a thermal pulse gradient simultaneously, which exceeds cleave energy formation or propagation energies. More preferably, the impinging beam cools and causes a thermal pulse gradient simultaneously, which exceeds cleave energy formation or propagation energies. Optionally, a built-in energy state of the substrate or stress can be globally raised toward the energy level necessary to initiate the cleaving action, but not enough to initiate the cleaving action before directing the multiple successive impulses to the substrate according to the present invention. The global energy state of the substrate can be raised or lowered using a variety of sources such as chemical, mechanical, thermal (sink or source), or electrical, alone or in combination. The chemical source can include a variety such as particles, fluids, gases, or liquids. These sources can also include chemical reaction to increase stress in the material region. The chemical source is introduced as flood, time-varying, spatially varying, or continuous. In other embodiments, a mechanical source is derived from rotational, translational, compressional, expansional, or ultrasonic energies. The mechanical source can be introduced as flood, time-varying, spatially varying, or continuous. In further embodiments, the electrical source is selected from an applied voltage or an applied electro-magnetic field, which is introduced as flood, time-varying, spatially varying, or continuous. In still further embodiments, the thermal source or sink is selected from radiation, convection, or conduction. This thermal source can be selected from, among others, a photon beam, a fluid jet, a liquid jet, a gas jet, an electro/magnetic field, an electron beam, a thermoelectric heating, and a furnace. The thermal sink can be selected from a fluid jet, a liquid jet, a gas jet, a cryogenic fluid, a super-cooled liquid, a thermoelectric cooling means, an electro/magnetic field, and others. Similar to the previous embodiments, the thermal source is applied as flood, time-varying, spatially varying, or continuous. Still further, any of the above embodiments can be combined or even separated, depending upon the application. Of course, the type of source used also depends upon the application. As noted, the global source increases a level of energy or stress in the material region without initiating a cleaving action in the material region before providing energy to initiate the controlled cleaving action. In a specific embodiment, an energy source elevates an energy level of the substrate cleave plane above its cleave front propagation energy but is insufficient to cause self-initiation of a cleave front. In particular, a thermal energy source or sink in the form of heat or lack of heat (e.g., cooling source) can be applied globally to the substrate to increase the energy state or stress level of the substrate without initiating a cleave front. Alternatively, the energy source can be electrical, chemical, or mechanical. A directed energy source provides an application of energy to a selected region of the substrate material to initiate a cleave front which self-propagates through the implanted region of the substrate until the thin film of material is removed. A variety of techniques can be used to initiate the cleave action. These techniques are described by way of the Figs. below. FIG. 9 is a simplified illustration of an energy state 900 for a controlled cleaving action using a single controlled source according to an aspect of the present invention. This diagram is merely an illustration, and should not limit the scope of the claims herein. In this embodiment, the energy level or state of the substrate is raised using a global energy source above the cleave front propagation energy state, but is lower than the energy state necessary to initiate the cleave front. To initiate the cleave front, an energy source such as a laser directs a beam in the form of a pulse at an edge of the substrate to initiate the cleaving action. Alternatively, the energy source can be a cooling fluid (e.g., liquid, gas) that directs a cooling medium in the form of a pulse at an edge of the substrate to initiate the cleaving action. The global energy source maintains the cleaving action which generally requires a lower energy level than the initiation energy. An alternative aspect of the invention is illustrated by FIGS. 10 and 11. FIG. 10 is a simplified illustration of an implanted substrate 1000 undergoing rotational forces 1001, 1003. This diagram is merely an illustration, and should not limit the scope of the claims herein. As shown, the substrate includes a top surface 1005, a bottom surface 1007, and an implanted region 1009 at a selected depth. An energy source increases a global energy level of the substrate using a light beam or heat source to a level above the cleave front propagation energy state, but lower than the energy state necessary to initiate the cleave front. The substrate undergoes a rotational force turning clockwise 1001 on top surface and a rotational force turning counter-clockwise 1003 on the bottom surface which creates stress at the implanted region 1009 to initiate a cleave front. Alternatively, the top surface undergoes a counter-clockwise rotational force and the bottom surface undergoes a clockwise rotational force. Of course, the direction of the force generally does not matter in this embodiment. FIG. 11 is a simplified diagram of an energy state 1100 for the controlled cleaving action using the rotational force according to the present invention. This diagram is merely an illustration, and should not limit the scope of the claims herein. As previously noted, the energy level or state of the substrate is raised using a global energy source (e.g., thermal, beam) above the cleave front propagation energy state, but is lower than the energy state necessary to initiate the cleave front. To initiate the cleave front, a mechanical energy means such as rotational force applied to the implanted region initiates the cleave front. In particular, rotational force applied to the implanted region of the substrates creates zero stress at the center of the substrate and greatest at the periphery, essentially being proportional to the radius. In this example, the central initiating pulse causes a radially expanding cleave front to cleave the substrate. The removed material region provides a thin film of silicon material for processing. The silicon material possesses limited surface roughness and desired planarity characteristics for use in a silicon-on-insulator substrate. In certain embodiments, the surface roughness of the detached film has features that are less than about 60 nm, or less than about 40 nm, or less than about 20 nm. Accordingly, the present invention provides thin silicon films which can be smoother and more uniform than pre-existing techniques. In a specific embodiment, the energy source can be a fluid jet that is pressurized (e.g., compressional) according to an embodiment of the present invention. FIG. 12A shows a simplified cross-sectional view diagram of a fluid jet from a fluid nozzle 608 used to perform the controlled cleaving process according to an embodiment of the present invention. The fluid jet 607 (or liquid jet or gas jet) impinges on an edge region of substrate 10 to initiate the controlled cleaving process. The fluid jet from a compressed or pressurized fluid source is directed to a region at the selected depth 603 to cleave a thickness of material region 12 from substrate 10 using force, e.g., mechanical, chemical, thermal. As shown, the fluid jet separates substrate 10 into two regions, including region 609 and region 611 that separate from each other at selected depth 603. The fluid jet can also be adjusted to initiate and maintain the controlled cleaving process to separate material 12 from substrate 10. Depending upon the application, the fluid jet can be adjusted in direction, location, and magnitude to achieve the desired controlled cleaving process. The fluid jet can be a liquid jet or a gas jet or a combination of liquid and gas. The fluid jet can separate a thin film from the substrate at ambient (i.e. room) temperature, but the substrate and/or jet can also be heated or cooled to facilitate the separation process. In a preferred embodiment, the energy source can be a compressional source such as, for example, compressed fluid that is static. FIG. 12B shows a simplified cross-sectional view diagram of a compressed fluid source 607 according to an embodiment of the present invention. The compressed fluid source 607 (e.g., pressurized liquid, pressurized gas) is applied to a sealed chamber 621, which surrounds a periphery or edge of the substrate 10. As shown, the chamber is enclosed by device 623, which is sealed by, for example, O-rings 625 or the like, and which surrounds the outer edge of the substrate. The chamber has a pressure maintained at PC that is applied to the edge region of substrate 10 to initiate the controlled cleaving process at the selected depth of implanted material. The outer surface or face of the substrate is maintained at pressure PA which can be ambient pressure e.g., 1 atmosphere or less. A pressure differential exists between the pressure in the chamber, which is higher, and the ambient pressure. The pressure difference applies force to the implanted region at the selected depth 603. The implanted region at the selected depth is structurally weaker than surrounding regions, including any bonded regions. Force is applied via the pressure differential until the controlled cleaving process is initiated. The controlled cleaving process separates the thickness of material 609 from substrate material 611 to split the thickness of material from the substrate material at the selected depth. Additionally, pressure PC forces material region 12 to separate by a “prying action” from substrate material 611. During the cleaving process, the pressure in the chamber can also be adjusted to initiate and maintain the controlled cleaving process to separate material 12 from substrate 10. Depending upon the application, the pressure can be adjusted in magnitude to achieve the desired controlled cleaving process. The fluid pressure can be derived from a liquid or a gas or a combination of liquid and gas. Optionally, a mechanical force, as from a pin or blade, may be applied to the edge of the implanted region to initiate the cleaving process, which typically reduces the maximum pressure differential required between the chamber and the ambient. In a preferred embodiment, the present invention is practiced at temperatures that are lower than those used by pre-existing techniques. In particular, the present invention does not require increasing the entire substrate temperature to initiate and sustain the cleaving action as pre-existing techniques. In some embodiments for silicon wafers and hydrogen implants, substrate temperature does not exceed about 400° C. during the cleaving process. Alternatively, substrate temperature does not exceed about 350° C. during the cleaving process. Alternatively, substrate temperature is kept substantially below implanting temperatures via a thermal sink, e.g., cooling fluid, cryogenic fluid. Accordingly, the present invention reduces a possibility of unnecessary damage from an excessive release of energy from random cleave fronts, which generally improves surface quality of a detached film(s) and/or the substrate(s). Accordingly, the present invention provides resulting films on substrates at higher overall yields and quality. The above embodiments are described in terms of cleaving a thin film of material from a substrate. The substrate, however, can be disposed on a workpiece such as a stiffener or the like before the controlled cleaving process. The workpiece joins to a top surface or implanted surface of the substrate to provide structural support to the thin film of material during controlled cleaving processes. The workpiece can be joined to the substrate using a variety of bonding or joining techniques, e.g., electro-statics, adhesives, interatomic. Some of these bonding techniques are described herein. The workpiece can be made of a dielectric material (e.g., quartz, glass, sapphire, silicon nitride, silicon dioxide), a conductive material (silicon, silicon carbide, polysilicon, group III/V materials, metal), and plastics (e.g., polyimide-based materials). Of course, the type of workpiece used will depend upon the application. Alternatively, the substrate having the film to be detached can be temporarily disposed on a transfer substrate such as a stiffener or the like before the controlled cleaving process. The transfer substrate joins to a top surface or implanted surface of the substrate having the film to provide structural support to the thin film of material during controlled cleaving processes. The transfer substrate can be temporarily joined to the substrate having the film using a variety of bonding or joining techniques, e.g., electro-statics, adhesives, interatomic. Some of these bonding techniques are described herein. The transfer substrate can be made of a dielectric material (e.g., quartz, glass, sapphire, silicon nitride, silicon dioxide), a conductive material (silicon, silicon carbide, polysilicon, group III/V materials, metal), and plastics (e.g., polyimide-based materials). Of course, the type of transfer substrate used will depend upon the application. Additionally, the transfer substrate can be used to remove the thin film of material from the cleaved substrate after the controlled cleaving process. 2. Silicon-On-Insulator Process A process for fabricating a silicon-on-insulator substrate according to the present invention may be briefly outlined as follows: (1) Provide a donor silicon wafer (which may be coated with a dielectric material); (2) Introduce particles into the silicon wafer to a selected depth to define a thickness of silicon film; (3) Provide a target substrate material (which may be coated with a dielectric material); (4) Bond the donor silicon wafer to the target substrate material by joining the implanted face to the target substrate material; (5) Increase global stress (or energy) of implanted region at selected depth without initiating a cleaving action (optional); (6) Provide stress (or energy) to a selected region of the bonded substrates to initiate a controlled cleaving action at the selected depth; (7) Provide additional energy to the bonded substrates to sustain the controlled cleaving action to free the thickness of silicon film from the silicon wafer (optional); (8) Complete bonding of donor silicon wafer to the target substrate; and (9) Polish a surface of the thickness of silicon film. The above sequence of steps provides a step of initiating a controlled cleaving action using an energy applied to a selected region(s) of a multi-layered substrate structure to form a cleave front(s) according to the present invention. This initiation step begins a cleaving process in a controlled manner by limiting the amount of energy applied to the substrate. Further propagation of the cleaving action can occur by providing additional energy to selected regions of the substrate to sustain the cleaving action, or using the energy from the initiation step to provide for further propagation of the cleaving action. This sequence of steps is merely an example and should not limit the scope of the claims defined herein. Further details with regard to the above sequence of steps are described in below in references to the Figs. FIGS. 14-19 are simplified cross-sectional view diagrams of substrates undergoing a fabrication process for a silicon-on-insulator wafer according to the present invention. The process begins by providing a semiconductor substrate similar to the silicon wafer 2100, as shown by FIG. 14. Substrate or donor includes a material region 2101 to be removed, which is a thin relatively uniform film derived from the substrate material. The silicon wafer includes a top surface 2103, a bottom surface 2105, and a thickness 2107. Material region also includes a thickness (z0), within the thickness 2107 of the silicon wafer. Optionally, a dielectric layer 2102 (e.g., silicon nitride, silicon oxide, silicon oxynitride) overlies the top surface of the substrate. The present process provides a novel technique for removing the material region 2101 using the following sequence of steps for the fabrication of a silicon-on-insulator wafer. Selected energetic particles 2109 implant through the top surface of the silicon wafer to a selected depth, which defines the thickness of the material region, termed the thin film of material. As shown, the particles have a desired concentration 2111 at the selected depth (z0). A variety of techniques can be used to implant the energetic particles into the silicon wafer. These techniques include ion implantation using, for example, beam line ion implantation equipment manufactured from companies such as Applied Materials, Eaton Corporation, Varian, and others. Alternatively, implantation occurs using a plasma immersion ion implantation (“PIII”) technique. Of course, techniques used depend upon the application. Depending upon the application, smaller mass particles are generally selected to reduce a possibility of damage to the material region. That is, smaller mass particles easily travel through the substrate material to the selected depth without substantially damaging the material region that the particles traversed through. For example, the smaller mass particles (or energetic particles) can be almost any charged (e.g., positive or negative) and/or neutral atoms or molecules, or electrons, or the like. In a specific embodiment, the particles can be neutral and/or charged particles including ions of hydrogen and its isotopes, rare gas ions such as helium and its isotopes, and neon. The particles can also be derived from compounds such as gases, e.g., hydrogen gas, water vapor, methane, and other hydrogen compounds, and other light atomic mass particles. Alternatively, the particles can be any combination of the above particles, and/or ions and/or molecular species and/or atomic species. The process uses a step of joining the implanted silicon wafer to a workpiece 2200 or target wafer, as illustrated in FIG. 15. The workpiece may also be a variety of other types of substrates such as those made of a dielectric material (e.g., quartz, glass, silicon nitride, silicon dioxide), a conductive material (silicon, polysilicon, group III/V materials, metal), and plastics (e.g., polyimide-based materials). In the present example, however, the workpiece is a silicon wafer. In a specific embodiment, the silicon wafers are joined or fused together using a low temperature thermal step. The low temperature thermal process generally ensures that the implanted particles do not place excessive stress on the material region, which can produce an uncontrolled cleave action. In one aspect, the low temperature bonding process occurs by a self-bonding process. In particular, one wafer is stripped to remove oxidation therefrom (or one wafer is not oxidized). A cleaning solution treats the surface of the wafer to form O—H bonds on the wafer surface. An example of a solution used to clean the wafer is a mixture of H2O2—H2SO4. A dryer dries the wafer surfaces to remove any residual liquids or particles from the wafer surfaces. Self-bonding occurs by placing a face of the cleaned wafer against the face of an oxidized wafer. Alternatively, a self-bonding process occurs by activating one of the wafer surfaces to be bonded by plasma cleaning. In particular, plasma cleaning activates the wafer surface using a plasma derived from gases such as argon, ammonia, neon, water vapor, and oxygen. The activated wafer surface 2203 is placed against a face of the other wafer, which has a coat of oxidation 2205 thereon. The wafers are in a sandwiched structure having exposed wafer faces. A selected amount of pressure is placed on each exposed face of the wafers to self-bond one wafer to the other. Alternatively, an adhesive disposed on the wafer surfaces is used to bond one wafer onto the other. The adhesive includes an epoxy, polyimide-type materials, and the like. Spin-on-glass layers can be used to bond one wafer surface onto the face of another. These spin-on-glass (“SOG”) materials include, among others, siloxanes or silicates, which are often mixed with alcohol-based solvents or the like. SOG can be a desirable material because of the low temperatures (e.g., 150 to 250° C.) often needed to cure the SOG after it is applied to surfaces of the wafers. Alternatively, a variety of other low temperature techniques can be used to join the donor wafer to the target wafer. For instance, an electro-static bonding technique can be used to join the two wafers together. In particular, one or both wafer surface(s) is charged to attract to the other wafer surface. Additionally, the donor wafer can be fused to the target wafer using a variety of commonly known techniques. Of course, the technique used depends upon the application. After bonding the wafers into a sandwiched structure 2300, as shown in FIG. 16, the method includes a controlled cleaving action to remove the substrate material to provide a thin film of substrate material 2101 overlying an insulator 2305 the target silicon wafer 2201. The controlled-cleaving occurs by way of selective energy placement or positioning or targeting 2301, 2303 of energy sources onto the donor and/or target wafers. For instance, an energy impulse(s) can be used to initiate the cleaving action. The impulse (or impulses) is provided using an energy source which include, among others, a mechanical source, a chemical source, a thermal sink or source, and an electrical source. The controlled cleaving action is initiated by way of any of the previously noted techniques and others and is illustrated by way of FIG. 16. For instance, a process for initiating the controlled cleaving action uses a step of providing energy 2301, 2303 to a selected region of the substrate to initiate a controlled cleaving action at the selected depth (z0) in the substrate, whereupon the cleaving action is made using a propagating cleave front to free a portion of the substrate material to be removed from the substrate. In a specific embodiment, the method uses a single impulse to begin the cleaving action, as previously noted. Alternatively, the method uses an initiation impulse, which is followed by another impulse or successive impulses to selected regions of the substrate. Alternatively, the method provides an impulse to initiate a cleaving action which is sustained by a scanned energy along the substrate. Alternatively, energy can be scanned across selected regions of the substrate to initiate and/or sustain the controlled cleaving action. Optionally, an energy or stress of the substrate material is increased toward an energy level necessary to initiate the cleaving action, but not enough to initiate the cleaving action before directing an impulse or multiple successive impulses to the substrate according to the present invention. The global energy state of the substrate can be raised or lowered using a variety of sources such as chemical, mechanical, thermal (sink or source), or electrical, alone or in combination. The chemical source can include particles, fluids, gases, or liquids. These sources can also include chemical reaction to increase stress in the material region. The chemical source is introduced as flood, time-varying, spatially varying, or continuous. In other embodiments, a mechanical source is derived from rotational, translational, compressional, expansional, or ultrasonic energies. The mechanical source can be introduced as flood, time-varying, spatially varying, or continuous. In further embodiments, the electrical source is selected from an applied voltage or an applied electro-magnetic field, which is introduced as flood, time-varying, spatially varying, or continuous. In still further embodiments, the thermal source or sink is selected from radiation, convection, or conduction. This thermal source can be selected from, among others, a photon beam, a fluid jet, a liquid jet, a gas jet, an electro/magnetic field, an electron beam, a thermoelectric heating, and a furnace. The thermal sink can be selected from a fluid jet, a liquid jet, a gas jet, a cryogenic fluid, a super-cooled liquid, a thermoelectric cooling means, an electro/magnetic field, and others. Similar to the previous embodiments, the thermal source is applied as flood, time-varying, spatially varying, or continuous. Still further, any of the above embodiments can be combined or even separated, depending upon the application. Of course, the type of source used depends upon the application. As noted, the global source increases a level of energy or stress in the material region without initiating a cleaving action in the material region before providing energy to initiate the controlled cleaving action. In a preferred embodiment, the method maintains a temperature which is below a temperature of introducing the particles into the substrate. In some embodiments, the substrate temperature is maintained between −200 and 450° C. during the step of introducing energy to initiate propagation of the cleaving action. Substrate temperature can also be maintained at a temperature below 400° C. or below 350° C. In preferred embodiments, the method uses a thermal sink to initiate and maintain the cleaving action, which occurs at conditions significantly below room temperature. A final bonding step occurs between the target wafer and thin film of material region according to some embodiments, as illustrated by FIG. 17. In one embodiment, one silicon wafer has an overlying layer of silicon dioxide, which is thermally grown overlying the face before cleaning the thin film of material, as shown in FIG. 15. The silicon dioxide can also be formed using a variety of other techniques, e.g., chemical vapor deposition. The silicon dioxide between the wafer surfaces fuses together thermally in this process. In some embodiments, the oxidized silicon surface from either the target wafer or the thin film of material region (from the donor wafer) are further pressed together and are subjected to an oxidizing ambient 2401. The oxidizing ambient can be in a diffusion furnace for steam oxidation, hydrogen oxidation, or the like. A combination of the pressure and the oxidizing ambient fuses the thin film of silicon material 2101 to the target silicon wafer 2201 together at the oxide surface or interface 2305. These embodiments often require high temperatures (e.g., 700° C.). Alternatively, the two silicon surfaces are further pressed together and subjected to an applied voltage between the two wafers. The applied voltage raises temperature of the wafers to induce a bonding between the wafers. This technique limits the amount of crystal defects introduced into the silicon wafers during the bonding process, since substantially no significant mechanical force is needed to initiate the bonding action between the wafers. Of course, the technique used depends upon the application. After bonding the wafers, silicon-on-insulator has a target substrate with an overlying film of silicon material and a sandwiched oxide layer between the target substrate and the silicon film, as also illustrated in FIG. 15. The detached surface of the film of silicon material is often rough 2404 and needs finishing. Finishing occurs using a combination of grinding and/or polishing techniques. In some embodiments, the detached surface undergoes a step of grinding using, for examples, techniques such as rotating an abrasive material overlying the detached surface to remove any imperfections or surface roughness therefrom. A machine such as a “back grinder” made by a company called Disco may provide this technique. Alternatively, chemical mechanical polishing or planarization (“CMP”) techniques finish the detached surface of the film, as illustrated by FIG. 18. In CMP, a slurry mixture is applied directly to a polishing surface 2501 which is attached to a rotating platen 2503. This slurry mixture can be transferred to the polishing surface by way of an orifice, which is coupled to a slurry source. The slurry is often a solution containing an abrasive and an oxidizer, e.g., H2O2, KIO3, ferric nitrate. The abrasive is often a borosilicate glass, titanium dioxide, titanium nitride, aluminum oxide, aluminum trioxide, iron nitrate, cerium oxide, silicon dioxide (colloidal silica), silicon nitride, silicon carbide, graphite, diamond, and any mixtures thereof. This abrasive is mixed in a solution of deionized water and oxidizer or the like. Preferably, the solution is acidic. This acid solution generally interacts with the silicon material from the wafer during the polishing process. The polishing process preferably uses a poly-urethane polishing pad. An example of this polishing pad is one made by Rodel and sold under the trade name of IC-1000. The polishing pad is rotated at a selected speed. A carrier head which picks up the target wafer having the film applies a selected amount of pressure on the backside of the target wafer such that a selected force is applied to the film. The polishing process removes about a selected amount of film material, which provides a relatively smooth film surface 2601 for subsequent processing, as illustrated by FIG. 18. In certain embodiments, a thin film of oxide 2406 overlies the film of material overlying the target wafer, as illustrated in FIG. 17. The oxide layer forms during the thermal annealing step, which is described above for permanently bonding the film of material to the target wafer. In these embodiments, the finishing process is selectively adjusted to first remove oxide and the film is subsequently polished to complete the process. Of course, the sequence of steps depends upon the particular application. Although the above description is in terms of a silicon wafer, other substrates may also be used. For example, the substrate can be almost any monocrystalline, polycrystalline, or even amorphous type substrate. Additionally, the substrate can be made of III/V materials such as gallium arsenide, gallium nitride (GaN), and others. The multi-layered substrate can also be used according to the present invention. The multi-layered substrate includes a silicon-on-insulator substrate, a variety of sandwiched layers on a semiconductor substrate, and numerous other types of substrates. Additionally, the embodiments above were generally in terms of providing a pulse of energy to initiate a controlled cleaving action. The pulse can be replaced by energy that is scanned across a selected region of the substrate to initiate the controlled cleaving action. Energy can also be scanned across selected regions of the substrate to sustain or maintain the controlled cleaving action. One of ordinary skill in the art would easily recognize a variety of alternatives, modifications, and variations, which can be used according to the present invention. While the above is a full description of the specific embodiments, various modifications, alternative constructions and equivalents may be used. Therefore, the above description and illustrations should not be taken as limiting the scope of the present invention which is defined by the appended claims.
|
H
|
H01
|
H01L
|
214
|
25
|
|||
11708350
|
US20070149248A1-20070628
|
Radio modem terminal for mobile communication
|
ACCEPTED
|
20070613
|
20070628
|
[]
|
H04B138
|
["H04B138", "H04M100"]
|
7610068
|
20070221
|
20091027
|
455
|
575300
|
68275.0
|
NGUYEN
|
TU
|
[{"inventor_name_last": "Mok", "inventor_name_first": "Jin-Young", "inventor_city": "Bucheon", "inventor_state": "", "inventor_country": "KR"}]
|
Disclosed is a radio modem terminal for mobile communication, comprising a main body having a functional unit for voice communication; a power supply unit hinged at one side of the main body; and a display unit disposed between the power supply unit and the main body, and also hinged with respect to the power supply unit and the main body to form a foldable type mobile communication device. When the radio modem terminal is not connected to a notebook computer, it can be used as a mobile communication terminal, using a power supply unit as its primary power source. However, if the radio modem terminal is connected to the notebook computer, it functions as the PC card, and uses power from the notebook computer as its primary source of power. Accordingly, the radio modem terminal is conveniently transported and used.
|
1. A mobile communication terminal, comprising: a first body; and a second body rotatably coupled to the first body, wherein at least one of the first body or the second body has a functional unit which provides at least one of data or voice communication capability; and wherein at least one of the first body or the second body is configured to be inserted into a personal computer. 2. The terminal of claim 1, wherein the first body includes a power supply unit. 3. The terminal of claim 2, wherein the second body is a PC card. 4. The terminal of claim 3, further comprising a third body, wherein the third body comprises a display rotatably connected to at least one of the first body or the second body. 5. The terminal of claim 3, further comprising a hinge which rotatably couples the first, second and third bodies so as to form a foldable mobile phone. 6. The terminal of claim 1, wherein at least one of the first body or the second body comprises a connector provided at an end thereof for connection to a personal computer. 7. The terminal of claim 1, wherein an operation mode of the mobile communication terminal is based on a connection between the mobile communication terminal and a personal computer. 8. The terminal of claim 7, wherein the first body includes a battery, and wherein the operation mode comprises: a first operation mode if the mobile communication terminal is inserted into a personal computer, wherein the mobile communication terminal is configured to provide at least one of voice or data communication capability to the personal computer in the first operation mode and/or to charge the battery of the first body; and a second operation mode if the mobile communication terminal is not inserted into a personal computer, wherein the mobile communication terminal uses the battery for power to allow only wireless communication. 9. The terminal of claim 1, wherein at least one of the first or second body includes function keys. 10. The terminal of claim 1, wherein the second body is configured to be inserted into a personal computer. 11. A computer system, comprising: a display; a housing configured to be connected to the display, to receive input from an input device, and to process information based on the input received from the input device; a phone configured for wireless communication, wherein the housing has a recess configured to receive the phone, and wherein a battery of the phone is charged when the phone is inserted into the recess of the housing by an electrical connection. 12. The system of claim 11, wherein the phone receives power from a first power supply housed in the housing when the phone is inserted into the recess in the housing and electrically coupled thereto by a connector. 13. The system of claim 12, wherein the phone comprises a switch which varies a connection path between the connector and a second power supply provided in the phone based on a connection state of the phone and the recess in the housing. 14. The system of claim 13, wherein the first power supply supplies power to the phone through the connector, and to at least one other sub-system of the computer system, and wherein a charging unit housed in the housing charges the second power supply provided in the phone through the connector. 15. The system of claim 11, wherein the phone comprises: a first body; a second body rotatably coupled to the first body, wherein the second body has a functional unit; and a third body rotatably coupled to the first and second bodies. 16. The system of claim 15, wherein the functional unit of the second body provides at least one of data or voice communication capability. 17. The system of claim 15, wherein the first body comprises power supply, the second body comprises a PC card, and the third body comprises a display, and wherein the first, second and third bodies are coupled to form a foldable type mobile communication device. 18. The system of claim 17, wherein the second body comprises a connector provided at one end thereof for insertion into the recess in the housing computer. 19. The system of claim 15, wherein at least one of the first, second or third body is configured to be inserted into the recess.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to mobile communication and, more particularly, to a radio modem terminal for mobile. 2. Background of the Related Art In general, a mobile communication terminal is a device allowing users to communicate with anyone, anywhere, at any time, and due to their convenience, use of mobile communication terminals is now wide spread and a number of diverse applications have been developed for their use. One such application is data communication. That is, by connecting a data port of the mobile communication terminal to a modem port of a notebook computer, access to various data communication and Internet services are made available to the user. The notebook computer has a variety of peripheral devices, such as an expansion memory, a data communication modem, LAN, or the like, which are connected to the notebook computer through a PCMCIA (Personal Computer Memory Card International Association) card or a PC card. The construction of the PCMCIA card or the PC card is based on standards established by a PCMCIA industrial group organized in 1989 to promote standards for memory and input/output integrated circuits. The 1993 PCMCIA 2.1 standards dictate a card size of 54 mm in width by 85.6 mm in length, and a 68 pin connector. The PC card can be classified into three types, depending on its thickness: TYPE 1 is mainly used for external memory expansion, and has a thickness of 3.3 mm; TYPE 2 is commonly used as a modem, LAN, a SCSI, or a sound card, and has a thickness of 5.0 mm; TYPE 3 is commonly used as an ATA (Advanced Technology Attachment) hard disk drive, and has a thickness of 10.5 mm. FIG. 1 illustrates how a notebook computer is connected to a communication network in accordance with the conventional art, which includes: a mobile communication terminal 10 with access to a mobile communication service while being transported; a notebook computer 20 implementing radio communication through the mobile communication terminal 10 ; and a connecting unit 30 connecting a data port installed in the mobile communication terminal 10 and the notebook computer 20 to enable data communication therebetween. The mobile communication terminal 10 is capable of receiving multimedia service as well as voice communication service and character information while being transported. In general, the mobile communication terminal includes a data port for data communication, through which the mobile communication terminal 10 can function as a speaker phone, update an operating program, and transmit and/or receive data. The notebook computer 20 is a portable personal computer, in which various kinds of modems can be built therein or attached thereto for data communication with an external device. The connecting unit 30 is a cable connecting the data port of the mobile communication terminal 10 and a modem of the notebook computer 20 , through which the mobile communication terminal 10 and the notebook computer 20 can conduct data communication with another computer or data unit, or conduct an Internet search using a mobile communication network. The conventional notebook computer, however, has a problem in that, since it is connected to the mobile communication terminal by a separate connecting unit, the connecting unit and the mobile phone must be separately fabricated, purchased, installed/uninstalled, and transported. Korean Patent Laid-Open Publication No. 2001-0082432 (dated Aug. 30, 2001) seeks a solution to this problem by inserting a PC card having a radio frequency unit, a CDMA processor, a memory, and an interface unit into a mobile communication terminal or into a notebook computer. More specifically, the PC card is inserted into an outer case of the mobile communication terminal for use as a mobile phone, whereas insertion of the PC card into the notebook computer enables radio data communication. Then, if a user wants to access the Internet with the notebook computer, he/she may withdraw the PC card from the mobile communication terminal and insert it into the corresponding notebook computer. The notebook computer automatically senses insertion of the PC card, and the user can then access the Internet through the notebook computer. However, because the PCMCIA TYPE 2 card is 54 mm wide by 85.6 mm long by 5 mm thick, based on the pertinent industrial standards, a problem arises in that it is difficult to mount the radio frequency unit, the CDMA processor, the memory, the interface unit, and other components on the face of the PC card. Additionally, the PC card does not function by itself, and needs a dedicated terminal case for its use, causing inconvenience in that the dedicated terminal case must also be transported. The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
|
<SOH> SUMMARY OF THE INVENTION <EOH>An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter. Therefore, an object of the present invention is to provide a radio modem terminal for mobile communication which can use an easily foldable display unit. An object of the present invention is to provide a radio modem terminal for mobile communication which can use an easily foldable power supply unit. An object of the invention is to provide a radio modem terminal for mobile communication which can use includes a PC card having a function of a mobile phone. An object of the present invention is to provide a radio modem terminal for mobile communication that can be mounted at a notebook computer by having in a PC card a switch for selecting charging/discharging of a power supply unit. To achieve at least the above objects in whole or in parts, there is provided a radio modem terminal for a mobile communication including: a main body having a functional unit for voice communication; a power supply unit hinged at one side of the main body forming a foldable type device; and a display unit hinged at one side of the main body and positioned between the power supply unit and the main body. To achieve at least these advantages in whole or in parts, there is further provided a radio modem terminal for a mobile communication including: an RF unit for processing an RF input signal; a user interface for interfacing a signal transmitted to and received from a display unit; a memory unit storing various data for operating a radio modem terminal for a mobile communication; an audio interface unit for processing a voice signal; a PCMCIA interface unit for interfacing a signal transmitted and received through the user interface unit on the basis of the PCMCIA standard; a controller for monitoring a signal transmitted and received between functional units and controlling a corresponding operation; and a connector for transmitting to and receiving from a notebook computer by being connected thereto. The present invention can be achieved in whole or in part by a radio modem terminal for mobile communication, including, a main body comprising a functional unit configured to provide voice communication capability, a power supply unit, wherein one side of the power supply unit is configured to be rotatably connected to one side of the main body, and a display unit, wherein one side of the display unit is configured to be rotatably connected to the one side of the main body, and wherein the display unit is positioned between the power supply unit and the main body. The present invention can be further achieved in whole or in part by a radio modem terminal for a mobile communication, including, an RF unit configured to process an RF input signal, a user interface configured to interface a signal transmitted to and received from a display unit, a memory unit configured to store operating data, an audio interface unit configured to process a voice signal, a PCMCIA interface unit configured to interface a signal transmitted and received through the user interface unit based on the PCMCIA standard, a controller configured to monitor a signal transmitted and received between functional units of the radio modem terminal and to control a corresponding operation, and a connector configured to connect the radio modem terminal to a notebook computer, wherein the connector is further configured to transmit a plurality of signals to and receive a plurality of signals from the notebook computer when they are connected. The present invention can be further achieved in whole or in part by a radio modem terminal for mobile communication, including, a main body, comprising a PC card, a power supply unit rotatably connected to the main body, and a display unit rotatably connected to the main body and the power supply unit. Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to mobile communication and, more particularly, to a radio modem terminal for mobile. 2. Background of the Related Art In general, a mobile communication terminal is a device allowing users to communicate with anyone, anywhere, at any time, and due to their convenience, use of mobile communication terminals is now wide spread and a number of diverse applications have been developed for their use. One such application is data communication. That is, by connecting a data port of the mobile communication terminal to a modem port of a notebook computer, access to various data communication and Internet services are made available to the user. The notebook computer has a variety of peripheral devices, such as an expansion memory, a data communication modem, LAN, or the like, which are connected to the notebook computer through a PCMCIA (Personal Computer Memory Card International Association) card or a PC card. The construction of the PCMCIA card or the PC card is based on standards established by a PCMCIA industrial group organized in 1989 to promote standards for memory and input/output integrated circuits. The 1993 PCMCIA 2.1 standards dictate a card size of 54 mm in width by 85.6 mm in length, and a 68 pin connector. The PC card can be classified into three types, depending on its thickness: TYPE 1 is mainly used for external memory expansion, and has a thickness of 3.3 mm; TYPE 2 is commonly used as a modem, LAN, a SCSI, or a sound card, and has a thickness of 5.0 mm; TYPE 3 is commonly used as an ATA (Advanced Technology Attachment) hard disk drive, and has a thickness of 10.5 mm. FIG. 1 illustrates how a notebook computer is connected to a communication network in accordance with the conventional art, which includes: a mobile communication terminal 10 with access to a mobile communication service while being transported; a notebook computer 20 implementing radio communication through the mobile communication terminal 10; and a connecting unit 30 connecting a data port installed in the mobile communication terminal 10 and the notebook computer 20 to enable data communication therebetween. The mobile communication terminal 10 is capable of receiving multimedia service as well as voice communication service and character information while being transported. In general, the mobile communication terminal includes a data port for data communication, through which the mobile communication terminal 10 can function as a speaker phone, update an operating program, and transmit and/or receive data. The notebook computer 20 is a portable personal computer, in which various kinds of modems can be built therein or attached thereto for data communication with an external device. The connecting unit 30 is a cable connecting the data port of the mobile communication terminal 10 and a modem of the notebook computer 20, through which the mobile communication terminal 10 and the notebook computer 20 can conduct data communication with another computer or data unit, or conduct an Internet search using a mobile communication network. The conventional notebook computer, however, has a problem in that, since it is connected to the mobile communication terminal by a separate connecting unit, the connecting unit and the mobile phone must be separately fabricated, purchased, installed/uninstalled, and transported. Korean Patent Laid-Open Publication No. 2001-0082432 (dated Aug. 30, 2001) seeks a solution to this problem by inserting a PC card having a radio frequency unit, a CDMA processor, a memory, and an interface unit into a mobile communication terminal or into a notebook computer. More specifically, the PC card is inserted into an outer case of the mobile communication terminal for use as a mobile phone, whereas insertion of the PC card into the notebook computer enables radio data communication. Then, if a user wants to access the Internet with the notebook computer, he/she may withdraw the PC card from the mobile communication terminal and insert it into the corresponding notebook computer. The notebook computer automatically senses insertion of the PC card, and the user can then access the Internet through the notebook computer. However, because the PCMCIA TYPE 2 card is 54 mm wide by 85.6 mm long by 5 mm thick, based on the pertinent industrial standards, a problem arises in that it is difficult to mount the radio frequency unit, the CDMA processor, the memory, the interface unit, and other components on the face of the PC card. Additionally, the PC card does not function by itself, and needs a dedicated terminal case for its use, causing inconvenience in that the dedicated terminal case must also be transported. The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background. SUMMARY OF THE INVENTION An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter. Therefore, an object of the present invention is to provide a radio modem terminal for mobile communication which can use an easily foldable display unit. An object of the present invention is to provide a radio modem terminal for mobile communication which can use an easily foldable power supply unit. An object of the invention is to provide a radio modem terminal for mobile communication which can use includes a PC card having a function of a mobile phone. An object of the present invention is to provide a radio modem terminal for mobile communication that can be mounted at a notebook computer by having in a PC card a switch for selecting charging/discharging of a power supply unit. To achieve at least the above objects in whole or in parts, there is provided a radio modem terminal for a mobile communication including: a main body having a functional unit for voice communication; a power supply unit hinged at one side of the main body forming a foldable type device; and a display unit hinged at one side of the main body and positioned between the power supply unit and the main body. To achieve at least these advantages in whole or in parts, there is further provided a radio modem terminal for a mobile communication including: an RF unit for processing an RF input signal; a user interface for interfacing a signal transmitted to and received from a display unit; a memory unit storing various data for operating a radio modem terminal for a mobile communication; an audio interface unit for processing a voice signal; a PCMCIA interface unit for interfacing a signal transmitted and received through the user interface unit on the basis of the PCMCIA standard; a controller for monitoring a signal transmitted and received between functional units and controlling a corresponding operation; and a connector for transmitting to and receiving from a notebook computer by being connected thereto. The present invention can be achieved in whole or in part by a radio modem terminal for mobile communication, including, a main body comprising a functional unit configured to provide voice communication capability, a power supply unit, wherein one side of the power supply unit is configured to be rotatably connected to one side of the main body, and a display unit, wherein one side of the display unit is configured to be rotatably connected to the one side of the main body, and wherein the display unit is positioned between the power supply unit and the main body. The present invention can be further achieved in whole or in part by a radio modem terminal for a mobile communication, including, an RF unit configured to process an RF input signal, a user interface configured to interface a signal transmitted to and received from a display unit, a memory unit configured to store operating data, an audio interface unit configured to process a voice signal, a PCMCIA interface unit configured to interface a signal transmitted and received through the user interface unit based on the PCMCIA standard, a controller configured to monitor a signal transmitted and received between functional units of the radio modem terminal and to control a corresponding operation, and a connector configured to connect the radio modem terminal to a notebook computer, wherein the connector is further configured to transmit a plurality of signals to and receive a plurality of signals from the notebook computer when they are connected. The present invention can be further achieved in whole or in part by a radio modem terminal for mobile communication, including, a main body, comprising a PC card, a power supply unit rotatably connected to the main body, and a display unit rotatably connected to the main body and the power supply unit. Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: FIG. 1 illustrates how data of a notebook computer is transmitted and received in accordance with the conventional art; FIG. 2 illustrates an external construction of a radio modem terminal for mobile communication in accordance with an embodiment of the present invention; FIG. 3 is a block diagram of the inner construction of the radio modem terminal for mobile communication in accordance with an embodiment of the present invention; and FIG. 4 is a schematic view of a switch of the radio modem terminal for mobile communication in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS As shown in FIG. 2, a radio modem terminal for mobile communication of the present invention includes: a PC card 100, a display unit 200 hinged at one side of the PC card 100; and a power supply unit 300 hinged at the part where the PC card 100 and the display unit 200 are coupled. The PC card 100 is 54 mm wide by 85.6 mm long by 5 mm thick, as required for a standard TYPE 2 PC card, and the various functional parts required by a mobile communication terminal are included in the PC card 100, the PC card with the function parts mounted thereon constituting a main body 500. The display unit 200 and the power supply unit 300 are attached at one side of the main body 500. The display unit 200 and the power supply unit 300 are rotated by a hinge at the other end of the PC card 100, and are opened or closed by the user as necessary. The display unit 200 is formed as a touch pad so that it can perform an input/output function without a keypad. A connector 170 is provided at one side of the main body 500 for connection with other peripheral devices. The connector 170 has 68 pins as defined by the PC card standard. In order for the mobile communication terminal using the PC card 100 to be connected to a data processing unit such as the notebook computer 400 to conduct radio communication, the notebook computer 400 includes a socket 410 that is able to accommodate the 68 pin connector 170. FIG. 3 is a block diagram of the inner construction of the radio modem terminal for mobile communication in accordance with an embodiment of the present invention, in which the radio modem terminal for mobile communication and the notebook computer 400 are connected to each other. As shown in FIG. 3, the radio modem terminal comprises: a controller 110 for monitoring and controlling each functional unit of the radio modem terminal; an RF (Radio Frequency) unit 120 for processing a transmission and reception radio frequency signal; a display unit 200 for inputting and displaying information based on user selection; a user interface unit 130 for interfacing information inputted through the display unit 200; a memory unit 140 for storing various programs and data for operating the mobile communication terminal; an audio interface unit 150 for processing a voice signal to enable voice communication; a PCMCIA interface unit 160 connected to the user interface unit 130 and interfacing an inputted signal to a signal based on the PCMCIA standard; a connector 170 connected to the notebook computer 400 to transmit and receive a signal of the PCMCIA interface unit 160 to and from an external device; and a power supply unit 300 for supplying power to the radio modem terminal. The notebook computer 400 includes: a socket 410 for connecting the connector 170 of the main body 500 to the notebook computer 400; a notebook interface unit 420 for interfacing with the socket 410 and transmitting and receiving signals through the socket 410; a notebook power supply unit 430 for supplying operating power to the radio modem terminal through the socket 410 and supplying operating power to the notebook computer 400; and a charging unit 440 for charging the power supply unit 300 connected to the radio modem terminal through the socket 410. If the radio modem terminal is connected to the notebook computer 400, the controller 110 controls the radio modem terminal such that the radio modem terminal is operated as a radio modem, whereas if the radio modem terminal transmits and receives a voice signal through the audio interface 150, the controller 110 controls the radio modem terminal such that the radio modem terminal is operated as a mobile communication terminal. The display unit 200 can be constructed as a liquid crystal display (LCD), and preferably includes a touch pad. The user interface 130 receives a dial signal, a search signal, or transmission and reception control signal that is input by the user through the display unit 200, transmits the signal to the controller 110, and displays an operation state of the radio modem terminal on the display unit 200. The memory unit 140 stores programs or data required for the controller 110 to control each functional unit of the radio modem terminal, and activates and outputs stored programs or data based on a request from the controller 110. If the radio modem terminal is used as a mobile communication terminal, the audio interface unit 150 processes a transmitted and received voice signal. The PCMCIA interface unit 160 is required if the radio modem terminal is used as a radio modem. In this case, the PCMCIA interface unit 160 is connected to the controller 110 through the user interface unit 130. The PCMCIA interface unit 160 processes a data communication signal based on the PCMCIA standard and transmits the signal to the notebook computer 400 through the connector 170. At this time, the connector 170 is connected to the socket 410 of the notebook computer 400. The socket 410 of the notebook computer 400 transmits a signal applied through the connector 170 of the radio modem terminal to the notebook interface unit 410. The socket 410 also transmits various signals generated by the notebook computer 400 to the radio modem terminal through the connector 170. The notebook power supply unit 430 supplies basic power to operate each functional part of the notebook computer 400. The power supply unit 430 also supplies power to the radio modem terminal when the socket 410 and the connector 170 are connected. The charging unit 440 charges the power supply unit 300 of the radio modem terminal for mobile communication, while the notebook power supply unit 430 supplies power to the radio modem terminal while the notebook computer 400 and the radio modem terminal are connected. At this time, the notebook power supply unit 430 and the charging unit 440 are connected to the pins of the socket 410, and the pins of the socket 410 are connected to corresponding pins of the connector 170. FIG. 4 is a detailed view of a switch of the radio modem terminal for mobile communication in accordance with an embodiment of the present invention. As shown in FIG. 4, the radio modem terminal for mobile communication includes a switch 180 for connecting the connector 170 and the power supply unit 300. The switch 180 operates by automatically sensing a connection between the radio modem terminal and the notebook computer 400. That is, when the radio modem terminal and the notebook computer 400 are connected, terminals ‘a’ and ‘b’ of the switch 180 are connected. When sensing this connection, the switch 180 supplies operating power from the notebook power supply unit 430 to the radio modem terminal. It also supplies power from the charging unit 440 to the power supply unit 300 in order to charge it. If, however, the radio modem terminal is not connected to the notebook computer 400, the terminals ‘a’ and ‘c’ of the switch 180 are connected, causing the notebook power supply unit 430 to be shorted. Operating power outputted from the power supply unit 300 is then supplied to each functional part of the radio modem terminal, and accordingly, the radio modem terminal operates as a mobile communication terminal. The operation of the radio modem terminal will now be described in detail. The display unit 200 and the power supply unit 300 of the radio modem terminal are opened from the PC card 100, and the connector 170 of the PC card 100 is installed in the socket 410 of the notebook computer 400. As the terminals ‘a’ and ‘b’ are connected in the switch 180 of the radio modem terminal, the radio modem terminal would use power supplied by the notebook computer 400 as its operating power, and would operate in the PC card mode according to the user's manipulation. When the radio modem terminal is intended to be used as a mobile communication terminal, the display unit 200 is opened and the touch pad is manipulated just like a typical foldable type mobile communication device. Then, the radio modem terminal senses a non-connection of the socket 410 of the notebook computer 400 to the connector 170, and accordingly, it is switched to the mobile communication terminal mode and uses power supplied by the power supply unit 300 for its operating power. The radio modem terminal can be also used as a mobile communication terminal in the PC card mode. That is, while the radio modem terminal is not performing a radio data communication, the user may initiate voice communication by using the display unit 200 and a mobile communication terminal headset (not shown). As so far described, the radio modem terminal for mobile communication has an advantage in that, by integrating the mobile communication terminal and the PC card into one body, the user does not need to carry a PC card separate from the mobile communication terminal. Accordingly, this approach is not only economical but also more convenient when being transported and used. The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.
|
H
|
H04
|
H04B
|
1
|
38
|
|||
11943775
|
US20080123759A1-20080529
|
CHANNEL ESTIMATING APPARATUS AND METHOD FOR USE IN A BROADBAND WIRELESS COMMUNICATION SYSTEM
|
ACCEPTED
|
20080514
|
20080529
|
[]
|
H04L2728
|
["H04L2728", "H04L2706"]
|
8040987
|
20071121
|
20111018
|
375
|
349000
|
75458.0
|
PEREZ
|
JAMES
|
[{"inventor_name_last": "OH", "inventor_name_first": "Jeong-Tae", "inventor_city": "Yongin-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "BYUN", "inventor_name_first": "Myung-Kwang", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "JEON", "inventor_name_first": "Jae-Ho", "inventor_city": "Seongnam-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "MAENG", "inventor_name_first": "Seung-Joo", "inventor_city": "Seongnam-si", "inventor_state": "", "inventor_country": "KR"}]
|
A Channel estimating apparatus and method for use in a broadband wireless communication system are provided. The receiving method includes determining a control unit for a channel estimation using burst allocation information of selected sectors; extracting pilot symbols from received data based on the control unit; and acquiring a channel estimate value for each transmission unit by performing a Joint Channel Estimation (JCE) with the extracted pilot symbols that are based on the control unit.
|
1. A receiver in a broadband wireless communication comprising: a determiner for determining a control unit for a channel estimation using burst allocation information of selected sectors; an extractor for extracting pilot symbols from received data based on the control unit; and a channel estimator for acquiring a channel estimate value for each transmission unit by performing a Joint Channel Estimation (JCE) with the pilot symbols output from the extractor that are based on the control unit. 2. The receiver of claim 1, further comprising: a compensator for channel-compensating received burst data using the channel estimate values output from the channel estimator. 3. The receiver of claim 1, wherein the determiner counts a number of consecutive transmission units from an end of a previous control unit in a time axis with respect to each of the sectors, and sets the smallest value of the counted transmission unit numbers as a length of the control unit. 4. The receiver of claim 1, wherein the determiner determines the control unit to maximize a number of pilot symbols for the JCE. 5. The receiver of claim 1, wherein the control unit comprises consecutive Orthogonal Frequency Division Multiplexing (OFDM) symbols in a time axis and adjacent subcarriers in a frequency axis. 6. The receiver of claim 1, wherein, when the number of the selected sectors is 3 and the number of the pilot symbols in the control unit is 4, the channel estimator estimates the channel based on the following equation: h ^ = ( P H P ) - 1 P H Y P = [ P 0 ( 0 ) P 1 ( 0 ) P 2 ( 0 ) P 0 ( 1 ) P 1 ( 1 ) P 2 ( 1 ) P 0 ( 2 ) P 1 ( 2 ) P 2 ( 2 ) P 0 ( 3 ) P 1 ( 3 ) P 2 ( 3 ) ] where Pc(k) is a scrambling code value applied to a k-th pilot tone of a c-th sector, Y is a receive vector, and ĥ is a vector constituted by channel estimate values of sectors. 7. The receiver of claim 1, wherein the transmission unit is a tile of a Partial Usage of SubCarrier (PUSC) subchannel or a slot of an Adaptive Modulation and Coding (AMC) subchannel. 8. The receiver of claim 1, wherein the channel estimator performs the JCE using a window sliding scheme with respect to one control unit. 9. The receiver of claim 1, wherein the burst allocation information comprises at least one of a position of an allocated resource, a size of the allocated resource, a subchannel scheme, and a scrambling code value masked to the pilot symbol. 10. The receiver of claim 2, further comprising: an OFDM demodulator for Fast Fourier Transform (FFT)-processing the received data; a descrambler for descrambling data output from the OFDM demodulator with codes uniquely allocated to the sectors; and a subchannel demapper for extracting burst data to be demodulated from the data output from the descrambler and providing the extracted burst data to the channel compensator. 11. The receiver of claim 2, further comprising: a demodulator for demodulating data output from the channel compensator; and a decoder for decoding data output from the demodulator. 12. A receiving method in a broadband wireless communication system, comprising: determining a control unit for a channel estimation by using burst allocation information of selected sectors; extracting pilot symbols from received data based on the control unit; and acquiring a channel estimate value for each transmission unit by performing a Joint Channel Estimation (JCE) with the extracted pilot symbols that are based on the control unit. 13. The receiving method of claim 12, further comprising: channel-compensating received burst data using the acquired channel estimate values. 14. The receiving method of claim 12, wherein the determining a control unit comprises: counting a number of consecutive transmission units from an end of a previous control unit in a time axis with respect to each of the sectors; and setting the smallest value of the counted transmission unit numbers as a length of the control unit. 15. The receiving method of claim 12, wherein the determining a control unit comprises determining the control unit to maximize a number of pilot symbols for the JCE. 16. The receiving method of claim 12, wherein the control unit comprises consecutive Orthogonal Frequency Division Multiplexing (OFDM) symbols in a time axis and adjacent subcarriers in a frequency axis. 17. The receiving method of claim 12, wherein, when the number of the selected sectors is 3 and the number of the pilot symbols in the control unit is 4, the channel estimate value is calculated based on the following equation: h ^ = ( P H P ) - 1 P H Y P = [ P 0 ( 0 ) P 1 ( 0 ) P 2 ( 0 ) P 0 ( 1 ) P 1 ( 1 ) P 2 ( 1 ) P 0 ( 2 ) P 1 ( 2 ) P 2 ( 2 ) P 0 ( 3 ) P 1 ( 3 ) P 2 ( 3 ) ] where Pc(k) is a scrambling code value applied to a k-th pilot tone of a c-th sector, Y is a receive vector, and h is a vector constituted by channel estimate values of sectors. 18. The receiving method of claim 12, wherein the transmission unit is a tile of a Partial Usage of SubCarrier (PUSC) subchannel or a slot of an Adaptive Modulation and Coding (AMC) subchannel. 19. The receiving method of claim 12, wherein the channel estimate value acquiring comprises performing the JCE using a window sliding scheme with respect to each control unit. 20. The receiving method of claim 12, wherein the burst allocation information comprises at least one of a position of an allocated resource, a size of the allocated resource, a subchannel scheme, and a scrambling code value masked to the pilot symbol. 21. The receiving method of claim 13, further comprising: OFDM-demodulating by Fast Fourier Transform (FFT)-processing the received data; descrambling the OFDM-demodulated data with codes uniquely allocated to the sectors; and extracting the burst data from the descrambled data. 22. The receiving method of claim 13, further comprising: demodulating the channel-compensated data; and restoring an information bit stream by decoding the demodulated data.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a receiver and a receiving method for use in a wireless communication system. More particularly, the present invention relates to a channel estimating apparatus and method which takes into account neighbor sector or cell interference in a broadband multiple access wireless communication system. 2. Description of the Related Art Communication systems were originally developed to provide voice services. Now, communication systems are being developed to provide packet data services and various multimedia services as well as voice services. An exemplary system capable of providing wireless packet data services is a third generation (3G) mobile communication system. The 3G mobile communication system provides various high speed multimedia services. The 3G mobile communication system distinguishes users using a Code Division Multiple Access (CDMA) scheme. The CDMA scheme distinguishes channels by allocating different orthogonal codes to users or to data transmitted to users. However, the 3G mobile communication system fails to provide high speed data with high quality because of a lack of available codes. In other words, since the amount of usable codes are restricted, transmission rates are limited. To address this problem, researches and developers of mobile communication systems are considering a next-generation communication system which is referred to as the fourth generation (4G) broadband wireless communication system. The broadband wireless communication system is able to classify and transmit users or data to be sent, using an Orthogonal Frequency Division Multiple Access (OFDMA) scheme. The 4G wireless communication system features a high transmission rate of up to 100 Mbps. Furthermore, unlike the 3G system, the 4G system can provide services having various level of Quality of Service (QoS). Currently, the 4 G communication system is being developed to guarantee mobility and QoS in a Broadband Wireless Access (BWA) communication system such as wireless Local Area Network (LAN) system and wireless Metropolitan Area Network (MAN) system. Exemplary communication systems include the Institute of Electrical and Electronics Engineers (IEEE) 802.16d communication system and the IEEE 802.16e communication system. However, various other systems using the OFDMA scheme are under development. As discussed above, the broadband wireless communication system adopts the OFDMA scheme, ensures mobility, and utilizes the same frequency in every cell to increase frequency efficiency. FIG. 1 is a simplified diagram of a conventional BWA system implemented with multiple cells. In FIG. 1 , Base Station (BS) 0 , BS 1 , and BS 2 are each communicating within their respective cells 100 , 101 and 102 using the same frequency. In this situation, the multicell system has a frequency reutilization of ‘1,’ thereby increasing its frequency efficiency. However, by using the same frequency in adjacent cells, the resulting inter-cell or inter-sector interference may impair the performance of the system. For example, in view of a Mobile Station (MS) 103 communicating with BS 0 , a transmit signal of an MS 104 communicating with BS 1 of the neighboring cell and a transmit signal of an MS 105 communicating with BS 2 of the neighboring cell acts as interference signals to BS 0 . In other words, BS 0 receives the interference signals 107 and 108 in addition to the received signal 106 from MS 103 in its cell. The interference signals of the neighboring cells affects the signal of MS 103 in the corresponding cell and thus deteriorates demodulation performance. Therefore, a need exists for an apparatus and method for canceling interference caused by neighboring cells in a multicell system.
|
<SOH> SUMMARY OF THE INVENTION <EOH>An aspect of the present invention is to address at least the above problems and/or disadvantages and to provide at least the advantages below. Accordingly, an aspect of exemplary embodiments of the present invention is to provide an apparatus and method for canceling inter-cell or inter-sector interference in a broadband wireless communication system. Another aspect of exemplary embodiments of the present invention is to provide an apparatus and method for estimating channels by taking into account inter-cell or inter-sector) in a broadband wireless communication system. A further aspect of exemplary embodiments of the present invention is to provide an apparatus and method for determining a unit of channel estimation using burst allocation information of interfering cells when the channel is estimated by taking into account inter-cell or inter-sector interference in a broadband wireless communication system. The above aspects are achieved in an exemplary embodiment of the present invention by providing a receiver in a broadband wireless communication which includes a determiner for determining a control unit for a channel estimation using burst allocation information of selected sectors; an extractor for extracting pilot symbols from received data based on the control unit; and a channel estimator for acquiring a channel estimate value for each transmission unit by performing a Joint Channel Estimation (JCE) with the pilot symbols output from the extractor that re based on the control unit. According to one aspect of an exemplary embodiments of the present invention, a receiving method in a broadband wireless communication system includes determining a control unit for a channel estimation by using burst allocation information of selected sectors; extracting pilot symbols from received data based on the control unit; and acquiring a channel estimate value for each transmission unit by performing a Joint Channel Estimation (JCE) with the extracted pilot symbols that are based on the control unit. Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
|
PRIORITY This application claims the benefit under 35 U.S.C. § 119(a) of a Korean patent application filed on Nov. 23, 2006 in the Korean Intellectual Property Office and assigned Serial No. 2006-0116146, the entire disclosure of which is hereby incorporated by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver and a receiving method for use in a wireless communication system. More particularly, the present invention relates to a channel estimating apparatus and method which takes into account neighbor sector or cell interference in a broadband multiple access wireless communication system. 2. Description of the Related Art Communication systems were originally developed to provide voice services. Now, communication systems are being developed to provide packet data services and various multimedia services as well as voice services. An exemplary system capable of providing wireless packet data services is a third generation (3G) mobile communication system. The 3G mobile communication system provides various high speed multimedia services. The 3G mobile communication system distinguishes users using a Code Division Multiple Access (CDMA) scheme. The CDMA scheme distinguishes channels by allocating different orthogonal codes to users or to data transmitted to users. However, the 3G mobile communication system fails to provide high speed data with high quality because of a lack of available codes. In other words, since the amount of usable codes are restricted, transmission rates are limited. To address this problem, researches and developers of mobile communication systems are considering a next-generation communication system which is referred to as the fourth generation (4G) broadband wireless communication system. The broadband wireless communication system is able to classify and transmit users or data to be sent, using an Orthogonal Frequency Division Multiple Access (OFDMA) scheme. The 4G wireless communication system features a high transmission rate of up to 100 Mbps. Furthermore, unlike the 3G system, the 4G system can provide services having various level of Quality of Service (QoS). Currently, the 4 G communication system is being developed to guarantee mobility and QoS in a Broadband Wireless Access (BWA) communication system such as wireless Local Area Network (LAN) system and wireless Metropolitan Area Network (MAN) system. Exemplary communication systems include the Institute of Electrical and Electronics Engineers (IEEE) 802.16d communication system and the IEEE 802.16e communication system. However, various other systems using the OFDMA scheme are under development. As discussed above, the broadband wireless communication system adopts the OFDMA scheme, ensures mobility, and utilizes the same frequency in every cell to increase frequency efficiency. FIG. 1 is a simplified diagram of a conventional BWA system implemented with multiple cells. In FIG. 1, Base Station (BS) 0, BS 1, and BS 2 are each communicating within their respective cells 100, 101 and 102 using the same frequency. In this situation, the multicell system has a frequency reutilization of ‘1,’ thereby increasing its frequency efficiency. However, by using the same frequency in adjacent cells, the resulting inter-cell or inter-sector interference may impair the performance of the system. For example, in view of a Mobile Station (MS) 103 communicating with BS 0, a transmit signal of an MS 104 communicating with BS 1 of the neighboring cell and a transmit signal of an MS 105 communicating with BS 2 of the neighboring cell acts as interference signals to BS 0. In other words, BS 0 receives the interference signals 107 and 108 in addition to the received signal 106 from MS 103 in its cell. The interference signals of the neighboring cells affects the signal of MS 103 in the corresponding cell and thus deteriorates demodulation performance. Therefore, a need exists for an apparatus and method for canceling interference caused by neighboring cells in a multicell system. SUMMARY OF THE INVENTION An aspect of the present invention is to address at least the above problems and/or disadvantages and to provide at least the advantages below. Accordingly, an aspect of exemplary embodiments of the present invention is to provide an apparatus and method for canceling inter-cell or inter-sector interference in a broadband wireless communication system. Another aspect of exemplary embodiments of the present invention is to provide an apparatus and method for estimating channels by taking into account inter-cell or inter-sector) in a broadband wireless communication system. A further aspect of exemplary embodiments of the present invention is to provide an apparatus and method for determining a unit of channel estimation using burst allocation information of interfering cells when the channel is estimated by taking into account inter-cell or inter-sector interference in a broadband wireless communication system. The above aspects are achieved in an exemplary embodiment of the present invention by providing a receiver in a broadband wireless communication which includes a determiner for determining a control unit for a channel estimation using burst allocation information of selected sectors; an extractor for extracting pilot symbols from received data based on the control unit; and a channel estimator for acquiring a channel estimate value for each transmission unit by performing a Joint Channel Estimation (JCE) with the pilot symbols output from the extractor that re based on the control unit. According to one aspect of an exemplary embodiments of the present invention, a receiving method in a broadband wireless communication system includes determining a control unit for a channel estimation by using burst allocation information of selected sectors; extracting pilot symbols from received data based on the control unit; and acquiring a channel estimate value for each transmission unit by performing a Joint Channel Estimation (JCE) with the extracted pilot symbols that are based on the control unit. Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The above and other aspects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. 1 illustrates a conventional multicell Broadband Wireless Access (BWA) system; FIG. 2 illustrates a receiver in a BWA system according to an exemplary embodiment of the present invention; FIGS. 3A and 3B illustrate a subchannel structure for uplink transmission in the BWA system, according to an exemplary embodiment of the present invention; FIG. 4 illustrates a channel estimator according to an exemplary embodiment of the present invention; FIG. 5 illustrates operations of the channel estimator according to an exemplary embodiment of the present invention; FIG. 6 illustrates a control unit determining method for channel estimation, according to an exemplary embodiment of the present invention; and FIG. 7 illustrates a channel estimation method within the control unit for channel estimation, according to an exemplary embodiment of the present invention. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features and structures. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness. Exemplary embodiments of the present invention provide a channel estimation technique which takes into account inter-cell or inter-sector interference in a Broadband Wireless Access (BWA) communication system. While a BWA communication system is illustrated by way of example, the present invention is applicable to any multicell communication system. While a receiver (uplink) of a Base Station (BS) is explained by way of example, the exemplary embodiments of present invention are applicable to any receiver of a BS and a user terminal. FIG. 2 illustrates a receiver in a BWA system according to an exemplary embodiment of the present invention. The receiver of FIG. 2 includes a Radio Frequency (RF) processor 200, an Orthogonal Frequency Division Multiplexing (OFDM) demodulator 202, a descrambler 204, a subchannel demapper 206, a channel compensator 208, a demodulator 210, a decoder 212, a Cyclic Redundancy Check (CRC) examiner 214, and a channel estimator 216. Hereafter, to ease the understanding of the present invention, the cancellation of inter-sector interference is described. However, exemplary embodiments of the present invention are equally applicable to inter-cell interference. The RF processor 200 includes components such as a filter and a frequency converter. The RF processor 200 converts an RF signal received by an antenna into a baseband signal and converts the baseband signal into a digital signal. The OFDM demodulator 202 outputs frequency-domain data by Fast Fourier Transform (FFT)-processing the sample data output from the RF processor 200. The descrambler 204 descrambles the data output from the OFDM demodulator 202 with codes that are uniquely allocated to sectors. The subchannel demapper 206 extracts and arranges data of a burst to be demodulated from the data output from the descrambler 204. The channel estimator 216 receives burst allocation information of the selected sectors, such as the sectors interfering with each other. Further, the channel estimator 216 determines a control unit for the channel estimation using the burst allocation information of the sectors. The channel estimator 216 extracts pilot symbols from the data output from the OFDM demodulator 202 based on the determined control unit. Moreover, the channel estimator 216 acquires a channel estimate value by a certain unit, such as by the tile in the case of a Partial Usage of SubCarrier (PUSC) subchannel. The channel estimator 216 acquires a channel estimate value by estimating the channel with the extracted pilot symbols, as discussed in further detail below. That is, the channel estimator 216 acquires the channel estimate values of a desired sector and the interfering sectors. Next, the channel estimator 216 calculates a total channel value for the burst to be demodulated using the acquired channel estimate values, and provides the calculated channel value to the channel compensator 208. The channel estimator 216 will be described in further detail below by referring to FIG. 4. The channel compensator 208 channel-compensates the data output from the subchannel demapper 206 using the channel value provided by the channel estimator 216. The demodulator 210 demodulates the data output from the channel compensator 208. Herein, the demodulator 210 generates and outputs a Log Likelihood Ratio (LLR) value for use in soft decision decoding. The decoder 212 outputs an information bit stream by decoding the data from the demodulator 210. The CRC examiner 214 extracts a CRC code from the information bit stream output from the decoder 212 and checks for error by comparing a CRC code generated from the received information bit stream and the extracted CRC code. FIGS. 3A and 3B illustrate a subchannel structure for an uplink transmission in the BWA system. FIG. 3A depicts a tile of a PUSC subchannel and FIG. 3B depicts a slot of an Adaptive Modulation and Coding (AMC) subchannel. The tile of FIG. 3A includes 4 consecutive subcarriers (tones) in a frequency axis and 3 OFDM symbols in a time axis. That is, one tile includes 12 (=4 tones×3 OFDM symbols) tones in total. At this time, 8 tones are data tones and 4 tones are pilot tones. The pilot tones carry a preset signal (pilot signal) that is known to a Base Station (BS) and a terminal and their positions are predefined. A channel estimate value for 8 data symbols of the tile is calculated using the 4 pilot symbols. The slot of FIG. 3B includes 18 adjacent tones in the frequency axis and 3 consecutive OFDM symbols in the time axis. That is, one slot includes 54 (=18 tones×3 OFDM symbols) tones in total. Among them, 6 tones are pilot tones and 48 tones are data tones. Now, an example is described where the PUSC subchannel structure of FIG. 3A is used. When inter-sector interference is present, severe performance deterioration of the channel estimation may result. Thus, to overcome this problem, a Joint Channel Estimation (JCE) in consideration of the inter-sector interference is performed based on Equation (1). Equation (1) assumes that there are 3 sectors. P = [ P 0 ( 0 ) P 1 ( 0 ) P 2 ( 0 ) P 0 ( 1 ) P 1 ( 1 ) P 2 ( 1 ) P 0 ( 2 ) P 1 ( 2 ) P 2 ( 2 ) P 0 ( 3 ) P 1 ( 3 ) P 2 ( 3 ) ] h ^ = ( P H P ) - 1 P H Y ( 1 ) In Equation (1), the matrix P arranges a scrambling pattern applied to the tile of the three sectors. In the element Pc(k) of the matrix, c indicates a sector index (c=0˜C−1) and k indicates a pilot tone index (k=0˜K−1). Accordingly, the value Pc(k) can have a value of +1 or −1. Y, which indicates a received signal, is a vector comprising received signal values with respect to the 4 pilot tones. ĥ indicates a vector of the channel estimate values for the corresponding tile. The variables in Equation (1) are generalized based on the number of the interfering sectors and the number of the pilot tones in the channel estimate unit as follows: P=[number of pilot tones×number of the interfering sectors] matrix Y=[number of the pilot tones] vector ĥ=[number of the interfering sectors] vector When the channel estimation is performed using Equation (1), a channel estimate value is acquired with respect to each interfering sector per tile. When there is no inverse matrix ((PH P)−1), it is impossible to get the channel estimate value. When using 4 pilot tones (K=4), there is a 12.5% probability that no inverse matrix exits for two sectors (C=2). Furthermore, when using 4 pilot tones (K=4), there is a 34.4% probability that no inverse matrix will be acquired for three sectors (C=3). As such, the number of tiles corresponds to the probability of not acquiring the channel estimation. With 4 tones, up to four sectors (C=4) can be distinguished. In this case, there is a 59.0% probability that no inverse matrix is acquired. In Equation (1), since the number of pilot tones determines the maximum number of channel-estimatable sectors (or cells) and the probability of the inverse matrix, it is necessary to determine a unit of the channel estimation by taking into account these factors. FIG. 4 illustrates the channel estimator 216 according to an exemplary embodiment of the present invention. The channel estimator 216 of FIG. 4 includes a control unit determiner 400, a pilot symbol extractor 402, a first channel estimator 404, and a second channel estimator 406. The control unit determiner 400 receives the burst allocation information of the selected sectors (the interfering sectors) and determines the control unit of the channel estimation using the burst allocation information. Herein, the burst allocation information indicates the position and the size of the allocated resource, the adopted subchannel scheme, and the scrambling code values masked to the pilot symbols. The determination of the control unit will be explained in further detail below by referring to FIG. 6. The pilot symbol extractor 402 extracts and outputs the pilot symbols from the data output from the OFDM demodulator 202 based on the determined control unit. The first channel estimator 404 acquires the channel estimate values per tile by estimating the channel with the pilot symbols that are based on the control unit, wherein the pilot symbols are provided from the pilot symbol extractor 402 based on Equation (1). The second channel estimator 406 calculates the total channel values for the burst to be demodulated using the tile channel estimate value per tile provided from the first channel estimator 404, and provides the calculated channel values to the channel compensator 208. The channel values for the entire subcarriers of the burst can be acquired by applying the tile channel estimate value to every tone (subcarrier) of the corresponding tile in the simplest manner, or by linearly interpolating the channel estimate values. FIG. 5 illustrates detailed operations of the channel estimator 216 according to an exemplary embodiment of the present invention. The channel estimator 216 acquires the burst allocation information of the selected sectors (the interfering sectors) in step 501. Herein, the burst allocation information signifies the position and the size of the allocated resource, the adopted subchannel scheme, and the scrambling code values masked to the pilot symbols. Upon acquiring the burst allocation information of the selected sectors, the channel estimator 216 determines a control unit for the channel estimation using the burst allocation information of the sectors in step 503. The control unit is the unit which maximizes the number of pilot tones allowing the channel estimation with respect to the selected sectors. For example, in the case of the PUSC subchannel structure which performs the subchannel rotation per three OFDM symbols, the tile is not consecutively allocated in both the time and frequency axes. Accordingly, the control unit in the frequency axis is one tile (4 tones) and the control unit in the time axis is also one tile (3 OFDM symbols). For example, in the PUSC subchannel which consecutively allocates the tiles in the time axis without the subchannel rotation, the control unit in the frequency axis is one tile (4 tones) and the control unit in the time axis is set to a length allowing for the channel estimation in the corresponding sector set. For example, in the uplink AMC subchannel which consecutively allocates resources along the time axis in a specific frequency domain, the control unit in the frequency axis is at least one bean (9 tones) and the control unit in the time axis is set to a length allowing for the channel estimation in the corresponding sector set. As described above, when the control unit of the channel estimation is determined, the channel estimator 216 extracts the pilot symbols from the OFDM-demodulated data based on the determined control unit in step 505. In step 507, the channel estimator 216, based on Equation (1), estimates the channels using the pilot symbols extracted that are based on the control unit. That is, the channel estimator 216 acquires the channel estimate values of the desired sector and the interfering sectors per tile. Next, in step 509, the channel estimator 216 calculates the total channel value for the burst to be demodulated using the acquired channel estimate values and provides the calculated channel values to the channel compensator 208. The channel value of the entire burst subcarrier can be calculated by merely applying the tile channel estimate values to every subcarrier of the corresponding tile, or by linearly interpolating the acquired channel estimate values. By way of example, a determination of a control unit of the channel estimation is described below. FIG. 6 illustrates a control unit determining method for the channel estimation according to an exemplary embodiment of the present invention. The PUSC subchannel structure is as an example in the description below. It is assumed that there are 3 cells (or sectors) interfering with each other and that a BS0 demodulates the received signal. Further, it is assumed that BS 1 and BS2 interfere with the BS0. It is assumed that one burst 500; that is, 15 PUSC tiles that are allocated to the BS0. It is assumed that 3 bursts 502, 503 and 504; that is, 3 PUSC tiles 502, 3 PUSC tiles 503, and 9 PUSC tiles 504 are allocated to the BS1. It is assumed that 2 bursts; that is, 2 PUSC tiles 505 and 10 PUSC tiles 506 are allocated to the BS2. In this situation, 7 control units can be generated as shown in FIG. 6. The basic unit in the frequency axis is a tile (4 tones) and the basic unit in the time axis is 3 OFDM symbols. After the number of consecutive tiles (the number of tiles belonging to the same burst) along the time axis are counted from a certain point with respect to each BS, the smallest number of the counted tile numbers is set to the control unit length, which is described below. (1) Set the 0-th tile in the frequency axis and the time axis to the start. (2) Count the number of consecutive tiles in the time axis from a certain start point with respect to each sector. (3) Set the smallest value among the counted tile numbers to the control unit length. (4) Set a tile following the set control unit as the start. (5) When the control unit in the time axis is determined, move to the next frequency band and return to (2). In FIG. 6, the BS0 occupies 4 consecutive tiles from the 0-th tile, the BS1 occupies 3 consecutive tiles from the 0-th tile, and the BS2 occupies 2 consecutive tiles from the 0-th file. Accordingly, the length of the control unit is set to 2 and the start point is set to the second tile. Since the BS0 occupies 2 consecutive tiles from the second tile, the BS1 occupies one consecutive tile from the second tile, and the BS2 occupies 2 consecutive tiles from the second tile, the length of the control unit is set to 1. When the control unit in the time axis is finally determined, the control unit of the frequency axis is determined in the similar way. FIG. 7 illustrates an exemplary channel estimation method within the control unit of the channel estimation. There are 8 tiles in the control unit and the channel estimate value is generated by the tile unit. The channel estimation is carried out in the 3-tile (window) sliding scheme using Equation (1). Herein, the sliding scheme estimates the channel using every pilot symbol before and after the tile to be estimated. When there is no front tile H(0) or no preceding tile H(7), the channel is estimated with two tiles. When there is neither the front tile nor the preceding tile, the channel can be estimated merely with the tile to be estimated. In FIG. 7, the channel estimate value H(0) of the 0-th tile is calculated using the pilot symbols of the 0-th tile and the first tile (8 pilot symbols in total) and the channel estimate value H(1) of the first tile is calculated using the pilot symbols of the 0-th tile, the first tile, and the second tile (12 pilot symbols in total). The channel estimate value H(2) of the second tile is calculated using the pilot symbols of the first tile, the second tile and the third tile, and the channel estimate value H(3) of the third tile is calculated using the pilot symbols of the second tile, the third tile, and the fourth tile. The channel estimate value H(4) of the fourth tile is calculated using the pilot symbols of the third tile, the fourth tile, and the fifth tile, and the channel estimate value H(5) of the fifth tile is calculated using the pilot symbols of the fourth tile, the fifth tile, and the sixth tile. The channel estimate value H(6) of the sixth tile is calculated using the pilot symbols of the fifth tile, the sixth tile, and the seventh tile, and the channel estimate value H(7) of the seventh tile is calculated using the pilot symbols of the sixth tile and the seventh tile. As indicated earlier in Equation (1), the channel estimate value calculated for each tile is the vector constituted by the channel values of the desired sector and the interfering sectors. As such, when the channel is estimated using 3 tiles, 12 pilot symbols in total can be used. When the channel is estimated using 3 AMC slots, 18 pilot symbols in total can be used. The method in FIG. 7 is a merely an example. Note that the channel estimation scheme in the control unit may vary according to the type of radio channel, the terminal environment (data rate), the data service type, and the Quality of Service (QoS). As set forth above, by considering the interference in the multicell wireless communication system where the inter-cell or the inter-sector interference exists, the channel estimation can be accurately carried out. Namely, the present invention can enhance the demodulation performance (decoding performance) by performing accurate channel estimation and can increase the cell capacity. Certain aspects of the present invention can also be embodied as computer readable code on a computer readable recording medium. A computer readable recording medium is any data storage device that can store data which can be thereafter read by a computer system. Examples of the computer readable recording medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and carrier waves (such as data transmission through the Internet). The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. Also, functional programs, code, and code segments for accomplishing the present invention can be easily construed by programmers skilled in the art to which the present invention pertains. While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.
|
H
|
H04
|
H04L
|
27
|
28
|
|||
11846874
|
US20090057849A1-20090305
|
INTERCONNECT IN A MULTI-ELEMENT PACKAGE
|
ACCEPTED
|
20090218
|
20090305
|
[]
|
H01L2348
|
["H01L2348", "H01L2156"]
|
7838420
|
20070829
|
20101123
|
438
|
672000
|
67894.0
|
DANG
|
PHUC
|
[{"inventor_name_last": "Tang", "inventor_name_first": "Jinbang", "inventor_city": "Chandler", "inventor_state": "AZ", "inventor_country": "US"}, {"inventor_name_last": "Frear", "inventor_name_first": "Darrel R.", "inventor_city": "Phoenix", "inventor_state": "AZ", "inventor_country": "US"}, {"inventor_name_last": "Lytle", "inventor_name_first": "William H.", "inventor_city": "Chandler", "inventor_state": "AZ", "inventor_country": "US"}]
|
A packaged semiconductor device includes an interconnect layer over a first side of a polymer layer, a semiconductor device surrounded on at least three sides by the polymer layer and coupled to the interconnect layer, a first conductive element over a second side of the polymer layer, wherein the second side is opposite the first side, and a connector block within the polymer layer. The connector block has at least one electrical path extending from a first surface of the connector block to a second surface of the connector block. The at least one electrical path electrically couples the interconnect layer to the first conductive element. A method of forming the packaged semiconductor device is also described.
|
1. A packaged semiconductor device comprising: an interconnect layer over a first side of a polymer layer; a semiconductor device surrounded on at least three sides by the polymer layer and coupled to the interconnect layer; a first conductive element over a second side of the polymer layer, wherein the second side is opposite the first side; and a connector block within the polymer layer, having at least one electrical path extending from a first surface of the connector block to a second surface of the connector block, and electrically coupling the interconnect layer to the first conductive element through the at least one electrical path. 2. The packaged semiconductor device of claim 1, wherein the connector block comprises an insulating material surrounding the at least one electrical path. 3. The packaged semiconductor device of claim 1, wherein the connector block has at least two coaxial electrical paths. 4. The packaged semiconductor device of claim 1, wherein the at least one electrical path is a ground path and the first conductive element is a ground plane. 5. The packaged semiconductor device of claim 1, wherein the at least one electrical path is a signal path and the first conductive element is an antenna. 6. The packaged semiconductor device of claim 5, further comprising a second conductive element and a second electrical path, wherein the second electrical path is a ground path and the second conductive element is a ground plane. 7. The packaged semiconductor device of claim 6, further comprising a third electrical path, wherein the third electrical path is coupled to the antenna. 8. A method for forming a packaged semiconductor device, the method comprising: surrounding a semiconductor device on at least three sides by a polymer layer; forming an interconnect layer over a first side of the polymer layer and over the semiconductor device, wherein the semiconductor device is coupled to the interconnect layer; forming a conductive element over a second side of the polymer layer, wherein the second side is opposite the first side; and electrically coupling the interconnect layer to the conductive element through a connector block within the polymer layer, having at least one electrical path. 9. The method of claim 8, wherein forming the conductive element over a second side comprises plating a conductive material to form an antenna. 10. The method of claim 8, wherein: surrounding a semiconductor device on at least three sides by the polymer layer, comprises: attaching a semiconductor device to a temporary support structure; forming the polymer layer over the semiconductor device; and removing the temporary support structure after forming the polymer layer; and electrically coupling the interconnect layer, comprises: attaching the connector block to the temporary support structure before forming the polymer layer; removing a portion of the polymer layer to expose a surface of the connector block; and forming the interconnect layer over the surface of the connector block while forming the interconnect layer over the first side of the polymer layer. 11. The method of claim 10, further comprising: depositing a dielectric layer over the surface of the connector block; and forming a via in the dielectric layer, wherein the via is electrically coupled to the connector block and the conductive element. 12. The method of claim 8, wherein the at least one electrical path is selected from the group consisting of a ground path and a signal path. 13. The method of claim 8, wherein the first conductive element is selected from a group consisting of a ground plane and an antenna. 14. The method of claim 8, wherein the at least one electrical path comprises at least two coaxial electrical paths. 15. A method for forming a packaged semiconductor device, the method comprising: attaching a semiconductor device to a temporary support structure; attaching a connector block to the temporary support structure, wherein the connector block has at least one electrical path; forming an encapsulant over the connector block and the semiconductor device; removing a portion of the encapsulant to expose a top surface of the connector block; forming an interconnect layer electrically coupled to the top surface of the connector block; removing the temporary support structure to expose a bottom surface of the connector block; and electrically coupling a tangible element to the bottom surface of the connector block. 16. The method of claim 15, wherein electrically coupling a tangible element to the bottom surface of the connector block, comprises plating a conductive material to form an antenna. 17. The method of claim 16, wherein electrically coupling a tangible element to the bottom surface of the connector block further comprises: depositing a dielectric layer over the bottom surface of the connector block; and forming a via in the dielectric layer, wherein the via is electrically coupled to the connector block and the antenna. 18. The method of claim 15, wherein the removing a portion of the encapsulant to expose a top surface of the connector block comprises grinding the encapsulant. 19. The method of claim 15, wherein the temporary support structure is selected from a group consisting of a tape and a carrier. 20. The method of claim 15, wherein the connector block has at least two coaxial electrical paths.
|
<SOH> BACKGROUND <EOH>1. Field This disclosure relates generally to packages that have more than one element including at least one semiconductor device, and more specifically, to interconnect for such packages. 2. Related Art One technique for increasing density of functionality is to include multiple elements, such as integrated circuits into one package. This is an alternative to simply placing all of the functionality on a single integrated circuit because there are types of integrated circuits and semiconductor components that are difficult to make on the same integrated circuit or at least difficult to optimize on the same integrated circuit. Radio frequency (RF) circuits typically require a different process than logic. Also logic and analog may need to be optimized and use a different process. One of the techniques for placing multi-elements in the same package is redistributed chip package (RCP) which uses an organic fill around the elements and builds interconnect layers on a top side of the package where external contacts are also formed. This has been found to be a useful packaging technique which provides a very effective way of combining elements and connecting to them on a top side of the package. There is, however, further benefit for increased utility of RCP.
|
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>The present invention is illustrated by way of example and is not limited by the accompanying figures, in which like references indicate similar elements. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. FIG. 1 is a cross section of a packaged semiconductor device at a stage in processing according to an embodiment; FIG. 2 is a cross section of the packaged semiconductor device of FIG. 1 at a subsequent stage in processing; FIG. 3 is a cross section of the packaged semiconductor device of FIG. 2 at a subsequent stage in processing; FIG. 4 is a cross section of the packaged semiconductor device of FIG. 3 at a subsequent stage in processing; FIG. 5 is a cross section of the packaged semiconductor device of FIG. 4 at a subsequent stage in processing; FIG. 6 is a cross section of the packaged semiconductor device of FIG. 5 at a subsequent stage in processing; FIG. 7 is a cross section of the packaged semiconductor device of FIG. 6 at a subsequent stage in processing; FIG. 8 is a cross section of the packaged semiconductor device of FIG. 7 at a subsequent stage in processing; FIG. 9 is a cross section of the packaged semiconductor device of FIG. 8 at a subsequent stage in processing; FIG. 10 is a top view of a portion of the packaged device of FIGS. 1-9 ; and FIG. 11 is a top view of an alternative for the portion of FIG. 10 . detailed-description description="Detailed Description" end="lead"?
|
BACKGROUND 1. Field This disclosure relates generally to packages that have more than one element including at least one semiconductor device, and more specifically, to interconnect for such packages. 2. Related Art One technique for increasing density of functionality is to include multiple elements, such as integrated circuits into one package. This is an alternative to simply placing all of the functionality on a single integrated circuit because there are types of integrated circuits and semiconductor components that are difficult to make on the same integrated circuit or at least difficult to optimize on the same integrated circuit. Radio frequency (RF) circuits typically require a different process than logic. Also logic and analog may need to be optimized and use a different process. One of the techniques for placing multi-elements in the same package is redistributed chip package (RCP) which uses an organic fill around the elements and builds interconnect layers on a top side of the package where external contacts are also formed. This has been found to be a useful packaging technique which provides a very effective way of combining elements and connecting to them on a top side of the package. There is, however, further benefit for increased utility of RCP. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is illustrated by way of example and is not limited by the accompanying figures, in which like references indicate similar elements. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. FIG. 1 is a cross section of a packaged semiconductor device at a stage in processing according to an embodiment; FIG. 2 is a cross section of the packaged semiconductor device of FIG. 1 at a subsequent stage in processing; FIG. 3 is a cross section of the packaged semiconductor device of FIG. 2 at a subsequent stage in processing; FIG. 4 is a cross section of the packaged semiconductor device of FIG. 3 at a subsequent stage in processing; FIG. 5 is a cross section of the packaged semiconductor device of FIG. 4 at a subsequent stage in processing; FIG. 6 is a cross section of the packaged semiconductor device of FIG. 5 at a subsequent stage in processing; FIG. 7 is a cross section of the packaged semiconductor device of FIG. 6 at a subsequent stage in processing; FIG. 8 is a cross section of the packaged semiconductor device of FIG. 7 at a subsequent stage in processing; FIG. 9 is a cross section of the packaged semiconductor device of FIG. 8 at a subsequent stage in processing; FIG. 10 is a top view of a portion of the packaged device of FIGS. 1-9; and FIG. 11 is a top view of an alternative for the portion of FIG. 10. DETAILED DESCRIPTION An RCP is built having multiple elements that are interconnected with external connections available on a top side. One of the elements is a connection block which provides the capability of extending from the top side to a back side because the connection block is prefabricated. The connection block, which can also be called a connector block, has the organic fill formed around in the same manner as the other elements in the RCP. The connection block thus allows electrical connection to be made from the interconnect on the top side to the back side without having to etch via holes and then filling the via holes to form vias. The distance from the top side to the back side, for practical production, is too long for forming and filling vias. One application of connection block is to place an antenna on the back side. Another is place a ground plane on the back side. This is better understood by reference to the drawings and the following description. Shown in FIG. 1 is a package 10 comprising a carrier 12, a tape 14, an element 16, an element 18, and connection block 20. Carrier 12 is for providing mechanical support. Tape 14 is two-sided. Element 16 may be an integrated circuit, and element 18 may be an integrated circuit. On or the other could also be another type of element such as a passive device or a discrete semiconductor device. Connection block 20 has a conductor 22, a conductor 24, and a conductor 26 that run vertically the length connection block 20 and are surrounded by a dielectric 28. Dielectric 28 is preferably an organic material similar to or the same as that used as the fill in making an RCP, but dielectric 28 could also be another material such as ceramic. Copper is a preferred material for conductors 22, 24, and 26 because of its relatively high conductivity and relatively low cost. More conductive material such as platinum, gold, or silver may be used but at a higher cost. The length of connection block 20 is chosen to be a little thicker than the thickness of the organic layer that surround the elements of the finished RCP. A common thickness for the organic layer surrounding the elements is about 0.65 millimeter (mm) but this may vary. In such case of 0.65 mm, connection block 20 and thus conductors 22, 24, and 26 are about 0.70 mm in length. Connection block 20 is preferably one mm or more in diameter. A smaller diameter may present difficulties in adhering reliably to tape 14 but may nonetheless be advantageous for some applications. Shown in FIG. 2 is package 10 after deposition of an organic layer 30 which covers elements 16 and 18 and connection block 20. Organic layer 30 may be deposited to be about 0.80 mm for the example of connection block 20 being about 0.70 mm. Organic layer 30 may be considered a polymer layer. Shown in FIG. 3 is package 10 after grinding organic layer 30 and a small portion of connection block 20 to expose conductors 22, 24, and 26. Organic layer 30 is then reduced, in this example, to 0.65 mm. Shown in FIG. 4 is package 10 after removing carrier 12 and tape 14. FIG. 4 also has package 10 inverted from that of FIGS. 1-3. Elements 16 and 18 are exposed on the top side of package 10. The exposed surface of element 16 and the expose surface of element 18 are where contacts for elements 16 and 18 reside. Shown in FIG. 5 is package 10 after forming an interconnect 32 in contact with connection block 20, element 16, and element 18. Interconnect 32 may be made of multiple conductive layers connected to elements 16 and 18 and connection block 20 using vias. On interconnect 32 is a plurality of pads 34 of which one is pad 36. Pads 34 are for receiving solder balls and are on a top side of package 10. Connection block 20 is exposed on a back side of package 10. In a conventional RCP which would not have connection block 20, processing could be complete except for the solder balls. Solder balls could be added at this point or at a subsequent convenient time. Shown in FIG. 6 is package 10 after forming a dielectric layer 38 on the back side and forming vias 42, 44, and 46 through dielectric layer 38. Dielectric layer 38 is preferably the same material as organic layer 30 but could be another insulating material. Dielectric layer 38 may be 0.1 mm thick. Via 42 is in contact with conductor 22. Via 44 is contact with conductor 24. Via 46 is in contact with conductor 46. FIG. 6 also shows package 10 inverted from FIGS. 4 and 5. The side with pads 34 is still called the top side though and the side with dielectric layer 38 is still called the back side. Shown in FIG. 7 is package 10 after forming a patterned conductive layer over dielectric layer 38 comprising a ground plane 47 in contact with via 40, a trace 48 on in contact with via 42, and a trace 50 in contact with via 44. Ground plane 47 surrounds traces 48 and 50. Trace 48 extends laterally from via 42 and is present for stability. Similarly, trace 50 extends laterally from via 44 in a different direction from that of trace 48 so that the lateral extension is not visible in the cross section of FIG. 7. The patterned conductive layer may be made by a conventional plating process in which a thin seed layer is deposited followed by photoresist which is patterned. Plating then ensues so that the conductive material, preferably copper although other metals may also be effective, grows in the areas not covered by the photoresist. The photoresist is removed. An etch back is performed to remove the seed layer in the areas where the conductive layer was not grown. The thickness of ground plane 47 and traces 48 and 50 may be about 0.10 mm. Shown in FIG. 8 is package 10 after forming a dielectric layer 52 and vias 54 and 56 through dielectric layer 52. Dielectric layer 52 may be the same material as for dielectric layer 38. Via 54 is in contact with trace 48. Via 56 is contact with trace 50. Although via 56 is shown in the cross section of FIG. 8 in contact with trace 50, via 56 is preferably located over a wider portion of trace 50 than shown. Shown in FIG. 9 is package 10 after forming an antenna 58 in contact with vias 54 and 56. Antenna 58 may be formed and patterned using the same plating technique described for ground plane 47 and traces 48 and 50. Antenna 58 may be 0.200 mm thick. With antenna 58 in contact with vias 54 and 56, antenna is coupled to conductors 22 and 24, respectively. Due to the high frequencies that may be involved, vias 54 and 56 may not have to be in actual contact with antenna 58, if sufficiently close to antenna 58, for antenna 58 to be coupled to conductor 22. Package 10 of FIG. 9 is a completed RCP that will have solder balls added later at a time closer to being mounted on a circuit board. Shown in FIG. 10 is a top view of connection block 20 showing conductors 22, 24, and 26 in a line and dielectric 28 surrounding them in a circular shape. In this configuration, connection block 20 is a cylinder with three inline conductors. Conductors 22, 24, and 26 could be in a different configuration. Also the shape could be different than circular, such as square, rectangular, or triangular. Shown in FIG. 11 is an alternative connection block 60 comprising an outer insulating layer 68, a conductor ring 62, an inner conductor 64, and an insulating layer between conductor ring 62 and inner conductor 64. This forms a coaxial line which may be particularly beneficial when coupling to an antenna that is transmitting and receiving RF. Connection block 60 may replace connection block 20 with respect to the connection to antenna 58. If a ground plane were still desirable, the connection to the ground plane could be by another connection block or connection block 60 could be modified to have another conductor outside ring 62 for coupling to the ground plane. Construction of a connection block such as connection block 20 or connection block 60 may be achieved using wire bond machines. A wire bond is commonly 25 microns in diameter. Three of those wire bonds can be placed into a cylindrical mold that is many times longer than that of connection block 20. The mold is filled with the desired dielectric such as the material used for dielectric 30. The resulting structure is then cut into pieces of the desired length of about 0.070 mm. Instead of an organic material, the surrounding dielectric may be a material such as ceramic. The rigidity of ceramic may be beneficial in the manufacturing process. By now it should be appreciated that there has been provided a packaged semiconductor device having an interconnect layer, a semiconductor device, a first conductive element, and a connector block. The interconnect layer is over a first side of a polymer layer. The semiconductor device is surrounded on at least three sides by the polymer layer and is coupled to the interconnect layer. The first conductive element is over a second side of the polymer layer. The second side is opposite the first side. The connector block is within the polymer layer and has at least one electrical path extending from a first surface of the connector block to a second surface of the connector block, and electrically couples the interconnect layer to the first conductive element through the at least one electrical path. The connector block may comprise an insulating material surrounding the at least one electrical path. The connector block may have at least two coaxial electrical paths. The at least one electrical path may be a ground path and the first conductive element may be a ground plane. The at least one electrical path may be a signal path and the first conductive element may be an antenna. The packaged semiconductor device may further comprise a second conductive element and a second electrical path, wherein the second electrical path is a ground path and the second conductive element is a ground plane. The packaged semiconductor device may further comprise a third electrical path, wherein the third electrical path is coupled to the antenna. Also provided is a method for forming a packaged semiconductor device. The method includes surrounding a semiconductor device on at least three sides by a polymer layer. The method further includes forming an interconnect layer over a first side of the polymer layer and over the semiconductor device, wherein the semiconductor device is coupled to the interconnect layer. The method further includes forming a conductive element over a second side of the polymer layer, wherein the second side is opposite the first side. The method further includes electrically coupling the interconnect layer to the conductive element through a connector block within the polymer layer, having at least one electrical path. The forming the conductive element over a second side may comprise plating a conductive material to form an antenna. The step of surrounding may comprise attaching a semiconductor device to a temporary support structure, forming the polymer layer over the semiconductor device, and removing the temporary support structure after forming the polymer layer. The step of electrically coupling may comprise attaching the connector block to the temporary support structure before forming the polymer layer, removing a portion of the polymer layer to expose a surface of the connector block, forming the interconnect layer over the surface of the connector block while forming the interconnect layer over the first side of the polymer layer. The method may further comprise depositing a dielectric layer over the surface of the connector block, and forming a via in the dielectric layer, wherein the via is electrically coupled to the connector block and the conductive element. The at least one electrical path may be selected from the group consisting of a ground path and a signal path. The first conductive element may be selected from a group consisting of a ground plane and an antenna. The at least one electrical path may comprise at least two coaxial electrical paths. Further described is a method for forming a packaged semiconductor device. The method includes attaching a semiconductor device to a temporary support structure. The method further includes attaching a connector block to the temporary support structure, wherein the connector block has at least one electrical path. The method further includes forming an encapsulant over the connector block and the semiconductor device. The method further includes removing a portion of the encapsulant to expose a top surface of the connector block. The method further includes forming an interconnect layer electrically coupled to the top surface of the connector block. The method further includes removing the temporary support structure to expose a bottom surface of the connector block. The method further includes electrically coupling a tangible element to the bottom surface of the connector block. The step of electrically coupling a tangible element to the bottom surface of the connector block may comprise plating a conductive material to form an antenna. The step of electrically coupling a tangible element to the bottom surface of the connector block may further comprise depositing a dielectric layer over the bottom surface of the connector block, and forming a via in the dielectric layer, wherein the via is electrically coupled to the connector block and the antenna. The step of removing a portion of the encapsulant to expose a top surface of the connector block may comprise grinding the encapsulant. The temporary support structure may be selected from a group consisting of a tape and a carrier. The connector block may have at least two coaxial electrical paths. Moreover, the terms “front,” “back,” “top,” “bottom,” “over,” “under” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. Although the invention is described herein with reference to specific embodiments, various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. For example, dielectric layer 38 is shown as being formed after interconnect layer 32 whereas dielectric layer 38 may be deposited before interconnect layer 32 is formed. Also plating was described as the method for forming patterned metal layers, but other deposition techniques may be used. For example, the metal could be sputtered and then patterned with an etch. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. Any benefits, advantages, or solutions to problems that are described herein with regard to specific embodiments are not intended to be construed as a critical, required, or essential feature or element of any or all the claims. The term “coupled,” as used herein, is not intended to be limited to a direct coupling or a mechanical coupling. Furthermore, the terms “a” or “an,” as used herein, are defined as one or more than one. Also, the use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed to imply that the introduction of another claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an.” The same holds true for the use of definite articles. Unless stated otherwise, terms such as “first” and “second” are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements.
|
H
|
H01
|
H01L
|
23
|
48
|
|||
11987866
|
US20090318186A1-20091224
|
Add-on for a communicating terminal comprising imaging means and assembly comprising the add-on and the communicating terminal
|
ACCEPTED
|
20091210
|
20091224
|
[]
|
H04M100
|
["H04M100", "H04N5222"]
|
7995140
|
20071205
|
20110809
|
348
|
375000
|
69867.0
|
VU
|
NGOC YEN
|
[{"inventor_name_last": "Boutant", "inventor_name_first": "Yann", "inventor_city": "Chindrieux", "inventor_state": "", "inventor_country": "FR"}]
|
An accessory for a portable communicating terminal (T) fitted out with means (C) for processing and acquiring images through at least one optical system (O), an accessory comprising: means (4) for attachment onto the communicating terminal (T), an acquisition window (5) intended to be placed in relationship with the optical system (O) of the communicating terminal (T), illumination means (10) adapted for illuminating an acquisition region included in the field of acquisition of the optical system through the acquisition window (5), means (12) for powering the illumination means, and means (14) for controlling the illumination means.
|
1. An accessory for a portable communicating terminal (T) fitted out with means (C) for processing and acquiring images through at least one optical system (O), an accessory comprising: a means (4) for attachment onto the communicating terminal (T), an acquisition window (5) intended to be placed in relationship with the optical system (O) of the communicating terminal (T), illumination means (10) adapted so as to illuminate an acquisition region included in the field of acquisition of the optical system through the acquisition window (5), means (12) for powering the illumination means, and means (14) for controlling the illumination means. 2. The accessory according to claim 1, characterized in that the means (12) for powering the illumination means (10) comprise at least one accumulator (13) and/or one electric battery. 3. The accessory according to claim 1, characterized in that it comprises optical adjustment means (20) intended to cooperate with the optical system of the communicating terminal. 4. The accessory according to claim 3, characterized in that the optical adjustment means (20) have a variable focal distance. 5. The accessory according to claim 3, characterized in that the optical adjustment means (20) comprise a lens with a variable focal length. 6. The accessory according to claim 1, characterized in that it comprises means (7,22) for pressing on a subject (S) which is to be the object of an acquisition through the acquisition window (5). 7. The accessory according to claim 1, characterized in that the acquisition window (5) is delimited by an acquisition tube or channel (6) a first end of which is intended to be placed in relationship with the optical system (O) and the second end of which is intended to be placed in relationship with a subject (S) which is to be the object of an acquisition. 8. The accessory according to claim 7, characterized in that the second end is associated with means (7) for pressing on the subject. 9. The accessory according to claim 1, characterized in that the illumination means (10) are adapted so as to emit light rays (15) towards the acquisition window and it that it comprises means (25) for interposing a subject (S) which is to be the object of an acquisition, between the illumination means (10) and the acquisition window (5). 10. The accessory according to claim 1, characterized in that the illumination means (10) comprise at least one light source (11) and means (21) for guiding (2) or diffusing light emitted by the light source. 11. The accessory according to claim 1, characterized in that the means (21) for guiding the light are adapted so as to emit light rays (12) illuminating the acquisition region along a direction substantially parallel to an optical Δ or a focal axis of the optical system (O) of the communicating terminal (T). 12. The accessory according to claim 1, characterized in that the means (21) for guiding the light are adapted so as to emit light rays (15) illuminating the acquisition region along a direction oblique or perpendicular to an optical axis Δ or a focal axis of the optical system (O) of the communicating terminal (T). 13. The accessory according to claim 1, characterized in that the illumination means (10) comprise at least one light source (11) selected from: ultraviolet sources, infrared sources, white light sources, colored visible light sources. 14. The accessory according to claim 1, characterized in that it comprises at least one source of laser or coherent light. 15. The accessory according to claim 1, characterized in that it comprises at least one interface (26) for connection to the communicating terminal (T). 16. The assembly formed with a portable communicating terminal (T) fitted out for means (C) for processing and acquiring images through at least one optical system (O) and with an accessory (1) according to any of claims 1 to 15 attached onto the communicating terminal (T) so that the acquisition window (5) is positioned in a relationship with the optical system (O) of the communicating terminal (T). 17. The assembly according to claim 16, characterized in that it is adapted in order to provide reading of a marking and/or the acquisition of geometrical and/or physical features on a subject placed at a distance from the optical system, of less than 50 mm, and preferably less than 30 mm. 18. The assembly according to claim 16, characterized in that it is adapted in order to provide reading of a marking and/or acquisition of geometrical and/or physical features on a subject placed at a distance from the optical system of less than 20 mm and, preferably between 5 and 20 mm.
|
The present invention relates to the technical field of accessories intended to be fitted on portable communicating terminals in order to make them suitable for applying specific functions. More particularly, the present invention relates to the accessories intended to be used in combination with portable communicating terminals fitted out with means for processing and acquiring images such as for example smart telephones, called <<smartphones>>, equipped with movie or still cameras or even personal electronic assistants, called <<PDAs>>, also fitted out with movie or still cameras. Such portable communication terminals are relatively inexpensive means for acquiring images which are generally considered as being of medium quality, or of even low quality, because of the resolution of the sensors used. However, in spite of this low quality reputation of the images obtained with the movie or still cameras integrated into mobile telephones or personal digital assistants, the merit of the inventors was to demonstrate that it was possible to obtain with these devices, images of sufficient quality in order to allow an analysis of the microscopic or submillimeter geometrical structure of materials or different products in order to be notably able to apply methods for extracting signatures or physical characteristics and methods for applying these signatures as described for example in the patent applications FR2866139, WO200578651, US20052622350, FR2870376. However, the still or movie cameras fitting out smart telephones or personal electronic assistants are generally designed for making portraits, photographs of landscapes or even photographs indoors, so that their optical system has a set focal distance with which good focusing may be obtained for distances of the order of one meter or larger than one meter. Now, such a focal distance is unsuitable for close shots or so-called macroscopic shots. Moreover, smart telephones or personal digital assistants fitted out with still cameras only very rarely comprise light sources adapted to photography and assuming that they are fitted out with them, these light sources consist of flashes adapted for illuminating relatively remote and totally unsuitable scenes for close shots. Thus, there has appeared the need of means for easily making smart telephones or digital assistants fitted out with image-shooting systems, movie or still cameras, usable for obtaining images of microscopic or submillimeter details of various products. In order to achieve this goal, the invention relates to an accessory for a portable communicating terminal fitted out with means for processing and acquiring images through at least one optical system, an accessory comprising: means for attachment onto the communicating terminal, an acquisition window intended to be placed in a relationship with the optical system of the communicating terminal, suitable illuminating means for illuminating an acquisition region included within the field of acquisition of the optical system through the acquisition window, means for powering the illuminating means, and means for controlling the illumination means. By applying such an accessory, in combination with the portable communicating terminal, it is possible de produce a suitable device in a simple way, in order to provide acquisitions of images, objects or subjects located in close proximity to the optical system and in the area covered by the illumination means. According to an embodiment feature of the accessory according to the invention, the means for powering the illuminating means comprise at least one accumulator and/or one electric battery. With this feature, it is possible to give a certain autonomy to the accessory which may then illuminate subjects which are to be subject to an acquisition without providing external power to the accessory and to thereby notably avoid having to pick up power on the battery of the communicating terminal. According to another feature of the invention, the accessory comprises optical adjustment means intended to cooperate with the optical system of the communicating terminal. Application of such optical adjustment means may notably prove to be necessary when the optical system of the communicating terminal is not adapted so as to provide focusing at a lower reduced distance, for example 100 mm. According to the invention, the optical adjustment means then have a set or variable focal distance. In the case of optical adjustment means with a variable focal distance, the optical adjustment means may comprise a lens with a variable focal length, for example as developed and marketed by Varioptic in the case of a lens without any mobile mechanical part or by PGS in the case of a lens with mechanical stress. In the case when the optical adjustment means have a variable focal distance, the adjustment of the focal distance may either be performed once and for all in the workshop for example before marketing the accessory, or on the contrary be performed during use at each image shot for example. In the latter case, the accessory according to the invention may be fitted out with means for automatically adjusting of the focal distance. In an alternative embodiment, the adjustment of the focal distance will be controlled by the portable communicating terminal fitted onto the accessory according to the invention. According to still another feature of the invention which aims at facilitating the acquisition operation with which a fixed distance between the subject and the optical system may be obtained during the whole acquisition sequence, the accessory comprises means for pressing onto a subject which has to be the object of an acquisition through the acquisition window. The pressing means may then have a fixed position or on the contrary an adjustable position allowing the distance between the optical system of the portable communicating terminal and the subject to be adjusted. According to another feature of the invention, the acquisition window is delimited by an acquisition tube or channel, a first end of which is intended to be placed in a relationship with the optical system and the second end of which is intended to be placed in a relationship with a subject which should be the object of an acquisition. With such an embodiment of the acquisition window, it is possible to define with the tube, one end of which is in a relationship with the optical system of the communicating terminal and the other one with the subject or the portion of the subject to be photographed or filmed, a sort of acquisition chamber providing better control of the illumination of the area of the subject which is to be the object of the acquisition. According to the invention, this illumination chamber is not necessarily sealed from external light, although it is also possible to provide means with which such a seal may be obtained, such as for example a gasket system which will press against the communicating terminal around its optical system on the one hand and a lip or a gasket intended to press against the surface of the subject on the other hand. According to a feature of the invention, the second end of the acquisition tube or channel is associated with means for pressing on the subject, these pressing means either providing or not a lightproof seal as this was stated above. The illumination means fitting out the accessory according to the invention may be made in any suitable way. Thus, the illumination means may emit light, for example point-like, diffuse light, or even simulate an annular light source. The illumination means may also emit light rays along different incidences or a combination of incidences. According to a feature of the invention, the illumination means are adapted in order to emit light rays towards the acquisition window and the accessory comprises means for interposing a subject which is to be the object of an acquisition, between the illumination means and the acquisition window. According to another feature of the invention, the illumination means comprise at least one light source and means for guiding or diffusing the light emitted by the light source. The means for guiding the light may then be adapted so as to emit light rays illuminating the acquisition region along a direction substantially parallel to an optical or focal axis of the optical system of the communicating terminal. The means for guiding the light may also be adapted so as to emit light rays illuminating the acquisition region along an oblique direction or perpendicular to an optical or focal axis of the optical system of the communicating terminal. Moreover, the light used for providing the illumination of the subject may be of different natures. Thus, according to a feature of the invention, the illumination means comprise at least one light source or a combination of light sources selected from: ultraviolet sources, infrared sources, white light sources, colored visible light sources. According to the invention, the light emitted by the illumination means may be coherent of the laser type, for example, or incoherent of the white light type for example, depending on the contemplated applications. Of course, the illumination means upon demand from the user or depending on controls received from the portable communicating terminal, may be adapted for emitting either coherent light or incoherent light or even to operate simultaneously as an incoherent light source, and an incoherent light source may for example have different wavelengths. According to another feature of the invention, the accessory comprises at least one interface for connection to the communicating terminal. Such a connection interface may for example be used so that the battery possibly fitting out the accessory according to the invention may power the portable communicating terminal. This interface may also be used in order to allow the communicating terminal to control the operation of the illumination means or further the focusing provided by the optical adaptation means of the accessory. Still according to a feature of the invention, the accessory comprises means for communicating with the portable communicating terminal. These communication means may then be optical, by wire or by radio. Like the connection interface, the communication means may be used in order to notably allow the communicating terminal to control the operation of the illumination means or further the focusing provided by the optical adaptation means of the accessory. The invention also relates to an assembly which comprises a portable communicating terminal fitted out with means for processing and acquiring images through at least one optical system, as well as an accessory according to the invention attached onto the communicating terminal so that the acquisition window is positioned in relationship with the optical system of the communicating terminal. According to a feature of the invention, this assembly is adapted so as to provide reading of markings on a subject and/or for providing acquisition of submillimeter physical and/or geometrical features of this subject placed at a distance from the optical system, of less than 50 mm and preferably less than 30 mm. According to another feature of the invention, the assembly is adapted so as to provide reading of a marking on a subject and/or acquisition of physical and/or geometrical features of this subject placed at a distance from the optical system of less than 20 mm and preferably between 5 mm and 20 mm. According to the invention, the term “marking” notably designates one or more signs printed on a subject such as for example a one-dimensional bar code, or a two-dimensional code such as a code of the datamatrix type. The term “marking” also designates one or more signs capable of being made at the surface or in the depth on a subject by various techniques such as for example etching or micro-etching, embossing, microperforation. Of course, the different aforementioned features of the invention may be applied with each other according to different combinations when they are not incompatible with or exclusive from each other. Moreover, various other characteristics of the invention will become apparent from the description made below, with reference to the appended drawings which show, as non-limiting examples, embodiments of the object of the invention. FIG. 1 is a schematic perspective view partly cut away from an assembly comprising an accessory according to the invention and a portable communicating terminal which is fitted out with means for processing and acquiring images through at least one optical system and which is fitted onto the accessory according to the invention. FIG. 2 is a schematic perspective view partly cut away from the accessory, illustrated in FIG. 1, alone. FIG. 3 is an example of a highly enlarged image from an acquisition of a region of a subject comprising a marking made on a fiber support such as paper or cardboard, this acquisition having been carried out by means of an assembly, as illustrated in FIG. 1, comprising an accessory according to the invention and a portable communicating terminal. FIG. 4 is a longitudinal schematic sectional view showing an alternative embodiment of the accessory according to the invention in association with a portable communicating terminal. FIG. 5 is a schematic sectional view similar to FIG. 4 showing another alternative embodiment of the accessory according to the invention in association with a portable communicating terminal. An accessory, according to the invention, such as schematically illustrated in FIG. 1 and designated on the whole by reference 1, is intended to be used in association with a portable communicating terminal T fitted out with means for processing and acquiring images C through an optical system O. The means for processing and acquiring images C comprise for example one or more sensors of the CCD, CMOS type or the like connected to the processing and/or computing unit. In the sense of the invention, a portable communicating terminal fitted out with means for processing and acquiring images notably corresponds to a smart telephone integrating a still or movie camera or even a personal digital assistant also integrating a still or movie camera. The accessory 1 according to the invention comprises a body 2 which comprises, according to the illustrated example and as this is more particularly apparent from FIG. 2, a face for receiving 3 the portable communicating terminal T. The receiving face 3 is then associated with means 4 for attachment of the body 2 onto the terminal T. According to the invention, the attachment means 4 may be made in any suitable way and, according to the illustrated example, attachment means 4 are formed by curved rigid tabs which define in a relationship with the body 2 and its receiving face 3, a housing for receiving the terminal T. In order to allow application of image acquisition means C of the terminal T, an acquisition window 5 is provided in the body 2 and placed so as to be facing the optical system O of the terminal T when the accessory 1 is attached on the latter as shown by FIG. 1L. According to the illustrated example, the acquisition window 5 is delimited by an acquisition tube or channel 6 provided in the body 2 and emerging at a face 7 of the body 2 opposite to the receiving face 3. The face 7 then forms a means for pressing on a subject S such as for example a product which is to be the object of an authentication operation. The accessory 1 further comprises adapted illumination means 10 so as to illuminate an acquisition region R included in the acquisition field of the optical system O through the acquisition window 5. The illumination means 10 may be made in any suitable way and for example comprise at least one light source 11 which, according to the example, is placed at one of the walls of the acquisition channel 6 so as to emit light rays 15 which have an oblique direction or perpendicular to the optical axis A of the optical system O. The nature of the light emitted by the smooth source will be selected depending on the application, thus the use of a light source for example selected from: ultraviolet sources, infrared sources, white light sources, colored visible light sources, may be contemplated The light source may also emit coherent light or incoherent light as selected depending on the applications. As a light source, the use of a laser may also be contemplated. The power required for operating the illuminating means 10 is provided by power supply means 12 which will advantageously comprise at least one electric accumulator 13, preferably a rechargeable accumulator. The accessory according to the invention also comprises means 14 for controlling the illuminating means 10. The thereby formed accessory according to the invention is therefore intended to be fitted on the portable communicating terminal T so as to form an assembly particularly suitable for close image shots of at least a portion of the surface of the subject S. For this purpose, the aperture of the acquisition channel 6 located at the face 7 is placed in contact with the subject S. The body 2 and the channel 6 are then designed so that the distance d between the optical system O and the subject S is less than 50 mm and preferably less than 30 mm. In a more particularly preferred embodiment, the pressing means formed by the face 7 are designed so that the distance is less than 20 mm and preferably between 5 mm and 20 mm. If the optical system O fitting out the terminal T is not adapted so as to allow focusing at such a reduced distance, the accessory according to the invention will then comprise optical adjustment means 20 intended to cooperate with the optical system O so that the image processing and acquisition C may obtain at least one image of the surface of the subject S. The optical adjustment means 20 may be made in any suitable way and for example comprise a lens of set focal length correcting the minimum focusing distance of the optical system O. Of course, the adjustment means 20 may also comprise a set of lenses in order to form either a system with a set focal distance or a system with a variable focal length. When an image needs to be made of the surface of the subject S, the user switches on the illuminating means 10 via control means 14. The user may then trigger at the terminal T a sequence for acquiring or taking shots. It should be noted that the acquisition channel 6 then forms in combination with terminal T and the subject S a sort of acquisition chamber allowing optimum illumination conditions by the means 10 for illuminating the surface of the subject S to the extent that even if the acquisition chamber is not perfectly sealed to external light, it limits the perturbations therefrom. The screen E of the terminal T may be used for previewing the region observable by the acquisition means C so as to place the window 6 in relationship with the region of interest R which may for example comprise a marking M printed on a fiber support as this is illustrated in FIG. 3. According to the contemplated applications, the terminal T may be adapted for example in order to provide certain or the whole of the following operations after acquisition or shooting. The terminal T may for example decode the marking M in order to extract information from it which may be used in a subsequent process. The accessory 1/terminal T assembly according to the invention having a certain capability of magnifying the marking M, may then be made so as to be included in a square with a side less than 10 mm or even 5 mm so that it is impossible to distinguish with the naked eye, and at a distance of about 30 cm, the black areas from the white areas which compose it. The information of the marking M may then be used for comparison with information from a database recorded in the terminal T for example in order to proceed with an identification or establishment of a relationship. If the terminal T integrates the functionalities for communication and connection to a communications network and to an external computer system, the information from the marking M may be transmitted via the network to the external computer system. It is also possible to send via the network, the acquired raw image, without any prior processing aiming at extracting information or a signature from it, to the external computer system. If the terminal T integrates GPS and/or time stamping type localization functionalities, the raw acquisition and/or the information extracted from the acquisition may be associated with the geographical coordinates or the acquisition location and/or with the acquisition date and time. Within the scope of an application aiming at providing authentication of objects, the terminal T may for example be adapted in order to extract from the acquisition both information contained in the marking and a digital signature from the material bearing the marking. The information and the signature may then be compared with information and signatures stored in a database recorded in the terminal T or in a remote database. The present signatures in such databases may then have been extracted either by a system distinct from the accessory/terminal assembly according to the invention such as an industrial system, or on the contrary by an analogous system or by a system identical to the assembly according to the invention or even by the same assembly. Within the scope of certain applications, the accessory/terminal assembly may be used for extracting from a given subject a digital signature related to the random character of the geometry of its structure observed at submillimeter scale. This signature may then be transmitted to an external system which may identify the subject when the latter will be presented to it by for example comparing the received signature with a new extracted signature. Within the scope of an authentication application, for example involving a marking containing information coded by means of an encryption key formed by a digital signature extracted from the structure of the support of the marking, the accessory/terminal assembly may be adapted in order to provide by itself, reading of the marking, extraction of the signature from the support and decoding of the information of the marking by means of the key formed by the digital signature. The nature of the decoded information will then certify the authenticity of the support. Of course, the accessory/terminal assembly according to the invention may also be adapted so as to provide all or part of the processes or operations described in the applications FR 2 866 139, WO2005/78651, US20052622350, FR 2 870 376, FR 05 13231 and FR 06 01342 incorporated herein by reference. Moreover, it is possible to contemplate various alternatives of the accessory depending on the use which will be made of the assembly formed by the accessory 1 and the portable communicating portable T which it fits out. Thus, FIG. 4 shows an alternative embodiment of the accessory 1 according to which the illumination means 10 comprise means 21 for guiding and diffusing light emitted by the light source 11. According to the illustrated example, the light guiding means comprise a semi-transparent mirror 21 placed so that the light rays 15 emitted by the source 11 arrive on the surface of the subject S with a direction substantially parallel to the axis Δ of the optical system O. According to this alternative embodiment, the accessory further comprises legs 22 as means pressing on the subject S. Further, in order to allow communication between the accessory 1 and the terminal T, the accessory is also fitted out with communication means 23 such as for example a WIFI or Bluetooth® radio communications interface. It may also be contemplated that the communications means 23 operate with infrared. FIG. 5 illustrates another alternative embodiment of the accessory 1 according to which the illumination means 10 are adapted so as to emit light rays towards the acquisition window and more particularly towards the optical system O. For this purpose and, according to the illustrated example, the illumination means comprise suitable guiding means 21 in order to send back parallel to the axis Δ, and towards the optical system O, the light rays 15 emitted by the source 11 perpendicularly to the axis Δ. The accessory 1 then comprises means 25, such as for example, a hatch or a slot, for interposing a subject S between the illumination means 10 and the acquisition window or the optical system O. Such a configuration allows one to proceed with acquisition by transmission or transparence of the subject S which may for example be a sheet of paper. According to this example, the accessory also comprises an interface 26 for connection to the communicating terminal T. This connection interface 26 may then have various functions and, for example, allow the accumulator 13 to power the communicating terminal T or, conversely allow the communicating terminal to power the illumination means 10. According to the alternative illustrated in FIG. 5, the accessory 1 does not comprise any optical adaptation means. However, the accessory 1 may be fitted out with the latter, and in the event of optical adaptation means with a variable focal length, the connection interface may be adapted so as to allow the terminal T to control the optical adaptation means so as to provide the required focusing for perfect acquisition. Of course, various other modifications may be made to the accessory for a portable communicating terminal without departing from the scope of the present invention.
|
H
|
H04
|
H04M
|
1
|
00
|
|||||
11821038
|
US20080077086A1-20080327
|
Tamper-proof injector or applicator for dispensing a liquid or pasty drug
|
ACCEPTED
|
20080312
|
20080327
|
[]
|
A61M550
|
["A61M550"]
|
8696624
|
20070621
|
20140415
|
604
|
110000
|
91661.0
|
HOLLOWAY
|
IAN
|
[{"inventor_name_last": "Lonien", "inventor_name_first": "Birgit", "inventor_city": "Dudeldorf", "inventor_state": "", "inventor_country": "DE"}, {"inventor_name_last": "Mohs", "inventor_name_first": "Sascha", "inventor_city": "Dudeldorf", "inventor_state": "", "inventor_country": "DE"}]
|
An injector or applicator is used for dispensing a liquid or pasty drug. It comprises an injector body (1), a piston body (2) and a closing cap (3). The closing cap (3) has a cap portion and a connecting portion. The cap portion is used for closing the opening of the injector or applicator. The connecting portion is used for connecting the closing cap (3) with the injector or applicator. The cap portion and the connecting portion are releasably connected by a tear edge. To create an improved tamper-proof feature, the housing portion (1) has an undercut, and the piston body (2) has a protrusion (FIG. 6).
|
1. An injector or applicator for dispensing a liquid or pasty drug, comprising a housing portion (1), a piston body (2), and a closing cap (3) with a cap portion (10) for closing the opening (8) of the injector or applicator and connecting portion (9) for connecting the closing cap (3) with the injector or applicator, the cap portion (10) and the connecting portion (9) being releasably connected by a tear edge (19), wherein the housing portion (1) has an undercut (18) and the piston body (2) has a protrusion. 2. The injector or applicator according to claim 1, wherein the housing portion (1) has one or more lamellae and/or hooks. 3. The injector or applicator according to claim 1, wherein the piston body (2) is made of one piece. 4. The injector or applicator according to claim 1, wherein the piston body (2) comprises a plunger (15) and a piston (16) which is releasably connected with the plunger (15). 5. The injector or applicator according to claim 1, wherein the plunger (15) and the piston (16) are connected with each other by a sealing tape and/or by a predetermined breaking point. 6. The injector or applicator according to claim 1, wherein the connecting portion (9) has a clamping portion. 7. The injector or applicator according to claim 1, wherein the connecting portion (9) has a bead (11). 8. The injector or applicator according to claim 1, wherein the connecting portion (9) is pressed into the injector or applicator. 9. The injector or applicator according to claim 1, wherein the connecting portion (9) is welded to the injector or applicator (20, 21). 10. The injector or applicator according to claim 1, wherein the connecting portion (9) is positively connected with the injector or applicator. 11. The injector or applicator according to claim 1, wherein the tear edge (19) connecting the cap portion (10) and the connecting portion (9) extends in radial direction. 12. The injector or applicator according to claim 1, wherein the cap portion (10) has a sealing pin (13). 13. The injector or applicator according to claim 2, wherein the piston body (2) is made of one piece. 14. The injector or applicator according to claim 13, wherein the piston body (2) comprises a plunger (15) and a piston (16) which is releasably connected with the plunger (15). 15. The injector or applicator according to claim 2, wherein the piston body (2) comprises a plunger (15) and a piston (16) which is releasably connected with the plunger (15). 16. The injector or applicator according to claim 3, wherein the piston body (2) comprises a plunger (15) and a piston (16) which is releasably connected with the plunger (15). 17. The injector or applicator according to claim 16, wherein the plunger (15) and the piston (16) are connected with each other by a sealing tape and/or by a predetermined breaking point. 18. The injector or applicator according to claim 2, wherein the plunger (15) and the piston (16) are connected with each other by a sealing tape and/or by a predetermined breaking point. 19. The injector or applicator according to claim 3, wherein the plunger (15) and the piston (16) are connected with each other by a sealing tape and/or by a predetermined breaking point. 20. The injector or applicator according to claim 4, wherein the plunger (15) and the piston (16) are connected with each other by a sealing tape and/or by a predetermined breaking point.
|
This invention relates to a tamper-proof injector or applicator for dispensing a liquid or pasty drug according to the generic part of claim 1. The injector or applicator is used in particular for dispensing a drug for the medical treatment of an animal, in particular for the medical treatment of the udder of an animal. In addition, the invention can be applied to any known form of administration (oral, nasal, etc.). An injector according to the generic part of claim 1 is known from EP 1 477 128 A1. The injector includes a housing portion, a piston body and a closing cap. The closing cap comprises a cap portion for closing the opening of the injector and a connecting portion for connecting the closing cap with the injector. The cap portion and the connecting portion are releasably connected by a tear edge. This should create a tamper-proof feature. However, the injector according to EP 1 477 128 A1 merely prevents a manipulation in the vicinity of the cap. Manipulations in the vicinity of the piston are not excluded. Proceeding therefrom, it is the object underlying the invention to propose an injector or applicator as mentioned above with an improved tamper-proof feature. In accordance with the invention, this object is solved by the characterizing features of claim 1. The housing portion has an undercut. The piston body has a protrusion. The undercut and the protrusion are adjusted to each other such that the piston body or a part thereof cannot be withdrawn from the housing portion. The piston body or a part thereof are retained at the undercut when trying to withdraw the same from the housing portion. In accordance with the invention, the piston body thus is secured against withdrawal from the housing portion. An exchange or manipulation of the liquid or paste present in the housing portion, which requires a complete withdrawal of the piston body from the housing portion, is not possible. This can also prevent manipulations in the vicinity of the piston. The invention creates an improved tamper-proof feature for an injector or applicator for dispensing a liquid or pasty drug. The injector or applicator of the invention is designed to be tamper-proof or tamper-evident. Advantageous developments are described in the sub-claims. The housing portion can include one or more lamellae and/or one or more hooks. The lamellae and/or hooks are shaped such that they form an undercut and prevent withdrawal of the piston body from the housing portion. The piston body can be made of one piece. For this purpose, the piston body can be formed integrally. It is, however, also possible to compose the piston body of two or more individual parts, these parts being non-releasably connected with each other. When the plunger and the piston are made of one piece, or when the plunger and the piston are made of two pieces, but are so firmly connected with each other that they cannot be separated from each other, it is achieved by means of this locking or undercut or by means of the lamellae or hooks that the entire piston body cannot be withdrawn from the housing portion. In accordance with a further advantageous development, the piston body comprises a plunger and a piston which is releasably connected with the plunger. In this case, the protrusion of the piston body is formed by the piston. When the piston body is withdrawn from the housing portion, the piston abuts against the undercut of the housing portion. If then an attempt is made to withdraw the piston body from the housing portion by force, the piston gets stuck at the undercut. The plunger and the piston are connected with each other such that in this case the piston is separated from the plunger, so that the plunger can completely be withdrawn from the housing portion, but the piston remains in the housing portion, where it forms a tamper-proof feature and prevents a manipulation of the liquid or pasty drug present in the piston body. When the piston body comprises a plunger and a piston, which are releasably connected with each other, the plunger and the piston can be made of one piece or of two pieces. In particular, the plunger and the piston can be connected with each other by a predetermined breaking point. Instead of a predetermined breaking point or in addition to the same, the plunger and the piston can be connected with each other by a sealing tape. Advantageously, the connecting portion includes a clamping portion. The connecting portion thereby can be clamped to the injector or applicator. Preferably, the connecting portion or clamping portion has a bead. The bead preferably is shaped such that it engages behind a corresponding cavity provided in the injector or applicator, in particular behind a groove. In accordance with a further advantageous development, the connecting portion is pressed into the injector or applicator. In particular, the connecting portion can be frictionally connected with the injector or applicator. Thereby, it can be ensured in a simple way that the connecting portion remains connected with the injector or applicator when the cap portion is detached or torn off. In accordance with a further advantageous development, the connecting portion is welded to the injector or applicator. A further advantageous development is characterized in that the connecting portion is positively connected with the injector or applicator. The tear edge, which connects the cap portion and the connecting portion, preferably extends in radial direction. Advantageously, the cap portion has a sealing pin. The sealing pin preferably is shaped such that it engages in the opening of the tip of the housing portion and sealingly closes the same, when the closing cap is connected with the injector or applicator and the cap portion is not yet detached from the connecting portion. One embodiment of the invention will subsequently be explained in detail with reference to the attached drawing, in which: FIG. 1 shows an injector with attached closing cap in a sectional side view, FIGS. 1a, b, c, show enlarged partial views of FIG. 1, FIG. 2 shows the upper end of the injector and the closing cap in an enlarged representation, FIG. 2a shows an enlarged partial view of FIG. 2, FIG. 3 shows the closing cap upon detachment of the cap portion, FIG. 4 shows the injector with a one-piece piston body, which is partly withdrawn from the housing portion, FIG. 5 shows the injector with a piston body, which comprises a plunger and a piston and is partly withdrawn from the housing portion, FIG. 6 shows the injector of FIG. 5 with fully withdrawn plunger, and FIG. 7 shows the rear part of the housing portion in an enlarged representation. The injector 4 shown in the drawing, which can also be referred to as injection syringe, comprises a housing portion 1 and a piston body 2 which is longitudinally movable therein. At the front end of the housing portion 1, a tip 5 is provided, which is integrally formed with the housing portion 1. Inside the tip 5, a channel 6 is located, which is connected with the cavity 7 between the piston body 2 and the housing portion 1 and which opens into an opening 8 at the outer end of the tip 5. As shown in particular in FIGS. 1, 2 and 3, the closing cap 3 comprises a connecting portion 9 and a cap portion 10. At its lower end, the connecting portion 9 has a circumferential bead 11, which engages behind a corresponding groove 12 in the housing portion 1. The groove 12 is provided in the vicinity of the front end of the housing portion 1 on the outside thereof. It extends around the tip 5 in its base portion. In the embodiment shown in FIG. 1a, the bead 11 is frictionally connected with the groove 12. In its cross-section, the groove 12 is closed over a region of more than 180°, so that the bead 11 is retained therein. The cross-section of the groove 12 extends substantially U-shaped. The radially outer leg of the U-shaped profile of the groove 12 linearly extends in upward direction. In its upper end portion, the radially inner leg includes a bevel which extends towards the middle of the groove 12. The angle of this bevel is 15 to 45°. The adjoining region of the connecting portion 9 extends at an angle of 5 to 15° away from the groove 12. The bead 11 extends complementary to the groove 12. It is introduced into the groove 12 and clamped to or pressed into the groove, whereby the connecting portion 9 is firmly fixed on the housing portion 1. In the variant shown in FIG. 1b, the bead 11 is welded to the connecting portion 9. The first weld 20 is located at the base of the groove 12. The second weld 21 is located at the upper end of the outer leg of the U-shaped profile of the groove 12. It is possible to provide both welds 20, 21 or only one thereof. Moreover, the shapes of the bead 11 and of the groove 12 in the embodiment of FIG. 1b correspond to the shape as shown in FIG. 1a. The welds 20 and/or 21 can be provided in addition to the frictional connection as shown in FIG. 1a. However, it is also possible that the connecting forces are effected mostly or exclusively by one or both welds 20, 21. Furthermore, an undercut of the bead 11 in the groove 12 can be omitted in the case of one or more welds 20, 21. In the embodiment as shown in FIG. 1c, the bead 11 is positively connected with the groove 12. Here, the angle of the bevel is not 15 to 45°, as in FIG. 1a, but 90°. The cap portion 10 has a sealing pin 13, which is located inside the upper terminal region of the cap portion 10 and is directed downwards. When the closing cap 3 is connected with the housing portion 1, the sealing pin 13 engages in the opening 8 of the tip 5 of the housing portion 1, as can be taken in particular from FIG. 2. The opening 8 is sealingly closed by the sealing pin 13. The connecting portion 9 and the cap portion 10 are connected with each other by a tear edge 19. The tear edge is formed by a circumferential ring portion of small cross-section. It connects the upper terminal region of the connecting portion 9 with the lower terminal region of the cap portion 10. Connecting portion 9, cap portion 10 and tear edge 19 are formed integrally. As can be taken in particular from FIG. 2a, the tear edge 19 extends in radial direction. In the profile representation shown in FIG. 3, the outer profile edge 22 of the cap portion 10 radially extends further on the inside than the inner edge 23 of the connecting portion 9. The resulting offset a is bridged by the horizontally extending tear edge 19. The limits of the tear edge 19, which are horizontal as seen in profile, extend in parallel. The tear edge 19 constitutes a narrow web. As compared to the tear edge according to EP 1 477 128 A1, it has a simpler design saving more material. When the injector should be used for dispensing the liquid or paste present in the cavity 7, the cap portion 10 must be removed. This is effected in that the cap portion 10 is torn off. In doing so, the cap portion 10 is detached from the connecting portion 9 in the vicinity of the tear edge 19. The cap portion 10 can be removed in upward direction, as shown in FIG. 3, so that the tip 5 is exposed. Since the bead 11 is clamped or pressed into the groove 12, the connecting portion 9 remains connected with the housing portion 1. As a result, it is impossible to insert a further, undamaged closing cap 3 into the groove 12 of the housing portion 1. The connecting portion 9, which remains firmly connected with the housing portion 1, thus forms a tamper-proof feature. In the embodiment shown in FIGS. 5 and 6, the piston body 2 consists of a plunger 15, which protrudes from the housing portion 1 on the rear, and of a piston 16, which faces the front part of the housing portion 1. The cavity 7 is enclosed by the housing portion 1 and by the front end face of the piston 16. Plunger 15 and piston 16 are connected with each other by a slight frictional connection. For this purpose, the plunger 15 has an elevation 17 at its front end, which engages in a corresponding depression on the back of the piston 16, where the plunger 15 and the piston 16 are clamped to each other. In the vicinity of its rear end, the housing portion 1 has an undercut 18. The undercut 18 is formed by a step facing to the inside. This step can be formed to be circumferential. However, a plurality of steps can also be distributed around the periphery. The inside diameter of the housing portion 1 or the distance of opposed steps is smaller in the rear part of the housing portion 1 than in the part located further to the front. Furthermore, this diameter or these distances is/are adjusted to the piston 16 such that this piston 16 can be moved into the housing portion 1, but can no longer be moved out of the housing portion 1. When the piston body 2 is withdrawn from the housing portion 1, the piston 16 is retained by the undercut 18. When pulled further to the rear, the plunger 15 is detached from the piston 16, as shown in FIG. 5. In this position, the piston 16 forms a tamper-proof feature, which prevents that the liquid or paste present in the cavity 7 can be manipulated or be replaced by some other liquid or paste. Instead of the undercut 18, one or more lamellae and/or hooks can be provided. These parts must also be adjusted to the piston 16 such that it is prevented by these parts from moving out of the housing portion 1. It would also be possible to connect the plunger 15 and the piston 16 by a sealing tape or a similar component, which will tear when trying to withdraw the piston 16 from the housing portion 1. The sealing tape can be produced when injection molding the piston body 2. A further possibility consists in integrally forming the plunger 15 and the piston 16 and connecting them with each other by a predetermined breaking point. In the embodiment shown in FIG. 4, the piston body 2 is made of one piece. For this purpose, the plunger 15 and the piston 16 can be formed integrally. However, the plunger 15 and the piston 16 can also be made of two pieces and be non-releasably connected with each other. In both cases, the entire piston body 2 consisting of plunger 15 and piston 16 would be prevented from being withdrawn from the housing portion 1 by the undercut 18 or a similar component. The Figures of the drawing show a housing portion 1 and a piston body 2 of circular cross-section. However, other cross-sectional shapes are also possible, such as a cross shape or some other shape. Another locking possibility consists in providing an indentation or bulge in the plunger 15, which cooperates with the undercut or a similar part of the housing portion 1 such that withdrawing the plunger 15 from the housing portion 1 no longer is possible. The invention creates a tamper-proof feature for a pre-filled injector or applicator, which prevents that liquid or paste filled in can be manipulated or that some other liquid or paste than the one filled in originally can be employed. The drawings show an injector for dispensing a liquid or pasty drug. However, the invention is also applicable to an applicator for dispensing a liquid or pasty drug.
|
A
|
A61
|
A61M
|
5
|
50
|
|||||
11823672
|
US20090006885A1-20090101
|
Heartbeat distribution that facilitates recovery in the event of a server failure during a user dialog
|
ACCEPTED
|
20081216
|
20090101
|
[]
|
G06F1120
|
["G06F1120", "G06F1516"]
|
8201016
|
20070628
|
20120612
|
714
|
004000
|
59198.0
|
TRUONG
|
LOAN
|
[{"inventor_name_last": "Pattabhiraman", "inventor_name_first": "Ramesh V.", "inventor_city": "New Albany", "inventor_state": "OH", "inventor_country": "US"}, {"inventor_name_last": "Vemuri", "inventor_name_first": "Kumar V.", "inventor_city": "Naperville", "inventor_state": "IL", "inventor_country": "US"}]
|
An exemplary method facilitates automatic recovery upon failure of a server in a network responsible for replying to user requests. Periodic heartbeat information is generated by a first group of servers responsible for replying to user requests. The heartbeat information provides an indication of the current operational functionality of the first group of servers. A second group of servers determines that one of the first servers has failed based on the periodic heartbeat information. The second group of servers is disposed in communication channels between users and the first group of servers. One of the second group of servers receives a message containing a request from a first user having the one of the first group of servers as a destination. One of the second group of servers determines that the message is part of an ongoing dialog of messages between the first user and the one of the first group of servers. Stored dialog information contained in previous communications between the first user and the one of the first group of servers associated with the ongoing dialog is retrieved. Another message is transmitted from the one of the second group of servers to another of the first group of servers. The another message includes the request contained in the message and the retrieved dialog information. This enables the another server to process the request based on the retrieved dialog information without requiring the first user to have to retransmit previously transmitted information that was part of the dialog information.
|
1. A method for automatic recovery upon failure of a server in a network responsible for replying to user requests comprising the steps of: generating periodic heartbeat information by each of a plurality of first servers of a first type responsible for replying to user requests where the heartbeat information provides an indication of the current operational functionality of each of the first servers; receiving the periodic heartbeat information at each of a plurality of second servers of a second type and determining at each of the plurality of second servers of a second type that one of the first servers has failed based on the periodic heartbeat information, where the second servers have access to communication channels between users and the first servers; receiving by one of the second servers a message containing a request from a first user having the one of the first servers as a destination; determining by the one of the second servers that the message is part of an ongoing dialog of messages between the first user and the one of the first servers; causing stored dialog information contained in previous communications between the first user and the one of the first servers associated with the ongoing dialog to be retrieved; transmitting another message from the one of the second servers to another of the first servers that is not the one of the first servers, where the another message includes the request contained in the message and the retrieved dialog information, thereby enabling the another server to process the request based on the retrieved dialog information without requiring a retransmission from the first user of previously transmitted information that was part of the dialog information. 2. The method of claim 1 further comprising the step of transmitting the heartbeat information for each of the first servers to each of the second servers. 3. The method of claim 1 further comprising the step of storing information contained in messages that flow through the respective second servers at one of a database resource accessible to the respective second servers and a user's communication device, so that the stored information associated with each dialog can be separately identified and retrieved. 4. The method of claim 1 further comprising the step of processing, by the another first server, the request by using information contained in the received dialog information. 5. The method of claim 4 wherein the processing by the another first server of the request requires access to certain information contained in the received dialog information in order for a responsive reply to be transmitted by the another first server to the first user. 6. The method of claim 1 further comprising the steps of storing at the one of the second servers an identity of the dialog information of which the message is a member and storing an identity of the another first server. 7. The method of claim 6 further comprising the step of routing further messages from the first user that are part of the identified ongoing dialog messages to the identified another first server. 8. A first server that facilitates automatic recovery upon failure of one of second servers in a network responsible for replying to user requests comprising: a microprocessor controlled apparatus that receives periodic heartbeat information for each of the second servers of a second type responsible for replying to user requests where the heartbeat information provides an indication of the current operational functionality of the respective second servers; the microprocessor controlled apparatus determines that the one of the second servers has failed based on the periodic heartbeat information, where the microprocessor controlled apparatus supports communication channels between users and the second servers; the microprocessor controlled apparatus receives a message containing a request from a first user having the one of the second servers as a destination; the microprocessor controlled apparatus determines that the message is part of an ongoing dialog of messages between the first user and the one of the second servers; the microprocessor controlled apparatus causing stored dialog information contained in previous communications between the first user and the one of the second servers associated with the ongoing dialog to be retrieved; the microprocessor controlled apparatus transmits another message to another of the second servers that is not the one of the second servers, where the another message includes the request contained in the message and the retrieved dialog information, thereby enabling the another server to process the request based on the retrieved dialog information without requiring a retransmission from the first user of previously transmitted information that was part of the dialog information. 9. The first server of claim 8 further comprising the microprocessor controlled apparatus storing information contained in messages that flow through the first server so that the stored information associated with each dialog can be separately identified and retrieved. 10. The first server of claim 8 wherein processing by the another second server of the request requires access to certain information contained in the received dialog information in order for a responsive reply to be transmitted by the another second server to the first user. 11. The first server of claim 8 further comprising the microprocessor controlled apparatus storing an identity of the dialog information of which the message is a member and storing an identity of the another second server. 12. The first server of claim 11 further comprising the microprocessor controlled apparatus routing further messages from the first user that are part of the identified ongoing dialog messages to the identified another second server. 13. A method for providing nodes in a network with heartbeat information comprising the steps of: receiving periodic heartbeat information at a central node for each of a plurality of first nodes of a first type responsible for replying to user requests where the heartbeat information provides an indication of the current operational functionality of the respective first nodes; generating one message at the central node based on the periodic heartbeat information where the one message contains heartbeat information associated with each of the first nodes; transmitting from the central node the one message to each of a plurality of second nodes of a second type that differs from the first type; determining at each of the second nodes based on the received one message whether each of the first nodes is currently capable of providing its respective normal functionality. 14. The method of claim 13 further comprising the steps of determining at one of the second nodes that one of the first nodes is not currently capable of providing its normal functionality, and assigning by the one of the second nodes another of the first nodes to handle user requests received by the one of the second nodes designated by the user to be processed by the one of the first nodes. 15. The method of claim 13 further comprising the steps of: receiving periodic heartbeat information at the central node for each node in the network where the heartbeat information provides an indication of the current operational functionality of the respective nodes; generating the one message at the central node based on the periodic heartbeat information where the one message contains heartbeat information associated with all of the nodes; transmitting from the central node the one message to each of the nodes; determining at each of the nodes based on the received one message whether any other node in the network is not currently capable of providing its respective normal functionality.
|
<SOH> BACKGROUND <EOH>This invention relates to monitoring the health of a cluster of servers that provide services to users. More specifically, this invention relates to using such health information to facilitate a recovery during a user dialog with a server in view of a failure of the server which had been supporting the dialog. Heartbeats have been typically utilized by a single monitoring node to determine the health of other nodes in the network. The single monitoring node may periodically transmit inquiries to each of the nodes being monitored with the expectation of receiving a reply from each within a known time to confirm the health of each node. Detecting the failure of a node by its missing heartbeat at the monitoring node permits the latter to implement alternative actions. For example, the monitoring node may redirect future service requests directed to the failed node to another node. Such action may be sufficient where the service request represents a new initial request for service or is a stand-alone request that is independent of past history involving the failed node. However, as recognized as part of the present invention, redirecting a service request sent to a failed node to another node does not represent an effective solution where the service request is dependent on prior information stored at or exchanged with the failed node, i.e. where the prior history of communications with the failed node is required to process the current request such as in an ongoing dialog. Thus, a need exists for a better recovery technique when a service node fails, especially where a user request is dependent on past communications with the failed node.
|
<SOH> SUMMARY <EOH>It is an object of the present invention to satisfy this need. An exemplary method of the present invention facilitates automatic recovery upon failure of a server in a network responsible for replying to user requests. Periodic heartbeat information is generated by a first group of servers responsible for replying to user requests. The heartbeat information provides an indication of the current operational functionality of the first group of servers. A second group of servers determines that one of the first servers has failed based on the periodic heartbeat information. The second group of servers is disposed in communication channels between users and the first group of servers. One of the second group of servers receives a message containing a request from a first user having the one of the first group of servers as a destination. One of the second group of servers determines that the message is part of an ongoing dialog of messages between the first user and the one of the first group of servers. Stored dialog information contained in previous communications between the first user and the one of the first group of servers associated with the ongoing dialog is retrieved. Another message is transmitted from the one of the second group of servers to another of the first group of servers. The another message includes the request contained in the message and the retrieved dialog information. This enables the another server to process the request based on the retrieved dialog information without requiring the first user to have to retransmit previously transmitted information that was part of the dialog information. Servers that implement the above method provide another exemplary embodiment of the present invention. A tangible computer readable storage medium encoded with control instructions for servers provide a further exemplary embodiment of the present invention.
|
BACKGROUND This invention relates to monitoring the health of a cluster of servers that provide services to users. More specifically, this invention relates to using such health information to facilitate a recovery during a user dialog with a server in view of a failure of the server which had been supporting the dialog. Heartbeats have been typically utilized by a single monitoring node to determine the health of other nodes in the network. The single monitoring node may periodically transmit inquiries to each of the nodes being monitored with the expectation of receiving a reply from each within a known time to confirm the health of each node. Detecting the failure of a node by its missing heartbeat at the monitoring node permits the latter to implement alternative actions. For example, the monitoring node may redirect future service requests directed to the failed node to another node. Such action may be sufficient where the service request represents a new initial request for service or is a stand-alone request that is independent of past history involving the failed node. However, as recognized as part of the present invention, redirecting a service request sent to a failed node to another node does not represent an effective solution where the service request is dependent on prior information stored at or exchanged with the failed node, i.e. where the prior history of communications with the failed node is required to process the current request such as in an ongoing dialog. Thus, a need exists for a better recovery technique when a service node fails, especially where a user request is dependent on past communications with the failed node. SUMMARY It is an object of the present invention to satisfy this need. An exemplary method of the present invention facilitates automatic recovery upon failure of a server in a network responsible for replying to user requests. Periodic heartbeat information is generated by a first group of servers responsible for replying to user requests. The heartbeat information provides an indication of the current operational functionality of the first group of servers. A second group of servers determines that one of the first servers has failed based on the periodic heartbeat information. The second group of servers is disposed in communication channels between users and the first group of servers. One of the second group of servers receives a message containing a request from a first user having the one of the first group of servers as a destination. One of the second group of servers determines that the message is part of an ongoing dialog of messages between the first user and the one of the first group of servers. Stored dialog information contained in previous communications between the first user and the one of the first group of servers associated with the ongoing dialog is retrieved. Another message is transmitted from the one of the second group of servers to another of the first group of servers. The another message includes the request contained in the message and the retrieved dialog information. This enables the another server to process the request based on the retrieved dialog information without requiring the first user to have to retransmit previously transmitted information that was part of the dialog information. Servers that implement the above method provide another exemplary embodiment of the present invention. A tangible computer readable storage medium encoded with control instructions for servers provide a further exemplary embodiment of the present invention. DESCRIPTION OF THE DRAWINGS Features of exemplary implementations of the invention will become apparent from the description, the claims, and the accompanying drawings in which: FIG. 1 is a block diagram of a network suited for incorporation of an embodiment of the present invention. FIG. 2 is a diagram of illustrative nodes as shown in FIG. 1. FIG. 3 is a flow diagram of illustrative steps for distributing heartbeat information in accordance with an embodiment of a method of the present invention. FIG. 4 is a flow diagram of illustrative steps for recovery following a node failure in accordance with an embodiment of a method of the present invention. DETAILED DESCRIPTION One aspect of the present invention resides in the recognition that the mere presence of heartbeats to measure the health of nodes in a network is not necessarily sufficient to efficiently handle recovery upon the occurrence of the failure of a node. This is especially apparent with recovery in a network where an ongoing dialog is begun with a serving node that fails prior to completion of the dialog. As used herein, a “dialog” refers to a series of communications with a server in which processing of one or more of the communications in the series by the server depends upon information or results associated with a prior communication in the series. For example, assume that a user desires to see a map with an area surrounding an address. The user sends the address, city and state to the server as a first part of a dialog. The server utilizes a database to identify the location and transmits a map image to the user showing the address located on the map having a default granularity. After studying the map for a time, the user desires to see the requested location on a map with greater granularity, i.e. a zoom-in of the map at the same address location. The user transmits a zoom-in request to the same server where the zoom-in request does not contain the original address information since the server already has this information. In response, the server generates another map with increased granularity based on the original location information and transmits this image to the user. This completes the services desired by the user and the dialog. This example is illustrative of a dialog because fulfilling the zoom-in request by the server depends upon the original location information received in the prior request. If the server in this example had failed following the transmission of the original map image to the user but prior to the receipt of the zoom-in request, another server to which the zoom-in request could be redirected would not be able to properly service the request since it would not have access to the original address information upon which the zoom-in request is based. As will be explained in more detail below, an embodiment of the present invention more effectively handles a server failure to enable recovery for users while minimizing the need to seek a repeat of prior sent information of the dialog from the users. FIG. 1 shows an illustrative network that supports a plurality of users where each user is supported by communication device 10, 12 and 14. The communication devices may comprise a personal computer, personal digital assistant, cellular telephone or other type of communication device capable of two-way communications, either over a wireline connection or wirelessly. In the illustrative network, front end servers 20, 22, 24, 26 and 28 support communication services with the communication devices of the users. Each front end server is capable of supporting a plurality of users. The front end servers are coupled to a load balancing switch 30 which is also coupled to back end servers 40, 42, 44 and 46. In the illustrative network the back end servers are configured to include resources required to respond to and satisfy requests made by users. The front end servers provide general communication and routing support for the users. The load balancing switch 30 serves as a switch that defines communication channels between the front end and back end servers, and operates to distribute the total load from all users across the back end servers. FIG. 2 is a block diagram of a node 50 such as used in the network is shown in FIG. 1. The architecture shown for node 50 could be utilized for the front end processors/servers, the load balancing switch or the back end servers. A microprocessor 52 is supported by read-only memory (ROM) 54, random access memory (RAM) 56, and nonvolatile data storage device 58 which may be a hard drive. An input/output module 60 is coupled to the microprocessor 52 and supports inbound and outbound communications with external devices. Input devices 62 such as a keyboard or mouse permit an administrator to provide data and control inputs to the microprocessor. Output generated by the microprocessor can be displayed to the administrator by an output device 64 such as a monitor. Program instructions initially stored in ROM 54 and storage device 58 are typically transferred into RAM 56 to facilitate run-time operation of the application implemented by microprocessor 52. Each of the types, i.e. classes, of nodes in FIG. 1 has a different responsibility. The primary application implemented by the front end servers involves handling communications with the communication devices of the users. The primary application associated with the load balancing switch involves control of communication channels and routing of communications over the channels between the front end servers and the back end servers. If node 50 represents the load balancing switch 30, a channel switching unit (not shown) may also be employed to maintain selectable interconnections between channels connecting the front end servers and channels connecting the rear end servers. The primary application implemented by the rear end servers relates to processing user requests, accessing information associated with a user request, and transmitting a reply to a user request, where the reply may include information or data relevant to the request. It will be apparent to those skilled in the art that the stored program instructions in the nodes will support the respective application programs which include the implementation of the illustrative steps of an embodiment of the method in accordance with the present invention as described below. FIG. 3 illustrates the generation and distribution of heartbeat information in accordance with an embodiment of a method of the present invention. In step 100 heartbeat information is obtained, such as by the load balancing switch, for at least each node in one class of nodes. At least each of one type of server, e.g. back end servers, generates a heartbeat as an indication of the health, i.e. operational functionality, of the respective nodes. This information is received by the load balancing switch. In addition to providing health information of a node, the heartbeat may also include other information such as an indication of the load of the respective node. In another embodiment, each of the server nodes of the network, e.g. the front end nodes and the back end nodes, generate heartbeat information that is collected by the load balancing switch 30. In an alternative embodiment of the above, the load balancing switch may utilize a reliable transport to itself issue heartbeats to various nodes belonging to each class of nodes. The success or failure of the heartbeat delivery step can serve as a direct indicator of the health of the nodes that were “pinged” in each case. As used herein receiving heartbeat information includes any technique by which the heartbeat information can be obtained. Each heartbeat ping may itself contain the health information of the other class of nodes that that node might be interested in. This information could be further augmented with load information if the nodes themselves were to convey that in a periodic pulse to the load balancing switch. Since the load balancing switch starts with minimal information about the health of the nodes in the cluster but builds this knowledge up as it successfully pings more and more nodes with heartbeat reports, this process of cluster health information collection and dissemination represents a “growth spiral heartbeat mechanism”. In step 102 the heartbeat information collected by the load balancing switch is combined into a message. That is, all of the currently available heartbeat information for all nodes reporting heartbeat information is combined into one message so that the health of each can be determined based on receipt of this message. Of course, other information associated with the heartbeat information, e.g. loading of each node, will also be contained in the message. In step 104 the heartbeat information of each of at least one class of nodes is communicated to at least each of another class of nodes by transmitting the one message to the latter. For example, the heartbeat information for each of the back end servers can be communicated by the load balancing switch by sending the message to each of the front end servers. This provides each of the front end servers with information concerning the operational status and load associated with each of the back end servers. In another embodiment in which each of the nodes communicates heartbeat information with each of the other nodes, each node in the network will report its operational status and load information to a central collecting node which will collect this information into a message and transmit the message to each of the other nodes in the network. The heartbeats can be automatically generated on a periodic basis. Alternatively, one or more nodes in the network, e.g. a central collecting node, can be responsible for polling each of the nodes in the network for heartbeat information. FIG. 4 is a flow diagram that shows exemplary steps for recovery upon the failure of a back end server in accordance with an embodiment of a method of the present invention. In this example a user is engaged in a dialog via a front end server and load balancing switch with a back end server, and the back end server experiences a failure prior to the conclusion of the dialog. In accordance with the embodiment of the present invention, a recovery is provided by which a continuance of the dialog with another back end server proceeds without requiring the user to input information previously provided earlier in the dialog. This is facilitated by the front end server handling the dialog recognizing the failure of the back end server based on the received heartbeat information. To provide a more concrete example, assume that the user associated with communication device 12, supported by front end server 22 and load balancing switch 30, is in a dialog in which services are being supplied by back end server 42. In step 150 front end server 22 receives periodically updated heartbeat information, such as in a message from the load balancing switch containing health information for each of the back end servers. Front end server 22 may also store information associated with each dialog handled through it. For example, at the beginning of a dialog supported through front end server 22, a record can be generated in a database associated with server 22 that identifies the user's communication device 12, the back end server 42 and a dialog identification number. All information contained in communications between the user and the back end server involving this dialog that flow through the front end server 22 can be stored in this record. Assuming the communication protocol communicates an indication signifying the conclusion of the dialog, server 22 can cause the associated record to be deleted upon the end of subject dialog or after a predetermined time of inactive communications associated with the dialog. Alternatively, the dialog information may be stored elsewhere such as in the user's communication device such as in cookies. In step 152 a determination is made of whether a node of another class of nodes has failed based on received heartbeat information such as in a message from the load balancing switch. In this example, front end node 22 will periodically make determinations about the health of the back end servers based on received heartbeat information. A NO determination by step 152, indicating no failure of any of the back end servers, results in the front end server continuing to route communications normally between the user communication devices and the assigned back end servers. In accordance with this example, the user of communication device 12 is an ongoing dialog with back end server 42 as supported by front end server 22. The ongoing dialog consists of periodic messages sent from the user to the back end server 42 with corresponding replies sent from the back end server 42 to the user. Upon an initial communication from the user to start the subject dialog, one of the back end servers is assigned by the load balancing switch 30 to handle the dialog. Subsequent communications during the dialog from the user would be routed to the same back end server. A YES determination by step 152, representing that a node failure has been detected, causes the identity of the failed node to be stored as in step 156. In this example, front end server 22 detects the failure of back end server 42 and stores its identity as a failed node. In step 158 a determination is made of whether the front end server 22 detects the receipt of another message in an ongoing dialog addressed for the failed node. In this example, the user of communication device 12 has transmitted another communication in the ongoing dialog that had been supported by back end server 42, i.e. the user will be unaware that back end server 42 is no longer operative. A NO determination by step 158, representing that a received message from a user is not another message in an ongoing dialog series with the failed server, results in further processing at step 154, i.e. normal routing of the message to load balancing switch 30 is made by the front end server for distribution to the assigned back end server. A YES determination by step 158, representing that the received message from a user is another message in an ongoing dialog with the failed server, results in further processing as indicated at step 160. Front end server 22 identifies this dialog and causes the stored record of information associated with the subject ongoing dialog to be retrieved. The current received message is routed along with the retrieved relevant information to another assigned node of the same class as the failed node. Alternatively, if the information may be stored elsewhere, e.g. in the user's communication device, the front end server can generate a request to the device storing the dialog information for the storage device to transmit this information to another back end server selected by the front end server that will handle the continuing dialog. Front end server 22 selects another back end server, e.g. back end server 44, to continue providing the user with services associated with the ongoing dialog previously supported by back end server 42. Because the back end server 44 will receive the current message as well as all of the information associated with the previous messages of the ongoing dialog, the back end server 44 will be able to continue to provide services to the user associated with the ongoing dialog without having to query the user for required information available from the stored dialog. In accordance with step 162, any further messages from the user in the same dialog are routed to the new assigned node. That is, further messages in the same dialog from the user associated with communication device 12 initially addressed to back end server 42 will automatically be readdressed by front end server 22 to have back end server 44 as the destination node. In a possible alternative embodiment of the invention, the dialogs may be proactively recovered by the front-end node when a back-end node failure is detected and notified to the front-end node through heartbeats. In this scenario, the front-end node may opt not to wait till the next request from a client arrives within the established dialog context, but may proactively choose to populate state in a different back-end server for each of the dialogs it had associated with that server. This way, idle cycles on the front-end server can be utilized to perform “dialog maintenance” functions, and new incoming requests for failed dialogs do not take significantly longer to process. This represents a proactive dialog recovery. This provides an efficient and beneficial solution to difficulties which arise with the failure of a server during an ongoing user dialog in which services are being provided by the failed server. Such a recovery from a failure of a servicing node prevents the user from being burdened to retransmit all or at least a portion of the information that had been previously transmitted to and/or handled by the failed node. This is supported by the failure of the servicing node being made known to another transporting node based on the heartbeat information. In accordance with embodiments of the present invention, an automatic recovery is accomplished where the user experiences an uninterrupted call flow for the dialog. The nodes in one example employ one or more computer-readable signal-bearing tangible media. The computer-readable signal-bearing media store software, firmware and/or assembly language for performing one or more portions of one or more embodiments of the invention. The computer-readable signal-bearing medium for the nodes in one example comprise one or more of a magnetic, electrical, optical, biological, and atomic data storage tangible medium. For example, the computer-readable signal-bearing medium comprise floppy disks, magnetic tapes, CD-ROMs, DVD-ROMs, hard disk drives, and electronic memory. Although exemplary implementations of the invention have been depicted and described in detail herein, it will be apparent to those skilled in the art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the invention. With regard to the illustrative steps of an embodiment of a method of the present invention, other steps can be substituted, steps deleted, and/or the steps could be practiced in a different order or by a different apparatus. Heartbeat information can be communicated by transmitting and receiving a heartbeat from each node to every other node in another class. Any node or network element through which communications from an external device such as a user's communication device will travel prior to reaching a servicing node can be utilized to reassign a different service node in the event of a failure of the service node supporting a dialog. Alternatively, one node could monitor for the failure of a servicing node while a different network element is utilized to reassign a different service node in the event of a failure. In accordance with the illustrative network, the front end servers could monitor for the failure of a back end server while the load balancing switch functions to reassign a different back end server in the event of a failure of a back end server. Because all service requests flow through the load balancing switch in the illustrative embodiment, the load balancing switch could monitor for failure of a back end server, cause a retrieval of the prior related dialog information, and reassign a different back end server in the event of a failure of a back end server with an ongoing user dialog. More than two classes of nodes can utilize the heartbeat information distribution and automatic recovery techniques described herein. The scope of the invention is defined in the following claims.
|
G
|
G06
|
G06F
|
11
|
20
|
|||
11852591
|
US20090067013A1-20090312
|
SYSTEMS AND METHODS TO ASSOCIATE INVOICE DATA WITH A CORRESPONDING ORIGINAL INVOICE COPY IN A STACK OF INVOICES
|
ACCEPTED
|
20090225
|
20090312
|
[]
|
H04N104
|
["H04N104"]
|
8650221
|
20070910
|
20140211
|
707
|
743000
|
90946.0
|
CHBOUKI
|
TAREK
|
[{"inventor_name_last": "DIXON", "inventor_name_first": "GRAEME NEVILLE", "inventor_city": "Carmel", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Kwok", "inventor_name_first": "Thomas Yu-Kiu", "inventor_city": "Washington Township", "inventor_state": "NJ", "inventor_country": "US"}, {"inventor_name_last": "Laredo", "inventor_name_first": "Jim A.", "inventor_city": "Katonah", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Maradugu", "inventor_name_first": "Sridhar", "inventor_city": "Yorktown Heights", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Nguyen", "inventor_name_first": "Thao Ngoc", "inventor_city": "Katonah", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "White", "inventor_name_first": "Brian L.", "inventor_city": "Brookfield", "inventor_state": "CT", "inventor_country": "US"}]
|
A system and method for associating documents includes providing a plurality of scanned documents of different types and identifying a document type for each scanned document by comparing a determined pattern for each scanned document to known document patterns. Metadata values are extracted from each scanned document using metadata labels, and each scanned document is identified by using extracted metadata values. A stored electronic record is associated with each scanned document by employing the extracted metadata values such that a relationship between the stored electronic record and the associated scanned document is determined and stored.
|
1. A method for associating documents, comprising: providing a plurality of scanned documents of different types; identifying a document type for each scanned document by comparing a determined pattern for each scanned document to known document patterns; extracting metadata values from each scanned document using metadata labels; identifying each scanned document using extracted metadata values; and associating a stored electronic record with each scanned document by employing the extracted metadata values such that a relationship between the stored electronic record and the associated scanned document is determined and stored. 2. The method as recited in claim 1, wherein providing a plurality of scanned documents of different types includes providing a plurality of portable document format documents of different types. 3. The method as recited in claim 1, wherein the different types include different types of financial documents. 4. The method as recited in claim 1, further comprising converting the scanned documents to text documents. 5. The method as recited in claim 1, wherein identifying a document type includes identifying at least two patterns in each document to compare to the known patterns. 6. The method as recited in claim 5, wherein the patterns are identified on a first and last page of a document. 7. The method as recited in claim 1, wherein extracting metadata values from each scanned document includes extracting at least two metadata values from each scanned document including a transaction identifier. 8. The method as recited in claim 1, further comprising the steps of: identifying unresolvable scanned documents; and manually determining at least one of document type and transaction identity for the unresolvable PDF documents. 9. The method as recited in claim 1, wherein one of the scanned documents includes a receipt and the stored electronic record includes an extensible markup language document memorializing a purchase associated with the receipt and further comprising invoicing a customer with an invoice including a copy of the receipt and the extensible markup language document in an on-line application. 10. The method as recited in claim 1, further comprising the step of separating the scanned documents after identification to be stored as individual documents. 11. A computer readable medium comprising a computer readable program for associating documents, wherein the computer readable program when executed on a computer causes the computer to perform the steps of: identifying a document type for each scanned document by comparing a determined pattern for each scanned document to known document patterns; extracting metadata values from each scanned document using metadata labels; identifying each scanned document using extracted metadata values; and associating a stored electronic record with each scanned document by employing the extracted metadata values such that a relationship between the stored electronic record and the associated scanned document is determined and stored. 12. A method for associating documents, comprising: providing a plurality of portable document format (PDF) documents representing sales receipts of different types; identifying a document type for each PDF document by comparing determined patterns in each PDF document to known document patterns to classify the PDF documents as certain types; converting each PDF document to a text file; extracting metadata values from each text file to identify each scanned document by extracting the metadata values using known metadata labels; associating a stored electronic record with each PDF document by employing the extracted metadata values such that a relationship between the stored electronic record and the associated scanned document is determined; and generating an invoice for payment including the stored electronic record and an associated PDF document as an attachment to the stored electronic record. 13. The method as recited in claim 12, wherein the different types include different types of sales receipts. 14. The method as recited in claim 12, wherein identifying a document type includes identifying at least two patterns in each PDF document to compare to the known patterns. 15. The method as recited in claim 14, wherein the patterns are identified on a first and last page of a PDF document. 16. The method as recited in claim 12, wherein extracting metadata values from each PDF document includes extracting at least two metadata values from each PDF document including a transaction identifier. 17. The method as recited in claim 12, further comprising the steps of: identifying unresolvable PDF documents; and manually determining at least one of document type and transaction identity for the unresolvable PDF documents. 18. The method as recited in claim 12, wherein the stored electronic record includes an extensible markup language document memorializing a purchase associated with a sales receipt document of the plurality of PDF documents and further comprising invoicing a customer with an invoice including a copy of the receipt and the extensible markup language document in an on-line application. 19. The method as recited in claim 12, further comprising the step of separating the PDF documents after identification to be stored as individual documents. 20. A computer readable medium comprising a computer readable program for associating documents, wherein the computer readable program when executed on a computer causes the computer to perform the steps in accordance with claim 12.
|
<SOH> BACKGROUND <EOH>1. Technical Field The present invention relates to metadata extraction and correlation from documents, and more particularly to systems and methods for extracting specific metadata automatically from a particular document in a stack or collection of documents of different types to associate documents. 2. Description of the Related Art In any existing invoice transaction, process and payment solutions which provide invoice services to an enterprise, a number of improvements can be made. In most generic invoice transactions, process solutions and payment solutions, the XML invoice data are fed to generic invoice transaction, and process and payment systems through generic Enterprise Transaction systems. The corresponding original invoice copies in non-XML formats are uploaded separately to the invoice system through an Enterprise Resource Planning (ERP) system in a bulk process. A corresponding original invoice copy for the customer is a separate document and not provided to the customer when the customer is billed for payment on a Web application invoice. Therefore, a need exists for associating each original invoice copy with its XML invoice transaction and processes. Currently, metadata, such as the invoice transaction identification, is used as a link reference. The metadata can be manually input into any invoice transaction, process and payment system. However, this manual process is tedious, costly and prone to errors.
|
<SOH> SUMMARY <EOH>In accordance with present principles, embodiments disclosed herein associate or link an extensible markup language (XML) invoice or data with its corresponding original invoice copy by automatically matching at least one of their metadata, such as an invoice transaction identifier, in a database table in a number of steps. The metadata, such as an invoice transaction identification, from the XML invoice data can be easily parsed using any generic XML parser. It is often difficult to extract specific metadata, such as the invoice transaction identification, automatically for each invoice from a stack of many invoices with different invoice transaction types. This is because the location of the specific metadata is located in different locations. It is more difficult for different transaction types and if the different invoice transaction types are semi-structured or un-structured documents. The present embodiments provide an online presentation of extensible markup language (XML) invoice data and options to attach their corresponding original copies for review and printing. This will benefit both the enterprise and its customers. The attachment of the original invoice copy would greatly improve invoice clarity, accuracy, reduce the number of disputes and improve customer satisfaction. A novel method is described to extract specific metadata, such as the invoice transaction identifier, automatically, for each invoice from a plurality of invoices in different invoice transaction types. When the novel method cannot extract the specific metadata, due to unknown invoice transaction types or other reasons, a new unresolved invoice stack of these unresolved invoices will be created. Moreover, graphical user interfaces (GUIs) are provided for an administrator or user to manually extract the invoice transaction identifiers for these unresolved invoices in an unresolved invoice stack. A system and method for associating documents includes providing a plurality of scanned documents of different types and identifying a document type for each scanned document by comparing a determined pattern for each scanned document to known document patterns. Metadata values are extracted from each scanned document using metadata labels, and each scanned document is identified by using extracted metadata values. A stored electronic record is associated with each scanned document by employing the extracted metadata values such that a relationship between the stored electronic record and the associated scanned document is determined and stored. In other embodiments, the stored electronic record includes an extensible markup language document memorializing a purchase associated with a sales receipt document of the plurality of PDF documents and the system/method further comprises invoicing a customer with an invoice including a copy of the receipt and the extensible markup language document in an on-line application. These and other features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
|
BACKGROUND 1. Technical Field The present invention relates to metadata extraction and correlation from documents, and more particularly to systems and methods for extracting specific metadata automatically from a particular document in a stack or collection of documents of different types to associate documents. 2. Description of the Related Art In any existing invoice transaction, process and payment solutions which provide invoice services to an enterprise, a number of improvements can be made. In most generic invoice transactions, process solutions and payment solutions, the XML invoice data are fed to generic invoice transaction, and process and payment systems through generic Enterprise Transaction systems. The corresponding original invoice copies in non-XML formats are uploaded separately to the invoice system through an Enterprise Resource Planning (ERP) system in a bulk process. A corresponding original invoice copy for the customer is a separate document and not provided to the customer when the customer is billed for payment on a Web application invoice. Therefore, a need exists for associating each original invoice copy with its XML invoice transaction and processes. Currently, metadata, such as the invoice transaction identification, is used as a link reference. The metadata can be manually input into any invoice transaction, process and payment system. However, this manual process is tedious, costly and prone to errors. SUMMARY In accordance with present principles, embodiments disclosed herein associate or link an extensible markup language (XML) invoice or data with its corresponding original invoice copy by automatically matching at least one of their metadata, such as an invoice transaction identifier, in a database table in a number of steps. The metadata, such as an invoice transaction identification, from the XML invoice data can be easily parsed using any generic XML parser. It is often difficult to extract specific metadata, such as the invoice transaction identification, automatically for each invoice from a stack of many invoices with different invoice transaction types. This is because the location of the specific metadata is located in different locations. It is more difficult for different transaction types and if the different invoice transaction types are semi-structured or un-structured documents. The present embodiments provide an online presentation of extensible markup language (XML) invoice data and options to attach their corresponding original copies for review and printing. This will benefit both the enterprise and its customers. The attachment of the original invoice copy would greatly improve invoice clarity, accuracy, reduce the number of disputes and improve customer satisfaction. A novel method is described to extract specific metadata, such as the invoice transaction identifier, automatically, for each invoice from a plurality of invoices in different invoice transaction types. When the novel method cannot extract the specific metadata, due to unknown invoice transaction types or other reasons, a new unresolved invoice stack of these unresolved invoices will be created. Moreover, graphical user interfaces (GUIs) are provided for an administrator or user to manually extract the invoice transaction identifiers for these unresolved invoices in an unresolved invoice stack. A system and method for associating documents includes providing a plurality of scanned documents of different types and identifying a document type for each scanned document by comparing a determined pattern for each scanned document to known document patterns. Metadata values are extracted from each scanned document using metadata labels, and each scanned document is identified by using extracted metadata values. A stored electronic record is associated with each scanned document by employing the extracted metadata values such that a relationship between the stored electronic record and the associated scanned document is determined and stored. In other embodiments, the stored electronic record includes an extensible markup language document memorializing a purchase associated with a sales receipt document of the plurality of PDF documents and the system/method further comprises invoicing a customer with an invoice including a copy of the receipt and the extensible markup language document in an on-line application. These and other features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS The disclosure will provide details in the following description of preferred embodiments with reference to the following figures wherein: FIG. 1 is a block/flow diagram showing a system/method for an automatic data extraction system for electronic contract documents in accordance with one illustrative embodiment; FIG. 2 is a block/flow diagram of a system/method showing the system of FIG. 1 in greater detail in accordance with another illustrative embodiment; FIG. 3 is a diagram depicting a document template portal in accordance with an illustrative embodiment; FIG. 4 is a diagram depicting an unresolved document portal in accordance with another illustrative embodiment; and FIG. 5 is a diagram depicting a plurality of storage tables employed in implementing an illustrative embodiment. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Systems and methods for associating documents (paper or electronic) are provided. The present embodiments, convert files into a searchable format and identify relevant information to permit an association between at least two documents. In one embodiment, a portable document format (PDF) file stack is automatically converted into a text file stack, and each individual document (e.g., invoice) is converted with its transaction type. The embodiment separates, creates and stores each identified invoice as an individual PDF file. The embodiment extracts metadata values from each identified invoice and uses a metadata value to name the invoice PDF file. The embodiment also separates, creates and stores a stack of unresolved PDF invoices. Graphical user interfaces (GUIs) are provided for inputting unique patterns of first and last pages for each invoice transaction type. GUIs are also provided for inputting metadata labels for each invoice transaction type by an administrator. GUIs are available for manually selecting invoice transaction types, and entering invoice names and their metadata values for an unresolved stack of invoices. A commonly assigned disclosure to Kwok, et al. entitled “SYSTEMS AND METHODS TO EXTRACT DATA AUTOMATICALLY FROM A COMPOSITE ELECTRONIC DOCUMENT”, Ser. No. 11/472,868, filed on Jun. 22, 2006 is hereby incorporated by reference in its entirety. Embodiments of the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment including both hardware and software elements. In a preferred embodiment, the present invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc. Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that may include, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD. A data processing system suitable for storing and/or executing program code may include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code to reduce the number of times code is retrieved from bulk storage during execution. Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) may be coupled to the system either directly or through intervening I/O controllers. Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modems and Ethernet cards are just a few of the currently available types of network adapters. The following embodiments will be described in terms of an Invoice to Cash (I2C) application as an Invoice Retrieval and Storage component, which employs invoices as documents. It should be understood that the present invention is broader and may be employed with other systems types and may employ other document types. In addition, the document types may include and/or employ both electronic and paper documents. Referring now to the drawings in which like numerals represent the same or similar elements and initially to FIG. 1, a system/method for associating documents is illustratively shown. In block 12, characteristics or specific patterns of each known invoice transaction type are input into a database of any generic invoice transaction or process systems. Graphical user interfaces (GUIs) may be provided for an administrator or user to input this information. Other input methods, such as executing a set of sequential query language (SQL), can be used as well. Patterns may be manually input or automatically determined using a sample transaction document. Patterns may include things such as a number of lines in a header, a metadata label, a formatting feature, etc. In block 14, for each known invoice transaction type, a few metadata labels are input from extracted values from the invoices. The invoices are preferably PDF files although other scanned or digitized formats are possible. At least one to two of these metadata values, such as an invoice transaction identification number, are used to link or associate corresponding XML invoice data. Different metadata labels can be used for different invoice transaction types. These metadata labels are stored in a database of any generic invoice transaction or process systems. GUIs can be provided for the administrator or user to input this information. Other inputting methods, such as executing a set of SQL inquires, can also be employed. In block 16, characteristics or specific patterns inputted in block 12 are employed from the database to identify each invoice according to its invoice transaction type in an incoming stack of invoices from the generic invoice transaction or process system. These invoices can be for different invoice transaction types. In block 18, the metadata labels inputted in block 14 are employed to extract values from each identified individual invoice file. At least one of these extracted metadata values is a value used to link or associate the value with its corresponding XML invoice data, such as, e.g., the invoice transaction number. Other extracted metadata values can be used as a cross check to the corresponding XML invoice data. One or a combination of a few of these extract metadata values, such as the invoice transaction number, can be used to name this identified individual invoice file. In block 20, each identified invoice is separated as an individual invoice so that it can be stored in the database of the generic invoice transaction or process system. In block 22, when the metadata values of their corresponding metadata labels inputted in block 14 cannot be extracted due to an unknown invoice transaction type or other reasons, a new unresolved invoice stack is created for these unresolved invoices in block 23. In block 24, an inputting method(s) is provided, such as a GUI, for an administrator or user to manually extract at least one metadata value corresponding to a metadata label used to link or associate an invoice with its corresponding XML invoice data for each one of these unresolved invoices in the unresolved invoice stack. In block 26, similar to block 20, the manually identified invoice is then separated as an individual invoice so that it can be stored in the database. In block 27 if the metadata values are still unresolved, then, as in block 22, another new unresolved invoice stack is created for all the invoices that even the administrator or user cannot identify manually in block 28. In block 30, the extraction of at least one specific parameter, such as invoice transaction identification, is made from XML invoice data in an invoice Web page of an invoice Web application using an XML parser, for example. This specific parameter is used to map and match the metadata values of the original invoice copies stored in the database of the generic invoice transaction or process system. The invoice or scanned document (e.g., PDF file) will be associated with the XML transaction record. In block 32, the corresponding original invoice copy with the matching specific parameter and metadata value will be retrieved from the database and uploaded as an attachment to be associated with its corresponding XML invoice data in the invoice Web page of the Web application to provide a payment request. The attachment of this original invoice copy will improve the invoice clarity and accuracy, reduce number of disputes and improve customer satisfaction. Referring to FIG. 2, a invoice retrieval and storage component system/method 100 for associating documents is described in greater detail. In a particularly useful embodiment, focus is on an invoice retrieval and storage component 100 used in any invoice to cash (I2C) application. Invoice retrieval and storage component system/method 100 includes two main components 200 and 300. The first component is a Web based application 200 and includes a plurality of portlets 220, 222, and 224 as shown in FIGS. 3 and 4. These portlets 220, 222, and 224 are accessed by clicking their corresponding URL links on any I2C administrator portlet that passes or provides information on tenant ID (which is, e.g., an identifier for the user) or a database connection to the portlets 220, 222, 224 in the Web based application 200. A second component of the invoice retrieval and storage component system/method 100 is a stand-alone engine 300. Engine 300 uses information entering from the Web component 200 by the administrator to identify each individual invoice with its transaction type from a stack of PDF invoices, and extracts metadata values from the files. Engine 300 also parses and converts the PDF file into a text file. Administrator inputs metadata labels and rules 120 for each invoice transaction type. A user identifies each invoice type, enters invoice name and its metadata values for a stack of unresolved PDF invoices by employing a portlet interface and using tools for handling the unresolved invoices in block 122. The invoice retrieval and storage component system/method 100 retrieves individual PDF invoices from a stack of invoices of different types in block 102. System 100 has input thereto, unique patterns for each invoice transaction type to identify each invoice transaction type in block 104. For example, a transaction type may employ a same form having a similar pattern (e.g., the heading, a return policy statement, etc.). These patterns may be identified by system 100 and employed to classify the PDF file. These patterns may be recognized by a pattern recognition program. The system 100 may employ unique patterns on a portion of the PDF file. In one example, system 100 employs one or more patterns on a first page and a last page of the file or document. In another embodiment, two unique patterns are employed to identify a first page of the invoice transaction type, and two unique patterns are employed to identify the last page of the invoice transaction type. Engine 300 may convert the PDF files to text in block 106. Once the transaction type is identified, the transaction needs to be identified by extracting and comparing metadata in block 108. Engine 300 employs metadata labels to extract metadata values for each invoice transaction, e.g., two metadata values for each invoice transaction. When a stack of invoices of different transaction types in portable document format (PDF) format with text has arrived into any generic invoice to cash application, each invoice is separated and identified as an individual PDF file and type. It should be understood that other bitmap or scanned file formats may also be employed. In blocks 104 and 108, two or more patterns and metadata values are extracted from each identified individual invoice file as described with reference to FIG. 1. This may be performed using optical character recognition and/or converting the file to a text file in block 106. In block 110, the PDF file needs to be associated with its XML file by matching their metadata values. The XML file is a file created by an application and stored in a database for generating an invoice or hill to be sent to the purchaser. As an example, a transaction for a purchase may have been conducted on-line, or at a retail establishment where an individual uses a credit card or debit card. At the time of sale an original receipt is generated with a customer signature and scanned or otherwise photographically captured. In addition, an electronic record is created by the vender, preferably in XML. The vender usually desires to attach the original receipt to the XML document for billing and record keeping purposes. To attach the corresponding original invoice copy for the customer when the customer is billed for payment on a Web application invoice, there is a need to associate each original invoice copy with its XML invoice transaction and processes. Thus, the administrator can retrieve the invoice PDF file and send it to the user as an attachment for requesting cash payment. The metadata values are employed to map the invoice PDF with its corresponding XML. In this application, a first portal 220 is employed for presentation, user input, and may be generated using a WPF (WebSphere Portal Factory) tool for portal development. A light weight storage service (LSS) or any generic database storage services 142 is used to read, store, replace and delete files. The portlets described herein preferably communicate backend functions by a web service although other communication configurations may be employed. Engine 300 identifies any invoices where a problem identifying the transaction or transaction type exists and lists these as unresolved in block 122. Then, a user through a user interface or portlet 224 manually enters invoice names and metadata values for each unresolved invoice. Engine 300 may include an Enterprise Resource Planning (ERP) processor 302, which assists in handling the retrieval and processing of files and the distribution and utilization of resources. Engine 300 preferably implements the following: 1) UnitTest: UnitTest tests system 100 by hardcoding all of the input parameters from a property file instead using a daemon and a property file. A data source is needed by a data bean such that the data bean is independent of the property file. An I2C agent calls IncomingPDFFile by passing the data source parameter. This IncomingPDFFile simulates the work of an I2C agent using an application processing interface (API) instead of a Web service interface. 2) IncomingPDFFile: IncomingPDFFile is called by an Enterprise Resource Planning (ERP) processor or UnitTest using an API or Web services interfaces. A Web service interface has been implemented for this java class for the I2C ERP processor to call. Then, the information on an incoming stack of PDF invoices is stored in Table 5 (see FIG. 5), which will be identified hereinafter. 3) MonitorPDFFile: MonitorPDFFile monitors Table 5 to see whether there are any incoming stacks of PDF invoices. If yes, GenerateInvoice is called to proceed. 4) GenerateInvoice: GenerateInvoice is called by MonitorPDFFile with parameters (e.g., tenant Id, input file key, file name, data source). This is a more important java class since five other java classes are called from this class. A Web service call and light weight storage service (LSS) or any generic database storage services may be employed with the AddResultForTransaction to pass the invoice name and metadata values to the system 100. 5) PDFToText: PDFToText converts a PDF to a text file. A Web service call and LSS are used to store the invoice text file. 6) DocIdentify: DocIdentify identifies individual invoices inside the stack of invoices with its type. 7) MetaExtraction: MetaExtraction extracts metadata from each identified invoice. 8) SeparateFile: SeparateFile separates each identified invoice as an individual PDF file. A Web service call and LSS are used to store the invoice text file. 9) UnresolvedFile: UnresolvedFile creates a stack of unresolved PDF invoices. A Web service call and LSS are employed to store the invoice text file. 10) PortletInput: PortletInput is called by the unresolved invoice portlet (224) to create a user identified invoice PDF file with three parameters (invoice name, first page, last page) entered by the user. 11) PortletSeparate: PortletSeparate is called by the PortletInput.java to separate manually identified invoices. A Web service call and LSS are used to store the invoice text file. Referring to FIG. 3, portlet 220 (and/or 222) is shown for creating templates and identifying patterns in documents. A Document Scanning Template setup is called in portlet 220 when a user clicks on a link (e.g., Doc Scanning Templates in block 232) in a client setup menu 230. DocScanning Template portlet 220 permits the user to configure document templates for the invoices. This portlet 220 (and/or 222) displays a list 234 of document templates for a tenant. The templates in the list 234 may include invoice, credit memo, journal, remittance, etc. When the user clicks on any of the document templates, if the template is already configured it will bring up a display page 239. The user can update the details on page 239 for the document template. The page 239 has two parts. A top part 237 is to configure Invoice Patterns and a bottom part 238 is to configure document key variables. If the user unchecks a Single page document check box 240, the user can configure invoice patterns for additional pages (e.g., a First page and a Last page). The user has to enter at least one invoice pattern to configure the document template. Matching phrase, line number, top or bottom, page values are exemplary parameters needed in the setup process. If the user blanks out phrase and line values, the invoice pattern will be removed for the selected document template. The user can configure the key variables for the document templates as well. The user has to enter at least one set of key values to configure the document template. If the user blanks out all the fields in the row the key values entries will be removed for the selected document template. When the user clicks on a save button 242 all the changes will be saved for the selected document template. A status message, if any errors occur, will be shown to the user. The GUIs of the portlet 220 (222) provide an administrator the capabilities to enter at least two unique patterns of the first and last pages of each invoice transaction type. In this portlet 220 (222), an administrator also needs to input at least two metadata labels for extraction of the corresponding metadata values for each invoice transaction type. For inputting unique patterns and rules for each invoice transaction type to identify each invoice with its transaction type in a stack of PDF invoices, the administrator needs to input at least two unique patterns each for the first page and last page of each invoice transaction type. In one example, for each unique pattern, enter, select or retrieve—TenantId; select—Invoice Type Name; enter—page number (where the unique pattern occurs); select—(counting page number starts from and includes the first page or last page); enter—line number (where the unique pattern occurs); select—(counting line number starts from and includes the top line or bottom line); select—match or missing phrase indicator; enter—phrase (match—at least one; missing—optional). Other inputs may be employed for patterns as well. For inputting metadata labels for each invoice transaction type to extract their values to map the identified PDF invoice file with its corresponding XML invoice file and use the first metadata value as the PDF invoice's new file name, the administrator needs to input metadata labels for each invoice transaction type, preferably at least two metadata labels. For each metadata label: enter, select or retrieve—TenantId; select—Invoice Type Name; enter—metadata label name in phrase; enter—metadata label in phrase as shown in the PDF document; enter—page number (where the metadata label occurs); enter—line number (where the metadata label occurs); enter—word number (where the metadata label phrase begins including the first word of the metadata label phrase); enter—number of terms (next to the metadata label phrase) to be extracted as its value; select—position (left—terms after the last word of the metadata phrase, right—terms before the first word of the metadata phrase, above—terms located in the preceding above the first word of the phrase, below—terms located in the next line below the first word of the phrase). Other inputs may be employed for metadata as well. Referring to FIG. 4, portlet 224 for unresolved stacks is illustratively shown. Unscanned Documents Portlet 224 is called when the user clicks on Resolve UnScanned Docs 250 link in Client Setup Menu 230 (FIG. 3). This page 252 displays a list 254 of unresolved invoices or documents. If the user clicks on the file and image or the unresolved document will be shown in a new browser window (not shown). The user can go through the document and identify the document template for the invoice or the invoice itself. To remove any one of the files, the user has to select that file and click on a remove button 253, this action will remove the file from the list. Once the user selects the file to be resolved from the list 254, information about the file will be displayed in area 256. The user has to click on an Add Document button 257 to enter a start page 260, end page 262 and document key variables 264 for a new selected file. After entering the details, the user clicks on a save button 258 to save. The user can enter a plurality of document templates for each file. After entering the document template details, when the user clicks on a done button 266, the unresolved document will be resolved and stored. A status message will be shown to the user. If any error occurred, an error message will be displayed. The GUIs of portlet 224 provide an administrator the capabilities to manually identify the transaction type of each invoice in a stack of unresolved invoices. For inputting file name and values of metadata labels for each manually identified invoice in a stack of unresolved PDF invoices, the administrators need to input metadata values, preferably two, for each identified invoice with each transaction type. For each identified invoice with each transaction type: enter, select or retrieve—TenantId; select—Invoice Transaction Type Name for this identified PDF invoice; enter—file name for the identified PDF invoice; enter—starting page number (in the stack where the identified invoice starts from); enter—ending page number (in the stack where the identified invoice ends); display—the first metadata label in a phrase for the selected invoice transaction type; enter—the first metadata label's corresponding metadata value in the phrase; display—the second metadata label in phrase for the selected invoice transaction type; enter—the second metadata label's corresponding metadata value in the phrase. Other inputs may be employed for metadata and metadata labels as well. For those pages in the stack of unresolved PDF invoices not being identified as belonging to any of the manually identified invoices, code will replace the stack of unresolved PDF invoices with a new stack of unresolved PDF invoices including these unresolved pages and using the original file name. If all the pages in the stack of unresolved PDF invoices have been identified and belong to the manually identified invoice, then the code will delete this stack. Referring to FIG. 5, a plurality of tables is described for implementing the system/method in accordance with the present principles. System 100 may include one or more tables to implement functions as described herein. These tables are provided for illustrative purposes to demonstrate the type of information collected and employed at different process stages. A Table 1 (InvoiceType) includes Invoice transaction type numbers (InvoiceTypeNo) and names (InvoiceTypeName) for different tenant Ids (TenantId). Table 2 (InvoicePattern) includes Patterns and rules for each known invoice transaction type. Two entries are provided for each of the first and last page. PatternRefNum, InvoiceTypeNo, PageNo, FirstLast, LineNo, TopBot, MatchInd, and Phrase are included in Table 2. Table 3 (MetadataLabel) includes Metadata labels with locations and rules for each known invoice type. Two metadata labels are provided for each invoice transaction type. The columns of Table 3 include MetadataRefNo, InvoiceTypeo, MetadataName, MetadataLabel, PageNo, LineNo, WordNo, NoOfTerms, Position. Table 4 (MetadataValue) includes Name, URL, and two pairs of metadata names and values for each matched invoice. Value1 is employed as an invoice name for this table, Value1 can be replaced by addResultForTransaction. The columns of Table 4 include InvoiceRefNo, InvoiceTypeNo, LSSFileKey, InvoiceName, Label1, Value1, Label2, and Value2. Table 5 (InvoiceStack) is for incoming and unresolved stack of invoices. The columns of Table 5 include FileRefNo FileName, TenentId, LSSFileKey, FileName, and FileINd. Having described preferred embodiments for systems and methods to associate invoice data with a corresponding original invoice copy in a stack of invoices (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments disclosed which are within the scope and spirit of the invention as outlined by the appended claims. Having thus described aspects of the invention, with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.
|
H
|
H04
|
H04N
|
1
|
04
|
|||
11851156
|
US20080066795A1-20080320
|
CANOPY WITH AUTOMATIC ROOF STRUCTURE HAVING IMPROVED STRUCTURAL STABILITY
|
ACCEPTED
|
20080305
|
20080320
|
[]
|
E04H1550
|
["E04H1550"]
|
7836908
|
20070906
|
20101123
|
135
|
145000
|
78095.0
|
JACKSON
|
DANIELLE
|
[{"inventor_name_last": "Sy-Facunda", "inventor_name_first": "Ron", "inventor_city": "Thousand Oaks", "inventor_state": "CA", "inventor_country": "US"}]
|
The technology of the present application provides a canopy with an automatic roof structure having improved structural stability. The canopy comprises a plurality of vertical support posts connected by trusses. A plurality of roof support rods extend from the vertical support posts to a central hub. At least one of the roof support rods has a cantilever support extending from the associated slide or thereabouts to a pivot on the roof support rod. The canopy also comprises central truss supports and stubs extending from the connection of the lateral trusses to the central hub. The canopy has an expanded, open configuration and a collapsed, closed configuration.
|
1. A collapsible canopy, comprising: a canopy cover; and a canopy frame to support the canopy cover, the canopy frame comprising: a plurality of vertical corner support posts; a plurality of trusses linking each pair of the plurality of vertical corner support posts, each of the plurality of trusses having an expanded position and a collapsible position, comprising: a first member having a first fixed end fixedly coupled to one of the plurality of upwardly extending poles and a second end coupled to the second end of another first member; a second member having a third movable end slidably coupled to one of the plurality of upwardly extending poles and a fourth end coupled to the forth end of another second member; a central hub; a plurality of roof support rods, each of the plurality of roof support rods comprising a first end pivotally coupled to a top of one of the vertical corner support posts and pivotally coupled to the central hub such that the central hub is above a plane defined by the tops of the plurality of vertical corner support posts, each of the plurality of roof support rods having an expanded position and a collapsible position; and a plurality of central truss supports, each of the plurality of central truss supports being pivotally connected to one of the plurality of trusses at a first end and the pivotally coupled to the central hub at the second end. 2. The collapsible canopy of claim 1, wherein each of the plurality of roof support rods comprises a hinge to allow the roof support rod to fold between the collapsed position and the extended position. 3. The collapsible canopy of claim 1, further comprising at least one cantilever support arm, the at least one cantilever support arm pivotally coupled to at least one roof support rod and pivotally and slidably coupled to at least one of the vertical corner support post. 4. The collapsible canopy of claim 1, wherein the plurality of vertical corner support post are canted. 5. The collapsible canopy of claim 1, wherein the central hub comprises: roof support connection to which the plurality of roof support rods are pivotally coupled and a central truss support connection to which the plurality of central truss supports are pivotally coupled, and the roof support connection and the central truss support connection are coupled together. 6. The collapsible canopy of claim 5, wherein the central truss support connection and the roof support connection are coupled by a vertical roof support post, the vertical roof support post fixedly coupled to the roof support connection and slidably coupled to the central truss support. 7. The collapsible canopy of claim 6, wherein the vertical roof support post is slidably coupled to a bore in the central truss support. 8. The collapsible canopy of claim 3, wherein the at least one cantilever comprises a plurality of cantilevers that corresponds to the plurality of roof support rods. 9. The collapsible canopy of claim 1, wherein the central truss support is pivotally coupled to the plurality of trusses at a point proximate the fourth end of the second member and the fourth end of the another second member. 10. The collapsible canopy of claim 9, wherein the central truss support comprises a hinge wherein the central truss support has an extended position and a collapsed position. 11. The collapsible canopy of claim 9, wherein the central truss support further comprises a stud pivotally coupled to the central truss support and pivotally coupled at a point proximate the second end of the first member and the second end of the another first member. 12. A collapsible canopy with a roof support assembly, the canopy frame having a plurality of vertical corner support posts and a plurality of trusses linking each pair of the plurality of vertical corner support posts, each of the plurality of trusses having an expanded position and a collapsible position with a first member having a first fixed end fixedly coupled to one of the plurality of upwardly extending poles and a second end coupled to the second end of another first member and a second member having a third movable end slidably coupled to one of the plurality of upwardly extending poles and a fourth end coupled to the forth end of another second member, the roof support assembly comprising: a central hub, the central hub comprising a roof support connection to which the plurality of roof support rods are pivotally coupled, a central truss support connection to which the plurality of central truss supports are pivotally coupled, and vertical roof support post coupling the roof support connection and the central truss support connection, the vertical roof support post slidably coupled to the central truss support connection; a plurality of roof support rods, each of the plurality of roof support rods comprising a first end pivotally coupled to a top of one of the vertical corner support posts and pivotally coupled to the central hub such that the central hub is above a plane defined by the tops of the plurality of vertical corner support posts, each of the plurality of roof support rods having an expanded position and a collapsible position; and a plurality of central truss supports, each of the plurality of central truss supports being pivotally connected to one of the plurality of trusses at a first end and the pivotally coupled to the central hub at the second end. 13. A collapsible canopy, comprising: a canopy cover; and a canopy frame to support the canopy cover, the canopy frame comprising: a plurality of vertical corner support posts; a plurality of trusses linking each pair of the plurality of vertical corner support posts, each of the plurality of trusses having an expanded position and a collapsible position, comprising: a first member having a first fixed end fixedly coupled to one of the plurality of upwardly extending poles and a second end coupled to the second end of another first member; a second member having a third movable end slidably coupled to one of the plurality of upwardly extending poles and a fourth end coupled to the forth end of another second member; a central hub; a plurality of roof support rods, each of the plurality of roof support rods comprising a first end pivotally coupled to a top of one of the vertical corner support posts and pivotally coupled to the central hub such that the central hub is above a plane defined by the tops of the plurality of vertical corner support posts, each of the plurality of roof support rods having an expanded position and a collapsible position; and means for providing increased lateral support for the roof pivotally coupled to one of the plurality of trusses at a first end and the pivotally coupled to the central hub at the second end. 14. The collapsible canopy of claim 13, wherein the means for providing increased lateral support for the roof comprises a plurality of central truss supports, each of the plurality of central truss supports being pivotally connected to one of the plurality of trusses at a first end and the pivotally coupled to the central hub at the second end and a stub pivotally coupled to the central truss support and pivotally coupled at a point proximate the second end of the first member and the second end of the another first member.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Canopies and other outdoor shade structures have been in existence through history. However, with the advent of improved mechanics and materials, a need has developed to provide canopies with more height, increased head room, lighter weight, easier to use, and increased portability. U.S. Pat. No. 4,607,656, issued on Aug. 26, 1986, to Carter (expired), incorporated herein by reference, discloses an early collapsible canopy that was easier to use and required reduced room to store. The '656 patent specifically relates to a canopy that comprises a plurality of vertical legs connected by X shaped trusses. The X shaped trusses have a bottom portion slidably connected to the vertical legs allowing the plurality of vertical legs to be moved from a closed, stored position to an open, erect position without a complex connection between the various legs. U.S. Pat. No. 4,641,676, issued on Feb. 10, 1987, to Lynch (expired), incorporated herein by reference, discloses a similar canopy structure. While the structures disclosed by the '656 and '676 patents provided improvement over then available portable canopies, which required complex construction and breakdown to use, both the '656 and '676 patents used X shaped trusses extending across the middle of the canopy to provide a support for a top cover. The horizontal X shaped truss extending across the middle of the canopy provided drawbacks, including, for example, the canopy had relatively low clearance. Many improvements have been derived from the original patents relating to canopies having X shaped trusses in an attempt to increase the head clearance of canopies. One particularly elegant design is highlighted by U.S. Pat. No. 4,779,635, issued Oct. 25, 1988, to Lynch. The '635 patent is similar to the above described designs, but provides a roof support member connected to at least one of the vertical legs with a cantilever support. Thus, the canopy still is collapsible into a compact unit for moving and storage, but when extended, the roof members automatically expands above the X shaped trusses. The cantilever provides a mechanism to automatically push the roof members from a folded or retracted position into an unfolded or extended position. While the automatic roof structure of the '635 patent greatly increased headroom and enhanced the easy of operation of the portable device, the higher, angled roof structure tended to decrease the overall structure's stability and strength. Thus, it would be desirous to develop a canopy with an automatic roof structure that has improved structural stability and strength.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The technology of the present application provides a canopy with an automatic roof structure having improved structural stability. The canopy comprises a plurality of vertical support posts connected by trusses. A plurality of roof support rods extend from the vertical support posts to a central hub. At least one of the roof support rods has a cantilever support extending from the associated slide or thereabouts to a pivot on the roof support rod. The canopy also comprises central truss supports and stubs extending from the connection of the lateral trusses to the central hub. The canopy has an expanded, open configuration and a collapsed, closed configuration. The foregoing and other features, utilities and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings
|
PRIORITY INFORMATION Under 35 U.S.C. § 119(e), the present application claims priority to U.S. Provisional Patent Application Ser. No. 60/825,981, filed Sep. 18, 2006, titled CANOPY WITH AUTOMATIC ROOF STRUCTURE HAVING IMPROVED STRUCTURAL STABILITY. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH None. CROSS-REFERENCE TO RELATED APPLICATIONS None. FIELD OF THE INVENTION The present invention relates to a canopy structure and, more particularly, to a canopy structure with an automatic roof structure having improved structural stability. BACKGROUND OF THE INVENTION Canopies and other outdoor shade structures have been in existence through history. However, with the advent of improved mechanics and materials, a need has developed to provide canopies with more height, increased head room, lighter weight, easier to use, and increased portability. U.S. Pat. No. 4,607,656, issued on Aug. 26, 1986, to Carter (expired), incorporated herein by reference, discloses an early collapsible canopy that was easier to use and required reduced room to store. The '656 patent specifically relates to a canopy that comprises a plurality of vertical legs connected by X shaped trusses. The X shaped trusses have a bottom portion slidably connected to the vertical legs allowing the plurality of vertical legs to be moved from a closed, stored position to an open, erect position without a complex connection between the various legs. U.S. Pat. No. 4,641,676, issued on Feb. 10, 1987, to Lynch (expired), incorporated herein by reference, discloses a similar canopy structure. While the structures disclosed by the '656 and '676 patents provided improvement over then available portable canopies, which required complex construction and breakdown to use, both the '656 and '676 patents used X shaped trusses extending across the middle of the canopy to provide a support for a top cover. The horizontal X shaped truss extending across the middle of the canopy provided drawbacks, including, for example, the canopy had relatively low clearance. Many improvements have been derived from the original patents relating to canopies having X shaped trusses in an attempt to increase the head clearance of canopies. One particularly elegant design is highlighted by U.S. Pat. No. 4,779,635, issued Oct. 25, 1988, to Lynch. The '635 patent is similar to the above described designs, but provides a roof support member connected to at least one of the vertical legs with a cantilever support. Thus, the canopy still is collapsible into a compact unit for moving and storage, but when extended, the roof members automatically expands above the X shaped trusses. The cantilever provides a mechanism to automatically push the roof members from a folded or retracted position into an unfolded or extended position. While the automatic roof structure of the '635 patent greatly increased headroom and enhanced the easy of operation of the portable device, the higher, angled roof structure tended to decrease the overall structure's stability and strength. Thus, it would be desirous to develop a canopy with an automatic roof structure that has improved structural stability and strength. SUMMARY OF THE INVENTION The technology of the present application provides a canopy with an automatic roof structure having improved structural stability. The canopy comprises a plurality of vertical support posts connected by trusses. A plurality of roof support rods extend from the vertical support posts to a central hub. At least one of the roof support rods has a cantilever support extending from the associated slide or thereabouts to a pivot on the roof support rod. The canopy also comprises central truss supports and stubs extending from the connection of the lateral trusses to the central hub. The canopy has an expanded, open configuration and a collapsed, closed configuration. The foregoing and other features, utilities and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention, and together with the description, serve to explain the principles thereof. Like items in the drawings are referred to using the same numerical reference. FIG. 1 is a perspective view of a canopy constructed in accordance with the disclosure; FIG. 2 is an elevation view of roof support rods from the canopy of FIG. 1; FIG. 3 is an elevation view of the central truss support FIG. 1 connected to expandable and collapsible trusses; FIG. 4 is a top plane view of the canopy of FIG. 1; and FIGS. 5A and 5B are a detail of the central hub including central truss supports and roof support rods. DETAILED DESCRIPTION Referring now to FIGS. 1-5B, the technology of the present application will now be explained. One of ordinary skill in the art will recognize that the present technology is explained with reference to a portable, instant canopy structure, but the technology could be used in other structures, such as, for example, tents, vehicle ports, or the like. With reference to FIG. 1, a perspective view of a canopy 100 is shown. Only the roof section of canopy 100 is shown in detail for convenience. Canopy 100 includes a plurality of vertical corner support posts 102. Vertical corner support posts 102 may be slightly canted for stability. Moreover, posts 102 may be extendible from a retracted, storage position to an extended, use position as is generally known in the art and not further described or shown for convenience. Connecting adjacent pairs of vertical corner support posts 102 are expandable and collapsible trusses 104. While two sets of expandable and collapsible trusses 104 are shown connecting adjacent pairs of vertical corner support posts 102, more or less are possible as a function of canopy size. In some designs, it may be beneficial to place a vertical wall support post, which would be substantially similar to vertical corner support posts 102 and is not separately shown or described. As shown, each truss 104 comprises a first member 106 pivotally connected to a second member 108 at pivot point A where first member 106 and second member 108 cross. First member 106 has a first end 110 connected to a top 112 of associated vertical corner support post 102 and a second end 114 connected to the second end 114 of another first member 106. Second member 108 has a third end 116 connected to a sliding member 118 on associated vertical corner support post 102 and second member 108 has a fourth end 120 connected to fourth end 120 of an associated second member 108. First end 110 and third end 116 are sometimes referred to as the outer ends of the trusses and second end 114 and fourth end 120 are sometimes referred to as the inner ends of the trusses. The above described expandable and collapsible trusses 104 are sometimes referred to as an XX-truss, double X truss, eaves, or scissor assembly. However, one of ordinary skill in the art would understand on reading this disclosure that an actual X shape is not necessary and other expandable and collapsible truss systems are possible, such as, for example, U.S. Pat. No. 5,701,923, issued to Losi et al., on Dec. 30, 1997, and incorporated herein by reference as if set out in full. Slider member 118 moves along vertical corner support post 102 from a collapsed position to an expanded position. When in the expanded position, slider member is held in place on vertical corner support post 102 using any of a number of conventional retention devices 122, such as, for example, a pin and detent or the like. As shown in FIG. 1, canopy 100 further includes an automatically deploying roof support structure. Roof support structure includes a plurality of roof support rods 124 extending from top 112 of a corresponding vertical corner support member 102 to a central hub 126. Central hub is shown as a simple connection in FIG. 1 for convenience, but details of a possible central hub are provided in FIG. 5. As shown, roof support rod 124 folds about hinge 128 to allow roof support rod 124 to fold and unfold into the collapsed and expanded positions. As explained in the '635 patent, roof support rods 124 may be designed as telescopic members as a matter of design choice. A plurality of cantilever support arms 130 extend from slider member 118 to roof support rods 124. Cantilever support arm 130 tends to force roof support rod 124 from the folded to the unfolded position as slider member 118 moves from the collapsed position to the expanded position. Once opened and locked in place, slider member 118 and cantilever support arm 130 tends to hold roof support rod 124 in the open, expanded configuration. Notice, cantilever support arm does not need to be directly connected to slider member 118, but could be connected to the trusses instead, for example. Canopy 100 also comprises a central truss support 132. Central truss support 132 comprises an angled first center member 134 having a first end 136 connected to second ends 120 and a second end 138 connected to hub 128. Central truss supports 132 also comprises stubs 140 (sometimes referred to as a cantilever, second center member or center member support) having first ends 142 connected to second ends 114 and second end 144 connected to the body of first center member 134. Roof support rods 124, central truss supports 132, and hub 126 connections are explained in more detail in FIGS. 5A and 5B, below. As one of ordinary skill in the art would recognize on reading this disclosure, the above connections generally relate to pivotal connections. Pivotal connections for instant canopies are well known in the art and generally not further explained herein. As can be appreciated on reading the disclosure, the central truss support 132 provides increased structural support against lateral forces on the middle of the expandable, collapsible trusses 104 (sometimes referred to as eaves in the art). Moreover, the roof support rods 124 in combination with the central truss support 132 provide increased support for the shell draped over canopy 100 (not shown in FIG. 1), sometimes referred to as the canopy cover. Additionally, using roof support rods 124 in combination with central truss support 132 provides more horizontal support for the shell to decreasing the droop of the shell providing a aesthetically pleasing look. Finally, because central truss support 132 comprises an angled first center member 134 and a stub 140, the headroom under the shell is not compromised toward a center 150 of the canopy area. Referring now to FIG. 2, a cross-section of canopy 100 is provided along line 2-2 of FIG. 1. Cross-section 2-2 is taken along the diagonal of canopy 100. As better shown in FIG. 2, roof support rods 124 are pivotally connected to tops 112 of vertical corner support posts 102 and pivotally connected to hub 126. Further, roof support rods 124 fold about hinges 128 to allow roof support rods 124 to be arranged in both the expanded state as shown and a collapsed state as is generally known in the art. Slider member 118 slidably connects to vertical corner support post 102 and may be locked in the expanded position (shown) using a button latch 202. Cantilever support arms 130 pivotally connect to slider member 118 and pivotally connect to roof support rod 124, which may coincide with hinges 128. Cantilever support arms may be detachable from roof support rods 124 as a matter of design choice. Also shown in FIG. 2 is a shell or canopy cover 204 draped over canopy frame 100. While shown in a loose fitting configuration, shell 204 may be drawn taut. Referring now to FIGS. 5A and 5B, central hub 126 is shown in more detail. FIG. 5A shows central hub 126 in the erect or expanded state and FIG. 5B shows central hub 126 in the collapsed state. Central hub 126 comprises a roof support rod connection 502, which is shown as having a dome top 504 to press against the shell. Roof support rod connection 502 is pivotally coupled to each roof support rod 124. A vertical roof support post 506 extends opposite dome top 504 to a central truss support connection 508. Central truss support connection 508 is pivotally connected to each central truss support 132. The pivotal connections are generally as known in the art and will not be explained herein. Central truss support connection 508 has a bore 510. In the erect state, roof support rod connection 502 and central truss support connection 508 are spaced apart a distance D. In the collapsed state, roof support rod connection 502 is collapsed toward central truss support 508 and vertical roof support post 506 moves through bore 510 and resides below central truss support connection 508. Roof support rods 124 and central truss support 132 is not labeled in FIG. 5B for convenience. The roof support rods and central truss rods may be connected to the central hub using any number of pivotal connections as is generally known in the art. For example, a flanged part 550 may have two panels 551. One panel 551 is pivotally connected to central truss support connection 508 using a pin 552 or the like. The other panel 551 is pivotally connected to central truss support 132 using a pin 552 or the like. The previous description of the disclosed embodiment is provided to enable any person skilled in the art to make or use the technology of the present application. Various modifications to the embodiment will be readily apparent to those skilled in the art on reading the disclosure, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
|
E
|
E04
|
E04H
|
15
|
50
|
|||
11769207
|
US20080149345A1-20080626
|
SMART ACTUATION MATERIALS TRIGGERED BY DEGRADATION IN OILFIELD ENVIRONMENTS AND METHODS OF USE
|
ACCEPTED
|
20080612
|
20080626
|
[]
|
E21B4300
|
["E21B4300"]
|
8485265
|
20070627
|
20130716
|
166
|
376000
|
98919.0
|
ANDREWS
|
DAVID
|
[{"inventor_name_last": "Marya", "inventor_name_first": "Manuel", "inventor_city": "Pearland", "inventor_state": "TX", "inventor_country": "US"}, {"inventor_name_last": "Bhavsar", "inventor_name_first": "Rashmi", "inventor_city": "Houston", "inventor_state": "TX", "inventor_country": "US"}]
|
Downhole devices including degradable materials and methods of using such devices to control downhole operations are disclosed. A method for controlling a downhole operation includes providing a device that includes a degradable material downhole; and degrading the degradable material to activate the device. Activation of the device may result in a displacement or flow (actuators) that may be used to control or monitor (sensor) a downhole oilfield operation. A downhole device for use in a well penetrating a formation includes, in part or in whole, a degradable material.
|
1. A method for controlling a downhole operation, comprising: providing a device downhole, wherein the device comprises a degradable material; and degrading the degradable material to actuate the device. 2. The method of claim 1, wherein the degradable material is at least partially metallic. 3. The method of claim 1, wherein the degrading of the degradable material results in a displacement of at least one selected from the following; a solid object and a flow of a fluid. 4. The method of claim 3, wherein the displacement or the flow is used to activate a secondary actuation that is at least one selected from the following; electric, magnetic, electronic, acoustic, photonic, and a combination thereof. 5. The method of claim 1, wherein the degrading of the degradable material is by contacting with a fluid. 6. The method of claim 5, wherein the fluid is at least one selected from the following; liquid, gaseous, and multi-phase. 7. The method of claim 5, wherein the fluid is one selected from the group consisting of water, seawater, an acid, brine, and a combination thereof. 8. The method of claim 1, wherein the degrading is initiated by changing at least one of the following; temperature, pressure, fluid composition, and a combination thereof. 9. The method of claim 1, wherein the degradable material comprises a metal selected from the following; calcium, magnesium, aluminum, and an alloy thereof. 10. The method of claim 1, wherein the degradable material comprises a protective coating to deter the degradation of the degradable material. 11. The method of claim 10, wherein the degrading is initiated by removal of at least part of the protective coating. 12. The method of claim 11, wherein the removal of at least part of the protective coating is initiated by at least one of the following: impact of an object, a perforating operation and a stimulation operation, thereby breaking the protective coating to expose the degradable material. 13. The method of claim 1, wherein the device is part of a downhole tool. 14. The method of claim 13, wherein the downhole tool is at least one selected from the following; a packer element, an expendable tool, and a restraining element. 15. The method of claim 1, wherein the device at least partially comprises a sensor. 16. The method of claim 1, wherein the device comprises alternate layers of the degradable material and a coating material, wherein the coating material is configured to slow down degradation of the degradable material so that the actuating material may be useful more than a single time. 17. A downhole device for use in a well penetrating a formation, wherein the downhole device comprises a degradable material. 18. The downhole device of claim 17, wherein the downhole device is one selected from the group consisting of a perforating gun, a slotted liner, a shaped charge, and proppants. 19. The downhole device of claim 17, wherein the degradable material is one selected from the group consisting of a metal, an alloy, a composite comprising the metal, and a composite comprising the alloy. 20. The downhole device of claim 19, wherein the degradable material comprises at least one selected from the group consisting of calcium, magnesium, aluminum, and alloy thereof. 21. The downhole device of claim 17, wherein the downhole device entirely comprises the degradable material. 22. The downhole device of claim 17, wherein the downhole device further comprises a coating over the degradable material to deter the degradation.
|
<SOH> BACKGROUND <EOH>In a variety of subterranean and wellbore environments, tools of all sorts are deployed for a multitude of critical applications. The tools, referred as downhole tools, may comprise subsurface safety valves, flow controllers, packers, gas lift valves, sliding sleeves as well as a great many other tools and accessories. Many of these tools have relatively complex mechanical designs in order to be controlled remotely from the surface; e.g. the rig floor via wirelines, hydraulic lines, or coil tubings. FIG. 1 shows a conventional downhole tool controller system 10 , which includes a controller 12 and a signal source 14 . Signal source 14 is shown located at or near the surface, but may be placed in any convenient location in or around a well 16 . In the embodiment shown, controller 12 is conveyed into well 16 by a tubing 18 . The downhole portion of downhole tool controller system 10 may be conveyed by other means, such as a wireline or coiled tubing. A downhole tool 20 is shown in proximity to controller 12 , but may be variously located in well 16 . Signal source 14 sends signals into well 16 for controller 12 to detect. Based on the signal received, controller 12 triggers the downhole tool 20 to perform a prescribed action. Signal source 14 may create signals as pressure sequences or in other forms, such as changes in the flow rates, weights, or stress/strain. In the most common form, signal source 14 creates pressure signals to control the downhole tool 20 via the controller 12 . When such hydraulic control is employed, the pressure pulse may be sent via dedicated hydraulic control lines. However, due to the restricted space of the wellbore, the number of control lines that can be run in a well is greatly limited. Attempts have been made to increase the number of tools that each hydraulic control line can control by using multiplexers, electric/solenoid controlled valves or custom-designed hydraulic devices and tools that respond to sequences of pressure pulses. For example, U.S. Pat. No. 7,182,139 issued to Rayssiguier et al. discloses a method that uses predetermined pressure levels to independently actuate specific well tools such that the number of well tools independently controlled may be greater than the number of fluid control lines. U.S. Pat. No. 7,171,309 issued to Goodman improves upon the reliability of such approaches by using autocorrelation of command sequences. In accordance with this method, repeat signals of a priori unknown or undefined shape can be correlated to themselves to reliably distinguish intentional changes from random fluctuations or other operations performed on the well. While these methods are useful in providing sophisticated controls of downhole tools, it is desirable to have controls that do not rely on the limited number of control lines. Furthermore, in many situations, a downhole tool may only need to be actuated once and be left alone. In such situations, the control or actuation mechanism may be more conveniently imbedded in the tool itself.
|
<SOH> SUMMARY <EOH>In one aspect, the present application relates to methods for controlling and/or sensing (monitoring) a downhole operation. A method in accordance with one embodiment includes providing a device downhole, wherein the device comprises at least one smart degradable material; and degrading the smart degradable material to activate the device. The smart degradable materials may be reactive metals and/or alloys of calcium, magnesium, or aluminum, or composites that include these metals and/or alloys in combination with non-metallic materials such as plastics, elastomers, and ceramics. The degradation of the smart degradable material in fluids (which may be referred to as “active fluids”), such as water, results in at least one response, such as a displacement for a solid object (e.g. a spring) or a flow for a fluid, that may itself be used to trigger other responses, for example the opening or closure of a device that may be electric, magnetic, electronic, acoustic, photonic, or a combination thereof. Therefore, a device and part of devices incorporating smart degradable materials may be considered as an “actuator” and, if used to convey any sort of signal for communication and information purposes, they may be used as “sensor and monitoring devices for downhole operations.” The smart degradable material may also be used as restraining element for a variety of downhole tools. In another aspect, the present invention relates to the use of these smart materials in downhole devices for applications such as penetrating a formation. A downhole device in accordance with embodiments of the invention comprises a degradable material, which may be degraded to irreversibly change the device from state “A” to state “B.” The degradable materials may be partially metallic, as in cases of composites (e.g. metal-matrix composites, or epoxy-metal composites), or fully metallic as in cases of metals (e.g. calcium metal) and alloys (e.g. calcium alloys). The degradation may occur in part of the device or throughout the entire device. Such device may be any downhole devices, which may be as small as a proppant (gravel), or as large as an entire tool (e.g. perforated tubulars or liners). Thus, part of the well completion may be degradable, which may be useful when abandoning well. In this case, the degradable tubulars and liners may be activated to degrade without requiring a recovery operation. Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
|
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims, under 35 U.S.C. § 119(e), the benefits of U.S. Provisional Patent Application No. 60/870,859 filed on Dec. 20, 2006. This Provisional Application is incorporated by reference in its entirety. This application is related to a co-pending application (Schlumberger Attorney Docket No. 68.0691NP1), entitled “Temporary Containments For Swellable Packer Elements,” by Marya et al., filed on the same date as the present application. FIELD OF THE APPLICATION The invention relates to materials for downhole applications that are considered to be smart because they can be degraded with minimal intervention and/or in a controlled manner to actuate or activate a variety of responses through the displacement of a solid element or the flow of a fluid. Particularly, the invention relates to the use of such smart materials to remotely control oilfield operations and/or sense (monitor) downhole environmental changes. BACKGROUND In a variety of subterranean and wellbore environments, tools of all sorts are deployed for a multitude of critical applications. The tools, referred as downhole tools, may comprise subsurface safety valves, flow controllers, packers, gas lift valves, sliding sleeves as well as a great many other tools and accessories. Many of these tools have relatively complex mechanical designs in order to be controlled remotely from the surface; e.g. the rig floor via wirelines, hydraulic lines, or coil tubings. FIG. 1 shows a conventional downhole tool controller system 10, which includes a controller 12 and a signal source 14. Signal source 14 is shown located at or near the surface, but may be placed in any convenient location in or around a well 16. In the embodiment shown, controller 12 is conveyed into well 16 by a tubing 18. The downhole portion of downhole tool controller system 10 may be conveyed by other means, such as a wireline or coiled tubing. A downhole tool 20 is shown in proximity to controller 12, but may be variously located in well 16. Signal source 14 sends signals into well 16 for controller 12 to detect. Based on the signal received, controller 12 triggers the downhole tool 20 to perform a prescribed action. Signal source 14 may create signals as pressure sequences or in other forms, such as changes in the flow rates, weights, or stress/strain. In the most common form, signal source 14 creates pressure signals to control the downhole tool 20 via the controller 12. When such hydraulic control is employed, the pressure pulse may be sent via dedicated hydraulic control lines. However, due to the restricted space of the wellbore, the number of control lines that can be run in a well is greatly limited. Attempts have been made to increase the number of tools that each hydraulic control line can control by using multiplexers, electric/solenoid controlled valves or custom-designed hydraulic devices and tools that respond to sequences of pressure pulses. For example, U.S. Pat. No. 7,182,139 issued to Rayssiguier et al. discloses a method that uses predetermined pressure levels to independently actuate specific well tools such that the number of well tools independently controlled may be greater than the number of fluid control lines. U.S. Pat. No. 7,171,309 issued to Goodman improves upon the reliability of such approaches by using autocorrelation of command sequences. In accordance with this method, repeat signals of a priori unknown or undefined shape can be correlated to themselves to reliably distinguish intentional changes from random fluctuations or other operations performed on the well. While these methods are useful in providing sophisticated controls of downhole tools, it is desirable to have controls that do not rely on the limited number of control lines. Furthermore, in many situations, a downhole tool may only need to be actuated once and be left alone. In such situations, the control or actuation mechanism may be more conveniently imbedded in the tool itself. SUMMARY In one aspect, the present application relates to methods for controlling and/or sensing (monitoring) a downhole operation. A method in accordance with one embodiment includes providing a device downhole, wherein the device comprises at least one smart degradable material; and degrading the smart degradable material to activate the device. The smart degradable materials may be reactive metals and/or alloys of calcium, magnesium, or aluminum, or composites that include these metals and/or alloys in combination with non-metallic materials such as plastics, elastomers, and ceramics. The degradation of the smart degradable material in fluids (which may be referred to as “active fluids”), such as water, results in at least one response, such as a displacement for a solid object (e.g. a spring) or a flow for a fluid, that may itself be used to trigger other responses, for example the opening or closure of a device that may be electric, magnetic, electronic, acoustic, photonic, or a combination thereof. Therefore, a device and part of devices incorporating smart degradable materials may be considered as an “actuator” and, if used to convey any sort of signal for communication and information purposes, they may be used as “sensor and monitoring devices for downhole operations.” The smart degradable material may also be used as restraining element for a variety of downhole tools. In another aspect, the present invention relates to the use of these smart materials in downhole devices for applications such as penetrating a formation. A downhole device in accordance with embodiments of the invention comprises a degradable material, which may be degraded to irreversibly change the device from state “A” to state “B.” The degradable materials may be partially metallic, as in cases of composites (e.g. metal-matrix composites, or epoxy-metal composites), or fully metallic as in cases of metals (e.g. calcium metal) and alloys (e.g. calcium alloys). The degradation may occur in part of the device or throughout the entire device. Such device may be any downhole devices, which may be as small as a proppant (gravel), or as large as an entire tool (e.g. perforated tubulars or liners). Thus, part of the well completion may be degradable, which may be useful when abandoning well. In this case, the degradable tubulars and liners may be activated to degrade without requiring a recovery operation. Other aspects and advantages of the invention will be apparent from the following description and the appended claims. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows a conventional control system disposed in a wellbore. FIG. 2 shows a schematic illustrating the use of a smart degradable material in the control of an action in accordance with embodiments of the invention. FIG. 3 shows a production system disposed in a producing well. FIG. 4 shows a control device using a spring and a smart degradable material in accordance with one embodiment of the invention. FIG. 5 shows a schematic illustrating a sensor comprising a smart degradable material in accordance with one embodiment of the invention. FIG. 6 shows a downhole tubing or casing having holes temporarily plugged by degradable plugs in accordance with one embodiment of the invention. FIG. 7A and FIG. 7B show charts illustrating how temperature and pH may be used to control degradation of a smart material in accordance with one embodiment of the invention. FIG. 8 shows a multiple use control in accordance with one embodiment of the invention. FIG. 9 shows a flow chart illustrating a method in accordance with one embodiment of the invention. DETAILED DESCRIPTION In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible without departing from the scope of the invention. Embodiments of the invention relate to materials that may be characterized as smart actuation materials, because they can be degraded or converted from one state to another with minimal intervention or in a controlled manner. Furthermore, because some of these materials may also exhibit the typical, high strength of metals and alloys, their conversion from one “strong and solid” state (or phase) to a degraded state (or phase) may be accompanied by a considerable change in force, pressure, stress/pressure containment, allowing the release of strongly energized mechanism or fluid flows. Therefore, such smart degradable materials may be used in downhole tools to control and/or sense (monitor) oilfield operations. The smart degradable materials of the invention may be used to make devices that are intended for a limited term use, i.e. such devices can be degraded after the intended use without the need to retrieve them from the well through time-consuming and costly “fishing” operations. The materials of this invention may be considered “debris-free” and harmless to the well environment. The “degradation” as used herein refers to any process that converts a smart material from a first state to a second state that is degraded. The “degradation” may be in the form of dissolution, disintegration or defragmentation, even occasionally swelling, and though not encountered, hypothetically shrinkage. Swelling refers to a volumetric expansion that is caused by a reaction between the smart material and the active fluid when the reaction product is a new material of greater volume that normally adheres to the surface of the smart material. Shrinkage would describe the opposite situation, wherein the interaction between the smart material and the active fluid is a new material of smaller volume (shrinkage is not to be confused with dissolution or mass loss in the fluid). Regardless of the form of degradation (e.g. weight losses, geometric changes), the result is a displacement, in one or several directions, that may be used to activate a variety of responses, including the release of an energized element and/or the release of a pressure thus causing a flow. These responses may be used to control and/or sense (monitor) oilfield operations. In accordance with some embodiments of this invention, the mechanical response produced by degrading the smart degradable material may itself be used to actuate other responses, for example the opening or closure of a device that may be electric, magnetic, electronic, acoustic, photonic, or a combination thereof. The fact that the degradable materials may be at least partially metallic, if not entirely metallic and therefore of relatively high strengths, opens a whole new range of possibilities for downhole oilfield operations without the need for more wireline or hydraulic controls. Smart as used herein refers to materials that can alter their properties, including mechanical and/or rheological properties (such as shape, stiffness, and viscosity), or thermal, optical, or electromagnetic properties, in a predictable or controllable manner in response to changes in their environment (e.g. temperature, pressure/stress and composition). Common smart materials that perform sensing and actuating functions include piezoelectries, electrostrictors, magnetostrictors, and shape-memory alloys. Shape-memory alloys may be thermoresponsive alloys (i.e. alloys that can hold different shapes at various temperatures), magnetic shape memory alloys (i.e. alloys that change their shape in response to a significant variation in the magnetic field), or, less-commonly found, pH-sensitive materials, such as polymers (i.e. materials that swell/collapse when the pH of the surrounding media changes). Other smart materials are halochromic as they change their color as a result of changing acidity (pH). Others are chromogenic and hence change color in response to electrical, optical or thermal changes. Though many smart materials are reversible, smart materials do not necessarily have to be reversible, i.e., changing state (or phase) from an initial state (or phase) to the next and returning to their initial state (or phase). The materials of this invention are smart and change state (or phase) from a solid, characterized by high strengths like in metals and alloys, to a degraded state (or phase), and this change in state (or phase) may be reversible. In accordance with embodiments of the invention, such smart (degradable) materials may be metals, alloys, or composites of metals and alloys that may include non-metallic materials, such as polymer, plastics, other organic materials (e.g. pasty fluids), or ceramics. In accordance with some embodiments of the invention, the smart materials, comprising degradable metals or alloys, may possess the strength and pressure containing capabilities needed in oilfield operations, such as when strongly energized mechanisms or significant downhole fluid pressures are needed. Due to superior mechanical properties and strength, the smart metal or alloy materials of the invention may be able to provide very rapid responses, which are not possible with typical plastics and elastomers, particularly at downhole temperatures from 200 to 450° F. The smart materials in accordance with embodiments of the invention are selected for their ability to degrade under predetermined conditions and may be made of, for example, relatively safe and reactive metals such as calcium, magnesium, and their alloys, as well as some less reactive metals like aluminum that may be made more reactive due to alloying, processing, nanoscale structures or inoculation. The materials, when they are composites, may be partially metallic, plastic, polymeric, or others, but preferably comprise at least one degradable material that is metallic by nature. The smart materials useful to the invention are not limited to these examples, and may incorporate other materials that may have adequate mechanical strength and pressure burst or collapse resistance for the designated oilfield applications, while they can be activated or degraded in a controlled manner. In addition, the smart materials in accordance with some embodiments of the invention may be covered with “permeable” coatings to retard the degradation, resulting in slow or delayed activation of the degradable material. Such “permeable” materials, which may be employed to retard the degradation of the smart materials, could be non-metallic; e.g. a porous or foamed rubber or plastic. In accordance with some embodiments of the invention, a totally impermeable layer may be used to coated and protect the smart materials. Such protective coating is removed when degradation of the smart materials is desired. For example, in perforating and similar applications, the presence of perforating jets may be used to activate the degradation by damaging such protective coatings. Once the protective coating is impaired, full degradation of the smart materials may ensue, for example, by contacting with the fluids (activation fluid) in the environments. In this example, it should be noted that the perforating operation would take place whether the material is degradable or not. However, the use of degradable materials avoids the formation of fragments or other debris that might require removal by a supplementary intervention. With smart degradable materials, the removal or “fishing” of debris becomes unnecessary. In this respect, a smart degradable material may provide an additional guarantee of undisturbed well operation. In this example, the new material does not detrimentally impact the well operation; on the contrary, it reacts “smartly” to offer a new advantage. In accordance with embodiments of the invention, the smart materials may be used alone or in combinations. Examples of combinational use of these materials may include a composite, in which a reactive metal, alloy or a reinforced metal or alloy is used with a temporary coating to create one or multiple layers, as illustrated in FIG. 8. The coatings may be solid and they may be made of plastics or elastomers. In some examples, the coatings may simply be made of a viscous fluid (e.g. a heavy oil) or a paste that may be washed away later during operation; they may serve to delay the activation of the degradable material. In accordance with embodiments of the invention, the smart materials may not only be used to actuate once but to provide multiple actuations, and for instance enable a gradual change in response. For instance, the composite components of the degradable device illustrated in FIG. 8 have been designed to be used up to as many times as there are layers of degradable materials. In FIG. 8, the degradable device also illustrates a bending mode. The inventive idea of either stress-loading or conversely releasing stress from a multilayered composite incorporating degradable materials is not limited to a bending mode, and also extends to tension, compression, torsion, shear, and may include loads that in nature are mechanical, thermal, a combination of both, or other. In FIG. 8, the multilayer apparatus may be elastically loaded so as to return to an upper and horizontal position where a last layer becomes straight. As layers in the device of FIG. 8 disappears, the actuation force gradually changes (in this example reduces), thus potentially actuating a variety of tiered responses; e.g. a reduced output from a piezoelectric element conveying information to another tiered system. In accordance with embodiments of the invention, smart materials may be induced (activated) to degrade (i.e., dissolve, disintegrate, or both) by various mechanisms, including contact with an activation or active fluid (i.e. by nature corrosive to the material) and/or due to a change in temperature and/or pressure. The change in temperature and pressure may be provided by a source of thermal energy (i.e. the trigger of a temperature change) or mechanical energy (the results of an explosion or brief pressure spike for instance, as found in jet perforating). It should be noted that the word “activate” or “activation” is used herein with reference to what is known as “activation energy” in chemical thermodynamics. A chemical reaction or phase transformation may occur over a range of conditions. Using temperature activation as an example, only when a threshold temperature is exceeded would the reaction or transformation proceed at a substantial rate or to a substantial extent, and therefore become noticeable and useful. For examples, certain materials (e.g. calcium) of the invention degrade at extremely slow rates in neutral (pH=7) water at ambient temperature, i.e. their rates of degradation are nearly zero. As the temperature is raised (e.g., in a downhole wellbore, the temperature may be allowed to increase by equilibrating with its surrounding, as found in the absence of a cold pumped fluid from the surface), the same materials may dissolve with a rate several orders of magnitude greater than at ambient (surface) temperature. In this case, the reaction or transformation exists at both low and high temperatures. However, the reaction or transformation only becomes valuable (or usable) at a relatively high temperature (e.g., downhole temperature) where the reaction or transformation rate is significant. The materials undergoing a fast transformation (i.e. degradation) is then said to be activated. Such materials may be referred to as smart materials because they react in response to changes in its surrounding environment and with minimal intervention or no additional intervention. As noted above, the degradation of smart materials may be activated by contacts with selected active fluids, temperatures, and/or pressures. The active fluids that can be used to degrade the smart degradable materials may be solvent to the particular materials such that these materials will dissolve in the fluids. The “active fluids” may be liquid, gas, or both. The liquid-type active fluids will typically contain water, but is not so limited and may contain other liquids such as acids. The gas-type active fluids may contain any suitable gases, including as non-Limiting examples water vapor and acid vapors. Furthermore, some active fluids may be multi-phase fluids, which, for example, may have water as one constituent. Some water-based active fluids may also be comprised of an acid or a brine (e.g. some chlorides) dissolved in water, and may contain dissolved gases, such as carbon dioxide (CO2) or hydrogen sulfide (H2S), that contribute to enhancing acidity of the active fluid and, therefore, raise degradation rates. In addition to active fluids, degradation of the smart materials may also be triggered by the temperature or pressure, which may be transient (e.g., short) or sustained (e.g., prolonged). An example of a transient pressure is the pressure momentarily caused by a perforating jet of an explosion, a high-velocity abrasive fluid jet, or the impact of one object onto another. As noted above, in accordance with some embodiments of the invention, the smart materials include metals or alloys. Typical examples of smart metals and alloys in accordance with embodiments of the invention include relatively safe alkaline & alkaline-earth metals such as calcium (Ca safely dissolves in water regardless of pH), magnesium (Mg dissolves at low pH), aluminum (Al dissolves at low pH), and alloys and composites of those metals that degrade in water at rates that depend upon temperature, pressure, and fluid composition. For example, acids may accelerate the degradation of these metals or alloys. The following Table lists some examples of metal and alloy smart materials in accordance with embodiments of the invention. The Table lists metal and alloy compositions, degradation rates at normal pressure (1 atm) in water of specific pH and temperature, as well as their approximate ambient-temperature strength. As shown in this Table, an alloy of calcium containing 20 percent by weight magnesium degrades much slower than pure calcium metal (i.e., 99.99% Ca) and is also about 10 times stronger (i.e., its strength is comparable that of quenched and tempered steels). In addition, note that aluminum can be made degradable in neutral water with suitable alloying elements. Degradation Strength Temperature pH rate Material (MPa) (° C.) range (mm/h) Calcium metal ~70 25 3-11 ~5 (99.99% Ca) 65 3-11 10-11 90 3-11 17-20 Calcium alloy ~700 25 3-11 ~0.05 (Ca—20 wt. % Mg) 65 3-11 0.2-0.3 90 3-11 1.2-1.7 Aluminum metal ~100 90 7 <0.0001 (99.99Ca) Aluminum alloy ~ 90 7 ~0.17 (A1—21Ga) Aluminum alloy ~ 90 7 ~0.03 (A1—10Ga—10Mg) Aluminum alloy ~ 25 7 0.5-0.6 (A1—5Ga—5Mg—5In) 90 7 0.8-0.9 A convenient method to activate (degrade) these smart materials is to make use of the temperature change that, are typically encountered in a wellbore. As shown in the Table above, the slow, and perhaps unnoticeable, degradation rates may be enhanced by increasing temperatures. This is exemplified by the calcium alloy, the degradation rate of which is increased over 20 times by raising the temperatures from 25 to 90° C. Thus, the same reaction at a temperature of 200° C. or higher (which is likely encountered in a deep wells) may become sufficiently fast to degrade these materials (and components made at least partially of those materials) within predictable durations. In accordance with embodiments of the invention, these smart materials may be used to make smart devices for various controls, such as downhole tool controls. These devices are designed to change from state A to state B upon degradation of the smart materials from one state or phase to the following degraded state or phase. An example of changing a device from state A to state B may be found in a valve that is turned “on” from an “off” state. The use of smart materials to make smart devices would allow an operator to control the devices with limited or no external direct intervention and without control lines. All the operator needs to do is to initiate the smart material degradation process, for example, by increasing pressure (e.g., by increasing a set-down weight), and/or by addition of a degradation reagent (e.g., an acid or a brine that would accelerate the rates of degradation). Upon degradation of the smart materials, a change in the force, displacement, or the like (pressure and stress, or strain) would occur within the smart device. This in turn will result in the actuation of the device. The smart materials in accordance with embodiments of the invention may be used in various oilfield applications. The following describe several examples pertinent to downhole oil and gas recovery operations. However, one of ordinary skill in the art would appreciate that these examples are for illustration only and various variations and modifications are possible without departing from the scope of the invention. For example, embodiments of the present invention may be used in the control of flow and displacement in downhole environments. The smart materials may be used in actuators, for example, to activate other mechanisms, which may be as simple as compression springs (as used in, for example, energized packer elements or production packer slips, anchoring release devices, etc) or more complex systems (such as a variety of electronic gauges and sensors). In accordance with some embodiments of the invention, the material may itself be used as a sensor. The disappearance or compromise of integrity (e.g., due to degradation) of the smart materials could indicate the presence of a particular condition, for example, water (liquid and/or vapor) in situations where water (liquid and/or vapor) would not be expected in the well environment or in situations where the production of water would indicate the oil reservoir has been depleted, and it may be time to abandon the well. FIG. 2 shows a schematic illustrating how a smart material of the invention may function to control a device or a flow. As shown in FIG. 2A, the presence of the smart material (or degradable material) blocks the action of a force or pressure (e.g., hydraulic or mechanical force) acting on a system (e.g., a valve). FIG. 2B shows one example in which the presence of a smart material prevents fluid flow (e.g., by keeping a valve in a closed position), while FIG. 2C shows that fluid flow is possible after the smart material has been degraded. In another example, FIG. 2D shows that the presence of the smart material prevents a spring from being extended. Once the smart material is degraded, as shown in FIG. 2E, the spring extends, therefore releasing its stored elastic energy, and the force exerted by the spring may be used to cause a displacement of some parts in a device—e.g., to slide open a sleeve valve. Though FIG. 2 illustrates an example with a compression spring, the same concept of releasing energy through the degradation of a material loading a spring may also be used with other loading modes. Such modes include tension, torsion, shear and/or bending, and the element storing mechanical energy is not only limited to mechanical springs, but broadly includes any materials that is elastically or reversibly loaded; e.g. a beam placed in a bending mode. FIG. 3 shows an oil production system 30 disposed in a wellbore. As shown, a production tubing 32 is disposed in a production casing or liner 31. The production tubing 32 includes several devices: hold-down slips 33, packer elements 34, set-down slips 35, and tail pipe and lower completion components 36. Once the production tubing 32 is in place, the packer elements 34 may need to be set. To set a packer, some downhole device is activated. The activation mechanism may be as shown in FIG. 2. FIG. 4 shows one example of an actuation mechanism that uses a spring loaded mechanism, as illustrated in FIG. 2B and FIG. 2C. As shown in FIG. 4, a pivotal arm 43 is designed to engage the wellbore wall by the action of the spring 42. A device of a degradable material (smart material) 41 of the invention may be used to prevent the deployment of the pivotal arm 43 until it is time for deployment. When it is time to deploy the pivotal arm 43, the degradable material is degraded to allow the displacement of the spring 42. The force from the spring 42 will then urge the pivotal arm 43 to engage the borehole wall. The release of the pivotal arm is expected to find applications in the deployment of packer slips, or any expandable tools that need to be temporarily restrained. The degradable device 41 in FIG. 4 may be in the form of a tubular, but may take any shape provided that it fulfills the basic functions of preventing displacement and/or flow and reacts “smartly” to its environment. In accordance with some embodiments of the invention, smart materials may be used in sensors, which may be used to detect the presence of a corrosive fluid (water liquid, water vapor, etc). For example, FIG. 5 shows an electrically conductive, high-strength water-soluble smart material 51 is used to “close” a circuitry 50 of a sensor. If water is encountered by this device, the smart material will degrade, displace the active fluid (in this example) and the presence of water or other active fluid, by increasing electrical resistance (impedance) would stop the current to flow in the circuitry and therefore activate a signal generator 52. Activation of the signal generator 52 may produce a system response, which may commonly be mechanical (spring or any other displacement, or a fluid flow, as shown in FIG. 2), electrical, electronic, magnetic, acoustic, photonic, or a combination thereof. Again, this example of electrical switch depicted in FIG. 5 is made possible because of the removal of an electrically conductive degradable materials and the displacement it caused by introducing a non-conductive, or poorly conductive medium. A situation opposite to that just describe (i.e., a non-conductive material degraded by a conductive liquid) would also work. In accordance with some embodiments of the invention, the smart materials may be used with hollow components (such as liners or casing), in which the smart materials are used as degradable plugs/caps/sealing elements. FIG. 6 shows one example of a casing having a plurality of holes 61, in which degradable plugs 62 temporarily seals these hole. In one example, the smart degradable plugs may be selected according to the downhole environments, to which they will be exposed, such that the smart degradable plugs slowly disappear over time. In other examples, a protective coating may be applied on the plugs, wherein the protective coating may be compromised by an impact (such as by the side impact of a fallen object), an abrasive or an explosive jet, for instance. For example, when jet perforation is to be performed, these holes 61 may be opened by degrading the temporary plugs 62. Degradable plugs may be also useful to prevent flow though slotted liners, where pre-drilled or pre-cut holes are encountered. A liner may also look like the tubing of FIG. 6. In accordance with some embodiments of the invention, the smart materials may be used in disposable and degradable tools, such as shaped charges and perforating guns, including tools used in tubing-conveyed applications. These devices will eventually degrade in the well or formation, saving the need to retrieve these devices after use. These devices may be considered zero-debris devices and may include perforating shaped charge casings, guns, and related devices. Such degradable devices would simplify oilfield operations by eliminating the need for recovery or fishing operations. In accordance with some embodiments of the invention, the smart materials may be selected to be crush resistant for use in a fracturing fluid. These types of materials, for example, may include metals or alloy (e.g., calcium alloy, aluminum alloy), and composites of those. Such materials may be used as additives or proppants in a hydraulic fracturing fluid. Such materials may be in the shape of flakes, shots, granules and the like. Such materials can be placed in the formation fractures to momentarily increase flows. When production from that particular zone is no longer needed, these materials may be degraded to close the fractures, for instance by pumping an active fluid (e.g. an acid), and/or stopping pumping a cold fluid, and/or enabling the naturally hot reservoir temperature to return to equilibrium. As noted above, degradation of the smart materials may be by contacting selected fluids, temperatures, and/or pressures. In addition, the pH of the fluids may also be changed to degrade the smart materials in cases such material degradation rate is affected by pH, which had been seen in laboratory experiments with aluminum and magnesium alloys. With temperature and/or pressure, the materials may be so selected that the changes in temperatures and/or pressure (i.e., in typical downhole applications) would raise their degradation rates. FIGS. 7A and 7B show two charts illustrating how degradation rates (i.e., the activation of the smart materials) may be controlled by temperature (FIG. 7A) and pH (FIG. 7B). FIG. 7A shows that the smart material degradation increases exponentially with the temperature, typically following an Arrhenius-type law; i.e. the degradation is thermally activated. FIG. 7B shows that low pH values (as produced by concentrated acids in water) also increase degradation rates. An increase in degradation may also be induced by greater pressures. For example, the pressure of deep wells may increase degradation rate more than the relatively low pressures of shallow wells. The degradable materials are best suited for one-time use; however, they are not so limited. In accordance with some embodiments of the invention, certain degradable materials may function as smart actuators on a repeatable (multiple use) basis. For such multiple uses, more complex materials such as laminated or layered composites may be designed. In a laminated or layered composite, the number of layer may indicate the number of times the component can be used. Such composites may be designed to release elastic energy, or residual stresses as part of the composite degrades. FIG. 8 shows a simple example to illustrate the principle of operation of such composite materials (for illustration purpose). In FIG. 8, the light gray layers 81, 83, 85, 87 are protective layers and the dark gray layers 82, 84, 86 represent the degradable material. Note that the layered materials or composites of FIG. 8 are made of repetitive layers. In FIG. 8, the composite layers are loaded in a bending conformation. This is for illustration only (other loading conditions are possible). The composite of FIG. 8 is comprised of two materials. However, in real situations, these composites may be more complex and may comprise a variety of shapes and different materials to serve under various loading conditions. In the simple mechanism of FIG. 8, the deflection is gradually relieved as layers of the dark gray (degradable) materials are removed. Such changes in deflection may be used as activation devices, for instance a sensor having more than simple ON and OFF positions, but having a set of intermediate positions corresponding to the gradual release in deflection. The light gray layers are to delay the degradation of the dark gray layers and may be made of materials slowly absorbing the fluid of the surrounding environment (e.g. elastomers, plastics, porous ceramics, etc). FIG. 9 shows a flow chart illustrating a method for controlling a downhole operation in accordance with one embodiment of the invention. As shown in FIG. 9, a smart device is provided downhole (step 91). The smart device comprises a smart material of the invention. When a particular action is desired, the smart device is activated by degrading the smart material in the smart device (step 92). As a result of the activation, a downhole operation is performed (or stopped) (step 93). While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
|
E
|
E21
|
E21B
|
43
|
00
|
|||
11945270
|
US20080129315A1-20080605
|
DETECTING APPARATUS
|
ACCEPTED
|
20080521
|
20080605
|
[]
|
H01H3102
|
["H01H3102"]
|
7795880
|
20071127
|
20100914
|
324
|
555000
|
95936.0
|
ZHU
|
JOHN
|
[{"inventor_name_last": "ZHANG", "inventor_name_first": "BING-JUN", "inventor_city": "Shenzhen", "inventor_state": "", "inventor_country": "CN"}, {"inventor_name_last": "GONG", "inventor_name_first": "LIAN-ZHONG", "inventor_city": "Shenzhen", "inventor_state": "", "inventor_country": "CN"}]
|
A detecting apparatus for checking a detected item of an electrically conductive fastener attached to a workpiece includes a lower checking member for supporting the workpiece, an upper checking member movably set above the lower checking member, an electrical source, a processor, and an indicator. At least one of the two members includes a checking unit, which touches with the fastener and together with the fastener forms a detecting circuit when the upper checking member abuts against the workpiece. The detecting circuit is connected to the electrical source. A closed or open state of the detecting circuit indicates whether the detected item is eligible or ineligible. The processor controls the indicator to show the checking result according to the closed or open state of the detecting circuit. The detecting apparatus can greatly improve the checking efficiency and reliability, and suits mass production.
|
1. A detecting apparatus for checking at least one detected item of at least one electrically conductive fastener attached to a workpiece, comprising: a lower checking member configured to support the workpiece; an upper checking member movably set above the lower checking member; an electrical source; a processor; and an indicator; wherein at least one of the lower checking member and the upper checking member comprises at least one checking unit corresponding to the at least one detected item of the fastener, the at least one checking unit cooperates with the corresponding fastener to form a detecting circuit, the detecting circuit is connected to two electric poles of the electrical source, a closed or open state of the detecting circuit exists depending on whether the at least one checking unit touches the corresponding fastener when the upper checking member abuts against the workpiece to close the detecting circuit and indicates whether the detected item is eligible or ineligible, the processor controls the indicator to show the checking result according to the closed or open state of the detecting circuit. 2. The detecting apparatus as claimed in claim 1, wherein the checking unit comprises a elastic-element-loaded electrically conductive checking pin slidably mounted thereto, the detected item is whether the fastener is attached to the workpiece, the checking pin elastically contacts the fastener and the detecting circuit remains open if the fastener is not attached to the workpiece, or the checking pin doesn't touch with the fastener and the detecting circuit closes if the fastener is attached to the workpiece. 3. The detecting apparatus as claimed in claim 1, wherein the fastener has a cylindrical shape, the checking unit comprises an electrically conductive checking sheath, the fastener enters a column-shaped space bounded by the checking sheath when the upper checking member abuts against the workpiece, the detected item is an accuracy of linearity and/or position of the fastener, a condition of ineligible of detected item is that a value of a deflection of linearity and/or position of the fastener is not less than a allowable tolerance of the accuracy of linearity and/or position of the fastener, an axis of the column-shaped space of the checking sheath and an axis of the fastener are in line when the accuracy of linearity and/or position of the fastener is eligible, a diameter of a cross-section of the column-shaped space is longer than a diameter of a cross-section of the fastener and a difference between the diameters is equal to the allowable tolerance, if the fastener touches with the checking sheath when the fastener enters the column-shaped space of the checking sheath, the detecting circuit closes and the accuracy of linearity and/or position of the fastener is eligible, or if the fastener does not touch with the checking sheath when the fastener enters the column-shaped space of the checking sheath, the detecting circuit remains open and accuracy of linearity and/or position of the fastener is ineligible. 4. The detecting apparatus as claimed in claim 1, wherein the checking unit comprises an electrically conductive checking pin elastically restrained by an elasticity element and slidably mounted, the detected item is whether a height of the fastener is too low, a condition of ineligible of the detected item is that a value of a lacking portion the deflection of height of the fastener is more than a allowable tolerance of the height of the fastener, the checking pin touches with the fastener when the upper checking member abuts against the workpiece and the detecting circuit closes if the height of the fastener is eligible, or the checking pin doesn't touch with the fastener when the upper checking member abuts against the workpiece and the detecting circuit remains open if the height of the fastener is too low. 5. The detecting apparatus as claimed in claim 1, wherein the lower checking member consists of electrically conductive material, the lower checking member, the detecting circuit and electrical source are in the same electrical circuit. 6. The detecting apparatus as claimed in claim 5, wherein a plurality of posts is mounted at a bottom of the upper checking member configured for pressing against the workpiece. 7. The detecting apparatus as claimed in claim 6, wherein a cylinder device is mounted thereto configured to drive the upper checking member to move. 8. The detecting apparatus as claimed in claim 7, wherein the detecting apparatus further comprises a bracemounted thereto configured to hold the cylinder device, the brace comprises a L-shaped supporter and a bottom plate, the bottom plate is fixed at a bottom end of the brace and the cylinder device is mounted to another free end of the brace, the lower checking member is mounted on the bottom plate. 9. The detecting apparatus as claimed in claim 8, wherein an electric control box is set under the bottom plate of the brace, a plurality of controller buttons are set on the electric control box, the processor and the electrical source are received in the electric control box. 10. The detecting apparatus as claimed in claim 3, wherein the indicator comprises at least one of a display, an indicator light and an annunciator. 11. The detecting apparatus claimed in claim 10, wherein the detecting apparatus further comprises a safety light grid device mounting at the front of the electric control box, the safety light grid device comprising a chassis mounting to the electric control box and a light transmitter and a light receiver respectively mounted at opposite sides of the chassis, light is transmitted from the light transmitter to the light receiver across a space between the two sides of the grid device, when some part of an operator's body passes through the space to enter a working area of the detecting apparatus, the part of the body cutting off light in the space and the detecting apparatus stopping working for protecting the operator. 12. The detecting apparatus as claimed in claim 1, wherein a table is mounted under the electric control box configured for supporting the electric control box. 13. A detecting apparatus for checking whether at least one electrically conductive fastener, which should be fixed to a workpiece, is attached to the workpiece, comprising: a lower checking member configured to support the workpiece; an upper checking member movably set above the lower checking member; a processor; and an indicator; wherein at least one of the lower checking member and the upper checking member comprises at least one elastic-element-loaded checking pin slidably mounted thereto and at least one travel detector corresponding to said at least one electrically conductive fastener, the travel detector comprises a switch portion, one end of the checking pin can touch the fastener and be pushed to slide by the fastener, the other end of the checking pin can touch with and press the travel detector, the checking pin and the travel detector cooperates with the fastener form a detecting circuit, when the upper checking member abuts against the workpiece, the checking pin is pushed to slide by the fastener and press the switch portion of the travel detector and the detecting circuit closes if the fastener is attached to the workpiece, or the checking pin can not press the switch portion of the travel detector and the detecting circuit remains open if the fastener is not attached to the workpiece, the processor controls the indicator to show the checking result according to the closed or open state of the detecting circuit. 14. The detecting apparatus as claimed in claim 13, wherein a plurality of posts is mounted at a bottom of the upper checking member configured for pressing against the workpiece. 15. The detecting apparatus as claimed in claim 13, wherein the elastic-element is a spring. 16. A detecting apparatus for checking whether a height of at least one electrically conductive fastener attached to the workpiece is too high, comprising: a lower checking member configured to support the workpiece; an upper checking member movably set above the lower checking member; an electrical source; a processor; and an indicator; wherein at least one of the lower checking member and the upper checking member comprises at least one elastic-element-loaded checking pin slidably mounted thereto and at least one elastic-element-loaded checking block slidably mounted thereto corresponding to said at least one electrically conductive fastener, one end of the checking pin can touch the fastener and be pushed to slide by the fastener, the other end of the checking pin can touch the checking block, the checking pin and the checking block together with the fastener cooperatively form a detecting circuit, the detecting circuit is connected to two electric poles of the electrical source, when the upper checking member abuts against the workpiece, the checking pin is propped up to slide by the fastener and touch the checking block and the detecting circuit closes if height of the fastener is too high, or the checking pin doesn't touch the checking block and the detecting circuit remains open if height of the fastener is not too high, the processor controls the indicator to show the checking result according to the closed or open state of the detecting circuit. 17. The detecting apparatus as claimed in claim 16, wherein a plurality of posts is mounted at a bottom of the upper checking member configured for pressing out the workpiece. 18. The detecting apparatus as claimed in claim 16, wherein the elastic-element is a spring.
|
<SOH> BACKGROUND <EOH>1. Field of the Invention The present invention relates to detecting apparatuses. 2. Description of Related Art On an assembly line, a mass of parts, such as fasteners installed in workpieces, may need to be checked whether they are attached to the workpieces properly. Referring to FIG. 1 , a workpiece 90 , such as a chassis of a liquid crystal display (LCD), is shown. Electrically conductive fasteners of the workpiece 90 , which need to be checked, include two first rivets 6 , three second rivets 16 , two third rivets 8 , a fourth rivet 7 , a square piece 188 , and a long piece 19 . The first rivets 6 and the second rivets 16 are very much alike, but the first rivet 6 is longer. For these fasteners, detected items include: first, checking whether the fasteners are attached to the workpiece 90 ; second, checking heights of the first rivets 6 and the second rivets 16 ; third, checking whether the first rivets 6 and the second rivets 16 are attached to the workpiece 90 at predetermined places respectively; and fourth, checking linearity and/or position of the first rivets 6 , the second rivets 16 , and the third rivet 7 . Typically, the first and third detected items are visually checked by workmen. It is time-consuming and labor-intensive for the workmen, and a long time working will easily cause eye fatigue, which leads to a low checking accuracy and a high checking error rate. This way is inefficient and unfit for mass production. Referring to FIGS. 2 and 3 , checking the heights of the first rivets 6 and the second rivets 16 is done manually by workmen using some tools, such as a height detecting tool 91 . Referring particularly to FIG. 3 , a distance between a first cantilevered portion of the height detecting tool 91 and a reference plane, dimensioned as Dmax means a maximum permitted height of a part to be checked, while a distance between a second cantilevered portion of the height detecting tool 91 and the reference place, dimensioned as Dmin means a minimum permitted height of the part. In detection, the height detecting tool 91 is advanced towards one of the rivets, such as one rivet 6 , with a bottom of the tool 91 abutting on the surface of the workpiece 90 . The surface of the workpiece 90 acts as the reference plane. If the first cantilevered portion of the tool 91 corresponding to the Dmax can pass the rivet 6 and the second cantilevered portion thereof corresponding to the Dmin can not pass the rivet 6 , a height of the rivet 6 is eligible, otherwise, the height is ineligible. Moreover, different height rivets need different height detecting tools for checking. Thus, checking rivets in this way is complex and labor-intensive for the workmen, and it is inefficient and unfit for mass production. A detecting tool 92 shown in FIG. 4 is commonly used for checking the accuracy of linearity and/or position of the first rivets 6 , the second rivets 16 , and the third rivet 7 . In use, the workman grips a handle of the tool 92 , and moves the tool 92 to the workpiece 90 to see whether the first rivets 6 , the second rivets 16 , and the third rivet 7 can enter corresponding detecting holes defined in the tool 92 . If each rivet enters the corresponding detecting hole smoothly, the linearity and/or position of the rivet is eligible; otherwise, it is ineligible. Checking in this way, it's hard for the workman to align the checking holes of the tool 92 with the rivets of the workpiece 90 , and the tool 92 may accidently bump the rivets in aligning process. Moreover, it is hard for the workman to judge contact between a number of walls bounding the corresponding holes and corresponding rivets, which seriously affects a detecting accuracy. What is desired, therefore, is a detecting apparatus suitable for use in mass production environment, which improves checking efficiency and reliability.
|
<SOH> SUMMARY <EOH>An exemplary detecting apparatus for checking at least one detected item of at least one electrically conductive fastener attached to a workpiece, includes a lower checking member configured to support the workpiece, an upper checking member movably set above the lower checking member, an electrical source, a processor, and an indicator. At least one of the lower checking member and the upper checking member comprises at least one checking unit corresponding to the at least one detected item of the fastener. The at least one checking unit can cooperate with the corresponding fastener to form a detecting circuit. The detecting circuit is connected to two electric poles of the electrical source. A closed or open state of the detecting circuit exists depending on whether the at least one checking unit touches the corresponding fastener when the upper checking member abuts against the workpiece to close the detecting circuit, and indicates whether the detected item is eligible or ineligible. The processor controls the indicator to show the checking result according to the closed or open state of the detecting circuit. Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:
|
BACKGROUND 1. Field of the Invention The present invention relates to detecting apparatuses. 2. Description of Related Art On an assembly line, a mass of parts, such as fasteners installed in workpieces, may need to be checked whether they are attached to the workpieces properly. Referring to FIG. 1, a workpiece 90, such as a chassis of a liquid crystal display (LCD), is shown. Electrically conductive fasteners of the workpiece 90, which need to be checked, include two first rivets 6, three second rivets 16, two third rivets 8, a fourth rivet 7, a square piece 188, and a long piece 19. The first rivets 6 and the second rivets 16 are very much alike, but the first rivet 6 is longer. For these fasteners, detected items include: first, checking whether the fasteners are attached to the workpiece 90; second, checking heights of the first rivets 6 and the second rivets 16; third, checking whether the first rivets 6 and the second rivets 16 are attached to the workpiece 90 at predetermined places respectively; and fourth, checking linearity and/or position of the first rivets 6, the second rivets 16, and the third rivet 7. Typically, the first and third detected items are visually checked by workmen. It is time-consuming and labor-intensive for the workmen, and a long time working will easily cause eye fatigue, which leads to a low checking accuracy and a high checking error rate. This way is inefficient and unfit for mass production. Referring to FIGS. 2 and 3, checking the heights of the first rivets 6 and the second rivets 16 is done manually by workmen using some tools, such as a height detecting tool 91. Referring particularly to FIG. 3, a distance between a first cantilevered portion of the height detecting tool 91 and a reference plane, dimensioned as Dmax means a maximum permitted height of a part to be checked, while a distance between a second cantilevered portion of the height detecting tool 91 and the reference place, dimensioned as Dmin means a minimum permitted height of the part. In detection, the height detecting tool 91 is advanced towards one of the rivets, such as one rivet 6, with a bottom of the tool 91 abutting on the surface of the workpiece 90. The surface of the workpiece 90 acts as the reference plane. If the first cantilevered portion of the tool 91 corresponding to the Dmax can pass the rivet 6 and the second cantilevered portion thereof corresponding to the Dmin can not pass the rivet 6, a height of the rivet 6 is eligible, otherwise, the height is ineligible. Moreover, different height rivets need different height detecting tools for checking. Thus, checking rivets in this way is complex and labor-intensive for the workmen, and it is inefficient and unfit for mass production. A detecting tool 92 shown in FIG. 4 is commonly used for checking the accuracy of linearity and/or position of the first rivets 6, the second rivets 16, and the third rivet 7. In use, the workman grips a handle of the tool 92, and moves the tool 92 to the workpiece 90 to see whether the first rivets 6, the second rivets 16, and the third rivet 7 can enter corresponding detecting holes defined in the tool 92. If each rivet enters the corresponding detecting hole smoothly, the linearity and/or position of the rivet is eligible; otherwise, it is ineligible. Checking in this way, it's hard for the workman to align the checking holes of the tool 92 with the rivets of the workpiece 90, and the tool 92 may accidently bump the rivets in aligning process. Moreover, it is hard for the workman to judge contact between a number of walls bounding the corresponding holes and corresponding rivets, which seriously affects a detecting accuracy. What is desired, therefore, is a detecting apparatus suitable for use in mass production environment, which improves checking efficiency and reliability. SUMMARY An exemplary detecting apparatus for checking at least one detected item of at least one electrically conductive fastener attached to a workpiece, includes a lower checking member configured to support the workpiece, an upper checking member movably set above the lower checking member, an electrical source, a processor, and an indicator. At least one of the lower checking member and the upper checking member comprises at least one checking unit corresponding to the at least one detected item of the fastener. The at least one checking unit can cooperate with the corresponding fastener to form a detecting circuit. The detecting circuit is connected to two electric poles of the electrical source. A closed or open state of the detecting circuit exists depending on whether the at least one checking unit touches the corresponding fastener when the upper checking member abuts against the workpiece to close the detecting circuit, and indicates whether the detected item is eligible or ineligible. The processor controls the indicator to show the checking result according to the closed or open state of the detecting circuit. Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded, isometric view of a workpiece, together with electrically conductive fasteners which need to be checked; FIG. 2 is an isometric view of a typical height detecting tool checking a height of a fastener of the workpiece; FIG. 3 is a side, elevational view of FIG. 2; FIG. 4 is an isometric view of a typical detecting tool used for checking accuracy of linearity and/or position and the workpiece; FIG. 5 is an isometric view of a detecting apparatus in accordance with an embodiment of the present invention; FIG. 6 is an exploded, isometric view of FIG. 5; FIG. 7 is an electrical schematic of the present invention; FIG. 8 is a partial cut-away view of the detecting apparatus in operation and the workpiece of FIG. 1, showing the fasteners being eligible; FIG. 9 is an enlarged view of a circled portion IX of FIG. 8; FIG. 10 is similar to FIG. 8, without the fasteners in place; FIG. 11 is similar to FIG. 8, showing accuracies of linearity and/or position of the fasteners being ineligible; FIG. 12 is similar to FIG. 8, showing heights of the fasteners being too high; and FIG. 13 is similar to FIG. 8, showing heights of the fasteners being too low. DETAILED DESCRIPTION Referring to FIGS. 5 and 6, a detecting apparatus in accordance with an embodiment of the present invention includes an electric control box 50, a table 20 for supporting the electric control box 50, a brace 60 mounted on the box 50, a safety light grid device 30 mounted at the front of the box 50, a lower checking member 10 mounted on a bottom plate 62 of the brace 60, a cylinder device 68 fixed to the brace 60, and an upper checking member 80 fixed to the cylinder device 68 and suspended over the lower checking member 10. A display 42, an indicator light 44, and a plurality of controller buttons 52 are set at the front of the electric control box 50. An electrical source (not shown) and a processor 100 (see FIG. 7) are set in the box 50. The table 20 includes four wheels attached thereto for facilitating moving the detecting apparatus. The brace 60 includes an L-shaped supporter 64. The bottom plate 62 is fixed at a bottom of the supporter 64. A visible or audible alarm apparatus, such as an alarm annunciator 46, set on a top of the supporter 64. A hole, over which the lower checking member 10 is set, is defined in the bottom plate 62. The display 42, the indicator light 44, and the annunciator 46 make up an indicator of the embodiment. The safety light grid device 30 includes a chassis 32 mounted to the electric control box 50, and a light transmitter 341 and a light receiver 342 respectively mounted at opposite sides of the chassis 32. The light transmitter 341 and the light receiver 342 are connected to an on-off circuit of the detecting apparatus. Light is transmitted from the light transmitter 341 to the light receiver 342 across a space between the two sides of the grid device 30. When some part of an operator's body passes through the space to enter a working area of the detecting apparatus, the part of the body will cut off light between the light transmitter 341 and the light receiver 342, which causes the detecting apparatus to stop thereby protecting the operator. Referring also to FIG. 8, the lower checking member 10 designed according to a shape of the workpiece 90 includes a board 11 made of electrically conductive material, at least one fixing block 12 made of electrically insulative material and fixed at a bottom of the board 11, at least one steel checking sheath 13 correspondingly set in the fixing block 12, at least one spring-loaded checking pin 14 slidably mounted in the board 11, and at least one travel detector 15 fixed at the bottom of the board 11, and placed under the checking pin 14. A first end of a wire E is connected to the board 11, and a second end of the wire E is connected to the electrical source in the electric control box 50. A first end of a wire F is connected to the checking sheath 13, and a second end of the wire F is connected to the electrical source. The upper checking member 80, which is box-shaped and driven by the cylinder device 68 to move in an up-and-down direction, includes a base 81 made of electrically insulative material, a plurality of posts 5 mounted at a bottom of the base 81 for pressing against the workpiece which is placed on the lower checking member 10. At least one spring-loaded checking pin 9 is slidably mounted at the bottom of the base 81. At least one steel checking-sheath 4 is mounted in a bottom portion of the base 81, and at least one steel fixing sheath 18 is mounted in a top portion of the base 81 corresponding to the checking sheath 4. At least one spring-loaded checking pin 2 is slidably extended through the base 81 via the fixing sheath 18 and correspondingly through a column-shaped space defined in the checking sheath 4. At least one spring-loaded checking block 1 is slidably mounted on the base 81 above the corresponding at least one checking pin 2. The posts 5, the checking pin 9, the checking sheath 4, the fixing sheath 18, the checking pin 2, and the checking block 1 are all made of electrically conductive material. A first end of a wire A is connected to the checking pin 2, a first end of a wire B is connected to the checking block 1, a first end of a wires C is connected to the checking sheath 4, and a first end of a wire D is connected to the checking pin 9. Second ends of wires A, B, C and D are connected to the electrical source in the electric control box 50. Referring to FIG. 7, an electrical schematic of the present invention is shown. Signals, which are used to send orders to the processor 100 to start or stop the working of the detecting apparatus, can be transmitted from the safety light grid device 30 and the buttons 52 to the processor 100. A signal, which is used to control the cylinder device 68 to move up and down, is transmitted from the processor 100 and the buttons 52 to the cylinder device 68. The upper checking member 80 is driven by the cylinder device 68 to move towards or away from the lower checking member 10. Detecting circuits (see below) are monitored by the processor 100 when the upper checking member 80 moves towards the lower checking member 10. The processor 100 detects closed or open states of the detecting circuits, and then sends signals to the indicator made up of the display 42, the indicator light 44, and the annunciator 46. In what follows, one first rivet 6, one third rivet 8, and one fourth rivet 7 are taken as examples for describing the working principle of the detecting apparatus in accordance with the embodiment. Referring to FIG. 10, and comparing FIG. 10 with FIG. 8, FIG. 8 shows that the detected items of the first rivet 6, the third rivet 8 and the fourth rivet 7 are eligible with zero-deviation, while FIG. 10 shows a state that the first rivet 6, the third rivet 8 and the fourth rivet 7 are not attached to the workpiece 90. The workpiece 90 is placed on the lower checking member 10. The upper checking member 80 driven by the cylinder device 68 moves down until its posts 5 just press on the workpiece 90. For the fourth rivet 7, if it is attached to the workpiece 90 as shown in FIG. 8, the checking pin 9 will be stopped by the fourth rivet 7 and pushed to move upward relatively to the upper checking member 80 with a spring around the checking pin 9 compressed, a detecting circuit including the checking pin 9 and the fourth rivet 7 closes, and current flows from the electrical source through the wire D, the checking pin 9, the fourth rivet 7, the workpiece 90, the lower checking member 10, the wire E, and back to the electrical source. The processor 100 receives a circuit closed signal and controls the indicator to indicate that the fourth rivet 7 is attached to the workpiece 90; otherwise, if the fourth rivet 7 is not attached to the workpiece 90, the checking pin 9 moves downward with the upper checking member 80, and enters a mounting hole for the fourth rivet 7 without contacting with the workpiece 90, and the detecting circuit including the checking pin 9 and the fourth rivet 7 remains open and the processor 100 registers that the detecting circuit is open and controls the indicator to indicate that the fourth rivet 7 is not attached to the workpiece 90. For the fourth rivet 8, if it is attached to the workpiece 90, the checking pin 14 is pressed by the fourth rivet 8 and moves downward with a spring around the checking pin 14 compressing, until it presses and activates a switch of the travel detector 15, a detecting circuit including the checking pin 14, the travel detector 15, and the third rivet 8 closes. The processor 100 registers the closed detecting circuit and controls the indicator to indicate that the fourth rivet 8 is attached to the workpiece 90; otherwise, if the fourth rivet 8 is not attached to the workpiece 90, the checking pin 14 can not be pressed, and the detecting circuit including the checking pin 14, the travel detector 15, and the third rivet 8 remains open. The processor 100 detects the open state and controls the indicator to indicate that the fourth rivet 8 is not attached to the workpiece 90. Similarly, the ways for checking whether the fourth rivet 7 and the third rivet 8 are attached to the workpiece 90, may be used to check the presence of other electrically conductive fasteners of the workpiece 90. Referring to FIG. 11 in conjunction with FIG. 8, FIG. 11 shows that accuracies of linearity and/or position of the first rivet 6 and the fourth rivet 7 are ineligible. A standard for judging whether the accuracy of linearity and/or position of the rivet 6, 7 is eligible is: if a deflection of linearity and/or position of the rivet 6, 7 is within an allowable tolerance, it is eligible. For the first rivet 6, suppose when the accuracy of linearity and/or position of the first rivet 6 is eligible with zero-deviation, an axis of the column-shaped space bounded by the checking sheath 4 of the upper checking member 80 is in line with an axis of the rivet 6. Suppose a diameter of a cross-section of the rivet 6 is equal to d6, a value of the allowable tolerance of the accuracy of linearity and/or position of the rivet 6 is equal to φ6, a diameter of a cross-section of the column-shaped space of the checking sheath 4 is equal to D6, and D6=d6+φ6. When the posts 5 of the upper checking member 80 press the workpiece 90, if the accuracy of linearity and/or position of the rivet 6 is eligible, the rivet 6 enters the checking sheath 4 without touching it, a detecting circuit including the checking sheath 4 and the first rivet 6 remains open, and no current goes through a circuit made up of the wire C, the checking sheath 4, the first rivet 6, the workpiece 90, the lower checking member 10, the wire E, and the electrical source. The processor 100 registers the detecting circuit is open and controls the indicator to indicate that the linearity and/or position of the first rivet 6 is eligible; otherwise, if the rivet 6 is ineligible, the rivet 6 touches the checking sheath 4, the detecting circuit including the checking sheath 4 and the first rivet 6 closes, and the processor 100 registers that the detecting circuit is closed and controls the indicator to indicate that the linearity and/or position of the first rivet 6 is ineligible. For the fourth rivet 7, suppose when the linearity and/or position of the fourth rivet 7 is eligible with zero-deviation, an axis of the column-shaped space bounded by the checking sheath 13 is in line with an axis of the rivet 7. Suppose a diameter of a cross-section of the rivet 7 is equal to d7, a value of the allowable tolerance of the accuracy of linearity and/or position of the rivet 7 is equal to φ7, a diameter of a cross-section of the column-shaped space of the checking sheath 13 is equal to D7, and D7=d7+φ7. When the posts 5 of the upper checking member 80 press out the workpiece 90, if the linearity and/or position of the rivet 7 is eligible, the rivet 7 enters the checking sheath 13 without touching it, a detection circuit including the checking sheath 13 and the fourth rivet 7 remains open, and no current goes through a circuit made up of the wire D, the checking pin 9, the fourth rivet 7, the checking sheath 13, the wire F, and the electrical source. The processor 100 registers that the detecting circuit is open and controls the indicator to indicate that the linearity and/or position of the first rivet 6 is eligible; otherwise, if the linearity and/or position of the rivet 6 is ineligible, the rivet 6 touches the checking sheath 4, and the detecting circuit including the checking sheath 13 and the fourth rivet 7 closes, and the processor 100 registers that the detecting circuit is closed and controls the indicator to indicate that the linearity and/or position of the first rivet 6 is ineligible. Referring to FIG. 12 in conjunction with FIGS. 8 and 9, FIG. 12 shows that height of the first rivet 6 is too high. A standard for judging whether the height of the rivet 6 is eligible is: if a deflection of height of the rivet 6 is limited in an allowable tolerance, it is eligible; otherwise, it is ineligible, and especially if a value of height of the rivet 6 is not less than an upper limitation of the allowable tolerance, the rivet 6 is too high. Suppose a value of the allowable tolerance of the height of the rivet 6 is equal to b. When the posts 5 of the upper checking member 80 press the workpiece 90, if the height of the rivet 6 is eligible, the checking pin 2 of the upper checking member 80 is pushed by the rivet 6 and moves upward, and a moving distance of the checking pin 2 is less than 2δ. Particularly, if there is no deflection of the height of the rivet 6, a distance between a touching piece 17 (shown in FIG. 9) of the checking pin 2 and the checking block 1 is equal to δ, and a distance between the touching piece 17 and the fixing sheath 18 is also equal to δ. At the same time, a first detecting circuit including the checking pin 2 and the first rivet 6 closes, and current of a first circuit flows from the electrical source through the wire A, the checking pin 2, the first rivet 6, the workpiece 90, the lower checking member 10, the wire E, and back to the electrical source. Because the checking pin 2 does not touch the checking block 1, a second detecting circuit including the checking pin 2 and the checking block 1 remains open, and no current goes through a second circuit made up of the wire B, the checking block 1, the checking pin 2, the first rivet 6, the workpiece 90, the lower checking member 10, the wire E, and the electrical source. The processor 100 registers that the first detecting circuit is closed and the second detecting circuit is open, and then controls the indicator to indicate that the height of the rivet 6 is eligible. Otherwise, if the height of the rivet 6 is too high, the checking pin 2 of the upper checking member 80 is pushed by the rivet 6 and moves upward, and a moving distance of the checking pin 2 is not less than 2δ. At the same time, the first detecting circuit including the checking pin 2 and the first rivet 6 closes, and current goes through the first circuit. Because the checking pin 2 moves upward so long a distance that the checking pin 2 touches the checking block 1, the second detecting circuit including the checking pin 2 and the checking block 1 closes, and current goes through the second circuit. The processor 100 registers that the first and second detecting circuits are closed and controls the indicator to indicate that the height of the rivet 6 is ineligible and too high. Similarly, the way for checking whether the height of the first rivet 6 is too high, may be used for checking whether the longer first rivet 6 is misplaced on a place of the shorter second rivet 16 should be instead. Referring to FIG. 13, in conjunction with FIGS. 8 and 9, FIG. 13 shows that height of the first rivet 6 is too low. A standard for judging whether the height of the rivet 6 is eligible is: if a deflection of height of the rivet 6 is limited in an allowable tolerance, it is eligible; otherwise, it is ineligible, and if a value of a height of the rivet 6 is less than a lower limitation of the allowable tolerance, the rivet 6 is too low. When the posts 5 of the upper checking member 80 press the workpiece 90, if the height of the rivet 6 is eligible, the checking pin 2 of the upper checking member 80 is propped up by the rivet 6 and moves upward, and a moving distance of the checking pin 2 is less than 2δ. At the same time, a detecting circuit including the checking pin 2 and the first rivet 6 closes, and current flows from the electrical source through the wire A, the checking pin 2, the first rivet 6, the workpiece 90, the lower checking member 10, the wire E, and back to the electrical source. The processor 100 receives a circuit closed signal and controls the indicator to indicate that the height of the rivet 6 is eligible. Otherwise, if the height of the rivet 6 is too low to touch the checking pin 2 of the upper checking member 80, the detecting circuit including the checking pin 2 and the first rivet 6 remains open, and the processor 100 registers that the circuit is open and controls the indicator to indicate that the height of the rivet 6 is ineligible and too low. Similarly, the way for checking whether the height of the first rivet 6 is too low, may be used for checking whether the shorter second rivet 16 is misplaced on a place of the longer first rivet 6 should be instead. Information of closing or opening of each circuits above is collected, judged and processed by the processor 100. According to the above description, a closed or open state of each circuit only relies on the corresponding detecting circuit including the fastener that needs to be checked and checking parts correlative with the fastener. Thus, in fact, what the processor 100 has done is collecting, judging and processing of information of closing or opening of the detecting circuits. The processor 100 sends processing result to the indicator made up of the display 42, the indicator light 44 and the bottom plate 62. If the indicator receives a result that all detected items of all the fasteners are eligible, the indicator light 44 shines and the display 42 indicates the workpiece 90 has passed. If the indicator receives a result that some detected items of the fasteners are ineligible, the bottom plate 62 alarms and the display 42 shows locations of the ineligible fasteners and the corresponding ineligible detected items. In other embodiments, an indicator may be made up of one or two of the display 42, the indicator light 44 and the bottom plate 62. Moreover, according to different needs of checking precision, the springs in the embodiment may be other elastic elements instead, such as acrylic resin, elasticity rubber, and hydraulic mechanism. It is believed that the present embodiments and their advantages is understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
|
H
|
H01
|
H01H
|
31
|
02
|
|||
11873334
|
US20080163385A1-20080703
|
METHOD AND APPARATUS FOR RAID ON MEMORY
|
ACCEPTED
|
20080619
|
20080703
|
[]
|
G06F1108
|
["G06F1108"]
|
7549020
|
20071016
|
20090616
|
711
|
114000
|
67748.0
|
FARROKH
|
HASHEM
|
[{"inventor_name_last": "Mahmoud", "inventor_name_first": "Fadi", "inventor_city": "Livermore", "inventor_state": "CA", "inventor_country": "US"}]
|
A method for protecting memory is provided. The method includes reading a block of data from a storage drive and writing the block of data to a first memory portion and a second memory portion. The method also includes managing the first memory portion and the second memory portion to protect the block of data. The block of data can be recovered from a non-failing portion in case either the first memory portion or the second memory portion fails.
|
1. A method for protecting memory, comprising: reading a block of data from a storage drive; writing the block of data to a first dual in-line module (DIMM) and a second DIMM plugged onto a single host adapter card coupled to the storage drive, wherein the first DIMM and the second DIMM are coupled to a single Redundant Array of Independent Disks (RAID) controller on the single host adapter card; and managing the first DIMM and the second DIMM to protect the block of data, wherein the block of data can be recovered from a non-failing DIMM in case either the first DIMM or the second DIMM fails. 2. The method of claim 1, wherein the first DIMM and the second DIMM plugged onto the single host adapter card are protected by Redundant Array of Independent Disks (RAID). 3. The method of claim 2, wherein the first DIMM and the second DIMM are protected by a RAID level 0. 4. The method of claim 2, wherein the first DIMM and the second DIMM are protected by a RAID level 1. 5. The method of claim 1, wherein the operation of managing the first DIMM and the second DIMM to protect the block of data is performed by a RAID Input/Output processor integrated on the single host adapter card. 6. The method of claim 1, wherein if either the first DIMM or the second DIMM is faulty, the faulty DIMM be replaced by another new DIMM by hot plugging. 7. The method of claim 1, wherein each of the first DIMM and the second DIMM is partitioned into multiple memory partitions. 8. A system for increasing a performance and fault tolerance of a computer system, the system comprising: a set of storage drives configured to store data; a first DIMM and a second DIMM protected by Redundant Array of Independent Disks (RAID), wherein the first DIMM and the second DIMM are plugged onto a host adapter card; and a single RAID controller configured to store data in the set of storage drives into the first DIMM and the second DIMM, wherein the first DIMM and the second DIMM are coupled to the single RAID controller, the single RAID controller is further configured to redundantly protect data stored into the first DIMM and the second DIMM, and the single RAID controller is integrated on the host adapter card. 9. The system of claim 8, wherein the single RAID controller implements a RAID level 0 to redundantly protect data stored into the first DIMM and the second DIMM. 10. The system of claim 8, wherein the single RAID controller implements a RAID level 1 to redundantly protect data stored into the first DIMM and the second DIMM. 11. The system of clam 8, wherein the single RAID controller includes a direct Memory access (DMA) engine configured to transfer data from the set of storage drives to the first DIMM and the second DIMM. 12. The system of claim 11, wherein the DMA engine has multi-channels to allow parallel transfer of data from the set of storage drives to the first DIMM and the second DIMM. 13. The system of claim 8, wherein the single RAID controller includes a firmware to virtually split each of the first DIMM and the second DIMM into multiple memory partitions. 14. The system of claim 8, wherein if either the first DIMM or the second DIMM is faulty, the faulty DIMM be replaced by another new DIMM by hot plugging.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to the field of computing technology, and more particularly, to methods and structures for optimizing the performance and fault tolerance of a computing system. 2. Description of the Related Art As is well known, computer systems typically include a processor, a main memory, and a secondary storage memory. Normally, the processor is a Central Processing Unit (CPU) or a microprocessor, the main memory is Random Access Memory (RAM), and the secondary storage is a hard disk drive. As the information such as data and instructions in RAM and the hard disk drives are executed by the processor, data protection has become one of the chief concerns in designing RAM and hard disk drives. Specifically, data protection is important as valuable data stored in hard disk drives, or temporarily held in RAM, can be lost due to abnormal occurrences such as human errors, equipment failures, and adverse environmental conditions. FIG. 1 illustrates a simplified schematic diagram of a host adapter card 102 of the prior art as it includes a dedicated memory 104 , a Redundant Array of Independent Disks (RAID) Input/Output Processor (RAID IOP) adapter chip 108 , and a Small Computer System Interface (SCSI) host adapter chip 110 . As shown, the host adapter card 102 is designed to be plugged into the primary PCI bus using a plug 112 . As also shown, the RAID IOP is coupled to the dedicated memory 104 through a bus 106 . Typically, the dedicated memory 104 can be either soldered to the motherboard or be a Dual In-Line Memory Module (DIMM) that is plugged onto the host adapter card 102 or a memory chip (not shown in the Figure). Irrespective of being soldered to the motherboard or being a DIMM, the larger the size of the dedicated memory 104 is, the better the performance of the computer system will be. For that reason, use of larger memory sizes has become a predominate trend. DIMMs have specifically played a significant role in promoting the use of expanded memory, because additional DIMMs can be added as a need for additional memory arises. Despite its advantages, using DIMMs has proven to be less than reliable. That is, despite using multiple DIMMs, the failure of one DIMM to function properly is disastrous and costly, as it results in system shut down. In one example, specifically, the failure of one DIMM used on the host adapter card results in the failure of the host adapter card 102 , which ultimately causes corruption of data. In such situation, the entire computing system must be shut down causing a significant loss. Additionally, shutting down the entire computer system further creates unknown effects on system components and data stored therein. Furthermore, eliminating the problem requires the replacement of the DIMM, subsequent to which, requires the reconfiguration of the entire system. In view of the foregoing, there is a need for a new methodology and apparatus for improving the performance and fault tolerance of computer systems through improving data integrity.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Broadly speaking, the present invention fills these needs by providing an apparatus and methods for improving the performance and increasing the fault tolerance of a computing system by using Redundant Array of Independent disks (RAID) on memory. In one implementation, the embodiments of present invention implement RAID on a dedicated memory of a host adapter card. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device, or a method. Several inventive embodiments of the present invention are described below. In one embodiment, a method for protecting memory is provided. The method includes reading a block of data from a storage drive. The method also includes writing the block of data to a first dual in-line module (DIMM) and a second DIMM plugged onto a single host adapter card coupled to the storage drive. The first DIMM and the second DIMM are coupled to a single Redundant Array of Independent Disks (RAID) controller on the single host adapter card. The method further includes managing the first DIMM and the second DIMM to protect the block of data. The block of data can be recovered from a non-failing DIMM in case either the first DIMM or the second DIMM fails. In another embodiment, a system for increasing a performance and fault tolerance of a computer system is provided. The system includes a set of storage drives configured to store data. The system further includes a first DIMM and a second DIMM protected by Redundant Array of Independent Disks (RAID), wherein the first DIMM and the second DIMM are plugged onto a host adapter card. In addition, the system includes a single RAID controller configured to store data in the set of storage drives into the first DIMM and the second DIMM. The first DIMM and the second DIMM are coupled to the single RAID controller. The single RAID controller is further configured to redundantly protect data stored into the first DIMM and the second DIMM. The single RAID controller is integrated on the host adapter card. The advantages of the present invention are numerous. Most notably, RAID on memory significantly increases system performance and the reliability of data in a computer system. For instance, the RAID level 0 on a host adapter card significantly improves the performance of the computer system. In one example, this occurs by using parallel reading and caching of data from a hard disk drive into a plurality of DIMMs or a plurality of virtual memory partitions. Another advantage of the present invention is that by using the RAID level 1 on memory, the highest reliability of data can be provided. Yet another advantage of performing RAID on memory is that by implementing multiple memory chips (e.g., DIMMs) to construct a dedicated array RAID array of memory on a host adapter card, the embodiments of the present invention facilitate performing of hot plugging on a faulty memory chip (e.g., DIMM). In this manner, the embodiments of the present invention substantially eliminate down time associated with shutting down the entire computing system to replace faulty memory. Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
|
CLAIM OF PRIORITY This application is a divisional application claiming priority under 35 U.S.C. § 120 of U.S. patent application Ser. No. 10/185,307, entitled “Method and Apparatus for RAID on Memory,” filed on Jun. 27, 2002, which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to the field of computing technology, and more particularly, to methods and structures for optimizing the performance and fault tolerance of a computing system. 2. Description of the Related Art As is well known, computer systems typically include a processor, a main memory, and a secondary storage memory. Normally, the processor is a Central Processing Unit (CPU) or a microprocessor, the main memory is Random Access Memory (RAM), and the secondary storage is a hard disk drive. As the information such as data and instructions in RAM and the hard disk drives are executed by the processor, data protection has become one of the chief concerns in designing RAM and hard disk drives. Specifically, data protection is important as valuable data stored in hard disk drives, or temporarily held in RAM, can be lost due to abnormal occurrences such as human errors, equipment failures, and adverse environmental conditions. FIG. 1 illustrates a simplified schematic diagram of a host adapter card 102 of the prior art as it includes a dedicated memory 104, a Redundant Array of Independent Disks (RAID) Input/Output Processor (RAID IOP) adapter chip 108, and a Small Computer System Interface (SCSI) host adapter chip 110. As shown, the host adapter card 102 is designed to be plugged into the primary PCI bus using a plug 112. As also shown, the RAID IOP is coupled to the dedicated memory 104 through a bus 106. Typically, the dedicated memory 104 can be either soldered to the motherboard or be a Dual In-Line Memory Module (DIMM) that is plugged onto the host adapter card 102 or a memory chip (not shown in the Figure). Irrespective of being soldered to the motherboard or being a DIMM, the larger the size of the dedicated memory 104 is, the better the performance of the computer system will be. For that reason, use of larger memory sizes has become a predominate trend. DIMMs have specifically played a significant role in promoting the use of expanded memory, because additional DIMMs can be added as a need for additional memory arises. Despite its advantages, using DIMMs has proven to be less than reliable. That is, despite using multiple DIMMs, the failure of one DIMM to function properly is disastrous and costly, as it results in system shut down. In one example, specifically, the failure of one DIMM used on the host adapter card results in the failure of the host adapter card 102, which ultimately causes corruption of data. In such situation, the entire computing system must be shut down causing a significant loss. Additionally, shutting down the entire computer system further creates unknown effects on system components and data stored therein. Furthermore, eliminating the problem requires the replacement of the DIMM, subsequent to which, requires the reconfiguration of the entire system. In view of the foregoing, there is a need for a new methodology and apparatus for improving the performance and fault tolerance of computer systems through improving data integrity. SUMMARY OF THE INVENTION Broadly speaking, the present invention fills these needs by providing an apparatus and methods for improving the performance and increasing the fault tolerance of a computing system by using Redundant Array of Independent disks (RAID) on memory. In one implementation, the embodiments of present invention implement RAID on a dedicated memory of a host adapter card. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device, or a method. Several inventive embodiments of the present invention are described below. In one embodiment, a method for protecting memory is provided. The method includes reading a block of data from a storage drive. The method also includes writing the block of data to a first dual in-line module (DIMM) and a second DIMM plugged onto a single host adapter card coupled to the storage drive. The first DIMM and the second DIMM are coupled to a single Redundant Array of Independent Disks (RAID) controller on the single host adapter card. The method further includes managing the first DIMM and the second DIMM to protect the block of data. The block of data can be recovered from a non-failing DIMM in case either the first DIMM or the second DIMM fails. In another embodiment, a system for increasing a performance and fault tolerance of a computer system is provided. The system includes a set of storage drives configured to store data. The system further includes a first DIMM and a second DIMM protected by Redundant Array of Independent Disks (RAID), wherein the first DIMM and the second DIMM are plugged onto a host adapter card. In addition, the system includes a single RAID controller configured to store data in the set of storage drives into the first DIMM and the second DIMM. The first DIMM and the second DIMM are coupled to the single RAID controller. The single RAID controller is further configured to redundantly protect data stored into the first DIMM and the second DIMM. The single RAID controller is integrated on the host adapter card. The advantages of the present invention are numerous. Most notably, RAID on memory significantly increases system performance and the reliability of data in a computer system. For instance, the RAID level 0 on a host adapter card significantly improves the performance of the computer system. In one example, this occurs by using parallel reading and caching of data from a hard disk drive into a plurality of DIMMs or a plurality of virtual memory partitions. Another advantage of the present invention is that by using the RAID level 1 on memory, the highest reliability of data can be provided. Yet another advantage of performing RAID on memory is that by implementing multiple memory chips (e.g., DIMMs) to construct a dedicated array RAID array of memory on a host adapter card, the embodiments of the present invention facilitate performing of hot plugging on a faulty memory chip (e.g., DIMM). In this manner, the embodiments of the present invention substantially eliminate down time associated with shutting down the entire computing system to replace faulty memory. Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, and like reference numerals designate like structural elements. FIG. 1 illustrates a simplified block diagram of a host adapter card in accordance with the prior art. FIG. 2 depicts a simplified schematic diagram of a computer system having a RAID array of virtual dedicated memory partitions, in accordance with one embodiment of the present invention. FIG. 3A is a simplified schematic diagram illustrating the achievement of higher performance through striping of data using RAID array of dedicated memory partitions, in accordance with yet another embodiment of the present invention. FIG. 3B is a simplified schematic diagram showing a plurality of DIMMs forming a RAID array of memory, in accordance with still another embodiment of the present invention. FIG. 3C is a simplified schematic diagram depicting striping of data from a RAID array of hard disks into a RAID array of virtual memory partitions, in accordance with still another embodiment of the present invention. FIG. 4A is a simplified schematic diagram illustrating a RAID level 1 on memory, in accordance with yet another embodiment of the present invention. FIG. 4B is a simplified schematic diagram illustrating caching of data from a RAID level 1 on hard disk drives to a RAID level 1 on memory constructing from a multiple DIMMs, in accordance with yet another embodiment of the present invention. FIG. 5 is a simplified schematic diagram of a computer system including a plurality of dedicated virtual memory partitions, in accordance with yet another embodiment of the present invention. FIG. 6 is a flowchart diagram of method operations performed in hot plugging a faulty DIMM, in accordance with yet another embodiment of the present invention. FIG. 7 is a flowchart diagram of method operations performed in hot plugging a single DIMM, in accordance with yet another embodiment of the present invention. FIG. 8 is a flowchart diagram of method operations performed in upgrading a DIMM through hot plugging, in accordance with yet another embodiment of the present invention. FIG. 9 is a flowchart diagram of method operations in performing a RAID level 1 on memory on a plurality of DIMMs, in accordance with yet another embodiment of the present invention. FIGS. 10A-10H illustrate a plurality of exemplary Graphic User Interfaces (GUI) in a RAID on Memory Utility, in accordance with yet another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An invention for computer implemented methods for increasing the performance and the fault tolerance of a computing system through ensuring integrity of data, is provided. Preferably, the embodiments of the present invention implement Redundant Array of Independent (Inexpensive) Disks (RAID) on Memory to improve the performance and the reliability of data in a dedicated memory of a host adapter card. In one example, RAID on memory includes a plurality of virtual memory partitions. In a different implementation, RAID on memory includes a plurality of memory chips. In one example, the memory chips implemented are DIMMs. By way of example, in a RAID level 0 on memory data, within a hard disk drive is stripped between a plurality of DIMMs, or a plurality of virtual memory partitions. In a different example, a RAID level 1 on memory, data within a hard disk is read and cached into a pair of DIMMs or two virtual memory partitions. Preferably, implementing multiple DIMMs enables the hot plugging of a faulty DIMM. Reference is now made to FIG. 2 illustrating a simplified schematic diagram of a computer system 200 having a RAID on memory including a plurality of dedicated virtual memory partitions 204a and 204b, in accordance with one embodiment of the present invention. The computer system 200 includes a host processor 214, a primary Peripheral Component Interconnect (PCI) bus 218, a host memory 216, a host adapter card 202, and a RAID array of hard disk drives 212. The host processor 214 and the host memory 216 are coupled to the primary PCI bus 218. The host processor 214 processes information such as data and instructions while the host memory 216 stores and provides information to the processor 214. The primary PCI bus provides a high speed data path between the CPU 214 and the connected peripheral devices so as to provide additional functionality. For instance, the RAID array of hard disk drives 212 is connected to the primary PCI 218 through a host adapter card 202. The host adapter card 202 is coupled to a secondary PCI bus 222 that is coupled to the PCI-system bus bridge 220. The host adapter card 202 is configured to interface and control access to the RAID array of hard disk drives 212. The host adapter card 202 includes a RAID Input/Output Processor (RAID IOP) 208, a dedicated memory 204, and a SCSI controller 210. The RAID IOP 208 includes a Direct Memory Access (DMA) engine 209 configured to transfer data from the RAID array of hard disk drives 212 to one or more of virtual memory partitions 204a and 204b of the RAID array of virtual memory partitions 204. In one example, the DMA engine has multi-channels thus allowing parallel transfer of data from any of the hard disk drives 212a and 212b to any of virtual memory partitions 204a and 204b of the RAID array of virtual memory partitions 204. In one embodiment, the RAID IOP further includes a memory controller 211 configured to interface and control access to the virtual memory partitions 204a and 204b of the RAID array of virtual memory partitions 204. Achieving higher performance through striping of data using RAID array of dedicated memory partitions 204 can further be understood with respect to the simplified schematic diagram shown in FIG. 3A, in accordance with one embodiment of the present invention. As shown, data stored in the RAID array of hard disk drives 212 is cached into the RAID array of dedicated memory partitions 204. The RAID array of hard disk drives 212 includes a plurality of hard disk drives 212a through 212n. One container 212′ shows two hard drives 212a and 212b respectively transferring 64 Mbytes of data in portions 214a and 214b using a stripping technique. Each portion 214a and 214b writes 32 Mbytes of data in 204a-1 and 204b-1, and 204a-2 and 204b2 of virtual memory partitions 204a and 204b, correspondingly. In one exemplary embodiment, a plurality of parameters of a desired memory RAID level is provided to the DMA engine 209 of the RAID IOP 208. For instance, in the embodiment of FIG. 3A, a desired RAID level 0, which is memory striping, is provided to the RAID IOP 208. That is, data stored in the RAID array of hard disk drives 212 are interleaved across multiple virtual memory partitions 204a and 204b, providing increased performance. As shown, a portion of the hard disk drive 212a of the RAID array of hard disk drives 212 operates on data sectors totaling 64 MB, which under RAID on memory level 0 is configured to be stripped between the virtual memory partition 204a and 204b, equally. That is, the data contents of the portion 214a of the hard disk drive 212a is read and subsequently interleaved equally between the virtual memory partitions 204a and 204b. By way of example, using 213a, a first 32 Mbytes of data in the hard disk 212a is read and then cached in 204a-1 of the virtual memory partition 204a. Then, using the 213a′, a second 32 Mbytes of data in the hard disk drive 212a is read and cached in 204b-1 of the virtual memory partition 204b. Similarly, a first portion of data stored within hard disk drive 212b is read and cached in 204a-2 of virtual memory partition 204a using 213b. In a like manner, a second portion of data stored within the hard disk drive 212b is read and cached into a 204b-2 of the virtual memory partition 204b. In one example, the DMA engine is designed such that it is multi-channeled giving the DMA engine the capability to transfer the first and second portions of data within the hard disk drive 212a in parallel. In this manner, advantageously, the period of time required to read the entire 64 Mbytes of data stored within the hard disk drive 212a is reduced substantially by half. In a like manner, reading of the first and second portions of data stored within the hard disk drive 212b and caching same into the first and second virtual memory partitions is reduced substantially by half. Additionally, it must be noted that in a different embodiment, the time required to read data stored in each of the hard disk drives 212a and 212b may be reduced by caching the stored data within each of the hard disk drives 212a and 212b into three or four (i.e., more than two) virtual memory partitions. In this manner, the time required to read the 64 Mbytes of data stored in each portion 214a and 214b of the corresponding hard disk drives 212a and 212b can be reduced by one-third and one-fourth, respectively. In a different implementation, as shown in FIG. 3B, a plurality of DIMMs 204 and 204′ can be used to cache data read from each of the hard disk drives 212a and 212b, in accordance with one embodiment of the present invention. In this example, the first portion of the 64 Mbytes data stored in the hard disk drive 212a is read and then cached into a 204-1 of a DIMM 204 using 213a. In a same manner, the second portion of data stored in hard disk drive 212a is read and cached into a 204′-1 of a DIMM 204′ using 213a′. As shown, as a result of being multi-channeled, the DMA engine 209 is capable of reading the first portion and the second portion of data in the hard disk drive 212a in parallel, reducing the time required for caching the entire data by half. Similarly, the first portion of data stored in the hard disk drive 212b is read and then cached into 204-2 of DIMM 204 using 213a′. Then, the second portion of data stored in the second hard disk drive 212b is read and cached into 204′-2 of DIMM 204′ using 213b′. Thus, again, the multi-channel DMA engine 209 enables the parallel reading of the first and second portions of the hard disk drive 212b as well as parallel caching of the first and second portions of the data in 204-2 of DIMM 204 and 204′-2 of DIMM 204′. Data read from each of the hard disk drives 212a and 212b is beneficially interleaved between two DIMMs, in parallel, thus reducing the time required to read and write data substantially by half. It must be noted that although the embodiments of the present invention are shown to include DIMMs, one having ordinary skill in the art should appreciate that any suitable memory chip can be implemented to store data (e.g., memory sticks, Single In-line Memory Module (SIMMs), etc.) Reference is made to FIG. 3C depicting the striping of data from the RAID array of hard disk drives 212 into a RAID array of virtual memory partitions 204, in accordance with one embodiment of the present invention. As shown, the memory 204 has been virtually divided into four partitions of 204a through 204d. In one example, a first portion of data stored within the hard disk drive 212a is cached and stripped into 204a-1, the second portion of data stored within the hard disk drive 212a is cached and interleaved into 204b-1, a third portion of data stored within the hard disk drive 212a is cached and interleaved into 204c-1, and a fourth portion of data stored within the hard disk drive 212a is cached and interleaved into 204d-1, respectively. Similarly, the first portion of data stored within the hard disk drive 212b is cached and interleaved into the 204a-2 of the first virtual memory partition 204a, the second portion of data stored within the hard disk drive 212b is cached and interleaved into the 204b-2 of the second virtual memory partition 204b, the third portion of data stored within the hard disk 212b is cached and interleaved into 204c-2 of the third virtual memory partition 204c, and the fourth portion of data stored within the hard disk 212b is cached and interleaved into 204d-2 of the fourth virtual memory partition 204d, correspondingly. In one exemplary embodiment, each of the first portions of the hard disks 212a and 212b are cached into 204a-1 and 204a-2 using 213a and 213b. In a like manner, each of the second portions of the hard disks 212a and 212b are cached into 204b-1 and 204b-2 using 213a′ and 213b′; each of the third portions of the hard disks 212a and 212b are cached into 204c-1 and 204c-2 using 213a″ and 213b″; and each of the fourth portions of the hard disks 212a and 212b are cached into 204d-1 and 204d-2 using 213a′″ and 213b′″. This is specifically made possible by the multi-channel DMA engine capable of reading and caching data from multiple hard disk drives into multiple virtual memory partitions of the memory. Turning to FIG. 4A, implementing a RAID level 1 on memory can further be understood, in accordance with one embodiment of the present invention. The RAID level 1 on memory is mirroring which is one-hundred percent duplication of data within the disks. In the embodiment of FIG. 4A, data within the hard disk drive 212a and 212b are duplicates, providing higher system reliability. In accordance to one example, data stored within the hard disk drive 212a (e.g., a data portion 214a of 64 MB) is read and cached into the first virtual memory partition 204a. Similarly, data stored within the hard disk drive 212b (e.g., a data portion 214b of 64 MB) is read and cached into the virtual memory partition 204b, in parallel. As discussed in more detail above, parallel caching of data stored within the hard disk drives 212a and 212b has been made possible using the multi-channel DMA engine 209 and the virtual splitting of the memory into two virtual partitions, each having a size of 64 MB. Each of the first and second memory partitions 204a and 204b having the size of 64 Mbytes is capable of caching in 64 Mbytes of data, which in this embodiment, are identical. Of course, memory can have much larger sizes, but for purposes of example, 64 Mbytes is used. In this manner, data duplicated within the hard disk drives 212a and 212b are also duplicated in virtual memory partitions 204a and 204b, increasing the reliability of the system. As a consequence, a corruption of data cached into the second virtual memory partition 204b will have no significant negative effect, as an identical copy of the data is cached into the first virtual memory partition 204a. Thus, the RAID level 1 on memory of the present invention beneficially increases the fault tolerance of the system. In a different example, as shown in FIG. 4B, multiple DIMMs can be implemented to cache duplicated data stored within the hard disk drives 212a and 212b using the RAID level 1 on memory of the present invention, in accordance with one embodiment of the present invention. As illustrated, data portion 214a stored within the hard disk drive 212a having a size of 64 Mbytes or larger is read and cached into a first DIMM 204 while data portion 214b stored within the hard disk drive 212b is read and cached into the second DIMM 204′. Each of the first DIMM and the second DIMM 204 and 204′ has a size of 64 Mbytes, as shown in 204-1 and 204′-1 and each has a respective address of X and Y. That is, when different DIMMs are implemented to cache duplicated data, the caching of data is facilitated by using each of the addresses of the first and second DIMMs 204 and 204′. Again, in this embodiment, duplicated data stored within the hard disk drives 212a and 212b are cached into two different DIMMs 204 and 204′, despite the data within the two hard disk drives 212a and 212b being duplicate. In this manner, corruption of data within the first and second DIMMs 204 or 204′, respectively, has a minimal negative effect on the system. A simplified schematic diagram of a computer system 500 having a RAID array on memory of a plurality of virtual memory partitions 204a and 204b is illustrated in FIG. 5, in accordance with one embodiment of the present invention. The computer system 500 includes a host processor (CPU) 214, a primary Peripheral Component Interconnect (PCI) bus 218, a host memory 216, a host adapter card 202, and a RAID array of hard disk drives 212. The primary PCI bus provides a high speed data path between the CPU 214 and the connected peripheral devices. The RAID array of hard disk drives 212 is connected to the primary PCI 218 through a host adapter card 202. The secondary PCI bus 222 is coupled to the PCI-system bus bridge 220. The host adapter card 202 interfaces and controls access to the RAID array of hard disk drives 212. The host adapter card 202 includes a RAID Input/Output Processor (RAID IOP) 208, a RAID array of dedicated memory 204, and a SCSI controller 210. The RAID IOP 208 includes a Direct Memory Access (DMA) engine 209, firmware 217, and a controller 211. The DMA engine is configured to transfer data from the RAID array of hard disk drives 212 to one or more of virtual memory partitions 204a and 204b of the dedicated RAID array of memory 204. In one example, the DMA engine 209 has multi-channels, thus allowing parallel transfer of data from any of the hard disk drives 212a and 212b to any of virtual memory partitions 204a and 204b of the dedicated RAID array of memory 204. The memory controller 211 interfaces and controls access to the virtual memory partitions 204a and 204b of the dedicated RAID array of memory 204 implementing 206a and 206b, respectively. The firmware 217 is a software interface configured to run on the RAID IOP. In one example, the RAID parameters (e.g., RAID level, necessary number of virtual memory partitions, number of containers, etc.) are defined by the firmware 217. The firmware 217 then implements the parameters to virtually split the dedicated memory 204. Thus, the firmware 217 is aware of the number of virtual memory partitions and their associated addresses. FIG. 6 illustrates a flow chart 600 of method operations performed in hot plugging a faulty DIMM, in accordance with one embodiment of the present invention. The method begins in operation 602 in which the host adapter card is configured so as to include more than one DIMM. Then, in operation 604, an error is detected in one of the DIMMs. For instance, depending on the situation, the error may be having a faulty DIMM or having corrupted data on one of the DIMMs. Proceeding to operation 604, it is determined that the error is due to having a faulty DIMM. Upon making such detection, in operation 608, a user's input to replace the faulty DIMM is received. In one example, the user is configured to interact using a RAID interface software such as Storage Manager Professional (SMPro) or Storage Manager on ROM (SMOR), both of which are RAID software interfaces developed by Adaptec of Milpitas in California. Continuing to operation 610, the integrity of data in the faulty DIMM is ensured by reading out data content of the faulty DIMM. Next, in operation 612, the faulty DIMM is hot plugged. As used herein, “hot plugging a DIMM” is defined as shutting down the power to the existing DIMM in the computer system thus allowing the removal of same while the computer system power and the host adapter card power are still on and operating. Thus, in operation 612, the power to the faulty DIMM is shut down, which in one embodiment, is performed by the firmware. Next, in operation 614, the faulty DIMM is removed and replaced. Upon replacing the faulty DIMM, in operation 616, connection is established to the replaced DIMM. In one instance, the firmware restores power to the replaced DIMM. Then, in operation 618, the data content of the faulty DIMM is restored into the replacement DIMM. In this manner, the integrity of data cached into a plurality of DIMMs forming a RAID array of memory is beneficially ensured without the necessity of shutting down the power to the entire system. Turning to flowchart diagram 700 of method operations shown in FIG. 7, hot plugging a DIMM can further be understood, in accordance with one embodiment of the present invention. The method begins in operation 702, in which the host adapter card is configured to include a single DIMM followed by operation 704 wherein an error is detected in the DIMM. In one instance, it may be detected that the DIM is faulty while in a different embodiment, it may be determined that data to be cached into the DIMM is corrupted. Next, in operation 706, the user is provided with different mechanisms to recover data in the DIMM, depending on the error occurring during reading of data from the host memory or from the operating system. For instance, the error may have occurred during reading of data from the operating system in the computer system that includes RAID on hard disk drives. In such situation, if RAID level 0 is implemented, the portion of valid data that is still available is recovered and the user is informed of the loss of a portion of the data. If RAID level 1 is implemented, the copy of the data is implemented to restore the data in the faulty DIMM. If RAID level 5 is used, the lost data is regenerated. In a different scenario, where error has occurred during reading of data from host memory, a copy of the data may be recovered using the data in the host memory. Continuing to operation 708, the user input to replace the DIMM is received. In one example, the interface between the user and the RAID on memory may be SMPro or SMOR. Next, in operation 710, the DIMM is hot plugged. That is, the power to the DIMM is shut down while the system power is still on. Then, the DIMM is removed and replaced in operation 712, which is followed by operation 714 wherein the connection to the replaced DIMM is established. In operation 716, the data recovered in operation 706 is restored into the replaced DIMM, if such request has been made by the user. Thus, data in one DIMM can be recovered implementing the hot plug feature of the present invention, beneficially eliminating the necessity to shut down the system power. In this manner, the loss of memory and the valuable time associated with shutting down the system as well as reconfiguring the system is reduced. The method operations in upgrading a DIMM by hot plugging the DIMM is illustrated in the method operations of flowchart 800 depicted in FIG. 8, in accordance with one embodiment of the present invention. The method begins in operation 802 in which a user's decision to upgrade a DIMM is received. Next, in operation 804, the user's decision is communicated to the firmware defined on RAID IOP. In one example, the SMPro or SMOR software is used to provide interaction between the firmware and the user. Continuing to operation 806, the selected DIMM is hot plugged. That is, the power connected to the selected DIMM is shut down. This is advantageous, as in contrast to the prior art, the embodiments of the present invention do not necessarily have to use the operating system, the drivers, and application layers to interact with the firmware so as to hot plug the DIMM That is, in the embodiments of the present invention, depending on the operating system environment, the user can implement the operating system and one of the RAID user interfaces to communicate with the firmware almost directly. Thus, the embodiments of the present invention advantageously enable a user to hot plug the DIMM rather than shutting down the entire system or the host adapter card. In operation 806, the old DIMM is replaced with an upgraded DIMM. For instance, a DIMM having a 64 Mbytes memory size is upgraded to a DIMM having a 128 Mbytes memory size. Then, in operation 810, connection is established to the upgraded DIMM. That is, the firmware restores power to the replaced DIMM. Thereafter, in operation 812, the user is informed of the status of the upgraded DIMM. In one embodiment, SMPro or SMOR software interface is implemented to interact with the user. FIG. 9 depicts the flowchart 900 of method operations performed in RAID level 1 on a plurality of DIMMs forming a RAID array of memory, in accordance with one embodiment of the present invention. The method begins in operation 902 in which a hard disk having data stored therein is provided. Next, in operation 904, a portion of data stored in the hard disk is read and is then written on a first address on a DIMM in operation 906. Proceeding to operation 908, the portion of data read in operation 904 is written to a second address located on a different DIMM. In this manner, data stored in a portion of a single hard disk drive is read and written into two DIMMs, increasing the reliability of data in a dedicated memory. In one example, using different addresses to write data is an indication of having physically different DIMMs. FIGS. 10A-10G illustrate a plurality of exemplary Graphic User Interfaces (GUI) in a RAID On Memory Utility, in accordance with one embodiment of the present invention. In one example, upon booting the system, the RAID on Memory utility is initiated checking on substantially all DIMMs within the dedicated memory. As shown, the utility verifies the number of DIMMs in the system and provides the user with such information. Upon detecting the number of active DIMMs, using dialog boxes 1004 and 1006, the user is informed of the detection of the two DIMMs. Thereafter, continuing with the initialization process, in boxes 1008 and 1010, the user is informed of the detection of an error in DIMM 1. Using boxes 1012 and 1014, the user is informed as to the need to replace DIMM 1. Using boxes 1016-1026, the user is given an option to replace DIMM 1. As shown, in boxes 1020 and 1022, the user has selected to replace DIMM 1. In boxes 1028 and 1030, the user is given the option to initiate the hot plugging of DIMM 1. As shown, the user is given an option to either press the start button 1034 or an exit button 1036 to leave the RAID on Memory utility. The user is further given an opportunity to seek help using the help button 1032. Continuing to FIG. 10B, the progress of the RAID on Memory utility is shown in further detail. Implementing the box 1038, the user is informed of the initiation of hot plugging of DIMM 1. Then, in box 1040 depicted in FIG. 10C, the user is informed that data content of DIMM 1 is read followed by a box 1042, in which the power is shut down to DIMM 1. Next, in box 1044, the user is instructed to replace DIMM 1 followed by a request in box 1046 requesting pressing of a continue button 1048. The power to DIMM 1 is then restored as shown in box 1050 of FIG. 10F. Following the restoring of power to DIMM 1, the data content of DIMM 1 is restored as shown in box 1052 of FIG. 10G. As shown in box 1054, the user is then informed of the successful restoring of data to DIMM 1 confirmed by a done button 1056. It must be appreciated by one having ordinary skill in the art that the SCSI controller of the present invention may be integrated into a motherboard of computer systems as opposed to being on an adapter card. Additionally, the present invention may be implemented using an appropriate type of software driven computer-implemented operation. As such, various computer-implemented operations involving data stored in computer systems to drive computer peripheral devices (i.e., in the form of software drivers) may be employed. These operations are those requiring physical manipulation of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared and otherwise manipulated. Further, the manipulations performed are often referred to in terms such as ascertaining, identifying, scanning, or comparing. Any of the operations described herein that form part of the invention are useful machine operations. Any appropriate device or apparatus may be utilized to perform these operations. The apparatus may be specially constructed for the required purposes, or it may be a general purpose computer selectively activated or configured by a computer program stored in the computer. In particular, various general purpose machines may be used with computer programs written in accordance with the teachings herein, where it may be more convenient to construct a more specialized apparatus to perform the required operations. Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.
|
G
|
G06
|
G06F
|
11
|
08
|
|||
11776269
|
US20080012247A1-20080117
|
Chuck and Method for Manufacturing a Chuck
|
ACCEPTED
|
20080103
|
20080117
|
[]
|
B23B522
|
["B23B522"]
|
7963527
|
20070711
|
20110621
|
279
|
002100
|
68982.0
|
JANESKI
|
PAUL
|
[{"inventor_name_last": "Weller", "inventor_name_first": "Hans-Michael", "inventor_city": "Affalterbach", "inventor_state": "", "inventor_country": "DE"}]
|
A chuck (10) has a chuck body (12), which is provided with three guide devices (24), on each of which is received a radially movable clamping holder (34) for fixing a workpiece to chuck body (12), the guide device (24) being constructed separately from the chuck body (12). Guide device (24) is integrally joined by a polymer concrete filling (46) to the chuck body (12) for a force transfer between guide device (24) and chuck body (12). There is no need for a particularly precise manufacture of the outer contour of guide device (24) and the recess (20) in chuck body (12), because the polymer concrete (46) is able to compensate tolerances.
|
1. Chuck with a chuck body, said chuck body being provided with at least one guide device, wherein on said guide device is received at least one movable clamping holder for fixing a workpiece to said chuck body, wherein said guide device is fabricated as a separate part from said chuck body. 2. Chuck according to claim 1, wherein said clamping holder is radially movable. 3. Chuck according to claim 1, wherein said guide device is fixed integrally to said chuck body. 4. Chuck according to claim 1, wherein said chuck body has a recess and a gap is provided on said chuck, said gap being at least substantially bordered by said guide device and said recess, wherein said gap is at least partly filled with a hardenable filling material. 5. Chuck according to claim 4, wherein said filling material is one of polymer concrete or cast mineral. 6. Chuck according to claim 4, wherein said guide device and said recess in said chuck body are so matched to one another so that on fixing a workpiece, said filling material is at least preponderantly subject to a compressive force. 7. Chuck according to claim 6, wherein said recess and said guide device have matched projections and recesses being constructed for a transfer of said compressive force between said chuck body and said guide device via said filling material. 8. Chuck according to claim 4, wherein said recess (20) has a profiling, said profiling having a longitudinally cross-section bring at least substantially constant. 9. Chuck according to claim 8, wherein said profiling is undercut and a profiling axis is oriented at least substantially in radial direction of said chuck. 10. Chuck according to claim 1, wherein said guide device and said clamping holder bound at least one guide area of said chuck. 11. Chuck according to claim 10, wherein said guide area extends parallel to a radial direction and is constructed for receiving at least one guide means. 12. Chuck according to claim 1, wherein said guide device is formed from at least two substantially identically shaped guide parts, said guide parts being coupled together by joining means. 13. Chuck according to claim 12, wherein said guide parts are constructed or arranged in homologous manner to a plane of symmetry and homologously to a radial plane of chuck body. 14. Chuck according to claim 1, wherein said clamping holder for fixing said workpiece is coupled to an operating device, said operating device being constructed for introducing radially inwardly directed operating forces onto said clamping holder. 15. Chuck according to claim 14, wherein said operating device is constructed for controlling said clamping holder by means of an operating member adjustable parallel to a machine spindle axis. 16. Chuck according to claim 1, wherein said clamping holder is mounted by means of a rolling guide in said guide device. 17. Chuck according to claim 16, wherein in said rolling guide cylindrical rollers are provided as rolling members. 18. Chuck according to claim 17, wherein said rolling members form a rolling guide in such a way that said clamping holder is exclusively movable along a longitudinal direction of said rolling guide. 19. Chuck according to claim 17, wherein said guide faces are provided on said guide device for said rolling members and said guide faces are inclined to a centre axis of said chuck and are provided on said guide parts. 20. Method for the manufacture of a chuck according to claim 1, said method having the steps of: receiving said guide parts on an orienting means, fitting and fixing said orienting means to said chuck body using at least one orientation geometry corresponding to said orienting means and provided on said chuck body, where on fitting said orienting means to said chuck body said guide parts are inserted in recesses of said chuck body, integral joining of the guide parts to said chuck body. 21. Method according to claim 20, wherein for said integral joining of said guide part to said chuck body, at least one said gap bordered by said guide part and said chuck body is filled with a hardenable material. 22. Method according to claim 21, wherein said hardenable material is one of polymer concrete or cast mineral. 23. Method according to claim 20, wherein said guide parts are coupled together by joining means, at least during an integral joining. _
|
<SOH> FIELD OF APPLICATION AND PRIOR ART <EOH>The invention relates to a chuck with a chuck body provided with at least one guide device on which is received at least one movable clamping holder for fixing a workpiece to the chuck body, as well as a method for manufacturing a chuck. The clamping holder is particularly radially movable. Chucks for use on a rotary machine spindle are known, particularly on a machine spindle of a lathe, or for fixing to a machine table, particularly to a machine table of a milling machine or a machining centre. Using the chuck a workpiece to be machined can be precisely fixed with a high repetition accuracy to the machine spindle or to the machine table. Following the fixing of the workpiece a machining process can be carried out on the workpiece. Machining forces occurring on the workpiece can be transferred via the chuck to the machine spindle or machine table. To this end the known chuck has a chuck body, which is typically provided with an interface for force-transmitting coupling to the machine spindle or machine table. In order to fix a workpiece to the chuck, there must be at least one clamping or chucking holder movably received on the chuck body. The clamping holder can be constructed as a clamping device for direct force transfer and with contact to the workpiece to be machined or as a clamping device support for receiving such a clamping device. At least one guide device is provided for the movable reception of the clamping holder on the chuck body. In the case of the known chuck the guide device is recessed into the chuck body and permits a relative movement between clamping holder and chuck body. The relative movement has an at least proportionately radially oriented component of motion and preferably the relative movement takes place exclusively radially. The guide device also permits a transfer of clamping forces applied for fixing the workpiece to the chuck. In the known chuck the clamping holder is fitted in a radial direction in linearly movable manner with respect to the cylindrically designed chuck body. In order to achieve an exact, repetition-accurate fixing of the workpiece to the chuck body, a precise clamping holder guidance must be ensured. Only then is it possible during each clamping process for the workpiece to be located in the same position. When using the clamping device on a machine spindle of a lathe, it is also necessary to ensure a precise alignment of the workpiece relative to a rotation axis of the machine spindle. Otherwise an undesired concentricity error occurs during a machining process on the lathe. It is consequently necessary to ensure that the clamping holder or holders are oriented and positionable in an exact manner to a reference geometry on the chuck serving as the interface. The reference geometry is provided for a precise orientation with respect to the machine spindle. In the case of chucks for lathes a considerable proportion of the manufacturing costs for the chuck are a result of the need for a precise manufacture of the clamping holder and the need for a precise manufacture of the guide devices relative to the reference geometry.
|
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>Embodiments of the invention are diagrammatically represented in the drawings and are explained in greater detail hereinafter. In the drawings show: FIG. 1 A perspective view of a chuck with three guide devices having the same angular spacing. FIG. 2 A part sectional detail enlargement of the chuck of FIG. 1 . FIG. 3 A plan view of a chuck similar to FIGS. 1 and 2 . FIG. 4 A lateral sectional representation along the section path I-I in FIG. 3 . FIG. 5 A variant of a chuck in a view corresponding to FIG. 4 with a rolling guide. detailed-description description="Detailed Description" end="lead"?
|
The following disclosure is based on German Patent Application No. 10 2006 033 396.9 filed on Jul. 13, 2006 which is herewith incorporated into this application by explicit reference. FIELD OF APPLICATION AND PRIOR ART The invention relates to a chuck with a chuck body provided with at least one guide device on which is received at least one movable clamping holder for fixing a workpiece to the chuck body, as well as a method for manufacturing a chuck. The clamping holder is particularly radially movable. Chucks for use on a rotary machine spindle are known, particularly on a machine spindle of a lathe, or for fixing to a machine table, particularly to a machine table of a milling machine or a machining centre. Using the chuck a workpiece to be machined can be precisely fixed with a high repetition accuracy to the machine spindle or to the machine table. Following the fixing of the workpiece a machining process can be carried out on the workpiece. Machining forces occurring on the workpiece can be transferred via the chuck to the machine spindle or machine table. To this end the known chuck has a chuck body, which is typically provided with an interface for force-transmitting coupling to the machine spindle or machine table. In order to fix a workpiece to the chuck, there must be at least one clamping or chucking holder movably received on the chuck body. The clamping holder can be constructed as a clamping device for direct force transfer and with contact to the workpiece to be machined or as a clamping device support for receiving such a clamping device. At least one guide device is provided for the movable reception of the clamping holder on the chuck body. In the case of the known chuck the guide device is recessed into the chuck body and permits a relative movement between clamping holder and chuck body. The relative movement has an at least proportionately radially oriented component of motion and preferably the relative movement takes place exclusively radially. The guide device also permits a transfer of clamping forces applied for fixing the workpiece to the chuck. In the known chuck the clamping holder is fitted in a radial direction in linearly movable manner with respect to the cylindrically designed chuck body. In order to achieve an exact, repetition-accurate fixing of the workpiece to the chuck body, a precise clamping holder guidance must be ensured. Only then is it possible during each clamping process for the workpiece to be located in the same position. When using the clamping device on a machine spindle of a lathe, it is also necessary to ensure a precise alignment of the workpiece relative to a rotation axis of the machine spindle. Otherwise an undesired concentricity error occurs during a machining process on the lathe. It is consequently necessary to ensure that the clamping holder or holders are oriented and positionable in an exact manner to a reference geometry on the chuck serving as the interface. The reference geometry is provided for a precise orientation with respect to the machine spindle. In the case of chucks for lathes a considerable proportion of the manufacturing costs for the chuck are a result of the need for a precise manufacture of the clamping holder and the need for a precise manufacture of the guide devices relative to the reference geometry. PROBLEM AND SOLUTION The problem of the invention is to improve a chuck and a method for the manufacture of a chuck in such a way that there is a simplified manufacture with reduced manufacturing costs. This problem is solved by a chuck having the features of claim 1 and by a chuck manufacturing method having the features of claim 20. Advantageous and preferred developments of the invention are given in the remaining claims and are explained in greater detail hereinafter. Features describing both the chuck and the manufacturing method are in part only described once hereinafter. However, independently thereof, they apply both to the chuck and the manufacturing method. By express reference the wording of the claims is made into part of the content of the description. According to a first fundamental aspect of the invention a chuck of the aforementioned type is provided, in which the guide device is fabricated separately and as a part originally separate from the chuck body and consequently constitutes a discrete chuck component. Thus, different materials and/or manufacturing methods specifically matched to the requirements of the given components can be chosen for the chuck and for the guide device. For the guide device it is preferable to choose a high strength material, which permits a reliable transfer of high forces between workpiece and chuck body. For the chuck body use is preferably made of a lighter and possibly less expensive material than for the guide device. With a lightweight chuck body the forces which occur when using the chuck on a moving machine spindle as a result of unbalances and acceleration/deceleration processes, can be kept low. Additionally the guide device can be manufactured using manufacturing and/or surface working steps which, for technical reasons or cost reasons, cannot be used for the chuck body. The chuck body is preferably a steel or aluminium member made by turning and/or milling processes. The guide device is preferably manufactured by milling, forging, extrusion, metal casting, precision casting, grinding or a combination of such working processes. Besides steel, the guide device material can be titanium or some other high strength alloys, which could not be used for the manufacture of the entire chuck body as a result of cost. The guide device can also be given a surface coating in order to produce a particularly high load capacity surface. The coating process can for example be nitriding or chromizing, particularly coating with titanium nitride. The cross-section of the guide device and in particular the guide in the clamping holders is arbitrary and undercut cross-sections with a slope or step shape such as for example a T-shape are particularly advantageous. According to a development of the invention, the guide device is integrally fixed to the chuck body. An integral fixing can in particular be obtained by welding, soldering, bonding, casting or by a combination of such joining processes. There can be a direct contact between the chuck body and the guide device, as is implemented when welding by fusing together the materials of the chuck body and guide device. In a welding process using filling material or during soldering, bonding or casting a filling material is introduced between the chuck body and the guide device and interconnects the two parts. The use of a filling material makes it possible to compensate shape differences between the guide device and chuck body. Such shape differences are present as shape and position tolerances for the manufacture of the guide device and chuck body and significantly influence the manufacturing costs. Moreover, as a result of the filling material, different materials, which can for example not be welded together, can be firmly interconnected through the other, aforementioned joining methods. Apart from joining the parts, the filling material can also serve as a damping layer and/or as an elastic layer, in order to damp force peaks and reduce the transfer of vibrations between the connected components. According to a further development of the invention a gap, which is at least substantially bounded by the guide device and a recess in the chuck body, is at least partly filled with a hardenable filling material, particularly with polymer concrete. The gap is preferably dimensioned in such a way that the geometries of the chuck body and guide device bounding the gap can have rough tolerances, so that these geometries can be inexpensively manufactured. Even in the case of an unfavourable tolerance combination for the geometries, there is still an adequate volume available for the hardenable filling material. The filling material can in particular be constituted by temporarily flowable mixtures, which for example have a binder and a hardener and which harden through the activation of the binder by the hardener after a predeterminable time. In a preferred embodiment of the invention polymer concrete is used as the filling material. Polymer concrete or cast mineral is a material made from mineral fillers such as granite, basalt, chalk, quartz gravel, quartz sand or stone dust in in each case different granularities and with a small proportion of reaction resins such as epoxy resin or miscellaneous binders. The material is mixed and poured cold into a mould in the form of a homogeneous mass. Compared with other materials, such as for example plastics, polymer concrete is characterized in that it has a particularly low and therefore advantageous shrinkage behaviour during hardening. The density of polymer concrete is much lower than that of conventional materials, particularly metals, used in the manufacture of chucks. Thus, it is a nonmetallic material, whose characteristics with regards to density, elasticity and damping can be adjusted within a wide range. Like other filler materials usable for the chuck, the polymer concrete can be filled with artificial and/or natural fibres in order to bring about a better load bearing capacity, particularly with respect to tensile forces. In a further development of the invention, the guide device and the recess in the chuck body are matched to one another in such a way that during the fixing of a workpiece the filling material is at least preponderantly subject to compressive forces or stresses. The filling material typically has a much higher compressive load bearing capacity than tensile load bearing capacity. An appropriate matching of chuck body and guide device consequently permits the complete utilization of the positive properties of the filling material. In a further development of the invention, the recess and the guide device have matched projections, which are constructed for a transfer of compressive forces between the chuck body and guide device via the filling material. As a result of the projections on the guide device and on the chuck body it is preferably possible to form an undercut geometry. By means of the projections the forces occurring during the clamping of a workpiece are introduced at least pre-ponderantly as compressive stresses into the filling material. Thus, the filling material is advantageously loaded and a compact design of the interface between guide device and chuck body can be implemented. In a further development of the invention, the recess has a profiling with an at least substantially constant cross-section and one profile axis is at least substantially radially oriented. The recess for receiving the guide device is preferably made in the chuck body by a milling process. An undercut can be inexpensively produced by using a profile cutter, which for example has a T-shaped cross-section. As the profile cutter in simple manner permits the manufacture of a profile with a constant cross-section, this ensures an inexpensive production of the recess a profile axis of the profile describes the space direction in which the profile has a constant cross-section. This profile axis is preferably radially oriented, based on the substantially cylindrically shaped chuck body or based on a rotation axis of the chuck body during filling to a machine spindle. Thus, the at least one guide device during the manufacture of the chuck can be inserted for example radially inwardly into the chuck body, where it is integrally fixed through the filling material. In a further development of the invention, the guide device and clamping holder bound at least one guide area preferably extending parallel to a radial direction and which is constructed for receiving at least one guide means. In a preferred development of the invention the guide area is oriented parallel to the radial direction of the chuck body and consequently permits a linear, radial adjustment of the clamping holder. The guide area is advantageously provided for receiving a bearing means. The bearing means can be a slide rail fixable to the guide device or the clamping holder. The bearing means can also have bearing or rolling members, particularly bearing balls or bearing needles received so as to move in a relative manner between the guide device and clamping holder. The bearing means constitutes a low friction, force-transferring, movable connection between the clamping holder and guide device. The clamping holder is advantageously mounted by means of a rolling guide in the guide device or the guide parts of the guide device and preferably the aforementioned bearing means or rolling members of the rolling guide are cylindrical rollers, with balls or needles as alternatives. The rolling members can form a rolling guide, so that the clamping holder is exclusively movable in a longitudinal direction of the rolling guide. The guide faces for the rolling members can be inclined to a centre axis of the chuck in order to ensure a reliable retention of the clamping holder. In particularly advantageous manner such guide faces are provided on the guide parts. In a further development of the invention, the guide device is formed from at least two and preferably at least substantially identically shaped guide parts. This permits an inexpensive, precise production of the guide device. The guide parts can be produced as sections of a profile made by rolling, extrusion or continuous casting. Finish machining of the sections can in particular take place by longitudinal grinding, so that a high surface quality can be obtained. The at least two guide parts are subsequently joined together and consequently form the guide device. In a preferred embodiment of the invention the guide parts are constructed and/or arranged homologously to a symmetry plane, particularly homologously to a radial plane of the chuck body. In a further development of the invention, the guide parts are coupled together by joining means, at least on insertion or during casting and optionally also permanently thereafter. The joining means can in particular be constituted by screw couplings. Screw couplings ensure an easily installed, highly loadable connection of the guide parts. The guide parts can alternatively or additionally be provided with precisely implemented and positioned positioning holes, which are intended for receiving fitting pins, so as to permit a particularly exact orientation of the mutually facing guide parts. The joining means are mainly used for fixing the guide parts until the guide means can be cast in the chuck body. Following casting the joining means are used for absorbing internal stresses on the joined together guide parts, such as can arise through the introduced clamping forces. It is also possible to remove the joining means following casting. According to a further development of the invention, the clamping holder for fixing a workpiece is coupled to an operating device constructed for introducing radially inwardly directed operating forces onto the clamping holder. The operating device makes it possible to fix the workpiece to the chuck, in that the forces necessary for fixing are preferably introduced onto the clamping holder in synchronous manner by the operating device. In a further development of the invention, the operating device is constructed for controlling the clamping holder by means of an operating member, particularly a wedge hook gear adjustable parallel to a machine spindle axis. Thus, use can be made of the operating member normally present in the case of a machine spindle in order to apply the clamping force necessary for workpiece fixing. The operating member is moved in translatory manner along the rotation axis of the machine spindle by a working cylinder associated with the machine tool. A transformation of the translatory movement along the rotation axis into a translatory movement of the clamping holder in the radial direction and therefore orthogonal to the rotation axis can preferably be implemented with a wedge hook gear. Corresponding oblique planes of the wedge hook gear and the clamping holder are so linearly displaced against one another that there is a movement deflection by 90 ø and the clamping holders move radially. According to another fundamental aspect of the invention, a method for manufacturing a chuck involves the steps of receiving guide parts on an orienting means, fitting and fixing the orienting means on the chuck body using at least one orientation geometry provided on the chuck body and corresponding to the orienting means, inserting the guide parts in recesses of the chuck body and integral joining of the guide parts to the chuck body. These method steps can be performed in different orders, so that the method can be adapted to different framework conditions. In a preferred method sequence, firstly the guide devices are moved radially inwards into the radially oriented recesses of the chuck body. An axial insertion is prevented by the projections on the guide devices and on the recesses. The orienting device is then oriented relative to the chuck body and fixed. A central hole which is in any case provided on the chuck body can thereby be used as the orientation geometry. The orienting device has arms which are matched to the positions of the recesses and the design of the guide devices and to which the latter are fitted. This gives a predetermined positioning of the guide devices relative to the chuck body. According to an advantageous procedure the gaps between the guide devices and the chuck body are then filled with filling material, which is then hardened. For filling the gaps use is preferably made of a viscous or pasty filling material to prevent the filling material being undesirably dispersed in the chuck body. These are specified in an exemplified manner. After hardening the filling material the orienting device is removed and the guide devices are integrally received on the chuck body. These and further features can be gathered from the claims, description and drawings and the individual features, both singly or in the form of subcombinations, can be implemented in an embodiment of the invention and in other fields and can represent advantageous, independently protectable constructions for which protection is claimed here. The subdivision of the application into individual sections and the subheadings in no way restrict the general validity of the statements made thereunder. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention are diagrammatically represented in the drawings and are explained in greater detail hereinafter. In the drawings show: FIG. 1 A perspective view of a chuck with three guide devices having the same angular spacing. FIG. 2 A part sectional detail enlargement of the chuck of FIG. 1. FIG. 3 A plan view of a chuck similar to FIGS. 1 and 2. FIG. 4 A lateral sectional representation along the section path I-I in FIG. 3. FIG. 5 A variant of a chuck in a view corresponding to FIG. 4 with a rolling guide. DETAILED DESCRIPTION OF THE EMBODIMENTS A chuck 10 has a chuck body 12 and a coupling member 14. Both the chuck body 12 and coupling member 14 have a substantially cylindrical shape and are positioned coaxially to a common centre axis 16. The chuck body 12 and coupling member 14 are provided with central through holes 18 oriented coaxially to the centre axis 16. On a not shown, front face remote from the chuck body 12 the coupling member 14 has a coupling geometry, which can be used for a centred fitting on a not shown machine spindle of a lathe. In the chuck body 12 there are three T-shaped profiled recesses 20 with an angular spacing of 120° based on the centre axis 16. Profile axes 22 extending in the direction of a constant profile cross-section of recesses 20, are oriented radially to chuck body 12. In each case guide devices 24 are integrally fixed in recesses 20. The guide devices 24 in each case have two substantially identically shaped guide parts 26 arranged homologously to profile axis 22 and which with respect to the latter have a constant cross-section. Polymer concrete 46 is introduced as filling material into the gap 40 between recess 20 and guide device 24. The guide devices 24 have an outer surface and an inner surface with in each case a T-shaped cross-section. As stated hereinbefore, said cross-section need not be T-shaped. The outer surface has a cross-section adapted to recess 20 and which is sectionally wider than a minimum cross-section of recess 20. Projections 28 formed bilaterally on guide device 24 can consequently transmit compressive forces via the polymer concrete 46 to the projections 30 of recess 20. The projections 30 of recess 20 in each case form undercuts. The profiling of the inner surfaces of guide parts 26 through inwardly projecting projections 32 also forms undercuts, which are constructed for a positive, slidable reception of the clamping holder 34. The clamping holders 34 profiled in T-shaped manner in the direction of profile axis 22 are frontally provided with a terminating surface 36, which is provided as a stop for not shown sliding blocks receivable in the T-shaped groove 42 of clamping holders 34. The sliding blocks are used for fixing not shown clamping means, which can be mounted on the top of the clamping holders 34 provided with a toothed system 38 and which are intended to provide a contact and a force transfer with a not shown workpiece. The clamping holders 34 can be subject to radially inwardly or outwardly directed clamping forces by a not shown wedge hook gear integrated into the coupling member in order to clamp the workpiece. It is generally also possible to use lever gears or key bar gears. The reaction forces on the clamping holders 34 resulting from the clamping forces lead to a tilting moment about a tilting axis 44 oriented orthogonally to centre axis 16 and to profile axis 22. In addition, the clamping holders 34 are subject to radially outwardly acting shear forces transmitted by the clamping means. The shear forces are transferred directly to the wedge hook gear and therefore play no important part with regards to the force transfer between clamping holders 34, guide device 24, polymer concrete 46 and chuck body 12. The forces transferred to clamping holders 34 by the tilting moment about tilting axis 44 must be introduced via the guide device and polymer concrete into the chuck body 12. In a radially external area of the guide device 24, the tilting moment gives rise to a compressive force 48 directed axially towards the coupling body 14. Guide device 24, via polymer concrete 46, introduces said compressive force 48 into the chuck body 12. However, in a radially inner area of guide device 24, there is an axially directed compressive force 50 resulting from the tilting moment and which is directed away from the coupling body 14. This compressive force 50, via the projections 28 of guide parts 26 and polymer concrete 46 is transferred to the projections 30 of chuck body 12. This ensures that the polymer concrete 46 is essentially only subject to compressive forces, so that even high tilting moments can be led off into the chuck body 12. As is shown in greater detail in FIGS. 2 and 4, the guide devices 24 are constructed as a slideway for the clamping holders 34, the T-shaped grooves in the guide devices 24 being matched to the T-shaped outer contour of clamping holders 34. Thus, in this embodiment of the invention, the guide area is limited to a sliding gap necessary for the sliding movement between clamping holders 34 and guide device 24. The guide parts 26 are interconnected by joining means on the form of clamp bolts 52. The clamp bolt is passed through a through hole 54 in the first guide part 26 and engages in a tapped hole 56 in the second guide part 26. Radially inwards is provided a second, not shown clamp bolt, which engages through a through hole provided in the second guide part 26 in a tapped hole in the first guide part 26. Through such an arrangement of the clamp bolts the guide parts 26 can be in the form of identical parts arranged homologously to a symmetry plane embracing the profile axis 22 in the radial direction. FIG. 5 shows a variant of a chuck 10′, where once again a guide device 24′ is positioned and secured in a recess 20′ of chuck body 12′, particularly by introducing polymer concrete into the gap 40′. Clamping holder 34′ has in the vicinity of projections 32 according to FIG. 4 cylindrical rollers 62′ as rolling members and which are fixed to the clamping holder 34′. Correspondingly on the inside of guide parts 26′ there are inclined faces 60′ as guide faces for the rolling members 62′. Through the provision of rolling members 62′ and the inclined arrangement there is an easy guidance and also an absorption of forces along the centre axis 60′ and in the plane normal thereto. The advantage of the rolling guide is in particular the lower friction and a permanently wear-resistant operation. In place of the cylindrical rolling members 62′ shown, it would also be possible to use other rolling members, for example balls. The advantage of fixing the rolling members 62′ to the removable clamping holder 34′ is easier maintenance and replaceability. The precise nature of fixing and arranging the rolling members 62′ gives rise to no problem for the expert and for this purpose he can make use of known prior art solutions. Besides such a lateral rolling guide it would also be possible to have a rolling guide on the underside of the clamping holder 34′.
|
B
|
B23
|
B23B
|
5
|
22
|
|||
11915921
|
US20090309117A1-20091217
|
PROTECTION CIRCUIT, AND SEMICONDUCTOR DEVICE AND LIGHT EMITTING DEVICE USING SUCH PROTECTION CIRCUIT
|
ACCEPTED
|
20091202
|
20091217
|
[]
|
H01L3300
|
["H01L3300", "H01L2973", "H02H900"]
|
7889467
|
20071129
|
20110215
|
361
|
056000
|
95717.0
|
JACKSON
|
STEPHEN
|
[{"inventor_name_last": "Okazaki", "inventor_name_first": "Mitsuru", "inventor_city": "Kyoto", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Takahashi", "inventor_name_first": "Naoki", "inventor_city": "Kyoto", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Shimizu", "inventor_name_first": "Akira", "inventor_city": "Kyoto", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Nakata", "inventor_name_first": "Kenichi", "inventor_city": "Kyoto", "inventor_state": "", "inventor_country": "JP"}]
|
In a protection circuit connected, via lines including an inductance component, to a circuit to be protected, a first transistor is arranged on a path to ground from a connection point of the protection circuit and the line. A second transistor is arranged on a path to ground from a connection point of the circuit to be protected and the line, and extracts, from a connection point, a current corresponding to a current flowing in the first transistor. The first and the second transistors are NPN bipolar transistors having a base and an emitter are commonly connected. A resistor is connected between the base and the emitter of the first transistor, and a diode is connected between the base and a collector.
|
1. A protection circuit connected via a line including a significant inductance component to a circuit to be protected, comprising: a first transistor arranged on a path to ground from a connection point of the protection circuit and the line; and a second transistor arranged on a path to ground from a connection point of the circuit to be protected and the line, the second transistor extracting, from the connection point, a current corresponding to a current flowing in the first transistor. 2. A protection circuit according to claim 1, wherein the first and the second transistors are bipolar transistors having a base and an emitter commonly connected. 3. A protection circuit according to claim 2, wherein the first and the second transistors are NPN bipolar transistors, a collector of the first transistor being connected to a connection point of the protection circuit and the wire, a collector of the second transistor being connected to a connection point of the circuit to be protected and the wire, and a commonly connected emitter being grounded, the protection circuit further comprising: a resistor arranged between a base and an emitter of the first transistor; and a diode with a cathode connected to the collector of the first transistor, and an anode connected to the base of the first transistor. 4. A protection circuit according to claim 1, wherein transistor sizes of the first and the second transistor are configured to be approximately the same. 5. A protection circuit according to claim 1, wherein the protection circuit is integrated on a same semiconductor substrate as the circuit to be protected, and the circuit to be protected and the protection circuit are each provided with bonding pads; and the respective bonding pads are connected by a bonding wire equivalent to the wire, via a terminal arranged on a base on which the semiconductor substrate is mounted. 6. A semiconductor device comprising: a driver circuit which is connected to a cathode of a light emitting diode and which controls emitted quantity of light of the light emitting diode; and the protection circuit according to claim 1, provided with the driver circuit as the circuit to be protected. 7. A light emitting apparatus comprising: a light emitting diode; and a semiconductor device according to claim 6, which drives the light emitting diode.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to circuit protection technology for protecting a circuit to be protected, from surge voltages and the like. 2. Description of the Related Art Many semiconductor integrated circuits are used in various electronic devices, starting from mobile telephones, PDAs (Personal Digital Assistants), and laptop personal computers, or electrical systems in automobiles. Since usage in all kinds of conditions is envisaged for such semiconductor integrated circuits, high reliability is required. In order to improve reliability, in general, a protection circuit is provided for each bonding pad of an input-output terminal connected to the outside of a circuit. Among such protection circuits, a voltage clamp circuit may be provided so that the reliability of an internal circuit that is to be protected (referred to as a protected circuit, below), does not deteriorate, even in cases in which a surge voltage or the like is precipitously applied. Circuit protection technology by this kind of voltage clamp circuit is described, for example, in Patent Document 1. Here, as an example, a protection circuit of a driver circuit 200 of an LED (Light Emitting Diode) shown in FIG. 1 is examined. The LED driver circuit 200 is, for example, a circuit for driving the LED 24 provided as illumination of a meter of an automobile. A battery voltage outputted from a battery 20 is applied via a resistor 22 to an anode of the LED 24 . Furthermore, for the cathode of the LED 24 , there is a connection to a drive transistor M 1 of the LED driver circuit 200 . A controller 26 controls gate voltage of the drive transistor M 1 , and, by regulating current flowing in the LED 24 , controls emitted light intensity of the LED 24 . Since voltage outputted from the battery 20 is unstable, for a semiconductor integrated circuit used for this type of application, reliability is required particularly against surge voltages and the like. At the same time, in the LED driver circuit 200 of FIG. 1 , breakdown voltage of the drive transistor M 1 becomes a problem. Accordingly, a protection circuit 100 , which clamps voltage applied to a drain of the drive transistor M 1 , is arranged in parallel to the drive transistor M 1 . Patent Document 1: Japanese Patent Application, Laid Open No. H6-140576 FIG. 2 is a plan view of the LED driver circuit 200 of FIG. 1 seen from above. The LED driver circuit 200 is integrated on a semiconductor substrate 30 , and the semiconductor substrate 30 is mounted on a base 32 for a package. A protected circuit 110 integrated on the semiconductor substrate 30 includes a drive transistor M 1 of FIG. 1 . With regard to the drive transistor M 1 , which is the protected circuit 110 , since it is necessary to inspect breakdown voltage in a state in which the protection circuit 100 is not used, that is, as a single unit, a dedicated bonding pad 34 is provided. The protection circuit 100 also is provided with another bonding pad 36 , and the protection circuit 100 and the protected circuit 110 are connected to one another by bonding wires W 1 and W 2 , via a bonding pad 38 arranged on the base 32 . The bonding pad 38 is connected to an external electrode of a package, and this external electrode is connected to a cathode of the LED 24 of FIG. 1 . In this way, the protection circuit 100 and the protected circuit 110 are connected via the bonding wires W 1 and W 2 , which are lines that include a significant inductance component. FIG. 3 is an equivalent circuit diagram of the LED driver circuit 200 of FIG. 1 . The protection circuit 100 is provided with a first transistor Q 1 , a diode D 1 , and a resistor R 3 . The first transistor Q 1 is an NPN bipolar transistor, and is arranged on a path to ground, from the bonding pad 34 , which is a connection point of the present protection circuit 100 and the bonding wire W 1 . The diode D 1 is connected between a base and a collector of the first transistor Q 1 , and the resistor R 3 is arranged between the base and an emitter of the first transistor Q 1 . In the figure, C 1 and C 2 represent parasitic capacitances in the LED driver circuit 200 ; the parasitic capacitance C 1 is mainly collector-emitter capacitance of the first transistor Q 1 of the protection circuit 100 , and the parasitic capacitance C 2 is drain-source capacitance of the drive transistor M 1 inside the protected circuit 110 . Furthermore, the bonding wires W 1 and W 2 respectively include resistance components R 1 and R 2 , and inductance components L 1 and L 2 . Included in the resistance components R 1 and R 2 are not only the bonding wires W 1 and W 2 , but also IC chip internal wiring resistance. When voltage of the bonding pad 38 rises due to occurrence of a surge voltage, voltage Va of the bonding pad 34 rises therewith. When the voltage Va of the bonding pad 34 exceeds a Zener voltage Vz of the diode D 1 , a reverse current directed from cathode to anode flows, the first transistor Q 1 is ON, and a current is extracted from the bonding pad 34 . As a result, voltages Va and Vb of the bonding pad 34 and the bonding pad 36 are clamped, and it is possible to prevent application of a high voltage to the protected circuit 110 . With the protection circuit 100 configured in this way, problems described below arise. FIG. 4 is a voltage waveform diagram of the LED driver circuit 200 of FIG. 3 , and shows a time waveform of the voltage Va of the bonding pad 34 and the voltage Vb of the bonding pad 36 of FIG. 3 . At time T 0 , when a surge voltage is inputted from the bonding pad 38 , both of the voltages Va and Vb of the bonding pad 34 and 36 rise. When the voltage Va of the bonding pad 34 rises and exceeds the Zener voltage Vz of the diode D 1 , a reverse current directed from cathode to anode of the diode D 1 flows, and the first transistor Q 1 is ON. If base-emitter voltage of the first transistor Q 1 is taken as Vbe, the voltage Va of the bonding pad 34 is clamped close to Vmax=Vz+Vbe, as shown in FIG. 4 . However, as shown in FIG. 3 , parasitic capacitances of different capacitance values exist for each of the bonding pad 34 and the bonding pad 36 . If C 1 >C 2 , charge stored in the parasitic capacitance C 2 of the protected circuit 110 is extracted by the protection circuit 100 . At this time, the charge stored in the parasitic capacitance C 2 is discharged by the protection circuit 100 via the bonding wires W 1 and W 2 , which include the inductance components L 1 and L 2 . By a current flowing in the inductance components L 1 and L 2 , LCR resonance is generated by the parasitic capacitances C 1 and C 2 , the resistors R 1 and R 2 , and the inductance components L 1 and L 2 included in the bonding wires W 1 and W 2 , and a reverse voltage is generated with respect to the inductance components L 1 and L 2 . As a result, the voltage Vb of the bonding pad 36 rises while oscillating, and the oscillation continues even after time T 1 at which the voltage Va of the bonding pad 34 is clamped at the voltage Vmax. As a result, for the protected circuit 110 , there have been cases in which voltage exceeding the voltage Vmax is applied, and there has been room for improvement in functionality of the protection circuit 100 .
|
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been made in view of these problems, and a general purpose thereof is to provide a protection circuit which enables a voltage clamp that suppresses oscillation, and also a semiconductor device using the protection circuit. An embodiment of the present invention relates to a protection circuit connected, via a line including a significant inductance component, to a circuit to be protected. The protection circuit is provided with a first transistor arranged on a path to ground from a connection point of the protection circuit and the line, and a second transistor arranged on a path to ground from a connection point of the circuit to be protected and the line, the second transistor extracting, from the connection point, a current corresponding to a current flowing in the first transistor. The “significant inductance component” is an inductance component of a level forming an oscillation circuit and a parasitic capacitance within a circuit. According to the embodiment, when a surge voltage occurs, a current due to the second transistor in addition to the first transistor is extracted. As a result, since a current is extracted from both ends of a wire including the significant inductance component, LCR oscillation can be suppressed, and voltage oscillation can be suppressed. The first and the second transistors may be bipolar transistors whose base and emitter are commonly connected. In such cases, by adjusting size ratio of the first transistor and the second transistor, a constant current in accordance with the size ratio of the transistors can be extracted. The first and the second transistors are NPN bipolar transistors; a collector of the first transistor may be connected to a connection point of the protection circuit and the wire; a collector of the second transistor may be connected to a connection point of the circuit to be protected and the wire; and a commonly connected emitter may be grounded. The protection circuit may be further provided with a resistor arranged between a base and an emitter of the first transistor, and a diode, with a cathode connected to a collector of the first transistor, and an anode connected to the base of the first transistor. Transistor sizes of the first and the second transistor may be configured to be approximately the same. By the size of the first and the second transistors being approximately the same, electrical current amount extracted by each of the transistors can be made approximately equal, and it is possible to suppress oscillation. The protection circuit may be integrated on the same semiconductor substrate as the circuit to be protected; the circuit to be protected and the protection circuit may each be provided with bonding pads; and each of the bonding pads may be connected by a bonding wire equivalent to the wire, via a terminal arranged on a base on which the semiconductor substrate is mounted. Another embodiment of the present invention is a semiconductor device. The device is provided with a driver circuit, which is connected to a cathode of a light emitting diode, and which controls emitted quantity of light of the light emitting diode, and with the abovementioned protection circuit provided with the driver circuit as the circuit to be protected. According to this embodiment, the driver circuit can be protected from a surge voltage and the like, and it is possible to raise reliability of the semiconductor device. It is to be noted that any arbitrary combination or rearrangement of the above-described structural components and so forth is effective as and encompassed by the present embodiments. Moreover, this summary of the invention does not necessarily describe all necessary features so that the invention may also be a sub-combination of these described features.
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to circuit protection technology for protecting a circuit to be protected, from surge voltages and the like. 2. Description of the Related Art Many semiconductor integrated circuits are used in various electronic devices, starting from mobile telephones, PDAs (Personal Digital Assistants), and laptop personal computers, or electrical systems in automobiles. Since usage in all kinds of conditions is envisaged for such semiconductor integrated circuits, high reliability is required. In order to improve reliability, in general, a protection circuit is provided for each bonding pad of an input-output terminal connected to the outside of a circuit. Among such protection circuits, a voltage clamp circuit may be provided so that the reliability of an internal circuit that is to be protected (referred to as a protected circuit, below), does not deteriorate, even in cases in which a surge voltage or the like is precipitously applied. Circuit protection technology by this kind of voltage clamp circuit is described, for example, in Patent Document 1. Here, as an example, a protection circuit of a driver circuit 200 of an LED (Light Emitting Diode) shown in FIG. 1 is examined. The LED driver circuit 200 is, for example, a circuit for driving the LED 24 provided as illumination of a meter of an automobile. A battery voltage outputted from a battery 20 is applied via a resistor 22 to an anode of the LED 24. Furthermore, for the cathode of the LED 24, there is a connection to a drive transistor M1 of the LED driver circuit 200. A controller 26 controls gate voltage of the drive transistor M1, and, by regulating current flowing in the LED 24, controls emitted light intensity of the LED 24. Since voltage outputted from the battery 20 is unstable, for a semiconductor integrated circuit used for this type of application, reliability is required particularly against surge voltages and the like. At the same time, in the LED driver circuit 200 of FIG. 1, breakdown voltage of the drive transistor M1 becomes a problem. Accordingly, a protection circuit 100, which clamps voltage applied to a drain of the drive transistor M1, is arranged in parallel to the drive transistor M1. Patent Document 1: Japanese Patent Application, Laid Open No. H6-140576 FIG. 2 is a plan view of the LED driver circuit 200 of FIG. 1 seen from above. The LED driver circuit 200 is integrated on a semiconductor substrate 30, and the semiconductor substrate 30 is mounted on a base 32 for a package. A protected circuit 110 integrated on the semiconductor substrate 30 includes a drive transistor M1 of FIG. 1. With regard to the drive transistor M1, which is the protected circuit 110, since it is necessary to inspect breakdown voltage in a state in which the protection circuit 100 is not used, that is, as a single unit, a dedicated bonding pad 34 is provided. The protection circuit 100 also is provided with another bonding pad 36, and the protection circuit 100 and the protected circuit 110 are connected to one another by bonding wires W1 and W2, via a bonding pad 38 arranged on the base 32. The bonding pad 38 is connected to an external electrode of a package, and this external electrode is connected to a cathode of the LED 24 of FIG. 1. In this way, the protection circuit 100 and the protected circuit 110 are connected via the bonding wires W1 and W2, which are lines that include a significant inductance component. FIG. 3 is an equivalent circuit diagram of the LED driver circuit 200 of FIG. 1. The protection circuit 100 is provided with a first transistor Q1, a diode D1, and a resistor R3. The first transistor Q1 is an NPN bipolar transistor, and is arranged on a path to ground, from the bonding pad 34, which is a connection point of the present protection circuit 100 and the bonding wire W1. The diode D1 is connected between a base and a collector of the first transistor Q1, and the resistor R3 is arranged between the base and an emitter of the first transistor Q1. In the figure, C1 and C2 represent parasitic capacitances in the LED driver circuit 200; the parasitic capacitance C1 is mainly collector-emitter capacitance of the first transistor Q1 of the protection circuit 100, and the parasitic capacitance C2 is drain-source capacitance of the drive transistor M1 inside the protected circuit 110. Furthermore, the bonding wires W1 and W2 respectively include resistance components R1 and R2, and inductance components L1 and L2. Included in the resistance components R1 and R2 are not only the bonding wires W1 and W2, but also IC chip internal wiring resistance. When voltage of the bonding pad 38 rises due to occurrence of a surge voltage, voltage Va of the bonding pad 34 rises therewith. When the voltage Va of the bonding pad 34 exceeds a Zener voltage Vz of the diode D1, a reverse current directed from cathode to anode flows, the first transistor Q1 is ON, and a current is extracted from the bonding pad 34. As a result, voltages Va and Vb of the bonding pad 34 and the bonding pad 36 are clamped, and it is possible to prevent application of a high voltage to the protected circuit 110. With the protection circuit 100 configured in this way, problems described below arise. FIG. 4 is a voltage waveform diagram of the LED driver circuit 200 of FIG. 3, and shows a time waveform of the voltage Va of the bonding pad 34 and the voltage Vb of the bonding pad 36 of FIG. 3. At time T0, when a surge voltage is inputted from the bonding pad 38, both of the voltages Va and Vb of the bonding pad 34 and 36 rise. When the voltage Va of the bonding pad 34 rises and exceeds the Zener voltage Vz of the diode D1, a reverse current directed from cathode to anode of the diode D1 flows, and the first transistor Q1 is ON. If base-emitter voltage of the first transistor Q1 is taken as Vbe, the voltage Va of the bonding pad 34 is clamped close to Vmax=Vz+Vbe, as shown in FIG. 4. However, as shown in FIG. 3, parasitic capacitances of different capacitance values exist for each of the bonding pad 34 and the bonding pad 36. If C1>C2, charge stored in the parasitic capacitance C2 of the protected circuit 110 is extracted by the protection circuit 100. At this time, the charge stored in the parasitic capacitance C2 is discharged by the protection circuit 100 via the bonding wires W1 and W2, which include the inductance components L1 and L2. By a current flowing in the inductance components L1 and L2, LCR resonance is generated by the parasitic capacitances C1 and C2, the resistors R1 and R2, and the inductance components L1 and L2 included in the bonding wires W1 and W2, and a reverse voltage is generated with respect to the inductance components L1 and L2. As a result, the voltage Vb of the bonding pad 36 rises while oscillating, and the oscillation continues even after time T1 at which the voltage Va of the bonding pad 34 is clamped at the voltage Vmax. As a result, for the protected circuit 110, there have been cases in which voltage exceeding the voltage Vmax is applied, and there has been room for improvement in functionality of the protection circuit 100. SUMMARY OF THE INVENTION The present invention has been made in view of these problems, and a general purpose thereof is to provide a protection circuit which enables a voltage clamp that suppresses oscillation, and also a semiconductor device using the protection circuit. An embodiment of the present invention relates to a protection circuit connected, via a line including a significant inductance component, to a circuit to be protected. The protection circuit is provided with a first transistor arranged on a path to ground from a connection point of the protection circuit and the line, and a second transistor arranged on a path to ground from a connection point of the circuit to be protected and the line, the second transistor extracting, from the connection point, a current corresponding to a current flowing in the first transistor. The “significant inductance component” is an inductance component of a level forming an oscillation circuit and a parasitic capacitance within a circuit. According to the embodiment, when a surge voltage occurs, a current due to the second transistor in addition to the first transistor is extracted. As a result, since a current is extracted from both ends of a wire including the significant inductance component, LCR oscillation can be suppressed, and voltage oscillation can be suppressed. The first and the second transistors may be bipolar transistors whose base and emitter are commonly connected. In such cases, by adjusting size ratio of the first transistor and the second transistor, a constant current in accordance with the size ratio of the transistors can be extracted. The first and the second transistors are NPN bipolar transistors; a collector of the first transistor may be connected to a connection point of the protection circuit and the wire; a collector of the second transistor may be connected to a connection point of the circuit to be protected and the wire; and a commonly connected emitter may be grounded. The protection circuit may be further provided with a resistor arranged between a base and an emitter of the first transistor, and a diode, with a cathode connected to a collector of the first transistor, and an anode connected to the base of the first transistor. Transistor sizes of the first and the second transistor may be configured to be approximately the same. By the size of the first and the second transistors being approximately the same, electrical current amount extracted by each of the transistors can be made approximately equal, and it is possible to suppress oscillation. The protection circuit may be integrated on the same semiconductor substrate as the circuit to be protected; the circuit to be protected and the protection circuit may each be provided with bonding pads; and each of the bonding pads may be connected by a bonding wire equivalent to the wire, via a terminal arranged on a base on which the semiconductor substrate is mounted. Another embodiment of the present invention is a semiconductor device. The device is provided with a driver circuit, which is connected to a cathode of a light emitting diode, and which controls emitted quantity of light of the light emitting diode, and with the abovementioned protection circuit provided with the driver circuit as the circuit to be protected. According to this embodiment, the driver circuit can be protected from a surge voltage and the like, and it is possible to raise reliability of the semiconductor device. It is to be noted that any arbitrary combination or rearrangement of the above-described structural components and so forth is effective as and encompassed by the present embodiments. Moreover, this summary of the invention does not necessarily describe all necessary features so that the invention may also be a sub-combination of these described features. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which: FIG. 1 is a circuit diagram of a driver circuit of a general LED provided with a protection circuit; FIG. 2 is a plan view seen from above, of the LED driver circuit of FIG. 1; FIG. 3 is an equivalent circuit diagram of the LED driver circuit of FIG. 1; FIG. 4 is a voltage waveform diagram of the LED driver circuit of FIG. 3; FIG. 5 is a circuit diagram showing a configuration of the LED driver circuit including the protection circuit according to an embodiment of the present invention; and FIG. 6 is an operation waveform diagram of the LED driver circuit of FIG. 5. DETAILED DESCRIPTION OF THE INVENTION The invention will now be described based on preferred embodiments which do not intend to limit the scope of the present invention but exemplify the invention. All of the features and the combinations thereof described in the embodiment are not necessarily essential to the invention. A protection circuit 100 according to the present embodiment is used, for example, in an LED driver circuit 200 described in FIG. 1. As shown in FIG. 2, also in the present embodiment, the protection circuit 100 and a protected circuit 110, that is to be protected, are integrated on the same semiconductor substrate 30, and the protection circuit 100 and the protected circuit 110 are respectively provided with bonding pads 34 and 36. The bonding pads 34 and 36 are connected by bonding wires W1 and W2 that are lines including significant inductance components, via a bonding pad 38 arranged on a base 32, on which the semiconductor substrate 30 is mounted. FIG. 5 is a circuit diagram showing a configuration of the LED driver circuit 200 including the protection circuit 100 according to the present embodiment. The LED driver circuit 200 includes the protection circuit 100 and the protected circuit 110, and the protection circuit 100 and the protected circuit 110 are connected via the bonding wires W1 and W2 that include inductance components L1 and L2. The inductance components L1 and L2 included in the bonding wires W1 and W2 are dependant upon bonding wire length and thickness, but since the inductance components are normally less than or equal to 1 nH or of the order of 1 nH, an undesired LCR oscillation circuit is formed due to a combination of another capacitance component and resistance component. The protection circuit 100 is provided with a first transistor Q1, a second transistor Q2, a diode D1, and a resistor R3. The first transistor Q1 is an NPN bipolar transistor, and is arranged on a path to ground, from the bonding pad 34, which is a connection point of the protection circuit 100 and the bonding wire W1; an emitter thereof is grounded and a collector is connected to a bonding pad 34. The diode D1 is arranged between a base and the collector of the first transistor Q1; a cathode thereof is connected to the collector of the first transistor Q1, and an anode thereof is connected to the base of the first transistor Q1. Furthermore, the resistor R3 is arranged between the base and the emitter of the first transistor Q1. The second transistor Q2 is an NPN bipolar transistor similar to the first transistor Q1, and is arranged on a path to ground, from the bonding pad 36, which is a connection point of the protected circuit 110 and the bonding wire W2. An emitter of the second transistor Q2 is grounded, and a collector is connected to the bonding pad 36. The bases and the emitters of the first transistor Q1 and the second transistor Q2 are commonly connected. In the present embodiment, transistor sizes of the first transistor Q1 and the second transistor Q2 are configured to be approximately the same. As a result, the second transistor Q2 extracts a current of the same amount as a current flowing in the first transistor Q1, from the bonding pad 36. In the figure, C1 to C3 represent parasitic capacitances in the LED driver circuit 200. The parasitic capacitance C1 is mainly capacitance between the collector and the emitter of the first transistor Q1 of the protection circuit 100; the parasitic capacitance C2 is mainly capacitance between a drain and a source of a drive transistor M1 inside the protected circuit 110; and parasitic capacitance C3 is mainly capacitance between the collector and the emitter of the second transistor Q2 of the protection circuit 100. That is, the parasitic capacitance C1 exists between the bonding pad 34 and ground, and a parasitic capacitance (C2+C3) exists between the bonding pad 36 and ground. Here, in cases in which C2<C1 holds, since the sizes of the first transistor Q1 and the second transistor Q2 are configured to be the same, C1≈(C2+C3) holds. In this way, the capacitance between the bonding pad 34 and ground, and the capacitance between the bonding pad 36 and ground are approximately equal. An explanation will be given concerning operation of the LED driver circuit 200 configured as above. FIG. 6 is an operation waveform diagram of the LED driver circuit 200 of FIG. 5. At time T0, when a surge voltage is inputted from the bonding pad 38, voltage of the bonding pad 38 rises, and accompanying this, voltage Va of the bonding pad 34 and voltage Vb of the bonding pad 36 rise. When the voltage Va of the bonding pad 34 rises and exceeds a Zener voltage Vz of the diode D1, a reverse current directed from cathode to anode of the diode D1 flows, and the first transistor Q1 is ON. As described above, the transistor sizes of the first transistor Q1 and the second transistor Q2 are configured to be approximately the same, so that the parasitic capacitances of the bonding pad 34 and the bonding pad 36 are approximately equal. Parasitic capacitance values being equal means that charge amounts stored when electrical potential is the same are approximately equal, so that it is possible to reduce transfer of charge via the inductance components L1 and L2 between the parasitic capacitances. As a result, the LCR oscillation, which occurs when the voltage Vb of the bonding pad 36 rises with a rise in the voltage Va of the bonding pad 34, is suppressed, and the voltage Vb of the bonding pad 36 does not oscillate, but rises, following the voltage Va of the bonding pad 34. As described above, the transistor sizes of the first transistor Q1 and the second transistor Q2 are configured to be approximately the same, so that a current Iq1 flowing in the first transistor Q1 and a current Iq2 flowing in the second transistor Q2 are approximately equal. As a result, even after the voltages Va and Vb of the bonding pads 34 and 36 reach Vmax=Vz+Vbe at time T1 and are clamped, the same amount of current is extracted from the bonding pad 34 and the bonding pad 36. By continually extracting approximately the same amount of current from the bonding pad 34 and the bonding pad 36, even after time T1, it is possible to prevent the voltage Vb of the bonding pad 36 fluctuating due to the LCR oscillation. In this way, according to the protection circuit 100 according to the present embodiment, it is possible to suppress oscillation of the voltage Vb applied to the protected circuit 110, and to clamp the voltage at a predetermined voltage Vmax; it is possible to prevent voltage greater than or equal to the predetermined voltage Vmax from being applied to the protected circuit 110, and to provide more secure protection. This embodiment is an example; various modified examples of combinations of various component elements and various processes thereof are possible, and a person skilled in the art will understand that such modified examples are within the scope of the present invention. For example, in the protection circuit 100 of FIG. 5, the first transistor Q1 and the second transistor Q2 may be PNP bipolar transistors. In such cases, by connecting the resistor R3 between the base and the emitter, and the diode D1 between the base and the collector, it is possible to clamp the voltage of the bonding pads 34 and 36. Furthermore, in the protection circuit 100, the diode D1 may be connected in multiple stages between the base and the collector of the first transistor Q1. The clamp voltage can be according to the number of stages of the diode D1. Furthermore, a resistance element or a diode may be arranged on a current path form of the first transistor Q1 or the second transistor Q2. There are different variations of format of the protection circuit 100, and the circuit format thereof is not particularly limited to the circuit diagram shown in FIG. 5; the first transistor Q1 may be arranged on a path to ground from the bonding pad 34 and may be ON in an overvoltage state, and the second transistor Q2 may be arranged in parallel to the first transistor Q1, and may be provided on a path to ground from the bonding pad 36. In the embodiment, an explanation has been given concerning cases in which transistor sizes of the first transistor Q1 and the second transistor Q2 are configured to be approximately the same. Here, “approximately the same” means sizes at which inhibition of the LCR oscillation is possible; for example, if in a range of ½ to double, it is possible to adequately inhibit the LCR oscillation. Furthermore, even if the size ratio of the first transistor Q1 and the second transistor Q2 is outside this range, the voltage Vb of the bonding pad 36 may oscillate a little, but compared to cases in which the second transistor Q2 is not provided, it is possible to realize an effect in which the LCR oscillation is suppressed. Furthermore, in the embodiment, an explanation was given concerning cases in which the protection circuit 100 is arranged in the LED driver circuit, but there is no limitation thereto, and various circuits can be used in which the protection circuit and the protected circuit are connected via a line including a significant inductance component such as a bonding wire. In addition, in the embodiment an explanation has been given concerning cases in which the line that has the inductance component is a bonding wire, but there is no limitation thereto. For example, in cases of a wafer level CSP (Chip Size Package), the bonding pads 34 and 36 are connected by post and rewiring. In such cases, since the post and rewiring include the inductance component, by using the protection circuit 100 according to the present embodiment, it is possible to preferably suppress the LCR oscillation. While the preferred embodiments of the present invention have been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the appended claims.
|
H
|
H01
|
H01L
|
33
|
00
|
|||
11668039
|
US20080180020A1-20080731
|
LIGHT-EMITTING DISPLAY DEVICE HAVING IMPROVED EFFICIENCY
|
ACCEPTED
|
20080716
|
20080731
|
[]
|
H01J163
|
["H01J163", "B05D506"]
|
7952105
|
20070129
|
20110531
|
257
|
079000
|
63495.0
|
TORNOW
|
MARK
|
[{"inventor_name_last": "Cok", "inventor_name_first": "Ronald S.", "inventor_city": "Rochester", "inventor_state": "NY", "inventor_country": "US"}]
|
A light-emissive device includes a substrate having a first electrode formed on the substrate. A colloidal light-emitting layer comprising inorganic, light-emissive particles is formed over the first electrode. A second electrode is formed over the light-emitting layer. At least one of the first and second electrodes is transparent. The transparent electrode preferably has a refractive index substantially equal to or greater than the refractive index of the colloidal light-emitting layer. Finally, a light-scattering layer is formed on a side of the transparent electrode opposite the colloidal light-emitting layer.
|
1. A light-emissive device comprising: a substrate; a first electrode formed on the substrate; a colloidal light-emitting layer comprising inorganic, light-emissive particles formed over the first electrode; a second electrode formed over the light-emitting layer; wherein at least one of the first and second electrodes is transparent and wherein the transparent electrode has a refractive index substantially equal to or greater than the refractive index of the colloidal light-emitting layer; and a light-scattering layer formed on a side of the transparent electrode opposite the colloidal light-emitting layer. 2. The light-emissive device of claim 1, wherein the substrate is transparent and has a refractive index less than that of the transparent electrode and the light-emitting layer. 3. The light-emissive device of claim 1, wherein the first electrode is transparent and the second electrode comprises a transparent, conductive layer and a reflective conductive layer, and wherein the light-scattering layer is formed on only a first portion of the transparent conductive layer between the transparent conductive layer and the reflective conductive layer, and the reflective conductive layer is in electrical contact with the transparent conductive layer in a second portion of the transparent conductive layer. 4. The light-emissive device of claim 3, further comprising a protective layer formed between the transparent, conductive layer and the light-scattering layer. 5. The light-emissive device of claim 4, wherein the protective layer is electrically conductive. 6. The light-emissive device of claim 1, wherein the second electrode is transparent and the first electrode comprises a transparent conductive layer and a reflective layer, and wherein the light-scattering layer is formed between the transparent, conductive layer and the reflective layer. 7. The light-emissive device of claim 1, wherein the first electrode and the substrate are transparent and further comprising a low-index layer having a refractive index lower than the substrate refractive index located between the transparent electrode and the substrate. 8. The light-emissive device of claim 1, wherein the low-index layer is an optical isolation cavity formed over the substrate wherein the transparent electrode or a second layer formed between the optical isolation cavity and the transparent electrode comprises one or more openings leading to the optical isolation cavity, and the cavity is formed by etching a sacrificial layer deposited between the substrate and the transparent electrode or the second layer through the one or more openings. 9. The light-emissive device of claim 1, wherein the second electrode is transparent and further comprising a transparent cover formed over the second electrode and a low-index layer having a refractive index lower than the cover refractive index located between the second electrode and the cover. 10. The light-emissive device of claim 9, wherein the low-index layer is a vacuum or the gap is filled with a relatively low-refractive index gas and the light-scattering layer comprises a plurality of relatively high-refractive index light-scattering transparent particles projecting into the gap without contacting the cover and further comprising an adhesive binder in contact with at least some of the light-scattering particles to adhere the light-scattering particles to the transparent electrode. 11. The light-emissive device of claim 1, further comprising a plurality of spaced-apart light-emitting elements emitting a common color of light, wherein the thickness of the substrate is less than or equal to twice the distance between the spaced apart light-emitting elements. 12. The light-emissive device of claim 1, wherein the light-emitting particles are quantum dots. 13. The light-emissive device of claim 1, wherein the light-emitting layer further comprises non-light-emitting, conductive particles. 14. The light-emissive device of claim 1, wherein the non-light-emitting, conductive particles are sintered to the light-emitting particles. 15. The light-emissive device of claim 1 further comprising one or more charge-injection, -transport, and/or -blocking layers formed between the light-emitting layer and either of the electrodes and wherein the charge-injection, -transport, and/or -blocking layers have an refractive index substantially equal to or greater than the light-emissive layer refractive index and substantially equal to or less than the transparent electrode refractive index. 16. The light-emissive device of claim 1 wherein the transparent electrode further comprises a transparent conductive layer and a transparent protective layer, and the transparent protective layer is located between the transparent conductive layer and the scattering layer. 17. The light-emissive device of claim 1 wherein the light-scattering layer has a thickness of between 300 nm and 3 microns. 18. The light-emissive device of claim 1 wherein the light-scattering layer comprises light-scattering particles and wherein the average ratio of the volume of light-scattering particles to the volume of the layer is greater than 0.55. 19. A method for making a light-emissive device, comprising the steps of: a. providing a substrate; b. forming a first electrode on the substrate; c. forming a dispersion comprising inorganic light emissive particles d. coating the dispersion over the first electrode to form a light-emitting layer comprising a colloid of inorganic, light-emissive particles; e. forming a second electrode over the light-emitting layer; wherein at least one of the first and second electrodes is transparent and wherein the transparent electrode has a refractive index substantially equal to or greater than the refractive index of the colloidal light-emitting layer; and f. forming a light-scattering layer on a side of the transparent electrode opposite the colloidal light-emitting layer. 20. The method claimed in claim 19, further comprising the step of providing a low-index layer between the transparent electrode and the substrate or between the transparent electrode and a cover provided to encapsulate the light emissive device.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Semiconductor light emitting diode (LED) devices, which are primarily inorganic, have been made since the early 1960's and currently are manufactured for usage in a wide range of consumer and commercial applications. The layers comprising the LEDs are based on crystalline semiconductor materials. These crystalline-based inorganic LEDs have the advantages of high brightness, long lifetimes, and good environmental stability. The crystalline semiconductor layers that provide these advantages also have a number of disadvantages. The dominant ones have high manufacturing costs; difficulty in combining multi-color output from the same chip; efficiency of light output; and the need for high-cost rigid substrates. In the mid 1980's, organic light-emitting diodes (OLEDs) were invented (Tang et al, Applied Physics Letter 51, 913 (1987)) based on the usage of small molecular weight molecules. In the early 1990's, polymeric LEDs were invented (Burroughs et al., Nature 347, 539 (1990)). In the ensuing 15 years organic-based LED displays have been brought out into the marketplace and there has been great improvements in device lifetime, efficiency, and brightness. For example, devices containing phosphorescent emitters have external quantum efficiencies as high as 19%; whereas, device lifetimes are routinely reported at many tens of thousands of hours. However, in comparison to crystalline-based inorganic LEDs, OLEDs suffer reduced brightness, shorter lifetimes, and require expensive encapsulation for device operation. To improve the performance of OLEDs, in the late 1990's OLED devices containing mixed emitters of organics and quantum dots were introduced (Mattoussi et al., Journal of Applied Physics 83, 7965 (1998)). Quantum dots are light-emitting nano-sized semiconductor crystals. Adding quantum dots to the emitter layers could enhance the color gamut of the device; red, green, and blue emission could be obtained by simply varying the quantum dot particle size; and the manufacturing cost could be reduced. Because of problems such as aggregation of the quantum dots in the emitter layer, the efficiency of these devices was rather low in comparison with typical OLED devices. The efficiency was even poorer when a neat film of quantum dots was used as the emitter layer (Hikmet et al., Journal of Applied Physics 93, 3509 (2003)). The poor efficiency was attributed to the insulating nature of the quantum dot layer. Later the efficiency was boosted (to ˜1.5 cd/A) upon depositing a mono-layer film of quantum dots between organic hole and electron transport layers (Coe et al., Nature 420, 800 (2002)). It was stated that luminescence from the quantum dots occurred mainly as a result of Forster energy transfer from excitons on the organic molecules (electron-hole recombination occurs on the organic molecules). Regardless of any future improvements in efficiency, these hybrid devices still suffer from all of the drawbacks associated with pure OLED devices. Recently, a mainly all-inorganic LED was constructed (Mueller et al., Nano Letters 5, 1039 (2005)) by sandwiching a monolayer thick core/shell CdSe/ZnS quantum dot layer between vacuum deposited inorganic n- and p-GaN layers. The resulting device had a poor external quantum efficiency of 0.001 to 0.01%. Part of that problem could be associated with the organic ligands of trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP) that were reported to be present post growth. These organic ligands are insulators and would result in poor electron and hole injection onto the quantum dots. In addition, the remainder of the structure is costly to manufacture, due to the usage of electron and hole semiconducting layers grown by high-vacuum techniques, and the usage of sapphire substrates. As described in co-pending, commonly assigned U.S. Ser. No. 11/226,622 by Kahen, which is hereby incorporated by reference in its entirety, additional conducting particles may be provided with the quantum dots in a layer to enhance the conductivity of the light-emitting layer. Quantum dot light-emitting diode structures may be employed to form flat-panel displays. Likewise, colored-light or white-light lighting applications are of interest. Different materials may be employed to emit different colors and the materials may be patterned over a surface to form full-color pixels. In various embodiments, the quantum dot LEDs may be electronically or photonically stimulated and may be mixed or blended with a light-emitting organic host material and located between two electrodes. Referring to FIG. 13 , a prior-art structure employing electronic stimulation uses a substrate 10 on which is formed a first electrode 12 , a light-emissive layer 33 of quantum dots 18 dispersed in an organic light-emitting medium 31 , and a second electrode 16 . Upon the application of a current from the electrodes, electrons and holes injected into the matrix create excitors that are transferred to the quantum dots for recombination, thereby stimulating the quantum dots to produce light. Such a design is described in WO 2005/055330, by Hikmet et al., published Jun. 16, 2005. P-type and/or an n-type organic transport, charge injection, and/or charge blocking layers 22 and 24 respectively may be optionally employed to improve the efficiency of the device. Typically, one electrode will be reflective (e.g. second electrode 16 ) while the other may be transparent (e.g. first electrode 12 ). No particular order is assumed for electrodes 12 and 16 , although they are referenced throughout in this document as first and second, respectively. While quantum dots may be useful and stable light emitters, in prior-art designs the emitted light may be trapped within the light-emitting structure employed to provide current or photo-stimulation to the quantum dots. Due to the high optical indices of the materials used, most of the photons generated by the recombination process are actually trapped in the devices due to total internal reflection. These trapped photons never leave the devices and make no contribution to the light output from these devices. Because light is emitted in all directions from the light-emitting layer, some of the light is emitted directly from the device, and some is emitted into the device and is either reflected back out or is absorbed, and some of the light is emitted laterally and trapped and absorbed by the various layers comprising the device. In general, up to 80% of the light may be lost in this manner. In the prior-art example of FIG. 13 , electrode 12 is transparent and may be typically formed from metal oxides such as indium tin oxide (ITO) having an optical index of 1.8-2.0. Light-emitting organic materials 31 have optical indices of approximately 1.7. P-type and/or n-type organic transport layers 22 and 24 , respectively, optionally employed to improve charge injection, typically have optical indices of approximately 1.65-1.7 for organic materials; inorganic materials typically have indices greater than or equal to 2.0. Substrates on which light-emitting devices are formed typically comprise glass or plastic, having an optical index of approximately 1.5. Light emitted in a high-index layer will be trapped due to total internal reflection when the light encounters a low-index layer. Referring to FIG. 14 , a prior-art light-emitting device has a transparent substrate 10 with a relatively low optical index, a first transparent electrode 12 having a relatively higher optical index, a light-emitting layer 33 having a relatively higher optical index, and a reflective second electrode 16 . Some light emitted from the light-emitting layer 33 will be emitted directly out of the device, through the substrate 10 , as illustrated with light ray 1 . Other light may also be emitted and internally guided in the substrate 10 and light-emitting layers 33 , as illustrated with light ray 2 . Alternatively, some light may be emitted and internally guided in the light-emitting layer 33 and the first transparent electrode 12 , as illustrated with light ray 3 . If the light-emitting layer 33 has an optical index higher than the optical index of the transparent electrode 12 , light may also be trapped in the light-emitting layer 33 alone (see, e.g., light ray 4 ). Light rays 5 emitted toward the reflective second electrode 16 are reflected by the reflective second electrode 16 toward the substrate 10 and then follow one of several light ray paths 1 , 2 , 3 , or 4 . Similar light trapping occurs with relatively high-index optional charge-injection or charge-transport layers (not shown in FIG. 14 ). There is a need therefore for an improved inorganic light-emitting diode device structure that improves the efficiency of the light-emissive display device by releasing more of the heretofore trapped light in the display device.
|
<SOH> SUMMARY OF THE INVENTION <EOH>In accordance with one embodiment, the invention is directed towards a light-emissive device that includes a substrate with a first electrode formed on the substrate. A colloidal light-emitting layer comprising inorganic, light-emissive particles is formed over the first electrode. A second electrode is formed over the light-emitting layer. At least one of the first and second electrodes is transparent. The transparent electrode preferably has a refractive index substantially equal to or greater than the refractive index of the colloidal light-emitting layer. Finally, a light-scattering layer is formed on a side of the transparent electrode opposite the colloidal light-emitting layer. Another aspect of the present invention provides a method for making a light-emissive device, including the steps of: a. providing a substrate; b. forming a first electrode on the substrate; c. forming a dispersion comprising inorganic light emissive particles d. coating the dispersion over the first electrode to form a light-emitting layer comprising a colloid of inorganic, light-emissive particles; e. forming a second electrode over the light-emitting layer; wherein at least one of the first and second electrodes is transparent and wherein the transparent electrode has a refractive index substantially equal to or greater than the refractive index of the colloidal light-emitting layer; and f. forming a light-scattering layer on a side of the transparent electrode opposite the colloidal light-emitting layer.
|
FIELD OF THE INVENTION The present invention relates to inorganic LED display devices including color change materials and quantum dots, and more particularly, to device structures for improving the optical efficiency of such display devices. BACKGROUND OF THE INVENTION Semiconductor light emitting diode (LED) devices, which are primarily inorganic, have been made since the early 1960's and currently are manufactured for usage in a wide range of consumer and commercial applications. The layers comprising the LEDs are based on crystalline semiconductor materials. These crystalline-based inorganic LEDs have the advantages of high brightness, long lifetimes, and good environmental stability. The crystalline semiconductor layers that provide these advantages also have a number of disadvantages. The dominant ones have high manufacturing costs; difficulty in combining multi-color output from the same chip; efficiency of light output; and the need for high-cost rigid substrates. In the mid 1980's, organic light-emitting diodes (OLEDs) were invented (Tang et al, Applied Physics Letter 51, 913 (1987)) based on the usage of small molecular weight molecules. In the early 1990's, polymeric LEDs were invented (Burroughs et al., Nature 347, 539 (1990)). In the ensuing 15 years organic-based LED displays have been brought out into the marketplace and there has been great improvements in device lifetime, efficiency, and brightness. For example, devices containing phosphorescent emitters have external quantum efficiencies as high as 19%; whereas, device lifetimes are routinely reported at many tens of thousands of hours. However, in comparison to crystalline-based inorganic LEDs, OLEDs suffer reduced brightness, shorter lifetimes, and require expensive encapsulation for device operation. To improve the performance of OLEDs, in the late 1990's OLED devices containing mixed emitters of organics and quantum dots were introduced (Mattoussi et al., Journal of Applied Physics 83, 7965 (1998)). Quantum dots are light-emitting nano-sized semiconductor crystals. Adding quantum dots to the emitter layers could enhance the color gamut of the device; red, green, and blue emission could be obtained by simply varying the quantum dot particle size; and the manufacturing cost could be reduced. Because of problems such as aggregation of the quantum dots in the emitter layer, the efficiency of these devices was rather low in comparison with typical OLED devices. The efficiency was even poorer when a neat film of quantum dots was used as the emitter layer (Hikmet et al., Journal of Applied Physics 93, 3509 (2003)). The poor efficiency was attributed to the insulating nature of the quantum dot layer. Later the efficiency was boosted (to ˜1.5 cd/A) upon depositing a mono-layer film of quantum dots between organic hole and electron transport layers (Coe et al., Nature 420, 800 (2002)). It was stated that luminescence from the quantum dots occurred mainly as a result of Forster energy transfer from excitons on the organic molecules (electron-hole recombination occurs on the organic molecules). Regardless of any future improvements in efficiency, these hybrid devices still suffer from all of the drawbacks associated with pure OLED devices. Recently, a mainly all-inorganic LED was constructed (Mueller et al., Nano Letters 5, 1039 (2005)) by sandwiching a monolayer thick core/shell CdSe/ZnS quantum dot layer between vacuum deposited inorganic n- and p-GaN layers. The resulting device had a poor external quantum efficiency of 0.001 to 0.01%. Part of that problem could be associated with the organic ligands of trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP) that were reported to be present post growth. These organic ligands are insulators and would result in poor electron and hole injection onto the quantum dots. In addition, the remainder of the structure is costly to manufacture, due to the usage of electron and hole semiconducting layers grown by high-vacuum techniques, and the usage of sapphire substrates. As described in co-pending, commonly assigned U.S. Ser. No. 11/226,622 by Kahen, which is hereby incorporated by reference in its entirety, additional conducting particles may be provided with the quantum dots in a layer to enhance the conductivity of the light-emitting layer. Quantum dot light-emitting diode structures may be employed to form flat-panel displays. Likewise, colored-light or white-light lighting applications are of interest. Different materials may be employed to emit different colors and the materials may be patterned over a surface to form full-color pixels. In various embodiments, the quantum dot LEDs may be electronically or photonically stimulated and may be mixed or blended with a light-emitting organic host material and located between two electrodes. Referring to FIG. 13, a prior-art structure employing electronic stimulation uses a substrate 10 on which is formed a first electrode 12, a light-emissive layer 33 of quantum dots 18 dispersed in an organic light-emitting medium 31, and a second electrode 16. Upon the application of a current from the electrodes, electrons and holes injected into the matrix create excitors that are transferred to the quantum dots for recombination, thereby stimulating the quantum dots to produce light. Such a design is described in WO 2005/055330, by Hikmet et al., published Jun. 16, 2005. P-type and/or an n-type organic transport, charge injection, and/or charge blocking layers 22 and 24 respectively may be optionally employed to improve the efficiency of the device. Typically, one electrode will be reflective (e.g. second electrode 16) while the other may be transparent (e.g. first electrode 12). No particular order is assumed for electrodes 12 and 16, although they are referenced throughout in this document as first and second, respectively. While quantum dots may be useful and stable light emitters, in prior-art designs the emitted light may be trapped within the light-emitting structure employed to provide current or photo-stimulation to the quantum dots. Due to the high optical indices of the materials used, most of the photons generated by the recombination process are actually trapped in the devices due to total internal reflection. These trapped photons never leave the devices and make no contribution to the light output from these devices. Because light is emitted in all directions from the light-emitting layer, some of the light is emitted directly from the device, and some is emitted into the device and is either reflected back out or is absorbed, and some of the light is emitted laterally and trapped and absorbed by the various layers comprising the device. In general, up to 80% of the light may be lost in this manner. In the prior-art example of FIG. 13, electrode 12 is transparent and may be typically formed from metal oxides such as indium tin oxide (ITO) having an optical index of 1.8-2.0. Light-emitting organic materials 31 have optical indices of approximately 1.7. P-type and/or n-type organic transport layers 22 and 24, respectively, optionally employed to improve charge injection, typically have optical indices of approximately 1.65-1.7 for organic materials; inorganic materials typically have indices greater than or equal to 2.0. Substrates on which light-emitting devices are formed typically comprise glass or plastic, having an optical index of approximately 1.5. Light emitted in a high-index layer will be trapped due to total internal reflection when the light encounters a low-index layer. Referring to FIG. 14, a prior-art light-emitting device has a transparent substrate 10 with a relatively low optical index, a first transparent electrode 12 having a relatively higher optical index, a light-emitting layer 33 having a relatively higher optical index, and a reflective second electrode 16. Some light emitted from the light-emitting layer 33 will be emitted directly out of the device, through the substrate 10, as illustrated with light ray 1. Other light may also be emitted and internally guided in the substrate 10 and light-emitting layers 33, as illustrated with light ray 2. Alternatively, some light may be emitted and internally guided in the light-emitting layer 33 and the first transparent electrode 12, as illustrated with light ray 3. If the light-emitting layer 33 has an optical index higher than the optical index of the transparent electrode 12, light may also be trapped in the light-emitting layer 33 alone (see, e.g., light ray 4). Light rays 5 emitted toward the reflective second electrode 16 are reflected by the reflective second electrode 16 toward the substrate 10 and then follow one of several light ray paths 1, 2, 3, or 4. Similar light trapping occurs with relatively high-index optional charge-injection or charge-transport layers (not shown in FIG. 14). There is a need therefore for an improved inorganic light-emitting diode device structure that improves the efficiency of the light-emissive display device by releasing more of the heretofore trapped light in the display device. SUMMARY OF THE INVENTION In accordance with one embodiment, the invention is directed towards a light-emissive device that includes a substrate with a first electrode formed on the substrate. A colloidal light-emitting layer comprising inorganic, light-emissive particles is formed over the first electrode. A second electrode is formed over the light-emitting layer. At least one of the first and second electrodes is transparent. The transparent electrode preferably has a refractive index substantially equal to or greater than the refractive index of the colloidal light-emitting layer. Finally, a light-scattering layer is formed on a side of the transparent electrode opposite the colloidal light-emitting layer. Another aspect of the present invention provides a method for making a light-emissive device, including the steps of: a. providing a substrate; b. forming a first electrode on the substrate; c. forming a dispersion comprising inorganic light emissive particles d. coating the dispersion over the first electrode to form a light-emitting layer comprising a colloid of inorganic, light-emissive particles; e. forming a second electrode over the light-emitting layer; wherein at least one of the first and second electrodes is transparent and wherein the transparent electrode has a refractive index substantially equal to or greater than the refractive index of the colloidal light-emitting layer; and f. forming a light-scattering layer on a side of the transparent electrode opposite the colloidal light-emitting layer. Advantages The present invention has the advantage that it improves the light output of a light-emissive display device employing a light-emissive layer comprising inorganic light-emitting particles. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross section of a light-emissive device according to one embodiment of the present invention; FIG. 2 is a cross section of a light-emissive device according to another embodiment of the present invention; FIG. 3 is a cross section of a light-emissive device according to an alternative embodiment of the present invention; FIG. 4 is a cross section of a light-emissive device having a thin cover and light-scattering particles according to yet another embodiment of the present invention; FIG. 5 is a cross section of a light-emissive device having a light-scattering layer according to an alternative embodiment of the present invention; FIG. 6 is a cross section of a top-emitting, light-emissive device having a cover according to an alternative embodiment of the present invention; FIG. 7 is a cross section of a bottom-emitting, light-emissive device with conductive and reflective layers according to an alternative embodiment of the present invention; FIG. 8 is a perspective of an optical cavity forming a low-index layer according to an alternative embodiment of the present invention; FIG. 9 is a cross section of a light-emissive device having a thin cover according to an alternative embodiment of the present invention; FIGS. 10A and 10B are cross sections of a light-scattering layer having a binder according to various embodiment of the present invention; FIG. 11 is a cross section of a light-emitting particle according to an embodiment of the present invention; FIG. 12 is a cross section of an agglomeration of colloidal light-emitting and conducting particles according to an embodiment of the present invention; FIG. 13 is a cross section of a prior-art light-emissive device; and FIG. 14 is a cross section of a prior-art light-emissive device illustrating light trapping. It will be understood that the figures are not to scale since the individual layers are too thin and the thickness differences of various layers too great to permit depiction to scale. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, one embodiment of a light-emissive device according to the present invention includes a substrate 10, a first electrode 12 formed on the substrate 10, a colloidal light-emitting layer 14 comprising inorganic, quantum dots 18 formed over the first electrode 12, and a second electrode 16 formed over the colloidal light-emitting layer 14. At least one of the first or second electrodes 12, 16 is transparent. In this embodiment, the first electrode 12 is reflective, while second electrode 16 is transparent and has a refractive index substantially equal to or greater than the refractive index of the colloidal light-emitting layer 14. A light-scattering layer 28 is formed on a side of the transparent electrode 16 opposite the colloidal light-emitting layer 14. The light-scattering layer typically includes transparent particles 26, for example, titanium dioxide such as is known in the art and commercially available. Such light-scattering particles 26 typically have a refractive index of 2.0 or greater. As defined herein, with respect to optical index values substantially equal to means with plus or minus 0.1. In various further embodiments of the present invention, the light-emissive device may further comprise one or more optional charge-injection, -transport, and/or -blocking layers 22, 24 formed between the colloidal light-emitting layer 14 and either of the electrodes 12, 16. In a further embodiment of the present invention, the electrodes 12, 16 and any optional charge-injection, -transport, and/or -blocking layers 22, 24 formed between the colloidal light-emitting layer 14 and either of the electrodes 12, 16, have a refractive index greater than the refractive index of the substrate 10. According to further embodiments of the present invention, any optional charge-injection, -transport, and/or -blocking layers 22, 24 may have a refractive index substantially greater than or equal to the refractive index of the colloidal light-emitting layer 14 and/or substantially equal to or less than the refractive index of the transparent electrode 16. In various embodiments of the present invention, electrically conductive transparent layers and/or electrodes may be formed from metal oxides or metal alloys having an optical index of 1.8 or more. For example, organic devices typically employ sputtered indium tin oxide whose optical index may be in the range of 1.8 to 2.0. As taught in the prior art, such a metal oxide with such an optical index will cause a greater amount of light trapping, thereby, reducing the light efficiency of such prior art devices. According to various embodiments of the present invention, a transparent electrode, for example tin oxide, has an optical index greater or equal to optical index of the colloidal light-emissive layer. Hence, a transparent electrode with a greater optical index is preferred and may be formed by additional annealing steps, deposition at higher temperatures, or by employing materials having a greater optical index, as is known in the art. In an inorganic embodiment of the present invention, p-type and/or an n-type charge-injection, -transport, or -blocking layers 22 and 24, respectively, optionally employed to provide charge control, are typically formed from metal alloys and have optical indices of approximately greater than 1.8, while organic materials typically have optical indices of approximately 1.7. Substrates on which light-emitting devices are formed typically comprise glass or plastic, having an optical index of approximately 1.5. Hence, it will generally be the case that the electrodes 12, 16 and any charge-injection, -transport, and/or -blocking layers 22, 24 formed between the colloidal light-emitting layer 14 and either of the electrodes 12, 16, will have a refractive index greater than the refractive index of the substrate 10. Useful material for electrodes includes ITO, CdSe, ZnTe, SnO2, and AlZnO. These materials have typical refractive indices in the range of 1.8 to 2.7. Useful inorganic materials for charge-control layers include CdZnSe and ZnSeTe. In another embodiment of the present invention, the transparent electrode has an optical index greater than or equal to the optical index of the charge-control layers. Organic materials are also known in the art. Reflective electrodes may comprise evaporated or sputtered metals or metal alloys, including Al, Ag, and Mg and alloys thereof. Deposition processes for these materials are known in the art and include sputtering and evaporation. Some materials may also be deposited using ALD or CVD processes, as are known in the art. However, organic materials are more environmentally sensitive and may have limited lifetimes compared to inorganic materials. Referring to FIG. 2, in a bottom-emitter embodiment of the present invention, the substrate 10 and the first electrode 12 are transparent while the second electrode 16 may be reflective so that light may be emitted through the substrate 10. Alternatively, referring back to FIG. 1, in a top-emitter embodiment of the present invention, the substrate 10 may be opaque, the first electrode 12 is reflective, and the second electrode 16 is transparent, so that light is emitted through the second electrode 16 and a transparent cover 20 (FIG. 6, 9) over the second electrode 16. The light-scattering layer 28 may be variously located, for example, adjacent to the second electrode 16 (in a top-emitter configuration and where second electrode 16 is transparent, as shown in FIG. 1). Alternatively, as shown in FIG. 2, the light-scattering layer 28 may be located adjacent to first electrode 12 (in a bottom-emitter configuration and where first electrode 12 is transparent, as shown in FIG. 2). As employed herein, a light-scattering layer 28 is an optical layer that tends to randomly redirect any light that impinges on the layer from any direction. As used herein, a transparent electrode is one that passes some light and includes electrodes that are semi-transparent, partially reflective, or partially absorptive. In various embodiments of the present invention, the light-scattering layer 28 may be adjacent to either electrode opposite the colloidal light-emitting layer 14. Light-scattering layer 28 may comprise a volume scattering layer or a surface scattering layer. In certain embodiments, e.g., light-scattering layer 28 may comprise materials having at least two different refractive indices. The light-scattering layer 28 may comprise, e.g., a matrix of lower refractive index and scattering particles 26 having a higher refractive index. Alternatively, the matrix may have a higher refractive index and the scattering particles 26 may have a lower refractive index. For example, the matrix may comprise silicon dioxide or cross-linked resin having indices of approximately 1.5, or silicon nitride with a much higher index of refraction. If light-scattering layer 28 has a thickness greater than one-tenth part of the wavelength of the emitted light, then it is desirable for the index of refraction of at least one material in the light-scattering layer 28 to be approximately equal to or greater than the transparent electrode to which it is adjacent. This is to insure that all of the light trapped in the colloidal light-emitting layer 14 and transparent electrode can experience the direction altering effects of scattering layer 28. If light-scattering layer 28 has a thickness less than one-tenth part of the wavelength of the emitted light, then the materials in the scattering layer need not have such a preference for their refractive indices. In an alternative embodiment, light-scattering layer 28 may comprise particles 26 deposited on another layer, e.g., particles of titanium dioxide may be coated over the transparent electrode to scatter light. Preferably, such particles are at least 100 nm in diameter to optimize the scattering of visible light. Alternatively, light-scattering layer 28 may comprise a rough, diffusely reflecting or refracting surface of an electrode. Scattering particles 26 may be deposited by a variety of methods known in the art, for example, spraying, spinning, or inkjet deposition. In operation, a current is provided through the electrodes 12 and 16 by electrical control devices (not shown), such as, device drivers and thin-film transistors, thereby causing the excitation of the light-emitting particles 18 and the emission of light. Because the various layers 12, 16, 22, 24 in the device may have a higher refractive index than the substrate 10, emitted light may be trapped in these layers by total internal reflection. Hence, light emitted at a small angle to the substrate 10 normal will be emitted from the device. However, light emitted at a large angle to the substrate 10 normal will be trapped due to total internal reflection at the interface with the relatively lower index substrate 10. Such trapped light is eventually absorbed and contributes to a loss of device efficiency. According to an embodiment of the present invention, the light-scattering particles 26 serve to scatter trapped light out of the device. When trapped light interacts with the light-scattering particles 26, the light may be redirected into an angle at which the light will not experience total internal reflection, therefore increasing the light-emission efficiency of the device. While some light may be scattered into an angle that does experience total internal reflection, the light will eventually re-encounter a light-scattering particle 26 that will redirect the light out of the device, unless it is first absorbed. In other alternative embodiments of the present invention, the first or second electrode 12, 16 may comprise a transparent conductive layer and a reflective layer. Referring to FIG. 3, second electrode 16 comprises a transparent conductive layer 16a and a reflective layer 16b. The reflective layer 16b may be conductive and comprise, for example, metal. In particular, since transparent conductors suffer from reduced conductivity as compared to metals, the reflective layer 16b may have a higher conductivity than the transparent conductive layer 16a. Since the light-emissive particles 18 are stimulated by electrical current, the conductivity of the electrodes is important. The transparent conductive layer 16a is divided into two portions; a first portion 25 over which the scattering layer 28 is formed and a second portion 27 wherein the transparent conductive layer 16a is in electrical contact with the reflective layer 16b. This arrangement enables a highly conductive reflective electrode 16 while locating the light-scattering layer 26 above the layers 12, 14, 22, 24. Since light-scattering layers 28 are typically very rough and may lead to electrical shorts between the electrodes 12, 16, such a location for the light-scattering layer 28 may aid in construction of the device and improve yields. Light-scattering layer 28 may be deposited using spin coating, spray coating, or using inkjet deposition, as has been demonstrated by applicant. In particular, the configuration of FIG. 3 may be constructed by first sputtering a transparent, conductive layer 16a, inkjet depositing the scattering layer 26 in only the first locations 25, and then evaporating or sputtering a metal reflective layer 16b over both the light-scattering layer 26 and the transparent, conductive layer 16a to form the reflective layer 16b. Referring to FIGS. 4 and 6, the light-scattering layer 28 may also be located between a conductive transparent layer 12a and a reflective layer 12b. The electrode 12 (or transparent, conductive layer 12a) may be patterned and electrically connected to thin-film electrical components (not shown) comprising an active- or passive-matrix circuit for driving the device. The second electrode 16 (or, if present, transparent conductive layer 16a and reflective layer 16b) may be continuous and unpatterned. Referring to FIG. 5, a protective layer 17 may be formed between the transparent, conductive layer 16a (or the electrode 16, particularly if the second electrode 16 is transparent) and the light-scattering layer 28 to protect the layers 12, 14, 22, 24, and 16 (or 16a). Such a protective layer 17 may also be conductive. Useful layers include metal oxides deposited by, for example, by atomic layer deposition (ALD) or chemical vapor deposition (CVD) processes, which are known in the art. If the protective layer 17 is electrically conductive, it may continuously cover the transparent electrode 16 or transparent conductive layer 16a; if the protective layer 17 is not conductive or insufficiently conductive, it may be patterned within the areas 25. In a further embodiment of the present invention, a cover may be provided over the colloidal light-emitting layer 14 and electrodes 12, 16 to protect the device. Referring to FIGS. 4, 9 the cover 20 may be coated directly on the second electrode 16, scattering layer 28 or other layers formed over the second electrode 16 (such as a protective layer 17). Alternatively, referring to FIG. 6, the cover 20 may be a second substrate affixed to the substrate 10 with a gap 19 formed between the second electrode 16 (or protective layer 17 or scattering layer 28) and the cover 20. In further embodiments of the present invention, a low-index layer 36 may be provided to prevent light propagation in a relatively thick cover or substrate (much thicker than the layer 12, 14, 16, 22, 24) to maintain the sharpness of a pixilated device. The low-index layer 36 may comprise a solid layer, a void (for example, a vacuum), or a cavity. The cavity may be filled with a gas, for example, air or an inert gas such as nitrogen, argon or helium. Alternatively, a solid material, for example, a low-index polymer, may be employed, but such solid material must have an optical index lower than that of the light-emitting layers 14. Preferably, the low-index layer 36 is at least one micron thick, and more preferably at least two microns thick. Referring to FIG. 6, in a further top-emitter embodiment of the present invention, the low-index layer 36 may be the gap 19 provided between the cover 20 and the light-scattering layer 28. The low-index layer 36 has a refractive index lower than the cover 20 refractive index. In such an embodiment, light emitted by the colloidal light-emitting layer 14 will be emitted into the transparent electrode 16 and any optional charge-management layers. Light 66 emitted at a small angle to the substrate 10 normal will emit from the device. However, light 68 emitted at a large angle to the substrate 10 normal will normally be trapped due to total internal reflection at the interface with the relatively lower index substrate 10 or cover 20. According to an embodiment of the present invention, some light will instead be trapped at the interface with the low-index layer 36. The trapped light will subsequently be scattered by the scattering particles 26 into a different angle and will either be emitted or trapped again until the light re-encounters the scattering particles 26 and is emitted from the device or absorbed. The low-index layer 36 ensures that light, once transmitted into the low-index layer 36, will not be trapped in the substrate 10 or cover 20. Since the other layers are relatively thin, trapped light will travel only a short distance before being scattered out of the device, thereby, maintaining the sharpness of the device. Referring to FIGS. 10A and 10B, according to other top-emitter embodiments of the present invention, the low-index layer 36 may be a vacuum or the layer may be filled with a relatively low-refractive index gas and the light-scattering layer 28 comprises a plurality of relatively high-refractive index light-scattering transparent particles 26 projecting into the layer 36 without contacting the cover 20 and further comprising an adhesive binder 40 in contact with at least some of the light-scattering particles 26 to adhere the light-scattering particles 26 to the transparent electrode 16 or protection layer 17. As shown in FIGS. 10A and 10B, adhesive binder 40 adheres the light-scattering particles 26 to the transparent electrode 16 or protective layer 17. As shown in FIG. 10A, a minimal amount of adhesive binder 40 is employed to adhere the light-scattering particles 26 to the underlying layer. As shown in FIG. 10B, a greater quantity of adhesive binder 40 is employed to adhere the light-scattering particles 26 to the underlying layer such that some of the light-scattering particles 26 are completely immersed in the adhesive binder 40. In one embodiment of the present invention, however, at least a fraction of, and preferably most of, the light-scattering particles 26 project into the low-index layer 36 without contacting the cover 20. Referring to FIG. 7, in a further bottom-emitter embodiment of the present invention, a low-index layer 36 may be provided between the substrate 10 and the light-scattering layer 28. The low-index layer 36 has a refractive index lower than the substrate 10 refractive index. In such an embodiment, light emitted by the colloidal light-emitting layer 14 will be emitted into the first electrode 12 and any optional charge-management layers. Light 66 emitted at a small angle to the substrate 10 normal will be emitted from the device. However, light 68 emitted at a large angle to the substrate 10 normal will normally be trapped due to total internal reflection at the interface with the relatively lower index substrate 10. According to an embodiment of the present invention, some light will instead be trapped at the interface with the low-index layer 36. The trapped light will subsequently be scattered by the scattering particles 26 into a different angle and will either be emitted or trapped again, until the light re-encounters the scattering particles 26 and is emitted from the device or absorbed. The low-index layer 36 ensures that light, once transmitted into the low-index layer 36, will not be trapped in the substrate 10. Since the other layers are relatively thin compared to the substrate 10, trapped light will travel only a short distance before being scattered out of the device, thereby maintaining the sharpness of the device. FIG. 7 also illustrates the use of thin-film electronic components 30 for controlling the application of current to the electrodes 12 and 16. Planarization layers 32 and 34 are used to electrically isolate the electrodes and provide a smooth surface on which subsequent layers may be coated. Referring to FIG. 7 and FIG. 8, in one embodiment of the present invention, the low-index layer 36 is an optical isolation layer formed over the substrate 10, wherein the first electrode 12 (now transparent) or a second layer 38 formed between the optical isolation layer 36 and the transparent electrode 12 comprises one or more openings 41 leading to the optical isolation layer 36, and the optical isolation layer 36 is formed by etching a sacrificial layer deposited between the substrate 10 and the transparent first electrode 12 or the second layer through the one or more openings 41. The planarization layer 32 may serve as the floor of the optical isolation layer 36 and walls 42 employed to support the transparent first electrode 12. The optical isolation layer 36 may be formed by depositing a sacrificial layer (not shown) in the location of optical isolation layer 36 over for example, the insulating and planarizing layer 32. A second layer 38 may then be formed over the sacrificial layer, the second layer 38, having openings 41, exposing portions of the sacrificial layer. An etchant may then be employed to etch the materials of the sacrificial layer away, leaving a cavity beneath the second layer 38 forming the optical isolation layer 36. Further layers, for example the scattering layer 28 or first electrode 12 may be formed over the second layer 38. Alternatively, such layers as the scattering layer 28 or first electrode 12 may be employed as the second layer 38 and no intermediate, covering layer may be necessary to form a layer over the optical isolation layer 36. The second layer 38 may be supported over the cavity comprising the optical isolation layer 36 by walls 42 adjacent to the light-emitting areas 25 or by pillars of support material formed in the light-emissive area 25. The walls 42 or pillars may comprise the same materials as the second layer 38 and be formed in a common patterning step. In such an embodiment, the sacrificial layer is formed only in the light-emissive area 25. Materials and etchants known in the photolithographic industry may be employed to form the sacrificial layer and/or second layer 38. In particular, the micro-electromechanical systems (MEMS) art describes useful techniques, as described in commonly assigned U.S. Pat. No. 6,238,581 entitled “Process for manufacturing an electromechanical grating device”. This disclosure describes a method for manufacturing a mechanical grating device comprising the steps of: providing a spacer layer on top of a protective layer which covers a substrate; etching a channel entirely through the spacer layer; depositing a sacrificial layer at least as thick as the spacer layer; rendering the deposited sacrificial layer optically coplanar by chemical mechanical polishing; providing a tensile ribbon layer completely covering the area of the channel; providing a conductive layer patterned in the form of a grating; transferring the conductive layer pattern to the ribbon layer and etching entirely through the ribbon layer; and removing entirely the sacrificial layer from the channel. With respect to the present invention, such a process can be simplified since the requirement for chemical mechanical polishing and the grating structure are unnecessary. Likewise, U.S. Pat. No. 6,307,663 and, in particular, U.S. Pat. No. 6,663,788 describe further devices having cavities and methods for forming cavities useful in the present invention. For example, the sacrificial layer may comprise polysilicon, polyamide, or a silicon oxide. The second layer 38 may comprise a silicon nitride, a silicon oxide, or a metal oxide. The choice of materials will depend greatly on the choice of etchants, for example, XeF2 can etch polysilicon. Suitable cavities may be formed by employing a sacrificial layer of polysilicon formed over a silicon dioxide layer with a second layer of silicon nitride having photolithographically patterned openings exposing portions of the first sacrificial layer and then etching away the polysilicon sacrificial layer using XeF2 gas. In an alternative embodiment, the sacrificial layer may be silicon dioxide covered with indium tin oxide (ITO) and hydrofluoric acid employed to etch out the silicon dioxide sacrificial layer. In such an embodiment, the ITO layer may serve as a transparent electrode, thus combining second layer 38 and first electrode 12 into a common layer that may reduce materials costs, processing steps, and improve optical performance by avoiding light absorption in the second layer 38. Once formed, the cavity may be filled with a gas, left as a vacuum, or the openings employed to fill the cavity with a solid material, for example a low-index polymer. In an alternative process, a low-index material may first be formed and the remainder of the OLED structure formed over the low-index material. Preferably, the low-index material may have a refractive index close to one, for example, an aerogel may be employed. Such an aerogel may be formed, for example, by employing a sol-gel process with MgF to make a coating with a refractive index of 1.15 using nano-particles. Suitable materials and processes are known in the art. In yet another embodiment of the present invention, a plurality of spaced-apart light-emitting elements 25 emitting a common color of light may be formed over the substrate. As shown in FIGS. 3 and 7, the first electrode 12 (transparent for this embodiment) is patterned to form light-emitting areas 25 separated by non-light-emitting areas 27. The colloidal light-emitting layer 14 may be likewise patterned to match the light-emitting areas 25 and the areas 25 provided with different light-emitting materials to form a full-color pixilated display device emitting light of different colors, for example, red, green, blue, or white. The differently colored areas may be, for example, sequentially arranged in stripes so that areas 25 emitting the same color of light are spaced apart and may be separated by emitters of different colors. The distance that trapped light may propagate in a layer may be described as W A = t π - 2 θ C + sin ( 2 θ C ) cos 2 ( θ C ) where WA is the average lateral propagation light at each internal reflection and θC is the critical angle for glass to air. For the specific case of index 1.5, one can now state that of the 55.6% of the light that is reflected back to the scattering layer, that the average lateral propagation is equal to 4.82*t where t is the thickness of the layer. Of that light, 44.4% will refract directly to the air with no additional lateral propagation, and 55.6% will experience lateral propagation of 4.82*t. The second lateral propagation will be at a random angle relative to the first lateral propagation, so the addition will not be linear, but the two will add in quadrature (i.e. square root of the sum of the squares). The following table follows the average lateral propagation and fraction of the light escaping after each total reflection for n=1.5. Fraction Average lateral Fraction Pass # Escaping propagation Returning 1 44.44% 0 t 55.56% 2 24.69% 4.8 t 30.87% 3 13.72% 6.8 t 17.15% 4 7.62% 8.3 t 9.53% 5 3.39% 9.6 t 6.14% These results are now interpreted and applied to various embodiments of the present invention. Had there been no scattering layer, only about 20% to 30% of the generated light would have escaped, and the average lateral propagation would be zero. The off-axis rays would propagate laterally while traversing the glass substrate, but the viewer's eye is located at a unique angular value of θ and all the rays emerging at that angle have exactly the same lateral propagation, so the eye re-creates a precise image. That is why the lateral propagation of light traversing the glass on the first pass can be ignored. The image degradation results from the random direction change which occurs when the light reflects back to the scattering layer. From the table one sees that for this non-absorbing model, 100% of the light generated eventually escapes, but 5 to 10 reflections within the glass are required. The lateral propagation is proportional to the thickness of the glass, t. Reducing t to the size of the pixel pitch reduces the lateral propagation proportionately. More than half of the escaping light will experience a lateral propagation of nearly 5t, and 10% of the light will propagate laterally by more than 10t. An exact curve of lateral propagation probability versus lateral propagation distance could be calculated using the sophisticated model alluded to above. If a human viewer is sensitive to degradation wherein 50% of the light scatters by twice the pixel pitch, then one would desire that the layer have a thickness t which is less than half of the pixel pitch. For a real medium with absorption, the amount of light escaping is reduced, and the amount of image degradation is reduced. Furthermore, most scattering layers are not fully Lambertian and suffer from reduced scattering at high angles. This further reduces the magnitude of image degradation. An advantageous range for real devices would be a t value equal to the pixel pitch, that is the thickness of the cover 20 or substrate 10 is the maximum distance between corresponding points in neighboring pixels emitting the same color of light. An acceptable range of t is less than or equal to twice the pixel pitch, that is the thickness of at least one of the substrate 10 or cover 20 through which light is emitted is less than or equal to two times the pixel pitch. Hence, in such an application (FIGS. 3, 4), it may be desirable to limit the thickness of the substrate 10 or cover 20, for example, to twice the distance t between the light-emitting elements emitting the same color of light to enhance the sharpness of the display. Through experiment, applicants have discovered that, for optimal efficiency, the light-scattering layer 28 should have a thickness of between 300 nm and 3 microns. Moreover, the light-scattering layer 28 may comprise light-scattering particles 26 wherein the average ratio of the volume of light-scattering particles 26 to the volume of the layer is greater than 0.55. In one structure according to an embodiment of the present invention, the light-emissive particles 18 are formed in a thin layer, for example a mono-layer. Such a mono-layer may improve the transfer of energy into the light-emissive particles 18. By providing charge-control layers 22, 24 or a transparent conducting layer 16a, the light-emissive particles 18 may be located at a distance from any metal layers (e.g. a reflective electrode) to ensure, for example, that interactions between a reflective, metal layer and the light-emitting particles 18 causing surface plasmon effects do not occur, thereby improving the efficiency of the device. For example, the thickness of charge-control layers 22, 24 or a transparent conducting layer 12a or 16a may be the greater than or equal to the thickness of the wavelength of the light emitted by the particles 18, or at least, for example, 500 nm. According to various embodiments of the present invention, the layers 12, 14, 16, 22, 24 may be formed by coating over the substrate 10. Alternatively, the substrate 10 may be considered to be a layer coated over the layers 12, 14, 16, 22, 24, as illustrated in FIG. 4. Referring to FIGS. 4, 6, 7, and 9, a device of the present invention may comprise two substrates 20 and 10, on one of which the layers are formed. However, with respect to the relative locations of the various layers and the structure of the present invention, either of the two substrates 10 and 20 may be considered to be the substrate, upon which the multilayered structure is built. The scattering layer 28 can employ a variety of materials. For example, randomly located spheres of titanium dioxide may be employed in a matrix of polymeric material. Alternatively, a more structured arrangement employing ITO, silicon oxides, or silicon nitrides may be used. In a further embodiment, the refractive materials may be incorporated into the electrode itself so that the electrode is a scattering layer. Shapes of refractive elements may be cylindrical, rectangular, or spherical, but it is understood that the shape is not limited thereto. The difference in refractive indices between materials in the scattering layer 28 may be, for example, from 0.3 to 3, and a large difference is generally desired. The thickness of the scattering layer, or size of features in, or on the surface of, a scattering layer may be, for example, 0.03 to 50 μm. It is generally preferred to avoid diffractive effects in the scattering layer. Such effects may be avoided, for example, by locating features randomly or by ensuring that the sizes or distribution of the refractive elements are not the same as the wavelength of the color of light emitted by the device from the light-emitting area. Materials of the light-scattering layer 28 can include organic materials (for example, polymers or electrically conductive polymers) or inorganic materials. The organic materials may include, e.g., one or more of polythiophene, PEDOT, PET, or PEN. The inorganic materials may include, e.g., one or more of SiOx (x>1), SiNx (x>1), Si3N4, TiO2, MgO, ZnO, Al2O3, SnO2, In2O3, MgF2, and CaF2. The scattering layer 28 may comprise, for example, silicon oxides and silicon nitrides having a refractive index of 1.6 to 1.8 and doped with titanium dioxide having a refractive index of 2.5 to 3. Polymeric materials having refractive indices in the range of 1.4 to 1.6 may be employed having a dispersion of refractive elements of material with a higher refractive index, for example, titanium dioxide. In further embodiments of the present invention and as illustrated in FIG. 11, conductive, non-emissive particles 140 may be located in the colloidal light-emitting layer 14. The particles 140 may have a higher conductivity and may improve transfer of energy into the light-emissive particles 18. Such conductive particles, for example, nano-particles, are known in the art. Agglomerations 130 of light-emissive particles 18 and, optionally, conductive, non-emissive particles 140 may by considered to be within the present invention, as single particles located within the light-emissive layer 14. Referring to FIGS. 11 and 12, for one embodiment of the present invention, the light-emissive particles 18 are quantum dots. Using quantum dots as the emitters in light-emitting diodes confers the advantage that the emission wavelength can be simply tuned by varying the size of the quantum dot particle. As such, spectrally narrow (resulting in a larger color gamut), multi-color emission can occur. If the quantum dots are prepared by colloidal methods [and not grown by high vacuum deposition techniques (S. Nakamura et al., Electronics Letter 34, 2435 (1998))], then the substrate no longer needs to be expensive or lattice matched to the LED semiconductor system. For example, the substrate could be glass, plastic, metal foil, or Si. Forming quantum dot LEDs using these techniques is highly desirably, especially if low cost deposition techniques are used to deposit the LED layers. A schematic of a core/shell quantum dot 120 emitter is shown in FIG. 11. The particle contains a light-emitting core 100, a semiconductor shell 110, and organic ligands 115. Since the size of typical quantum dots is on the order of a few nanometers and commensurate with that of its intrinsic exciton, both the absorption and emission peaks of the particle are blue-shifted relative to bulk values (R. Rossetti et al., Journal of Chemical Physics 79, 1086 (1983)). As a result of the small size of the quantum dots, the surface electronic states of the dots have a large impact on the dot's fluorescence quantum yield. The electronic surface states of the light-emitting core 100 can be passivated either by attaching appropriate (e.g., primary amines) organic ligands 115 to its surface or by epitaxially growing another semiconductor (the semiconductor shell 110) around the light-emitting core 100. The advantages of growing the semiconductor shell 110 (relative to organically passivated cores) are that both the hole and electron core particle surface states can be simultaneously passivated, the resulting quantum yields are typically higher, and the quantum dots are more photostable and chemically robust. Because of the limited thickness of the semiconductor shell 110 (typically 1-2 monolayers), its electronic surface states also need to be passivated. Again, organic ligands 115 are the common choice. Taking the example of a CdSe/ZnS core/shell quantum dot 120, the valence and conduction band offsets at the core/shell interface are such that the resulting potentials act to confine both the holes and electrons to the core region. Since the electrons are typically lighter than the heavy holes, the holes are largely confined to the cores, while the electrons penetrate into the shell and sample its electronic surface states associated with the metal atoms (R. Xie et al., Journal of the American Chemical Society, 127, 7480 (2005)). Accordingly, for the case of CdSe/ZnS core/shell quantum dots 120, only the shell's electron surface states need to be passivated; an example of a suitable organic ligand 115 would be one of the primary amines which forms a donor/acceptor bond to the surface Zn atoms (X. Peng et al., Journal of the American Chemical Society, 119, 7019 (1997)). In summary, typical highly luminescent quantum dots have a core/shell structure (higher bandgap surrounding a lower band gap) and have non-conductive organic ligands 115 attached to the shell's surface. Colloidal dispersions of highly luminescent core/shell quantum dots have been fabricated by many workers over the past decade (O. Masala and R. Seshadri, Annual Review of Materials Research 34, 41 (2004)). The light-emitting core 100 is composed of type IV (Si), III-V (InAs), or II-VI (CdTe) semiconductive material. For emission in the visible part of the spectrum, CdSe is a preferred core material since by varying the diameter (1.9 to 6.7 nm) of the CdSe core; the emission wavelength can be tuned from 465 to 640 nm. As is well-known in the art, visible emitting quantum dots can be fabricated from other material systems, such as, doped ZnS (A. A. Bol et al., Phys. Stat. Sol. B224, 291 (2001)). The light-emitting cores 100 are made by chemical methods well known in the art. Typical synthetic routes are decomposition of molecular precursors at high temperatures in coordinating solvents, solvothermal methods (disclosed by O. Masala and R. Seshadri, Annual Review of Materials Research, 34, 41 (2004)), and arrested precipitation (disclosed by R. Rossetti et al., Journal of Chemical Physics, 80, 4464 (1984)). The semiconductor shell 110 is typically composed of type II-VI semiconductive material, such as, CdS or ZnSe. The shell semiconductor is typically chosen to be nearly lattice matched to the core material and have valence and conduction band levels such that the core holes and electrons are largely confined to the core region of the quantum dot. Preferred shell material for CdSe cores is ZnSexS1-x, with x varying from 0.0 to 0.5. Formation of the semiconductor shell 110 surrounding the light emitting core 100 is typically accomplished via the decomposition of molecular precursors at high temperatures in coordinating solvents (M. A. Hines et al., Journal of Physical Chemistry, 100, 468 (1996)) or reverse micelle techniques (A. R. Kortan et al., Journal of the American Chemical Society, 112, 1327 (1990)). As is well known in the art, two low-cost means for forming quantum dot films is depositing the colloidal dispersion of core/shell quantum dots 120 by drop casting and spin casting. Alternatively, spray deposition may be employed. Common solvents for drop casting quantum dots are a 9:1 mixture of hexane:octane (C. B. Murray et al., Annual Review of Materials Science, 30, 545 (2000)). The organic ligands 115 need to be chosen such that the quantum dot particles are soluble in hexane. As such, organic ligands with hydrocarbon-based tails are good choices, such as, the alkylamines. Using well-known procedures in the art, the ligands coming from the growth procedure (TOPO, for example) can be exchanged for the organic ligand 115 of choice (C. B. Murray et al., Annual Review of Materials Science, 30, 545 (2000)). When depositing a colloidal dispersion of quantum dots, the requirements of the solvent are that it easily spreads on the deposition surface and the solvents evaporate at a moderate rate during the deposition process. It was found that alcohol-based solvents are a good choice; for example, combining a low boiling point alcohol, such as, ethanol, with higher boiling point alcohols, such as, a butanol-hexanol mixture, results in good film formation. Correspondingly, ligand exchange can be used to attach an organic ligand (to the quantum dots) whose tail is soluble in polar solvents; pyridine is an example of a suitable ligand. The quantum dot films resulting from these two deposition processes are luminescent, but non-conductive. The films are resistive since non-conductive organic ligands separate the core/shell quantum dot 120 particles. The films are also resistive since as mobile charges propagate along the quantum dots, the mobile charges get trapped in the core regions due to the confining potential barrier of the semiconductor shell 110. Proper operation of inorganic LEDs typically requires low resistivity n-type and p-type transport layers, surrounding a conductive (nominally doped) and luminescent emitter layer. As discussed above, typical quantum dot films are luminescent, but insulating. FIG. 13 schematically illustrates a way of providing an inorganic light-emitting layer 14 that is simultaneously luminescent and conductive. The concept is based on co-depositing small (<2 nm), conductive inorganic nanoparticles 140 along with the core/shell quantum dots 120 to form the inorganic colloidal light-emitting layer 14. A subsequent inert gas (Ar or N2) anneal step is used to sinter the smaller inorganic nanoparticles 140 amongst themselves and onto the surface of the larger core/shell quantum dots 120. Sintering the inorganic nanoparticles 140, results in the creation of a conductive semiconductor agglomeration 130 useful in layer 14 or forming a matrix in layer 14. Through the sintering process, this agglomeration 130 is also connected to the core/shell quantum dots 120. As such, a conductive path is created from the edges of the inorganic colloidal light-emitting layer 14, through the semiconductor agglomeration 130 and to each core/shell quantum dot 120, where electrons and holes recombine in the light emitting cores 100. It should also be noted that encasing the core/shell quantum dots 120 in the conductive semiconductor agglomeration 130 and by layers 22 has the added benefit that it protects the quantum dots environmentally from the effects of both oxygen and moisture. The inorganic nanoparticles 140 need to be composed of conductive semiconductive material, such as, type IV (Si), III-V (GaP), or II-VI (ZnS or ZnSe) semiconductors. In order to easily inject charge into the core/shell quantum dots 120, it is preferred that the inorganic nanoparticles 140 be composed of a semiconductor material with a band gap comparable to that of the semiconductor shell 110 material, more specifically a band gap within 0.2 eV of the shell material's band gap. For the case that ZnS is the outer shell of the core/shell quantum dots 120, then the inorganic nanoparticles 140 are composed of ZnS or ZnSSe with a low Se content. The inorganic nanoparticles 140 are made by chemical methods well known in the art. Typical synthetic routes are decomposition of molecular precursors at high temperatures in coordinating solvents, solvothermal methods (O. Masala and R. Seshadri, Annual Review of Materials Research, 34, 41 (2004)), and arrested precipitation (R. Rossetti et al., Journal of Chemical Physics, 80, 4464 (1984)). As is well known in the art, nanometer-sized nanoparticles melt at a much reduced temperature relative to their bulk counterparts (A. N. Goldstein et al., Science 256, 1425 (1992)). Correspondingly, it is desirable that the inorganic nanoparticles 140 have diameters less than 2 nm in order to enhance the sintering process, with a preferred size of 1-1.5 nm. With respect to the larger core/shell quantum dots 120 with ZnS shells, it has been reported that 2.8 nm ZnS particles are relatively stable for anneal temperatures up to 350° C. (S. B. Qadri et al., Physical Review B60, 9191 (1999)). Combining these two results, the anneal process has a preferred temperature between 250 and 300° C. and a duration up to 60 minutes, which sinters the smaller inorganic nanoparticles 140 amongst themselves and onto the surface of the larger core/shell quantum dots 120, whereas the larger core/shell quantum dots 120 remain relatively stable in shape and size. To form an inorganic colloidal light-emitting layer 14, a co-dispersion of inorganic nanoparticles 140 and core/shell quantum dots 120 may be formed. Since it is desirable that the core/shell quantum dots 120 be surrounded by the inorganic nanoparticles 140 in the inorganic colloidal light-emitting layer 14, the ratio of inorganic nanoparticles 140 to core/shell quantum dots 120 is chosen to be greater than 1:1. A preferred ratio is 2:1 or 3:1. Depending on the deposition process, such as, spin casting or drop casting, an appropriate choice of organic ligands 115 is made. Typically, the same organic ligands 115 are used for both types of particles. In order to enhance the conductivity (and electron-hole injection process) of the inorganic light emitting layer 14, it is preferred that the organic ligands 115 attached to both the core/shell quantum dots 120 and the inorganic nanoparticles 140 evaporate as a result of annealing the inorganic light emitting layer 14 in an inert atmosphere. By choosing the organic ligands 115 to have a low boiling point, they can be made to evaporate from the film during the annealing process (C. B. Murray et al., Annual Review of Material Science 30, 545 (2000)). Consequently, for films formed by drop casting, shorter chained primary amines, such as, hexylamine are preferred; for films formed by spin casting, pyridine is a preferred ligand. Annealing thin films at elevated temperatures can result in cracking of the films due to thermal expansion mismatches between the film and the substrate. To avoid this problem, it is preferred that the anneal temperature be ramped from 25° C. to the anneal temperature and from the anneal temperature back down to room temperature. A preferred ramp time is on the order of 30 minutes. The thickness of the resulting inorganic colloidal light-emitting layer 14 should be between 10 and 100 nm. Following the anneal step, the core/shell quantum dots 120 would be devoid of an outer shell of organic ligands 115. For the case of CdSe/ZnS quantum dots, having no outer ligand shell would result in a loss of free electrons due to trapping by the shell's unpassivated surface states (R. Xie, Journal of American Chemical Society 127, 7480 (2005)). Consequently, the annealed core/shell quantum dots 120 would show a reduced quantum yield compared to the unannealed dots. To avoid this situation, the ZnS shell thickness needs to be increased to such an extent whereby the core/shell quantum dot electron wavefunction no longer samples the shell's surface states. Using calculational techniques well known in the art (S. A. Ivanov et al., Journal of Physical Chemistry 108, 10625 (2004)), the thickness of the ZnS shell needs to be at least 5 monolayers (ML) thick in order to negate the influence of the electron surface states. However, up to a 2 ML thick shell of ZnS can be directly grown on CdSe without the generation of defects due to the lattice mismatch between the two semiconductor lattices (D. V. Talapin et al., Journal of Physical Chemistry 108, 18826 (2004)). To avoid the lattice defects, an intermediate shell of ZnSe can be grown between the CdSe core and the ZnS outer shell. This approach was taken by Talapin et al. (D. V. Talapin et al., Journal of Physical Chemistry, B108, 18826 (2004)), where they were able to grow up to an 8 ML thick shell of ZnS on a CdSe core, with an optimum ZnSe shell thickness of 1.5 ML. More sophisticated approaches can also be taken to minimize the lattice mismatch difference, for instance, smoothly varying the semiconductor content of the intermediate shell from CdSe to ZnS over the distance of a number of monolayers (R. Xie et al., Journal of the American Chemical Society, 127, 7480 (2005)). In sum the thickness of the outer shell is made sufficiently thick so that neither free carrier samples the electronic surface states. Additionally, if necessary, intermediate shells of appropriate semiconductor content are added to the quantum dot in order to avoid the generation of defects associated with thick semiconductor shells 110. As a result of surface plasmon effects (K. B. Kahen, Applied Physics Letter 78, 1649 (2001)), having metal layers adjacent to emitter layers results in a loss in emitter efficiency. Consequently, it is advantageous to space the emitters' layers from any metal contacts by sufficiently thick (at least 150 nm) charge transport layers (e.g. 22, 24) or conductive layers (e.g. 12a, 16a). Finally, not only do transport layers inject electron and holes into the emitter layer, but, by proper choice of materials, they can prevent the leakage of the carriers back out of the emitter layer. For example, if the inorganic nanoparticles 140 were composed of ZnS0.5Se0.5 and the transport layers were composed of ZnS, then the electrons and holes would be confined to the emitter layer by the ZnS potential barrier. Suitable materials for the p-type transport layer include II-VI and III-V semiconductors. Typical II-VI semiconductors are ZnSe, ZnS, or ZnTe. Only ZnTe is naturally p-type, while ZnSe and ZnS are n-type. To get sufficiently high p-type conductivity, additional p-type dopants should be added to all three materials. For the case of II-VI p-type transport layers, possible candidate dopants are lithium and nitrogen. For example, it has been shown in the literature that Li3N can be diffused into ZnSe at ˜350° C. to create p-type ZnSe, with resistivities as low as 0.4 ohm-cm (S. W. Lim, Applied Physics Letters 65, 2437 (1994)). Suitable materials for n-type transport layers include II-VI and III-V semiconductors. Typical II-VI semiconductors are ZnSe or ZnS. As for p-type transport layers, to get sufficiently high n-type conductivity, additional n-type dopants should be added to the semiconductors. For the case of II-VI n-type transport layers, possible candidate dopants are the Type III dopants of Al, In, or Ga. As is well known in the art, these dopants can be added to the layer either by ion implantation (followed by an anneal) or by a diffusion process (P. J. George et al., Applied Physics Letter 66, 3624 [1995]). A more preferred route is to add the dopant in-situ during the chemical synthesis of the nanoparticle. Taking the example of ZnSe particles formed in a hexadecylamine (HDA)/TOPO coordinating solvent (M. A. Hines et al., Journal of Physical Chemistry B102, 3655 [1998]), the Zn source is diethylzinc in hexane and the Se source is Se powder dissolved in TOP (forming TOPSe). If the ZnSe were to be doped with Al, then a corresponding percentage (a few percent relative to the diethylzinc concentration) of trimethylaluminum in hexane would be added to a syringe containing TOP, TOPSe, and diethylzinc. In-situ doping processes, like these, have been successfully demonstrated when growing thin films by a chemical bath deposition process (J. Lee et al., Thin Solid Films 431-432, 344 [2003]). The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. PARTS LIST 1,3, 4,5 light rays 10 substrate 12 first electrode (transparent or reflective) 12a transparent conductive layer 12b reflective layer 14 colloidal light-emitting layer 16 second electrode (transparent or reflective) 16a transparent conductive layer 16b reflective layer 17 protective layer 18 light-emitting particles 19 gap 20 cover 22 charge-injecting, -transport, or -blocking layer 24 charge-injecting, -transport, or -blocking layer 25 light-emitting element 26 light-scattering particles 27 spacing between light-emitting elements 28 light-scattering layer 30 thin-film electronic components 31 organic light-emitting material 32 planarization and insulating layer 33 light-emissive layer 34 planarization and insulating layer 36 low-index layer, optical isolation layer 38 second layer 40 adhesive binder 41 openings 42 walls 66, 68 light 100 light-emitting core 110 shell 115 organic ligands 120 quantum dots 130 particle agglomeration 140 inorganic conductive nanoparticles t layer thickness
|
H
|
H01
|
H01J
|
1
|
63
|
|||
11810647
|
US20070281508A1-20071206
|
Electrical connector
|
ACCEPTED
|
20071122
|
20071206
|
[]
|
H01R1200
|
["H01R1200"]
|
7473105
|
20070606
|
20090106
|
439
|
071000
|
99649.0
|
LEON MUNOZ
|
EDWIN
|
[{"inventor_name_last": "Liao", "inventor_name_first": "Fang-Jun", "inventor_city": "Tu-Cheng", "inventor_state": "", "inventor_country": "TW"}, {"inventor_name_last": "Liu", "inventor_name_first": "Jia-Hau", "inventor_city": "Tu-Cheng", "inventor_state": "", "inventor_country": "TW"}, {"inventor_name_last": "Hsu", "inventor_name_first": "Shuo-Hsiu", "inventor_city": "Tu-Cheng", "inventor_state": "", "inventor_country": "TW"}]
|
An electrical connector (1) includes a connector body (51) holding a plurality of contacts (52). The connector body includes a base section (511) with four side walls (512) surrounded thereby to form an interior cavity adapted to receive an IC package. A datum protrusion (5120) is provided on each of two adjacent side walls and configured to laterally invade the interior cavity. A chamfered surface (513) is formed along a joint between each of two adjacent side walls and the base section, and further adjacent each of the datum protrusions, thereby avoiding stress generation around the joint between each side wall and the base section.
|
1. An electrical connector comprising: a connector body holding a plurality of contacts, the connector body including a base section with four side walls surrounded thereby to form an interior cavity adapted to receive an IC package; a datum protrusion provided on each of two adjacent side walls and configured to laterally invade said interior cavity; and a chamfered or curved surface formed along a joint between each of two adjacent side walls and said base section and adjacent said datum protrusion. 2. The electrical connector of claim 1, wherein each of two adjacent side walls is provided with at least three datum protrusions, each datum protrusion having an outer face facing towards the interior cavity, the outer faces of said at least three datum protrusions disposed in a coplanar manner. 3. The electrical connector of claim 1, wherein each of two adjacent side walls is provided with at least three datum protrusions, said at least three datum protrusions evenly arranged along a lengthwise edge of said side wall. 4. The electrical connector of claim 1, wherein an inspection window is formed on said base section and located proximate to each datum protrusion. 5. An electrical connector comprising: a connector body holding a plurality of contacts, the connector body including a base section with a plurality of side walls to thereby commonly form an interior cavity adapted to receive an IC package; and a plurality of datum protrusions provided on each of two adjacent side walls and configured to laterally invade said interior cavity; wherein each of said two adjacent side walls are equipped with at least three of said protrusions under a condition that a distance between every adjacent two protrusions is essentially similar to that between an outermost protrusion and a corresponding corner formed by said adjacent two sidewalls. 6. The electrical connector as claimed in claim 5, wherein the base defines a through opening vertically aligned with each of said protrusions under a condition that the protrusions are spaced from a top face of the base with a distance. 7. The electrical connector as claimed in claim 6, wherein said through opening is not smaller than a horizontal dimension of the corresponding protrusion. 8. An electrical connector comprising: a connector body holding a plurality of contacts, the connector body including a base section with a plurality of side walls to thereby commonly form an interior cavity adapted to receive an IC package; and a plurality of datum protrusions provided on each of two adjacent side walls and configured to laterally invade said interior cavity; wherein the base defines a through opening vertically aligned with each of said protrusions under a condition that the protrusions are spaced from a top face of the base with a distance. 9. The electrical connector as claimed in claim 8, wherein said through opening is not smaller than a horizontal dimension of the corresponding protrusion.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to the art of electrical connectors, and more particularly to an electrical connector for electrically connecting between an IC package with a substrate. 2. Description of the Related Art One conventional electrical connector 5 ′ is shown in FIG. 3 to include an insulative connector body 51 ′ with a plurality of contacts 52 ′ attached thereto. The connector body 51 ′ includes a base section 511 ′ with four side walls 512 ′ surrounded thereby to form an interior cavity adapted to receive an IC package (not shown). Each of two adjacent side walls 512 ′ is provided with a pair of datum protrusions 5120 ′, which are utilized to precisely locate the contacts and the IC package relative to the side walls 512 ′ of the connector body 51 ′. Typically, the IC package is loaded into the connector body 51 ′ so as to establish electrical continuity between the IC package and a substrate (not shown). Frequent loading processes of the IC package onto the connector body 51 ′ will result in stress concentration adjacent the datum protrusions 5120 ′, particularly around a joint portion between the base section 511 ′ and the respective side walls 512 ′, thereby causing the joint portion cracked or somewhat fragile undesirable to the user of the electrical connector 5 ′. Therefore, there is a need to provide a new electrical connector to resolve the above-mentioned shortcoming.
|
<SOH> SUMMARY OF THE INVENTION <EOH>An electrical connector according to one embodiment of the present invention includes a connector body holding a plurality of contacts. The connector body includes a base section with four side walls surrounded thereby to form an interior cavity adapted to receive an IC package. A datum protrusion is provided on each of two adjacent side walls and configured to laterally invade the interior cavity. A chamfered surface is formed along a joint between each of two adjacent side walls and the base section, and further adjacent each of the datum protrusions, thereby avoiding stress generation around the joint between each side wall and the base section. Other features and advantages of the present invention will become more apparent to those skilled in the art upon examination of the following drawings and detailed description of preferred embodiments, in which:
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the art of electrical connectors, and more particularly to an electrical connector for electrically connecting between an IC package with a substrate. 2. Description of the Related Art One conventional electrical connector 5′ is shown in FIG. 3 to include an insulative connector body 51′ with a plurality of contacts 52′ attached thereto. The connector body 51′ includes a base section 511′ with four side walls 512′ surrounded thereby to form an interior cavity adapted to receive an IC package (not shown). Each of two adjacent side walls 512′ is provided with a pair of datum protrusions 5120′, which are utilized to precisely locate the contacts and the IC package relative to the side walls 512′ of the connector body 51′. Typically, the IC package is loaded into the connector body 51′ so as to establish electrical continuity between the IC package and a substrate (not shown). Frequent loading processes of the IC package onto the connector body 51′ will result in stress concentration adjacent the datum protrusions 5120′, particularly around a joint portion between the base section 511′ and the respective side walls 512′, thereby causing the joint portion cracked or somewhat fragile undesirable to the user of the electrical connector 5′. Therefore, there is a need to provide a new electrical connector to resolve the above-mentioned shortcoming. SUMMARY OF THE INVENTION An electrical connector according to one embodiment of the present invention includes a connector body holding a plurality of contacts. The connector body includes a base section with four side walls surrounded thereby to form an interior cavity adapted to receive an IC package. A datum protrusion is provided on each of two adjacent side walls and configured to laterally invade the interior cavity. A chamfered surface is formed along a joint between each of two adjacent side walls and the base section, and further adjacent each of the datum protrusions, thereby avoiding stress generation around the joint between each side wall and the base section. Other features and advantages of the present invention will become more apparent to those skilled in the art upon examination of the following drawings and detailed description of preferred embodiments, in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an electrical connector according to an embodiment of the present invention; FIG. 2 is an enlarged view of a part “V” of the electrical connector of FIG. 1; and FIG. 3 is a perspective view of a conventional electrical connector. DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, an electrical connector 5 according to the embodiment is shown to include an insulative connector body 51 with a plurality of contacts 52 attached thereto. The electrical connector body 51 includes a base section 511 with four side walls 512 surrounded thereby to form an interior cavity adapted to receive an IC package (not shown). Each of two adjacent side walls 512 is provided with at least three datum protrusions 5120 evenly arranged along a length edge of each side wall 512, thereby forming additional force bearing points for the IC package after the IC package is loaded onto the connector body. Each datum protrusion 5120 has an outer face facing towards the interior cavity, with the outer faces of the datum protrusions 5120 disposed in a coplanar manner. The providence of additional datum protrusions 5120 can result in even force pushed against the IC package from the evenly-arranged datum protrusions 5120, thereby assuring the precise location of the IC package with respect to the peripheral side walls 512 of the connector body 51. Firstly, a chamfered/curved surface 513 is formed along a joint between each of two adjacent side walls 512 and the base section 511 and adjacent each datum protrusion 5120, and secondly the protrusion 5120 is spaced from a top face of the base section 511, thereby avoiding stress generation/concentration around the joint between each side wall 512 and the base section 511. In addition, an inspection window 5110 is formed on the base section 511 and proximate to each datum protrusion 5120, thereby enabling a measurement of the IC package in a first direction and a second direction substantially perpendicular to the first direction (as known in the prior art). In such a manner, registry of the IC package can be accurately controlled. While the present invention has been described with reference to preferred embodiments, the description of the invention is illustrative and is not to be construed as limiting the invention. Various of modifications to the present invention can be made to preferred embodiments by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.
|
H
|
H01
|
H01R
|
12
|
00
|
|||
11807388
|
US20070260944A1-20071108
|
Decoding LDPC (Low Density Parity Check) code and graphs using multiplication (or addition in log-domain) on both sides of bipartite graph
|
ACCEPTED
|
20071024
|
20071108
|
[]
|
G06K504
|
["G06K504"]
|
7464317
|
20070529
|
20081209
|
714
|
755000
|
73045.0
|
LAMARRE
|
GUY
|
[{"inventor_name_last": "Cameron", "inventor_name_first": "Kelly", "inventor_city": "Irvine", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Shen", "inventor_name_first": "Ba-Zhong", "inventor_city": "Irvine", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Tran", "inventor_name_first": "Hau", "inventor_city": "Irvine", "inventor_state": "CA", "inventor_country": "US"}]
|
Decoding LDPC (Low Density Parity Check) code and graphs using multiplication (or addition in log-domain) on both sides of bipartite graph. A means for decoding LDPC coded signals is presented whereby edge messages may be updated using only multiplication (or log domain addition). By appropriate modification of the various calculations that need to be performed when updating edge messages, the calculations may be reduced to only performing product of terms functions. When implementing such functionality in hardware within a communication device that is operable to decode LDPC coded signals, this reduction in processing complexity greatly eases the actual hardware's complexity as well. A significant savings in processing resources, memory, memory management concerns, and other performance driving parameters may be made.
|
1. A decoder that is operable to decode an LDPC (Low Density Parity Check) coded signal, the decoder comprising: a check node processing module that is operable to update a first plurality of check edge messages using a first plurality of bit edge messages by calculating a product of terms function wherein those terms correspond to the first plurality of bit edge messages thereby generating a second plurality of check edge messages; and a bit node processing module that is operable to update the first plurality of bit edge messages using the second plurality of check edge messages thereby generating a second plurality of bit edge messages; and wherein: the second plurality of bit edge messages is employed to make a soft estimate of at least one information bit encoded within the LDPC coded signal. 2. The decoder of claim 1, wherein: the first plurality of bit edge messages is an initialized plurality of bit edge messages. 3. The decoder of claim 1, wherein: at least one bit edge message of the first plurality of bit edge messages corresponds to a first edge that couples a first bit node to a first check node within an LDPC bipartite graph that corresponds to an LDPC code by which the LDPC coded signal is generated; and at least one check edge message of the first plurality of check edge messages corresponds to a second edge that couples a second check node to a second bit node within the LDPC bipartite graph that corresponds to the LDPC code by which the LDPC coded signal is generated. 4. The decoder of claim 1, wherein: the check node processing module and the bit node processing module are implemented within a single processor that is operable to perform both check node processing and bit node processing. 5. The decoder of claim 1, wherein: the check node processing module and the bit node processing module are implemented within a single processor that is operable to perform both check node processing and bit node processing; and the single processor is operable to generate the first plurality of bit edge messages which is an initialized plurality of bit edge messages. 6. The decoder of claim 1, further comprising: a hard limiter that is operable to make a hard estimate of the soft estimate of at least one information bit encoded within the LDPC coded signal; and a syndrome calculator module that is operable to employ the hard estimate to determine whether each syndrome of a plurality of syndromes associated with the LDPC code is equal to zero; and wherein: when, during a decoding iteration, the syndrome calculator determines that each syndrome of the plurality of syndromes associated with the LDPC code is equal to zero, then the decoding iteration is a final decoding iteration; and when, during the decoding iteration, the syndrome calculator determines that each syndrome of the plurality of syndromes associated with the LDPC code is not equal to zero, then the decoder is operable to perform at least one additional decoding iteration. 7. The decoder of claim 1, wherein: the bit node calculator functional block is operable to perform likelihood processing when updating the plurality of edge messages with respect to the plurality of bit nodes; and the check node operator functional block is operable to perform likelihood processing when updating the plurality of edge messages with respect to the plurality of check nodes. 8. The decoder of claim 1, wherein: the decoder is implemented within a communication device; and the communication device is implemented within at least one of a satellite communication system, an HDTV (High Definition Television) communication system, a cellular communication system, a microwave communication system, a point-to-point communication system, a unidirectional communication system, a bi-directional communication system, a one to many communication system, a fiber-optic communication system, a WLAN (Wireless Local Area Network) communication system, and a DSL (Digital Subscriber Line) communication system. 9. A decoder that is operable to decode an LDPC (Low Density Parity Check) coded signal, the decoder comprising: a check node processing module that is operable to update a first plurality of check edge messages using a first plurality of bit edge messages while operating in a logarithmic domain by calculating a sum of terms function wherein those terms correspond to the first plurality of bit edge messages thereby generating a second plurality of check edge messages; and a bit node processing module that is operable to update the first plurality of bit edge messages using the second plurality of check edge messages thereby generating a second plurality of bit edge messages; and wherein: the second plurality of bit edge messages is employed to make a soft estimate of at least one information bit encoded within the LDPC coded signal. 10. The decoder of claim 9, wherein: at least one bit edge message of the first plurality of bit edge messages corresponds to a first edge that couples a first bit node to a first check node within an LDPC bipartite graph that corresponds to an LDPC code by which the LDPC coded signal is generated; and at least one check edge message of the first plurality of check edge messages corresponds to a second edge that couples a second check node to a second bit node within the LDPC bipartite graph that corresponds to the LDPC code by which the LDPC coded signal is generated. 11. The decoder of claim 9, wherein: the check node processing module and the bit node processing module are implemented within a single processor that is operable to perform both check node processing and bit node processing. 12. The decoder of claim 9, wherein: the check node processing module and the bit node processing module are implemented within a single processor that is operable to perform both check node processing and bit node processing; and the single processor is operable to generate the first plurality of bit edge messages which is an initialized plurality of bit edge messages. 13. The decoder of claim 9, further comprising: a hard limiter that is operable to make a hard estimate of the soft estimate of at least one information bit encoded within the LDPC coded signal; and a syndrome calculator module that is operable to employ the hard estimate to determine whether each syndrome of a plurality of syndromes associated with the LDPC code is equal to zero; and wherein: when, during a decoding iteration, the syndrome calculator determines that each syndrome of the plurality of syndromes associated with the LDPC code is equal to zero, then the decoding iteration is a final decoding iteration; and when, during the decoding iteration, the syndrome calculator determines that each syndrome of the plurality of syndromes associated with the LDPC code is not equal to zero, then the decoder is operable to perform at least one additional decoding iteration. 14. The decoder of claim 9, wherein: the bit node calculator functional block is operable to perform likelihood processing when updating the plurality of edge messages with respect to the plurality of bit nodes; and the check node operator functional block is operable to perform likelihood processing when updating the plurality of edge messages with respect to the plurality of check nodes. 15. The decoder of claim 9, wherein: the decoder is implemented within a communication device; and the communication device is implemented within at least one of a satellite communication system, an HDTV (High Definition Television) communication system, a cellular communication system, a microwave communication system, a point-to-point communication system, a uni-directional communication system, a bi-directional communication system, a one to many communication system, a fiber-optic communication system, a WLAN (Wireless Local Area Network) communication system, and a DSL (Digital Subscriber Line) communication system. 16. A method for decoding an LDPC (Low Density Parity Check) coded signal, the method comprising: performing check node processing that includes updating a first plurality of check edge messages using a first plurality of bit edge messages by calculating a product of terms function wherein those terms correspond to the first plurality of bit edge messages thereby generating a second plurality of check edge messages; and performing bit node processing that includes updating the first plurality of bit edge messages using the second plurality of check edge messages thereby generating a second plurality of bit edge messages; and employing the second plurality of bit edge messages to make a soft estimate of at least one information bit encoded within the LDPC coded signal. 17. The method of claim 16, wherein: the check node processing and the bit node processing are both performed within a single processor. 18. The method of claim 16, wherein: at least one bit edge message of the first plurality of bit edge messages corresponds to a first edge that couples a first bit node to a first check node within an LDPC bipartite graph that corresponds to an LDPC code by which the LDPC coded signal is generated; and at least one check edge message of the first plurality of check edge messages corresponds to a second edge that couples a second check node to a second bit node within the LDPC bipartite graph that corresponds to the LDPC code by which the LDPC coded signal is generated. 19. The method of claim 16, further comprising: making a hard estimate of the soft estimate of at least one information bit encoded within the LDPC coded signal; employing the hard estimate to determine whether each syndrome of a plurality of syndromes associated with the LDPC code is equal to zero; when, during a decoding iteration, it is determined that each syndrome of the plurality of syndromes associated with the LDPC code is equal to zero, identifying the decoding iteration as a final decoding iteration; and when, during the decoding iteration, it is determined that each syndrome of the plurality of syndromes associated with the LDPC code is not equal to zero, performing at least one additional decoding iteration. 20. The method of claim 16, wherein: the method is performed within a decoder; the decoder is implemented within a communication device; and the communication device is implemented within at least one of a satellite communication system, an HDTV (High Definition Television) communication system, a cellular communication system, a microwave communication system, a point-to-point communication system, a unidirectional communication system, a bi-directional communication system, a one to many communication system, a fiber-optic communication system, a WLAN (Wireless Local Area Network) communication system, and a DSL (Digital Subscriber Line) communication system.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Technical Field of the Invention The invention relates generally to communication systems; and, more particularly, it relates to decoding of signals within such communication systems. 2. Description of Related Art Data communication systems have been under continual development for many years. One such type of communication system that has been of significant interest lately is a communication system that employs turbo codes. Another type of communication system that has also received interest is a communication system that employs LDPC (Low Density Parity Check) code. A primary directive in these areas of development has been to try continually to lower the error floor within a communication system. The ideal goal has been to try to reach Shannon's limit in a communication channel. Shannon's limit may be viewed as being the data rate to be used in a communication channel, having a particular SNR (Signal to Noise Ratio), that achieves error free transmission through the communication channel. In other words, the Shannon limit is the theoretical bound for channel capacity for a given modulation and code rate. LDPC code has been shown to provide for excellent decoding performance that can approach the Shannon limit in some cases. For example, some LDPC decoders have been shown to come within 0.3 dB (decibels) from the theoretical Shannon limit. While this example was achieved using an irregular LDPC code of a length of one million, it nevertheless demonstrates the very promising application of LDPC codes within communication systems. Typical encoding of LDPC coded modulation signals is performed by generating a signal that includes symbols each having a common code rate and being mapped to a singular modulation. That is to say, all of the symbols of such an LDPC coded modulation signal have the same code rate and the same modulation (the same constellation having a singular mapping). Oftentimes, such prior art encoding designs are implemented as to maximize the hardware and processing efficiencies of the particular design employed to generate the LDPC coded modulation signal having the single code rate and single modulation for all of the symbols generated therein. With respect to decoding of such LDPC coded modulation signals, decoding is most commonly performed based on a bipartite graph of a given LDPC code such that the graph includes both bit nodes and check nodes. The I, Q (In-phase, Quadrature) values associated with received symbols are associated with a symbol node, and that symbol node is associated with corresponding bit nodes. Bit metrics are then calculated for the individual bits of the corresponding symbols, and those bit metrics are provided to the bit nodes of the bipartite graph of the given LDPC code. Edge information corresponding to the edges (e.g., edge messages) that interconnect the bit nodes and the check nodes is calculated, and appropriately updated, and communicated back and forth between the bit nodes and the check nodes during iterative decoding of the LDPC coded signal. A common approach to performing bit decoding of such LDPC coded signals is to use the prior art a posteriori probability (APP) decoding approach of a graph code using so-called sum product algorithm (SPA). The following references described this prior art SPA decoding approach. [1] R. Gallager, Low - Density Parity - Check Codes , Cambridge, Mass.: MIT Press, 1963. [2] M. Luby, M. Mitzenmacher, M. A. Shokrollahi, D. A. Spielman, and V. Stemann, “Practical Loss-Resilient Codes”, Proc. 29 th Symp. on Theory of Computing, 1997, pp. 150-159. [3] D. J. C. MacKay, “Good error correcting codes based on very sparse matrices,” IEEE Trans. Inform. Theory , Vol. 45, pp. 399-431, March 1999. [4] G. D. Forney, “Codes on graphs: normal realizations,” IEEE Trans. Inform. Theory , Vol. 47, pp. 520-548, February 2001. Using the prior art SPA approach to decoding LDPC coded signals, the check node is estimated with a sum and a product of the estimation that is obtained from bit nodes. This combination of the sum and product terms is why this prior art approach is commonly referred to as the SPA approach (e.g., sum and product). Within this most common prior art SPA approach to bit decoding of LDPC coded signals, the approach operates by calculating APP of the LDPC graph code. This involves employing a number of different sum of terms functions (e.g., Σ), and then multiplying each of those respective sum of terms functions together using a product of terms functions (e.g., Π). This combination of performing the sum of terms functions and product of terms functions during each and every edge message updating iteration is extraordinarily computationally intensive. When implementing this approach to decoding LDPC coded signals, the hardware required to support and perform this combination of sum of terms functions and product of terms functions is very costly in terms of processing resources, memory, memory management concerns, etc. In the following, a brief introduction of this SPA approach to decoding LDPC coded signals is presented. Define the metric of bit node i by metric i (a)=Pr(y 1 |v 1 =a). To initialize the decoding processing, define bit e 0 (a)=metric b(e) (a). Then the check node estimate and the bit node estimate are performed as follows: 1. Check estimate: for every edge compute check e n ( a ) = Pr ( c c ( e ) = 0 ❘ v b ( e ) = a , y ) = ∑ u ∈ U e ( a ) ∏ ∫ ∈ E c ( c ( e ) ) ∖ { e } bit e ′ n - 1 ( u b ( f ) ) ; where U e ( a ) = { u 1 ∈ { 0 , 1 } , ( t , c ( e ) ∈ E c ( e ) ) ∖ { e } ❘ ∑ t u t = a } . 2. Bit estimate: For every edge e compute bit e n ( a ) = Pr ( v b ( e ) = a ❘ c c ( e ′ ) = 0 , f ∈ E v ( b ( e ) ) ∖ { e } , y ) bit e n ( a ) = metric b ( e ) ( a ) ∏ ∫ ∈ E v ( b ( e ) ) ∖ { e } check f n ( a ) ( EQ 2 ) The estimate at the n-th iteration is as follows: P ( n ) ( b i = a ❘ y ) = metric i ( a ) ∏ e ∈ E b ( i ) check e n ( a ) . In the application of graph codes on a communication system, the operation of the decoding is oftentimes actually implemented in the logarithm domain (e.g., the log domain). Multiplications may be implemented in the log domain using addition, and divisions may be implemented in the log domain using subtraction. Therefore, when using SPA approach to decoding LDPC coded signals, the logarithm of the sum of several values has to be carried out. This computational processing of summing over several values, when implemented in the log domain, may significantly increase the complexity of the hardware that is employed to implement a decoder that performs this SPA approach. As can clearly be seen, there is a need in the art to provide a new means by which LDPC coded signals may be decoded that is less computationally intensive. As such, a less computationally intensive approach could potentially be implemented more simplistically in hardware. If a less computationally intensive approach could be achieved, then a device implementing such approach could provide for a significant degree of savings in many measurable operational parameters including processing resources, memory, memory management concerns, etc.
|
<SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention is directed to apparatus and methods of operation that are further described in the following Brief Description of the Several Views of the Drawings, the Detailed Description of the Invention, and the claims. Other features and advantages of the present invention will become apparent from the following detailed description of the invention made with reference to the accompanying drawings.
|
CROSS REFERENCE TO RELATED PATENTS/PATENT APPLICATIONS Continuation priority claim, 35 U.S.C. § 120 The present U.S. Utility Patent Application claims priority pursuant to 35 U.S.C. § 120, as a continuation, to the following U.S. Utility Patent Application which is hereby incorporated herein by reference in its entirety and made part of the present U.S. Utility Patent Application for all purposes: 1. U.S. Utility application Ser. No. 10/865,556, entitled “Decoding LDPC (Low Density Parity Check) code and graphs using multiplication (or addition in log-domain) on both sides of bipartite graph,” (Attorney Docket No. BP3243), filed 06-10-2004, pending, which claims priority pursuant to 35 U.S.C. § 119(e) to the following U.S. Provisional Patent Application which is hereby incorporated herein by reference in its entirety and made part of the present U.S. Utility Patent Application for all purposes: a. U.S. Provisional Application Ser. No. 60/567,571, “Decoding LDPC (Low Density Parity Check) code and graphs using multiplication (or addition in log-domain) on both sides of bipartite graph,” (Attorney Docket No. BP3243), filed 05-03-2004. BACKGROUND OF THE INVENTION 1. Technical Field of the Invention The invention relates generally to communication systems; and, more particularly, it relates to decoding of signals within such communication systems. 2. Description of Related Art Data communication systems have been under continual development for many years. One such type of communication system that has been of significant interest lately is a communication system that employs turbo codes. Another type of communication system that has also received interest is a communication system that employs LDPC (Low Density Parity Check) code. A primary directive in these areas of development has been to try continually to lower the error floor within a communication system. The ideal goal has been to try to reach Shannon's limit in a communication channel. Shannon's limit may be viewed as being the data rate to be used in a communication channel, having a particular SNR (Signal to Noise Ratio), that achieves error free transmission through the communication channel. In other words, the Shannon limit is the theoretical bound for channel capacity for a given modulation and code rate. LDPC code has been shown to provide for excellent decoding performance that can approach the Shannon limit in some cases. For example, some LDPC decoders have been shown to come within 0.3 dB (decibels) from the theoretical Shannon limit. While this example was achieved using an irregular LDPC code of a length of one million, it nevertheless demonstrates the very promising application of LDPC codes within communication systems. Typical encoding of LDPC coded modulation signals is performed by generating a signal that includes symbols each having a common code rate and being mapped to a singular modulation. That is to say, all of the symbols of such an LDPC coded modulation signal have the same code rate and the same modulation (the same constellation having a singular mapping). Oftentimes, such prior art encoding designs are implemented as to maximize the hardware and processing efficiencies of the particular design employed to generate the LDPC coded modulation signal having the single code rate and single modulation for all of the symbols generated therein. With respect to decoding of such LDPC coded modulation signals, decoding is most commonly performed based on a bipartite graph of a given LDPC code such that the graph includes both bit nodes and check nodes. The I, Q (In-phase, Quadrature) values associated with received symbols are associated with a symbol node, and that symbol node is associated with corresponding bit nodes. Bit metrics are then calculated for the individual bits of the corresponding symbols, and those bit metrics are provided to the bit nodes of the bipartite graph of the given LDPC code. Edge information corresponding to the edges (e.g., edge messages) that interconnect the bit nodes and the check nodes is calculated, and appropriately updated, and communicated back and forth between the bit nodes and the check nodes during iterative decoding of the LDPC coded signal. A common approach to performing bit decoding of such LDPC coded signals is to use the prior art a posteriori probability (APP) decoding approach of a graph code using so-called sum product algorithm (SPA). The following references described this prior art SPA decoding approach. [1] R. Gallager, Low-Density Parity-Check Codes, Cambridge, Mass.: MIT Press, 1963. [2] M. Luby, M. Mitzenmacher, M. A. Shokrollahi, D. A. Spielman, and V. Stemann, “Practical Loss-Resilient Codes”, Proc. 29th Symp. on Theory of Computing, 1997, pp. 150-159. [3] D. J. C. MacKay, “Good error correcting codes based on very sparse matrices,” IEEE Trans. Inform. Theory, Vol. 45, pp. 399-431, March 1999. [4] G. D. Forney, “Codes on graphs: normal realizations,” IEEE Trans. Inform. Theory, Vol. 47, pp. 520-548, February 2001. Using the prior art SPA approach to decoding LDPC coded signals, the check node is estimated with a sum and a product of the estimation that is obtained from bit nodes. This combination of the sum and product terms is why this prior art approach is commonly referred to as the SPA approach (e.g., sum and product). Within this most common prior art SPA approach to bit decoding of LDPC coded signals, the approach operates by calculating APP of the LDPC graph code. This involves employing a number of different sum of terms functions (e.g., Σ), and then multiplying each of those respective sum of terms functions together using a product of terms functions (e.g., Π). This combination of performing the sum of terms functions and product of terms functions during each and every edge message updating iteration is extraordinarily computationally intensive. When implementing this approach to decoding LDPC coded signals, the hardware required to support and perform this combination of sum of terms functions and product of terms functions is very costly in terms of processing resources, memory, memory management concerns, etc. In the following, a brief introduction of this SPA approach to decoding LDPC coded signals is presented. Define the metric of bit node i by metrici(a)=Pr(y1|v1=a). To initialize the decoding processing, define bite0(a)=metricb(e)(a). Then the check node estimate and the bit node estimate are performed as follows: 1. Check estimate: for every edge compute check e n ( a ) = Pr ( c c ( e ) = 0 ❘ v b ( e ) = a , y ) = ∑ u ∈ U e ( a ) ∏ ∫ ∈ E c ( c ( e ) ) ∖ { e } bit e ′ n - 1 ( u b ( f ) ) ; where U e ( a ) = { u 1 ∈ { 0 , 1 } , ( t , c ( e ) ∈ E c ( e ) ) ∖ { e } ❘ ∑ t u t = a } . 2. Bit estimate: For every edge e compute bit e n ( a ) = Pr ( v b ( e ) = a ❘ c c ( e ′ ) = 0 , f ∈ E v ( b ( e ) ) ∖ { e } , y ) bit e n ( a ) = metric b ( e ) ( a ) ∏ ∫ ∈ E v ( b ( e ) ) ∖ { e } check f n ( a ) ( EQ 2 ) The estimate at the n-th iteration is as follows: P ( n ) ( b i = a ❘ y ) = metric i ( a ) ∏ e ∈ E b ( i ) check e n ( a ) . In the application of graph codes on a communication system, the operation of the decoding is oftentimes actually implemented in the logarithm domain (e.g., the log domain). Multiplications may be implemented in the log domain using addition, and divisions may be implemented in the log domain using subtraction. Therefore, when using SPA approach to decoding LDPC coded signals, the logarithm of the sum of several values has to be carried out. This computational processing of summing over several values, when implemented in the log domain, may significantly increase the complexity of the hardware that is employed to implement a decoder that performs this SPA approach. As can clearly be seen, there is a need in the art to provide a new means by which LDPC coded signals may be decoded that is less computationally intensive. As such, a less computationally intensive approach could potentially be implemented more simplistically in hardware. If a less computationally intensive approach could be achieved, then a device implementing such approach could provide for a significant degree of savings in many measurable operational parameters including processing resources, memory, memory management concerns, etc. BRIEF SUMMARY OF THE INVENTION The present invention is directed to apparatus and methods of operation that are further described in the following Brief Description of the Several Views of the Drawings, the Detailed Description of the Invention, and the claims. Other features and advantages of the present invention will become apparent from the following detailed description of the invention made with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 is a system diagram illustrating an embodiment of a satellite communication system that is built according to the invention. FIG. 2 is a system diagram illustrating an embodiment of an HDTV (High Definition Television) communication system that is built according to the invention. FIG. 3A and FIG. 3B are system diagrams illustrating embodiment of uni-directional cellular communication systems that are built according to the invention. FIG. 4 is a system diagram illustrating an embodiment of a bi-directional cellular communication system that is built according to the invention. FIG. 5 is a system diagram illustrating an embodiment of a uni-directional microwave communication system that is built according to the invention. FIG. 6 is a system diagram illustrating an embodiment of a bi-directional microwave communication system that is built according to the invention. FIG. 7 is a system diagram illustrating an embodiment of a uni-directional point-to-point radio communication system that is built according to the invention. FIG. 8 is a system diagram illustrating an embodiment of a bi-directional point-to-point radio communication system that is built according to the invention. FIG. 9 is a system diagram illustrating an embodiment of a uni-directional communication system that is built according to the invention. FIG. 10 is a system diagram illustrating an embodiment of a bi-directional communication system that is built according to the invention. FIG. 11 is a system diagram illustrating an embodiment of a one to many communication system that is built according to the invention. FIG. 12 is a diagram illustrating an embodiment of a WLAN (Wireless Local Area Network) that may be implemented according to the invention. FIG. 13 is a diagram illustrating an embodiment of a DSL (Digital Subscriber Line) communication system that may be implemented according to the invention. FIG. 14 is a system diagram illustrating an embodiment of a fiber-optic communication system that is built according to the invention. FIG. 15 is a system diagram illustrating an embodiment of a satellite receiver STB (Set Top Box) system that is built according to the invention. FIG. 16 is a schematic block diagram illustrating a communication system that includes a plurality of base stations and/or access points, a plurality of wireless communication devices and a network hardware component in accordance with certain aspects of the invention. FIG. 17 is a schematic block diagram illustrating a wireless communication device that includes the host device and an associated radio in accordance with certain aspects of the invention. FIG. 18 is a diagram illustrating an alternative embodiment of a wireless communication device that is constructed according to the invention. FIG. 19 is a diagram illustrating an embodiment of an LDPC (Low Density Parity Check) code bipartite graph. FIG. 20 is a diagram illustrating an embodiment of LDPC (Low Density Parity Check) decoding functionality using bit metric according to the invention. FIG. 21 is a diagram illustrating an alternative embodiment of LDPC decoding functionality using bit metric according to the invention (when performing n number of iterations). FIG. 22 is a diagram illustrating an alternative embodiment of LDPC (Low Density Parity Check) decoding functionality using bit metric (with bit metric updating) according to the invention. FIG. 23 is a diagram illustrating an alternative embodiment of LDPC decoding functionality using bit metric (with bit metric updating) according to the invention (when performing n number of iterations). FIG. 24A is a diagram illustrating bit decoding using bit metric (shown with respect to an LDPC (Low Density Parity Check) code bipartite graph) according to the invention. FIG. 24B is a diagram illustrating bit decoding using bit metric updating (shown with respect to an LDPC (Low Density Parity Check) code bipartite graph) according to the invention. FIG. 25 is a diagram illustrating an embodiment of check node and bit node estimation functionality (employing likelihood decoding at check node side) according to the invention. FIG. 26 is a diagram illustrating an embodiment of LDPC decoding functionality (employing likelihood processing on both check nodes and bit nodes) according to the invention. FIG. 27 is a diagram illustrating an embodiment of LDPC decoding functionality (employing LR (Likelihood Ratio) processing on bit nodes) implemented in log domain according to the invention. FIG. 28 is a diagram illustrating an embodiment of check node and bit node estimation functionality (employing LR (Likelihood Ratio) decoding at check node side) according to the invention. FIG. 29 is a diagram illustrating an embodiment of LDPC decoding functionality (employing LLR (Log Likelihood Ratio) processing) according to the invention. FIG. 30 is a diagram illustrating an embodiment of check node processing functionality employing function L (shown using LDPC decoding employing LLR processing) according to the invention. FIG. 31A is a diagram illustrating an embodiment of separate check node processing and bit node processing functional blocks. FIG. 31B is a diagram illustrating an embodiment of a single functional block that is operable to perform calculations of both check node processing and bit node processing according to the invention. FIG. 32 is a diagram illustrating an embodiment of a single functional block (e.g., processor) that is operable to perform calculations for edge message initialization, check node processing, and bit node processing according to the invention. FIG. 33 is a flowchart illustrating an embodiment of a method for decoding LDPC coded signals using only multiplication (or log domain addition) on both sides of LDPC bipartite graph according to the invention. FIG. 34 is a flowchart illustrating an alternative embodiment of a method for decoding LDPC coded signals using only multiplication (or log domain addition) on both sides of LDPC bipartite graph according to the invention. DETAILED DESCRIPTION OF THE INVENTION Various decoding aspects of the invention may be found in devices that perform decoding of LDPC (Low Density Parity Check) coded signals such that the updating of edge messages (in the context of the iterative decoding processing) can be performed using more simplified calculations as opposed to the prior art approaches that include using the prior art SPA (sum product algorithm) decoding approach. In contradistinction to the prior art SPA decoding approach that involves calculating the relatively cumbersome and complex calculations that employ a number of different sum of terms functions (e.g., Σ), and then multiplying each of those respective sum of terms functions together using a product of terms functions (e.g., Π), one aspect of the invention involves reducing this computational complex processing (e.g., involving both number of different sum of terms functions (e.g., Σ) and product of terms functions (e.g., Π)) down to a straightforward product of terms function (e.g., Π). For example, when performing the iterative decoding processing in accordance with the LDPC decoding performed according to the invention, the updating of each edge message with respect to the check nodes may be performed by calculating a product of terms function such that the terms of that function include each of the corresponding edge messages with respect the plurality of bit nodes. That is to say, the updating of each edge message with respect to the check nodes involves a straightforward product of terms function (e.g., Π) operating on the terms of the corresponding edge messages with respect the plurality of bit nodes (e.g., corresponding to those edges that communicatively couple the check node of interest to its corresponding bit nodes). That is to say, this current check node of interest includes at least one edge that communicatively couples from this check node to at least one bit node. The updating of the edge messages corresponding to this check node involves a straightforward product of terms function (e.g., n) that operates on the corresponding edge messages corresponding to these particular bit nodes. This novel decoding approach is a significant departure from the prior art approaches to performing the SPA decoding approach, in that, the combination of performing multiple sum of terms functions (e.g., Σ) and then performing a product of terms function (e.g., Π) of those sum of term results need not be performed during each decoding iteration. This can provide a significant reduction in computational complexity and the resources needed to support and perform such cumbersome calculations. It is also noted that any of the product of terms functions (e.g., Π) that are performed in accordance with the invention may alternatively be implemented to be sum of terms functions (e.g., Σ) when implemented in the log domain. Any of the various embodiments of the invention may be implemented in the base 10 decimal domain or the log domain without departing from the scope and spirit of the invention. In some instances, the implementation is easier when implementing in the log domain. When performing the iterative decoding processing in the log domain, the calculations may also involve calculating various sign functions as well. For example, when implementing the calculations in the log domain (where multiplications may be performed as additions), there may also be a need to calculate appropriate corresponding sign functions. As is described in greater detail below, an appropriately implemented mapping may be employed so that the updating of the edge messages can be performed using only a product of terms function (or an equivalent log domain sum of terms function) for the check nodes (as opposed to the SPA processing of the prior art). By eliminating this first need to perform each of the different sum of terms functions and then perform a product of terms functions of each of the results of those different sum of terms functions, a significant savings in processing is achieved when updating the edge messages employing within the decoding processing of LDPC coded signals Generally speaking, various aspects of the invention may be found in any number of devices that perform decoding of LDPC coded signals. Sometimes, these devices support bi-directional communication and are implemented to perform both encoding and decoding of LDPC coded signals. Moreover, in some embodiments, encoding may be performed by combining LDPC encoding and modulation encoding to generate an LDPC coded signal. In some instances of the invention, the LDPC encoding is combined with modulation encoding in such a way as to generate a variable modulation signal whose modulation may vary as frequently as on a symbol by symbol basis. That is to say, the constellation and/or mapping of the symbols of an LDPC coded variable modulation signal may vary as frequently as on a symbol by symbol basis. In addition, the code rate of the symbols of the coded signal may also vary as frequently as on a symbol by symbol basis. In general, an LDPC signal generated according these encoding aspects may be characterized as a variable code rate and/or modulation signal. The novel approaches to decoding of LDPC coded signals that is presented herein, can be applied to any of these various types of LDPC coded signals (e.g., straight-forward LDPC coded signals, LDPC coded modulation signals, LDPC variable modulation signal, LDPC variable code rate signals, and so on). The simplified calculations required to perform iterative decoding processing of LDPC coded signals are significantly reduced in complexity by various aspects of the invention. Various communication devices and communication system embodiments are described below in which many of the various aspects of the invention may be implemented. In general, any communication device that performs encoding and/or decoding of LDPC coded signals may benefit from the invention; the LDPC decoding performs updating of edge messages using only multiplication (or log domain addition) on both sides of LDPC bipartite graph. Also, this encoding and/or decoding may also include processing those LDPC coded signals that have variable code rate and/or modulation as well as those that include combined LDPC coding and modulation coding. FIG. 1 is a system diagram illustrating an embodiment of a satellite communication system that is built according to the invention. A satellite transmitter is communicatively coupled to a satellite dish that is operable to communicate with a satellite. The satellite transmitter may also be communicatively coupled to a wired network. This wired network may include any number of networks including the Internet, proprietary networks, other wired networks and/or WANs (Wide Area Networks). The satellite transmitter employs the satellite dish to communicate to the satellite via a wireless communication channel. The satellite is able to communicate with one or more satellite receivers (each having a satellite dish). Each of the satellite receivers may also be communicatively coupled to a display. Here, the communication to and from the satellite may cooperatively be viewed as being a wireless communication channel, or each of the communication links to and from the satellite may be viewed as being two distinct wireless communication channels. For example, the wireless communication “channel” may be viewed as not including multiple wireless hops in one embodiment. In other multi-hop embodiments, the satellite receives a signal received from the satellite transmitter (via its satellite dish), amplifies it, and relays it to satellite receiver (via its satellite dish); the satellite receiver may also be implemented using terrestrial receivers such as satellite receivers, satellite based telephones, and/or satellite based Internet receivers, among other receiver types. In the case where the satellite receives a signal received from the satellite transmitter (via its satellite dish), amplifies it, and relays it, the satellite may be viewed as being a “transponder;” this is a multi-hop embodiment. In addition, other satellites may exist that perform both receiver and transmitter operations in cooperation with the satellite. In this case, each leg of an up-down transmission via the wireless communication channel would be considered separately. In whichever embodiment, the satellite communicates with the satellite receiver. The satellite receiver may be viewed as being a mobile unit in certain embodiments (employing a local antenna); alternatively, the satellite receiver may be viewed as being a satellite earth station that may be communicatively coupled to a wired network in a similar manner in which the satellite transmitter may also be communicatively coupled to a wired network. The satellite transmitter is operable to encode information (using an encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the satellite transmitter and the satellite receiver. The satellite receiver is operable to decode a signal (using a decoder) received from the communication channel in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows one embodiment where one or more of the various aspects of the invention may be found. FIG. 2 is a system diagram illustrating an embodiment of an HDTV (High Definition Television) communication system that is built according to the invention. An HDTV transmitter is communicatively coupled to a tower. The HDTV transmitter, using its tower, transmits a signal to a local tower dish via a wireless communication channel. The local tower dish may communicatively couple to an HDTV STB (Set Top Box) receiver via a coaxial cable. The HDTV STB receiver includes the functionality to receive the wireless transmitted signal that has been received by the local tower dish. This functionality may include any transformation and/or down-converting that may be needed to accommodate for any up-converting that may have been performed before and during transmission of the signal from the HDTV transmitter and its corresponding tower to transform the signal into a format that is compatible with the communication channel across which it is transmitted. For example, certain communication systems step a signal that is to be transmitted from a baseband signal to an IF (Intermediate Frequency) signal, and then to a carrier frequency signal before launching the signal into a communication channel. Alternatively, some communication systems perform a conversion directly from baseband to carrier frequency before launching the signal into a communication channel. In whichever case is employed within the particular embodiment, the HDTV STB receiver is operable to perform any down-converting that may be necessary to transform the received signal to a baseband signal that is appropriate for demodulating and decoding to extract the information there from. The HDTV STB receiver is also communicatively coupled to an HDTV display that is able to display the demodulated and decoded wireless transmitted signals received by the HDTV STB receiver and its local tower dish. The HDTV STB receiver may also be operable to process and output standard definition television signals as well. For example, when the HDTV display is also operable to display standard definition television signals, and when certain video/audio is only available in standard definition format, then the HDTV STB receiver is operable to process those standard definition television signals for use by the HDTV display. The HDTV transmitter (via its tower) transmits a signal directly to the local tower dish via the wireless communication channel in this embodiment. In alternative embodiments, the HDTV transmitter may first receive a signal from a satellite, using a satellite earth station that is communicatively coupled to the HDTV transmitter, and then transmit this received signal to the local tower dish via the wireless communication channel. In this situation, the HDTV transmitter operates as a relaying element to transfer a signal originally provided by the satellite that is ultimately destined for the HDTV STB receiver. For example, another satellite earth station may first transmit a signal to the satellite from another location, and the satellite may relay this signal to the satellite earth station that is communicatively coupled to the HDTV transmitter. In such a case the HDTV transmitter include transceiver functionality such that it may first perform receiver functionality and then perform transmitter functionality to transmit this received signal to the local tower dish. In even other embodiments, the HDTV transmitter employs its satellite earth station to communicate to the satellite via a wireless communication channel. The satellite is able to communicate with a local satellite dish; the local satellite dish communicatively couples to the HDTV STB receiver via a coaxial cable. This path of transmission shows yet another communication path where the HDTV STB receiver may communicate with the HDTV transmitter. In whichever embodiment and by whichever signal path the HDTV transmitter employs to communicate with the HDTV STB receiver, the HDTV STB receiver is operable to receive communication transmissions from the HDTV transmitter and to demodulate and decode them appropriately. The HDTV transmitter is operable to encode information (using an encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the HDTV transmitter and the HDTV STB receiver. The HDTV STB receiver is operable to decode a signal (using a decoder) received from the communication channel in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 3A and FIG. 3B are system diagrams illustrating embodiments of uni-directional cellular communication systems that are built according to the invention. Referring to the FIG. 3A, a mobile transmitter includes a local antenna communicatively coupled thereto. The mobile transmitter may be any number of types of transmitters including a one way cellular telephone, a wireless pager unit, a mobile computer having transmission functionality, or any other type of mobile transmitter. The mobile transmitter transmits a signal, using its local antenna, to a cellular tower via a wireless communication channel. The cellular tower is communicatively coupled to a base station receiver; the receiving tower is operable to receive data transmission from the local antenna of the mobile transmitter that has been communicated via the wireless communication channel. The cellular tower communicatively couples the received signal to the base station receiver. The mobile transmitter is operable to encode information (using an encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the mobile transmitter and the base station receiver. The base station receiver is operable to decode a signal (using a decoder) received from the communication channel in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. Referring to the FIG. 3B, a base station transmitter includes a cellular tower communicatively coupled thereto. The base station transmitter, using its cellular tower, transmits a signal to a mobile receiver via a communication channel. The mobile receiver may be any number of types of receivers including a one-way cellular telephone, a wireless pager unit, a mobile computer having receiver functionality, or any other type of mobile receiver. The mobile receiver is communicatively coupled to a local antenna; the local antenna is operable to receive data transmission from the cellular tower of the base station transmitter that has been communicated via the wireless communication channel. The local antenna communicatively couples the received signal to the mobile receiver. The base station transmitter is operable to encode information (using an encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the base station transmitter and the mobile receiver. The mobile receiver is operable to decode a signal (using a decoder) received from the communication channel in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 4 is a system diagram illustrating an embodiment of a bi-directional cellular communication system, built according to the invention, where the communication can go to and from the base station transceiver and to and from the mobile transceiver via the wireless communication channel. Referring to the FIG. 4, a base station transceiver includes a cellular tower communicatively coupled thereto. The base station transceiver, using its cellular tower, transmits a signal to a mobile transceiver via a communication channel. The reverse communication operation may also be performed. The mobile transceiver is able to transmit a signal to the base station transceiver as well. The mobile transceiver may be any number of types of transceivers including a cellular telephone, a wireless pager unit, a mobile computer having transceiver functionality, or any other type of mobile transceiver. The mobile transceiver is communicatively coupled to a local antenna; the local antenna is operable to receive data transmission from the cellular tower of the base station transceiver that has been communicated via the wireless communication channel. The local antenna communicatively couples the received signal to the mobile transceiver. The base station transceiver is operable to encode information (using its corresponding encoder) that is to be transmitted to the mobile transceiver. The mobile transceiver is operable to decode the transmitted signal (using its corresponding decoder). Similarly, mobile transceiver is operable to encode information (using its corresponding encoder) that is to be transmitted to the base station transceiver; the base station transceiver is operable to decode the transmitted signal (using its corresponding decoder). As within other embodiments that employ an encoder and a decoder, the encoder of either of the base station transceiver or the mobile transceiver may be implemented to encode information (using its corresponding encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the base station transceiver and the mobile transceiver. The decoder of either of the base station transceiver or the mobile transceiver may be implemented to decode the transmitted signal (using its corresponding decoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 5 is a system diagram illustrating an embodiment of a uni-directional microwave communication system that is built according to the invention. A microwave transmitter is communicatively coupled to a microwave tower. The microwave transmitter, using its microwave tower, transmits a signal to a microwave tower via a wireless communication channel. A microwave receiver is communicatively coupled to the microwave tower. The microwave tower is able to receive transmissions from the microwave tower that have been communicated via the wireless communication channel. The microwave transmitter is operable to encode information (using an encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the microwave transmitter and the microwave receiver. The microwave receiver is operable to decode a signal (using a decoder) received from the communication channel in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 6 is a system diagram illustrating an embodiment of a bi-directional microwave communication system that is built according to the invention. Within the FIG. 6, a first microwave transceiver is communicatively coupled to a first microwave tower. The first microwave transceiver, using the first microwave tower (the first microwave transceiver's microwave tower), transmits a signal to a second microwave tower of a second microwave transceiver via a wireless communication channel. The second microwave transceiver is communicatively coupled to the second microwave tower (the second microwave transceiver's microwave tower). The second microwave tower is able to receive transmissions from the first microwave tower that have been communicated via the wireless communication channel. The reverse communication operation may also be performed using the first and second microwave transceivers. Each of the microwave transceivers is operable to encode information (using its corresponding encoder) that is to be transmitted the other microwave transceiver. Each microwave transceiver is operable to decode the transmitted signal (using its corresponding decoder) that it receives. Each of the microwave transceivers includes an encoder and a decoder. As within other embodiments that employ an encoder and a decoder, the encoder of either of the microwave transceivers may be implemented to encode information (using its corresponding encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the microwave transceivers. The decoder of either of the microwave transceivers may be implemented to decode the transmitted signal (using its corresponding decoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 7 is a system diagram illustrating an embodiment of a unidirectional point-to-point radio communication system, built according to the invention, where the communication goes from a mobile unit transmitter to a mobile unit receiver via the wireless communication channel. A mobile unit transmitter includes a local antenna communicatively coupled thereto. The mobile unit transmitter, using its local antenna, transmits a signal to a local antenna of a mobile unit receiver via a wireless communication channel. The mobile unit transmitter is operable to encode information (using an encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the mobile unit transmitter and the mobile unit receiver. The mobile unit receiver is operable to decode a signal (using a decoder) received from the communication channel in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 8 is a system diagram illustrating an embodiment of a bi-directional point-to-point radio communication system that is built according to the invention. A first mobile unit transceiver is communicatively coupled to a first local antenna. The first mobile unit transceiver, using the first local antenna (the first mobile unit transceiver's local antenna), transmits a signal to a second local antenna of a second mobile unit transceiver via a wireless communication channel. The second mobile unit transceiver is communicatively coupled to the second local antenna (the second mobile unit transceiver's local antenna). The second local antenna is able to receive transmissions from the first local antenna that have been communicated via the communication channel. The reverse communication operation may also be performed using the first and second mobile unit transceivers. Each of the mobile unit transceivers is operable to encode information (using its corresponding encoder) that is to be transmitted the other mobile unit transceiver. Each mobile unit transceiver is operable to decode the transmitted signal (using its corresponding decoder) that it receives. Each of the mobile unit transceivers includes an encoder and a decoder. As within other embodiments that employ an encoder and a decoder, the encoder of either of the mobile unit transceivers may be implemented to encode information (using its corresponding encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the mobile unit transceivers. The decoder of either of the mobile unit transceivers may be implemented to decode the transmitted signal (using its corresponding decoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 9 is a system diagram illustrating an embodiment of a uni-directional communication system that is built according to the invention. A transmitter communicates to a receiver via a uni-directional communication channel. The uni-directional communication channel may be a wireline (or wired) communication channel or a wireless communication channel without departing from the scope and spirit of the invention. The wired media by which the uni-directional communication channel may be implemented are varied, including coaxial cable, fiber-optic cabling, and copper cabling, among other types of “wiring.” Similarly, the wireless manners in which the uni-directional communication channel may be implemented are varied, including satellite communication, cellular communication, microwave communication, and radio communication, among other types of wireless communication. The transmitter is operable to encode information (using an encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the transmitter and the receiver. The receiver is operable to decode a signal (using a decoder) received from the communication channel in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 10 is a system diagram illustrating an embodiment of a bi-directional communication system that is built according to the invention. A first transceiver is communicatively coupled to a second transceiver via a bi-directional communication channel. The bi-directional communication channel may be a wireline (or wired) communication channel or a wireless communication channel without departing from the scope and spirit of the invention. The wired media by which the bi-directional communication channel may be implemented are varied, including coaxial cable, fiber-optic cabling, and copper cabling, among other types of “wiring.” Similarly, the wireless manners in which the bi-directional communication channel may be implemented are varied, including satellite communication, cellular communication, microwave communication, and radio communication, among other types of wireless communication. Each of the transceivers is operable to encode information (using its corresponding encoder) that is to be transmitted the other transceiver. Each transceiver is operable to decode the transmitted signal (using its corresponding decoder) that it receives. Each of the transceivers includes an encoder and a decoder. As within other embodiments that employ an encoder and a decoder, the encoder of either of the transceivers may be implemented to encode information (using its corresponding encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the transceivers. The decoder of either of the transceivers may be implemented to decode the transmitted signal (using its corresponding decoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 11 is a system diagram illustrating an embodiment of a one to many communication system that is built according to the invention. A transmitter is able to communicate, via broadcast in certain embodiments, with a number of receivers, shown as receivers 1, 2, . . . , n via a uni-directional communication channel. The uni-directional communication channel may be a wireline (or wired) communication channel or a wireless communication channel without departing from the scope and spirit of the invention. The wired media by which the communication channel may be implemented are varied, including coaxial cable, fiber-optic cabling, and copper cabling, among other types of “wiring.” Similarly, the wireless manners in which the communication channel may be implemented are varied, including satellite communication, cellular communication, microwave communication, and radio communication, among other types of wireless communication. A distribution point is employed within the one to many communication system to provide the appropriate communication to the receivers 1, 2, . . . , and n. In certain embodiments, the receivers 1, 2, . . . , and n each receive the same communication and individually discern which portion of the total communication is intended for them. The transmitter is operable to encode information (using an encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the transmitter and the receivers 1, 2, . . . , and n. Each of the receivers 1, 2, . . . , and n is operable to decode a signal (using a corresponding decoder) received from the communication channel in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 12 is a diagram illustrating an embodiment of a WLAN (Wireless Local Area Network) communication system that may be implemented according to the invention. The WLAN communication system may be implemented to include a number of devices that are all operable to communicate with one another via the WLAN. For example, the various devices that each include the functionality to interface with the WLAN may include any 1 or more of a laptop computer, a television, a PC (Personal Computer), a pen computer (that may be viewed as being a PDA (Personal Digital Assistant) in some instances, a personal electronic planner, or similar device), a mobile unit (that may be viewed as being a telephone, a pager, or some other mobile WLAN operable device), and/or a stationary unit (that may be viewed as a device that typically resides in a single location within the WLAN). The antennae of any of the various WLAN interactive devices may be integrated into the corresponding devices without departing from the scope and spirit of the invention as well. This illustrated group of devices that may interact with the WLAN is not intended to be an exhaustive list of devices that may interact with a WLAN, and a generic device shown as a WLAN interactive device represents any communication device that includes the functionality in order to interactive with the WLAN itself and/or the other devices that are associated with the WLAN. Any one of these devices that associate with the WLAN may be viewed generically as being a WLAN interactive device without departing from the scope and spirit of the invention. Each of the devices and the WLAN interactive device may be viewed as being located at nodes of the WLAN. It is also noted that the WLAN itself may also include functionality to allow interfacing with other networks as well. These external networks may generically be referred to as WANs (Wide Area Networks). For example, the WLAN may include an Internet I/F (interface) that allows for interfacing to the Internet itself. This Internet I/F may be viewed as being a base station device for the WLAN that allows any one of the WLAN interactive devices to access the Internet. It is also noted that the WLAN may also include functionality to allow interfacing with other networks (e.g., other WANs) besides simply the Internet. For example, the WLAN may include a microwave tower I/F that allows for interfacing to a microwave tower thereby allowing communication with one or more microwave networks. Similar to the Internet I/F described above, the microwave tower I/F may be viewed as being a base station device for the WLAN that allows any one of the WLAN interactive devices to access the one or more microwave networks via the microwave tower. Moreover, the WLAN may include a satellite earth station I/F that allows for interfacing to a satellite earth station thereby allowing communication with one or more satellite networks. The satellite earth station I/F may be viewed as being a base station device for the WLAN that allows any one of the WLAN interactive devices to access the one or more satellite networks via the satellite earth station I/F. This finite listing of various network types that may interface to the WLAN is also not intended to be exhaustive. For example, any other network may communicatively couple to the WLAN via an appropriate I/F that includes the functionality for any one of the WLAN interactive devices to access the other network. Any of the various WLAN interactive devices described within this embodiment may include an encoder and a decoder to allow bi-directional communication with the other WLAN interactive device and/or the WANs. Again, as within other embodiments that includes bi-directional communication devices having an encoder and a decoder, the encoder of any of these various WLAN interactive devices may be implemented to encode information (using its corresponding encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel that couples to another WLAN interactive device. The decoder of any of the various WLAN interactive devices may be implemented to decode the transmitted signal (using its corresponding decoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. In general, any one of the WLAN interactive devices may be characterized as being an IEEE (Institute of Electrical & Electronics Engineers) 802.11 operable device. For example, such an IEEE 802.11 operable device may be an IEEE 802.11a operable device, an IEEE 802.11b operable device, or an IEEE 802.11g operable device. Sometimes, an IEEE 802.11 operable device is operable to communicate according to more than one of the standards (e.g., both IEEE 802.11a and IEEE 802.11g in one instance). The IEEE 802.11g specification extends the rates for packet transmission in the 2.4 GHz (Giga-Hertz) frequency band. This is achieved by allowing packets, also known as frames, of two distinct types to coexist in this band. Frames utilizing DSSS/CCK (Direct Sequence Spread Spectrum with Complementary Code Keying) have been specified for transmission in the 2.4 GHz band at rates up to 11 Mbps (Mega-bits per second) as part of the IEEE 802.11b standard. The IEEE 802.11a standard uses a different frame format with OFDM (Orthogonal Frequency Division Multiplexing) to transmit at rates up to 54 Mbps with carrier frequencies in the 5 GHz range. The IEEE 802.11g specification allows for such OFDM frames to coexist with DSSS/CCK frames at 2.4 GHz. FIG. 13 is a diagram illustrating an embodiment of a DSL (Digital Subscriber Line) communication system that may be implemented according to the invention. The DSL communication system includes an interfacing to the Internet (or some other WAN). In this diagram, the Internet itself is shown, but other WANs may also be employed without departing from the scope and spirit of the invention. An ISP (Internet Service Provider) is operable to communicate data to and from the Internet. The ISP communicatively couples to a CO (Central Office) that is typically operated by a telephone services company. The CO may also allow for the providing of telephone services to one or more subscribers. However, the CO may also be implemented to allow interfacing of Internet traffic to and from one or more users (whose interactive devices are shown as user devices). These user devices may be any device within a wide variety of devices including desk-top computers, laptop computers, servers, and/or hand held devices without departing from the scope and spirit of the invention. Any of these user devices may be wired or wireless type devices as well. Each of the user devices is operably coupled to the CO via a DSL modem. The DSL modem may also be communicatively coupled to a multiple user access point or hub to allow more than one user device to access the Internet. The CO and the various DSL modems may also be implemented to include an encoder and a decoder to allow bi-directional communication therein. For example, the CO is operable to encode and decode data when communicating to and from the various DSL modems and the ISP. Similarly, each of the various DSL modems is operable to encode and decode data when communicating to and from the CO and its respective one or more user devices. As within other embodiments that employ an encoder and a decoder, the encoder of any of the CO and the various DSL modems may be implemented to encode information (using its corresponding encoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling the CO and the various DSL modems. The decoder of any of the CO and the various DSL modems may be implemented to decode the transmitted signal (using its corresponding decoder) in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 14 is a system diagram illustrating an embodiment of a fiber-optic communication system that is built according to the invention. The fiber-optic communication system includes a DWDM (Dense Wavelength Division Multiplexing, within the context of fiber optic communications) line card that is interposed between a line side and a client side. DWDM is a technology that has gained increasing interest recently. From both technical and economic perspectives, the ability to provide potentially unlimited transmission capacity is the most obvious advantage of DWDM technology. The current investment already made within fiber-optic infrastructure can not only be preserved when using DWDM, but it may even be optimized by a factor of at least 32. As demands change, more capacity can be added, either by simple equipment upgrades or by increasing the number of wavelengths (lambdas) on the fiber-optic cabling itself, without expensive upgrades. Capacity can be obtained for the cost of the equipment, and existing fiber plant investment is retained. From the bandwidth perspective, some of the most compelling technical advantages of DWDM can be summarized as follows: 1. The transparency of DWDM: Because DWDM is a PHY (PHYsical layer) architecture, it can transparently support both TDM (Time Division Multiplexing) and data formats such as ATM (Asynchronous Transfer Mode), Gigabit Ethernet, ESCON (Enterprise System CONnection), and Fibre Channel with open interfaces over a common physical layer. 2. The scalability of DWDM: DWDM can leverage the abundance of dark fiber in many metropolitan area and enterprise networks to quickly meet demand for capacity on point-to-point links and on spans of existing SONET/SDH (Synchronous Optical NETwork)/(Synchronous Digital Hierarchy) rings. 3. The dynamic provisioning capabilities of DWDM: the fast, simple, and dynamic provisioning of network connections give providers the ability to provide high-bandwidth services in days rather than months. Fiber-optic interfacing is employed at each of the client and line sides of the DWDM line card. The DWDM line card includes a transport processor that includes functionality to support DWDM long haul transport, DWDM metro transport, next-generation SONET/SDH multiplexers, digital cross-connects, and fiber-optic terminators and test equipment. On the line side, the DWDM line card includes a transmitter, that is operable to perform electrical to optical conversion for interfacing to an optical medium, and a receiver, that is operable to perform optical to electrical conversion for interfacing from the optical medium. On the client side, the DWDM line card includes a 10 G serial module that is operable to communicate with any other devices on the client side of the fiber-optic communication system using a fiber-optic interface. Alternatively, the interface may be implemented using non-fiber-optic media, including copper cabling and/or some other type of interface medium. The DWDM transport processor of the DWDM line card includes a decoder that is used to decode received signals from either one or both of the line and client sides and an encoder that is used to encode signals to be transmitted to either one or both of the line and client sides. As within other embodiments that employ an encoder and a decoder, the encoder is operable to encode information in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel to which the DWDM line card is coupled. The decoder is operable to decode a signal received from the communication channel in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. FIG. 15 is a system diagram illustrating an embodiment of a satellite receiver STB (Set Top Box) system that is built according to the invention. The satellite receiver STB system includes an advanced modulation satellite receiver that is implemented in an all digital architecture. Moreover, the advanced modulation satellite receiver may be implemented within a single integrated circuit in some embodiments. The satellite receiver STB system includes a satellite tuner that receives a signal via the L-band (e.g., within the frequency range between 390-1550 MHz (Mega-Hertz) in the ultrahigh radio frequency range). The satellite tuner extracts I, Q (In-phase, Quadrature) components from a signal received from the L-band and provides them to the advanced modulation satellite receiver. The advanced modulation satellite receiver includes a decoder. As within other embodiments that employ a decoder, the decoder is operable to decode a signal received from a communication channel to which the advanced modulation satellite receiver is coupled in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. The advanced modulation satellite receiver may be implemented to communicatively couple to an HDTV MPEG-2 (Motion Picture Expert Group, level 2) transport de-mux, audio/video decoder and display engine. The advanced modulation satellite receiver and the HDTV MPEG-2 transport de-mux, audio/video decoder and display engine communicatively couple to a host CPU (Central Processing Unit). The HDTV MPEG-2 transport de-mux, audio/video decoder and display engine also communicatively couples to a memory module and a conditional access functional block. The HDTV MPEG-2 transport de-mux, audio/video decoder and display engine provides HD (High Definition) video and audio output that may be provided to an HDTV display. The advanced modulation satellite receiver may be implemented as a single-chip digital satellite receiver supporting the decoder that operates in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. The advanced modulation satellite receiver is operable to receive communication provided to it from a transmitter device that includes an encoder as well. FIG. 16 is a schematic block diagram illustrating a communication system that includes a plurality of base stations and/or access points, a plurality of wireless communication devices and a network hardware component in accordance with certain aspects of the invention. The wireless communication devices may be laptop host computers, PDA (Personal Digital Assistant) hosts, PC (Personal Computer) hosts and/or cellular telephone hosts. The details of any one of these wireless communication devices is described in greater detail with reference to FIG. 17 below. The BSs (Base Stations) or APs (Access Points) are operably coupled to the network hardware via the respective LAN (Local Area Network) connections. The network hardware, which may be a router, switch, bridge, modem, system controller, et cetera, provides a WAN (Wide Area Network) connection for the communication system. Each of the BSs or APs has an associated antenna or antenna array to communicate with the wireless communication devices in its area. Typically, the wireless communication devices register with a particular BS or AP to receive services from the communication system. For direct connections (i.e., point-to-point communications), wireless communication devices communicate directly via an allocated channel. Typically, BSs are used for cellular telephone systems and like-type systems, while APs are used for in-home or in-building wireless networks. Regardless of the particular type of communication system, each wireless communication device includes a built-in radio and/or is coupled to a radio. The radio includes a highly linear amplifier and/or programmable multi-stage amplifier to enhance performance, reduce costs, reduce size, and/or enhance broadband applications. FIG. 17 is a schematic block diagram illustrating a wireless communication device that includes the host device and an associated radio in accordance with certain aspects of the invention. For cellular telephone hosts, the radio is a built-in component. For PDA (Personal Digital Assistant) hosts, laptop hosts, and/or personal computer hosts, the radio may be built-in or an externally coupled component. As illustrated, the host device includes a processing module, memory, radio interface, input interface and output interface. The processing module and memory execute the corresponding instructions that are typically done by the host device. For example, for a cellular telephone host device, the processing module performs the corresponding communication functions in accordance with a particular cellular telephone standard or protocol. The radio interface allows data to be received from and sent to the radio. For data received from the radio (e.g., inbound data), the radio interface provides the data to the processing module for further processing and/or routing to the output interface. The output interface provides connectivity to an output display device such as a display, monitor, speakers, et cetera, such that the received data may be displayed or appropriately used. The radio interface also provides data from the processing module to the radio. The processing module may receive the outbound data from an input device such as a keyboard, keypad, microphone, et cetera, via the input interface or generate the data itself. For data received via the input interface, the processing module may perform a corresponding host function on the data and/or route it to the radio via the radio interface. The radio includes a host interface, a digital receiver processing module, an ADC (Analog to Digital Converter), a filtering/gain module, an IF (Intermediate Frequency) mixing down conversion stage, a receiver filter, an LNA (Low Noise Amplifier), a transmitter/receiver switch, a local oscillation module, memory, a digital transmitter processing module, a DAC (Digital to Analog Converter), a filtering/gain module, an IF mixing up conversion stage, a PA (Power Amplifier), a transmitter filter module, and an antenna. The antenna may be a single antenna that is shared by the transmit and the receive paths as regulated by the Tx/Rx (Transmit/Receive) switch, or may include separate antennas for the transmit path and receive path. The antenna implementation will depend on the particular standard to which the wireless communication device is compliant. The digital receiver processing module and the digital transmitter processing module, in combination with operational instructions stored in memory, execute digital receiver functions and digital transmitter functions, respectively. The digital receiver functions include, but are not limited to, digital IF (Intermediate Frequency) to baseband conversion, demodulation, constellation de-mapping, decoding, and/or descrambling. The digital transmitter functions include, but are not limited to, scrambling, encoding, constellation mapping, modulation, and/or digital baseband to IF conversion. Similarly to other embodiments that employ an encoder and a decoder (or perform encoding and decoding), the encoding operations that may be performed by the digital transmitter processing module may be implemented in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling to the wireless communication device. Analogously, the decoding operations of the operations that may be performed by the digital transmitter processing module may be implemented in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. For example, the encoding operations performed by the digital transmitter processing module may be performed using LDPC coding as described and presented herein, and the decoding operations that may be performed by the digital receiver processing module may be performed using the simultaneous and parallel approach to updating of edge messages. The digital receiver and transmitter processing modules may be implemented using a shared processing device, individual processing devices, or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, DSP (Digital Signal Processor), microcomputer, CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on operational instructions. The memory may be a single memory device or a plurality of memory devices. Such a memory device may be a ROM (Read Only Memory), RAM (Random Access Memory), volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, and/or any device that stores digital information. It is noted that when either of the digital receiver processing module or the digital transmitter processing module implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory storing the corresponding operational instructions is embedded with the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. In operation, the radio receives outbound data from the host device via the host interface. The host interface routes the outbound data to the digital transmitter processing module, which processes the outbound data in accordance with a particular wireless communication standard (e.g., IEEE 802.11, Bluetooth®, et cetera) to produce digital transmission formatted data. The digital transmission formatted data is a digital base-band signal or a digital low IF signal, where the low IF typically will be in the frequency range of one hundred kHz (kilo-Hertz) to a few MHz (Mega-Hertz). The DAC converts the digital transmission formatted data from the digital domain to the analog domain. The filtering/gain module filters and/or adjusts the gain of the analog signal prior to providing it to the IF mixing stage. The IF mixing stage converts the analog baseband or low IF signal into an RF signal based on a transmitter local oscillation provided by local oscillation module. The PA amplifies the RF signal to produce outbound RF signal, which is filtered by the transmitter filter module. The antenna transmits the outbound RF signal to a targeted device such as a base station, an access point and/or another wireless communication device. The radio also receives an inbound RF signal via the antenna, which was transmitted by a BS, an AP, or another wireless communication device. The antenna provides the inbound RF signal to the receiver filter module via the Tx/Rx switch, where the Rx filter bandpass filters the inbound RF signal. The Rx filter provides the filtered RF signal to the LNA, which amplifies the signal to produce an amplified inbound RF signal. The LNA provides the amplified inbound RF signal to the IF mixing module, which directly converts the amplified inbound RF signal into an inbound low IF signal or baseband signal based on a receiver local oscillation provided by local oscillation module. The down conversion module provides the inbound low IF signal or baseband signal to the filtering/gain module. The filtering/gain module filters and/or gains the inbound low IF signal or the inbound baseband signal to produce a filtered inbound signal. The ADC converts the filtered inbound signal from the analog domain to the digital domain to produce digital reception formatted data. In other words, the ADC samples the incoming continuous time signal thereby generating a discrete time signal (e.g., the digital reception formatted data). The digital receiver processing module decodes, descrambles, demaps, and/or demodulates the digital reception formatted data to recapture inbound data in accordance with the particular wireless communication standard being implemented by radio. The host interface provides the recaptured inbound data to the host device via the radio interface. As one of average skill in the art will appreciate, the wireless communication device of FIG. 17 may be implemented using one or more integrated circuits. For example, the host device may be implemented on one integrated circuit, the digital receiver processing module, the digital transmitter processing module and memory may be implemented on a second integrated circuit, and the remaining components of the radio, less the antenna, may be implemented on a third integrated circuit. As an alternate example, the radio may be implemented on a single integrated circuit. As yet another example, the processing module of the host device and the digital receiver and transmitter processing modules may be a common processing device implemented on a single integrated circuit. Further, the memories of the host device and the radio may also be implemented on a single integrated circuit and/or on the same integrated circuit as the common processing modules of processing module of the host device and the digital receiver and transmitter processing module of the radio. FIG. 18 is a diagram illustrating an alternative embodiment of a wireless communication device that is constructed according to the invention. This embodiment of a wireless communication device includes an antenna that is operable to communicate with any 1 or more other wireless communication devices. An antenna interface communicatively couples a signal to be transmitted from the wireless communication device or a signal received by the wireless communication device to the appropriate path (be it the transmit path or the receive path). A radio front end includes receiver functionality and transmitter functionality. The radio front end communicatively couples to an analog/digital conversion functional block. The radio front end communicatively couples to a modulator/demodulator, and the radio front end communicatively couples to a channel encoder/decoder. Along the Receive Path: The receiver functionality of the front end includes a LNA (Low Noise Amplifier)/filter. The filtering performed in this receiver functionality may be viewed as the filtering that is limiting to the performance of the device, as also described above. The receiver functionality of the front end performs any down-converting that may be requiring (which may alternatively include down-converting directly from the received signal frequency to a baseband signal frequency). The general operation of the front end may be viewed as receiving a continuous time signal, and performing appropriate filtering and any down conversion necessary to generate the baseband signal. Whichever manner of down conversion is employed, a baseband signal is output from the receiver functionality of the front end and provided to an ADC (Analog to Digital Converter) that samples the baseband signal (which is also a continuous time signal, though at the baseband frequency) and generates a discrete time signal baseband signal (e.g., a digital format of the baseband signal); the ADC also extracts and outputs the digital I, Q (In-phase, Quadrature) components of the discrete time signal baseband signal. These I, Q components are provided to a demodulator portion of the modulator/demodulator where any modulation decoding/symbol mapping is performed where the I, Q components of the discrete time signal baseband signal. The appropriate I, Q components are then mapped to an appropriate modulation (that includes a constellation and corresponding mapping). Examples of such modulations may include BPSK (Binary Phase Shift Key), QPSK (Quadrature Phase Shift Key), 8 PSK (8 Phase Shift Key), 16 QAM (16 Quadrature Amplitude Modulation), and even higher order modulation types. These demodulated symbols are then provided to a decoder portion of the channel encoder/decoder where best estimates of the information bits contained within the originally received continuous time signal are made. Along the Transmit Path: Somewhat analogous and opposite processing is performed in the transmit path when compared to the receive path. Information bits that are to be transmitted are encoded using an encoder of the channel encoder/decoder. These encoded bits are provided to a modulator of the modulator/demodulator where modulation encoding/symbol mapping may be performed according to the modulation of interest. These now I, Q components of the symbols are then passed to a DAC (Digital to Analog Converter) of the analog/digital conversion functional block to transform the I, Q components into a continuous time transmit signal (e.g., an analog signal). The now continuous time transmit signal to be transmitted is then passed to a transmit driver that performs any necessary up-converting/modification to the continuous time transmit signal (e.g., amplification and/or filtering) to comport it to the communication channel over which the signal is to be transmitted to another device via the antenna. As within other embodiments that employ an encoder and a decoder, the encoder of this wireless communication device may be implemented to encode information in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention to assist in generating a signal that is to be launched into the communication channel coupling to the wireless communication device. The decoder of the wireless communication device may be implemented to decode a received signal in a manner in accordance with the functionality and/or processing of at least some of the various aspects of the invention. This diagram shows yet another embodiment where one or more of the various aspects of the invention may be found. In addition, several of the following Figures describe particular embodiments (in more detail) that may be used to implement some of the various aspects of invention that include LDPC decoding that performs updating of edge messages using only multiplication (or log domain addition) on both sides of LDPC bipartite graph. Several details of these various aspects are provided below. Initially, a general description of LDPC codes is provided. FIG. 19 is a diagram illustrating an embodiment of an LDPC (Low Density Parity Check) code bipartite graph. An LDPC code may be viewed as being a code having a binary parity check matrix such that nearly all of the elements of the matrix have values of zeros (e.g., the binary parity check matrix is sparse). For example, H=(hi,j)M×N may be viewed as being a parity check matrix of an LDPC code with block length N. The number of I's in the i-th column of the parity check matrix may be denoted as dv(i), and the number of 1's in the j-th row of the parity check matrix may be denoted as dc(j). If dv(i)=dv for all i, and dc(j)=dc for all j, then the LDPC code is called a (dv,dc) regular LDPC code, otherwise the LDPC code is called an irregular LDPC code. LDPC codes were introduced by R. Gallager in [1] referenced above and by M. Lugy et al. in [2] also referenced above. A regular LDPC code can be represented as a bipartite graph by its parity check matrix with left side nodes representing variable of the code bits, and the right side nodes representing check equations. The bipartite graph of the code defined by H may be defined by N variable nodes (e.g., N bit nodes) and M check nodes. Every variable node of the N variable nodes has exactly dv(i) edges connecting this node to one or more of the check nodes (within the M check nodes). This number of dv edges may be referred to as the degree of a variable node i. Analogously, every check node of the M check nodes has exactly dc(j) edges connecting this node to one or more of the variable nodes. This number of dc edges may be referred to as the degree of the check node j. An edge between a variable node vi (or bit node bi) and check node cj may be defined by e=(i, j). However, on the other hand, given an edge e=(i, j), the nodes of the edge may alternatively be denoted as by e=(v(e),c(e)) (or e=(b(e),c(e))). Given a variable node vi (or bit node bi), one may define the set of edges emitting from the node vi (or bit node bi) by Ev(i)={e|v(e)=i} (or by Eh(i)={e|b(e)=i}). Given a check node cj, one may define the set of edges emitting from the node cj by Ec(j)={e|c(e)=j}. Continuing on, the derivative result will be |Ev(i)=dv (or |Eh(i)|=dh) and |Ec(j)|=dc. Generally speaking, any codes that can be represented by a bipartite graph may be characterized as graph codes. The reader is referred to the DESCRIPTION OF RELATED ART section above that described the SPA approach by which LDPC coded signals are conventionally decoded. It is also noted that an irregular LDPC code may also described using a bipartite graph. However, the degree of each set of nodes within an irregular LDPC code may be chosen according to some distribution. Therefore, for two different variable nodes, vi1 and vi2, of an irregular LDPC code, |Ev(i1)| may not equal to |Ev(i2)|. This relationship may also hold true for two check nodes. The concept of irregular LDPC codes was originally introduced within M. Lugy et al. in [2] referenced above. In general, with a graph of an LDPC code, the parameters of an LDPC code can be defined by a degree of distribution, as described within M. Lugy et al. in [2] referenced above and also within the following reference: [5] T. J. Richardson and R. L. Urbanke, “The capacity of low-density parity-check code under message-passing decoding,” IEEE Trans. Inform. Theory, Vol. 47, pp. 599-618, February 2001. This distribution may be described as follows: Let λi represent the fraction of edges emanating from variable nodes of degree i and let ρi represent the fraction of edges emanating from check nodes of degree i. Then, a degree distribution pair (λ, ρ) is defined as follows: λ ( x ) = ∑ i = 2 M v λ i x i - 1 and ρ ( x ) = ∑ i = 2 M c ρ i x i - 1 , where Mv and Mc represent the maximal degrees for variable nodes and check nodes, respectively. While many of the illustrative embodiments described herein utilize regular LDPC code examples, it is noted that the invention is also operable to accommodate both regular LDPC codes and irregular LDPC codes. The LLR (Log-Likelihood Ratio) decoding of LDPC codes may be described as follows: the probability that a bit within a received vector in fact has a value of 1 when a 1 was actually transmitted is calculated. Similarly, the probability that a bit within a received vector in fact has a value of 0 when a 0 was actually transmitted is calculated. These probabilities are calculated using the LDPC code that is use to check the parity of the received vector. The LLR is the logarithm of the ratio of these two calculated probabilities. This LLR will give a measure of the degree to which the communication channel over which a signal is transmitted may undesirably affect the bits within the vector. The LLR decoding of LDPC codes may be described mathematically as follows: Beginning with C={v|v=(v0, . . . ,vN−1),vHT=0} being an LDPC code and viewing a received vector, y=(y0, . . . ,yN−1), with the sent signal having the form of ((−1)v0i, . . . ,(−1)vN−1), then the metrics of the channel may be defined as p(yi|vi=0), p(yi|vi=1), i=0, . . . ,N−1. The LLR of a metric will then be defined as follows: L metric ( i ) = ln p ( y i ❘ v i = 0 ) p ( y i ❘ v i = 1 ) For every variable node vi, its LLR information value will then be defined as follows: ln p ( v i = 0 ❘ y i ) p ( v i = 1 ❘ y i ) = L metric ( i ) + ln p ( v i = 0 ) p ( v i = 1 ) Since the variable node, vi, is in a codeword, then the value of the ratio of these, ln p ( v i = 0 ) p ( v i = 1 ) , may be replaced by the following ln ln p ( v i = 0 , v H T = 0 ❘ y ) p ( v i = 1 , v H T = 0 ❘ y ) = ∑ ( i , j ) ∈ E v ( i ) ln p ( v i = 0 , v h j T = 0 ❘ y ) p ( v i = 1 , v h j T = 0 ❘ y ) where Ev(i) is a set of edges starting with vi as defined above. When performing the BP (Belief Propagation) decoding approach in this context, then the value of ln ln p ( v i = 0 , v h j T = 0 ❘ y ) p ( v i = 1 , v h j T = 0 ❘ y ) may be replaced by the following relationship L check ( i , j ) = ln p ( ∑ e ∈ E c ( j ) ∖ { ( i , j ) } v v ( e ) = 0 ❘ y ) p ( ∑ e ∈ E c ( j ) ∖ { ( i , j ) } v v ( e ) = 1 ❘ y ) = Lcheck(i, j) is called the EXT (extrinsic) information of the check node cj with respect to the edge (i, j). In addition, it is noted that e∈Ec(j)\{(i, j)} indicates all of the edges emitting from check node cj except for the edge that emits from the check node cj to the variable node vi. Extrinsic information values may be viewed as those values that are calculated to assist in the generation of best estimates of actual bit values within a received vector. Also in a BP approach, then the extrinsic information of the variable node vi with respect to the edge (i, j) may be defined as follows: L var ( i , j ) = L metric ( i ) + ∑ ( i , k ) ∈ E v ( i ) ∖ { ( i , j ) } L check ( i , k ) . From certain perspectives, the invention may also be implemented within communication systems that involve combining modulation coding with LDPC coding to generate LDPC coded modulation signals. These LDPC coded modulation signals may be such that they have a code rate and/or modulation (constellation and mapping) that varies as frequently as on a symbol by symbol basis. FIG. 20 is a diagram illustrating an embodiment of LDPC (Low Density Parity Check) decoding functionality using bit metric according to the invention. To perform decoding of an LDPC coded signal having an m-bit signal sequence, the functionality of this diagram may be employed. After receiving the I, Q (In-phase, Quadrature) values of a signal at the symbol nodes, an m-bit symbol metric computer functional block calculates the corresponding symbol metrics. At the symbol nodes, these symbol metrics are then passed to a symbol node calculator functional block that uses these received symbol metrics to calculate the bit metrics corresponding to those symbols. These bit metrics are then passed to the bit nodes connected to the symbol nodes. Thereafter, at the bit nodes, a bit node calculator functional block operates to compute the corresponding soft messages of the bits. Then, in accordance with iterative decoding processing, the bit node calculator functional block receives the edge messages from a check node operator functional block and updates the edge messages with the bit metrics received from the symbol node calculator functional block. These edge messages, after being updated, are then passed to the check node operator functional block. At the check nodes, the check node operator functional block then receives these edge messages sent from the bit nodes (from the bit node calculator functional block) and updates them accordingly. These updated edge messages are then passed back to the bit nodes (e.g., to the bit node calculator functional block) where the soft information of the bits is calculated using the bit metrics and the current iteration values of the edge messages. Thereafter, using this just calculated soft information of the bits (shown as the soft message), the bit node calculator functional block updates the edge messages using the previous values of the edge messages (from the just previous iteration) and the just calculated soft message. The iterative processing continues between the bit nodes and the check nodes according to the LDPC code bipartite graph that was employed to encode the signal that is being decoded. These iterative decoding processing steps, performed by the bit node calculator functional block and the check node operator functional block, are repeated a predetermined number of iterations (e.g., repeated n times, where n is selectable). Alternatively, these iterative decoding processing steps are repeated until the syndromes of the LDPC code are all equal to zero (within a certain degree of precision). Soft output information is generated within the bit node calculator functional block during each of the decoding iterations. In this embodiment, this soft output may be provided to a hard limiter where hard decisions may be made, and that hard information may be provided to a syndrome calculator to determined whether the syndromes of the LDPC code are all equal to zero (within a certain degree of precision). That is to say, the syndrome calculator determines whether each syndrome associated with the LDPC code is substantially equal to zero as defined by some predetermined degree of precision. For example, when a syndrome has a mathematically non-zero value that is less than some threshold as defined by the predetermined degree of precision, then that syndrome is deemed to be substantially equal to zero. When a syndrome has a mathematically non-zero value that is greater than the threshold as defined by the predetermined degree of precision, then that syndrome is deemed to be substantially not equal to zero. When the syndromes are not substantially equal to zero, the iterative decoding processing continues again by appropriately updating and passing the edge messages between the bit node calculator functional block and the check node operator functional block. After all of these iterative decoding processing steps have been performed, then the best estimates of the bits are output based on the bit soft information. In the approach of this embodiment, the bit metric values that are calculated by the symbol node calculator functional block are fixed values and used repeatedly in updating the bit node values. FIG. 21 is a diagram illustrating an alternative embodiment of LDPC decoding functionality using bit metric according to the invention (when performing n number of iterations). This embodiment shows how the iterative decoding processing may be performed when a predetermined number of decoding iterations, shown as n, is performed. If the number of decoding iterations is known beforehand, as in a predetermined number of decoding iterations embodiment, then the bit node calculator functional block may perform the updating of its corresponding edge messages using the bit metrics themselves (and not the soft information of the bits as shown in the previous embodiment and described above). This processing may be performed in all but a final iterative decoding iteration (e.g., for iterations 1 through n−1). However, during the final iteration, the bit node calculator functional block calculated the soft information of the bits (shown as soft output). The soft output is then provided to a hard limiter where hard decisions may be made of the bits. The syndromes need not be calculated in this embodiment since only a predetermined number of decoding iterations are being performed. FIG. 22 is a diagram illustrating an alternative embodiment of LDPC (Low Density Parity Check) decoding functionality using bit metric (with bit metric updating) according to the invention. To perform decoding of an LDPC coded signal having an m-bit signal sequence, the functionality of this diagram may be employed. After receiving the I, Q (In-phase, Quadrature) values of a signal at the symbol nodes, an m-bit symbol metric computer functional block calculates the corresponding symbol metrics. At the symbol nodes, these symbol metrics are then passed to a symbol node calculator functional block that uses these received symbol metrics to calculate the bit metrics corresponding to those symbols. These bit metrics are then passed to the bit nodes connected to the symbol nodes. The symbol node calculator functional block is also operable to perform bit metric updating during subsequent decoding iterations. Thereafter, at the bit nodes, a bit node calculator functional block operates to compute the corresponding soft messages of the bits. Then, in accordance with iterative decoding processing, the bit node calculator functional block receives the edge messages from a check node operator functional block and updates the edge messages with the bit metrics received from the symbol node calculator functional block. This updating of the edge messages may be performed using the updated bit metrics during subsequent iterations. These edge messages, after being updated, are then passed to the check node operator functional block. At the check nodes, the check node operator functional block then receives these edge messages sent from the bit nodes (from the bit node calculator functional block) and updates them accordingly. These updated edge messages are then passed back to the bit nodes (e.g., to the bit node calculator functional block) where the soft information of the bits is calculated using the bit metrics and the current iteration values of the edge messages. Thereafter, using this just calculated soft information of the bits (shown as the soft message), the bit node calculator functional block updates the edge messages using the previous values of the edge messages (from the just previous iteration) and the just calculated soft message. At the same time, as the just calculated soft information of the bits (shown as the soft message) has been calculated, this information may be passed back to the symbol nodes (e.g., to the symbol node calculator functional block) for updating of the bit metrics employed within subsequent decoding iterations. The iterative processing continues between the bit nodes and the check nodes according to the LDPC code bipartite graph that was employed to encode the signal that is being decoded (by also employing the updated bit metrics during subsequent decoding iterations). These iterative decoding processing steps, performed by the bit node calculator functional block and the check node operator functional block, are repeated a predetermined number of iterations (e.g., repeated n times, where n is selectable). Alternatively, these iterative decoding processing steps are repeated until the syndromes of the LDPC code are all equal to zero (within a certain degree of precision). Soft output information is generated within the bit node calculator functional block during each of the decoding iterations. In this embodiment, this soft output may be provided to a hard limiter where hard decisions may be made, and that hard information may be provided to a syndrome calculator to determined whether the syndromes of the LDPC code are all equal to zero (within a certain degree of precision). When they are not, the iterative decoding processing continues again by appropriately updating and passing the edge messages between the bit node calculator functional block and the check node operator functional block. After all of these iterative decoding processing steps have been performed, then the best estimates of the bits are output based on the bit soft information. In the approach of this embodiment, the bit metric values that are calculated by the symbol node calculator functional block are fixed values and used repeatedly in updating the bit node values. FIG. 23 is a diagram illustrating an alternative embodiment of LDPC decoding functionality using bit metric (with bit metric updating) according to the invention (when performing n number of iterations). This embodiment shows how the iterative decoding processing may be performed when a predetermined number of decoding iterations, shown as n, is performed (again, when employing bit metric updating). If the number of decoding iterations is known beforehand, as in a predetermined number of decoding iterations embodiment, then the bit node calculator functional block may perform the updating of its corresponding edge messages using the bit metrics/updated bit metrics themselves (and not the soft information of the bits as shown in the previous embodiment and described above). This processing may be performed in all but a final decoding iteration (e.g., for iterations 1 through n−1). However, during the final iteration, the bit node calculator functional block calculated the soft information of the bits (shown as soft output). The soft output is then provided to a hard limiter where hard decisions may be made of the bits. The syndromes need not be calculated in this embodiment since only a predetermined number of decoding iterations are being performed. FIG. 24A is a diagram illustrating bit decoding using bit metric (shown with respect to an LDPC (Low Density Parity Check) code bipartite graph) according to the invention. Generally speaking, after receiving I, Q values of a signal at a symbol nodes, the m-bit symbol metrics are computed. Then, at the symbol nodes, the symbol metric is used to calculate the bit metric. The bit metric is then passed to the bit nodes connected to the symbol nodes. At the bit nodes, the soft messages of the bits are computed, and they are used to update the edge message sent from the check nodes with the bit metric. These edge messages are then passed to the check nodes. At the check nodes, updating of the edge messages sent from the bit nodes is performed, and these values are pass back the bit nodes. As also described above with respect to the corresponding functionality embodiment, after all of these iterative decoding processing steps have been performed, then the best estimates of the bits are output based on the bit soft information. In the approach of this embodiment, the bit metric values that are calculated by the symbol node calculator functional block are fixed values and used repeatedly in updating the bit node values. FIG. 24B is a diagram illustrating bit decoding using bit metric updating (shown with respect to an LDPC (Low Density Parity Check) code bipartite graph) according to the invention. With respect to this LDPC code bipartite graph that performs bit metric updating, the decoding processing may be performed as follows: After receiving the I, Q value of the signal at the symbol nodes, the m-bit symbol metrics are computed. Then, at the symbol nodes, the symbol metrics are used to calculate the bit metrics. These values are then passed to the bit nodes connected to the symbol nodes. At the bit nodes, the edge message sent from the check nodes are updated with the bit metrics, and these edge messages are passed to the check nodes. In addition, at the same time the soft bit information is updated and passed back to the symbol nodes. At the symbol nodes, the bit metrics are updated with the soft bit information sent from the bit nodes, and these values are passed back to the variable nodes. At the check nodes, the edge information sent from the bit nodes is updated, and this information is passed back to the bit nodes. As also described above with respect to the corresponding functionality embodiment, after all of these iterative decoding processing steps have been performed, then the best estimates of the bits are output based on the bit soft information. Again, it is shown in this embodiment that the bit metric values are not fixed; they are updated for use within subsequent decoding iterations. This is again in contradistinction to the embodiment described above where the bit metric values that are calculated only once and remain fixed values for all of the decoding iterations. FIG. 25 is a diagram illustrating an embodiment of check node and bit node estimation functionality (employing likelihood decoding at check node side) according to the invention. This embodiment shows the functionality employed when estimating the bit node and estimating the check node within the LDPC decoding processing employed according likelihood decoding in accordance with the invention. The check node estimate is initially described below. This description begins by considering a check node i. The set of edges connecting from this check node i to its corresponding bit nodes may be denoted as Ec(j)={(ik,j)k=0, . . . ,n−1} .A codeword that is to be decoded may be represented as b=(b0, . . . ,bN−1). Then, by the definition of the parity check according to the LDPC code, the following relationship holds true: ∑ k = 0 n - 1 b i k = 0 ( EQ 3 ) For every edge e∈Ec(j) (which may be represented as e=(i0,j) for convenience), the estimation of the check node may be calculated as follows: z e = Pr ( ∑ k = 0 n - 1 b i k = 0 ❘ b i o = 0 ) = Pr ( ∑ k = 1 n - 1 b i k = 0 ) ( EQ 4 ) Denote xk=Pr(bik=0). When n=3, without lost of generality, let x=x1 and y=x2, then ze=xy+(1−x)(1−y) (EQ 5) From (EQ 5), one can see that z is a “sum product” of the variables x and y. To transform the “sum product” calculation to being only a “product” calculation, the following map may be employed: F(x)=2x−1 (EQ 6) With this appropriately defines map, (EQ 5) is then transformed to the following: F(z)=F(x)F(y) (EQ 7) To prove (EQ 7), the following is provided: F ( z ) = 2 x y + 2 ( 1 - x ) ( 1 - y ) - 1 = 4 x y - 2 x - 2 y + 1 = ( 2 x - 1 ) ( 2 y - 1 ) = F ( x ) F ( y ) ( EQ 8 ) In general, let e=(il, j), denote z n - 1 = Pr ( ∑ k ≠ 1 , k = 0 n - 2 b i k = 0 ) , then zc=zn−1xn−1+(1−zn−1)(1−xn−1) (EQ 9) Therefore, the following is also true. F ( z e ) = F ( z n - 1 ) F ( x n - 1 ) = ∏ k ≠ 1 F ( x k ) ( EQ 10 ) With equation (EQ 10), the probability estimation of check node, F(ze), is just the product of terms function of its corresponded bit nodes probability estimations, F(xk). Here the “sum” part in the conventional decoder (e.g. that employs the SPA approach as described above) is eliminated. By using the appropriate mapping as described above, the calculations that are needed to perform updating of edge messages may be performed using only multiplication (or log domain addition). In short, the updating of the estimation of the check nodes may be implemented as a product of terms function only. Within the log domain, this may be implemented as using a sum of terms function. The bit node estimate is now described below with respect to this diagram. A bit node i is now considered. Let Eb(i)={(i, jk), k=0, . . . ,m−1} be the set of edges connected from this bit node to its corresponding check nodes. Let Sj0, . . . ,Sjm−1 be the check equations that correspond the check node j0, . . . ,jm−1. Let b=(b0, . . . ,bn−1) be a codeword, then the following probability calculation is true: Pr(b=0,b is a codeword)=Pr(bi=0,Sjk=0, k=0, . . . m−1) (EQ 11) Denote Tk=Sjk+bi (where + means binary addition). In the BP (Belief Propagation) decoding approach, the probability calculation presented above within (EQ 11) is replaced by the following calculation: x = metric ( i ) ∏ k = 0 m - 1 Pr ( T k = 0 ) ( EQ 12 ) The bit metric metric(i) is computed from the received signal. The second part of the (EQ 12) is the product of terms function of the value ze,e∈Eb(i), defined in (EQ 4) above. Since the values of F(ze), whose calculation is shown above, is passed from the check nodes, the following calculation can be made here at the bit nodes: x = metric ( i ) ∏ e ∈ E b ( i ) z e = metric ( i ) ∏ e ∈ E b ( i ) ( F ( z e ) + 1 2 ) ( EQ 13 ) However, since (EQ 12) is not exactly equivalent to (EQ 16), the following relationship is presented: 1−≠Pr (bi=1, b is a codeword) (EQ 14) In order to carry the computation on the check nodes (which is presented above with respect to this diagram), the probability of bi=0 needs to be passed to the check nodes. Two alternative approaches of generating this information are given below; they are the likelihood approach and the likelihood ratio approach. Likelihood Approach Estimate Pr(bi=1, b is a codeword) using y = ( 1 - metric ( i ) ) ∏ e ∈ E b ( i ) ( 1 - z e ) = ( 1 - metric ( i ) ) ∏ e ∈ E b ( i ) ( 1 - F ( z e ) 2 ) ( EQ 15 ) then normalize x and y to get x/(x+y) which can be considered as Pr(bi=0) in the check node estimation that is presented above. Likelihood Ratio Approach Estimate the probability ratio at the bid node, i.e. r = 1 - metric ( i ) metric ( i ) ∏ e ∈ E b ( i ) ( 1 - z e z e ) = 1 - metric ( i ) metric ( i ) ∏ e ∈ E b ( i ) ( 1 - F ( z e ) 1 + F ( z e ) ) Since r is an estimate of the ratio, Pr ( b i = 1 ) Pr ( b i = 0 ) , if x=Pr(bi=0), the following relationship holds true: F ( x ) = 2 Pr ( b i = 0 ) Pr ( b i = 1 ) + Pr ( b i = 0 ) - 1 = Pr ( b i = 0 ) - Pr ( b i = 1 ) Pr ( b i = 1 ) + Pr ( b i = 0 ) = 1 - r 1 + r therefore, F ( x ) = 1 - r 1 + r will be passed to the check nodes. Various alternatives to performing decoding processing of LDPC coded signals according to the invention are presented below with respect to the FIG. 26 and the FIG. 27. For each of these two alternative decoding approaches presented below with respect to the FIG. 26 and the FIG. 27, the decoding processing operates on a received vector that is characterized as y=(y0, . . . yn−1). FIG. 26 is a diagram illustrating an embodiment of LDPC decoding functionality (employing likelihood processing on both check nodes and bit nodes) according to the invention. This decoding processing may be viewed as being performed in 4 separate steps. Step 1. Compute the metrics meti(0),meti(1) for every position i=0, . . . n−1 using y and according to the Gaussian distribution. Each of these metric values, meti(0),meti(1), correspond to the supposed values of the received bit as being 1 and as being zero. For example, meti(0) corresponds to the value for 0, and meti(1) corresponds to the value for 1. Once each of these metric values are calculated, then the metric is normalized as follows to generate the following normalized metric, metric(i): metric ( i ) = met i ( 0 ) met i ( 0 ) + met i ( 1 ) . Step 2. For every edge e, the edge messages with respect to the bit nodes, Medgeh(e), are initialized. This is performed by using the function, F(x), that is described in more detail above and is shown mathematically as follows: Medgeb(e)=F(metric(b(e))). Step 3. This step directs how edge messages with respect to the check nodes, Medgec(e), are updated within the iterative decoding processing describe herein. For every check node j, let Ec(j) be the set of all edges connected from the check node j to its corresponding bit nodes. This step then operates to update the edge messages with respect to check nodes, Medgec(e), using only a product of terms function (or a log domain sum of terms function) that operates on the edge messages with respect to the bit nodes, Medgeh(e). During the first decoding iteration, this updating of the edge messages with respect to check nodes, Medgec(e), operates by using the initialized edge messages with respect to the bit nodes, Medgeh(e), that are initialized within the Step 2 above. Afterwards, during subsequent decoding iterations, this updating is performed using the subsequently updated edge messages with respect to the bit nodes, Medgeb(e), that have been updated as is described in more detail below with respect to Step 4. The product of terms function used to update the edge messages with respect to the check nodes, Medgec(e), using the edge messages with respect to the bit nodes, Medgeb(e), is shown mathematically below. Each edge message with respect to the check nodes, Medgec(e), is updated for every e∈Ec(j) as follows: Medge c ( e ) = ∏ f ∈ E c ( j ) ∖ { e } Medge b ( f ) ( EQ 16 ) Step 4. This step directs how edge messages with respect to the bit nodes, Medgeb(e), are updated within the iterative decoding processing describe herein. For every bit node i, let Eb(i) be the set of all edges connected from the bit node i to its corresponding check nodes. Compute the following threshold functions: P i ( 0 ) = metric ( i ) ∏ e ∈ E b ( i ) ( Medge c ( e ) + 1 2 ) , and P i ( 1 ) = ( 1 - metric ( i ) ) ∏ e ∈ E b ( i ) ( 1 - Medge c ( e ) 2 ) ( EQ 17 ) For every e∈Eb(i), compute the following functions: q 0 ( e ) = P i ( 0 ) ( Medge c ( e ) + 1 2 ) , q 1 ( e ) = P i ( 0 ) ( 1 - Medge c ( e ) 2 ) ( EQ 18 ) The edge messages with respect to the bit nodes, Medgeb(e), are updated using the previously defined function, F(x), as indicated below using the intermediate functions, q0(e) and q1(e). Medge b ( e ) = F ( q 0 ( e ) q 0 ( e ) + q 1 ( e ) ) ( EQ 19 ) If the current decoding iteration is the last decoding iteration (e.g., a final decoding iteration), then this decoding functionality operates by outputting soft information corresponding to the most recently updated edge messages with respect to the bit nodes, Medgeb(e), and making subsequent hard decisions thereon to make a best estimate of the at least one information bit contained within the originally received vector, y=(y0, . . . yn−1). It is noted that the received vector, y=(y0, . . . yn−1), is extracted from a received continuous time signal received by a communication device (after having undergone any appropriate preprocessing such as filtering, sampling, demodulation and symbol mapping, and so on). If the current decoding iteration is not in fact the last decoding iteration, then this decoding functionality operates to go back to the Step 3 indicated above. The Step 3 and the Step 4 can continue to operate alternatively to perform iterative decoding processing of updating edge messages with respect to the check nodes, Medgec(e), and updating edge messages with respect to the bit nodes, Medgeb(e), respectively. After having performed a last decoding iteration, and when hard decisions are to be made, the hard decisions (e.g., best estimates) that are output for the bit of concern are made using the above-calculated threshold functions as follows: Output best estimate for bit as bi=0 if Pi(0)≧Pi(1); Output best estimate for bit as bi=1 otherwise. These earlier calculated functions, Pi(0) and Pi(1), may be viewed as being the thresholds by which the final hard decisions are to be made with respect to the bits as being of a value of 0 and a value of 1, respectively. It is also noted the decoding functionality of this diagram may alternatively be implemented within the log domain as well without departing from the scope and spirit of the invention. This procedure is described below when converted to the log domain. To operate the LDPC decoding according to this particular aspect of the invention within the log domain, the function, ln(F(x)), which is the natural log of F(x), needs to be computed. Since the variable x is the probability, it has a range of [0,1]. Therefore, the function F(x) has a range [−1,1]. Because of this, the calculations involved within the iterative decoding processing need to deal with the logarithm of a negative number. This may be dealt with as depicted below. Define a sign function as follows: sign ( x ) = { 1 x ≥ 0 - 1 x < 0 ( EQ 20 ) According to the definition of the natural logarithm, In, if x≠0, then the following relationship is true: ln ( x ) = ( sign ( x ) - 1 ) 2 π i + ln ( x ) ( EQ 21 ) Moreover, the following relationship is also employed: exp ( k π i ) = { - 1 k is odd - 1 k is even . Then, the following relationship is also true: ln ( ∑ i = 1 n x i ) = ( ∑ i = 1 n ( sign ( x i ) - 1 2 ) ) π i + ∑ i = 1 n ln ( x i ) . ( EQ 22 ) When actually implementing the calculation of the (EQ 22) shown above, the various components may be separated into two separate parts. For example, a first part that may be calculated is the sign function that is a sum of terms function of the various sign functions, ∏ i = 1 n sign ( x i ) . A second part that may be calculated is shown as follows: ∑ i = 1 n ln ( x i ) . When implementing these calculations employed within the iterative decoding processing within the log domain (e.g., within hardware within an actual communication device that performs this LDPC decoding in accordance with these aspects of the invention), the above-provided (EQ 16) may also be separated into two separate parts as well, namely, A and B provided below. That is to say, the total calculation of the (EQ 16) shown above may be replaced by the following two parts. A = ∏ f ∈ E c ( j ) ∖ { e } sign ( Medge b ( f ) ) , and B = ∑ f ∈ Ec ( j ) ∖ { e } ln ( Medge b ( f ) ) . A may be viewed as being a product of terms function of the sign functions of the appropriate edge messages with respect to the bit nodes, Medgeb(e); and B may be viewed as being a sum of terms function of the natural log functions of the appropriate edge messages with respect to the bit nodes, Medgeb(e). Therefore, the actual calculations to perform the updating of the edge messages with respect to the check nodes, Medgec(e), may be a very straight-forward calculation of these two intermediate values A and B as shown below. Medgec(e)=A exp (B). Since the function, F(x), has the range [ - 1 , 1 ] , F ( x ) + 1 2 , has the range [0,1]. Thus the logarithm conversion of the (EQs 17-19) shown above can be carried out over positive values. An alternative approach to supporting LDPC decoding functionality according to the invention may be provided using the employing the LR (Likelihood Ratio) processing on the bit nodes. FIG. 27 is a diagram illustrating an embodiment of LDPC decoding functionality (employing LR (Likelihood Ratio) processing on bit nodes) implemented in log domain according to the invention. Somewhat analogously to the embodiment described above, the decoding processing of this embodiment may also be viewed as being performed in 4 separate steps. Only the log domain version by which this decoding functionality may be implemented is presented below. Of course, a non-log domain version could also be implemented without departing from the scope and spirit of the invention. Step 1. the LLR (Log-Likelihood Ratio) metric is calculated as shown below: met(i)=ln(metrici(1)/metrici(0)) This is performed for every position i=0, . . . ,n−1 using the received vector y (e.g., y=(y0, . . . yn−1)) and according to the Gaussian distribution. Step 2. For every edge e, the corresponding edge messages with respect to the bit nodes, Medgeb(e), are initialized. In addition, the sign functions with respect to the bit nodes are also initialized, signb(e). These calculations are performed as follows: Medge b ( ⅇ ) = ln 1 - exp ( met ( i ) ) 1 + exp ( met ( i ) ) , sign b ( ⅇ ) = sign ( met ( i ) ) . ( EQ 23 ) Step 3. For every check node j that is communicatively coupled to its corresponding bit nodes, Ec(j) is the set of all edges connected to that check node j. The decoding processing operates by updating the edge messages with respect to the bit nodes, Medgec(e), for every e∈Ec(j). These calculations are performed as provided below: Medge c ( e ) = ∑ f ∈ E c ( j ) ∖ { e } Medge b ( f ) , sign c ( e ) = ∏ f ∈ E c ( j ) ∖ { e } sign b ( f ) ( EQ 24 ) Step 4. For every bit node i that is communicatively coupled to its corresponding check nodes, Eb(i) is the set of all edges connected to that bit node i. the following threshold function is then computed: P ( i ) = sign ( met ( i ) ) ln 1 - exp ( met ( i ) ) 1 + exp ( met ( i ) ) + = ∑ e ∈ E b ( i ) sign c ( ⅇ ) ln 1 - exp ( Medge c ( ⅇ ) ) 1 + exp ( Medge c ( ⅇ ) ) ( EQ 25 ) For every e∈Eh(i), compute the following function: q ( ⅇ ) = P ( i ) - sign c ( ⅇ ) ln 1 - exp ( Medge c ( ⅇ ) ) 1 + exp ( Medge c ( ⅇ ) ) ( EQ 26 ) The edge messages with respect to the bit nodes, Medgeb(e), are updated using the intermediate function, q(e), calculated below. Medge b ( ⅇ ) = ln 1 - exp ( q ( ⅇ ) ) 1 + exp ( q ( ⅇ ) ) , sign b ( ⅇ ) = - sign ( q ( ⅇ ) ) . If the current decoding iteration is the last decoding iteration, then this decoding functionality operates by outputting soft information corresponding to the most recently updated edge messages with respect to the bit nodes, Medgeb(e), and making subsequent hard decisions thereon to make a best estimate of the at least one information bit contained within the originally received vector, y=(y0, . . .yn−1). It is noted that the received vector, y=(y0, . . . yn−1), is extracted from a received continuous time signal received by a communication device (after having undergone any appropriate preprocessing such as filtering, sampling, demodulation and symbol mapping, and so on). If the current decoding iteration is not in fact the last decoding iteration, then this decoding functionality operates to go back to the Step 3 indicated above. The Step 3 and the Step 4 can continue to operate alternatively to perform iterative decoding processing of updating edge messages with respect to the check nodes, Medgec(e), and updating edge messages with respect to the bit nodes, Medgeb(e), respectively. After having performed a last decoding iteration, and when hard decisions are to be made, the hard decisions (e.g., best estimates) that are output for the bit of concern are made using the above-calculated threshold functions as follows: Output best estimate for bit as bi=1 if P(i)≧0. Output best estimate for bit as bi=0 otherwise. This earlier calculated function, P(i), may be viewed as being a threshold by which the final hard decisions are to be made with respect to the bits as being of a value of 0 and a value of 1, respectively. FIG. 28 is a diagram illustrating an embodiment of check node and bit node estimation functionality (employing LR (Likelihood Ratio) decoding at check node side) according to the invention. As also described above with respect to the FIG. 25, the manner in which check node estimation and bit node estimation are performed in accordance with the likelihood decoding, the functionality employed when estimating the bit node and estimating the check node within the LDPC decoding processing employed according LR decoding as shown with respect to this diagram. The check node estimate is initially described below. This description is provided when considering the check node i. Ec(j)={(ik,j)|k=0, . . . ,n−1} is the set of all edges connecting this check node i to its corresponding bit nodes. The codeword that is being decoded is provided as b=(b0, . . . ,bN−1). By the definition of the parity check according to the LDPC code being employed, the following relationship is true: ∑ k = 0 n - 1 b i k = 0 ( EQ 27 ) For every edge e∈Ec(j), (which may be represented as e=(i0,j) for convenience), then the following probability function is calculated d e = Pr ( ∑ k = 0 n - 1 b i k = 0 ❘ b i 0 = 0 ) = Pr ( ∑ k = 1 n - 1 b i k = 0 ) ( EQ 28 ) and ak=Pr(bik=0). Then their respective ratios are provided as follows: z e = 1 - d e d e and x k = 1 - a k a k . When n=3, without lost of generality, let a=a1, b=a2, x=x1 and y=x2, and, then z = ( 1 - a ) b + ( 1 - b ) a a b + ( 1 - a ) ( 1 - b ) = ( 1 - a ) / a + ( 1 - b ) / b 1 + ( 1 - a ) ( l - b ) / ( a b ) = x + y 1 + x y ( EQ 29 ) The following map, F(x), is defined as follows: F ( x ) = 1 - x 1 + x , x ≠ 1. Based on this definition of the map, F(x), then the map of the variable z if provided as follows (where z is defined in terms of x and y above). F ( z ) = 1 + x y - x - y 1 + x y + x + y = ( 1 - x x + 1 ) ( 1 - y 1 + y ) = F ( x ) F ( y ) ( EQ 30 ) In general, let e = ( i 1 , j ) , d n - 1 = Pr ( ∑ k = 0 , k ≠ l n - 1 b i k = 0 ) , and zn−=(1−dn−1)/dn−1, then the following relationship is also true: z e = z n - 1 + x n - 1 z n - 1 x n - 1 + 1 and F ( z e ) = F ( z n - 1 ) F ( x n - 1 ) = ∏ k ≠ l F ( x k ) ( EQ 31 ) As can be seen, the estimate of the check node, zc, is reduced to being a product of terms function within the (EQ 31). This is achieved borrowing on the simplicity in calculation complexity provided by the map, F(x). In the BP (Belief Propagation) decoding approach, the LR (Likelihood Ratio) x of bit i can be computed by the LR of its corresponding check nodes zc, e∈Eb(i). This LR of the bit i may be calculated using a product of terms function as provided below: x = ∏ e ∈ E b ( i ) z e . Since the edge messages passed from the check nodes are uc=F(zc), and since the following relationship is true, F ( F ( u ) ) = 1 - 1 - u 1 + u 1 + 1 - u 1 + u = u ( EQ 32 ) then, the following simplified calculation may be employed to calculate the LR of bit i (which is represented as x). x = F ( ∏ e ∈ E b ( i ) u e ) = ∏ e ∈ E b ( i ) F ( u e ) . ( EQ 33 ) Again, the LR of the bit i may be calculated using a product of terms function that is also a function of the map, F(x). FIG. 29 is a diagram illustrating an embodiment of LDPC decoding functionality (employing LLR (Log Likelihood Ratio) processing) according to the invention. Again, somewhat analogously to the other decoding embodiments described above, the decoding processing of this particular embodiment may also be viewed as being performed in 4 separate steps. As also within one of the particular embodiments describe above, the log domain version by which this decoding functionality may be implemented is presented below. Of course, a non-log domain version could also be implemented without departing from the scope and spirit of the invention. To perform the computations involved with this embodiment within the log domain, it is once again necessary to accommodate the logarithm of a negative value as is also discussed above within another embodiment. In the following description, only the LLR (Log-Likelihood Ratio) decoding approach is presented. A LR (Likelihood Ratio) decoding approach may similarly be employed as is described with respect to the diagram and accompanying description of the FIG. 27. Before the decoding procedure corresponding to this embodiment is presented within greater detail, a new function, L, is defined. This new function, L, is a function of the edge messages with respect to the bit nodes, Medgeb(e). This new function, L, is presented below: L ( x ) = ln 1 - exp ( x ) 1 + exp ( x ) ( EQ 34 ) In a hardware implementation (e.g., within an actual communication device that performs decoding according to this approach), this function, L, can be realized by a LUT (look-up table). This LUT may be implemented using any of a variety of means including ROM (Read Only Memory) and/or various other types of memory. Moreover, the following intermediate variables, A and B, are defined as follows: A=sign(F(x)), and B=ln|F(x)|. Using these intermediate variables, A and B, the map, F(x), may be calculated as follows: F(x)=A exp (B). Since 0≦x≦1, then the map, F(x), has the following range |F(x)|≦1. Therefore, the intermediate variable, B, has the following range B<0. Then, the following relationship is also true. l n ( F ( F ( x ) ) ) = ln 1 - A exp ( B ) 1 + A exp ( B ) = A × L ( B ) = sign ( F ( x ) ) × L ( ln F ( x ) ) ( EQ 35 ) The LLR (Log-Likelihood Ratio) decoding procedure is provided below with respect to this diagram. Again, as within other embodiments, the decoding processing may be viewed as being performed in 4 separate steps. As also within other embodiments described above, the decoding processing of this embodiment operates on a received vector y (e.g., where y=(y0, . . . yN−1) is the received vector). Step 1. The LLR metric is computed for every position i=0, . . . ,n−1 using the received vector, y, and according to the Gaussian distribution. For example, this metric may be calculated as follows: metric ( i ) = log p ( y i ❘ b i = 1 ) p ( y i ❘ b i = 0 ) = 2 σ 2 y i ( EQ 36 ) Step 2. For every edge e, the edge messages with respect to the bit nodes, Medgeb(e), are initialized using the above-calculated metric as follows: Medgeb(e)=metric(b(e)). Step 3. For every check node j, Ec(j) is the set of all of the edges connected from the check node j to its corresponding bit nodes. The following intermediate variables, A and B, are calculated as follows: A = ∏ e ∈ E c ( j ) sign ( Medge b ( e ) ) , and B = ∑ e ∈ E c ( j ) L ( Medge b ( e ) ) . The edge messages with respect to the check nodes, Medgec(e), are updated for every e∈Ec(j) as follows: Medgec(e)=A×sign(Medgeb(e))×L(B−L(Medgeb(e))) (EQ 37) Step 4. For every bit node i, let Eb(i) be the set of all edges connected from this bit node i to its corresponding check nodes. The estimate of the LLR, ri, and the APP (a posteriori probability) of the bit node i may be calculated as follows: r i = metric ( i ) + ∑ e ∈ E b ( i ) Medge c ( e ) ( EQ 38 ) The estimate of the LLR, ri, may be viewed as being a threshold function for subsequent hard decision making of individual bits of a codeword. The edge messages with respect to the bit nodes, Medgeb(e), are updated for every e∈Eb(i) using the estimate of the LLR, ri, as follows: Medgeb(e)=ri−Medgec(e) (EQ 39) If the current decoding iteration is the last decoding iteration, then this decoding functionality operates by outputting soft information corresponding to the most recently updated edge messages with respect to the bit nodes, Medgeb(e), and making subsequent hard decisions thereon to make a best estimate of the at least one information bit contained within the originally received vector, y=(y0, . . . yn−1). Again, as within other of the embodiments described herein, it is noted that the received vector, y=(y0, . . . yn−1), is extracted from a received continuous time signal received by a communication device (after having undergone any appropriate preprocessing such as filtering, sampling, demodulation and symbol mapping, and so on). If the current decoding iteration is not in fact the last decoding iteration, then this decoding functionality operates to go back to the Step 3 indicated above. The Step 3 and the Step 4 can continue to operate alternatively to perform iterative decoding processing of updating edge messages with respect to the check nodes, Medgec(e), and updating edge messages with respect to the bit nodes, Medgeb(e), respectively. After having performed a last decoding iteration, and when hard decisions are to be made, the hard decisions (e.g., best estimates) that are output for the bit of concern are made using the above-calculated threshold functions as follows: Output best estimate for bit as bi=1 if ri≧0. Output best estimate for bit as bi=0 otherwise. This earlier calculated estimate of the LLR, ri, may be viewed as being a threshold by which the final hard decisions are to be made with respect to the bits as being of a value of 0 and a value of 1, respectively. FIG. 30 is a diagram illustrating an embodiment of check node processing functionality employing function, L, (shown using LDPC decoding employing LLR processing) according to the invention. This diagram may be viewed with respect to the check node processing functional block shown and described within the preceding diagram. The function, L, operates to transform the incoming edge messages with respect to the bit nodes, Medgeb(e), such that the calculations that are necessary to perform updating of the edge messages with respect to the check nodes, Medgec(e), may be performed using only a product of terms function. Alternatively, this function, L, operates to transform the incoming edge messages with respect to the bit nodes, Medgeb(e), such that the calculations that are necessary to perform updating of the edge messages with respect to the check nodes, Medgec(e), may be performed using only a sum of terms function when implemented within the log domain. After the edge messages with respect to the bit nodes, Medgeb(e), have been transformed using the function, L, the edge messages with respect to the check nodes, Medgec(e), are updated within the check node processing functional block using the appropriately transformed edge messages with respect to the bit nodes, Medgeb(e). This updating of the edge messages with respect to the check nodes, Medgec(e), may now be performed using only a product of terms function. Alternatively, this updating of the edge messages with respect to the check nodes, Medgec(e), may now be performed using only a sum of terms function when implemented in the log domain. After the edge messages with respect to the check nodes, Medgec(e), have been updated, then the now-updated edge messages with respect to the check nodes, Medgec(e), are passed again through the function, L; it is noted that the function L and the inverse of L are the same function e.g., L=L−1 (as can also be seen from the description above). Therefore, the functional block portion that is used to implemented the function L may also be used again (when performing the operation of L−1) to transform to and from the domain that allows the use of a product of terms function only (or a sum of terms function only, when implemented within the log domain). It is also noted that the functionality of the function, L, may be implemented within the check node processing functional block or outside of the check node processing functional block. That is to say, when implementing a device to perform the functionality described within this embodiment, the function, L, may be implemented within a processor and/or circuitry that performs the check node processing. Alternatively, the function, L, may be implemented using a different circuitry portion that is external to the check node processing functional block. In whichever implementation, the function, L, enables the use of a product of terms function (or sum of terms function within the log domain) when updating the edge messages with respect to the check nodes, Medgec(e), within the check node processing functional block. FIG. 31A is a diagram illustrating an embodiment of separate check node processing and bit node processing functional blocks. In typical embodiments, two separate circuitry portions are required to perform updating of the edge messages with respect to the check nodes, Medgec(e), and updating of the edge messages with respect to the bit nodes, Medgeb(e), respectively. More specifically, in most prior art approaches, the use of a single circuitry portion, or bit node processor, operates to perform the updating to the edge messages with respect to the bit nodes, Medgeb(e). Similarly, the use of a single circuitry portion, or check node processor, operates to perform the updating to the edge messages with respect to the check nodes, Medgec(e). Each of these single circuitry portions, or the bit node processor and the check node processor, is typically communicatively coupled to a memory portion to assist in the memory management of the edge messages that are passed back and forth between each of these two separate circuitry portions, or the bit node processor and the check node processor. FIG. 31B is a diagram illustrating an embodiment of a single functional block that is operable to perform calculations of both check node processing and bit node processing according to the invention. The use of the novel function, L, allows for the use of a single circuitry portion, or processor, to perform the calculations necessary for both bit node processing and check node processing. This single circuitry portion, or processor, may be communicatively coupled to a memory portion to assist in the memory management of the edge messages that are passed back and forth between this single circuitry portion when performing the updating to the edge messages with respect to the check nodes, Medgec(e), and the updating of the edge messages with respect to the bit nodes, Medgeb(e). By using this new function, L, the same circuitry portion, or processor, can be used to perform edge message initialization, check node processing, and also bit processing. This is a significant departure from any decoding approach within the prior art for decoding LDPC coded signals. The use of a single circuitry portion can significantly reduce the total hardware that is required to implement a communication device operable to decode LDPC coded signals. FIG. 32 is a diagram illustrating an embodiment of a single functional block (e.g., processor) that is operable to perform calculations for edge message initialization, check node processing, and bit node processing according to the invention. This diagram shows the exchange of data to and from memory and a single circuitry portion, or processor, that is operable to perform calculations for edge message initialization, check node processing, and bit node processing according. During a first time period, edge message initialization is performed. Zero (e.g., 0) valued edge messages with respect to the check nodes, Medgec(e), are received by the processor from the memory, and a 1st decoding iteration of updating edge messages with respect to the bit nodes, Medgeb(e), is performed. These updated edge messages with respect to the bit nodes, Medgeb(e) are passed back to the memory for subsequent retrieval and use by the processor when performing updating of the edge messages with respect to the check nodes, Medgec(e). During a second time period, the recently updated edge messages with respect to the bit nodes, Medgeb(e), are received by the processor from memory. These edge messages with respect to the bit nodes, Medgeb(e), undergo the appropriate transformation by the function, L, so that the updating of the edge messages with respect to the check nodes, Medgec(e), may be performed using only a product of terms function (or sum of terms function within the log domain). After the edge messages with respect to the check nodes, Medgec(e), have been updated within the processor, they are again passed through the function, L, before being stored back in memory for subsequent retrieval and use by the processor when performing updating of the edge messages with respect to the bit nodes, Medgeb(e). The processing during this time period may be viewed as being a 1st decoding iteration of updating edge messages with respect to the check nodes, Medgec(e). During a third time period, the recently updated edge messages with respect to the check nodes, Medgec(e), are received by the processor from memory. The edge messages with respect to the bit nodes, Medgeb(e), are then updated using the bit node processing functionality within the processor. After the edge messages with respect to the bit nodes, Medgeb(e), have been updated within the processor, they are again passed back to memory for subsequent retrieval and use by the processor when performing updating of the edge messages with respect to the check nodes, Medgec(e), during the next decoding iteration. The processing during this time period may be viewed as being a 2nd decoding iteration of updating edge messages with respect to the bit nodes, Medgeb(e). It is noted that the processing that is performed during the edge message initialization and the bit node processing is identical with the exception that 0 valued edge messages with respect to the check nodes, Medgec(e), are employed during edge message initialization. During subsequent decoding iterations of bit node processing, the most recently updated edge messages with respect to the check nodes, Medgec(e), are employed during bit node processing. FIG. 33 is a flowchart illustrating an embodiment of a method for decoding LDPC coded signals using only multiplication (or log domain addition) on both sides of LDPC bipartite graph according to the invention. The method involves receiving a continuous time signal. The information bits that have been encoded within this continuous time signal have been encoded using LDPC encoding. This LDPC encoding may be viewed as being parallel-block LDPC encoding. Upon the receiving of this continuous time signal, it is also noted that the method may involve performing any necessary down-conversion of a first continuous time signal (e.g., the originally received continuous time signal) thereby generating a second continuous time signal. This down conversion may be performed by direct conversion from carrier frequency to baseband, or it may alternatively be performed by passing through an IF (Intermediate Frequency) as well without departing from the scope and spirit of the invention. The method then involves sampling the first (or second) continuous time signal (e.g., using an ADC) thereby generating a discrete time signal and extracting I, Q (In-phase, Quadrature) components there from. The method then also involves demodulating the I, Q components and performing symbol mapping of the I, Q components thereby generating a sequence of discrete-valued modulation symbols. The method then involves performing edge message updating using only multiplication (or log domain addition) on both sides of LDPC bipartite graph. This is performed for predetermined number of decoding iterations within this particular embodiment. This updating may be performed a number of ways. For example, the method may involve employing likelihood for both edges messages with respect to check nodes and edges messages with respect to bit nodes. Alternatively, the method may involve employing likelihood ratio for edges messages with respect to bit nodes. The method also involves making hard decisions based on soft information corresponding to the finally updated edge messages. Using these hard decisions, the method then involves outputting a best estimate of the transmitted codeword (having at least one information bit included therein) that is extracted from the received continuous time signal. FIG. 34 is a flowchart illustrating an alternative embodiment of a method for decoding LDPC coded signals using only multiplication (or log domain addition) on both sides of LDPC bipartite graph according to the invention. Initially, this particular method operates very similarly to the embodiment described above with respect to the FIG. 34. The method involves receiving a continuous time signal. The information bits that have been encoded within this continuous time signal have been encoded using LDPC encoding. This LDPC encoding may be viewed as being parallel-block LDPC encoding. Upon the receiving of this continuous time signal, it is also noted that the method may involve performing any necessary down-conversion of a first continuous time signal (e.g., the originally received continuous time signal) thereby generating a second continuous time signal. This down conversion may be performed by direct conversion from carrier frequency to baseband, or it may alternatively be performed by passing through an IF (Intermediate Frequency) as well without departing from the scope and spirit of the invention. The method then involves sampling the first (or second) continuous time signal (e.g., using an ADC) thereby generating a discrete time signal and extracting I, Q (In-phase, Quadrature) components there from. The method then also involves demodulating the I, Q components and performing symbol mapping of the I, Q components thereby generating a sequence of discrete-valued modulation symbols. The method then involves performing edge message updating using only multiplication (or log domain addition) on both sides of LDPC bipartite graph. This updating may be performed a number of ways. For example, the method may involve employing likelihood for both edges messages with respect to check nodes and edges messages with respect to bit nodes. Alternatively, the method may involve employing likelihood ratio for edges messages with respect to bit nodes. However, this method now departs from the operation of the method of the FIG. 33. In this particular embodiment, the method involves making hard decisions based on soft information corresponding to edge messages to produce a current estimate of the codeword. It is noted that this is performed after bit engine processing has finished at least one decoding iteration. After this current estimate of the codeword is made, then the method involves performing syndrome checking of the current estimate of the codeword. This is performed to determine if this current estimate of the codeword indeed passes the syndrome check. If the syndrome check does NOT pass, then the method involves returning to the edge message updating using only multiplication (or log domain addition) on both sides of LDPC bipartite graph. However, if it is found that the syndrome check does in fact pass, then the method involves outputting a best estimate of the transmitted codeword (having at least one information bit included therein) that is extracted from the received continuous time signal. It is also noted that the methods described within the preceding figures may also be performed within any of the appropriate system and/or apparatus designs (communication systems, communication transmitters, communication receivers, communication transceivers, and/or functionality described therein) that are described above without departing from the scope and spirit of the invention. Moreover, it is also noted that the various functionality, system and/or apparatus designs, and method related embodiments that are described herein may all be implemented in the logarithmic domain (e.g., log domain) thereby enabling multiplication operations to be performed using addition and thereby enabling division operations to be performed using subtraction. In view of the above detailed description of the invention and associated drawings, other modifications and variations will now become apparent. It should also be apparent that such other modifications and variations may be effected without departing from the spirit and scope of the invention.
|
G
|
G06
|
G06K
|
5
|
04
|
|||
11946256
|
US20080307774A1-20081218
|
SELECTIVE CATALYST REDUCTION LIGHT-OFF STRATEGY
|
ACCEPTED
|
20081202
|
20081218
|
[]
|
F01N320
|
["F01N320", "F01N336"]
|
8037673
|
20071128
|
20111018
|
060
|
284000
|
67584.0
|
NGUYEN
|
TU
|
[{"inventor_name_last": "Gonze", "inventor_name_first": "Eugene V.", "inventor_city": "Pinckney", "inventor_state": "MI", "inventor_country": "US"}, {"inventor_name_last": "Paratore, JR.", "inventor_name_first": "Michael J.", "inventor_city": "Howell", "inventor_state": "MI", "inventor_country": "US"}]
|
An emissions control system comprises a temperature determination module and an emissions control module. The temperature determination module determines a first temperature of a heater element of a diesel particulate filter (DPF) assembly in an exhaust system and determines a second temperature of a catalyst of the DPF assembly. The emissions control module selectively activates the heater element, selectively initiates a predefined combustion process in an engine based upon the first temperature, and selectively starts a reductant injection process based upon the second temperature.
|
1. An emissions control system comprising: a temperature determination module that determines a first temperature of a heater element of a diesel particulate filter (DPF) assembly in an exhaust system and that determines a second temperature of a catalyst of said DPF assembly; and an emissions control module that selectively activates said heater element, that selectively initiates a predefined combustion process in an engine based upon said first temperature, and that selectively starts a reductant injection process based upon said second temperature. 2. The emissions control system of claim 1 wherein said heater element includes a plurality of zones. 3. The emissions control system of claim 2 further comprising a heater control module that repeatedly activates selected ones of said zones of said heater element in a predefined order. 4. The emissions control system of claim 1 wherein said emissions control module activates said heater element after starting said engine. 5. The emissions control system of claim 1 wherein said emissions control module initiates said predefined combustion process when said first temperature is greater than a first temperature threshold. 6. The emissions control system of claim 1 wherein said engine provides unburned fuel to said exhaust system during said predefined combustion process. 7. The emissions control system of claim 6 wherein said temperature determination module estimates said second temperature based upon heating resulting from combustion of said unburned fuel. 8. The emissions control system of claim 1 wherein said temperature determination module determines a third temperature of a substrate of said DPF assembly and estimates said second temperature based upon said third temperature. 9. The emissions control system of claim 1 wherein said temperature determination module estimates said first temperature based upon power delivered to said heater element. 10. The emissions control system of claim 1 wherein said emissions control module starts said reduction injection process when said second temperature is greater than a second temperature threshold. 11. The emissions control system of claim 1 wherein said emissions control module deactivates said heater element after said predefined combustion process is initiated. 12. The emissions control system of claim 1 further comprising an injector that injects reductant into said exhaust system once said reduction injection process is started. 13. A method comprising: determining a first temperature of a heater element of a diesel particulate filter (DPF) assembly in an exhaust system; determining a second temperature of a catalyst of said DPF assembly; selectively activating said heater element; selectively initiating a predefined combustion process in an engine based upon said first temperature; and selectively starting a reductant injection process based upon said second temperature. 14. The method of claim 13 further comprising repeatedly activating selected zones of said heater element in a predefined order. 15. The method of claim 13 further comprising activating said heater element after starting said engine. 16. The method of claim 13 further comprising initiating said predefined combustion process when said first temperature is greater than a first temperature threshold. 17. The method of claim 13 further comprising providing unburned fuel to said exhaust system during said predefined combustion process. 18. The method of claim 17 further comprising estimating said second temperature based upon heating resulting from combustion of said unburned fuel. 19. The method of claim 13 further comprising: determining a third temperature of a substrate of said DPF assembly; and estimating said second temperature based upon said third temperature. 20. The method of claim 13 further comprising estimating said first temperature based upon power delivered to said heater element. 21. The method of claim 13 further comprising starting said reduction injection process when said second temperature is greater than a second temperature threshold. 22. The method of claim 13 further comprising deactivating said heater element after said predefined combustion process is initiated. 23. The method of claim 13 further comprising injecting reductant into said exhaust system once said reduction injection process is started.
|
<SOH> BACKGROUND <EOH>The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. Diesel engines typically produce torque more efficiently than gasoline engines. This increase in efficiency may be due to an increased compression ratio and/or the combustion of diesel fuel, which has a higher energy density than that of gasoline. The combustion of diesel fuel produces particulate. The particulate is filtered from exhaust by a diesel particulate filter (DPF). With time, the DPF may fill with particulate, thereby restricting the flow of the exhaust. The particulate may be combusted by a process referred to as regeneration. Regeneration may be accomplished, for example, by injecting fuel into the exhaust stream after the combustion of the diesel fuel. One or more catalysts may be disposed in the exhaust stream and may combust the injected fuel. The combustion of the fuel by the catalysts generates heat, thereby increasing the temperature of the exhaust. The increased temperature of the exhaust may burn the remainder of the particulate trapped in the DPF.
|
<SOH> SUMMARY <EOH>An emissions control system comprises a temperature determination module and an emissions control module. The temperature determination module determines a first temperature of a heater element of a diesel particulate filter (DPF) assembly in an exhaust system and determines a second temperature of a catalyst of the DPF assembly. The emissions control module selectively activates the heater element, selectively initiates a predefined combustion process in an engine based upon the first temperature, and selectively starts a reductant injection process based upon the second temperature. In further features, the heater element includes a plurality of zones. The emissions control system further comprises a heater control module. The heater module repeatedly activates selected ones of the zones of the heater element in a predefined order. The emissions control module activates the heater element after starting the engine. The emissions control module initiates the predefined combustion process when the first temperature is greater than a first temperature threshold. In other features, the engine provides unburned fuel to the exhaust system during the predefined combustion process. The temperature determination module estimates the second temperature based upon heating resulting from combustion of the unburned fuel. The temperature determination module determines a third temperature of a substrate of the DPF assembly and estimates the second temperature based upon the third temperature. In still further features, the temperature determination module estimates the first temperature based upon power delivered to the heater element. The emissions control module starts the reduction injection process when the second temperature is greater than a second temperature threshold. The emissions control module deactivates the heater element after the predefined combustion process is initiated. The emissions control system further comprises an injector that injects reductant into the exhaust system once the reduction injection process is started. A method comprises determining a first temperature of a heater element of a diesel particulate filter (DPF) assembly in an exhaust system, determining a second temperature of a catalyst of the DPF assembly, selectively activating the heater element, selectively initiating a predefined combustion process in an engine based upon the first temperature, and selectively starting a reductant injection process based upon the second temperature. In other features, the method further comprises repeatedly activating selected zones of the heater element in a predefined order. The method further comprises activating the heater element after starting the engine. The method further comprises initiating the predefined combustion process when the first temperature is greater than a first temperature threshold. In further features, the method further comprises providing unburned fuel to the exhaust system during the predefined combustion process. The method further comprises estimating the second temperature based upon heating resulting from combustion of the unburned fuel. The method further comprises determining a third temperature of a substrate of the DPF assembly and estimating the second temperature based upon the third temperature. In still further features, the method further comprises estimating the first temperature based upon power delivered to the heater element. The method further comprises starting the reduction injection process when the second temperature is greater than a second temperature threshold. The method further comprises deactivating the heater element after the predefined combustion process is initiated. The method further comprises injecting reductant into the exhaust system once the reduction injection process is started. Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
|
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 60/936,098, filed on Jun. 18, 2007. The disclosure of the above application is incorporated herein by reference in its entirety. FIELD The present disclosure relates to vehicle emissions and more particularly to selective catalyst reduction. BACKGROUND The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. Diesel engines typically produce torque more efficiently than gasoline engines. This increase in efficiency may be due to an increased compression ratio and/or the combustion of diesel fuel, which has a higher energy density than that of gasoline. The combustion of diesel fuel produces particulate. The particulate is filtered from exhaust by a diesel particulate filter (DPF). With time, the DPF may fill with particulate, thereby restricting the flow of the exhaust. The particulate may be combusted by a process referred to as regeneration. Regeneration may be accomplished, for example, by injecting fuel into the exhaust stream after the combustion of the diesel fuel. One or more catalysts may be disposed in the exhaust stream and may combust the injected fuel. The combustion of the fuel by the catalysts generates heat, thereby increasing the temperature of the exhaust. The increased temperature of the exhaust may burn the remainder of the particulate trapped in the DPF. SUMMARY An emissions control system comprises a temperature determination module and an emissions control module. The temperature determination module determines a first temperature of a heater element of a diesel particulate filter (DPF) assembly in an exhaust system and determines a second temperature of a catalyst of the DPF assembly. The emissions control module selectively activates the heater element, selectively initiates a predefined combustion process in an engine based upon the first temperature, and selectively starts a reductant injection process based upon the second temperature. In further features, the heater element includes a plurality of zones. The emissions control system further comprises a heater control module. The heater module repeatedly activates selected ones of the zones of the heater element in a predefined order. The emissions control module activates the heater element after starting the engine. The emissions control module initiates the predefined combustion process when the first temperature is greater than a first temperature threshold. In other features, the engine provides unburned fuel to the exhaust system during the predefined combustion process. The temperature determination module estimates the second temperature based upon heating resulting from combustion of the unburned fuel. The temperature determination module determines a third temperature of a substrate of the DPF assembly and estimates the second temperature based upon the third temperature. In still further features, the temperature determination module estimates the first temperature based upon power delivered to the heater element. The emissions control module starts the reduction injection process when the second temperature is greater than a second temperature threshold. The emissions control module deactivates the heater element after the predefined combustion process is initiated. The emissions control system further comprises an injector that injects reductant into the exhaust system once the reduction injection process is started. A method comprises determining a first temperature of a heater element of a diesel particulate filter (DPF) assembly in an exhaust system, determining a second temperature of a catalyst of the DPF assembly, selectively activating the heater element, selectively initiating a predefined combustion process in an engine based upon the first temperature, and selectively starting a reductant injection process based upon the second temperature. In other features, the method further comprises repeatedly activating selected zones of the heater element in a predefined order. The method further comprises activating the heater element after starting the engine. The method further comprises initiating the predefined combustion process when the first temperature is greater than a first temperature threshold. In further features, the method further comprises providing unburned fuel to the exhaust system during the predefined combustion process. The method further comprises estimating the second temperature based upon heating resulting from combustion of the unburned fuel. The method further comprises determining a third temperature of a substrate of the DPF assembly and estimating the second temperature based upon the third temperature. In still further features, the method further comprises estimating the first temperature based upon power delivered to the heater element. The method further comprises starting the reduction injection process when the second temperature is greater than a second temperature threshold. The method further comprises deactivating the heater element after the predefined combustion process is initiated. The method further comprises injecting reductant into the exhaust system once the reduction injection process is started. Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: FIG. 1 is a functional block diagram of an exemplary vehicle according to the principles of the present disclosure; FIG. 2 is an exemplary cross sectional diagram of a diesel particulate filter assembly according to the principles of the present disclosure; FIG. 3 is an functional block diagram of an exemplary vehicle according to the principles of the present disclosure; FIG. 4 is a functional block diagram of an exemplary emissions control system according to the principles of the present disclosure; and FIG. 5 is a flowchart depicting exemplary steps performed by an emissions control system according to the principles of the present disclosure. DETAILED DESCRIPTION The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure. As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. Referring now to FIG. 1, a functional block diagram of an exemplary vehicle 100 is presented. The vehicle 100 includes a diesel engine system 102. The diesel engine system 102 is described for example only and the principles of the present disclosure may be implemented in other types of engine systems. For example, the principles of the present disclosure may be applied to a gasoline engine system and/or a homogenous charge compression ignition engine system. The diesel engine system 102 includes an engine 104 that combusts a mixture of air and diesel fuel to produce torque. Resulting exhaust is expelled from the engine 104 into an exhaust system 106. The exhaust system 106 includes an exhaust manifold 108, a diesel oxidation catalyst (DOC) 110, a reductant injector 112, a mixer 114, and a diesel particulate filter (DPF) assembly 116. The exhaust system 106 may also include an exhaust gas recirculation (EGR) valve (not shown) that may recirculate a portion of the exhaust into the engine 104. The exhaust flows from the engine 104 through the exhaust manifold 108 to the DOC 110. The DOC 110 oxidizes particulate in the exhaust as the exhaust flows through the DOC 110. For example only, the DOC 110 may oxidize particulate such as hydrocarbons and/or carbon oxides. The reductant injector 112 may inject a reductant, such as ammonia or urea, into the exhaust system. The mixer 114, which may be implemented as a baffle, agitates the exhaust and/or the injected reductant. In this manner, the mixer 114 may create a reductant-exhaust aerosol by mixing the reductant with the exhaust. The DPF assembly 116 filters particulate from the exhaust, which may accumulate within the DPF assembly 116. Particulate matter accumulating within the DPF assembly 116 may restrict the exhaust flow through the DPF assembly 116. The particulate may be removed from the DPF assembly 116 by a process referred to as regeneration. Referring now to FIG. 2, an exemplary cross-sectional diagram of the DPF assembly 116 is presented. The DPF assembly 116 includes a substrate 220, a heater element 222, and a diesel particulate filter (DPF) element 224. The exhaust enters the DPF assembly 116 through an inlet 225 and flows through the substrate 220, the heater element 222, and then the DPF element 224. The exhaust exits the DPF assembly 116 though an outlet 226. The substrate 220 may, for example, hold the heater element 222 in contact with the DPF element 224, make the exhaust flow more laminar (i.e., straighten the direction of the exhaust flow) through the DPF element 224, and/or prevent radiant heat from being lost from the DPF assembly 116. The heater element 222 may be arranged in, for example only, a grid. The exhaust may enter the DPF element 224 through a front section 228 of the DPF element 224, which may be in contact with or close to the heater element 222. The DPF element 224 may include, for example, alternating open and closed channels (not shown) that force the exhaust through walls (not shown) of the DPF element 224. The walls of the DPF element 224 filter particulate from the exhaust. The walls of the DPF element 224 may be porous, may be arranged in a honeycomb fashion, and may be made of, for example only, a ceramic or cordierite material. The exhaust exits the DPF element 224 through a rear section 230 of the DPF element 224. The regeneration process may begin once the heater temperature reaches a threshold, such as 800° C. The heat generated by the combustion of particulate near the front section 228 is carried by the exhaust through the DPF element 224, thereby combusting particulate throughout the DPF element 224. A selective catalyst reductant (SCR) catalyst is applied to all of or a portion of the DPF element 224. The SCR catalyst may be applied to, for example, the front section 228, the walls, and/or the rear section 230 of the DPF element 224. The SCR catalyst may be applied to the DPF element 224 in any pattern, such as striped, and the SCR catalyst may be applied in varying degrees. For example only, the SCR catalyst may be applied more heavily toward the rear section 230 of the DPF element 224 than the front section 228. The SCR catalyst absorbs reductant injected by the reductant injector 112 and reacts with nitrogen oxides (NOX) and/or other pollutants in the exhaust. In this manner, the SCR catalyst may reduce the NOX emissions of the vehicle 100. The SCR catalyst may be effective in reducing (reacting with) NOX once the temperature of the SCR catalyst exceeds a threshold. For example only, the threshold, referred to as TSCR, may be 200° C. If the reductant is injected when the SCR temperature is below TSCR, the reductant may compromise the function of the SCR catalyst. Upon starting the engine 104, the SCR temperature is likely below the TSCR threshold. Accordingly, the SCR catalyst may not effectively react with NOX present in the exhaust upon starting the engine 104. Engine exhaust will eventually bring the SCR temperature to TSCR. To shorten the time before the SCR temperature reaches TSCR, heat can be generated by combusting fuel at the heater element 222. To allow this, the heater element 222 may be coated with a catalyst that ignites fuel present in the exhaust when the heater element 222 reaches a threshold temperature. Accordingly, when the temperature of the heater element 222 reaches the threshold temperature, the engine 104 may be instructed to increase the amount of fuel present in the exhaust. This fuel combusts at the heater element 222 and heats the SCR catalyst. Referring now to FIG. 3, a functional block diagram of an exemplary vehicle 300 is presented. The vehicle 300 includes the diesel engine system 102 and the exhaust system 106, which includes the DPF assembly 116. Power is supplied to a heater control module 302 and a powertrain control module (PCM) 304 by, for example, a battery 306 and/or a generator 308. Power to the PCM 304 may be switched by a switch 309, which may be controlled by an ignition key. For example only, the battery 306 may supply twelve (12) Volts, and the generator 308 may supply 14.5±0.5 Volts on average. The PCM 304 may control, for example, combustion of the diesel fuel within the engine 104, actuation of the heater control module 302, and injection of the reductant by the reductant injector 112. The heater control module 302 selectively applies power to the heater element 222 based upon a heater control signal from the PCM 304. In various implementations, the heater element 222 may have a resistance of 0.1Ω, a power rating of 2300 Watts, a voltage rating of 12 Volts, and a current rating of 192 Amps. A resistor 332 having a known resistance value may be connected in series with the power supplied to the heater control module 302. The PCM 304 may measure a voltage at either end of the resistor 332 to determine power supply voltage for the heater control module 302. The PCM 304 may also measure the voltage drop across the resistor 332. The current supplied to the heater control module 302 can then be determined by dividing this voltage drop by the known resistance value. The heater element 222 of the DPF assembly 116 may be divided into one or more zones. For example only, the heater element 222 may be divided into 5 zones, and the zones may be arranged in any manner, such as a zone arrangement graphically depicted at 310. The PCM 304 may instruct the heater control module 302, via the heater control signal, to apply the power to the entire heater element 222 and/or any zone or combination of zones of the heater element 222. The heater control module 302 may include, for example, a driver control module 320 and one or more switching modules, such as switching modules 322, 324, 326, 328, and 330. The switching modules 322-330 may be, for example, transistors. More specifically, the switching modules 322-330 may be power transistors. Each of the zones of the heater element 222 may be connected to one of the switching modules 322-330 and to a return line (not shown) or a common ground (not shown). The driver control module 320 may control the application of power to the zones of the heater element 222 by, for example, controlling the switching modules 322-330. For example only, the driver control module 320 may apply power to: a first zone of the zone arrangement 310, via the switching module 322; a second zone, via the switching module 324; a third zone, via the switching module 326; a fourth zone, via the switching module 328; and a fifth zone, via the switching module 330. The driver control module 320 may control the switching modules 322-330 based upon the control signal from the PCM 304. The PCM 304 may, for example, instruct the driver control module 320 to apply power to each of the zones of the heater element 222 in a predefined order, such as a sequential order. For example only, the sequential order may include applying power to the first zone, then the second zone, then the third zone, then the fourth zone, then the fifth zone. The driver control module 320 may repeat applying power to the zones in this order until a corresponding instruction from the PCM 304 is received. Referring now to FIG. 4, a functional block diagram of an exemplary emissions control system 400 is presented. The emissions control system 400 includes an emissions control module 402 and a temperature determination module 404. In various implementations, the emissions control module 402 and the temperature determination module 404 may be implemented in the PCM 304. The PCM 304 may also include an engine control module 408. Upon starting the engine 104, the emissions control module 402 generates the heater control signal, which instructs the heater control module 302 to activate the heater element 222. The heater control module 302 may repeatedly activate various zones of the heater element 222. The temperature determination module 404 determines the SCR temperature and the heater temperature. Upon starting the diesel engine system 102, the temperature determination module 404 may estimate that the SCR temperature and the heater temperature are a predetermined temperature, such as an ambient temperature. The temperature determination module 404 may determine the heater temperature based upon, for example, the power supplied to the heater control module 302. The temperature determination module 404 may measure the voltage and/or the current supplied to the heater control module 302 in order to determine the power supplied. The power provided to the heater element 222 over time can be used to estimate the temperature of the heater element 222. The emissions control module 402 may determine that combustion may begin when the heater temperature is greater than a temperature threshold, referred to as THEATER. For example only, THEATER may be 250° C. Once the heater temperature is greater than THEATER, the emissions control module 402 may generate an engine control signal. The engine control signal instructs the engine control module 408 to activate a predefined combustion process. The predefined combustion process may provide unburned fuel to the exhaust system 106. For example, the engine control module 408 may increase the amount of fuel injected into the engine 104. In various implementations, fuel may be directly injected into the exhaust system 106. Unburned fuel provided to the exhaust system 106 by the predefined combustion process will be combusted by the heated catalyst coating of the heater element 222. The temperature determination module 404 may estimate the temperature of the substrate 220 or the SCR catalyst based upon, for example, the duration of the predefined combustion process. The temperature determination module 404 may determine the temperature at the substrate 220 and estimate that the SCR temperature is approximately equal to the substrate temperature. Alternatively, the temperature determination module 404 may apply a low-pass filter to the substrate temperature to determine the SCR temperature. In addition, the temperature determination module 404 may estimate that the SCR temperature is a predetermined percentage or amount less than the substrate temperature. In addition, the temperature determination module 404 may receive temperature data from temperature sensors, which may be located near the heater element 222 and/or at other locations in the DPF assembly 116. The temperature data may be used instead of, or as a supplement to, estimation of the substrate and SCR temperatures. The emissions control module 402 may determine that the SCR catalyst will effectively operate once the SCR temperature reaches the TSCR threshold. At this time, the emissions control module 402 may generate a reductant control signal, which instructs the reductant injector 112 to begin injecting reductant into the exhaust. In various implementations, the reductant injector 112 may continue injecting the reductant into the exhaust until the engine 104 is turned off. The emissions control module 402 may also instruct the heater control module 302 to deactivate the heater element 222. In this manner, the emissions control module 402 ensures that the functionality of the SCR catalyst is not compromised by injecting reductant before the SCR temperature reaches the TSCR threshold. Referring now to FIG. 5, a flowchart depicting exemplary steps performed by the emissions control module 402 are presented. Control begins upon starting the vehicle 300. In step 504, control determines the initial SCR temperature and the initial heater temperature. In various implementations, control may assume that the initial SCR temperature and the initial heater temp are equal to a predetermine temperature, such as an ambient temperature. Control continues in step 508 where control determines whether the SCR temperature is greater than the TSCR threshold. If so, control transfers to step 528; otherwise control continues in step 512. In step 512, control activates the heater control module 302. In various implementations, the heater control module 302 repeatedly activates one or more zones of the heater element 222 in the sequential order. Control then continues in step 516 where control determines whether the heater temperature is above the THEATER threshold. If so, control transfers to step 520; otherwise, control continues in step 524. In step 520, control instructs the engine control module 408 to activate the predefined combustion process and control continues in step 524. The predefined combustion process may produce additional fuel in the exhaust of the engine 104. The additional fuel provided by the predefined combustion process is combusted at the heater element 222, thereby warming the SCR catalyst. In step 524, control determines the SCR temperature and the heater temperature, and control returns to step 508. For example, control measures and/or estimates the SCR temperature and the heater temperature. In step 528, control instructs the reductant injector 112 to begin injecting the reductant into the exhaust. Control continues in step 532, where control deactivates the heater element 222 and control ends. Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification, and the following claims.
|
F
|
F01
|
F01N
|
3
|
20
|
|||
11669593
|
US20070163809A1-20070719
|
DRILLING AND HOLE ENLARGEMENT DEVICE
|
ACCEPTED
|
20070703
|
20070719
|
[]
|
E21B1032
|
["E21B1032"]
|
7757787
|
20070131
|
20100720
|
175
|
057000
|
67606.0
|
HARCOURT
|
BRAD
|
[{"inventor_name_last": "Mackay", "inventor_name_first": "Alexander", "inventor_city": "Aberdeen", "inventor_state": "", "inventor_country": "GB"}, {"inventor_name_last": "Espiritu", "inventor_name_first": "George", "inventor_city": "Houston", "inventor_state": "TX", "inventor_country": "US"}, {"inventor_name_last": "Dewey", "inventor_name_first": "Charles", "inventor_city": "Houston", "inventor_state": "TX", "inventor_country": "US"}]
|
An expandable drilling apparatus includes a main body comprising a central bore and at least one axial recess configured to receive an arm assembly operable between a retracted position and an extended position, a biasing member to urge the arm assembly into the retracted position, a drive position configured to thrust the arm assembly into the extended position when in communication with drilling fluids in the central bore, a selector piston translatable between an open position and a closed position, wherein the selector piston is thrust into the open position when a pressure of the drilling fluids exceeds an activation value, wherein the drilling fluids are in communication with the drive piston when the selector piston is in the open position, and a selector spring configured to thrust the selector piston into the closed position when the pressure of the drilling fluids falls below a reset value.
|
1. An expandable drilling apparatus, comprising: a main body comprising a central bore and at least one axial recess configured to receive an arm assembly operable between a retracted position and an extended position; a biasing member to urge the arm assembly into the retracted position; a drive piston configured to thrust the arm assembly into the extended position when in communication with drilling fluids in the central bore; a selector piston translatable between an open position and a closed position, wherein the selector piston is thrust into the open position when a pressure of the drilling fluids exceeds an activation value; wherein the drilling fluids are in communication with the drive piston when the selector piston is in the open position; a selector spring configured to thrust the selector piston into the closed position when the pressure of the drilling fluids falls below a reset value. 2. The expandable drilling apparatus of claim 1, wherein the arm assembly translates along a plurality of grooves formed into walls of the axial recess. 3. The expandable drilling apparatus of claim 1, further comprising a cutting head adjacent to a distal end of the main body. 4. The expandable drilling apparatus of claim 3, wherein the cutting head comprises a drill bit. 5. The expandable drilling apparatus of claim 3, wherein the arm assembly is axially positioned behind the cutting head a distance between about one to about five times a diameter of the cutting head. 6. The expandable drilling apparatus of claim 1, wherein the arm assembly translates along a plurality of grooves formed on sides of the arm assembly. 7. The expandable drilling apparatus of claim 1, wherein the arm assembly comprises cutting elements configured to underream a pilot bore. 8. The expandable drilling apparatus of claim 1, wherein the arm assembly comprises a stabilizer portion. 9. The expandable drilling apparatus of claim 1, further comprising a shear member to retain the selector piston in the closed position. 10. The expandable drilling apparatus of claim 1, wherein the drilling assembly exhibits a first characteristic pressure drop profile when the selector piston is in the closed position and a second characteristic pressure drop profile when the selector piston is in the open position. 11. The expandable drilling apparatus of claim 10, further comprising an third characteristic pressure drop profile when the selector piston is in the open position and the arm assembly is in the extended position. 12. The expandable drilling apparatus of claim 1, wherein the main body is substantially tubular. 13. An expandable drilling apparatus connected to a drillstring, the drilling apparatus comprising: a cutting head disposed upon a main body, wherein the main body comprises a plurality of axial recesses adjacent to the cutting head; a plurality of arm assemblies retained within the axial recesses, wherein the arm assemblies are configured to translate from a retracted position to an extended position along a plurality of grooves formed into walls of the axial recesses; a drive piston configured to thrust the arm assemblies into the extended position when in communication with fluids flowing through the drillstring; and a selector piston configured to allow fluids flowing through the drillstring to communicate with the drive piston when an activation pressure is exceeded. 14. The expandable drilling apparatus of claim 13, wherein the arm assemblies are axially positioned behind the cutting head a distance between one to five times a diameter of the cutting head. 15. The expandable drilling apparatus of claim 13, wherein the expandable drilling apparatus exhibits a first characteristic pressure drop profile when selector piston isolates fluids flowing through the drillstring from the drive piston, and a second characteristic pressure drop profile when the selector piston allows fluids flowing through the drillstring to communicate with the drive piston. 16. The expandable drilling apparatus of claim 15, wherein the expandable drilling apparatus exhibits a third characteristic pressure drop profile when the plurality of arm assemblies are in the extended position. 17. A method of drilling a borehole comprising: disposing a drilling assembly having expandable arm assemblies adjacent to a cutting head upon a distal end of a drillstring; drilling a pilot bore with the cutting head; underreaming the pilot bore with cutting elements of the expandable arm assemblies; stabilizing the drilling assembly with stabilizer pads of the expandable arm assemblies. 18. The method of claim 17, further comprising: retracting the expandable arm assemblies; and drilling the pilot bore with the expandable arm assemblies in a retracted position. 19. The method of claim 17, further comprising a flex joint member between the expandable arm assemblies and the drillstring. 20. The method of claim 19, further comprising using the cutting head and the expandable arm assemblies as a single fulcrum point in a directional drilling operation.
|
<SOH> BACKGROUND <EOH>1. Field of the Disclosure The present disclosure generally relates to drilling apparatus and methods. More particularly, the present disclosure relates to methods and apparatus to drill and underream subterranean wellbores. More particularly still, the present disclosure relates to methods and apparatus to drill and underream a subterranean wellbore with selectively retractable and extendable arm assemblies. 2. Background Art In the drilling of oil and gas wells, typically concentric casing strings are installed and cemented in the borehole as drilling progresses to increasing depths. Each new casing string is supported within the previously installed casing string, thereby limiting the annular area available for the cementing operation. Further, as successively smaller diameter casing strings are suspended, the flow area for the production of oil and gas is reduced. Therefore, to increase the annular space for the cementing operation, and to increase the production flow area, it is often desirable to enlarge the borehole below the terminal end of the previously cased borehole. By enlarging the borehole, a larger annular area is provided for subsequently installing and cementing a larger casing string than would have been possible otherwise. Accordingly, by enlarging the borehole below the previously cased borehole, the bottom of the formation can be reached with comparatively larger diameter casing, thereby providing more flow area for the production of oil and gas. Various methods have been devised for passing a drilling assembly through a cased borehole, or in conjunction with expandable casing to enlarging the borehole. One such method involves the use of an underreamer, which has basically two operative states--a closed or collapsed state, where the diameter of the tool is sufficiently small to allow the tool to pass through the existing cased borehole, and an open or partly expanded state, where one or more arms with cutters on the ends thereof extend from the body of the tool. In this latter position, the underreamer enlarges the borehole diameter as the tool is rotated and lowered in the borehole. A “drilling type” underreamer is one that is typically used in conjunction with a conventional “pilot” drill bit positioned below (i.e. downstream of) the underreamer. Typically, the pilot bit drills the borehole to a reduced gauge, while the underreamer, positioned behind the pilot bit, simultaneously enlarges the pilot borehole to full gauge. Formerly, underreamers of this type had hinged arms with roller cone cutters attached thereto. Typical former underreamers included swing out cutter arms that pivoted at an end opposite the cutting end of the cutting arms, with the cutter arms actuated by mechanical or hydraulic forces acting on the arms to extend or retract them. Representative examples of these types of underreamers are found in U.S. Pat. Nos. 3,224,507; 3,425,500 and 4,055,226, all incorporated by reference herein. In some former designs, the pivoted arms could break and fall free of the underreamer during the drilling operation, thereby necessitating a costly and time consuming “fishing” operation to retrieve them from the borehole before drilling could continue. Accordingly, prior art underreamers may not be capable of underreaming harder rock formations, may have unacceptably slow rates of penetration, or their constructed geometries may not be capable of handling high fluid flow rates. The vacant pocket recesses also tend to fill with debris while the cutters are extended, thereby hindering the desired collapse of the arms at the conclusion of the operation. If the arms do not fully collapse, the drill string may hang up when a trip out of the borehole is attempted. Furthermore, conventional underreamers include cutting structures that are typically formed of sections of drill bits rather than being specifically designed for the underreaming function, As a result, the cutting structures of most underreamers do not reliably underream the borehole to the desired gauge diameter. Also, adjusting the expanded diameter of a conventional underreamer requires replacement of the cutting arms with larger or smaller arms, or replacement of other components of the underreamer tool. It may even be necessary to replace the underreamer altogether with one that provides a different expanded diameter. Moreover, many underreamers are constructed to expand when drilling fluid is pumped through the drill string at elevated pressures with no indication that the tool is in the fully expanded position. Furthermore, many expandable downhole tools expand from a retracted state to an extended state through the rupture of a shear member within the tool. Consequently, once the shear member is ruptured, pressurized fluid flow through the tool will bias the cutting arms toward expansion. As such, a return to the “original” operating state whereby the cutting arms remain retracted at pressures below the rupture pressure is no longer possible. Therefore, it would be advantageous for a drilling operator to have the ability to control not only when the underreamer expands and retracts, but also have the ability to know the status of such expansion. Another method for enlarging a borehole below a previously cased borehole section involves the use of a winged reamer behind a conventional drill bit. In such an assembly, a conventional pilot drill bit is disposed at the distal end of the drilling assembly with the winged reamer disposed at some distance behind the drill bit. The winged reamer generally comprises a tubular body with one or more longitudinally extending “wings” or blades projecting radially outward from the tubular body. Once the winged reamer passes through any cased portions of the wellbore, the pilot bit rotates about the centerline of the drilling axis to drill a lower borehole on center in the desired trajectory of the well path, while the eccentric winged reamer follows the pilot bit and engages the formation to enlarge the pilot borehole to the desired diameter. Yet another method for enlarging a borehole below a previously cased borehole section includes using a bi-center bit, which is a one-piece drilling structure that provides a combination underreamer and pilot bit. The pilot bit is disposed on the lowermost end of the drilling assembly, and the eccentric underreamer bit is disposed slightly above the pilot bit. Once the bi-center bit passes through any cased portions of the wellbore, the pilot bit rotates about the centerline of the drilling axis and drills a pilot borehole on center in the desired trajectory of the well path, while the eccentric underreamer bit follows the pilot bit engaging the formation to enlarge the pilot borehole to the desired final gauge. The diameter of the pilot bit is made as large as possible for stability while still being capable of passing through the cased borehole. Examples of bi-center bits may be found in U.S. Pat. Nos. 6,039,131 and 6,269,893, all incorporated by reference herein. As described above, winged reamers and bi-center bits each include eccentric underreamer portions. Because of this design, off-center drilling is required to drill out the cement and float equipment to ensure that the eccentric underreamer portions do not damage the casing. Accordingly, it is desirable to provide an underreamer that collapses while the drilling assembly is in the casing and that expands to underream the previously drilled borehole to the desired diameter below the casing. Further, due to directional tendency problems, these eccentric underreamer portions have difficulty reliably underreaming the borehole to the desired gauge diameter. With respect to a bi-center bit, the eccentric underreamer bit tends to cause the pilot bit to wobble and undesirably deviate off center, thereby pushing the pilot bit away from the preferred trajectory of the wellbore. A similar problem is experienced with winged reamers, which are only capable of underreaming the borehole to the desired gauge if the pilot bit remains centralized in the borehole during drilling. Accordingly, it is desirable to provide an underreamer that remains concentrically disposed within the borehole while underreaming the previously drilled borehole to the desired gauge diameter. Furthermore, it is conventional to employ a tool known as a “stabilizer” in drilling operations. In standard boreholes, traditional stabilizers are located in the drilling assembly behind the drill bit to control and maintain the trajectory of the drill bit as drilling progresses. Traditional stabilizers control drilling in a desired direction, whether the direction is along a straight borehole or a deviated borehole. In a conventional rotary drilling assembly, a drill bit may be mounted onto a lower stabilizer, which may be disposed approximately 5 or more feet above the bit. Typically the lower stabilizer is a fixed blade stabilizer and includes a plurality of concentric blades extending radially outwardly and azimuthally spaced around the circumference of the stabilizer housing. The outer edges of the blades are adapted to contact the wall of the existing cased borehole, thereby defining the maximum stabilizer diameter that will pass through the casing. A plurality of drill collars extends between the lower and other stabilizers in the drilling assembly. An upper stabilizer is typically positioned in the drill sting approximately 30-60 feet above the lower stabilizer. There could also be additional stabilizers above the upper stabilizer. The upper stabilizer may be either a fixed blade stabilizer or, more recently, an adjustable blade stabilizer capable of allowing its blades to collapse into the housing as the drilling assembly passes through the narrow gauge casing and subsequently expand in the borehole below. One type of adjustable concentric stabilizer is manufactured by Andergauge U.S.A., Inc., Spring, Tex. and is described in U.S. Pat. No. 4,848,490. Another type of adjustable concentric stabilizer is manufactured by Halliburton, Houston, Tex. and is described in U.S. Pat. Nos. 5,318,137, 5,318,138, and 5,332,048. In operation, if only the lower stabilizer is provided, a “fulcrurm” effect may occur because gravity displaces the lower stabilizer such that it acts as a fulcrum or pivot point for the bottom hole assembly. Alternatively, in rotary steerable and positive displacement mud motor applications, the fulcrum effect may also result from the bending loads transferred across the lower stabilizer from a directional mechanism. Namely, as drilling progresses in a deviated borehole, for example, the weight of the drill collars behind the lower stabilizer forces the stabilizer to push against the lower side of the borehole, thereby creating a fulcrum or pivot point for the drill bit. Accordingly, the drill bit tends to be lifted upwardly at a trajectory known as the build angle. Therefore, a second stabilizer is provided to offset the fulcrum effect. As the drill bit builds due to the fulcrum effect created by the lower stabilizer, the upper stabilizer engages the lower side of the borehole, thereby causing the longitudinal axis of the bit to pivot downwardly so as to drop angle. A radial change of the blades of the upper stabilizer can control the pivoting of the bit on the lower stabilizer, thereby providing a two-dimensional, gravity based steerable system to control the build or drop angle of the drilled borehole as desired.
|
<SOH> SUMMARY OF DISCLOSURE <EOH>According to one aspect of the present disclosure, an expandable drilling apparatus includes a main body comprising a central bore and at least one axial recess configured to receive an arm assembly operable between a retracted position and an extended position. The expandable drilling apparatus also includes a biasing member to urge the arm assembly into the retracted position and a drive piston configured to thrust the arm assembly into the extended position when in communication with drilling fluids in the central bore. Furthermore, the expandable drilling apparatus includes a selector piston translatable between an open position and a closed position, wherein the selector piston is thrust into the open position when a pressure of the drilling fluids exceeds an activation value, wherein the drilling fluids are in communication with the drive piston when the selector piston is in the open position. Furthermore, the expandable drilling apparatus includes a selector spring configured to thrust the selector piston into the closed position when the pressure of the drilling fluids falls below a reset value. According to another aspect of the present disclosure, an expandable drilling apparatus connected to a drillstring includes a cutting head disposed upon a main body, wherein the main body comprises a plurality of axial recesses adjacent to the cutting head. Further, the expandable drilling apparatus includes a plurality of arm assemblies retained within the axial recesses, wherein the arm assemblies are configured to translate from a retracted position to an extended position along a plurality of grooves formed into walls of the axial recesses, a drive piston configured to thrust the arm assemblies into the extended position when in communication with fluids flowing through the drillstring, and a selector piston configured to allow fluids flowing through the drillstring to communicate with the drive piston when an activation pressure is exceeded. According to another aspect of the present disclosure, a method to drill a borehole including disposing a drilling assembly having expandable arm assemblies adjacent to a cutting head upon a distal end of a drillstring, drilling a pilot bore with the cutting head, underreaming the pilot bore with cutting elements of the expandable arm assemblies, stabilizing the drilling assembly with stabilizer pads of the expandable arm assemblies.
|
CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a Continuation-In-Part of pending U.S. patent application Ser. No. 11/334,195, filed Jan. 18, 2006. BACKGROUND 1. Field of the Disclosure The present disclosure generally relates to drilling apparatus and methods. More particularly, the present disclosure relates to methods and apparatus to drill and underream subterranean wellbores. More particularly still, the present disclosure relates to methods and apparatus to drill and underream a subterranean wellbore with selectively retractable and extendable arm assemblies. 2. Background Art In the drilling of oil and gas wells, typically concentric casing strings are installed and cemented in the borehole as drilling progresses to increasing depths. Each new casing string is supported within the previously installed casing string, thereby limiting the annular area available for the cementing operation. Further, as successively smaller diameter casing strings are suspended, the flow area for the production of oil and gas is reduced. Therefore, to increase the annular space for the cementing operation, and to increase the production flow area, it is often desirable to enlarge the borehole below the terminal end of the previously cased borehole. By enlarging the borehole, a larger annular area is provided for subsequently installing and cementing a larger casing string than would have been possible otherwise. Accordingly, by enlarging the borehole below the previously cased borehole, the bottom of the formation can be reached with comparatively larger diameter casing, thereby providing more flow area for the production of oil and gas. Various methods have been devised for passing a drilling assembly through a cased borehole, or in conjunction with expandable casing to enlarging the borehole. One such method involves the use of an underreamer, which has basically two operative states--a closed or collapsed state, where the diameter of the tool is sufficiently small to allow the tool to pass through the existing cased borehole, and an open or partly expanded state, where one or more arms with cutters on the ends thereof extend from the body of the tool. In this latter position, the underreamer enlarges the borehole diameter as the tool is rotated and lowered in the borehole. A “drilling type” underreamer is one that is typically used in conjunction with a conventional “pilot” drill bit positioned below (i.e. downstream of) the underreamer. Typically, the pilot bit drills the borehole to a reduced gauge, while the underreamer, positioned behind the pilot bit, simultaneously enlarges the pilot borehole to full gauge. Formerly, underreamers of this type had hinged arms with roller cone cutters attached thereto. Typical former underreamers included swing out cutter arms that pivoted at an end opposite the cutting end of the cutting arms, with the cutter arms actuated by mechanical or hydraulic forces acting on the arms to extend or retract them. Representative examples of these types of underreamers are found in U.S. Pat. Nos. 3,224,507; 3,425,500 and 4,055,226, all incorporated by reference herein. In some former designs, the pivoted arms could break and fall free of the underreamer during the drilling operation, thereby necessitating a costly and time consuming “fishing” operation to retrieve them from the borehole before drilling could continue. Accordingly, prior art underreamers may not be capable of underreaming harder rock formations, may have unacceptably slow rates of penetration, or their constructed geometries may not be capable of handling high fluid flow rates. The vacant pocket recesses also tend to fill with debris while the cutters are extended, thereby hindering the desired collapse of the arms at the conclusion of the operation. If the arms do not fully collapse, the drill string may hang up when a trip out of the borehole is attempted. Furthermore, conventional underreamers include cutting structures that are typically formed of sections of drill bits rather than being specifically designed for the underreaming function, As a result, the cutting structures of most underreamers do not reliably underream the borehole to the desired gauge diameter. Also, adjusting the expanded diameter of a conventional underreamer requires replacement of the cutting arms with larger or smaller arms, or replacement of other components of the underreamer tool. It may even be necessary to replace the underreamer altogether with one that provides a different expanded diameter. Moreover, many underreamers are constructed to expand when drilling fluid is pumped through the drill string at elevated pressures with no indication that the tool is in the fully expanded position. Furthermore, many expandable downhole tools expand from a retracted state to an extended state through the rupture of a shear member within the tool. Consequently, once the shear member is ruptured, pressurized fluid flow through the tool will bias the cutting arms toward expansion. As such, a return to the “original” operating state whereby the cutting arms remain retracted at pressures below the rupture pressure is no longer possible. Therefore, it would be advantageous for a drilling operator to have the ability to control not only when the underreamer expands and retracts, but also have the ability to know the status of such expansion. Another method for enlarging a borehole below a previously cased borehole section involves the use of a winged reamer behind a conventional drill bit. In such an assembly, a conventional pilot drill bit is disposed at the distal end of the drilling assembly with the winged reamer disposed at some distance behind the drill bit. The winged reamer generally comprises a tubular body with one or more longitudinally extending “wings” or blades projecting radially outward from the tubular body. Once the winged reamer passes through any cased portions of the wellbore, the pilot bit rotates about the centerline of the drilling axis to drill a lower borehole on center in the desired trajectory of the well path, while the eccentric winged reamer follows the pilot bit and engages the formation to enlarge the pilot borehole to the desired diameter. Yet another method for enlarging a borehole below a previously cased borehole section includes using a bi-center bit, which is a one-piece drilling structure that provides a combination underreamer and pilot bit. The pilot bit is disposed on the lowermost end of the drilling assembly, and the eccentric underreamer bit is disposed slightly above the pilot bit. Once the bi-center bit passes through any cased portions of the wellbore, the pilot bit rotates about the centerline of the drilling axis and drills a pilot borehole on center in the desired trajectory of the well path, while the eccentric underreamer bit follows the pilot bit engaging the formation to enlarge the pilot borehole to the desired final gauge. The diameter of the pilot bit is made as large as possible for stability while still being capable of passing through the cased borehole. Examples of bi-center bits may be found in U.S. Pat. Nos. 6,039,131 and 6,269,893, all incorporated by reference herein. As described above, winged reamers and bi-center bits each include eccentric underreamer portions. Because of this design, off-center drilling is required to drill out the cement and float equipment to ensure that the eccentric underreamer portions do not damage the casing. Accordingly, it is desirable to provide an underreamer that collapses while the drilling assembly is in the casing and that expands to underream the previously drilled borehole to the desired diameter below the casing. Further, due to directional tendency problems, these eccentric underreamer portions have difficulty reliably underreaming the borehole to the desired gauge diameter. With respect to a bi-center bit, the eccentric underreamer bit tends to cause the pilot bit to wobble and undesirably deviate off center, thereby pushing the pilot bit away from the preferred trajectory of the wellbore. A similar problem is experienced with winged reamers, which are only capable of underreaming the borehole to the desired gauge if the pilot bit remains centralized in the borehole during drilling. Accordingly, it is desirable to provide an underreamer that remains concentrically disposed within the borehole while underreaming the previously drilled borehole to the desired gauge diameter. Furthermore, it is conventional to employ a tool known as a “stabilizer” in drilling operations. In standard boreholes, traditional stabilizers are located in the drilling assembly behind the drill bit to control and maintain the trajectory of the drill bit as drilling progresses. Traditional stabilizers control drilling in a desired direction, whether the direction is along a straight borehole or a deviated borehole. In a conventional rotary drilling assembly, a drill bit may be mounted onto a lower stabilizer, which may be disposed approximately 5 or more feet above the bit. Typically the lower stabilizer is a fixed blade stabilizer and includes a plurality of concentric blades extending radially outwardly and azimuthally spaced around the circumference of the stabilizer housing. The outer edges of the blades are adapted to contact the wall of the existing cased borehole, thereby defining the maximum stabilizer diameter that will pass through the casing. A plurality of drill collars extends between the lower and other stabilizers in the drilling assembly. An upper stabilizer is typically positioned in the drill sting approximately 30-60 feet above the lower stabilizer. There could also be additional stabilizers above the upper stabilizer. The upper stabilizer may be either a fixed blade stabilizer or, more recently, an adjustable blade stabilizer capable of allowing its blades to collapse into the housing as the drilling assembly passes through the narrow gauge casing and subsequently expand in the borehole below. One type of adjustable concentric stabilizer is manufactured by Andergauge U.S.A., Inc., Spring, Tex. and is described in U.S. Pat. No. 4,848,490. Another type of adjustable concentric stabilizer is manufactured by Halliburton, Houston, Tex. and is described in U.S. Pat. Nos. 5,318,137, 5,318,138, and 5,332,048. In operation, if only the lower stabilizer is provided, a “fulcrurm” effect may occur because gravity displaces the lower stabilizer such that it acts as a fulcrum or pivot point for the bottom hole assembly. Alternatively, in rotary steerable and positive displacement mud motor applications, the fulcrum effect may also result from the bending loads transferred across the lower stabilizer from a directional mechanism. Namely, as drilling progresses in a deviated borehole, for example, the weight of the drill collars behind the lower stabilizer forces the stabilizer to push against the lower side of the borehole, thereby creating a fulcrum or pivot point for the drill bit. Accordingly, the drill bit tends to be lifted upwardly at a trajectory known as the build angle. Therefore, a second stabilizer is provided to offset the fulcrum effect. As the drill bit builds due to the fulcrum effect created by the lower stabilizer, the upper stabilizer engages the lower side of the borehole, thereby causing the longitudinal axis of the bit to pivot downwardly so as to drop angle. A radial change of the blades of the upper stabilizer can control the pivoting of the bit on the lower stabilizer, thereby providing a two-dimensional, gravity based steerable system to control the build or drop angle of the drilled borehole as desired. SUMMARY OF DISCLOSURE According to one aspect of the present disclosure, an expandable drilling apparatus includes a main body comprising a central bore and at least one axial recess configured to receive an arm assembly operable between a retracted position and an extended position. The expandable drilling apparatus also includes a biasing member to urge the arm assembly into the retracted position and a drive piston configured to thrust the arm assembly into the extended position when in communication with drilling fluids in the central bore. Furthermore, the expandable drilling apparatus includes a selector piston translatable between an open position and a closed position, wherein the selector piston is thrust into the open position when a pressure of the drilling fluids exceeds an activation value, wherein the drilling fluids are in communication with the drive piston when the selector piston is in the open position. Furthermore, the expandable drilling apparatus includes a selector spring configured to thrust the selector piston into the closed position when the pressure of the drilling fluids falls below a reset value. According to another aspect of the present disclosure, an expandable drilling apparatus connected to a drillstring includes a cutting head disposed upon a main body, wherein the main body comprises a plurality of axial recesses adjacent to the cutting head. Further, the expandable drilling apparatus includes a plurality of arm assemblies retained within the axial recesses, wherein the arm assemblies are configured to translate from a retracted position to an extended position along a plurality of grooves formed into walls of the axial recesses, a drive piston configured to thrust the arm assemblies into the extended position when in communication with fluids flowing through the drillstring, and a selector piston configured to allow fluids flowing through the drillstring to communicate with the drive piston when an activation pressure is exceeded. According to another aspect of the present disclosure, a method to drill a borehole including disposing a drilling assembly having expandable arm assemblies adjacent to a cutting head upon a distal end of a drillstring, drilling a pilot bore with the cutting head, underreaming the pilot bore with cutting elements of the expandable arm assemblies, stabilizing the drilling assembly with stabilizer pads of the expandable arm assemblies. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a sectioned view of a drilling assembly in a retracted position in accordance with an embodiment of the present disclosure. FIG. 1A is a close-up view of a portion of the drilling assembly of FIG. 1. FIG. 2 is an end view drawing of the drilling assembly of FIG. 1. FIG. 3 is an alternative sectioned view of a portion of the drilling assembly of FIG. 1. FIG. 4 is a close-up detail view of a lower portion of a flow switch of the drilling assembly of FIG. 1. FIG. 5 is a close-up detail view of an extension assembly of the drilling assembly of FIG. 1. FIG. 6 is a cross-sectional view of the drilling assembly of FIG. 1 taken at 6-6. FIG. 7 is a cross-sectional view of the drilling assembly of FIG. 1 taken at 7-7. FIG. 8 is a cross-sectional view of the drilling assembly of FIG. 1 taken at 8-8. FIG. 9 is a cross-sectional view of the drilling assembly of FIG. 1 taken at 9-9. FIG. 10 is a cross-sectional view of the drilling assembly of FIG. 1 taken at 10-10. FIG. 11 is a sectioned view drawing of the drilling assembly of FIG. 1 in a fully extended position. FIG. 12 is an isometric view of the drilling assembly of FIG. 1 in the fully extended position. FIG. 13 is an exploded isometric view of the extension assembly of FIGS. 1 and 11. FIG. 14 is an isometric view of an arm assembly of the drilling assembly of FIGS. 1 and 11. FIG. 15 is a cross-sectional view of the drilling assembly of FIG. 11 taken at 15-15. FIG. 16 is a cross-sectional view of the drilling assembly of FIG. 11 taken at 16-16. FIG. 17 is a cross-sectional view of a first alternative arm assembly extension mechanism in a retracted position in accordance with an embodiment of the present disclosure. FIG. 18 is a cross-sectional view of the extension mechanism of FIG. 18 in an extended position. FIG. 19 is a cross-sectional view of a second alternative arm assembly extension mechanism in a retracted position in accordance with an embodiment of the present disclosure. FIG. 20 is a cross-sectional view of the extension mechanism of FIG. 19 in an extended position. FIG. 21 is a profile view of a drilling assembly in an accordance with an alternative embodiment of the present disclosure in a retracted position. FIG. 22 is a profile view of the drilling assembly of FIG. 21 in an extended position. FIG. 23 is partial section-view drawings of the drilling assembly of FIG. 21. FIG. 24 is a section-view drawing of the drilling assembly of FIG. 21 detailing fluid flow. DETAILED DESCRIPTION Embodiments disclosed herein generally relate to a drilling assemblies used in subterranean drilling. More particularly, certain embodiments disclose drilling assemblies that include a pilot bit portion and an expandable underreamer/stabilizer portion within close axial proximity to one another to simultaneously underream a pilot bore. Further, selected embodiments disclose a flow switch to actuate the expansion of the expandable underreamer/stabilizer portion, such that an operator may discern with an increased degree of accuracy whether the drilling assembly is fully expanded or retracted. Further, selected embodiments disclose an expandable drilling assembly capable of being reset to its original condition following expansion while remaining downhole. Furthermore, selected embodiments disclose an arrangement for an expandable stabilizer/cutter assembly wherein the cutter assembly is capable of expanding into the formation ahead of the stabilizer. U.S. Pat. No. 6,732,812, incorporated by reference in its entirety herein, discloses an expandable downhole tool for use in a drilling assembly positioned within a wellbore. Referring now to FIG. 1, a drilling assembly 50 in accordance with an embodiment disclosed herein is shown. Drilling assembly 50 is shown having a substantially tubular main body 52, a cutting head 54, a flex member 55, and a drillstring connection 56. While drillstring connection 56 is depicted as a rotary threaded connection, it should be understood by one of ordinary skill in the art that any method of connecting drilling assembly 50 with the remainder of the drillstring (not shown) may be employed, so long as rotational and axial loads may be transmitted therethrough. It should be understood that the term “drillstring” may be used to describe any apparatus or assembly that may be used to thrust and rotate drilling assembly 50. Particularly, the drillstring may comprise mud motors, bent subs, rotary steerable systems, drill pipe rotated from the surface, coiled tubing or any other drilling mechanism known to one of ordinary skill. Furthermore, it should be understood that the drillstring may include additional components (e.g. MWD/LWD tools, stabilizers, and weighted drill collars, etc.) as needed to perform various downhole tasks. Cutting head 54 is depicted with a cutting structure 58 including a plurality of polycrystalline diamond compact (“PDC”) cutters 60 and fluid nozzles 62. While drilling assembly 50 depicts a PDC cutting head 54, it should be understood that any cutting assembly known to one of ordinary skill in the art, including, but not limited to, roller-cone bits and impregnated natural diamond bits, may be used. As drilling assembly 50 is rotated and thrust into the formation, cutters 60 scrape and gouge away at the formation while fluid nozzles 62 cool, lubricate, and wash cuttings away from cutting structure 58. Additionally, tubular main body 52 includes a plurality of axial recesses 64 into which arm assemblies 66 are located. Arm assemblies 66 are configured to extend from a retracted (shown) position to an extended position (FIG. 11) when cutting elements 68 and stabilizer pads 70 of arm assemblies are to be engaged with the formation. Arm assemblies 66 travel from their retracted position to their extended position along a plurality of grooves 72 within the wall of axial recesses 64. Corresponding grooves (73 of FIG. 14) along the outer profile of arm assemblies 66 engage grooves 72 and guide arm assemblies 66 as they traverse in and out of axial recesses 64. While three arm assemblies 66 are depicted in figures of the present disclosure, it should be understood that any number of arm assemblies 66 may be employed, from a single arm assembly 66 to as many arm assemblies 66 as the size and geometry of main body 52 may accommodate. Furthermore, while each arm assembly 66 is depicted with both stabilizer pads 70 and cutting elements 68, it should be understood that arm assemblies 66 may include stabilizer pads 70, cutting elements 68, or a combination thereof in any proportion appropriate for the type of operation to be performed. Additionally, arm assembly 66 may include various sensors, measurement devices, or any other type of equipment desirably retractable and extendable from and against the borehole upon demand. In operation, cutting structure 58 upon cutting head 54 is designed and sized to cut a pilot bore, or a bore that is large enough to allow drilling assembly 50 in its retracted (FIG. 1) state and remaining components of the drillstring to pass therethrough. In circumstances where the borehole is to be extended below a string of casing, the geometry and size of cutting structure 58 and main body 52 is such that entire drilling assembly 50 may pass clear of the casing string without becoming stuck. Once clear of the casing string or when a larger diameter borehole is desired, arm assemblies 66 are extended and cutting elements 68 disposed thereupon (in conjunction with stabilizer pads 70) underream the pilot bore to the final gauge diameter. As disclosed, drilling assembly 50 uses hydraulic energy to extend arm assemblies 66 from and into axial recesses 64 within main body 52. Drilling fluid is a necessary component of virtually all drilling operations and is delivered downhole from the surface at elevated pressures through a bore of the drillstring. Similarly, drilling assembly 50 includes a through bore 74, through which drilling fluids flow through drillstring connection 56 and main body 52 and out fluid nozzles 62 of cutting head 54 to lubricate cutters 60. As with other downhole drilling devices, the fluid exiting the bore at the bottom of the drillstring returns to the surface along an annulus formed between the borehole and the outer profile of the drillstring and any tools attached thereto. Because of flow restrictions and differential areas between the bore and the annulus of drillstring components, the annulus return pressure may be significantly lower than the bore supply pressure. This differential pressure between the bore and annulus is referred to as the pressure drop across the drillstring. Therefore, for every drillstring configuration, a characteristic pressure drop exists that may be measured and monitored at the surface. As such, if leaks in drill pipe connections, changes in the drillstring flowpath, or clogs within fluid pathways emerge, an operator monitoring the drillstring pressure drop from the surface will notice a change and may take action if necessary. Similarly, drilling assembly 50 will desirably exhibit characteristic pressure drop profiles at various stages of operation downhole. When drilling with arm assemblies 66 in their retracted state within axial recesses 64, drilling assembly 50 will exhibit a pressure drop profile corresponding to that retracted state. When the operator desires to extend arm assemblies 66, the pressure and/or flow rate of drilling fluids flowing through bore 74 are increased to exceed a predetermined activation level. Once the activation level is exceeded, a flow switch activates a mechanism that will extend arm assemblies 66. Following such activation, a portion of the drilling fluids are diverted from through bore 74 of main body 52 to the annulus through a plurality of nozzles 76 located adjacent to axial recesses 64. As drilling fluids begin flowing through nozzles 76, the characteristic pressure drop of drilling assembly 50 changes to an intermediate profile such that the operator at the surface is aware the flow switch is activated and underreaming has begun. Once arm assemblies 66 are fully extended, drilling assembly 50 is desirably constructed such that additional flow through an indication nozzle (77 of FIG. 3) results and another pressure drop profile corresponding to the extended state is exhibited. When the drilling assembly 50 exhibits the expanded characteristic pressure drop profile, an operator monitoring at the surface is aware that arm assemblies 66 have fully extended. Additionally, it is desirable that the intermediate pressure drop profile of drilling fluids remains constant throughout the extension of arm assemblies, such that the surface operator observes a step-plateau change in pressure drop profile for drilling assembly 50. When retraction of arm assemblies 66 is desired, the operator reduces (or completely cuts off) the pressure and/or flow rate of drilling fluids through bore 74 to a level below a predetermined reset level. Once decreased to the reset level, internal biasing mechanisms retract arm assemblies 66 and shut off flow between bore 74 and nozzles 76 and 77. Alternatively, the flow of drilling fluids through bore 74 may be cut off altogether. Following retraction, flow through nozzles 76 is halted and the operator may again observe the characteristic pressure drop profile associated with the retracted state across drilling assembly 50 and know that arm assemblies 66 are fully retracted. As with the extension process, an intermediate pressure drop profile will be observed while arm assemblies 66 are in the process of retracting, but not fully retracted. Once the operator observes the “retracted” characteristic pressure drop, they may proceed to raise the pressure and/or flow rate of drilling fluids through drilling assembly 50 up to the activation level without concern for extending arm assemblies 66. Former flow switch mechanisms, particularly those employing shear members, do not have the ability to return to their original state following activation. As such, devices (e.g., expandable reamers, stabilizers, and drill bits) employing such mechanisms must be returned to the surface for re-configuration before they may be used up to their activation levels again without undesired activation of their components. Specifically, in the case of shear members, once ruptured, they must be replaced as they may be re-activated with even minimal pressure flows therethrough extending their components. Therefore, in circumstances where pressures are accidentally raised above the activation level, the device must be retrieved and re-manufactured before operations may continue at pressure without extension. In contrast, flow switches in accordance with embodiments disclosed herein allow the operator to back off pressure and let the device reset itself, thereby saving costly hours and expense to the drilling contactor. Once reset, elevated pressure flows will not affect arm assemblies 66 until the activation level is again exceeded. Referring generally to FIGS. 1-10, an embodiment of drilling assembly 50 will be described in further detail. In FIG. 1A, a close up view of the distal end of drilling assembly 50 detailing a flow switch 80 is shown. FIG. 2 is an end view drawing of the distal end of drilling assembly 50 indicating the sectional view of FIGS. 1 and 1A at line 1-1. Similarly, FIG. 3 is an alternative sectional view of the distal end of drilling assembly 50 taken along line 3-3 of FIG. 2. FIG. 4 is an enlarged view of a portion of flow switch 80 of drilling assembly indicated by item 4 on FIGS. 1 and 1A. FIG. 5 is an enlarged view of a portion of drilling assembly indicated by item S on FIGS. 1 and 1A. FIG. 6 is a sectional view of drilling assembly 50 taken at line 6-6 in FIGS. 1 and 1A. FIG. 7 is a sectional view of drilling assembly 50 taken at line 7-7 in FIGS. 1 and 1A. FIG. 8 is a sectional view of drilling assembly 50 taken at line 8-8 in FIGS. 1 and 1A. FIG. 9 is a sectional view of drilling assembly 50 taken at line 9-9 in FIGS. 1 and 1A. FIG. 10 is a sectional view of drilling assembly 50 taken at line 10-10 in FIGS. 1 and 1A. Referring now to FIGS. 1, 1A, 3, 4, 6, and 8-10 together, flow switch 80 includes a flow mandrel 82, a nozzle 84, and a piston 86. Mandrel 82 is housed within through bore 74 of main body 52, includes a central bore 78, and is anchored in place at its proximal end by a lock nut 88 in combination with a spring retainer 90. A spring 92 surrounds mandrel 82 and extends from spring retainer 90 to a spring sleeve 94. Spring sleeve 94 is connected at its distal end to a spring drive ring 96 positioned circumferentially around mandrel 82. Spring drive ring 96 includes a plurality of radial yoke-like extensions 98 engaged within arm assemblies 66. As such, when arm assemblies 66 are translated along grooves 72 in wall of axial recesses 64, radial extensions 98 and spring drive ring 96 thrust spring sleeve 94 upstream toward spring retainer 90, compressing spring 92 in the process. Yoke-like construction enables spring drive ring 96 to be located underneath and within arm assemblies 66, thereby conserving axial length of drilling assembly 50. When arm assemblies 66 are fully extended, an arm stop ring 99 prevents over-extension. Therefore, when a force thrusting arm assemblies 66 into engagement is removed, compressed spring 92 in conjunction with spring sleeve 94, drive ring 96 and radial extensions 98 return arm assemblies 66 to their retracted (shown), equilibrium state. Referring specifically to FIGS. 1A, 3, 4, 8, and 9, flow switch 80 includes a flow tube 100 slidably engaged within the distal end of mandrel 82 and a proximal end of a piston stop 102. Flow tube 100 includes nozzle 84 at its proximal end and abuts a spring 104 at its distal end. Spring 104 extends within piston stop 102 from flow tube 100 to a spring retainer 106 that is slidably engaged within piston stop 102 between a steady state position (shown) and a stop ring 108. Toggles 110 pivotally secured to piston stop 102, rotate about hinge pins 112. Toggles 110 prevent spring retainer 106 from sliding within piston stop 102 until piston 86 moves from its retracted (shown) state to its extended state as a result of increases in hydraulic fluid pressure thereagainst. To accomplish this, inward ends 113 of toggles 110 are positioned within apertures 114 of spring retainer 106 and outward ends 116 of toggles engage the end of piston 86 as shown in FIG. 4. With piston 86 fully retracted, toggles 110 are unable to pivot about pins 112, such that apertures 114 of spring retainer 106 are unable to displace inward ends 113 of toggles 110. As a result of these restrictions, spring retainer 106 is unable to be displaced within piston stop 102 in the direction of stop ring 108, thereby maintaining the compressive load in spring 104. Referring now to FIGS. 1, 1A, 3, 5, 7, and 13, an embodiment of extension assembly 120 will be described. Extension assembly 120 includes an arm drive ring 122, a plurality of arm drive sleeves 124, and a plurality of nozzles 76. When piston 86 is thrust upstream, the motion and force applied to piston 86 is, in turn, transferred to arm drive ring 122. Arm drive ring 122 is circumferentially disposed around piston 86 which is circumferentially disposed around mandrel 82 and within main body 52. As piston 86 thrusts arm drive ring 122 upstream towards drillstring connection 56, arm drive sleeves 124 surrounding radial extensions 126 of drive ring 122 engage distal ends of arm assemblies 66. As arm assemblies 66 are engaged by drive sleeves 124, they are thrust upstream and radially extended along grooves 72 of axial recesses 64. Furthermore, as piston 86 and arm drive ring 122 thrust arm assemblies 66 upstream, radial extensions 98 of spring drive ring 96 compress spring 92 surrounding mandrel 82. Once the thrusting force is removed from piston 86 and arm assemblies 66, spring drive ring 96 will act under the compressed load of spring 92 and retract arm assemblies 66. Referring now to FIGS. 1, 1A, and 3-5, the operation of drilling assembly 50 will now be described. While in the retracted position (shown), drilling fluids flow through drilling assembly 50 from the drillstring through bore 74 and bore 78 of mandrel 82. A seal 128 located between spring retainer 90 and main body 52 prevents fluids from bypassing bore 78 of mandrel 82 and escaping through axial recesses 64. After flowing through bore 78, drilling fluids encounter nozzle 84 where they are accelerated and continue flowing through respective bores 130, 132, 134, and 136 of flow tube 100, piston stop 102, spring retainer 106, and stop ring 108. After exiting bore 136 of stop ring 108, the drilling fluids flow to a plenum 138 within cutting head 54, where they communicate with and flow through nozzles 62 adjacent to cutting structure 58. Because of various sealing mechanisms, drilling fluid is not able to bypass fluid plenum 138 and nozzles 62 when drilling assembly 50 is in its retracted position. Particularly, a seal in groove 140 between mandrel 82 and piston stop 102 prevents fluid from escaping into a chamber 142 prematurely. As chamber 142 is in communication with the annulus through nozzles 76, arm drive ring 122, and a plurality of ports 144, seal in groove 140 prevents loss of drilling fluid pressure when drilling assembly 50 is retracted. Next, upset portion 146 of piston stop 102 forms a seal with inner diameter of piston 86 so that a chamber 148 formed between piston 86 and piston stop 102 cannot communicate with chamber 142. Additionally, a hydraulic seal in groove 147 isolates plenum 138 inside cutting head 54 from a chamber 149 in communication with chamber 148. Furthermore, seal grooves 152 and 153 containing wipers and seals (not shown), prevent drilling fluid from escaping between piston 86 and main body 52. Finally, cutting head 54 is shown attached to main body 52 by means of an oilfield rotary threaded connection 150 approximately between chambers 148 and 149. Because such rotary connections are generally fluid-tight, substantially no drilling fluids escape drilling assembly 50 other than through nozzles 62 when in the retracted state. While a detachable rotary threaded connection 150 is shown, it should be understood that an integrally formed (e.g. welded, machined, etc.) cutting head 54 may also be employed. However, rotary threaded cutting head 54 has the advantage of being removable should cutting head 54 require replacement. Furthermore, because a reduced-height connection is used between cutting head 54 and the rest of drilling assembly 50, cutting head 54 is substantially unitary with expandable cutters 68 and stabilizers 70 such that an axial length therebetween is minimized. A reduced axial length (e.g. between 1-5 times the cutting diameter of cutting head 54) between the trailing edge of cutting head 54 and the leading edge of retracted arm assemblies 66 may be useful in reducing side loads experienced by cutters 68 during operation. Having cutting structures of cutter body 54 proximate and disposed upon the same tool as expandable cutters 68 allows cutting geometry 58 of cutting head 54 to be optimized (if desired) to correspond with the arrangement of cutter elements 68 on arm assemblies 66 to maximize cutting efficiency and durability while reducing vibrations within drilling assembly 50. Referring now to FIGS. 11, 12, 15, and 16, drilling assembly 50 is shown in its fully extended state. When the drilling operator desires to extend arm assemblies 66, the pressure of drilling fluids flowing through the drillstring is increased to a point above a preselected activation value. The geometry of nozzle 84 within flow tube 100 and the spring constant of spring 104 within piston stop 102 are desirably selected to allow for displacement of flow tube 100 within piston stop 102 at the selected activation value. Once reached, fluid flowing across nozzle 84 at the activation pressure creates a resultant force large enough to displace flow tube 100 within mandrel 82 and piston stop 102 against spring 104. Concealed apertures 160 within distal end of mandrel 82, in communication with chamber 142 become exposed as flow tube 100 is displaced downstream. With apertures 160 exposed, drilling fluids within bore 78 of mandrel 82 communicate with nozzle 76 through ports 144 and chamber 142. At this point, the characteristic pressure drop of drilling assembly 50 changes to an intermediate profile, detectable at the surface by an operator. Once the intermediate profile is observed, the operator knows the activation of drilling assembly 50 has begun as with apertures 160 exposed, fluid is able to escape from bore 78 to the annulus through nozzles 76. To fully extend arm assemblies 66 of drilling assembly 50, the pressure of drilling fluids may be maintained or increased so that the pressure across piston 86 between seals 152 and 153 is enough to create enough resultant force in piston to overcome the force of spring 92. As piston 86 is thrust upstream by fluid pressure in chamber 142 acting across seals 152 and 153, the distal end of piston 86 pulls away from outward ends 116 of toggles 110. With piston 86 no longer restraining outward ends 113, toggles 110 pivot around pins 112 thereby allowing spring retainer 106 to be displaced within piston stop 102 until it contacts stop ring 108. With spring retainer 106 displaced into stop ring 108, the compressive load within spring 104 is reduced, thereby preventing flow tube 100 from oscillating back and forth within piston stop 102. Nonetheless, as arm assemblies 66 are thrust upstream by piston 86 in conjunction with drive ring 122, grooves 72 within wall of axial recesses 64 cooperate with corresponding grooves 73 to radially expand arm assemblies 66 until stop ring 99 is encountered as shown in FIG. 11. Referring specifically to FIG. 11, the drilling assembly 50 is shown in the fully expanded state. As can be seen in FIG. 11, with arms filly extended, the distal end of piston 86 is completely clear of portion 146 of piston stop 102. In this position, chambers 142, 148, and 149 are all in fluid communication with each other such that pressurized drilling fluids from bore 78 can communicate with them through apertures 160. Therefore, with arm assemblies 66 fully extended, an indication nozzle 77 (visible in FIG. 3) in communication with chamber 149 is activated such that drilling fluids flowing through bore 78 may escape therethrough. Therefore, when fully activated, drilling assembly 50 will exhibit yet another characteristic pressure drop, one associated with the fully-expanded state. An operator at the surface will be able to observe the change in the pressure drop profile and will know that the drilling assembly 50 is ready to be operated in the extended state. Of particular note, with spring retainer 106 thrust into stop ring 108, the amount of pressure required to maintain flow switch 80 in the fully open position is reduced as the amount of force required to overcome spring 104 is reduced. Therefore, when fully extended, the amount of pressure required to keep flow tube 100 compressed against spring 104 in order to expose apertures 160 is likewise reduced but, as a general rule, the higher pressures are typically maintained. As such, the pressure of drilling fluids necessary to keep arm assemblies 66 extended only needs to be sufficient to overcome the force of compressed spring 92. When retraction of arm assemblies 66 is desired, the pressure of drilling fluids is reduced to a reset level (or cut-off completely) so that spring 92 retracts arm assemblies 66 through spring drive ring 96. The retraction of arm assemblies 66 thrusts piston 86 downstream such that it re-engages upset portion 146 of piston stop 102 and outward ends 116 of toggles 110. As such, spring retainer 106 is driven back to it's original position and spring 104 likewise re-energized to thrust flow tube 100 upstream to cover apertures 160. With arm assemblies 66 retracted, flow is again cut off to nozzles 76 and 77. Once retracted, the operator monitoring the pressure drop at the surface will be aware of the complete retraction of drilling assembly 50 when it exhibits the characteristic pressure drop associated with the retracted profile once again. If any debris or other matter is clogged within axial recesses 64, preventing the complete retraction of arm assemblies 66, the surface operator will be notified when the retracted pressure drop profile is not observed. In such a case the surface operator may attempt to cycle the drilling assembly 50 in an attempt to clear the obstruction. Once reset, the drilling assembly may be re-extended in the same manner as described above. Referring now to FIGS. 17 and 18, an alternative arrangement for an arm assembly 180 is shown. Alternative arm assembly 180 includes an arm 182 having a cutting portion 184 and a stabilizer portion 186. As such, arm 182 translates from a retracted (FIG. 17) position to an extended (FIG. 18) position along a plurality of grooves 188 within a wall of an axial recess 190 of a drilling assembly. In some circumstances, it is desirable for the cutting portion 184 of an arm assembly 180 to engage the borehole before stabilizer portion 186. Particularly, it has been observed that there is some difficulty in beginning a cut when stabilizer portion 186 and cutting portion 184 engage the formation simultaneously. Therefore, arm assembly 180 advantageously allows cutting portion 184 to engage the formation first by employing a radial configuration for grooves 188. Particularly, grooves 188 are constructed as concentric sections of circles having a common center 192 and a maximum radius 194. As such, when retracted within recess 190, arm 182 is positioned such that cutting portion 184 is extended slightly more outward than stabilizer portion 186. However, once extended, both cutting portion 184 and stabilizer portion 186 of arm 182 are at the same radial height. Referring now to FIGS. 19 and 20, a second alternative arrangement for an arm assembly 200 is shown. Alternative arm assembly 200 includes two separate arms, a cutter arm 202 and a stabilizer arm 204, each extendable radially along its own set of linear grooves 206, and 208. As may be appreciated, the extension of cutter arm 202 ahead of stabilizer arm 204 is accomplished by having a steeper slope for stabilizer arm extension grooves 206 than cutter arm grooves 208. In addition, stabilizer arm 204 is installed in the arm pocket such that it is initially inboard of cutter arm 202. However, once extended, both cutter arm 202 and stabilizer arm 204 are at the same radial height. Therefore, cutter arm 202 will engage the formation before stabilizer arm 204. Referring now to FIGS. 21 and 22 together, an alternative drilling assembly 350 is shown. Drilling assembly 350 is depicted in FIG. 21 in a retracted (collapsed) state and is depicted in FIG. 22 in an extended state. As such, drilling assembly 350 includes a main body 352, a cutting head (i.e., a drill bit) 354, and a drillstring connection 356. While a PDC bit is disclosed for cutting head 354, it should be understood that any type or configuration of cutting head or drill bit may be used including, but not limited to, roller cone bits and disc-type bits. As described above, while drillstring connection 356 is depicted as a rotary threaded connection, one of ordinary skill in the art will appreciate that any method of connection between drilling assembly 350 and the remainder of the drillstring (not shown) may be used. For the purposes of this disclosure, drillstring 356 will be considered as the “top” of drilling assembly 350. Furthermore, drilling assembly 350 includes a plurality of axial recesses 364 into which arm assemblies 366 are positioned. As described above, arm assemblies 366 are configured to extend from a retracted (FIG. 21) position to an extended position (FIG. 22) when cutting elements 368 are to be engaged with the formation. Further, while arm assemblies 366 are depicted as having only cutting structure, it should be understood that stabilizers may be positioned upon arm assemblies 366 as well. As described above in reference to drilling assembly 50, arm assemblies 366 travel from their retracted position to their extended position along a plurality of grooves 372 within the wall of axial recesses 364. Corresponding grooves (not visible) along the outer profile of arm assemblies 366 engage grooves 372 and guide arm assemblies 366 as they traverse in and out of axial recesses 364. Referring now to FIG. 23, drilling assembly 350 is shown in further detail. As shown, main body 352 is divided into two threadably connected sections, an upper section 352A and a lower section 352B to ease in the assembly, disassembly, and maintenance of components of drilling assembly 350. While shown divided, one of ordinary skill in the art would understand that a single one-piece member may be constructed for main body 352 without departing from the scope of the claimed subject matter. Furthermore, drilling assembly 350 is actuated from the retracted position (shown) to the extended position by action of a drive piston 386. A flow switch 380 is configured to selectively allow pressure to be applied to drive piston 386. Drive piston 386 is configured to convert pressure from drilling mud in a bore 374 of drilling assembly 350 into force to extend arm assemblies 366 from axial recesses 364. Flow switch 380 further includes a flow mandrel 382 and a selector piston 400. Selector piston 400 is biased upstream by a selector spring 404. Drive piston 386 abuts a drive plate 422, arm assembly 366, and a return block 396. A biasing member 392 acts between a shoulder of main body section 352A and return block 396. Biasing member 392 and selector spring 404 are shown as coil springs, but may be any type of biasing member known to one of ordinary skill in the art including, but not limited to, Bellville washer springs, wave springs, and elastomeric springs. As such, in the retracted position (shown), biasing member 392 urges return block 396 in a downward direction, thereby urging arm assemblies 366 downward. Grooves 372 of axial recesses 364 interact with corresponding grooves (not visible) of arm assembles 366 such that as they are downwardly displaced, arm assemblies 366 radially retract within axial recesses 364. Furthermore, as arm assemblies 366 are retracted, drive plate 422 and drive piston 386 are downwardly displaced. Furthermore, as shown in the retracted position, selector spring 404 thrusts selector piston 400 in an upward direction such that a sealing engagement is made between selector piston 400 and main body section 352B and between selector piston 400 and distal end of flow mandrel 382. In the retracted position shown in FIG. 23, pressurized drilling fluids enter drilling assembly 350 through bore 374 at threaded connection 356 of main body section 352A, travel through flow mandrel 382, through a bore 338 of selector piston 400. Once fluids pass through selector piston bore 338, they flow through distal end of main body section 352B and to drill bit (not shown) below. In this configuration, drilling assembly 350 exhibits a characteristic pressure drop profile corresponding to the un-activated state. A seal 460 prevents fluid from escaping between flow mandrel 382 and selector piston 400. Similarly, seals 462 and 463 prevent fluids from escaping between selector piston 400 and an inner bore of main body section 352B, and seals 464 and 466 isolate drive piston 386 from flow mandrel 382 and main body section 352A, respectively. One of ordinary skill in the art would appreciate that alternative sealing arrangements, geometries, and systems may be used without departing from the claimed subject matter. To extend arm assemblies 366, pressure in bore 374 is increased until an activation value is achieved. Once the activation pressure is reached, the force upon a pressure area 384 of selector piston 400 is sufficient to overcome selector spring 404. As pressure in bore 374 exceeds the activation value, selector piston 400 is thrust downward until seal 460 between selector piston 400 and flow mandrel 3 82 is exposed. Furthermore, as selector piston 400 is downwardly displaced, disengaging seal 460, a secondary pressure area 385 of selector piston 400 is exposed to fluids from bore 374. As a result, the amount pressure in bore 374 required to maintain selector piston 400 in the open position will be less than the amount of fluid pressure required to open selector piston 400 from the closed (shown) position (i.e., the activation pressure). As should be appreciated by those of ordinary skill, the stiffness of selector spring 404 may be selected, the piston area modified, or both to allow opening of selector piston 400 at a desired fluid pressure. With selector piston 400 in the open position, drilling fluids from bore 374 are able to communicate with nozzles 376 and act upon drive piston 386. With drilling fluids in communicat ion with, and exitii ng through nozzles 376, drilling assembly 350 exhibits a characteristic pressure drop profile corresponding to the activated state. Upon noticing the change in pressure drop profile from retracted state to activated state, a drilling operator at the surface is able to determine that selector piston 400 has been activated and that arm assemblies 366 are capable of being extended. Once activated, drilling fluids are able to act upon a pressure area 387 of drive piston 386. As drilling fluid pressure is increased, drive piston 386 displaces drive plate 422, arm assembly 366, and return block 396 against biasing member 392. As such, biasing member 392 may be sized to require a specified amount of force to be applied to arm assemblies 366 by drive piston 386 through grooves 372 before they will extend. Furthermore, the thickness of return block 396 mauy be sized to limit the maximum radial distance arm assemblies 366 may extend. In one embodiment, pressure area 387 of drive piston 386 and biasing member 392 are constructed such that the fluid pressure required to extend arm assemblies 366 is lower than the fluid pressure required to open selector piston 400. Alternatively, drive piston 386 and biasing member 392 may be constructed such that the amount of fluid pressure required to extend arm assemblies 366 is higher than the fluid pressure required to open selector piston 400. Similarly, pressure areas 384 and 385 and selector spring 404 may be selectively constructed to modify the activation pressure of drilling assembly 350. When retraction of arm assemblies 366 is desired, fluid pressure through bore 374 may be reduced such that biasing member 392 may thrust return block 396, arm assembly 366 and drive plate 422 against drive piston 386. If the retraction of arm assemblies 366 is to only be temporary (e.g., when passing through a restriction in the wellbore), the pressure may reduced enough to retract arm assemblies 366, but kept high enough to keep selector piston 400 in the open position. If the retraction is to be for a longer amount of time, the pressure may be dropped below a reset value, where selector piston 400 is returned to a closed position (shown). Referring now to FIGS. 24A-C, the activation of drilling assembly 350 may be further observed. In FIG. 24A, drilling assembly 350 is shown in a retracted and un-activated state, where arm assemblies 366 are retracted within axial recesses 364 and selector piston 400 is in the closed position. In this configuration, pressurized fluids enter bore 374 at drillstring connection 356 and pass through flow mandrel 382, closed selector piston 400, and cutting head 354. In this configuration, drilling assembly 350 exhibits a characteristic pressure drop profile associated with an un-activated state. In this state, drilling assembly 350 may be used for drilling operations without extending arm assemblies 366 as long as the pressure in bore 374 is kept below the activation pressure. Referring now to FIG. 24B, the pressure in bore 374 has reached the activation value such that selector piston 400 is now in the open position and fluids flow from flow mandrel 382, through nozzles 376 and through cutting head 354. In this configuration, drilling assembly 350 is in the activated state, but arm assemblies 366 are not extended. Furthermore, as nozzles 376 are now in communication with fluids in bore 374, drilling assembly 350 exhibits a characteristic pressure drop profile associated with an activated state. In the configuration shown in FIG. 24B, a drilling operator may either increase the pressure of fluids in bore 374 to extend arm assemblies 366, or may reduce the pressure below the reset value to close selector piston 400. Referring now to FIG. 24C, the pressure to bore 374 is increased over the activation value to extend arm assemblies 366. As with FIG. 24B described above, high-pressure fluid enters bore 374 through drillstring connection 356, passes through flow mandrel 382, and flows out through nozzles 376 and cutting head 354 as it bypasses and flows through selector piston 400. Furthermore, the increased pressure acts upon drive piston 386 and extends arm assemblies 366. With arm assemblies 366 extended, cutting elements 368 are able to engage and underream the formation. Alternatively, arm assemblies 366 may include stabilizer pads (not shown) in addition or in place of cutting elements 368, as required by the particular drilling operation. Alternatively still, a third characteristic pressure drop profile corresponding to the fully extended state of arm assemblies 366 may be included within the design of drilling assembly. Such a design would include additional nozzles in communication with bore 374 upon full extension of arm assemblies 366. When retraction is desired, pressure in bore 374 is reduced and biasing member 392 retracts arm assemblies 366 though return block 396. With arm assemblies 366 retracted, selector piston 400 may remain in the open position (with drilling assembly 350 exhibiting the activated pressure drop) until pressure in bore 374 falls below a reset value. Once drilling assembly 350 is reset with selector piston 400 in the closed position, the un-activated pressure drop is observed and drilling assembly 350 may remain in the borehole without concern for re-activation unless pressure in bore 374 exceeds the activation value again. In one exemplary embodiment, drilling assembly 350 may expand from 5 5/8″ to 7″ with arm assemblies 366 extended. Thus, cutting head 354 may be, at a minimum, a 6″ gauge drill bit. As such, drilling assembly 350 may be constructed such that cutting elements 368 of arm assemblies 366 are within 30 inches (ie., within 5 times the diameter) of cutting head 354. Furthermore, drilling assembly 350 may be constructed to activate in response to an increase in pressure of 350 psi and fully open in response to an additional increase of 115 psi. However, it should be understood by one of ordinary skill in the art that other gauge sizes and pressure differentials may be used without departing from the scope of the claims appended hereto. Embodiments disclosed herein may have various advantages over the prior art. Particularly, the drilling assemblies disclosed herein include bits, an underreamers, and/or stabilizers within close axial proximity to one another. Advantageously, having an adjustable stabilizer proximate (e.g. axially spaced within 1-5 times the diameter of the pilot bit) to an underreamer may prevent the underreamer from taking heavy side loads and assuming the role of a fulcrum in a directionally drilled wellbore. Having an adjustable stabilizer adjacent to the cutting structure of an underreamer may prevent premature wear and damage to the cutting structure as a result of such side loading. Furthermore, having the pilot bit assembly proximate to an underreamer may further minimize the fulcrum effect, thereby maximizing the life of the cutting structures of both the pilot bit and the underreamer. By making the pilot bit integral with the underreamer mechanism, the axial length therebetween may be minimized. Furthermore, the optional flex member located upstream of the stabilizer/underreamer mechanism may enable larger build rates in certain directional drilling applications. The use of such an flex member is described by U.S. patent application Ser. No. 11/334,707 entitled “Flexible Directional Drilling Apparatus and Method” filed on Jan. 18, 2006 by inventors Lance Underwood and Charles Dewey, hereby incorporated by reference in its entirety. Depending on the geometry and type of equipment upstream of a flex member, the combination of the pilot bit, underreamer, and/or stabilizer may be treated together as a fulcrum in a directional drilling system, rather than each component as a single node in a flexible string. As such, additional expandable stabilizers, including those of the type described in U.S. Pat. No. 6,732,817, may be located upstream of the drilling assembly to implicate a desired build angle in the trajectory of the drilling assembly. Furthermore, the drilling assemblies disclosed herein have the aforementioned benefit of distinct changes in the pressure drop profile to indicate the status of tool activation and/or the arm assemblies. Particularly, using the drilling assembly disclosed herein, a driller will be able to know, with some degree of accuracy, when the arms may be retracted, when they are fully extended, and when they are in transition from retracted to extended. As such, the operator will no longer have to guess or estimate what state the underreamer or stabilizer is in. Finally, as mentioned above, the drilling assembly disclosed herein employs actuation mechanisms that not only indicate the status of actuation, but are also capable of being completely reset to their pre-activation states. Particularly, as outlined above, former actuation mechanisms could not be deactivated once activated, thereby reducing the flexibility of the bottom hole apparatus following activation. In contrast, using the actuation mechanisms disclosed herein, downhole tools may return to their original state when their activated state is no longer needed. Therefore, if, after drilling an underreamed hole for a particular distance, a non-underreamed borehole is desired, the drilling assemblies disclosed herein may drill such a borehole without the need to return to the surface for resetting. While a hydraulic actuation mechanism and the benefits thereof have been described in detail, it should be understood by one of ordinary skill in the art that such a mechanism is not a required component of the drilling system disclosed herein. Alternatively, for certain circumstances, a simplified shear member activation mechanism may be used instead. While preferred embodiments of this disclosure have been shown and described, modifications thereof may be made by one skilled in the art without departing from the spirit or teaching of this disclosure. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.
|
E
|
E21
|
E21B
|
10
|
32
|
|||
11776750
|
US20080102594A1-20080501
|
METHOD FOR FORMING SEMICONDUCTOR MEMORY CAPACITOR WITHOUT CELL-TO-CELL BRIDGES
|
ACCEPTED
|
20080422
|
20080501
|
[]
|
H01L21306
|
["H01L21306"]
|
7498267
|
20070712
|
20090303
|
438
|
706000
|
85142.0
|
NHU
|
DAVID
|
[{"inventor_name_last": "KIM", "inventor_name_first": "Gyu Hyun", "inventor_city": "Kyoungki-do", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "CHOI", "inventor_name_first": "Yong Soo", "inventor_city": "Kyoungki-do", "inventor_state": "", "inventor_country": "KR"}]
|
A capacitor is formed by forming a mold insulating layer with a plurality of storage node holes over a semiconductor substrate. A metal storage node is formed on the surface of each of the storage node holes in the mold insulating layer. The mold insulating layer is removed by performing the following steps: loading the semiconductor substrate with the storage node in the chamber for in-situ cleaning, rinsing, and drying processes; removing the mold insulating layer by an etchant in the chamber; then rinsing the semiconductor substrate by introducing deionized water into the chamber while discharging the etchant out of the chamber; finally rinsing the rinsed semiconductor substrate with a mixed solution of the deionized water and organic solvent; drying the finally rinsed semiconductor substrate by IPA vapor in the chamber while discharging the mixed solution of the deionized water and organic solvent out of the chamber.
|
1. A method for forming a capacitor comprising steps of: forming a mold insulating layer with a plurality of storage node holes over a semiconductor substrate; forming a storage node on the surface of each of the storage node holes in the mold insulating layer; and removing the mold insulating layer comprising steps of: loading the semiconductor substrate with the storage node in the chamber in which a cleaning process, rinse process, and drying process are performed in an in-situ manner; removing the mold insulating layer by introducing an etchant into the chamber; rinsing the semiconductor substrate with the mold insulating layer being removed by introducing deionized water into the chamber while discharging the etchant out of the chamber; finally rinsing the rinsed semiconductor substrate with a mixed solution of deionized water and an organic solvent; drying the finally rinsed semiconductor substrate by introducing an iso-propylene alcohol (IPA) vapor into the chamber while discharging the mixed solution of deionized water and organic solvent out of the chamber; and unloading the dried semiconductor substrate. 2. The method according to claim 1, wherein the storage node made of metal. 3. The method according to claim 1, wherein the etchant for removing the mold insulating layer is used with a BOE solution or a diluted HF solution. 4. The method according to claim 3, wherein the diluted HF solution has HF:H2O ratio of 49%:51% with a HF:H2O volume ratio of 1:1˜1:50. 5. The method according to claim 1, wherein the rinsing step of the semiconductor substrate comprises steps of: first rinsing with only the deionized water introduced into the chamber; and second rinsing with the deionized water and O3 by introducing O3 into the chamber. 6. The method according to claim 5, wherein the second rinsing step is performed with O3 maintained at a concentration of 5˜200 ppm. 7. The method according to claim 5, wherein the second rinsing step is performed for 1˜10 minutes. 8. The method according to claim 1, wherein the final rinsing step is performed using a mixed solution of deionized water and any one of IPA, methanol, and ethanol as the organic solvent. 9. The method according to claim 8, wherein the final rinsing step is performed using the mixed solution of the deionized water and the IPA. 10. The method according to claim 9, wherein the IPA is contained at a volume ratio of 1˜99%. 11. The method according to claim 9, wherein the final rinsing step is performed by controlling the temperature of the mixed solution of deionized water and the IPA at 23˜70° C. 12. The method according to claim 1, wherein the drying step of the semiconductor substrate is performed by introducing into the chamber a hot N2 gas as a carrier gas for the IPA vapor. 13. The method according to claim 12, wherein the hot N2 gas has a temperature of 50˜200° C. 14. The method according to claim 12, wherein the IPA has vapor contents of 20˜90% in the mixed gas of the IPA and hot N2 gas. 15. The method according to claim 1, wherein the chamber is used with a dHF & Rinsing Dryer (FRD) type dryer that is capable of performing the cleaning process, rinse process, and drying process in an in-situ manner. 16. The method according to claim 15, wherein the FRD type dryer comprises: a chamber in which all or any combination of the cleaning process, rinse process, and drying process are performed; a cover covering the chamber; a deionized water supply bath, an etchant supply bath, an O3 generator, and an organic solvent bath, all of which are connected to the chamber for providing the deionized water, etchant, O3 and organic solvent, respectively; and an IPA vapor generator connected to the chamber for providing the IPA vapor. 17. The method according to claim 16, wherein the IPA vapor generator is connected to an upper portion of the cover. 18. The method according to claim 16, wherein the FRD type dryer further comprises a hot N2 gas supplier connected to the IPA vapor generator for providing the hot N2 gas. 19. The method according to claim 16, wherein the FRD type dryer further comprises: a supply port connected to the lower side portion of the chamber for introducing the deionized water, etchant, O3 and organic solvent into the chamber; and a drain connected to the bottom portion of the chamber for discharging the solutions introduced into the chamber out of the chamber.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to a method for forming a capacitor, and more particularly to a method for forming a capacitor capable of preventing the generation of cell-to-cell bridges upon the formation of cylindrical metal storage nodes. A capacitor has a structure in which a dielectric layer is interposed between a storage node and a plate node. The capacitance is proportional to the surface area of the node and the dielectric constant of the dielectric layer and inversely proportional to the distance between the nodes, i.e., the thickness of the dielectric layer. Therefore, in order to achieve high capacitance, it is necessary to use a dielectric layer having a high dielectric constant and/or enlarge the surface area of the node and/or reduce the distance between the nodes. A concave-type silicon-insulator-silicon (SIS) capacitor which employs poly-silicon as node materials has been conventionally used. However, such a concave-type SIS capacitor has difficulties in decreasing the surface area and increasing the height of the capacitor due to reduction in the cell size, which limits the SIS capacitor's ability to secure the capacitance. Further, although research concerning dielectric layer having a larger dielectric constant has been actively conducted in a variety of ways with regard to terms of structure and method, leakage current increases the difficulty of using a dielectric layer having a larger dielectric constant. Therefore, a capacitor has been recently developed which employs metals of higher work function as the node materials. Moreover, the capacitor structure is changed from concave to cylindrical, since the smaller size of the storage node limits the extent to which the height of the capacitor may be increased. On the other hand, when forming the cylindrical metal-insulator-metal (MIM) capacitor using the metal node, a mold insulating layer of oxide layer must be removed after forming the cylindrical metal storage node. For these purposes, a cleaning process using a Buffered Oxide Etchant (BOE) was conventionally implemented. Hereinafter, the conventional cleaning process which removes the mold insulating layer upon forming the cylindrical MIM capacitor will be briefly described. First, in order to remove the mold insulating layer, the cleaning process is performed by immersing a semiconductor substrate with the metal storage node in the BOE bath containing BOE solution layer. The resulting substrate with the mold insulating layer being removed is moved into a rinse bath, where it is rinsed with deionized water in order to remove BOE chemical residues. Subsequently, the rinsed resulting substrate is moved into another rinse bath, where it is finally rinsed with the deionized water in order to remove any particles. Then, the final rinsed substrate is moved into a dryer, where it is dried. The drying process is performed using an isopropyl alcohol (IPA) vapor dryer, a Marangoni dryer, or an IPA vapor spray dryer. In the prior art described above, however, the substrate is exposed to the atmosphere each time the substrate is moved to different bathes (i.e., chambers) for performing the cleaning process, rinse process, resulting rinse process, and drying process, and these exposures lead to certain portions of the substrate being dried out. As a result, watermarks are generated between neighboring cylindrical metal storage nodes. Such watermarks may be generated even when the water in the substrate is not completely substituted into the IPA during the drying process. FIG. 1 shows examples of such watermarks 120 generated upon the formation of the cylindrical metal storage node. It can be noted from FIG. 1 that the watermarks 120 are generated between the neighboring cylindrical metal storage nodes 110 . However, if watermarks are generated between the cylindrical metal storage nodes, the watermarks may apply surface tension to the side walls of the neighboring cylindrical metal storage nodes such that cell-to-cell leaning is caused, thereby creating cell-to-cell bridges as shown in FIG. 2 . It is impossible to repair such cell-to-cell bridges, which reduce the manufacturing yield of the semiconductor device.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Embodiments of the present invention are directed to a method for forming a capacitor which can prevent the formation of watermarks between metal storage nodes upon the formation of cylindrical metal storage nodes. Further, embodiments of the present invention are directed to a method for forming a capacitor which can prevent the formation of cell-to-cell bridges by preventing formation of watermarks between the metal storage nodes. Also, embodiments of the present invention are directed to a method for forming a capacitor, which can prevent reduction in manufacturing yield by preventing the formation of cell-to-cell bridges. In one embodiment, a method for forming a capacitor comprises steps of forming a mold insulating layer with a plurality of storage node holes over a semiconductor substrate; forming a storage node on the surface of each of the plurality of storage node holes in the mold insulating layer; and removing the mold insulating layer, wherein the removal step comprises steps of loading the semiconductor substrate with the storage node in the chamber where a cleaning process, rinse process and drying process are performed in an in-situ manner; removing the mold insulating layer by introducing an etchant into the chamber; rinsing the semiconductor substrate with the mold insulating layer being removed by introducing a deionized water into the chamber while discharging the etchant out of the chamber; finally rinsing the rinsed semiconductor substrate with a mixed solution of the deionized water and an organic solvent; drying the finally rinsed semiconductor substrate by introducing an IPA vapor into the chamber while discharging the mixed solution of the deionized water and the organic solvent out of the chamber; and unloading the dried semiconductor substrate. The storage node made of metal. The etchant for removing the mold insulating layer is used with a BOE solution or a diluted HF solution and the diluted HF solution has a ratio of 49% HF:H 2 O and a volume ratio of 1:1˜1:50. The rinsing step of the semiconductor substrate comprises steps of first rinsing with only the deionized water introduced into the chamber; and second, rinsing with the deionized water and O 3 by introducing O 3 into the chamber. The second rinsing step is performed with O 3 maintained at a concentration of 5˜200 ppm for 1˜10 minutes. The final rinsing step is performed using a mixed solution of any one of an IPA, a methanol or an ethanol as the organic solvent and the deionized water. Preferably, the IPA is contained at a volume ratio of 1˜99%, and the final rinsing step is performed by controlling the temperature of the mixed solution of the deionized water and the IPA at 23˜70° C. The drying step of the semiconductor substrate is performed by introducing a hot N 2 gas as a carrier gas for the IPA vapor into the chamber, and the hot N 2 gas has a temperature of 50˜200° C. The IPA has vapor contents of 20˜90% in the mixed gas of the IPA and the hot N 2 gas. The chamber is used with a FRD (dHF & Rinsing Dryer) type dryer in which the cleaning process, rinse process and drying process are performed in an in-situ manner. The FRD type dryer comprises the chamber in which the cleaning process, rinse process and drying process are performed; a cover covering the chamber; a deionized water supply bath, an etchant supply bath, an O 3 generator and an organic solvent bath connected to the chamber for providing the deionized water, the etchant, the O 3 and the organic solvent, respectively; and an IPA vapor generator connected to the chamber for providing the IPA vapor. The IPA vapor generator is connected to an upper portion of the cover. The FRD type dryer further comprises a hot N 2 gas supplier connected to the IPA vapor generator for providing the hot N 2 gas. The FRD type dryer further comprises a supply port connected to the lower side portion of the chamber for introducing the deionized water, etchant, O 3 and organic solvent into the chamber; and a drain connected to the bottom portion of the chamber for discharging the solutions introduced into the chamber out of the chamber
|
CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to Korean patent application number 10-2006-0106909 filed on Oct. 31, 2006, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION The present invention relates to a method for forming a capacitor, and more particularly to a method for forming a capacitor capable of preventing the generation of cell-to-cell bridges upon the formation of cylindrical metal storage nodes. A capacitor has a structure in which a dielectric layer is interposed between a storage node and a plate node. The capacitance is proportional to the surface area of the node and the dielectric constant of the dielectric layer and inversely proportional to the distance between the nodes, i.e., the thickness of the dielectric layer. Therefore, in order to achieve high capacitance, it is necessary to use a dielectric layer having a high dielectric constant and/or enlarge the surface area of the node and/or reduce the distance between the nodes. A concave-type silicon-insulator-silicon (SIS) capacitor which employs poly-silicon as node materials has been conventionally used. However, such a concave-type SIS capacitor has difficulties in decreasing the surface area and increasing the height of the capacitor due to reduction in the cell size, which limits the SIS capacitor's ability to secure the capacitance. Further, although research concerning dielectric layer having a larger dielectric constant has been actively conducted in a variety of ways with regard to terms of structure and method, leakage current increases the difficulty of using a dielectric layer having a larger dielectric constant. Therefore, a capacitor has been recently developed which employs metals of higher work function as the node materials. Moreover, the capacitor structure is changed from concave to cylindrical, since the smaller size of the storage node limits the extent to which the height of the capacitor may be increased. On the other hand, when forming the cylindrical metal-insulator-metal (MIM) capacitor using the metal node, a mold insulating layer of oxide layer must be removed after forming the cylindrical metal storage node. For these purposes, a cleaning process using a Buffered Oxide Etchant (BOE) was conventionally implemented. Hereinafter, the conventional cleaning process which removes the mold insulating layer upon forming the cylindrical MIM capacitor will be briefly described. First, in order to remove the mold insulating layer, the cleaning process is performed by immersing a semiconductor substrate with the metal storage node in the BOE bath containing BOE solution layer. The resulting substrate with the mold insulating layer being removed is moved into a rinse bath, where it is rinsed with deionized water in order to remove BOE chemical residues. Subsequently, the rinsed resulting substrate is moved into another rinse bath, where it is finally rinsed with the deionized water in order to remove any particles. Then, the final rinsed substrate is moved into a dryer, where it is dried. The drying process is performed using an isopropyl alcohol (IPA) vapor dryer, a Marangoni dryer, or an IPA vapor spray dryer. In the prior art described above, however, the substrate is exposed to the atmosphere each time the substrate is moved to different bathes (i.e., chambers) for performing the cleaning process, rinse process, resulting rinse process, and drying process, and these exposures lead to certain portions of the substrate being dried out. As a result, watermarks are generated between neighboring cylindrical metal storage nodes. Such watermarks may be generated even when the water in the substrate is not completely substituted into the IPA during the drying process. FIG. 1 shows examples of such watermarks 120 generated upon the formation of the cylindrical metal storage node. It can be noted from FIG. 1 that the watermarks 120 are generated between the neighboring cylindrical metal storage nodes 110. However, if watermarks are generated between the cylindrical metal storage nodes, the watermarks may apply surface tension to the side walls of the neighboring cylindrical metal storage nodes such that cell-to-cell leaning is caused, thereby creating cell-to-cell bridges as shown in FIG. 2. It is impossible to repair such cell-to-cell bridges, which reduce the manufacturing yield of the semiconductor device. SUMMARY OF THE INVENTION Embodiments of the present invention are directed to a method for forming a capacitor which can prevent the formation of watermarks between metal storage nodes upon the formation of cylindrical metal storage nodes. Further, embodiments of the present invention are directed to a method for forming a capacitor which can prevent the formation of cell-to-cell bridges by preventing formation of watermarks between the metal storage nodes. Also, embodiments of the present invention are directed to a method for forming a capacitor, which can prevent reduction in manufacturing yield by preventing the formation of cell-to-cell bridges. In one embodiment, a method for forming a capacitor comprises steps of forming a mold insulating layer with a plurality of storage node holes over a semiconductor substrate; forming a storage node on the surface of each of the plurality of storage node holes in the mold insulating layer; and removing the mold insulating layer, wherein the removal step comprises steps of loading the semiconductor substrate with the storage node in the chamber where a cleaning process, rinse process and drying process are performed in an in-situ manner; removing the mold insulating layer by introducing an etchant into the chamber; rinsing the semiconductor substrate with the mold insulating layer being removed by introducing a deionized water into the chamber while discharging the etchant out of the chamber; finally rinsing the rinsed semiconductor substrate with a mixed solution of the deionized water and an organic solvent; drying the finally rinsed semiconductor substrate by introducing an IPA vapor into the chamber while discharging the mixed solution of the deionized water and the organic solvent out of the chamber; and unloading the dried semiconductor substrate. The storage node made of metal. The etchant for removing the mold insulating layer is used with a BOE solution or a diluted HF solution and the diluted HF solution has a ratio of 49% HF:H2O and a volume ratio of 1:1˜1:50. The rinsing step of the semiconductor substrate comprises steps of first rinsing with only the deionized water introduced into the chamber; and second, rinsing with the deionized water and O3 by introducing O3 into the chamber. The second rinsing step is performed with O3 maintained at a concentration of 5˜200 ppm for 1˜10 minutes. The final rinsing step is performed using a mixed solution of any one of an IPA, a methanol or an ethanol as the organic solvent and the deionized water. Preferably, the IPA is contained at a volume ratio of 1˜99%, and the final rinsing step is performed by controlling the temperature of the mixed solution of the deionized water and the IPA at 23˜70° C. The drying step of the semiconductor substrate is performed by introducing a hot N2 gas as a carrier gas for the IPA vapor into the chamber, and the hot N2 gas has a temperature of 50˜200° C. The IPA has vapor contents of 20˜90% in the mixed gas of the IPA and the hot N2 gas. The chamber is used with a FRD (dHF & Rinsing Dryer) type dryer in which the cleaning process, rinse process and drying process are performed in an in-situ manner. The FRD type dryer comprises the chamber in which the cleaning process, rinse process and drying process are performed; a cover covering the chamber; a deionized water supply bath, an etchant supply bath, an O3 generator and an organic solvent bath connected to the chamber for providing the deionized water, the etchant, the O3 and the organic solvent, respectively; and an IPA vapor generator connected to the chamber for providing the IPA vapor. The IPA vapor generator is connected to an upper portion of the cover. The FRD type dryer further comprises a hot N2 gas supplier connected to the IPA vapor generator for providing the hot N2 gas. The FRD type dryer further comprises a supply port connected to the lower side portion of the chamber for introducing the deionized water, etchant, O3 and organic solvent into the chamber; and a drain connected to the bottom portion of the chamber for discharging the solutions introduced into the chamber out of the chamber BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows examples of watermarks generated upon the formation of cylindrical metal storage nodes. FIG. 2 shows examples of cell-to-cell leaning caused by the generation of watermarks upon the formation of prior cylindrical metal storage nodes. FIGS. 3A through 3F are cross-sectional views for showing the process steps of a method for forming a cylindrical MIM capacitor in accordance with another embodiment of the present invention. FIG. 4 is a cross-sectional view for showing a HF rinse dryer (FRD) type dryer. FIGS. 5A through 5G are diagrams illustrating the cleaning process, rinse process and drying process in the method for forming a capacitor in accordance with another embodiment of the present invention. DESCRIPTION OF SPECIFIC EMBODIMENTS A cleaning process, rinse process, and drying process for removing a mold insulating layer according to an embodiment of the present invention are performed in an in-situ manner within the same chamber and do not require the substrate to be moved. In this case, since the substrate is not exposed to the atmosphere at the time of the cleaning process, rinse process, and drying process, it is possible to prevent the residual water in the substrate from drying, thereby preventing watermarks from being formed and cell-to-cell bridges from being generated between the metal storage nodes. Further, in an embodiment of the present invention, the final rinse process preceded by the drying process is performed using a mixed solution of deionized water and an organic solvent rather than solely deionized water. In this case, since surface tension of the residual water in the substrate is reduced by the organic solvent, the subsequent drying process can be performed when the surface tension of the water is minimal. Therefore, all of the water on the substrate can be substituted into the isopropyl alcohol (IPA), whereby the generation of watermarks between the metal storage nodes is prevented and thus cell-to-cell bridges are not created. Therefore, according to an embodiment of the present invention, it is possible to prevent watermarks from being generated between the metal storage nodes by performing in-situ processes and using a mixed solution of the deionized water and organic solvent in the final rinse process. As a result, the present invention makes it possible to prevent cell-to-cell leaning and cell-to-cell bridges from being caused by watermarks, and thus prevents a reduction in the manufacturing yield of the semiconductor device. FIG. 3A through 3F are cross-sectional views illustrating the process steps of a method for manufacturing a cylindrical MIM capacitor according to an embodiment of the present invention. Referring to FIG. 3A, an interlayer insulating layer 302 is deposited over a semiconductor substrate 300, and then a contact hole is formed by etching the interlayer insulating layer 302. A storage node contact plug 304 is formed by filling the contact hole with poly-silicon layer. An etch-stop nitrate layer 306 having a thickness of approximately 800A is formed on the interlayer insulating layer 302 including the storage node contact plug 304. The etch-stop nitrate layer 306 is formed at a temperature of approximately 710° C. using N2 gas, NH3 gas, and DCS (Dichlorosilane; SiH2Cl2) gas as a source gas in a furnace. The etch-stop nitrate layer 306 serves to protect against etch attack by the lower structure of the storage node, i.e., the interlayer insulating layer 302 and the storage node contact plug 304 in a subsequent dip-out process for removing the mold insulating layer. Referring to FIG. 3B, the mold insulating layer 308 serving as a mold for the cylindrical storage node is formed on the etch-stop nitrate layer 306. The mold insulating layer 308 is formed as a laminated layer having a PE-TEOS layer, an O3-TEOS layer, an O3-USG layer, a PSG layer, and a PE-TEOS layer or a laminated layer having a BPSG layer and a PE-TEOS layer. Referring to FIG. 3C, a hard mask layer 310 and a mask pattern 312 defining the storage node formation area are sequentially formed on the mold insulating layer 308. The hard mask layer 310 is typically formed with poly-silicon in order to compensate for difficulties in pattern formation, such as collapses occurring at side surfaces of the pattern, since sufficient selectivity cannot be ensured by solely the mask pattern 312 in the subsequent etch process. Referring to FIG. 3D, exposed portions of the hard mask layer 310 are etched by HBr, Cl2, and O2 gases using the mask pattern 312 as an etch mask, and then the mask pattern is removed. The mold insulating layer 308 is etched using the etched hard mask layer 310 as etch mask and using etch selectivity between the oxide layer and the nitrate layer. The mold insulating layer 308 is etched using C4F6, O2 and CF4 gas. The hard mask layer 310 is removed via the etch process using C2F6 and O2 gas. The portions of the etch-stop nitrate layer 306 exposed by etching the mold insulating layer 308 are removed, whereby storage node holes H are formed to expose the storage node contact plug 304. Referring to FIG. 3E, a TiN layer having a thickness of approximately 300 Å is deposited as a storage node conductive layer on surfaces of the hole H and the mold insulating layer 308. The TiN layer is deposited at a temperature of 580° C. via Chemical Vapor Deposition (CVD) using TiCl4 gas. The TiN layer formed on the mold insulating layer 308 is selectively removed by a plasma-etching process using Cl2 and Ar gas as etching gas, whereby the cylindrical metal storage node 314 contacted with the exposed storage node contact plug 304 is formed on the surfaces of the hole H. The storage node 314 can be formed with a W layer or a Ru layer instead of the TiN layer. Referring to FIG. 3F, the mold insulating layer used as the mold for forming the cylindrical metal storage node 314 is removed using a FRD (HF rinse dryer) type dryer in which the cleaning process, the rinse process and the drying process are performed in an in-situ manner within the same equipment, to finish forming the cylindrical metal storage node 314. Although not shown, the dielectric layer and the metal plate node are sequentially formed on the cylindrical metal storage node 314, thereby forming the cylindrical MIM capacitor. FIG. 4 is a cross-sectional view illustrating the FRD type dryer used in the method for forming the capacitor according to an embodiment of the present invention. The FRD type dryer 400 according to an embodiment of the present invention can allow the cleaning process, the rinse process, and the drying process to be performed in an in-situ manner within the same equipment. As shown in FIG. 4, the FRD type dryer 400 includes a chamber 410 in which the cleaning process, rinse process and drying process are performed, a cover 420 covering the chamber 410, a deionized water supply bath 430 providing the deionized water, etchant, O3 and the organic solvent, respectively, an etchant supply bath 440, an O3 generator 450, and an organic solvent bath 460, and an iso-propylene alcohol (IPA) vapor generator 470 which is connected to the chamber 410 for providing the IPA vapor. The FRD type dryer 400 according to an embodiment of the present invention further includes a hot N2 gas supplier 480 which is connected to the IPA vapor generator 470 for providing a hot N2 gas. The lower side portion of the chamber 410 is connected to a supply port 490 through which deionized water, etchant, O3 and organic solvent are introduced into the chamber 410. The bottom of the chamber 410 is connected to a drain 492 through which the solutions and the gas introduced into the chamber 410 are discharged out of the chamber 410. The IPA vapor generator 470 is connected to an upper portion of the cover 420 by the IPA vapor supply port 494. In order to remove the mold insulating layer 308 using the FRD type dryer 400, the cleaning process for etching the insulating layer using a diluted HF solution within the chamber, the rinse process for rinsing the cleaned substrate, and the drying process for drying the rinsed substrate are all performed in an in-situ manner. Therefore, the substrate is not exposed to the atmosphere during the processes. More specifically, if the semiconductor substrate with the metal storage node is carried into the chamber 410, the etchant, deionized water, O3, organic solvent and IPA vapor containing the hot N2 gas are sequentially introduced into the chamber 410 via the supply port 490 connected to the bottom side portion of the chamber 410, whenever the cleaning process, rinse process and drying process are performed. At this time, the etchant, deionized water, O3, and organic solvent are introduced into the chamber 410 via the supply port 490 in accordance with the on/off status of the valve 496 connected to the supply port 490, and the IPA vapor is introduced into the chamber 410 via the IPA vapor supply port 494 above the chamber 410. Hot N2 gas at a temperature of 80˜200° C. is introduced into the chamber 410 as a carrier gas together with the IPA vapor. Further, whenever each process is finished, the solution used in the prior process is discharged out of the chamber 410 via the drain 492 located at the bottom of the chamber 410. Moreover, new solution necessary for the next process is introduced into the chamber 410 via the supply port 490. Therefore, since the present invention allows the cleaning process, rinse process and drying process for removing the mold insulating layer to be performed in an in-situ manner within the chamber without a need to move the semiconductor substrate, it is possible to prevent watermarks from being formed between the metal storage nodes, thereby preventing the generation of cell-to-cell leaning and cell-to-cell bridges, which are caused by watermarks. Hereinafter, referring to FIGS. 5A through 5G, the cleaning process, rinse process and drying process will be described specifically using the above-mentioned FRD type dryer. Referring to FIG. 5A, the semiconductor substrate 500 with the metal storage node is loaded into the chamber 410 of the FRD type dryer. Referring to FIG. 5B, the etchant 442 is introduced from the etchant supply bath 440 into the chamber 410 via the supply port 490 connected to a lower side portion of the chamber 410 such that the cleaning process for removing the mold insulating layer may be performed. It is preferable to employ the BOE solution or the diluted HF solution as the etchant and to use a diluted HF solution of 49% (HF):51% (H2O) with HF:H2O volume ratio of 1:1˜1:50. Referring to FIG. 5C, the etchant is discharged out of the chamber 410 via the drain 492 located at the bottom of the chamber 410, and deionized water 432 is subsequently introduced from the deionized water supply bath 430 into the chamber 410 via the supply port 490 such that the semiconductor substrate 500 with the mold insulating layer being removed from it is first rinsed. Referring to FIG. 5D, O3 is introduced into the chamber with the deionized water via the supply port 490 connected to the chamber 410 such that the first rinsed semiconductor substrate 500 may be rinsed a second time with the deionized water and O3 solution 452. The deionized water and O3 solution 452 maintains an O3 concentration of 5˜200 ppm. The second rinse process using the deionized water and O3 solution 452 is performed for 1˜10 minutes. Referring to FIG. 5E, the deionized water and O3 solution 452 is discharged out of the chamber 410 via the drain 492, and the deionized water and organic solvent are then introduced into the chamber 410 from the deionized water supply bath 430 and the organic solvent bath 460, respectively, via the supply port 490 such that the second rinsed semiconductor substrate 500 may be finally rinsed with a mixed solution 462 of deionized water and organic solvent. Any one of IPA, methanol, and ethanol can be used as the organic solvent, although IPA is preferred. When IPA is used, the IPA is maintained at a volume ratio of 1˜99% in the mixed solution 462 of deionized water and organic solvent. The mixed solution of deionized water and organic solvent is controlled at a temperature of 23˜70° C. Therefore, the final rinse process is performed using the mixed solution of deionized water and organic solvent, thereby reducing the surface tension of the residual water in the semiconductor substrate. Referring to FIG. 5F, the mixed solution of deionized water and organic solvent is discharged out of the chamber 410 via the drain 492. Referring to FIG. 5G, the IPA vapor is introduced into the chamber 410 from the IPA vapor generator 470 via the IPA vapor supply port 494 so that the final rinsed semiconductor substrate may be dried. At this time, the hot N2 gas at a temperature of 50˜200° C. is released into the IPA vapor generator 470 from the hot N2 gas supplier 480 and acts as a carrier gas for the IPA vapor, whereby the hot N2 gas is introduced into the chamber 410 together with the IPA vapor. At this time, the mixed gas of IPA vapor and hot N2 gas has IPA vapor contents of 20˜90%. Herein, the present invention can allow the residual water remaining in the substrate to be substituted into the IPA, since larger amounts of IPA vapor flow into the chamber 410 one time in a state such that the surface tension of the residual water in the substrate is minimized. Further, the present invention can prevent the watermarks forming between the metal storage nodes, and thus prevent cell-to-cell leaning and cell-to-cell bridges caused by the generation of watermarks, since the cleaning process and subsequent rinse and drying processes for removing the mold insulating layer may be performed in in-situ within the same chamber. As is apparent from the above description, the present invention can allow the cleaning process, rinse process, and drying process for removing the mold insulating layer to be performed in an in-situ manner upon forming the cylindrical storage node, as well as the final rinse process performed with the mixed solution of deionized water and organic solvent such that the subsequent drying process is performed in a state where the surface tension is minimized. Therefore, the present invention prevents the formation of watermarks between the metal storage nodes and thus prevents cell-to-cell leaning and cell-to-cell bridges caused by the generation of watermarks, which results in an improvement in the manufacturing yield of the semiconductor device. Although specific embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and the spirit of the invention as disclosed in the accompanying claims.
|
H
|
H01
|
H01L
|
213
|
06
|
|||
11981065
|
US20090110183A1-20090430
|
Method, system, and apparatus for attenuating dual-tone multiple frequency confirmation tones in a telephone set
|
ACCEPTED
|
20090415
|
20090430
|
[]
|
H04M300
|
["H04M300"]
|
8335308
|
20071031
|
20121218
|
379
|
353000
|
93728.0
|
LYTLE
|
JEFFREY
|
[{"inventor_name_last": "Ray", "inventor_name_first": "Amar Nath", "inventor_city": "Shawnee", "inventor_state": "KS", "inventor_country": "US"}]
|
A method, system, and apparatus for attenuating a dialing confirmation tone includes receiving an enable signal from a tactile user input device, generating at least one dual-tone multiple frequency (DTMF) tone, and communicating the at least one DTMF tone to a telephone line. The method further includes attenuating a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal, and communicating the at least one attenuated dialing confirmation tone to an audio output device.
|
1. A method for attenuating a dialing confirmation tone comprising: receiving an enable signal from a tactile user input device; generating at least one dual-tone multiple frequency (DTMF) tone; communicating the at least one DTMF tone to a telephone line; attenuating a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal; and communicating the at least one attenuated dialing confirmation tone to an audio output device. 2. The method of claim 1, further comprising: receiving a disable signal from the tactile user input device; and providing the at least one DTMF tone to the audio output device as at least one dialing confirmation tone in response to receiving the disable signal. 3. The method of claim 1, wherein receiving the enable signal includes receiving the enable signal from the tactile user input device configured as a key. 4. The method of claim 1, wherein communicating the at least one DTMF tone to a telephone line includes communicating an analog signal over an analog telephone line. 5. The method of claim 1, wherein communicating the at least one attenuated dialing confirmation tone to an audio output device includes communicating the at least one attenuated dialing confirmation tone to an audio output device of a telephone set. 6. The method of claim 1, wherein attenuating the signal level by a predetermined amount includes attenuating the signal by at least 50 dB. 7. The method of claim 1, further comprising: displaying an attenuation indicator, the attenuation indicator indicating to a user that attenuation of at least one DTMF tone is being performed. 8. An apparatus for attenuating a dialing confirmation tone comprising: a dialing tone generator configured to: generate at least one dual-tone multiple frequency (DTMF) tone; and provide the at least one DTMF tone to a telephone line; a confirmation tone attenuator configured, in a first mode of operation, to: receive an enable signal from a tactile user input device; attenuate a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal; and provide the at least one attenuated dialing confirmation tone to an audio output device. 9. The apparatus of claim 8, wherein the confirmation tone attenuator is further configured, in a second mode of operation, to: receive a disable signal from the tactile user input device; and provide the at least one DTMF tone to the audio output device as at least one dialing confirmation tone in response to receiving the disable signal. 10. The apparatus of claim 8, wherein the tactile user input device includes a key. 11. The apparatus of claim 8, wherein the telephone line includes an analog telephone line. 12. The apparatus of claim 8, further comprising an attenuation indicator to indicate to a user that attenuation of at least one DTMF tone is being performed. 13. The apparatus of claim 8, wherein the audio output device includes an earpiece of a telephone set. 14. The apparatus of claim 8, wherein the predetermined amount of attenuation is at least 50 dB. 15. The apparatus of claim 8, wherein the apparatus is a telephone set. 16. A computer usable program product in a computer readable medium storing computer executable instructions for attenuating a dialing confirmation tone that, when executed, cause at least one processor to: receive an enable signal from a tactile user input device; generate at least one dual-tone multiple frequency (DTMF) tone; provide the at least one DTMF tone to a telephone line; attenuate a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal; and provide the at least one attenuated dialing confirmation tone to an audio output device. 17. The computer usable program product of claim 16, wherein the executable instructions further cause the at least one processor to: receive a disable signal from the tactile user input device; and provide the at least one DTMF tone to the audio output device as at least one dialing confirmation tone in response to receiving the disable signal. 18. The computer usable program product of claim 16, wherein the tactile user input device includes a key. 19. The computer usable program product of claim 16, wherein the executable instructions further cause the at least one processor to display an indicator of attenuation being performed on the at least one DTMF tone. 20. The computer usable program product of claim 16, wherein the predetermined amount of attenuation is at least 50 dB.
|
<SOH> BACKGROUND <EOH>Dual-Tone Multiple Frequency (DTMF) tones are required for dialing out and/or initiating a telephone call from a telephone set. DTMF signaling is used for telephone signaling from a telephone set over a telephone line to a call switching center. The DTMH signaling occurs in the voice-frequency band. During a dialing process by a user using touch-tone keys, the telephone set generates dialing confirmation tones that are played through the receiver earpiece of the telephone set so that dialing confirmation tones may be heard by the user. The dialing confirmation tones are intended for user convenience so that the user of the telephone set will be able to confirm that the telephone set has received the touch-tone key press. However, the loudness and duration of the dialing confirmation tones vary from one telephone set to another. Loud dialing confirmation tones may cause annoyance to a user, as well as be a disturbance to others. For example, in a calm and quiet environment, loud DTMF dialing confirmation tones may disturb the privacy of others in the environment. Continuous DTMF tones are required for some specific continuous operations, such as through remote access applications. For example, through remote access, a user needs to press and hold a specific key for a certain period of time to generate and send continuous tones in order to delete all stored messages in a remote voice mail system mailbox. In such situations, the dialing confirmation tones may be even more objectionable to the user.
|
<SOH> SUMMARY <EOH>Embodiments of the present invention provide for a method, system, and apparatus for attenuating and/or muting a dialing confirmation tone of a telephone set. A method for attenuating a dialing confirmation tone according to one embodiment includes receiving an enable signal from a tactile user input device, generating at least one dual-tone multiple frequency (DTMF) tone, and communicating the at least one DTMF tone to a telephone line. The method further includes attenuating a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal, and communicating the at least one attenuated dialing confirmation tone to an audio output device. An apparatus for apparatus for attenuating a dialing confirmation tone according to another embodiment includes a dialing tone generator configured to generate at least one dual-tone multiple frequency (DTMF) tone, and provide the at least one DTMF tone to a telephone line. The apparatus further includes a confirmation tone attenuator configured, in a first mode of operation, to receive an enable signal from a tactile user input device, attenuate a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal, and provide the at least one attenuated dialing confirmation tone to an audio output device. According to still another embodiment, a computer usable program product in a computer readable medium storing computer executable instructions for attenuating a dialing confirmation tone, when executed, cause at least one processor to receive an enable signal from a tactile user input device, generate at least one dual-tone multiple frequency (DTMF) tone, and provide the at least one DTMF tone to a telephone line. The executable instructions further cause the at least one processor to attenuate a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal, and provide the at least one attenuated dialing confirmation tone to an audio output device.
|
BACKGROUND Dual-Tone Multiple Frequency (DTMF) tones are required for dialing out and/or initiating a telephone call from a telephone set. DTMF signaling is used for telephone signaling from a telephone set over a telephone line to a call switching center. The DTMH signaling occurs in the voice-frequency band. During a dialing process by a user using touch-tone keys, the telephone set generates dialing confirmation tones that are played through the receiver earpiece of the telephone set so that dialing confirmation tones may be heard by the user. The dialing confirmation tones are intended for user convenience so that the user of the telephone set will be able to confirm that the telephone set has received the touch-tone key press. However, the loudness and duration of the dialing confirmation tones vary from one telephone set to another. Loud dialing confirmation tones may cause annoyance to a user, as well as be a disturbance to others. For example, in a calm and quiet environment, loud DTMF dialing confirmation tones may disturb the privacy of others in the environment. Continuous DTMF tones are required for some specific continuous operations, such as through remote access applications. For example, through remote access, a user needs to press and hold a specific key for a certain period of time to generate and send continuous tones in order to delete all stored messages in a remote voice mail system mailbox. In such situations, the dialing confirmation tones may be even more objectionable to the user. SUMMARY Embodiments of the present invention provide for a method, system, and apparatus for attenuating and/or muting a dialing confirmation tone of a telephone set. A method for attenuating a dialing confirmation tone according to one embodiment includes receiving an enable signal from a tactile user input device, generating at least one dual-tone multiple frequency (DTMF) tone, and communicating the at least one DTMF tone to a telephone line. The method further includes attenuating a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal, and communicating the at least one attenuated dialing confirmation tone to an audio output device. An apparatus for apparatus for attenuating a dialing confirmation tone according to another embodiment includes a dialing tone generator configured to generate at least one dual-tone multiple frequency (DTMF) tone, and provide the at least one DTMF tone to a telephone line. The apparatus further includes a confirmation tone attenuator configured, in a first mode of operation, to receive an enable signal from a tactile user input device, attenuate a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal, and provide the at least one attenuated dialing confirmation tone to an audio output device. According to still another embodiment, a computer usable program product in a computer readable medium storing computer executable instructions for attenuating a dialing confirmation tone, when executed, cause at least one processor to receive an enable signal from a tactile user input device, generate at least one dual-tone multiple frequency (DTMF) tone, and provide the at least one DTMF tone to a telephone line. The executable instructions further cause the at least one processor to attenuate a signal level of the at least one DTMF tone by a predetermined amount to produce at least one attenuated dialing confirmation tone in response to receiving the enable signal, and provide the at least one attenuated dialing confirmation tone to an audio output device. DESCRIPTION OF THE DRAWINGS A more complete understanding of the method and apparatus of the principles of the present invention may be obtained by reference to the following Detailed Description when taken in conjunction with the accompanying Drawings wherein: FIG. 1 is an illustration of an apparatus for attenuating a dialing confirmation tone in accordance with an embodiment of the invention; FIG. 2 is an illustration of an embodiment of a procedure for attenuating a dialing confirmation tone; and FIG. 3 is an illustration of another embodiment of a procedure for attenuating a dialing confirmation tone. DETAILED DESCRIPTION OF DRAWINGS Various embodiments of the present invention provide for a user of a telecommunication device, such as a telephone set, to attenuate and/or mute a dialing confirmation tone. In a particular embodiment, the dialing confirmation tone is a dual-tone multiple frequency (DTMF) confirmation tone. In accordance with various embodiments, the telecommunication device is a telephone set coupled to a plain old telephone service (POTS) or public switched telephone network (PSTN). In a particular embodiment, the telecommunication device is coupled to an analog line of a telecommunication network. In various embodiments, a user is provided with the option on the telephone set of attenuating the volume level of the dialing confirmation tones provided to an earpiece or speaker of the telephone set when desired by the user. In a particular embodiment, the telephone set is provided with a hard key. When the hard key is pressed by a user, any dialing confirmation tones provided to the earpiece are attenuated. In another embodiment, the telephone set is provided with a program mode in which the telephone set is placed into a confirmation tone attenuation mode or mute mode whenever a particular sequence is entered by the user on the touch pad of the telephone set. In the confirmation tone attenuation mode, any dialing confirmation tones provided to the earpiece of the telephone set are attenuated. The description that follows is directed to one or more embodiments, and should not be construed as limiting in nature. FIG. 1 is an illustration of an apparatus for attenuating a dialing confirmation tone in accordance with an embodiment of the invention. For the purposes of this description, attenuation may include muting the dialing confirmation tones through attenuating the DTMF signals to a level at which the signals are inaudible or preventing the DTMF signals from being communicated to the earpiece or speaker. A telephone set 100 may include a processor 102, a dual-tone multiple frequency (DTMF) tone generator 104, a confirmation tone attenuator 108, a mode key 110, and a key pad 114. In various embodiments, the telephone set 100 may included a corded telephone set coupled to a telephone line or a cordless telephone set having an associated base unit coupled to a telephone line. In various embodiments, the telephone set 100 may include either a digital or analog telephone set. The key pad 114 is coupled to the processor 102, and the processor 102 is further coupled to an input of the DTMF tone generator 104. An output of the DTMF tone generator 104 is coupled a DTMF tone dialing output 106 and an input of the confirmation tone attenuator 108. An output of the confirmation tone attenuator 108 is coupled to a receiver audio output 112 of the telephone set 100. In at least one embodiment, the receiver audio output 112 is coupled to an earpiece in a receiver of the telephone set 100. In other embodiments, the receiver audio output 112 is coupled to a headset coupled to the telephone set 100. In still other embodiments, the receiver audio output 112 may be coupled to any other type of audio output device. The mode key 110 is coupled to the confirmation tone attenuator 108 and provides an enable/disable signal to the confirmation tone attenuator 108 from the mode key 110 responsive to user input. In at least one embodiment, the mode key 110 is a key or button mounted on the telephone set 100. In other embodiments, the mode key 110 is a part of the keypad 114. Although the illustrated embodiment describes the use of a mode key 110 for user input, it should be understood that other embodiments may use other types of tactile user input devices to send the enable/disable signal to the confirmation tone attenuator 108. In accordance with various embodiments, a tactile user input device is an input device that is operated by touch by a user. In an example mode of operation, a user of the telephone set 100 presses the mode key 110, and the mode key 110 provides an enable signal to the confirmation tone attenuator 108. In response to receiving the enable signal, the confirmation tone attenuator 108 is placed in a confirmation tone attenuation mode. To initiate the call, the user presses one or more keys on the key pad 114. In response to each key press, the processor 102 instructs the DTMF tone generator 104 to generate DTMF tones corresponding to the key press. The DTMF tones are provided to the DTMF tone dialing output 106 and the input of the confirmation tone attenuator 108, which attenuates the DTMF tones prior to being communicated to the receiver audio output 112. The DTMF tone dialing output 106 is coupled to the telephone line, and the DTMF tones provided to the DTMF tone dialing output 106 are transmitted over the telephone line to a switching center to connect the telephone call. Although the embodiment of FIG. 1 is illustrated as using DTMF tone generator 104, it should be understood that other types of dialing tone generators could be used in other embodiments. More particularly, in the confirmation tone attenuation mode, a signal level of the DTMF tones provided to the input of the confirmation tone attenuator 108 are attenuated by a predetermined amount by the confirmation tone attenuator 108 to generate attenuated dialing confirmation tones. The attenuated dialing confirmation tones are output by the confirmation tone attenuator 108 to the receiver audio output 112. The procedure is repeated for each key press by the user on the key pad 114. In at least one embodiment of the invention, the confirmation tone generator 108 attenuates the DTMF tones by at least 50 dB to 60 dB compared to the signal level of the generated DTMF tones to produce the attenuated dialing confirmation tones. In a particular embodiment, the signal level of the attenuated dialing confirmation tones produced by the confirmation tone generator 108 are attenuated to an amount such that the attenuated dialing confirmation tones are substantially imperceptible to the user of the telephone set 100. In an alternative embodiment, an attenuation level of the dialing confirmation tones is selectable by the user of the telephone set 100 via one or more keys, knobs, or other input elements. In still another alternative embodiment, the confirmation tone attenuator 108 may function to electrically disconnect the output of the DTMF tone generator 104 from the receiver audio output 112 such that no dialing confirmation tones are provided to the receiver audio output 112. In this alternative embodiment, the dialing confirmation tones may be referred to as muted. If the user again presses the mode key 110, the mode key 110 provides a disable signal to the confirmation tone attenuator 108. In response to receiving the disable signal, the confirmation tone attenuator 108 is placed in a normal mode. In the normal mode, the DTMF tones produced by the DTMF tone generator 104 are not attenuated by the confirmation tone generator 108, and the dialing confirmation tones are provided to the receiver audio output 112 at substantially the same signal level as the generated DTMF tone. An example of a situation in which a user may wish to return to the normal mode during an established call is when a user wishes to forward the established call to an automated key pad response system where the DTMF confirmation tone is desired to be heard. In accordance with various embodiments, the telephone set 100 returns to the normal mode 110 automatically after a call has ended. In various embodiments, the default mode of the telephone set 100 is the normal mode. In at least one embodiment, the telephone set 100 includes an indication of the current mode of the confirmation tone attenuator 108. In one embodiment, the telephone set 100 includes an attenuation indicator such as a status light, a single or multi-color light emitting diode (LED), that indicates whether the confirmation tone attenuation mode is activated. In another embodiment, the telephone set 100 is provided with a display that indicates whether the confirmation tone attenuator 108 is in the normal mode or the confirmation tone attenuation mode. It should be understood that one or more of the DTMF tone generator 104 and the confirmation tone attenuator 108 can include hardware components, software components or a combination of hardware and software components. FIG. 2 is an illustration of an embodiment of a procedure for attenuating a dialing confirmation tone. The procedure 200 starts in step 205 in which the confirmation tone attenuator 108 begins in the normal mode in which dialing confirmation tones are not attenuated. In step 210, the user puts the telephone set 100 into a program mode. In various embodiments, the user may put the telephone set 100 into the program mode by pushing one or more keys on the key pad 114. In step 215, the user enters a DTMF confirmation tone attenuation option code using the key pad 114 to enable the confirmation tone attenuate mode. In a particular embodiment, the user enters at least two digits before the confirmation tone attenuator 108 enters the confirmation tone attenuation mode. In step 220, the confirmation tone attenuation mode is enabled in response to the entering of the DTMF confirmation tone attenuation option code by the user. In the confirmation tone attenuation mode, the signal level of DTMF tones provided to the input of the confirmation tone attenuator 108 are attenuated by a predetermined level by the confirmation tone attenuator 108 to generate attenuated dialing confirmation tones. The attenuated dialing confirmation tones are output by the confirmation tone attenuator 108 to the receiver audio output 112. In an alternative embodiment, the confirmation tone attenuator 108 may function to electrically disconnect the output of the DTMF tone generator 104 from the receiver audio output 112 such that no dialing confirmation tones are provided to the receiver audio output 112. In step 225, the user of the telephone set 100 initiates a telephone call by dialing on the key pad 114. In response to the telephone set 100 being in the confirmation tone attenuation mode, the dialing confirmation tones generated by the user dialing on the key pad 114 and presented to the user via the earpiece are attenuated. During the telephone call, any dialing confirmation tones generated by the user pressing any keys on the key pad 114 will continue to be attenuated. In step 230, the call is disconnected by the user hanging up the telephone set 100. Alternately, the call can be disconnected by a called party disconnection of the call. In step 235, the telephone set 100 returns to the default mode. In the default mode, DTMF tones generated by the DTMF tone generator 104 are not attenuated by the confirmation tone generator 108, and the dialing confirmation tones are provided to the receiver audio output 112 at substantially the same signal level as the generated DTMF tone. In an alternative embodiment, step 235 is omitted and the telephone set 100 remains in the confirmation tone attenuation mode until the user changes the mode to the default mode. The procedure 200 ends in step 240. The various steps of procedure 200 have been chosen and described only as exemplary and are not limiting on the illustrative embodiments. An implementation of the illustrative embodiments may alter, combine, delete or augment these steps without departing from the scope of the illustrative embodiments. FIG. 3 is an illustration of another embodiment of a procedure for attenuating a dialing confirmation tone. The procedure 300 starts at step 305. At step 310, a user of the telephone set 100 presses a hard key on the telephone set 100. In response to the user pressing the hard key, the confirmation tone attenuation mode is enabled in step 315. In step 320, the user of the telephone set 100 initiates a telephone call by dialing on the keypad 114. In response to the telephone set 100 being in the confirmation tone attenuation mode, the dialing confirmation tones generated by the user dialing on the key pad 114 and presented to the user via the earpiece are attenuated. During the telephone call, any dialing confirmation tones generated by the user pressing any keys on the key pad 114 will continue to be attenuated while the telephone set is in the confirmation tone attenuation mode. In step 325, a determination is made regarding if the user has pressed the hard key again during the call. If it is determined that the user has not pressed the hard key again, the call continues until step 330. If it is determined in step 325 that the user has pushed the hard key, the attenuation mode is toggled between the confirmation tone attenuation mode and the default mode in step 335, and the call continues until step 330. In step 330, the user hangs up the call. In alternative embodiments, the user may toggle between the confirmation tone attenuation mode and the default mode a multiple of times during a call by pressing the hard key on the telephone set 100. After user hang-up of the call in step 330, the telephone set 100 returns to default mode in step 340. In the default mode, DTMF tones generated by the DTMF tone generator 104 are not attenuated by the confirmation tone attenuator 108, and the dialing confirmation tones are provided to the receiver audio output 112 at substantially the same signal level as the generated DTMF tones. In an alternative embodiment, step 340 is omitted and the telephone set 100 remains in the confirmation tone attenuation mode until the user changes the mode to the default mode. The procedure 300 ends in step 345. The procedure 300 illustrated in FIG. 3 allows a user of the telephone set 100 to toggle between the confirmation tone attenuation mode and the default mode during a telephone call. For example, an established call can be forwarded to an automated key pad response system where allowing a user to hear DTMF confirmation tones may be desired. The various steps of procedure 300 have been chosen and described only as exemplary and are not limiting on the illustrative embodiments. An implementation of the illustrative embodiments may alter, combine, delete or augment these steps without departing from the scope of the illustrative embodiments. Although embodiments of the present embodiments have been illustrated with respect to a telephone set, it should be understood that the principles described herein are applicable to other telecommunication devices. For example, the principles described herein can be applied to computer modems. The illustrative embodiments can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. Furthermore, the illustrative embodiments can take the form of a computer program product (e.g., soft-phone) accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer-readable medium can be any tangible apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W and DVD. Further, a computer storage medium may contain or store a computer-readable program code such that when the computer-readable program code is executed on a computer, the execution of this computer-readable program code causes the computer to transmit another computer-readable program code over a communication link. This communication link may use a medium that is, for example without limitation, physical or wireless. The above description has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the illustrative embodiments in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art.
|
H
|
H04
|
H04M
|
3
|
00
|
|||
12001360
|
US20080292635A1-20081127
|
Allergenic latex protein
|
ACCEPTED
|
20081112
|
20081127
|
[]
|
A61K39395
|
["A61K39395", "C07K1400", "G01N3300", "G01N3353", "A61P3700", "C07K100", "C07K1618", "G01N33566"]
|
7732566
|
20071211
|
20100608
|
530
|
300000
|
96134.0
|
ROONEY
|
NORA
|
[{"inventor_name_last": "Mad Arif", "inventor_name_first": "Siti Arija", "inventor_city": "Sungai Buloh", "inventor_state": "", "inventor_country": "MY"}, {"inventor_name_last": "Chew", "inventor_name_first": "Nyu Ping", "inventor_city": "Sungai Buloh", "inventor_state": "", "inventor_country": "MY"}, {"inventor_name_last": "Yeang", "inventor_name_first": "Hoong Yeet", "inventor_city": "Sungai Buloh", "inventor_state": "", "inventor_country": "MY"}]
|
The present invention relates to a protein found in natural rubber that can induce an allergic reaction in persons who have been sensitised to it. The invention provides for the process of isolating and purifying the protein and describes the characteristics of the protein, including its molecular weight, isoelectric point, amino acid sequence and allergenicity. The invention also describes the isolation and cloning a the DNA that encodes the protein. The production of the recombinant version of the protein using a protein expression vector is described.
|
1. An isolated protein comprising an amino acid sequence as set forth in SEQ ID NO:5, wherein said protein is capable of inducing an allergic reaction to latex in a person sensitized to said protein. 2. The protein of claim 1, consisting of an amino acid sequence as set forth in SEQ ID NO:5. 3. A peptide comprising a portion of the protein of claim 1, wherein said peptide is capable of inducing an allergic reaction in a person sensitized to said protein. 4. A method for identifying a compound capable of binding to the protein of claim 1, said method comprising the steps of: (a) contacting said protein, or a cell expressing said protein, with a test compound under conditions suitable for binding; and (b) detecting binding of the test compound to said protein. 5. A method for identifying a compound capable of binding to a nucleic acid molecule encoding the protein of claim 1, said method comprising the steps of: (a) contacting said nucleic acid molecule with a test compound under conditions suitable for binding; and (b) detecting binding of the test compound to said nucleic acid molecule. 6. An isolated protein capable of inducing an allergic reaction in a person sensitized to said protein, wherein said protein has a molecular weight of about 42,000 Daltons, has an isoelectric point of about 4.7, binds with IgE of patients sensitized to the protein and comprises an amino acid sequence as set forth in SEQ ID NO:5. 7. A method of producing the protein of claim 1, said method comprising the steps of: a) centrifuging latex to obtain the bottom fraction; b) freeze-thawing the bottom fraction to obtain latex B-serum; and c) isolating and purifying said protein from the B-serum obtained in step (b). 8. The method of claim 7, wherein the isolation and purification of said protein are carried out via a series of chromatographic separations. 9. The method of claim 8, wherein said chromatographic separations comprise ion exchange chromatography or gel filtration. 10. An antibody that selectively binds to the protein of claim 1. 11. The antibody of claim 10, wherein said antibody is a monoclonal antibody. 12. The antibody of claim 10, wherein said antibody is a polyclonal antibody. 13. An immunoassay for the presence of antibodies to allergenic latex protein in a sample, said immunoassay comprising the steps of: (a) providing the protein of claim 1; (b) reacting a sample of antibodies with said protein; and (c) detecting a reaction between said protein and said sample. 14. A method of providing immunotherapy for a patient who is susceptible to an allergic reaction to latex comprising administering to the patient an immunotherapeutically effective amount of the antibody of claim 10.
|
<SOH> 2. BACKGROUND OF THE INVENTION <EOH>By the late 1980s and into the 90s, reports began to be received with increasing frequency in Europe and America of allergic reactions occurring among users of surgical and examination gloves made of latex and among spina bifida patients. The significant increase in the number of reports of latex allergy in the last decade has also been attributed to increased usage of latex gloves in healthcare in tandem with the rising cases of AIDS. Sensitisation to latex among healthcare workers is clearly work-related, the main cause being latex gloves, or specifically, the allergenic protein in latex gloves. Nevertheless, numerous cross-sensitivities between latex protein allergens and various food and pollen allergens are known. It is therefore not improbable that many latex-allergic patients may have been initially sensitised not only by proteins from latex products, but also by proteins from other sources. There are hundreds of proteins found in natural rubber latex. Of these, only a small handful is allergenic (able to induce allergy). There has been much interest in identifying the proteins in Hevea latex responsible for latex allergy and considerable effort is expended on isolating and purifying the allergenic proteins from Hevea latex or latex products. Other than from the academic standpoint, elucidation of the major allergens in latex would enable antibodies to be developed against these proteins. Availability of the antibodies would facilitate the development of latex immunoassays, both for laboratory and commercial use. There are two main types of latex immunoassays
|
<SOH> 3. SUMMARY OF THE INVENTION <EOH>According to the most general aspect of the present invention, there is provided a protein originating from latex that can induce an allergic reaction in persons sensitized to the protein. Preferably, the protein or its molecular variant characterized in that the protein has the following properties: a) has a molecular weight of about 42,000 Dalton; b) has an isoelectric point of about 4.7; c) binds with IgE of patients sensitized to the protein; and d) contains the amino acid sequence as in FIG. 2 or minor variations of these amino acid sequence that do not result in the allergenic properties of the protein being substantially altered. The second aspect of the present invention provides for a process for obtaining a protein or its molecular variant where the process comprises the following steps: a) centrifuging the latex for obtaining the bottom fraction; b) freeze-thawing the bottom fraction for obtaining the latex B-serum; and c) isolating and purifying the protein from the B-serum obtained in (b). The third aspect of the present invention provides for a peptide that is derived from the protein where the peptide has similar allergenic properties as the protein. Further, the present invention provides for a DNA sequence encoding the protein or a portion of the protein where the DNA sequence (SEQ ID NO:1) is as in FIG. 1 or minor variations of this sequence. Also, the present invention provides a method for the production of a protein or its molecular variants in recombinant form by inserting the DNA encoding the protein or a variant of the protein into an appropriate vector and inducing the vector to express recombinant protein or in recombinant form of the said variant of the protein, whereby in this case, the amino acid sequence (SEQ ID NO:5) of the above translated DNA sequence is as in FIG. 2 .
|
CROSS REFERENCE TO RELATED APPLICATIONS The present application is a divisional application of U.S. application Ser. No. 10/789,312, filed Feb. 27, 2004 and entitled ALLERGENIC LATEX PROTEIN, which is hereby incorporated by reference herein. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT N/A 1. TECHNICAL FIELD OF THE INVENTION The present invention relates in general to a protein. 2. BACKGROUND OF THE INVENTION By the late 1980s and into the 90s, reports began to be received with increasing frequency in Europe and America of allergic reactions occurring among users of surgical and examination gloves made of latex and among spina bifida patients. The significant increase in the number of reports of latex allergy in the last decade has also been attributed to increased usage of latex gloves in healthcare in tandem with the rising cases of AIDS. Sensitisation to latex among healthcare workers is clearly work-related, the main cause being latex gloves, or specifically, the allergenic protein in latex gloves. Nevertheless, numerous cross-sensitivities between latex protein allergens and various food and pollen allergens are known. It is therefore not improbable that many latex-allergic patients may have been initially sensitised not only by proteins from latex products, but also by proteins from other sources. There are hundreds of proteins found in natural rubber latex. Of these, only a small handful is allergenic (able to induce allergy). There has been much interest in identifying the proteins in Hevea latex responsible for latex allergy and considerable effort is expended on isolating and purifying the allergenic proteins from Hevea latex or latex products. Other than from the academic standpoint, elucidation of the major allergens in latex would enable antibodies to be developed against these proteins. Availability of the antibodies would facilitate the development of latex immunoassays, both for laboratory and commercial use. There are two main types of latex immunoassays 1. Immunoassays for Latex Allergy Diagnosis These diagnostics are used to determine if someone is allergic or sensitized to latex. The assays can either be of the in vitro format (usually a serological test) or of the in vivo format (skin prick tests). These assays are used in research and in healthcare. 2. Immunoassays for the Quantitation of Latex Allergens in Manufactured Products These quantitative assays determine the amount of allergenic proteins present in latex products. They are used for testing latex products such as latex gloves to determine the content of extractable latex allergens. Such immunoassays would be very valuable in latex product manufacture, particularly in the aspects of standardisation and quality control and quality assurance. The prospective customers for such immunoassays would be latex product manufacturers and regulatory agencies charged with the responsibility of ensuring product specification compliance. Identification of the major latex allergens serves another useful function in healthcare. Purified latex allergens can be used in immunotherapy to de-sensitise latex allergic patients. When successfully undertaken, the patient no longer develops an allergic reaction to latex. This is especially important where the patient works in an environment (e.g. in healthcare) where latex products are ubiquitous. Today, the International Union of Immunological Societies (IUIS) recognises ten latex allergens, Hev b 1 to Hev b 10. (There are other latex proteins under consideration by the IUIS.) Although there is effort being made to look for significant latex protein allergens, many researchers believe that most of the major latex protein allergens have been accounted for. In 1995, Dr Donald Beezhold in his paper presented at Int Conf on Latex Protein Allergy: The Latest Position announced a new latex allergen that had partial protein homology to patatin, the major storage protein of potatoes. This 43 kDa protein is later assigned the WHO/IUIS name Hev b 7. When a recombinant version of Hev b 7 became available, it is found to be reactive with IgE from latex allergic patients. However, the proportion of patients that are sensitised to recombinant Hev b 7 is much lower than expected. Western blots that showed an active protein band around 43 kDa protein is much more commonly encountered than could be explained by IgE binding to Hev b 7. Hence, the recombinant Hev b 7 could not account for the very frequent occurrence of latex sensitivity to a protein of about 43 kDa. It is, therefore, possible that another unknown latex allergen of around 43 kDa existed. The search for this new and unknown protein has culminated in the present invention. This protein is allergenic in nature in that contact with allergenic latex protein (ALP) can induce an allergic reaction in persons sensitized to this protein. 3. SUMMARY OF THE INVENTION According to the most general aspect of the present invention, there is provided a protein originating from latex that can induce an allergic reaction in persons sensitized to the protein. Preferably, the protein or its molecular variant characterized in that the protein has the following properties: a) has a molecular weight of about 42,000 Dalton; b) has an isoelectric point of about 4.7; c) binds with IgE of patients sensitized to the protein; and d) contains the amino acid sequence as in FIG. 2 or minor variations of these amino acid sequence that do not result in the allergenic properties of the protein being substantially altered. The second aspect of the present invention provides for a process for obtaining a protein or its molecular variant where the process comprises the following steps: a) centrifuging the latex for obtaining the bottom fraction; b) freeze-thawing the bottom fraction for obtaining the latex B-serum; and c) isolating and purifying the protein from the B-serum obtained in (b). The third aspect of the present invention provides for a peptide that is derived from the protein where the peptide has similar allergenic properties as the protein. Further, the present invention provides for a DNA sequence encoding the protein or a portion of the protein where the DNA sequence (SEQ ID NO:1) is as in FIG. 1 or minor variations of this sequence. Also, the present invention provides a method for the production of a protein or its molecular variants in recombinant form by inserting the DNA encoding the protein or a variant of the protein into an appropriate vector and inducing the vector to express recombinant protein or in recombinant form of the said variant of the protein, whereby in this case, the amino acid sequence (SEQ ID NO:5) of the above translated DNA sequence is as in FIG. 2. 4. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 shows the DNA sequence of the full length cDNA clone encoding the ALP. FIG. 2 shows the amino acid sequence of the ALP derived from the translation of the cDNA clone encoding the ALP. FIG. 3 shows the matrix assisted laser desorption ionisation mass spectrometry (MALDI-MS) spectrum of the allergenic latex protein, ALP. FIG. 4 shows a Western blot of ALP after separation of the protein by SDS-polyacrylamide gel electrophoresis. The protein is stained with Coomassie Blue to show the presence and electrophoretic migration of ALP (lane 2). Binding of human IgE of patients sensitised to ALP on the Western blot (lane 3), polyclonal antibodies developed against ALP (lane 4), and a monoclonal antibody developed against ALP (lane 5). FIG. 5 shows a Western blot of ALP after separation of the protein by SDS-polyacrylamide gel electrophoresis. The protein is stained with Coomassie Blue to show the presence and electrophoretic migration of ALP (lane 2). A reaction specific for the presence of carbohydrates is carried out to demonstrate glycosylation of ALP (lane 3). FIG. 6 shows a Western blot of the recombinant MBP-ALP fusion protein after separation by SDS-PAGE. The protein is stained with Coomassie Blue to show the electrophoretic migration of the recombinant ALP fusion protein (lane 3). Binding of recombinant ALP to monoclonal (Lane 4) and polyclonal antibodies (lane 5) developed against native ALP is also shown. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a protein isolated from the B-serum of centrifuged latex obtained by tapping the rubber tree, Hevea brasiliensis. The following description details how the protein can be isolated, purified and characterized, and how it might be used in cloning the cDNA encoding the protein, how recombinant versions of the protein can be obtained, how antibodies might be developed from the protein and how the protein can be used in immunoassay and immunotherapy. Example 1 Protein Isolation and Purification Fresh latex from Hevea brasiliensis trees (clone RRIM 600) is collected into chilled containers. The latex is centrifuged at 19,000 r.p.m. (43,000 g) on a Sorvall RC 5C high-speed centrifuge for 1 h at 4-7° C. to separate it into three main fractions: the top fraction which is the rubber cream, the heavy bottom fraction and the C-serum located in between. Latex B-serum is prepared based on the method of Hsia (1958) Trans Instn Rubb Ind. The latex bottom fraction from centrifuged latex is washed by re-suspension in 0.4M mannitol and recovered by centrifugation. The washed bottom fraction is then subjected to repeated freezing and thawing to rupture the lutoids that are its main constituents. The lutoidic fluid, the B-serum, is recovered as the supernatant after re-centrifugation. B-serum is dialysed overnight against 0.3 mM sodium borate and 0.016 M boric acid pH 7 in the cold room. This is followed with filtration through Whatman No. 1 filter paper. Ten ml of the filtered B-serum is loaded onto carboxymethyl cellulose CM32 (Whatman) column (20 cm×1.5 cm) equilibrated with 0.09 M sodium borate and 0.016 M boric acid, pH 8.6. Proteins are eluted with a gradient of 150 ml of 0.09M sodium borate and 0.016 M boric acid, pH 8.6 against 150 ml of 0.9M sodium borate and 0.16 M boric acid, pH 8.6. Two ml fractions are collected at a rate of 2.6 min/fraction. The unretarded materials (i.e. fractions 3 to 11) are loaded into a DE 52 (Whatman) column (12 cm×1.5 cm) equilibrated with 0.1 M Tris-HCl, pH 8. The protein is eluted with a gradient of 0-0.5 M NaCl in the same buffer. Fractions containing proteins of about 43 kDa, as determined by SDS-polyacrylamide gel electrophoresis, are tested for immunoglobulin IgE binding with serum latex-allergic patients. The fractions containing ALP are identified and pooled. The approximate molecular weight of ALP determined by comparing the migration of ALP with that of various calibration markers is 42 kDa (FIG. 4 lane 2). Example 2 Molecular Weight and Isoelectric Point Determination and Amino Acid Sequencing The accurate molecular weight of the allergenic latex protein, ALP, determined by mass spectrometry is 42975. The matrix assisted laser desorption ionisation mass spectrometry (MALDI-MS) spectrum of the protein sample is shown in FIG. 3. The isoelectric point (pI) of ALP is determined by isoelectric focusing (IEF). The migration of the protein on the IEF gel is measured and compared with protein calibration standards of known pI. The pI of ALP is estimated to be 4.7. The protein is found to be blocked at the N-terminal. In situ digestion by trypsin resulted in several fragments. Partial amino acid sequences are obtained for three of these fragments. Sequence 1: YLDVQYSQFR (SEQ ID NO:7) Sequence 2: YSLFSEPEK (SEQ ID NO:8) Sequence 3: LPTTIIPAHGGFSSR (SEQ ID NO:9) where the letters of the alphabet are accepted abbreviations for individual amino acids. Sequence 1 is derived from a peptide of 1319 Da. The amino acid sequence data obtained by mass spectrometry is compared against the protein sequence database of the National Centre for Biotechnology Information (NCBI), USA, using the BLAST algorithm. The search revealed that the amino acid sequences had partial homology with the “early nodule-specific protein” of Glycine max. Sequence 2 is derived from a peptide of 1100 Da. The sequence showed partial homology with “early nodule-specific protein” of Medicago truncatula. Sequence 3 is derived from a peptide of 1556 Da. The sequence showed partial homology with “early nodule-specific protein” of Glycine max. Example 3 Determination of Glycosylation of ALP To demonstrate that a carbohydrate is bound to the ALP protein (rendering ALP a ‘glycosylated protein’ or glycoprotein), purified proteins are separated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) on 15% gels and transferred electrophoretically to a nitrocellulose membrane to obtain a Western Blot. The membrane is washed with phosphate buffered saline (PBS) and then immersed into 10 mM sodium periodate/EDTA with agitation in the dark for 20 min. Following this, the membrane is washed three times with PBS for 10 minutes each cycle. The membrane is next transferred to a solution made up of biotin-hydrazide in sodium acetate/EDTA and agitation is carried out for 60 min. After washing three cycles with Tris-buffered saline (TBS), the membrane is blocked and then washed over another three cycles with TBS. The membrane is then immersed in strepavidin-alkaline phosphatase for 60 min. After another three cycles of washing with TBS, the membrane is immersed in a solution of 5-bromo-4-chloro-3-indolyl phosphate/nitro blue tetrazolium (BCIP/NBT) substrate. The appearance of the coloured alkaline phosphatase reaction product indicated the presence of the carbohydrate component of the glycoprotein (FIG. 5). Example 4 Production of Antibodies Against ALP Both polyclonal antibodies and monoclonal antibodies are successfully developed against ALP. Polyclonal Antibodies Against ALP A pure preparation of ALP (approximately 0.5 ml of 0.5 mg ALP/ml) in phosphate buffered saline (PBS) is mixed with an equal volume of complete Freunds' adjuvant and this antigen mixture is injected subcutaneously into the back of rabbits. Seven booster dose of the same antigen formulation, but with incomplete Freunds' adjuvant, are administered at two week intervals. Blood is drawn from the rabbits to obtain the anti-serum that contained polyclonal antibodies against ALP. To demonstrate polyclonal antibody binding to ALP, a Western blot of the protein on to nitrocellulose membrane is prepared as in Example 3. The nitrocellulose membrane is blocked with 5% non-fat milk in PBS and then incubated for 90 min with anti-ALP polyclonal antibodies (diluted 1:800 in PBS-milk) as the primary antibody. After three cycles of washing with PBS-milk, the nitrocellulose membrane is incubated for 1 h with the secondary antibody, anti-rabbit IgG conjugated to alkaline phosphatase. After a further three cycles of washing with PBS-milk, the nitrocellulose membrane is incubated for 10 min in Tris buffered saline (TBS) before being immersed in 5-bromo-4-chloro-3-indolyl phosphate/nitro blue tetrazolium (BCIP/NBT) substrate to generate the coloured alkaline phosphatase reaction product. The binding of polyclonal antibodies to ALP on a Western blot of the protein after separation of the protein by SDS-polyacrylamide gel electrophoresis is shown in FIG. 5 (lane 4). Monoclonal Antibodies Against ALP Spleen cells from a Balb/c mouse immunized with latex C-serum are fused with mouse myeloma cells following protocols previously described by Kohler and Milstein (12,13). The resulting hybridoma cells are screened for antibodies specific to C-serum proteins. Selected hybridomas are re-cloned twice and monoclonal antibodies secreted are used either in unpurified form in hybridoma cell supernatants or as preparations purified by affinity chromatography. To demonstrate monoclonal antibody binding to ALP, a Western blot of the protein on to nitrocellulose membrane and processed as for the polyclonal antibody, except that monoclonal antibody against ALP is used as the primary antibody, while anti-mouse IgG conjugated to alkaline phosphatase is used as the secondary antibody. The binding of monoclonal antibodies to ALP on a Western blot of the protein after separation of the protein by SDS-polyacrylamide gel electrophoresis is shown in FIG. 4 (lane 5). Recombinant Monoclonal Antibodies Against ALP An anticipated variation of the conventional monoclonal antibody is the recombinant antibody whereby the antibody can be generated using a specific segment of DNA that encodes the amino acid sequence of the antibody or a functional fragment of the antibody such as a single chain variable fragment. There are several approaches to the development of recombinant antibodies, of which an example is outlined here. Antibody gene libraries are first constructed, for example, by PCR-amplification from B-lymphocyte cDNA. To screen these libraries, antibodies are displayed on the surface of microorganisms containing the antibody's gene (phage display). They are challenged with the antigen protein to identify specific clones producing an antibody that bind to this protein. Once the organism bearing the antibody gene is identified, specific clones can then be amplified and used to produce the antibody fragment in E. coli or other suitable organism. Example 5 Demonstration of Protein Allergenicity A Western blot of the purified protein is incubated with blood serum from latex allergic patients to determine if IgE (the immunoglobulin that mediates the allergic reaction) bound to the protein. Binding of IgE to the protein indicated that the protein is allergenic. To detect protein-IgE binding in Western blots, a similar procedure as in Example 2 is followed, except that the nitrocellulose membrane is incubated overnight with serum pooled from several latex-allergic patients (diluted 1:5.25 in PBS-milk and 0.05-6 sodium azide) as the primary antibody. Anti-human IgE conjugated to alkaline phosphatase served as the secondary antibody. The binding of human IgE to ALP on a Western blot of the protein after separation of the protein by SDS-polyacrylamide gel electrophoresis is shown in FIG. 4 (lane 3). Example 6 Preparation and Cloning of the cDNA Encoding ALP The complementary DNA (cDNA) encoding the amino acid sequence of ALP can be cloned and multiplied in a host such as a micro-organism. The micro-organism can be selected from the group consisting of bacteria, yeast, and viruses. Higher plant cells can also be used as vectors. The ALP protein, in recombinant form, can then be synthesised in the same host or in an alternative host. The following is a description of the method used to clone the cDNA of ALP. Standard methods are used in the preparation and purification of DNA, mini- and maxipreps, DNA purification, restriction endonuclease digestions, agarose gel electrophoresis, ligations, transformations and poly(A)+ mRNA isolation by oligo(dT) cellulose column chromatography. Preparation of Latex mRNA Latex is collected by tapping the Hevea brasiliensis tree. Before the tree is tapped, it is fitted with a sterilised drainage spout. Immediately upon tapping, the incision and spout are washed with about 20 ml of 2×RNA extraction buffer (0.1 mol Tris-HCl, 0.3 mol LiCl, 0.01 mol EDTA, 10% SDS, pH 9.5). The latex is then washed down with 100 ml of RNA extraction buffer to a total collected volume of 200 ml in a sterile conical flask. In the laboratory, the latex is mixed well and centrifuged in polyallomer tubes at 112,700 g for 30 minutes at 15° C. The aqueous phase is gently decanted into sterile centrifuge tubes and subsequent processing of the aqueous phase to isolate total RNA is performed according to the method of Prescott and Martin (1987) Plant Mol Biol Rep. Synthesis of ALP cDNA First strand cDNA synthesis is prepared by reverse transcribing 1 microgram of total latex RNA in 20 μl volume using the GeneRacer™ Kit (Invitrogen, USA) as per the vendor's instructions. Synthesis of cDNA is accomplished by PCR amplification. The cDNA is amplified by PCR without prior purification. Each reaction is performed in a 50 μl volume containing 2 μl of the first strand reaction above, 12.5 μM of GeneRacer™ 3′ Primer (5′-GCTGTCAACGATACGCTACGTAACG-3′ (SEQ ID NO:10) where A, G, C and T are the abbreviations for the nucleotides bases adenine, guanine, cytosine and thymine respectively), 12.5 μM of specific primer, 0.2 mMol dATP, 0.2 mMol dTTP, 0.2 mMol dCTP, 0.2 mMol dGTP, pH 7.5, 1 unit of Taq High Fidelity (Roche Diagnostics GmbH), 10 mM Tris-Hcl, 1.5 mM MgCl2, 50 mM KCl, pH 8.3, and overlayed with 50 μl of mineral oil. The PCR reaction took place in a thermocycler following the manufacturer's instructions. A second round of PCR is performed as previously but using 5 μl of the first round PCR as the template. 20 μl of the PCR amplification product is used for analysis on a 1.0% agarose gel stained with ethidium bromide. Cloning of ALP cDNA. The PCR product (about 1.5 Kb, in size) is ligated into the TOPO® vector (Invitrogen, USA) as per the vendor's instructions. The ligate (2 μl) is used for the transformation of One Shot® TOP10 Chemically Competent Escherichia coli (Invitrogen, USA) to ampicillin resistance. After incubating overnight at 37° C. in agar medium containing ampicillin (100 μg/ml), transformants were picked by Xgal (80 μg/ml)/IPTG (3 mmol/L) colour selection. The picked clones are screened by miniprep assay using the Wizard® SV Minipreps DNA Purification System (Promega, USA) as per the vendor's instructions. 1 ug of the selected clones are then sent for nucleic acid sequencing. The DNA sequences (1394 basepairs, FIG. 1) are translated into the amino acids that they encoded (FIG. 2). The amino acid sequence encompassed the following segments: 1) ctaccaactactattatacctgctcatggtggatttagt (at position 384 to 422) (SEQ ID NO:2) encodes the peptide LPTTIIPAHGGFS (SEQ ID NO:6) 2) taccttgatgtccaatattcgcaattccgg (at position 429 to 458) (SEQ ID NO:3) encodes the peptide YLDVQYSQFR (SEQ ID NO:7) 3) tattctttattcagtgagccagaaaaa (at position 897 to 923) (SEQ ID NO:4) encodes the peptide YSLFSEPEK (SEQ ID NO:8) where a, g, c and t are the abbreviations for the nucleotides bases adenine, guanine, cytosine and thymine respectively. As noted earlier, these three protein domains had been independently identified by mass spectrometry. The applicants note that minor variations of the DNA sequence would not alter substantially the basic characteristics of the peptide that the DNA encodes. Example 7 Over-Expression of Recombinant ALP There are several commercial kits that can be used for the over-expression of the allergenic latex protein. In this example, the pMAL-c2 protein fusion and purification system (New England Biolabs, USA) is used to overexpress recombinant protein from its cloned cDNA. The procedures used for the induction of fusion protein overproduction, affinity chromatography purification, cleavage of fusion protein by factor Xa protease, and purification of the target protein by hydroxyapatite chromatography are according to the vendor's instructions. In this example, isopropyl thiogalactoside (IPTG) is used as an inducer for the expression system. The ALP cDNA is subcloned into the vector pMAL-c2 in the same translational reading frame as the malE gene of the vector. The bacterial cells are grown overnight at 37° C. on an LB indicator plate containing 100 μg/ml ampicillin, 10 μmol isopropyl thiogalactoside (IPTG) and 10 μg/ml Xgal. White colonies are picked and screened for the presence of the MBP fusion plasmid by miniprep assay. A positive clone is then taken for the overproduction of the REF protein. IPTG-induced E. coli cells are disrupted by a freeze (−20° C.)/thaw cycle (ambient temperature) and sonicating (Vibra Cell, Sonics & Materials Inc., USA) in ice-water bath with 15 seconds pulses for 3 minutes. The release of fusion protein eluted from the amylose column is monitored by assaying for protein. Whereas the amino acid sequence of the peptide is determined by the cDNA sequence in the expression vector, the applicants note that minor changes in the cDNA sequence would not alter substantially the basic characteristics of the recombinant protein. FIG. 6 shows the expressed recombinant protein and its binding to antibodies that had been developed against its native (natural) counterpart purified from natural rubber latex. Example 8 Use of ALP in Immunoassays Native or recombinant ALP or its molecular variant (a protein similar to ALP, but differing slightly, for example, in a few amino acids) can be used on its own, or in combination with an antibody developed against ALP or its molecular variant, in immunoassays. Molecular variants of ALP may occur naturally in latex or may exist as a result of laboratory manipulation. Such variants of ALP may differ only slightly from one another (e.g. by a few amino acids) and they have substantially similar basic functions or characteristics including allergenicity. Such immunoassays can be constructed in many different formats, but they basically rely on the immunological reaction between an antibody and its antigen. The antibody in this instance can be an antibody against ALP or its molecular variant, or human IgE. Its antigen can be native or recombinant ALP or its molecular variant, or a peptide that embodies the epitope site of ALP or its molecular variant. The immunoassay can be used for the diagnosis of for the diagnosis of allergy to ALP or allergy to latex in general. In a different format, the immunoassay can be used for the detection of ALP in latex or latex products. Example 9 Use of ALP in Immunotherapy Immunotherapy is a preventive treatment for allergic reactions that is carried out by giving gradually increasing doses of the allergen to which the person is allergic. The incremental increases of the allergen cause the immune system to become less sensitive to the substance when the substance is encountered in the future. There are several treatment protocols for immunotherapy. As an example, immunotherapy with ALP can be carried out by injecting a purified sample of ALP into the skin of the arm. An injection may be given once a week for about 30 weeks, after which injections can be administered every two weeks. Eventually, injections can be given every four weeks. The duration of therapy may be three or four years, sometimes longer. In place of native ALP, immunotherapy may also be carried out with a suitable recombinant ALP or the molecular variant of ALP (a protein similar to ALP, but differing slightly, for example, in a few amino acids), or a peptide representing a portion of ALP or its molecular variant. From the above description, one skilled in the art can easily ascertain the essential characteristics of the present invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usage and conditions.
|
A
|
A61
|
A61K
|
393
|
95
|
|||
11740417
|
US20120114060A1-20120510
|
MULTIPLE-INPUT, MULTIPLE-OUTPUT COMMUNICATION SYSTEM WITH REDUCED FEEDBACK
|
ACCEPTED
|
20120425
|
20120510
|
[]
|
H04B1500
|
["H04B1500", "H04L2503"]
|
8199840
|
20070426
|
20120612
|
375
|
267000
|
60016.0
|
FLORES
|
LEON
|
[{"inventor_name_last": "Zangi", "inventor_name_first": "Kambiz C.", "inventor_city": "Chapel Hill", "inventor_state": "NC", "inventor_country": "US"}, {"inventor_name_last": "Krasny", "inventor_name_first": "Leonid", "inventor_city": "Cary", "inventor_state": "NC", "inventor_country": "US"}]
|
In MIMO systems, two or more transmit signals are transmitted from different antenna clusters having one or more transmit antennas each. A precoding circuit weight the transmit signals transmitted from each transmit antenna using a common set of frequency independent antenna weights for all antenna clusters. The antenna weights are computed based on correlations between transmit antennas in the same antenna cluster.
|
1. A transmitter for transmitting a plurality of transmit signals, said transmitter comprising: a plurality of transmit antennas grouped into N antenna clusters, wherein each antenna cluster transmits a respective one of said transmit signals; a precoding circuit to weight the transmit signal transmitted from each transmit antenna in each antenna cluster using a common set of frequency independent antenna weights for all antenna clusters; and a feed back processor to receive antenna correlations from a receiver indicative of the correlations between transmit antennas within the same antenna cluster, and compute said common set of frequency independent antenna weights based on said antenna correlations. 2. (canceled) 3. The transmitter of claim 1 wherein said feedback processor computes said antenna weights by computing a transmit correlation matrix based on said antenna correlations, and selecting the eigen vector of said transmit correlation matrix having the largest eigen value as a common weight vector for weighting the transmit signal transmitted from each cluster. 4. The transmitter of claim 1 further comprising a channel feedback processor to receive said antenna weights from said receiver. 5. The transmitter of claim 1 wherein each antenna cluster has an equal number of transmit antennas. 6. The transmitter of claim 5 wherein the relative spacing of said transmit antennas in each antenna cluster is the same. 7. The transmitter of claim 6 wherein corresponding transmit antennas in different antenna clusters have the same antenna weights. 8. The transmitter of claim 1 wherein N equals the number of receive antennas at the receiver. 9. The transmitter of claim 1 further comprising: a multiplexer for dividing an information signal to be transmitted into N>1 substreams; and a channel coding circuit to encode and modulate each substream to create said transmit signals. 10. A method of transmitting a plurality of transmit signals comprising: grouping a plurality of transmit antennas into N antenna clusters, wherein each antenna cluster transmits a respective one of said transmit signals; weighting the transmit signal transmitted from each transmit antenna in each antenna cluster using a common set of frequency independent antenna weights for all antenna clusters; receiving antenna correlations from a receiver indicative of the correlations between transmit antennas within the same antenna cluster; and computing said common set of frequency independent antenna weights based on said antenna correlations. 11. (canceled) 12. The method of claim 10 wherein computing said antenna weights based on said antenna correlations comprises: computing a transmit correlation matrix based on said antenna correlations; and selecting the eigen vector of said transmit correlation matrix having the largest eigen value as a common weight vector for weighting the transmit signal transmitted from each cluster. 13. The method of claim 10 further comprising receiving said antenna weights from said receiver. 14. The method of claim 10 further comprising assigning the same number of transmit antennas to each antenna cluster. 15. The method of claim 14 further comprising spacing of said transmit antennas in each antenna cluster is the same. 16. The method of claim 15 further comprising assigning the same antenna weights to corresponding transmit antennas in different antenna clusters. 17. The method of claim 10 wherein N equals the number of receive antennas at the receiver. 18. The method of claim 10 further comprising: dividing an information signal into a plurality of substreams; and channel coding each substream to create said transmit signals. 19. A method of providing channel feedback in a multiple-input, multiple output communication system comprising a transmitter having a plurality of transmit antennas divided into two or more antenna clusters and a multiple antenna receiver, said method comprising: computing a single set of feedback information that is separately applicable to two or more antenna clusters; and providing the feedback information to the transmitter, wherein the feedback information comprises a set of antenna correlation indicating correlations between antennas within the same antenna cluster. 20. (canceled) 21. The method of claim 19 wherein the feedback information comprises a common set of frequency independent antenna weights for said transmit antennas for use with each antenna cluster. 22. A mobile terminal for a multiple input, multiple output communication system, said mobile terminal comprising: a plurality of receive antennas to receive two or more transmit signals transmitted from different antenna clusters at a transmitter; and a receive signal processor configured to: compute a single set of feedback information that is separately applicable to two or more antenna clusters; and provide the feedback to the transmitter, wherein the feedback information comprises a set antenna correlations indicating correlations between antennas within the same antenna cluster. 23. (canceled) 24. The mobile terminal of claim 22 wherein the feedback information comprises a common set of frequency independent antenna weights for the transmit antennas in each antenna cluster.
|
<SOH> BACKGROUND <EOH>The present invention relates to multiple-input, multiple output (MIMO) communication systems, and more particularly, to a MIMO system that uses knowledge of the statistics of the communication channel to prefilter the transmit signal(s). In recent years, there has been much interest in multiple input, multiple output (MIMO) systems for enhancing data rates in mobile communication systems. MIMO systems employ multiple antennas at the transmitter and receiver to transmit and receive information. The receiver can exploit the spatial dimensions of the signal at the receiver to achieve higher spectral efficiency and higher data rates without increasing bandwidth. The best performance in a MIMO system is obtained when the channel response is known to the transmitter. In this case, the transmitter can use knowledge of the channel response to compute antenna weights for each antenna so as to compensate for the channel conditions between the transmitter and the receiver. The amount of channel feedback from the receiver in such systems increases with the number of antennas at the transmitter and the receiver. The channel feedback from the receiver to the transmitter consumes valuable reverse link resources. Therefore, it is desirable to reduce the amount of feedback required to be sent on the reverse link while maintaining good performance on the forward link.
|
<SOH> SUMMARY <EOH>The present invention relates to a MIMO system that reduces the amount of channel feedback required to prefilter the transmit signals while maintaining good performance. The transmit antennas at the transmitter are grouped into clusters. There is a one-to-one correspondence between antenna clusters at the transmitter and receive antennas at the receiver. A different transmit signal is transmitted by each antenna cluster. Each transmit antenna in a given antenna cluster transmits a weighted version of the same transmit signal. A common set of frequency independent antenna weights are used for all antenna clusters. Thus, the antenna weights for the first transmit antenna in the first cluster is the same as the antenna weights for the first transmit antenna in the second, third fourth, etc, antenna cluster. By using the same set of antenna weights for all antenna clusters, the amount of channel feedback required to prefilter the transit signal is significantly reduced.
|
BACKGROUND The present invention relates to multiple-input, multiple output (MIMO) communication systems, and more particularly, to a MIMO system that uses knowledge of the statistics of the communication channel to prefilter the transmit signal(s). In recent years, there has been much interest in multiple input, multiple output (MIMO) systems for enhancing data rates in mobile communication systems. MIMO systems employ multiple antennas at the transmitter and receiver to transmit and receive information. The receiver can exploit the spatial dimensions of the signal at the receiver to achieve higher spectral efficiency and higher data rates without increasing bandwidth. The best performance in a MIMO system is obtained when the channel response is known to the transmitter. In this case, the transmitter can use knowledge of the channel response to compute antenna weights for each antenna so as to compensate for the channel conditions between the transmitter and the receiver. The amount of channel feedback from the receiver in such systems increases with the number of antennas at the transmitter and the receiver. The channel feedback from the receiver to the transmitter consumes valuable reverse link resources. Therefore, it is desirable to reduce the amount of feedback required to be sent on the reverse link while maintaining good performance on the forward link. SUMMARY The present invention relates to a MIMO system that reduces the amount of channel feedback required to prefilter the transmit signals while maintaining good performance. The transmit antennas at the transmitter are grouped into clusters. There is a one-to-one correspondence between antenna clusters at the transmitter and receive antennas at the receiver. A different transmit signal is transmitted by each antenna cluster. Each transmit antenna in a given antenna cluster transmits a weighted version of the same transmit signal. A common set of frequency independent antenna weights are used for all antenna clusters. Thus, the antenna weights for the first transmit antenna in the first cluster is the same as the antenna weights for the first transmit antenna in the second, third fourth, etc, antenna cluster. By using the same set of antenna weights for all antenna clusters, the amount of channel feedback required to prefilter the transit signal is significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a multiple input, multiple output (MIMO) communication system. FIG. 2 illustrates a clustered antenna geometry for a transmitter in a MIMO system. FIG. 3 illustrates a distributed antenna geometry for a transmitter in a MIMO system. FIG. 4 is a graph illustrating the relative performance of MIMO transmitters using Per Antenna Rate Control (PARC) and Eigen Beamforming (EBF) respectively with a clustered geometry. FIG. 5 is a graph illustrating the relative performance of MIMO transmitters using PARC and EBF with a distributed geometry. FIG. 6 is a graph illustrating the relative performance of MIMO transmitters using respectively EBF with a clustered geometry and PARC with a distributed geometry. FIG. 7 illustrates a transmitter for a MIMO communication system using clustered EBF (CEBF). FIG. 8 illustrates an exemplary IFFT circuit for a MIMO transmitter. FIG. 9 illustrates an exemplary precoding circuit for a MIMO transmitter. FIG. 10 illustrates a receiver for a MIMO communication system. FIG. 11 is a graph illustrating the relative performance of MIMO transmitters using respectively CEBF and EBF with a clustered geometry. DETAILED DESCRIPTION FIG. 1 illustrates a multiple input/multiple output (MIMO) wireless communication system 10 including a first station 12 and a second station 14. The first station 12 includes a transmitter 100 for transmitting signals to the second station 14 over a communication channel 16, while the second station includes a receiver 200 for receiving signals transmitted by the first station 12. Those skilled in the art will appreciate that the first station 12 and second station 14 may each include both a transmitter 100 and receiver 200 for bi-directional communications. In one exemplary embodiment, the first station 12 is a base station in a wireless communication network, and the second station 14 is mobile station. The present invention is particularly useful in Orthogonal Frequency Division Multiplexing (OFDM) systems. An information signal I(n) in the form of a binary data stream is input to the transmitter 100 at the first station 12. The transmitter includes a controller 102 to control the overall operation of the transmitter 100 and a transmit signal processing circuit 104. The transmit signal processing circuit 104 performs error coding, maps the input bits to complex modulation symbols, and generates transmit signals for each transmit antenna 150. After upward frequency conversion, filtering, and amplification, transmitter 100 transmits the transmit signals from respective transmit antennas 150 through the communication channel 16 to the second station 14. The receiver 200 at the second station 14 demodulates and decodes the signals received at each antenna 250. Receiver 200 includes a controller 202 to control operation of the receiver 200 and a receive signal processing circuit 204. The receive signal processing circuit 204 demodulates and decodes the signal transmitted from the first station 12. The output signal from the receiver 200 comprises an estimate Î(n) of the original information signal. In the absence of errors, the estimate Î(n) will be the same as the original information signal input I(n) at the transmitter 100. Because multiple data streams are transmitted in parallel from different antennas 150, there is a linear increase in throughput with every pair of antennas 150, 250 added to the system without an increase in the bandwidth requirement. MIMO systems have been the subject of extensive research activity worldwide for use in wireless communication networks because of their potential to achieve high spectral efficiencies, and therefore high data rates. A MIMO system with M transmit antennas and N receive antennas is typically described by the following matrix representation: y(f)=G(f)x(f)+z(f), Eq. (1) where y(f) is the N×1 received signal vector, G(f) is the N×M MIMO channel response, z(f) is the independent and identically distributed (i.i.d.) AWGN at the receiver with individual variance of 2, and x(f) is the M×1 transmitted signal vector with a certain power constraint. In general, the best performance in a MIMO system is achieved when the channel response is known to the transmitter 100 so that the transmit signals can be weighted accordingly by the transmitter 100 prior to transmission. One MIMO approach that is attracting significant attention is Per Antenna Rate Control (PARC). In PARC systems, information to be transmitted is divided into multiple streams. Each stream is independently encoded and modulated, and then transmitted from a respective transmit antenna 150. The coding rates depend on the signal to interference plus noise ratio (SINR). In conventional PARC systems, the number of transmit antennas 150 is fixed and all transmit antennas 150 are used all the time to transmit data to mobile stations. Another MIMO approach attracting attention is known as the Eigen Beamforming (EBF). In EBF systems, the transmit signals transmitted by each transmit antenna 150 are pre-filtered prior to transmission. For MIMO systems using Eigen Beamforming (EBF), a precoding circuit applies an M×N coding matrix and outputs N transmit signals; one for each receive antenna 250. The rows of the precoding matrix are the N eigen vectors, corresponding to the largest eigen values of the matrix: H _ = 1 N f ∑ k = 1 N f G H ( f k ) G ( f k ) , Eq . ( 2 ) where Nf is the number of averaging sub-carriers. In the EBF approach, M×N complex elements of the precoding matrix must be fed back from the receiver 200 to the transmitter 100 on the reverse link. For purposes of this application, the term reverse link is used to refer to the channel used to feedback information from the receiver to the transmitter. The reverse link channel may be an uplink channel (mobile terminal to base station) or a downlink channel (base station to mobile terminal). Different antenna geometries can be used with either the PARC approach or the EBF approach. FIGS. 2 and 3 illustrate two exemplary antenna geometries for a MIMO transmitter 100. The antenna geometry shown in FIG. 2, referred to herein as the clustered geometry, groups the transmit antennas 150 into two or more antenna clusters 152. The antenna clusters 152 are separated by a large distance (e.g., 10λ) so that the antennas 150 in different antenna clusters 152 can be considered to be essentially independent from each other. The transmit antennas 150 within each antenna cluster 152 are closely spaced (e.g., 0.5λ) so that the transmit antennas 150 within the same antenna cluster 152 are highly correlated. The geometry shown in FIG. 3, referred to as the distributed geometry, places the transmit antennas 150 far apart (e.g., 10λ) so that all of the transmit antennas 150 can be considered mutually independent. FIGS. 4 and 5 illustrate the relative performance of the PARC and EBF approaches for the clustered and the distributed antenna geometries. FIG. 4 shows the average data rate as a function of the average SNR for the PARC approach. FIG. 4 shows that the PARC approach is best when the distributed geometry (Geometry 2) is used. FIG. 5 shows the average data rate as a function of the average SNR for the EBF approach. FIG. 5 shows that the EBF approach is best when the clustered geometry (Geometry 1) is used. FIG. 6 compares the performance of the PARC approach using a distributed geometry with the EBF approach using the clustered geometry. FIG. 6 shows that the EBF approach with the clustered geometry is best when the SNR is below 12 dB. In a typical mobile communication system with a 1/1 reuse factor, the overwhelming majority of users (e.g. approximately 90%) will have an SNR less than 12 dB. Thus, the EBF approach with a clustered geometry will be the best approach for the majority of users. The EBF approach requires that M×N complex coefficients be fed back from the receiver 200 to the transmitter 100 to compute the prefilter matrix. FIG. 7 illustrates a transmit signal processing circuit 104 for a transmitter 100 using a technique referred to herein as Clustered Eigen Beamforming (CEBF). This technique allows a reduction in the amount of channel feedback required while achieving performance levels that are very close to that obtained using the EBF approach with a clustered geometry. In this approach, the transmit antennas 150 are grouped into N antenna clusters 152, where N equals the number of receive antennas 250 at the receiver 200. In one embodiment, there are M/N transmit antennas 150 in each antenna cluster 152. For example, consider a MIMO system with six transmit antennas 150 and two receive antennas 250. The six transmit antennas 150 may be divided into two antenna clusters 152 with three transmit antennas 150 each. The transmit antennas 150 in each antenna cluster 152 are closely spaced (e.g., 0.5λ) so that the transmit antennas 150 in the same antenna cluster 152 are highly correlated. The antenna clusters 152 are spaced far apart (e.g., 10λ) so that the transmit antennas 150 in different antenna clusters 152 may be considered independent. The transmit signal processing circuit 104 for the CEBF approach comprises a demultiplexer 106, a channel coding circuit 107, a precoding circuit 120, a plurality of transmitter front end circuits 122, and a feedback processor 124. An information bitstream I(n) is divided by demultiplxer 1067 into N substreams {I1(n), . . . IN(n)}, where equals the number of antenna clusters 152. Each substream Ii(n) for i=1, . . . N is input to a corresponding channel coding circuit 107 including an encoder 108, a modulator 110, an Inverse Fast Fourier Transform (IFFT) circuit 112. Encoder 108 comprises an error correction encoder, such as a Turbo encoder or convolutional encoder. The modulator 110 may comprise, for example a QPSK or QAM modulator. The modulation symbol streams {s1(n), . . . sN(n)} output by the respective modulators 110 are input to an IFFT circuit 112 (FIG. 8). The IFFT circuit 112 includes a serial-to-parallel (S/P) converter 114 to divide the stream of modulation symbols si(n) from the modulator 110 into Nc substreams, where Nc equals the number of subcarriers, an IFFT filter 116 to apply an Inverse Fast Fourier transform as is known in the art, and a parallel-to-serial (P/S) converter 118 to generate a transmit signal {tilde over (s)}i(n). The transmit signals {{tilde over (s)}1(n), . . . {tilde over (s)}N(n)} output from each channel coding circuit 107 is input to the precoding circuit 120. The precoding circuit 120 weights the transmit signals using antenna weights denoted by the weight vector W of size M N × 1 provided by the feedback processor 124. It should be noted that a common set of frequency independent antenna weights is used for each antenna cluster 152. The generation of the weighted transmit signals fed to each transmit antenna 150 from the transmit signals {{tilde over (s)}1(n), . . . {tilde over (s)}N(n)} is described below. Referring to FIG. 9, the precoding circuit 120 takes {{tilde over (s)}1(n), . . . {tilde over (s)}N(n)} as its input and generates weighted transmit signals {x1(n), . . . xM(n)} at its output, where xk(n) represents the signal fed to the front end 122 of the kth transmit antenna 150. The transmit antennas 150 are grouped into N antenna clusters 152, where each antenna cluster 152 comprises M N transmit antennas 150. As shown in FIG. 9, {tilde over (s)}i(n) is fed to the transmit antennas 150 in the ith antenna cluster 152. For each transmit antenna 150 in the antenna cluster 152, the transmit signal {tilde over (s)}i(n) is weighted by a corresponding antenna weight wj, where j denotes the jth transmit antenna 152 in an antenna cluster 152. Thus, the first transmit antenna 150 in the ith antenna cluster 152 transmits {tilde over (s)}i(n)·w1, the second transmit antenna 152 in the ith antenna cluster 152 transmits {tilde over (s)}i(n)·w2, etc. More generally, the jth transmit antenna in the ith antenna cluster 152 transmits {tilde over (s)}i(n)·wj. In one exemplary embodiment, the same set of frequency independent antenna weights { w j } j = 1 M N are used by each antenna cluster 152. The common set of antenna weights { w j } j = 1 M N is represented by the weight vector w = [ w 1 , … w M N ] T . The antenna weights may be computed as follows. Let Gi(f) represent the N × M N channel response matrix for the channel between the transmit antennas in the ith cluster 152 and the N receive antennas at the receiver. The weight vector W may be computed as the eigen vector corresponding to the largest eigen value of the transmit correlation matrix D _ = 1 N f 1 N ∑ k = i N f ∑ i = 1 N G i T ( f k ) G i ( f k ) Eq . ( 3 ) The antenna weights may be computed by the receiver 200 and fed back to the transmitter 100 by the receiver 200 or, alternatively, computed by the feedback processor 124 based on feedback of antenna correlations from the receiver 200 as hereinafter described. It may be noted that the transmit correlation matrix D is approximately equal to the expected value of the channel correlation matrix E{GiT(f)Gi(f)} for each antenna cluster 152. It has been observed that with the clustered geometry, the correlations between transmit antennas 150 in an antenna cluster 152 will be the same for each antenna cluster 152 assuming that the antennas 150 in each antenna cluster 152 have the same relative spacing. Consequently, the expected value of the channel correlation matrix E{GiT(f)Gi(f)} for the antennas 150 in all antenna clusters 152 are the same. FIG. 10 illustrates the receive signal processing circuit 204 for a MIMO receiver 200 using the CEBF approach. The receiver comprises N receive antennas 250. As previously noted, the number of receive antennas 250 equals the number of antenna clusters 152 at the transmitter 100. A receiver front end circuit 206 downconverts the received signals {r1(t), . . . rN(t)} at each receive antenna 250 to baseband frequency and converts the baseband signals into digital form for processing by the receive signal processing circuit 204. The digitized received signals {r1(n), . . . rN(n)} are input to a combiner 208 that combines the received signals {r1(n), . . . rN(n)} and outputs estimates {{circumflex over (x)}1(n), . . . {circumflex over (x)}N(n)} of the transmitted signal {x1(n), . . . xN(n)}. The estimates {{circumflex over (x)}1(n), . . . {circumflex over (x)}N(n)} are input to corresponding IFFT circuits 210 which apply a Fast Fourier transform and output estimates {ŝ1(n), . . . ŝN(n)} of the modulation symbol streams {s1(n), . . . sN(n)}. The symbol stream estimates {ŝ1(n), . . . ŝN(n)} are demodulated by corresponding demodulators 212 using channel estimates provided by a channel estimator 218. The channel estimator 218 computes the channel estimates based on the received signal as known in the art. Demodulators 212 output estimates {ĉ1(n), . . . ĉN(n)} of the coded bit streams. These estimates are input to a parallel to serial converter 214 and converted into a parallel bitstream, which is an estimate ĉ(n) of the coded bitstream c(n) input at the transmitter 100. A decoder 216 decodes the estimate ĉ(n) to produce an estimate Î(n) of the original information signal I(n). The channel estimates computed by the channel estimator 218 are also input to a feedback processor 220 to generate channel feedback for use by the transmitter 100. The channel feedback processor 220 may compute antenna weights as described above, and transmit the antenna weights to the transmitter 100. This approach requires the receiver 200 to feed back M×N antenna weights. Instead of computing antenna weights, the feedback processor 220 may instead compute the transmit correlations that comprise the transmit correlation matrix D. In this case, the feedback processor 124 at the transmitter 100 can compute the antenna weights from the transmit correlations. Those skilled in the art may recognize that it is not necessary to feed back the entire transmit correlation matrix D. As previously noted, the transmit correlations in the transmit correlation matrix D represent the correlations between the transmit antennas 150 in a given antenna cluster 152, which is the same for all antenna clusters 152. It has been observed that the transmit correlation matrix D is a Toeplitz Hermitian matrix. Therefore, the receiver 200 only needs to feed back the transmit correlations corresponding to a single row in the transmit correlation matrix D. With a single row of the transmit correlations, the transmitter 100 can reconstruct the transmit correlation matrix D and compute the combining weights. FIG. 11 is a graph comparing the performance of the CEBF transmitter shown in FIG. 7 with a more conventional EBF transmitter using a clustered antenna geometry. As shown in FIG. 11, the CEBF approach achieves a performance level very close to the EBF approach using different antenna weights for each antenna cluster 152. Given that the CEBF approach significantly reduces the amount of channel feedback required, the CEBF approach provides an attractive alternative. A transmitter 100 using the CEBF approach requires the computation of M/N antenna weights. In contrast, the more conventional EBF approach described above requires M×N antenna weights to be computed. Thus, the present invention reduces the number of antenna weights needed for operation by a factor of N2 as compared to conventional practice. The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
|
H
|
H04
|
H04B
|
15
|
00
|
|||
11863125
|
US20090084657A1-20090402
|
MODULAR WIRELESS CONVEYOR INTERCONNECTION METHOD AND SYSTEM
|
ACCEPTED
|
20090318
|
20090402
|
[]
|
B65G4310
|
["B65G4310", "B65G4100", "G06F1516"]
|
7954621
|
20070927
|
20110607
|
198
|
575000
|
60100.0
|
DEUBLE
|
MARK
|
[{"inventor_name_last": "Brandt", "inventor_name_first": "David Dale", "inventor_city": "New Berlin", "inventor_state": "WI", "inventor_country": "US"}, {"inventor_name_last": "Wielebski", "inventor_name_first": "Wayne H.", "inventor_city": "New Berlin", "inventor_state": "WI", "inventor_country": "US"}]
|
A modular conveyor system is disclosed in which components of each conveyor module is designed for wireless mesh communication. The communications may be within a module or between modules. Certain of the components may be powered by battery, such that the components may be completely wireless. The network may be entirely self-configuring such that the modules may be assembled and the network established in a straightforward manner.
|
1. A modular conveyor system comprising: a plurality of conveyor modules; and a plurality of wireless mesh communication points disposed on the plurality of conveyor modules and configured to communicate wirelessly over a mesh network. 2. The modular conveyor system of claim 1, wherein the plurality of wireless mesh communication points are configured to automatically form an ad hoc wireless mesh network. 3. The modular conveyor system of claim 1, further comprising a supervisory system configured to communicate wirelessly with the plurality of conveyor modules over a mesh network. 4. The modular conveyor system of claim 1, further comprising a pushbutton station comprising one of the plurality of wireless mesh communication points. 5. The modular conveyor system of claim 4, wherein the pushbutton station further comprises a battery and is configured to draw power exclusively from the battery. 6. The modular conveyor system of claim 1, further comprising a process indicator light comprising one of the plurality of wireless mesh communication points. 7. The modular conveyor system of claim 6, wherein the indicator light further comprises a battery and is configured to draw power exclusively from the battery. 8. A conveyor module for a modular conveyor system comprising: a conveyor; at least one motor coupled to the conveyor and configured to move the conveyor; at least one motor controller configured to drive the at least one motor; and a mote configured to enable the least one motor controller to communicate with another device over a wireless mesh network. 9. The conveyor module of claim 8, further comprising a wireless sensor configured to communicate with another device over the wireless mesh network. 10. The conveyor module of claim 8, wherein the mote is configured to enable the at least one motor controller to communicate over the wireless mesh network with a handheld control device. 11. The conveyor module of claim 8, further comprising a pushbutton station configured to communicate with another device over the wireless mesh network. 12. The conveyor module of claim 11, wherein the pushbutton station comprises a battery and is configured to rely on the battery for power. 13. The conveyor module of claim 8, wherein the mote is configured to enable the at least one motor controller to communicate over the wireless mesh network with a motor controller of an adjacent conveyor module. 14. The conveyor module of claim 13, wherein the mote is configured to communicate via an alternate path over the wireless mesh network for communication with the motor controller of the adjacent conveyor module when a direct path to the motor controller of the adjacent conveyor module is obstructed. 15. A method of configuring a modular conveyor system comprising: sensing actuation of a mote disposed on or associated with a conveyor module, wherein the mote is configured to communicate over a wireless mesh network; detecting a signal over the wireless mesh network from an upline conveyor module; receiving a signal from the upline conveyor module announcing the presence of the upline conveyor module; sending a signal over the wireless mesh network to the upline conveyor module announcing the presence of the conveyor module; linking the conveyor modules via the wireless mesh network to operate jointly. 16. The method of claim 15, further comprising detecting a signal over the wireless mesh network from a downline conveyor module, receiving a signal from the downline conveyor module announcing the presence of the downline conveyor module, sending a signal over the wireless mesh network to the downline conveyor module announcing the presence of the conveyor module, and linking the downline conveyor module and the other conveyor modules via the wireless mesh network to operate jointly. 17. A method of configuring a modular conveyor system comprising: establishing a wireless mesh network across components of a modular conveyor system; connecting a conveyor module to a computer system over the wireless mesh network; and downloading association information from the computer system to the conveyor module to associate the conveyor module to the modular conveyor system. 18. The method of claim 17, wherein connecting the conveyor module to the computer system over the wireless mesh network further comprises sending a serial number of the conveyor module to the computer system. 19. The method of claim 17, wherein establishing a wireless mesh network further comprises locating each mesh node to determine a location of the components of the modular conveyor system. 20. The method of claim 19, wherein establishing a wireless mesh network further comprises sending the location of the components of the modular conveyor system to the computer system. 21. The method of claim 17, wherein the computer system is preprogrammed with a location of each of the components of the modular conveyor system and is configured to determine association information for the conveyor module based on the location of components of the modular conveyor system. 22. The method of claim 21, wherein the location of each of the components of the modular conveyor system is set on a map in configuration software. 23. A modular conveyor system comprising: a plurality of conveyor modules; and a plurality of wireless mesh nodes disposed on the plurality of conveyor modules and configured to enable the plurality of conveyor modules to communicate wirelessly over a mesh network. 24. The modular conveyor system of claim 23, wherein each of the plurality of conveyor modules is configured to self-associate to the modular conveyor system by associating with an upline conveyor module over the wireless mesh network and associating with a downline conveyor module over the wireless mesh network. 25. The modular conveyor system of claim 23, wherein each of the plurality of conveyor modules is configured to associate to the modular conveyor system by communicating with a computer system over the mesh network and downloading association data from the computer system based on a location of each of the plurality of conveyor modules in the modular conveyor system.
|
<SOH> BACKGROUND <EOH>The invention relates generally to communication across components in a conveyor system. More particularly, the invention relates to a technique for wireless mesh communication interconnecting components of a modular conveyor system. Automation in manufacturing, shipping, and other applications often involves moving materials from one specialized work cell to another or to a final destination. Fixed material handling systems, such as conveyors, may route materials between cells. To facilitate the deployment of a fixed conveyor system, a system designer may purchase a conveyor system in multiple parts, known as “modules,” to be assembled on site. With the proper application of modules, a modular conveyor system can sort, manipulate, measure, and move materials between locations. Each module of a modular conveyor system generally communicates with surrounding modules and a supervisory system. A module may communicate with an adjacent module to coordinate material movement to or from the adjacent module. Additionally, many material handling decisions may require a module to collect other information first from a supervisory system before executing the decision. A module may also communicate with a supervisory system to report a conveyor jam or to download a reconfiguration command. Legacy communication schemes run discrete wires or cables from each module directly to a central controller and supervisory system. More recent communication schemes seek to avoid prohibitively expensive, complicated cabling by employing module-to-module wired communication. However, such a daisy-chain strategy often leads to extended repair cycles when a fault occurs in the cabling. To avoid cabled communication in conveyor systems, wireless communication has been employed in a limited manner. As recently implemented, however, wireless communication schemes have relied either upon access point infrastructure or simple point-to-point connections for certain communications. However such solutions do not support a complete and truly modular wireless conveyor system topology, but instead support limited function including supervisory system connection, wireless operator controls, and diagnostic sensing. Moreover, if communication in a modular conveyor system were based on access point infrastructure the cost would be higher and the system would not be self-contained. If communication were based on simple point-to-point connections, the system would not be robust against communication disruptions.
|
<SOH> BRIEF DESCRIPTION <EOH>The invention includes a system and method for interconnecting a modular conveyor system using wireless mesh communication. In accordance with an aspect of the invention, a modular conveyor system may comprise a plurality of conveyor modules with wireless mesh communication points configured to communicate wirelessly over a mesh network. The plurality of wireless mesh communication points may automatically form an ad hoc wireless mesh network to route communication from component to component. Additionally, the modular conveyor system may comprise a supervisory system, battery-powered pushbutton stations, indicator lights, and/or a handheld conveyor system control device, each of which may be configured to communicate wirelessly with one another over the mesh network. In accordance with another aspect of the invention, a conveyor module for a modular conveyor system may comprise a conveyor, a motor to move the conveyor, a motor controller to drive the motor, and a mote configured to enable the motor to communicate with another device over a wireless mesh network. The motor controller may be configured to communicate with a motor controller of an adjacent conveyor module. Additionally, the mote may be configured to communicate via an alternate path over the wireless mesh network when a direct path to the motor controller of the adjacent conveyor module is obstructed. As used herein, a “mote” is intended to mean a low power wireless mesh communication device that may be separate from or integrated into a wireless networkable component of a conveyor system or module. Moreover, a technique for associating a conveyor module to a modular conveyor system is included. In accordance with another aspect of the invention, when a button is pressed on a pushbutton station disposed on or associated with a conveyor module, a conveyor module listens for a signal over the wireless mesh network from an upline conveyor module. The conveyor module then receives a signal from the upline conveyor module announcing the presence of the upline conveyor module, and sends a signal over the wireless mesh network to the upline conveyor module announcing the presence of the conveyor module. The conveyor module may additionally listen for a signal over the wireless mesh network from a downline conveyor module, receive a signal from the downline conveyor module announcing the presence of the downline conveyor module, and thereafter send a signal over the wireless mesh network to the downline conveyor module announcing the presence of the conveyor module. Furthermore, another technique for associating a conveyor module to a modular conveyor system is also included. In accordance with another aspect of the invention, a wireless mesh network is established across components of a modular conveyor system. Once a conveyor module is connected to a computer system over the wireless mesh network, the conveyor module downloads association information from the computer system to associate the conveyor module to the modular conveyor system. Additionally or alternatively, the conveyor module may send the computer system a serial number of the conveyor module, or may determine its location relative to other wireless mesh components and send the relative location information to the computer system before downloading association information.
|
BACKGROUND The invention relates generally to communication across components in a conveyor system. More particularly, the invention relates to a technique for wireless mesh communication interconnecting components of a modular conveyor system. Automation in manufacturing, shipping, and other applications often involves moving materials from one specialized work cell to another or to a final destination. Fixed material handling systems, such as conveyors, may route materials between cells. To facilitate the deployment of a fixed conveyor system, a system designer may purchase a conveyor system in multiple parts, known as “modules,” to be assembled on site. With the proper application of modules, a modular conveyor system can sort, manipulate, measure, and move materials between locations. Each module of a modular conveyor system generally communicates with surrounding modules and a supervisory system. A module may communicate with an adjacent module to coordinate material movement to or from the adjacent module. Additionally, many material handling decisions may require a module to collect other information first from a supervisory system before executing the decision. A module may also communicate with a supervisory system to report a conveyor jam or to download a reconfiguration command. Legacy communication schemes run discrete wires or cables from each module directly to a central controller and supervisory system. More recent communication schemes seek to avoid prohibitively expensive, complicated cabling by employing module-to-module wired communication. However, such a daisy-chain strategy often leads to extended repair cycles when a fault occurs in the cabling. To avoid cabled communication in conveyor systems, wireless communication has been employed in a limited manner. As recently implemented, however, wireless communication schemes have relied either upon access point infrastructure or simple point-to-point connections for certain communications. However such solutions do not support a complete and truly modular wireless conveyor system topology, but instead support limited function including supervisory system connection, wireless operator controls, and diagnostic sensing. Moreover, if communication in a modular conveyor system were based on access point infrastructure the cost would be higher and the system would not be self-contained. If communication were based on simple point-to-point connections, the system would not be robust against communication disruptions. BRIEF DESCRIPTION The invention includes a system and method for interconnecting a modular conveyor system using wireless mesh communication. In accordance with an aspect of the invention, a modular conveyor system may comprise a plurality of conveyor modules with wireless mesh communication points configured to communicate wirelessly over a mesh network. The plurality of wireless mesh communication points may automatically form an ad hoc wireless mesh network to route communication from component to component. Additionally, the modular conveyor system may comprise a supervisory system, battery-powered pushbutton stations, indicator lights, and/or a handheld conveyor system control device, each of which may be configured to communicate wirelessly with one another over the mesh network. In accordance with another aspect of the invention, a conveyor module for a modular conveyor system may comprise a conveyor, a motor to move the conveyor, a motor controller to drive the motor, and a mote configured to enable the motor to communicate with another device over a wireless mesh network. The motor controller may be configured to communicate with a motor controller of an adjacent conveyor module. Additionally, the mote may be configured to communicate via an alternate path over the wireless mesh network when a direct path to the motor controller of the adjacent conveyor module is obstructed. As used herein, a “mote” is intended to mean a low power wireless mesh communication device that may be separate from or integrated into a wireless networkable component of a conveyor system or module. Moreover, a technique for associating a conveyor module to a modular conveyor system is included. In accordance with another aspect of the invention, when a button is pressed on a pushbutton station disposed on or associated with a conveyor module, a conveyor module listens for a signal over the wireless mesh network from an upline conveyor module. The conveyor module then receives a signal from the upline conveyor module announcing the presence of the upline conveyor module, and sends a signal over the wireless mesh network to the upline conveyor module announcing the presence of the conveyor module. The conveyor module may additionally listen for a signal over the wireless mesh network from a downline conveyor module, receive a signal from the downline conveyor module announcing the presence of the downline conveyor module, and thereafter send a signal over the wireless mesh network to the downline conveyor module announcing the presence of the conveyor module. Furthermore, another technique for associating a conveyor module to a modular conveyor system is also included. In accordance with another aspect of the invention, a wireless mesh network is established across components of a modular conveyor system. Once a conveyor module is connected to a computer system over the wireless mesh network, the conveyor module downloads association information from the computer system to associate the conveyor module to the modular conveyor system. Additionally or alternatively, the conveyor module may send the computer system a serial number of the conveyor module, or may determine its location relative to other wireless mesh components and send the relative location information to the computer system before downloading association information. DRAWINGS These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: FIG. 1 illustrates an exemplary modular conveyor system employing a wireless mesh communication scheme in accordance with an aspect of the invention; FIG. 2 illustrates communication among wireless mesh communication points of the exemplary conveyor system of FIG. 1; FIG. 3 represents an exemplary modular conveyor system module employing a wireless mesh communication scheme in accordance with an aspect of the invention; FIG. 4 is a diagrammatical representation of an exemplary pushbutton station for a modular conveyor system communicating wirelessly with a motor controller in accordance with an aspect of the invention; FIG. 5 is a diagrammatical representation of an exemplary motor controller for a modular conveyor system module communicating wirelessly with another motor controller in accordance with an aspect of the invention; FIG. 6 is a diagrammatical representation of an exemplary supervisory system for a modular conveyor system communicating wirelessly with a motor controller in accordance with an aspect of the invention; FIG. 7 illustrates a message routed across a modular conveyor system using supervisory mesh routing in accordance with an aspect of the invention; and FIG. 8 illustrates alternate mesh routing paths for sending a message when a direct path is obstructed in accordance with an aspect of the invention. DETAILED DESCRIPTION Referring to FIG. 1, an exemplary modular conveyor system 10 comprises a plurality of conveyor modules configured to communicate with various components over a wireless mesh network. Although four representative conveyor modules 12, 14, 16, and 18 appear in FIG. 1, modular conveyor system 10 may comprise any number of interconnected conveyor modules. Conveyor modules 12 and 16 move materials 20 and 22 forward toward hand off points 24, at which point materials 20 will be handed off to either conveyor module 14 or 18, as appropriate, and materials 22 will be handed off to conveyor module 18. Materials 20 and 22 are moved across a conveyor on each conveyor module by a drive roller 26, which rotates in response to torque signals from a motor controller 28 disposed on each conveyor module. When materials 20 or 22 cross a hand off point 24 onto conveyor module 14 or 18, an entry sensor 30 may sense the presence of the materials, which may thereafter signal to the prior conveyor module 12 or 16 that materials 20 or 22 have been handed off. Similarly, when materials 20 or 22 approach a hand off point 24 from conveyor module 12 or 16, each may pass an exit sensor 32. The exit sensor 32 may signal to the proximate adjacent conveyor module 14 or 18 that materials 20 or 22 is about to be handed off. Entry sensor 30 and exit sensor 32 may directly communicate over a wireless mesh network to a motor controller 28 of a different conveyor module. However, entry sensor 30 and exit sensor 32 may instead communicate over communication wires to a main motor controller 28 on the same conveyor module, which may thereafter communicate over a wireless mesh network to a motor controller 28 of a different conveyor module. Conveyor module 12 represents a diverter module, which may divert materials to either conveyor module 14 or 18. Diverter sensor 34 senses information from materials 20, such as a barcode or RFID data, as materials 20 move across conveyor module 12. Communicating wirelessly over a mesh network or over communication wires to the motor controller 28 of module 12, diverter sensor provides the information about materials 20 so that a decision whether to divert materials 20 may be made. To facilitate human operation of the system, modular conveyor system 10 comprises indicator lights 36 and pushbutton stations 38. Indicator lights 36 may be associated with or attached to a conveyor module, but may also be located elsewhere in the modular conveyor system. If attached to a wireless conveyor module, indicator lights 36 may communicate with other devices over a wireless mesh network directly or via wired communication to a motor controller 28 with access to the wireless mesh network. After receiving a signal over the network regarding the status of a particular conveyor module or the modular conveyor system 10 generally, indicator lights 36 electrify a bulb of particular color, which signals to human operators the status of operation. Pushbutton stations 38 may comprise one or more pushbuttons 40. When a pushbutton 40 is pressed, a pushbutton station 38 may issue a signal across a wireless mesh network comprising, for example, a command or instruction to stop or to resume operation. A given pushbutton station 38 may also be associated with or attached to a particular conveyor module, and may be configured to initiate a self-configuration operation for the associated conveyor module by associating with upline and downline conveyor modules. Reviewing again conveyor module 12, after diverter sensor 34 obtains information from materials 20 and transmits the data to another device to make a decision whether to divert, a decision signal is sent from the other device to diverter 42. Often, the decision whether to divert requires information external to the conveyor module, and therefore a supervisory system often decides, sending a decision signal after consulting a database. However, a local device, such as motor controller 28 of conveyor module 12 or the diverter sensor 34 itself may comprise sufficient information and circuitry to make the decision to divert. When diverter 42 receives the decision signal, an actuator 44 may move the diverter arm depending on the position of the diverter arm as observed by position sensor 46. Human operators may track operational status with monitoring station 48. Receiving data from the various components of modular conveyor system 10 over a wireless mesh network, monitoring station 48 alerts human operators to conveyor system status and forwards the data to additional supervisory systems over network 50. Network 50 may represent a local or wide area network, or a virtual private network across the Internet, and may be wired or wireless. Network 50 interconnects monitoring station 48 with a remote control and monitoring system 52. An operator interface 54 connects to remote control and monitoring system 52 and provides remote operation capability to operators that may be located far from the conveyor system floor. Remote control and monitoring system 52 connects to wide area network 56, which may comprise, for example, a company-wide network or the Internet. To communicate with monitoring station 48 and each other, components of modular conveyor system 10 may comprise mesh communication circuitry 58. The mesh communication circuitry 58 disposed on components of modular conveyor system 10 allow for peer-to-peer communication as well as forming the backbone of an ad hoc wireless mesh network. Although mesh communication circuitry 58 may implement an 802.11x protocol, implementing an 802.15.4 protocol may provide superior power management, despite lower data transmission rates. It should be recognized that wireless meshing in the present context is, however, independent of any particular standard. FIG. 2 illustrates an exemplary wireless mesh network formed by ad hoc wireless interconnections of wireless mesh circuitry 58. First conveyor communication zone 60 represents an exemplary wireless mesh network which may form among components disposed on conveyor 12 (depicted in FIG. 1). Similarly, second conveyor communication zone 62, third conveyor communication zone 64, and fourth conveyor communication zone 66 represent exemplary wireless mesh networks which may form among components disposed on conveyors 14, 16, and 18. The wireless mesh circuitry 58 of each component forms communication links 68 to the wireless mesh circuitry 58 of adjacent components, composing overall conveyor system mesh 70. A component may communicate with an adjacent component directly over an immediate adjacent communication link 68. Additionally, however, a component may engage in peer-to-peer communication with any other component of the conveyor system 10 by sending a signal over an adjacent communication link 68 for routing through the wireless mesh circuitry 58 of an adjacent component. The wireless mesh circuitry 58 of the adjacent component then routes the communication signal forward over an adjacent communication link 68 to another adjacent component, which subsequently routes the communication signal forward in the same way, until the destination component receives the signal. Accordingly, any component may communicate with any other component of the modular conveyor system 10. Moreover, certain components may also perform only the function of routing, such as for mesh connectivity or redundancy. Referring now to FIG. 3, an exemplary conveyor module with wireless mesh communication capability comprises a motor controller 28 with wireless mesh circuitry 58 (represented by an antenna symbol in FIG. 3). A conveyor belt 72 moves across rollers 74, held in place by support structure 76. Motor controller 28 drives a motor 78 which pulls drive link 80, causing drive roller 26 to rotate and move conveyor belt 72. Wireless start button 82 and stop button 84 may be located on a pushbutton station 38. Because start button 82 and stop button 84 each draw power from a battery 86, the pushbutton station 38 may be located remotely from the conveyor module or on the conveyor module by attachment, for example, to support structure 76. It should be noted that, as an alternative to the arrangement shown in FIG. 3, certain conveyors may integrate rollers, motors, drives and so forth in a single unit, and may provide multiple integrated units in certain conveyor modules, each with a wireless interface. Both exit sensor 32 and motor 78, being permanently attached to the conveyor module, may communicate with the motor controller 28 via a wired communication link 88. By contrast, start button 82 and stop button 84 send control communication 90 wirelessly to motor controller 28 via wireless mesh circuitry 58. Other embodiments, however, may include an alternative wired communication link between the start button 82 and stop button 84 and the motor controller 28. The motes of each of the components may have push buttons or other similar input means for sending signals for configuration of the network or the devices may be powered up to initiate such signals to begin association with other devices. Sequencing of such initiation may be performed to enable linking of the devices in the desired conveyor application configuration as well as configuring the network for optimal wireless mesh communication between them. Continuing to refer to FIG. 3, motor controller 28 may conduct a conveyor module association sequence by using wireless mesh circuitry 58 to listen for an upline communication signal 92 from an adjacent upline conveyor module that announces the presence of the upline module. Motor controller 28 may subsequently send a wireless upline communication signal 92 back to the upline conveyor module, announcing the presence of the conveyor module to the upline conveyor module. Accordingly, the conveyor module and the upline conveyor module may exchange association information to become associated with each other. Similarly, motor controller 28 may continue the conveyor module association sequence by further associating with a downline conveyor module. Using wireless mesh circuitry 58, motor controller 28 listens for a downline communication signal 94 from an adjacent downline conveyor module that announces the presence of the downline module. Motor controller 28 may subsequently send a wireless downline communication signal 94 back to the downline conveyor module, announcing the presence of the conveyor module to the downline conveyor module. After exchanging association information, the conveyor module and the downline conveyor module may thus become associated with each other, as well. Moreover, adjacent sections, upline and downline, of the overall system may communication on a peer-to-peer basis (rather than “multi-hop”) in order to minimize the time delay in communications. Additionally or alternatively, the conveyor module may associate with the wider modular conveyor system 10 by communicating with a supervisory system, such as remote control and operating system 52, via supervisory communication 96 over a wireless mesh network. The supervisory system may subsequently provide the conveyor module with configuration data in a variety of ways. According to one embodiment, once the wireless mesh network has been established by the wireless mesh circuitry 58 of components of the modular conveyor system 10, motor controller 28 of the conveyor module may communicate with a supervisory system via supervisory communication link 96. The motor controller 28 may send identifying information, such as a serial number of the conveyor module, to the supervisory system. The supervisory system may be preprogrammed with a location of each component of the modular conveyor system, and may then send appropriate association information to motor controller 28 based on the relative location of the conveyor module to other components. Preprogrammed component locations may be stored, for example, in a computer aided design (CAD) map of the modular conveyor system. According to another embodiment, however, wireless mesh circuitry 58 of components of the modular conveyor system 10 may first determine the relative location of each wireless node formed by each component. After determining its relative location, each component may connect to the supervisory system via supervisory communication link 96 to transmit the location data to the supervisory system. When the supervisory system has obtained the relative location of each component of the modular conveyor system, the supervisory system may determine appropriate association information for each component. Motor controller 28 may subsequently download the appropriate association information from the supervisory system. Accordingly, the association sequence may be greatly simplified as compared to other common techniques. Turning to FIG. 4, exemplary conveyer module operator control configuration 98 illustrates communication from a pushbutton 40 to a motor controller 28 for controlling a conveyor module. Conveyor module control begins when pushbutton 40 is pressed by a human operator, prompting power links 100 to close a circuit on adapter board 102. Adapter board 102 consequently generates and sends a packet of switch bits based upon push button input status to a mote 104 comprising wireless mesh circuitry 58 and powered by a battery 86. The mote 104 wraps the packet of switch bits using the 802.15.4 wireless protocol and wirelessly transmits the wrapped data packet 106 to another mote 108 having similar wireless mesh circuitry 58. By communicating under the 802.15.4 wireless protocol, power consumption is largely minimized. Accordingly, mote 104 and adapter board 102 may draw power exclusively from battery 86 for an extended period of time of months or even years. It should be noted that the separate adapter boards and motes discussed in the present context may be eliminated as separate components, particularly when the motes are integrated into conveyor application components, such as push button assemblies, motor controllers, and so forth. When mote 108 receives the wrapped data packet 106 from mote 104, mote 108 unwraps and passes the packet of switch bits to adapter board 110. To render the packet of pushbutton switch bits comprehensible to the motor controller 28, adapter board 110 wraps the packet of switch bits with a modular conveyor system communication protocol before passing the wrapped data packet 112 to motor controller 28. Motor controller 28 may subsequently initiate a control sequence. Alternatively, motor controller 28 may instead enter or exit an active operational state. FIG. 5 illustrates peer-to-peer communication 114 between two proximate motor controllers 28 and 116. Motor controller 28 may initiate communication to send a signal to motor controller 116 to indicate, for example, that materials are approaching the handoff point toward the conveyor module to which motor controller 116 belongs. Rather than communicate back and forth through a central gateway, with a wireless mesh motor controller 28 may contact motor controller 116 directly. Motor controller 28 begins peer-to-peer communication by sending a modular conveyor system communication protocol data packet to an adapter board 110. The adapter board 110 transmits the data packet via an RS-232 or similar serial connection to a mote 108 with wireless mesh circuitry 58. After receiving the serial data packet from adapter board 110, mote 108 wraps the data packet using the 802.15.4 wireless protocol and wirelessly transmits the wrapped data packet 118 over peer-to-peer communication link 120 to another mote 108 having similar wireless mesh circuitry 58. The other mote 108 receives the wrapped data packet 118, unwrapping and transmitting the data packet via an RS-232 or similar serial connection to another adapter board 110. The other adapter board 110 receives the data packet and passes the data to motor controller 116. Having received a message from motor controller 28, motor controller 116 may react to the message by taking some predefined action, such as driving a motor to activate a conveyor belt in preparation for material handoff. Motor controller 116 may also transmit a return message to motor controller 28 in substantially the same manner as the transmission of the original message. Referring to FIG. 6, gateway communication configuration 122 illustrates one manner by which communication between a motor controller 28 of a conveyor module and a main supervisory system may transpire. To initiate communication, a supervisory system 124 running on a remote control and monitoring system 52 may generate a data packet 126 using a modular conveyor system communication protocol, often in response to direction from a human operator via operation interface 54 (depicted on FIG. 1) or an automated command from network 56. The remote control and monitoring system 52 passes the data packet 126 via an RS-232 or similar serial connection to a gateway 128 with wireless mesh circuitry 58. Gateway 128 wraps the data packet using the 802.15.4 wireless protocol, wirelessly transmitting the wrapped data packet 130 over supervisory communication link 96 to a mote 108 having similar wireless mesh circuitry 58. Mote 108 receives the wrapped data packet 130 before unwrapping and retransmitting the data packet via an RS-232 or similar serial connection to an adapter board 110. Adapter board 110 receives the data packet and passes the data to motor controller 28. After receiving the message from supervisory system 124, motor controller 28 may take appropriate action in response to the message. Motor controller 28 may also transmit a return message to supervisory system 124 in substantially the same manner as the transmission of the original message. Appearing on FIG. 7, supervisory mesh routing configuration 132 illustrates supervisory message routing 134 across modular conveyor system 10. When located too great a distance from gateway 128 for direct communication, a conveyor module must send messages to gateway 128 across modular conveyor system 10 components via an ad hoc wireless mesh network. The wireless mesh circuitry 58 of each conveyor module may establish an efficient path for a message to travel, illustrated in FIG. 7 as supervisory message routing 134. A message sent from a first conveyor module may travel, for example, from the wireless mesh circuitry 58 of the first conveyor module to the wireless mesh circuitry 58 of a proximate module, such as conveyor module 18. From the wireless mesh circuitry 58 of conveyor module 18, the message be forwarded to the wireless mesh circuitry 58 of another proximate conveyor module located more closely to gateway 128. Accordingly, a message may travel a much greater distance across a wireless mesh network than may be possible via a direct communication link alone. Additionally, the power needs of the wireless mesh circuitry 58 may remain comparatively small relative to the power required for a direct communication link. As illustrated in FIG. 8, a modular conveyor system configured for wireless mesh communication may offer additional advantages when a direct link from one component to another becomes obstructed. Operation of a conveyor module with wireless mesh circuitry 136 may require sending a message to conveyor module 16 with wireless mesh circuitry 138, but an obstruction 140 may preclude a direct communication link. An ad hoc wireless mesh network formed by communication links among wireless mesh circuitry 58, 136, and 138, however, may provide a means for traversing the obstruction. Accordingly, despite obstruction 140, a message may take alternate path 142 from wireless mesh circuitry 136 to wireless mesh circuitry 138. While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
|
B
|
B65
|
B65G
|
43
|
10
|
|||
11976229
|
US20080049839A1-20080228
|
Video coding method and apparatus for calculating motion vectors of the vertices of a patch of an image and transmitting information of horizontal and vertical components of the motion vectors
|
ACCEPTED
|
20080214
|
20080228
|
[]
|
H04N712
|
["H04N712"]
|
8135070
|
20071023
|
20120313
|
375
|
240160
|
98497.0
|
LEE
|
Y
|
[{"inventor_name_last": "Nakaya", "inventor_name_first": "Yuichiro", "inventor_city": "Tokyo", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Kimura", "inventor_name_first": "Junichi", "inventor_city": "Hachioji-shi", "inventor_state": "", "inventor_country": "JP"}]
|
A method and apparatus for coding an image includes calculation of motion vectors of vertices of a patch in an image being encoded and transmitting information of horizontal and vertical components of the motion vectors of the vertices and information specifying that values of the horizontal and vertical components of a motion vector for each pixel in the patch are integral multiples of 1/d of a distance between adjacent pixels, where d is an integer not less than 2.
|
1. A method of coding an image by carrying out motion compensation in which all pixels associated with a same patch are not restricted to have a common vector and horizontal and vertical components of a motion vector for each pixel can assume an arbitrary value other than an integral multiple of a distance between adjacent pixels, said method comprising the steps of: estimating motion information of a patch from an original image of a current image and a reference image; and calculating horizontal and vertical components of a motion vector for each pixel of a plurality of pixels of a predicted image from the estimated motion information of a patch with limiting of said horizontal and vertical components of a motion vector for each pixel to integer multiples of 1/d, d being an integer not less than 2 of the distance between adjacent pixels.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a video-coding/decoding system and a video coder and a video decoder used with the same system for implementing a motion compensation method in which all the pixels associated with the same patch are not restricted to have a common motion vector and in which the horizontal and vertical components of a motion vector of a pixel can assume an arbitrary value other than an integral multiple of the distance between adjacent pixels. 2. Description of the Related Art In the high-efficiency coding and decoding of image sequences, a motion compensation method utilizing the analogy between temporally-proximate frames is well known to have a great advantage in compressing the amount of information. FIGS. 1A and 1B are diagrams showing a general circuit configuration of a video coder 1 and a video decoder 2 to which the motion compensation method described above is applied. In FIG. 1A , a frame memory 2 - 1 has stored therein a reference image R providing a decoded image of the previous frame already coded. A motion estimation section 3 - 1 estimates a motion and outputs motion information using the original image I of the current frame to be coded and the reference image R read out of the frame memory 2 - 1 . A predicted image synthesis circuit 4 - 1 synthesizes a predicted image P for the original image I using the motion information and the reference image R. A subtractor 5 - 1 calculates the difference between the original image I and the predicted image P and outputs a prediction error. The prediction error is subjected to the DCT conversion or the like at a prediction error coder 6 - 1 , and transmits the prediction error information together with the motion information to the receiving end. At the same time, the prediction error information is decoded by the inverted DCT conversion or the like at a prediction error decoder 7 - 1 . An adder 8 - 1 adds the coded prediction error to the predicted image P and outputs a decoded image of the current frame. The decoded image of the current frame is newly stored in the memory 2 - 1 as a reference image R. In FIG. 1B , a frame memory 2 - 2 has stored therein a reference image R providing a decoded image of the previous frame. A synthesis circuit 4 - 2 synthesizes a predicted image P using the reference image R read out of the frame memory 2 - 2 and the motion information received. The received prediction error information is decoded by being subjected to the inverse DCT conversion or the like by a prediction error decoder 7 - 2 . An adder 8 - 2 adds the decoded prediction error to the predicted image P and outputs a decoded image of the current frame. The decoded image of the current frame is newly stored in the frame memory 2 - 2 as a reference image P. A motion compensation method constituting the main stream of the current video coding and decoding techniques depends on the “block matching of half-pixel accuracy” employed by MPEG1 and MPEG2 providing the international standard of video coding/decoding method. In the “block matching of half-pixel accuracy”, the original image of the current frame to be coded is segmented into a number n of blocks at the motion estimation section 3 - 1 in FIG. 1A , and a motion vector is determined for each block as a motion information. The horizontal and vertical components of this motion vector have a minimum unit length equal to one-half of the distance between horizontally and vertically adjacent pixels, respectively. In the description that follows, let the horizontal component of the motion vector of the ith block (1.ltoreq.i.ltoreq.n) be ui and the vertical component thereof be vi. In a method most widely used for estimating the motion vector (ui,vi), a search range such as −15.ltoreq.ui.ltoreq.15, −15.ltoreq.vi.ltoreq.15 is predetermined, and a motion vector (ui,vi) which minimizes the prediction error Ei(ui,vi) in the block is searched for. The prediction error Ei(ui,vi) is expressed by Equation 1 using a mean absolute error (MAE) as an evaluation standard. Ei function. (ui,vi)=1 Ni .times. (x, y) .di-elect cons. B1 .times. .times. I .function. (x, y) R function. (x−ui, y−vi) (1) In Equation 1, I(x,y) denotes the original image of the current frame to be coded, and R(x, y) a reference image stored in memory. In this equation, it is assumed that pixels exist at points of which the x and y coordinates are an integer on the original image I and the reference image R. Bi designates the pixels contained in the ith block of the original image I, and Ni the number of pixels contained in the ith block of the original image I. The process of evaluating the prediction error for motion vectors varying from one block to another and searching for a motion vector associated with the smallest prediction error is called the matching. Also, the process of calculating Ei(ui,vi) for all vectors (ui,vi) conceivable within a predetermined search range and searching for the minimum value of the vector is called the full search. In the motion estimation for the “block matching of half-pixel accuracy”, ui and vi are determined with one half of the distance between adjacent pixels, i.e., ½ as a minimum unit. As a result, (x−ui, y−vi) is not necessarily an integer, and a luminance value of a point lacking a pixel must actually be determined on the reference image R when calculating the prediction error using Equation 1. The process for determining the luminance value of a point lacking a pixel is called the interpolation, and the point where interpolation is effected is referred to as an interpolated point or an intermediate point. A bilinear interpolation is often used as an interpolation process using four pixels around the interpolated point. When the process of bilinear interpolation is described in a formula, the luminance value R(x+p,y+q) at the interpolated point (x+p,y+q) of the reference image R can be expressed by Equation 2 with the fractional components of the coordinate value of the interpolated point given as p and q (0.ltoreq.p.ltoreq.1, 0.ltoreq.q<1). R(x+p,y+q)=(1−q){(1−p)R(x,y)+pR(x+1,y)}+q{(1−p)R(x,y+1)+pR(x+1,y+1)} (2). In the motion estimation by “block matching of half-pixel accuracy”, a two-step search is widely used in which, first, the full-search of single-pixel accuracy is effected for a wide search range to estimate a motion vector approximately, followed by the full search of half-pixel accuracy for a very small range defined by, say, plus/minus a half pixel in horizontal and vertical directions around the motion vector. In the second-step search, a method is frequently used in which the luminance value of an interpolated point on the reference image R is determined in advance. An example of the process according to this method is shown in FIGS. 2A , B. C and D. In this example, a block containing four pixels each in longitudinal and lateral directions is used. In FIGS. 2A , B, C and D, the points assuming an integral coordinate value and originally having a pixel in a reference image are expressed by a white circle, large circle, and the interpolated points for which a luminance value is newly determined are represented by X. Also, the pixels in a block of the original image of the current frame are expressed by a white square quadrature. The motion vector obtained by the first-step search is assumed to be (uc,vc). FIG. 2A shows the state of matching when the motion vector is (uc,uv) in the first-step search. The prediction error is evaluated between each pair of large circle and quadrature. overlapped. FIGS. 2B , C and D show the case in which the motion vector is (uc+½,vc), (uc+½,vc+½), (uc-½,vc-½) in the second-step search. The prediction error is evaluated between each overlapped pair of X and quadrature. in FIGS. 2B , C and D. As seen from these drawings, in the case where the range for the second-step search is +−½ pixel each in longitudinal and lateral directions, the matching process for eight motion vectors ((uc,vc+½), (uc+½,vc), (uc+½,vc+½), (uc−½, vc.+−.½) can be accomplished by determining the luminance value of 65 (=the number of X in each drawing) interpolated points in advance. In the process, all the interpolated points of which the luminance value was determined are used for matching. On the other hand, assuming that the interpolation calculation is made on a reference image each time of matching, a total of 128 (=16.times.8, in which 16 is the number of white squares in FIGS. 2B , C and D, and 8 is the number of times the matching is made) interpolations would be required. As described above, the number of interpolation operations can be reduced by determining the luminance value of the interpolated points on the reference image R in advance by reason of the fact that the same interpolated point on the reference image R is used a plurality of times. Also, in the “block matching of half-pixel accuracy”, a predicted image is synthesized using the relation of Equation 3 in the synthesis circuits 4 - 1 , 4 - 2 shown in FIGS. 1A and 1B . P(x,y)=R(x−ui,y−vi),(x,y).epsilon.Bi(1.ltoreq.i.ltoreq.n) (3) In Equation 3, P(x,y) shows an original image I(x,y) of the current frame to be coded which is predicted by use of the reference image R(x,y) and the motion vector (ui,vi). Also, assuming that the predicted image P is segmented into a number n of blocks corresponding to the original image I, Bi represents a pixel contained in the ith block of the predicted image P. In the “block matching of half-pixel accuracy”, as described above, the value of (x−ui,y−vi) is not necessarily an integer, and therefore the interpolation process such as the bilinear interpolation using Equation 2 is carried out in synthesizing a predicted image. The “block matching of half-pixel accuracy” is currently widely used as a motion compensation method. Applications requiring an information compression ratio higher than MPEG1 and MPEG2, however, demand an even more sophisticated motion compensation method. The disadvantage of the “block matching” method is that all the pixels in the same block are required to have the same motion vector. In order to solve this problem, a motion compensation method allowing adjacent pixels to have different motion vectors has recently been proposed. The “motion compensation based on spatial transformation” which is an example of such a method is briefly explained below. In the “motion compensation based on spatial transformation”, the relation between the predicted image P and the reference image R in synthesizing a predicted image at the synthesis circuit 4 - 1 , 4 - 2 in FIGS. 1A and 1B is expressed by Equation 4 below. in-line-formulae description="In-line Formulae" end="lead"? P ( x,y )= R ( fi ( x,y ), gi ( x,y )),( x,y ).epsilon. Pi ( 1.ltoreq. i .ltoreq. n ) (4). in-line-formulae description="In-line Formulae" end="tail"? In Equation 4, on the assumption that the predicted image P is segmented into a number n of patches corresponding to the original image I, Pi represents a pixel contained in the ith patch of the predicted image P. Also, the transformation functions fi(x,y) and gi(x,y) represent a spatial correspondence between the predicted image P and the reference image R. The motion vector for a pixel (x,y) in Pi can be represented by (x-fi(x,y),y-gi(x,y)). The predicted image P is synthesized by calculating the transformation functions fi(x,y), gi(x,y) with respect to each pixel in each patch and determining the luminance value of corresponding points in the reference image R in accordance with Equation 4. In the process, (fi(x,y), gi(x,y)) is not necessarily an integer, and therefore the interpolation process such as the bilinear interpolation is performed using Equation 3 as in the case of the “block matching of half-pixel accuracy”. The “block matching” can be interpreted as a special case of the “motion compensation based on spatial transformation” in which the transformation function is a constant. Nevertheless, the words “motion compensation based on spatial transformation” as used in the present specification are not assumed to include the “block matching”. Examples of the transformation functions fi(x,y), gi(x,y) in the “motion compensation based on spatial transformation” include the case using the affine transformation shown in Equation 5 (refer to “Basic Study of Motion Compensation Based on Triangular Patches” by Nakaya, et al., Technical Report of IEICE, IE90-106, H2-03) shown below fi(x,y)=ai1x+ai2y+ai3 gi(x,y)=ai4x+ai5y+ai6 (5) the case using the bilinear transformation given in Equation 6 (G. J. Sullivan and R. L. Baker, “Motion compensation for video compression using control grid interpolation”, Proc. ICASSP '91, M9.1, pp. 2713-2716, 1991-05) shown below fi(x,y)=bi1xy+bi2x+bi3y+bi4 gi(x,y)=bi5xy+bi6x+bi7y+bi8 (6) and the case using the perspective transformation given in Equation 7 (V. Seferdis and M. Ghanbari, “General approach to block-matching motion estimation”, Optical Engineering, vol. 32, no. 7, pp. 1464-1474, 1993-07) shown below fi function. (x, y)=ci .times. .times. 4 .times. .times. x+ci .times. .times. 5 .times. .times. y+ci .times. .times. 6 ci .times. .times. 1 .times. .times. x+ci .times. .times. 2 .times. .times. y+ci .times. .times. 3 .times. .times. gi function. (x, y)=ci .times. times. 7 .times. .times. x+ci .times. .times. 8 .times. y+ci .times. .times. 9 ci .times. .times. 1 .times. .times. x+ci .times. .times. 2 .times. .times. y+ci .times. .times. 3 (7). In Equations 5, 6 and 7, aij, bij, cij (j: 1 to 9) designate motion parameters estimated for each patch as motion information at the motion estimation section 3 - 1 in FIG. 1A . An image identical to the predicted image P produced at the synthesis circuit 4 - 1 of the video coder 1 can be obtained at the synthesis circuit 4 - 2 of the video decoder 2 at the receiving end in such a manner that information capable of specifying the motion parameter of the transformation function for each patch in some form or other is transmitted by the video coder 1 as motion information to the video decoder 2 at the receiving end. Assume, for example, that the affine transformation (Equation 5) is used as the transformation function and the patch is triangular in shape. In such a case, six motion parameters can be transmitted directly as motion information. Alternatively, the motion vectors of three vertices of a patch may be transmitted so that six motion parameters indicated by Equation 5 are calculated from the motion vectors of the three vertices at the receiving end. Also, in the case where the bilinear transformation (Equation 6) is used as the transformation function, the employment of a quadrilateral patch makes it possible to transmit the desired one of eight motion parameters and the motion vectors of four vertices of the patch. The following explanation refers to the case using the affine transformation (Equation 5) as the transformation function. This explanation applies substantially directly with equal effect to the case where other transformations (Equation 6, 7, etc.) are employed. Even after a transformation function is established, many variations are conceivable for the “motion compensation based on spatial transformation”. An example is shown in FIG. 3 . In this case, the motion vector is restricted to continuously change at the patch boundary. First, an original image 1202 of the current frame is segmented into a plurality of polygonal patches, thereby constituting a patch-segmented original image 1208 . The vertices of these patches are called the grid points, each of which is shared by a plurality of patches. A patch 209 in FIG. 3 , for example, is composed of grid points 210 , 211 , 212 , which function also as vertices of other patches. After the original image 1202 is segmented into a plurality of patches in this way, motion estimation is performed. In the shown example, motion estimation is performed with a reference image R 201 with respect to each grid point. As a result, each patch is deformed on the reference image R 203 after motion estimation. The patch 209 , for instance, corresponds to the deformed patch 204 . This is by reason of the fact that the grid points 205 , 206 , 207 on the original image 1208 are estimated to have been translated to the grid points 210 , 211 , 212 respectively on the reference image R 203 as a result of motion estimation. Since most of the grid points are shared by multiple patches in this example, the amount of transmitted data can be reduced by transmitting the motion vectors of the grid points rather than transmitting the affine transformation parameters of each patch. In the “motion compensation based on spatial transformation”, as in the “block matching”, it is pointed out that the motion estimation based on matching is effective. An example algorithm for motion estimation based on matching is described below. This scheme is called the “hexagonal matching” and is effectively applied to the case where the motion vector continuously changes at the patch boundary. This scheme is configured of two processes: (1) Coarse motion estimation of grid points by “block matching”; and (2) Correction of motion vector by “refinement algorithm”. In process (1), the block matching is applied to a block of a given size containing a grid point, and the motion vector of this block is determined as a coarse motion vector for the grid points existing in the particular block. The object of process (1) is nothing but to determine a coarse motion vector of a grid point and is not always achieved using the block matching. The manner in which process (2) is carried out is shown in FIG. 4 . FIG. 4 shows a part of a patch and grid points in the reference image R which corresponds to the reference image R 203 in FIG. 3 . Thus, changing the position of a grid point in FIG. 4 is indicative of changing the motion vector of the same grid point. In refining the motion vector of the grid point 301 , the first thing to do is to fix the motion vectors of the grid points 303 to 308 representing the vertices of a polygon 302 configured of all the patches involving the grid point 301 . The motion vector of the grid point 301 is changed with a predetermined search range in this way. For example, the grid point 301 is translated to the position of the grid point 309 . As a result, the prediction error within each patch contained by the polygon 302 also undergoes a change. The motion vector minimizing the prediction error within the polygon 302 in the search range is registered as a refined motion vector of the grid point 301 . The refinement of the motion vector of the grid point 301 is thus completed, and a similar operation of refinement is continued by translating to another grid point. Once all the grid points are refined, the prediction error can be further reduced by repeating the refinement from the first grid point. The appropriate number of repetitions of the refinement process is reported to be two or three. A typical search range for the refinement algorithm is .+−.3 pixels in each of horizontal and vertical directions. In such a case, a total of 49 (=7.times.7) matching operations are performed for each grid point in the polygon 302 . Since each patch is involved in the refinement algorithm for three grid points, on the other hand, it follows that a total of 147 (=49.times.3) evaluations of prediction error is performed for each pixel in a patch. Further, each repetition of this refinement process increases the number of prediction error evaluations correspondingly. Consequently, each time of prediction error evaluation, interpolation computations are carried out for the interpolated points involved on the reference image, thereby enormously increasing the amount of computations. The problem of interpolation computation in the motion estimation for the “motion compensation based on spatial transformation” is complicated due to the essential difference thereof from the similar problem in the motion estimation for the “block matching at half-pixel accuracy”. In the “motion compensation based on spatial transformation”, even when the horizontal and vertical components of the motion vector of each grid point are restricted to an integral multiple of ½, the horizontal and vertical components of the motion vector of each pixel in each patch are not necessarily an integral multiple of ½. Also, in view of the fact that the components below the decimal point of the motion vector for each pixel in each patch generally can assume an arbitrary value, the luminance value of the same interpolated point on the reference image R is rarely used a plurality of times in the matching operation. The feature of the “motion compensation based on spatial transformation” is that a numerical operation is required for determining a motion vector for each pixel. In the case where the computation accuracy varies between the transmitting and receiving ends in computing a motion vector (transformation function), a mismatch may occur in which the predicted image P obtained at the synthesis circuit 4 - 1 of the video coder 1 is different from the predicted image P produced from the synthesis circuit 4 - 2 of the video decoder 2 . This mismatch of the predicted image P has the property of accumulating at the receiving end. Even when there is only a small error for each frame, therefore, the quality of the decoded image output from the video decoding circuit 2 may be seriously affected in the end. This problem is not posed by the “block matching” in which all the pixels in a block follow the same motion vector and this particular motion vector is coded and transmitted directly as motion information. An example of employing the affine transformation (Equation 5) as a transformation function to cope with this problem is explained. A method of solving such a problem is by enhancing the computation accuracy of Equation 5 sufficiently to reduce the computation error of Equation 5 sufficiently below the quantization step size of the luminance value. A case using this solution is studied below. Assume, for example, that the luminance value is quantized in 8 bits with the quantization step size of 1 and that the maximum value of the luminance value is 255 (11111111) and the minimum value thereof is 0 (00000000). Also, assume that the luminance values of four adjacent pixels on the reference image P are R(0,0) 0, R(0,1)=0, R(1,0)=255, and R(1,1)=255, respectively. Further, it is assumed that the computation of Equation 5 is carried out to determine fi(x,y) when the horizontal and vertical coordinates of a point on the reference image R corresponding to a pixel P(x,y) on the predicted image P are given by 0<gi(x,y)<1 and 0<fi(x,y)<1, respectively. This condition is hereinafter referred to as the worst condition. Under this worst condition, a computation error more than 1/255 in magnitude of fi(x,y) always leads to an error of the quantized value of the luminance. For a mismatch to be prevented, therefore, both the video coder 1 and the video decoder 2 must be fabricated in such a manner as to secure the computation error of Equation 5 sufficiently smaller than 1/255. Improving the computation accuracy, however, generally leads to an increased number of digits for internal expression of a numerical value, thereby further complicating the computation process. In the motion compensation process, Equation 5 is computed so frequently that an increased complication of this computation process has a serious adverse effect on the total amount of information processed.
|
<SOH> SUMMARY OF THE INVENTION <EOH>With the “motion compensation based on spatial transformation”, motion estimation based on matching poses the problem of a greatly increased amount of computations required for interpolation of luminance values at points lacking a pixel on the reference image R. A more complicated computation operation is another problem which will be posed if the computation accuracy for synthesizing each predicted image P in the video coder and the video decoder is to be improved to accommodate a mismatch between a predicted image P obtained at the sending end and a predicted image P obtained at the receiving end. An object of the present invention is to realize a motion estimation process with a small amount of computations by reducing the number of calculations for interpolation of luminance values. Another object of the invention is to provide a method of reducing the computation accuracy required for computing the transformation function at the time of synthesizing a predicted image P and also preventing the mismatch between the predicted images P attributable to the computation accuracy of the transformation function. Prior to motion estimation, a high-resolution reference image R′ is prepared for which the luminance value of a point having x and y coordinates equal to an integral multiple of 1/m1 and 1/m2 (m1 and m2 are positive integers) respectively is determined by interpolation on the reference image R. It follows therefore that in the high-resolution reference image R′, pixels exist at points whose x and y coordinate values are an integral multiple of 1/m1 and 1/m2 respectively. In the case where the luminance value of the reference image R at a position having a coordinate value other than an integer becomes required in the process of motion estimation, such a value is approximated by the luminance value of a pixel existing at a position nearest to the particular coordinate in the high-resolution reference image R′. The object of reducing the number of interpolation computations thus is achieved. In the above-mentioned process for preparing the high-resolution reference image R′, interpolation computations in the number of m1.times.m2−1 per pixel of the original image I are required. Once the interpolation process for achieving a high resolution is completed, however, the motion estimation process does not require any further computations for interpolation. In the case of the “motion compensation based on spatial transformation” described with reference to the related art above, more than 147 interpolation computations is required for each pixel in the motion estimation. When it is assumed that m1=m2=2, the number of required interpolation computations is not more than three per pixel or about one fiftieth of the conventional requirement. Even when m1=m2=4, the number of required interpolation computations is only 15, which is as small as about one tenth. The computation amount thus can be reduced remarkably. Also, assume that the horizontal and vertical components of the motion vector of each pixel used for synthesizing the predicted image P in the video coder and the video decoder are defined to take a value equivalent only to an integral multiple of 1/d1 or 1/d2 (d1 and d2 being integers) respectively of the distance between adjacent pixels. The object of reducing the required computation accuracy of the transformation function and preventing a mismatch is thus achieved. In the case where the above-mentioned rule on motion vectors is employed, the magnitude of the computation error of the transformation function fi(x,y) always leading to an error of the quantization value of luminance under the “worst condition” described with reference to the related art above is 1/d1. Suppose d1=4, for example, the risk of causing a mismatch of the predicted images under the “worst condition” is maintained substantially at the same level even when the computation accuracy of fi(x,y) is reduced by 6 bits as compared with the proposed solution described above with reference to the related art. The foregoing and other objects, advantages, manner of operation and novel features of the present invention will be understood from the following detailed description when read in conjunction with the accompanying drawings.
|
CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation of application Ser. No. 11/155,570, filed Jun. 20, 2005, now U.S. Pat. No. 7,133,454; which is a continuation of application Ser. No. 10/342,273, filed Jan. 15, 2005, now U.S. Pat. No. 6,928,117; which is a continuation of application Ser. No. 09/994,728, filed Nov. 28, 2001, now U.S. Pat. No. 6,542,548; which is a divisional application of application Ser. No. 09/863,428, filed May 24, 2001, now U.S. Pat. No. 6,516,033; which is a divisional of application Ser. No. 09/626,788, filed Jul. 26, 2000, now U.S. Pat. No. 6,285,713; which is a continuation of application Ser. No. 09/364,255, filed Jul. 30, 1999, now U.S. Pat. No. 6,134,271; which is a continuation of application Ser. No. 08/903,199, filed Jul. 15, 1997, now U.S. Pat. No. 5,963,259; which is a continuation of application Ser. No. 08/516,218, filed Aug. 17, 1995, now U.S. Pat. No. 5,684,538, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video-coding/decoding system and a video coder and a video decoder used with the same system for implementing a motion compensation method in which all the pixels associated with the same patch are not restricted to have a common motion vector and in which the horizontal and vertical components of a motion vector of a pixel can assume an arbitrary value other than an integral multiple of the distance between adjacent pixels. 2. Description of the Related Art In the high-efficiency coding and decoding of image sequences, a motion compensation method utilizing the analogy between temporally-proximate frames is well known to have a great advantage in compressing the amount of information. FIGS. 1A and 1B are diagrams showing a general circuit configuration of a video coder 1 and a video decoder 2 to which the motion compensation method described above is applied. In FIG. 1A, a frame memory 2-1 has stored therein a reference image R providing a decoded image of the previous frame already coded. A motion estimation section 3-1 estimates a motion and outputs motion information using the original image I of the current frame to be coded and the reference image R read out of the frame memory 2-1. A predicted image synthesis circuit 4-1 synthesizes a predicted image P for the original image I using the motion information and the reference image R. A subtractor 5-1 calculates the difference between the original image I and the predicted image P and outputs a prediction error. The prediction error is subjected to the DCT conversion or the like at a prediction error coder 6-1, and transmits the prediction error information together with the motion information to the receiving end. At the same time, the prediction error information is decoded by the inverted DCT conversion or the like at a prediction error decoder 7-1. An adder 8-1 adds the coded prediction error to the predicted image P and outputs a decoded image of the current frame. The decoded image of the current frame is newly stored in the memory 2-1 as a reference image R. In FIG. 1B, a frame memory 2-2 has stored therein a reference image R providing a decoded image of the previous frame. A synthesis circuit 4-2 synthesizes a predicted image P using the reference image R read out of the frame memory 2-2 and the motion information received. The received prediction error information is decoded by being subjected to the inverse DCT conversion or the like by a prediction error decoder 7-2. An adder 8-2 adds the decoded prediction error to the predicted image P and outputs a decoded image of the current frame. The decoded image of the current frame is newly stored in the frame memory 2-2 as a reference image P. A motion compensation method constituting the main stream of the current video coding and decoding techniques depends on the “block matching of half-pixel accuracy” employed by MPEG1 and MPEG2 providing the international standard of video coding/decoding method. In the “block matching of half-pixel accuracy”, the original image of the current frame to be coded is segmented into a number n of blocks at the motion estimation section 3-1 in FIG. 1A, and a motion vector is determined for each block as a motion information. The horizontal and vertical components of this motion vector have a minimum unit length equal to one-half of the distance between horizontally and vertically adjacent pixels, respectively. In the description that follows, let the horizontal component of the motion vector of the ith block (1.ltoreq.i.ltoreq.n) be ui and the vertical component thereof be vi. In a method most widely used for estimating the motion vector (ui,vi), a search range such as −15.ltoreq.ui.ltoreq.15, −15.ltoreq.vi.ltoreq.15 is predetermined, and a motion vector (ui,vi) which minimizes the prediction error Ei(ui,vi) in the block is searched for. The prediction error Ei(ui,vi) is expressed by Equation 1 using a mean absolute error (MAE) as an evaluation standard. Ei function. (ui,vi)=1 Ni .times. (x, y) .di-elect cons. B1 .times. .times. I .function. (x, y) R function. (x−ui, y−vi) (1) In Equation 1, I(x,y) denotes the original image of the current frame to be coded, and R(x, y) a reference image stored in memory. In this equation, it is assumed that pixels exist at points of which the x and y coordinates are an integer on the original image I and the reference image R. Bi designates the pixels contained in the ith block of the original image I, and Ni the number of pixels contained in the ith block of the original image I. The process of evaluating the prediction error for motion vectors varying from one block to another and searching for a motion vector associated with the smallest prediction error is called the matching. Also, the process of calculating Ei(ui,vi) for all vectors (ui,vi) conceivable within a predetermined search range and searching for the minimum value of the vector is called the full search. In the motion estimation for the “block matching of half-pixel accuracy”, ui and vi are determined with one half of the distance between adjacent pixels, i.e., ½ as a minimum unit. As a result, (x−ui, y−vi) is not necessarily an integer, and a luminance value of a point lacking a pixel must actually be determined on the reference image R when calculating the prediction error using Equation 1. The process for determining the luminance value of a point lacking a pixel is called the interpolation, and the point where interpolation is effected is referred to as an interpolated point or an intermediate point. A bilinear interpolation is often used as an interpolation process using four pixels around the interpolated point. When the process of bilinear interpolation is described in a formula, the luminance value R(x+p,y+q) at the interpolated point (x+p,y+q) of the reference image R can be expressed by Equation 2 with the fractional components of the coordinate value of the interpolated point given as p and q (0.ltoreq.p.ltoreq.1, 0.ltoreq.q<1). R(x+p,y+q)=(1−q){(1−p)R(x,y)+pR(x+1,y)}+q{(1−p)R(x,y+1)+pR(x+1,y+1)} (2). In the motion estimation by “block matching of half-pixel accuracy”, a two-step search is widely used in which, first, the full-search of single-pixel accuracy is effected for a wide search range to estimate a motion vector approximately, followed by the full search of half-pixel accuracy for a very small range defined by, say, plus/minus a half pixel in horizontal and vertical directions around the motion vector. In the second-step search, a method is frequently used in which the luminance value of an interpolated point on the reference image R is determined in advance. An example of the process according to this method is shown in FIGS. 2A, B. C and D. In this example, a block containing four pixels each in longitudinal and lateral directions is used. In FIGS. 2A, B, C and D, the points assuming an integral coordinate value and originally having a pixel in a reference image are expressed by a white circle, large circle, and the interpolated points for which a luminance value is newly determined are represented by X. Also, the pixels in a block of the original image of the current frame are expressed by a white square quadrature. The motion vector obtained by the first-step search is assumed to be (uc,vc). FIG. 2A shows the state of matching when the motion vector is (uc,uv) in the first-step search. The prediction error is evaluated between each pair of large circle and quadrature. overlapped. FIGS. 2B, C and D show the case in which the motion vector is (uc+½,vc), (uc+½,vc+½), (uc-½,vc-½) in the second-step search. The prediction error is evaluated between each overlapped pair of X and quadrature. in FIGS. 2B, C and D. As seen from these drawings, in the case where the range for the second-step search is +−½ pixel each in longitudinal and lateral directions, the matching process for eight motion vectors ((uc,vc+½), (uc+½,vc), (uc+½,vc+½), (uc−½, vc.+−.½) can be accomplished by determining the luminance value of 65 (=the number of X in each drawing) interpolated points in advance. In the process, all the interpolated points of which the luminance value was determined are used for matching. On the other hand, assuming that the interpolation calculation is made on a reference image each time of matching, a total of 128 (=16.times.8, in which 16 is the number of white squares in FIGS. 2B, C and D, and 8 is the number of times the matching is made) interpolations would be required. As described above, the number of interpolation operations can be reduced by determining the luminance value of the interpolated points on the reference image R in advance by reason of the fact that the same interpolated point on the reference image R is used a plurality of times. Also, in the “block matching of half-pixel accuracy”, a predicted image is synthesized using the relation of Equation 3 in the synthesis circuits 4-1, 4-2 shown in FIGS. 1A and 1B. P(x,y)=R(x−ui,y−vi),(x,y).epsilon.Bi(1.ltoreq.i.ltoreq.n) (3) In Equation 3, P(x,y) shows an original image I(x,y) of the current frame to be coded which is predicted by use of the reference image R(x,y) and the motion vector (ui,vi). Also, assuming that the predicted image P is segmented into a number n of blocks corresponding to the original image I, Bi represents a pixel contained in the ith block of the predicted image P. In the “block matching of half-pixel accuracy”, as described above, the value of (x−ui,y−vi) is not necessarily an integer, and therefore the interpolation process such as the bilinear interpolation using Equation 2 is carried out in synthesizing a predicted image. The “block matching of half-pixel accuracy” is currently widely used as a motion compensation method. Applications requiring an information compression ratio higher than MPEG1 and MPEG2, however, demand an even more sophisticated motion compensation method. The disadvantage of the “block matching” method is that all the pixels in the same block are required to have the same motion vector. In order to solve this problem, a motion compensation method allowing adjacent pixels to have different motion vectors has recently been proposed. The “motion compensation based on spatial transformation” which is an example of such a method is briefly explained below. In the “motion compensation based on spatial transformation”, the relation between the predicted image P and the reference image R in synthesizing a predicted image at the synthesis circuit 4-1, 4-2 in FIGS. 1A and 1B is expressed by Equation 4 below. P(x,y)=R(fi(x,y),gi(x,y)),(x,y).epsilon.Pi (1.ltoreq.i.ltoreq.n) (4). In Equation 4, on the assumption that the predicted image P is segmented into a number n of patches corresponding to the original image I, Pi represents a pixel contained in the ith patch of the predicted image P. Also, the transformation functions fi(x,y) and gi(x,y) represent a spatial correspondence between the predicted image P and the reference image R. The motion vector for a pixel (x,y) in Pi can be represented by (x-fi(x,y),y-gi(x,y)). The predicted image P is synthesized by calculating the transformation functions fi(x,y), gi(x,y) with respect to each pixel in each patch and determining the luminance value of corresponding points in the reference image R in accordance with Equation 4. In the process, (fi(x,y), gi(x,y)) is not necessarily an integer, and therefore the interpolation process such as the bilinear interpolation is performed using Equation 3 as in the case of the “block matching of half-pixel accuracy”. The “block matching” can be interpreted as a special case of the “motion compensation based on spatial transformation” in which the transformation function is a constant. Nevertheless, the words “motion compensation based on spatial transformation” as used in the present specification are not assumed to include the “block matching”. Examples of the transformation functions fi(x,y), gi(x,y) in the “motion compensation based on spatial transformation” include the case using the affine transformation shown in Equation 5 (refer to “Basic Study of Motion Compensation Based on Triangular Patches” by Nakaya, et al., Technical Report of IEICE, IE90-106, H2-03) shown below fi(x,y)=ai1x+ai2y+ai3 gi(x,y)=ai4x+ai5y+ai6 (5) the case using the bilinear transformation given in Equation 6 (G. J. Sullivan and R. L. Baker, “Motion compensation for video compression using control grid interpolation”, Proc. ICASSP '91, M9.1, pp. 2713-2716, 1991-05) shown below fi(x,y)=bi1xy+bi2x+bi3y+bi4 gi(x,y)=bi5xy+bi6x+bi7y+bi8 (6) and the case using the perspective transformation given in Equation 7 (V. Seferdis and M. Ghanbari, “General approach to block-matching motion estimation”, Optical Engineering, vol. 32, no. 7, pp. 1464-1474, 1993-07) shown below fi function. (x, y)=ci .times. .times. 4 .times. .times. x+ci .times. .times. 5 .times. .times. y+ci .times. .times. 6 ci .times. .times. 1 .times. .times. x+ci .times. .times. 2 .times. .times. y+ci .times. .times. 3 .times. .times. gi function. (x, y)=ci .times. times. 7 .times. .times. x+ci .times. .times. 8 .times. y+ci .times. .times. 9 ci .times. .times. 1 .times. .times. x+ci .times. .times. 2 .times. .times. y+ci .times. .times. 3 (7). In Equations 5, 6 and 7, aij, bij, cij (j: 1 to 9) designate motion parameters estimated for each patch as motion information at the motion estimation section 3-1 in FIG. 1A. An image identical to the predicted image P produced at the synthesis circuit 4-1 of the video coder 1 can be obtained at the synthesis circuit 4-2 of the video decoder 2 at the receiving end in such a manner that information capable of specifying the motion parameter of the transformation function for each patch in some form or other is transmitted by the video coder 1 as motion information to the video decoder 2 at the receiving end. Assume, for example, that the affine transformation (Equation 5) is used as the transformation function and the patch is triangular in shape. In such a case, six motion parameters can be transmitted directly as motion information. Alternatively, the motion vectors of three vertices of a patch may be transmitted so that six motion parameters indicated by Equation 5 are calculated from the motion vectors of the three vertices at the receiving end. Also, in the case where the bilinear transformation (Equation 6) is used as the transformation function, the employment of a quadrilateral patch makes it possible to transmit the desired one of eight motion parameters and the motion vectors of four vertices of the patch. The following explanation refers to the case using the affine transformation (Equation 5) as the transformation function. This explanation applies substantially directly with equal effect to the case where other transformations (Equation 6, 7, etc.) are employed. Even after a transformation function is established, many variations are conceivable for the “motion compensation based on spatial transformation”. An example is shown in FIG. 3. In this case, the motion vector is restricted to continuously change at the patch boundary. First, an original image 1202 of the current frame is segmented into a plurality of polygonal patches, thereby constituting a patch-segmented original image 1208. The vertices of these patches are called the grid points, each of which is shared by a plurality of patches. A patch 209 in FIG. 3, for example, is composed of grid points 210, 211, 212, which function also as vertices of other patches. After the original image 1202 is segmented into a plurality of patches in this way, motion estimation is performed. In the shown example, motion estimation is performed with a reference image R201 with respect to each grid point. As a result, each patch is deformed on the reference image R203 after motion estimation. The patch 209, for instance, corresponds to the deformed patch 204. This is by reason of the fact that the grid points 205, 206, 207 on the original image 1208 are estimated to have been translated to the grid points 210, 211, 212 respectively on the reference image R203 as a result of motion estimation. Since most of the grid points are shared by multiple patches in this example, the amount of transmitted data can be reduced by transmitting the motion vectors of the grid points rather than transmitting the affine transformation parameters of each patch. In the “motion compensation based on spatial transformation”, as in the “block matching”, it is pointed out that the motion estimation based on matching is effective. An example algorithm for motion estimation based on matching is described below. This scheme is called the “hexagonal matching” and is effectively applied to the case where the motion vector continuously changes at the patch boundary. This scheme is configured of two processes: (1) Coarse motion estimation of grid points by “block matching”; and (2) Correction of motion vector by “refinement algorithm”. In process (1), the block matching is applied to a block of a given size containing a grid point, and the motion vector of this block is determined as a coarse motion vector for the grid points existing in the particular block. The object of process (1) is nothing but to determine a coarse motion vector of a grid point and is not always achieved using the block matching. The manner in which process (2) is carried out is shown in FIG. 4. FIG. 4 shows a part of a patch and grid points in the reference image R which corresponds to the reference image R203 in FIG. 3. Thus, changing the position of a grid point in FIG. 4 is indicative of changing the motion vector of the same grid point. In refining the motion vector of the grid point 301, the first thing to do is to fix the motion vectors of the grid points 303 to 308 representing the vertices of a polygon 302 configured of all the patches involving the grid point 301. The motion vector of the grid point 301 is changed with a predetermined search range in this way. For example, the grid point 301 is translated to the position of the grid point 309. As a result, the prediction error within each patch contained by the polygon 302 also undergoes a change. The motion vector minimizing the prediction error within the polygon 302 in the search range is registered as a refined motion vector of the grid point 301. The refinement of the motion vector of the grid point 301 is thus completed, and a similar operation of refinement is continued by translating to another grid point. Once all the grid points are refined, the prediction error can be further reduced by repeating the refinement from the first grid point. The appropriate number of repetitions of the refinement process is reported to be two or three. A typical search range for the refinement algorithm is .+−.3 pixels in each of horizontal and vertical directions. In such a case, a total of 49 (=7.times.7) matching operations are performed for each grid point in the polygon 302. Since each patch is involved in the refinement algorithm for three grid points, on the other hand, it follows that a total of 147 (=49.times.3) evaluations of prediction error is performed for each pixel in a patch. Further, each repetition of this refinement process increases the number of prediction error evaluations correspondingly. Consequently, each time of prediction error evaluation, interpolation computations are carried out for the interpolated points involved on the reference image, thereby enormously increasing the amount of computations. The problem of interpolation computation in the motion estimation for the “motion compensation based on spatial transformation” is complicated due to the essential difference thereof from the similar problem in the motion estimation for the “block matching at half-pixel accuracy”. In the “motion compensation based on spatial transformation”, even when the horizontal and vertical components of the motion vector of each grid point are restricted to an integral multiple of ½, the horizontal and vertical components of the motion vector of each pixel in each patch are not necessarily an integral multiple of ½. Also, in view of the fact that the components below the decimal point of the motion vector for each pixel in each patch generally can assume an arbitrary value, the luminance value of the same interpolated point on the reference image R is rarely used a plurality of times in the matching operation. The feature of the “motion compensation based on spatial transformation” is that a numerical operation is required for determining a motion vector for each pixel. In the case where the computation accuracy varies between the transmitting and receiving ends in computing a motion vector (transformation function), a mismatch may occur in which the predicted image P obtained at the synthesis circuit 4-1 of the video coder 1 is different from the predicted image P produced from the synthesis circuit 4-2 of the video decoder 2. This mismatch of the predicted image P has the property of accumulating at the receiving end. Even when there is only a small error for each frame, therefore, the quality of the decoded image output from the video decoding circuit 2 may be seriously affected in the end. This problem is not posed by the “block matching” in which all the pixels in a block follow the same motion vector and this particular motion vector is coded and transmitted directly as motion information. An example of employing the affine transformation (Equation 5) as a transformation function to cope with this problem is explained. A method of solving such a problem is by enhancing the computation accuracy of Equation 5 sufficiently to reduce the computation error of Equation 5 sufficiently below the quantization step size of the luminance value. A case using this solution is studied below. Assume, for example, that the luminance value is quantized in 8 bits with the quantization step size of 1 and that the maximum value of the luminance value is 255 (11111111) and the minimum value thereof is 0 (00000000). Also, assume that the luminance values of four adjacent pixels on the reference image P are R(0,0) 0, R(0,1)=0, R(1,0)=255, and R(1,1)=255, respectively. Further, it is assumed that the computation of Equation 5 is carried out to determine fi(x,y) when the horizontal and vertical coordinates of a point on the reference image R corresponding to a pixel P(x,y) on the predicted image P are given by 0<gi(x,y)<1 and 0<fi(x,y)<1, respectively. This condition is hereinafter referred to as the worst condition. Under this worst condition, a computation error more than 1/255 in magnitude of fi(x,y) always leads to an error of the quantized value of the luminance. For a mismatch to be prevented, therefore, both the video coder 1 and the video decoder 2 must be fabricated in such a manner as to secure the computation error of Equation 5 sufficiently smaller than 1/255. Improving the computation accuracy, however, generally leads to an increased number of digits for internal expression of a numerical value, thereby further complicating the computation process. In the motion compensation process, Equation 5 is computed so frequently that an increased complication of this computation process has a serious adverse effect on the total amount of information processed. SUMMARY OF THE INVENTION With the “motion compensation based on spatial transformation”, motion estimation based on matching poses the problem of a greatly increased amount of computations required for interpolation of luminance values at points lacking a pixel on the reference image R. A more complicated computation operation is another problem which will be posed if the computation accuracy for synthesizing each predicted image P in the video coder and the video decoder is to be improved to accommodate a mismatch between a predicted image P obtained at the sending end and a predicted image P obtained at the receiving end. An object of the present invention is to realize a motion estimation process with a small amount of computations by reducing the number of calculations for interpolation of luminance values. Another object of the invention is to provide a method of reducing the computation accuracy required for computing the transformation function at the time of synthesizing a predicted image P and also preventing the mismatch between the predicted images P attributable to the computation accuracy of the transformation function. Prior to motion estimation, a high-resolution reference image R′ is prepared for which the luminance value of a point having x and y coordinates equal to an integral multiple of 1/m1 and 1/m2 (m1 and m2 are positive integers) respectively is determined by interpolation on the reference image R. It follows therefore that in the high-resolution reference image R′, pixels exist at points whose x and y coordinate values are an integral multiple of 1/m1 and 1/m2 respectively. In the case where the luminance value of the reference image R at a position having a coordinate value other than an integer becomes required in the process of motion estimation, such a value is approximated by the luminance value of a pixel existing at a position nearest to the particular coordinate in the high-resolution reference image R′. The object of reducing the number of interpolation computations thus is achieved. In the above-mentioned process for preparing the high-resolution reference image R′, interpolation computations in the number of m1.times.m2−1 per pixel of the original image I are required. Once the interpolation process for achieving a high resolution is completed, however, the motion estimation process does not require any further computations for interpolation. In the case of the “motion compensation based on spatial transformation” described with reference to the related art above, more than 147 interpolation computations is required for each pixel in the motion estimation. When it is assumed that m1=m2=2, the number of required interpolation computations is not more than three per pixel or about one fiftieth of the conventional requirement. Even when m1=m2=4, the number of required interpolation computations is only 15, which is as small as about one tenth. The computation amount thus can be reduced remarkably. Also, assume that the horizontal and vertical components of the motion vector of each pixel used for synthesizing the predicted image P in the video coder and the video decoder are defined to take a value equivalent only to an integral multiple of 1/d1 or 1/d2 (d1 and d2 being integers) respectively of the distance between adjacent pixels. The object of reducing the required computation accuracy of the transformation function and preventing a mismatch is thus achieved. In the case where the above-mentioned rule on motion vectors is employed, the magnitude of the computation error of the transformation function fi(x,y) always leading to an error of the quantization value of luminance under the “worst condition” described with reference to the related art above is 1/d1. Suppose d1=4, for example, the risk of causing a mismatch of the predicted images under the “worst condition” is maintained substantially at the same level even when the computation accuracy of fi(x,y) is reduced by 6 bits as compared with the proposed solution described above with reference to the related art. The foregoing and other objects, advantages, manner of operation and novel features of the present invention will be understood from the following detailed description when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a diagram showing an example of a conventional video coder. FIG. 1B is a diagram showing an example of a conventional video decoder. FIG. 2A to 2D are diagrams showing an example process of the second-step search in the “block matching of half-pixel accuracy”. FIG. 3 is a diagram showing an example process for motion estimation in the “motion compensation based on spatial transformation”. FIG. 4 is a diagram showing the process according to a scheme called the “hexagonal matching” as an example of motion estimation operation in the “motion compensation based on spatial transformation”. FIG. 5 is a diagram showing an example of a video coder utilizing a high-resolution reference image. FIG. 6 is a diagram showing an example of an interpolation circuit using the bilinear interpolation for interpolation of luminance values. FIG. 7 is a diagram showing an example circuit for producing a luminance value in a high-resolution reference image from the result of computations of the transformation function in a matching circuit. FIG. 8 is a diagram showing the range of pixels used for refinement in the “hexagonal matching”. FIG. 9 is a diagram showing the range of pixels additionally required for performing the refinement following the adjacent grid points in the refinement process for the “hexagonal matching”. FIG. 10 is a diagram showing a video coder including a motion estimation section for performing motion estimation by improving the resolution of a reference image while fetching the required portions of the original image of the current frame and a reference image little by little. FIG. 11 is a diagram showing the case in which parallel processing is introduced to a scheme used for performing motion estimation while fetching the required portion of the original image of the current frame and a reference image little by little. FIG. 12 is a diagram showing an example translation and deformation of a patch in the motion compensation based on spatial transformation. FIG. 13 is a diagram showing an example method of computing the transformation function when the horizontal and vertical components of a motion vector are restricted to an integer multiple of ¼(d=4). FIG. 14 is a diagram showing an example scheme for determining the value of 1/d providing a minimum unit of the pixel motion vector by communication between the sending and receiving ends before transmission of video data. DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of performing the motion estimation operation by improving the resolution of the whole reference image R in a video coder 1 will be explained as a first embodiment. First, the luminance value of a point lacking a pixel on the reference image R is interpolated to form a high-resolution reference numeral R′. Assuming that the bilinear interpolation (Equation 3) is used as an interpolation scheme for the luminance value, the high-resolution reference numeral R′ is given by Equation 8. R′(x+s m .times. .times. 1, y+t m .times. .times. 2=(1−t m .times. .times. 2) .times. {(1−s m .times. .times. 1) .times. R .function. (x, y)+s m .times. .times. 1.times. R .function. (x+1, y )}+t m .times. .times. 2.times. {(1−s m .times. .times. 1.times. R .function. (x, y+)+s m .times. .times. 1 .times. R .function. (x+1, y+1)}(8) where it is assumed that s and t are an integral number and that 0.ltoreq.s.ltoreq.m1 and 0.ltoreq.t.Itoreq.m2. On the high-resolution reference image R′, pixels are assumed to exist at points where all of x, y, s and t are an integral number. The points where s=t=0 corresponds originally to pixels existing on the reference image R, and the luminance value of other points can be determined by interpolation. In the description that follows, an embodiment will be explained with reference to the case in which m1=m2=m (m: positive integral number) for the sake of simplicity. An example of an video coder 1 utilizing the high-resolution reference image R′ is shown in FIG. 5. The arrows in FIG. 5 indicate a data flow while address signals are not shown. In this system, a motion estimation section 401 is in charge of motion estimation. A reference image 404, after being processed at a reference image interpolation circuit 405 for improving the resolution, is stored in a frame memory 407 as a high-resolution reference image R′ 406 thereby to provide an approximated luminance value 408 to a matching circuit 409. On the other hand, the original image 1402 of the current frame is stored in the frame memory 403 and utilized for motion estimation at the matching circuit 409. The motion information 415, which is output from the matching circuit 409 is transmitted to the receiving end, is also utilized for synthesizing a predicted image P410 at a synthesis circuit 4-1 in the video coder 1. The difference between the synthesized predicted image P410 and the original image 1411 of the current frame is determined at a subtractor 5-1 and coded at a prediction error coder 6-1 as a prediction error 413 while being transmitted as a prediction error information 416. In the conventional method, the computation of the transformation function, the interpolation and the evaluation of the prediction error are all performed at a matching circuit. According to this embodiment, by contrast, the amount of computations is reduced by performing the interpolation operation in advance at the interpolation circuit 405. Also, by using the high-resolution reference image R′, the computation accuracy required for the computation of a transformation function at the matching circuit 409 can be reduced. Further, the related process can be simplified. This is due to the fact that in the case of an error occurred in the computation of a transformation function, the result of motion estimation is not affected as far as the pixels used as an approximated value on the high-resolution reference image R′ are not different. All the pixels on the high-resolution reference image R′ of which the luminance value is determined by interpolation are not necessarily used for the matching operation. This point is different from the example of the “block matching of half-pixel accuracy” described above. An example of the interpolation circuit 405 using the bilinear interpolation (Equation 8) for the interpolation of a luminance value is shown in FIG. 6 assuming that m=2. Also in this diagram, the arrows indicate the data flow, and the reference numerals identical to those in FIG. 5 denote the same component elements respectively. The input reference image signal 404 is assumed to apply a luminance value of pixels from left to right for each line downward. This signal is applied to a circuit including two pixel delay circuits 501, 502 and a line delay circuit 501, thereby producing luminance values 504 to 507 of four pixels adjacent in the four directions. These luminance values 504 to 507 are multiplied by a weighting coefficient corresponding to the interpolation position using multipliers 508 to 511 respectively, and the result is applied to adders 512 to 514. The result of addition is further applied to an adder 515 and a shift register 516 to achieve the division by 4 (four) and rounding of the quotient. As a result of the aforementioned process, the luminance values 517 to 520 for the four pixels of the high-resolution reference image R′ can be obtained as an output 406. FIG. 7 shows an example circuit for producing an approximated value R′(x′,y′) of the luminance value at an interpolated point of the reference image using the high-resolution reference image R′ in the matching circuit 409. The reference numerals identical to those in FIG. 5 denote the same component elements respectively. In the case under consideration, the fixed point binary representation of the coordinates fi(x,y) 601 and gi(x,y) 602 on the reference image R are assumed to be given by calculating the transformation function (Equations 5 to 7). Also, it is assumed that m is 2 as in the case of FIG. 6 and that the high-resolution reference image R′ is stored in the frame memory 407. The coordinate values fi(x,y) 601 and gi(x,y) 602 are applied through an adder 603 for adding ¼ and a circuit 604 that omits the figures at the second and lower order binary places and thus are converted into an integer multiple of ½. The resulting coordinate values x′605 and y′606 correspond to the coordinate values at a point having a pixel on the high-resolution reference image R′. These coordinate values x′605 and y′606 are converted into an address of the frame memory 407 by a coordinate-address conversion circuit 607, thereby producing an intended approximated luminance value 408 from the frame memory 407. In the case under consideration, the components of the third and lower places below decimal point of the computation result of the transformation function are not used at all. It follows therefore that any computation error in a range not affecting the second and higher places below decimal point of the computation result of the transformation function does not affect the result of motion estimation. This is due to the fact that, as described above, the use of the high-resolution reference image R′ has reduced the computation accuracy required of the transformation function computation. In the first embodiment, although the number of interpolation computations is reduced, a memory capable of storing an image four times larger than the reference image R is required as the frame memory 407 for storing the high-resolution reference image R′. In view of this, a second embodiment is described below, in which although the number of interpolation computations required is increased as compared with the first embodiment, the required memory capacity is reduced. In the second method, while the required portion of the original image I and the reference image R of the current frame are fetched little by little, the reference image R is interpolated and used for motion estimation. The distance between adjacent pixels is assumed to be unity for both horizontal and vertical directions on the original image I of the current frame and the reference image R. The description below is based on the assumption that the “hexagonal matching” is used for motion estimation, and is centered on a circuit for executing the refinement operation in the “hexagonal matching”. The coarse motion estimation of grid points which constitutes another process for the “hexagonal matching”, as already explained, is carried out by executing the “block matching” for a block containing the grid points. FIG. 8 shows the position of grid points 703 to 711 in a portion of the original image I of the current frame. Assume that the interval between grid points is Ng in horizontal and vertical directions and the search range of the motion vector for each grid point is +−.Ns in horizontal and vertical directions. The “hexagonal matching” for the grid point 703 can be refined by using the pixels contained in the range 701 of 2Ng+2Ns in horizontal and vertical-directions of the reference image R and the range 702 (shadowed portion) of 2Ng in horizontal and vertical directions of the original image of the current frame. Actually, however, a smaller range will do, even though a square area is used to simplify the process. A device for performing the refinement process can thus perform subsequent processes independently of the external frame memory by reading the luminance values of the pixels contained in this range in advance. Also, in this case, if the grid point 708 is refined before the grid point 703, it follows that a part of the pixels of the range 701 and range 702 has already been read in the refinement device. In such a case, as shown in FIG. 9, only the range 801 of the reference image R and the range 802 of the original image I of the current frame are additionally read. In FIG. 9, the reference numerals identical to those in FIG. 8 designate the same component parts respectively. In the process of additional reading, a portion of the data on the pixels on the original image I and the reference image R used for motion estimation of the grid point 708 becomes unnecessary. The data of the ranges 801 and 802, therefore, can be written on a memory which thus far contained the same data portion. In this way, the process can be simplified by reading only the data which becomes newly required each time of movement from left to right of a grid point for motion estimation. FIG. 10 is a diagram showing an example of the video coder 1 including a motion estimation section 909 for refining the “hexagonal matching” according to the method shown in FIGS. 8 and 9. In FIG. 10, the arrows indicate the flow of data, and the same reference numerals as those of FIG. 5 designate the same component elements respectively. The motion estimation section 909 is configured differently from but has the same function as the motion estimation section 401 in FIG. 5. The original image 1402 of the current frame and the reference image R404 of the input are stored in frame memories 1-1 and 2-1 respectively. First, an coarse motion estimation of a grid point is executed at a circuit 902, and according to the motion vector thus determined, the coordinate information of the grid point on the reference image is stored in a grid point coordinate memory 904. Then, a refinement process section 905 refines the “hexagonal matching”. The description below deals with the refinement process to be performed for the grid point 703 as in the example of FIG. 9 immediately after the grid point 708 was refined. The refinement process section 905 includes an interpolation circuit 907 and a matching circuit 906. First, the interpolation circuit 907 reads out the luminance value of pixels in a range (the range 801 in the case of FIG. 9) newly required from the frame memory 2-1 in which a reference image is stored. This information is interpolated and a high-resolution reference image R′ in a range required for motion estimation is thus produced. This high-resolution reference image R′ is applied to the matching circuit 906. The matching circuit 906 similarly reads the luminance value in a range (the range 802 in the case of FIG. 9) newly required from the frame memory 1-1 of the original image I of the current frame. The matching circuit 906 has a private memory for storing the original image I of the current frame and the high-resolution reference image R′ in a range required for refinement, and carries out the matching process using the same memory. The matching circuit 906 further reads the newly required coordinate information (coordinate information for the grid points 704, 706, 711 for the example of FIG. 9, because the coordinate information for the grid points 707, 708 and 710 are used in the previous process) for grid points in the reference image R from the coordinate point coordinate memory 904, thereby performing the refinement of the “hexagonal matching”. In accordance with the result of this process, the refined coordinate of a grid point on the reference image R (the coordinate of the grid point 703 in the example of FIG. 9) is written in the grid point coordinate memory 904. This particular process completes the refinement of the grid point 703, and the refinement process section 905 proceeds to the refinement of the grid point 704. Upon completion of the entire refinement process, the information stored in the grid point coordinate memory 904 is converted into a motion vector for each grid point at a vector computation circuit 908 and output as motion information 415. FIG. 11 shows an example of introducing the parallel operation to the process at the motion estimation section 909 of the video decoder 1 shown in FIG. 10. The reference numerals in FIG. 11 identical to those in FIG. 10 designate the same component parts respectively as in FIG. 10. In this example, there are a plurality of refinement process sections for refining the “hexagonal matching”, and each section shares the processing operation. A common data bus 1001 and an address bus 1002 are used for reading the luminance value information from the frame memory 2-1 and the frame memory 1-1 which store the original image I of the current frame and the reference image R. On the other hand, a common data bus 1005 and an address bus 1004 are used for reading information from or writing information into the grid point coordinate memory 904 which stores the coordinates of the grid points on the reference image. Through these buses, information is transferred by a circuit 902 for performing coarse motion estimation of grid points and circuits 905 and 1003 for performing the refinement operation for the “hexagonal matching”. The refinement process sections 905 and 1003 have the same configuration. The refinement operation can be carried out at higher speed by adding a refinement process section of a similar configuration. The refinement process sections can operate substantially independently of each other except for the processes of reading the luminance value information and reading/writing the grid point coordinate information. Therefore, a parallel process is secured while avoiding conflicts in memory access. In the embodiments shown in FIGS. 9, 10 and 11, the refinement process requires the interpolation computations in the number of about (2+2Ns/Ng).times.(m.times.m−1) for each pixel on the reference image R. This number is approximately (2+2Ns/Ng) times greater than the number of interpolation computations required for the first embodiment shown in FIG. 5. Since there is no need of a memory for storing the whole of the high-resolution reference image F′, however, the total memory capacity requirement can be reduced. Taking into consideration the facility of multiply and divide operations in a circuit, m1 and m2 are preferably a power of 2. With the reduction in the magnitude of m1 and m2, the circuit scale can be reduced. On the other hand, the approximation accuracy of the coordinate (motion vector) for motion estimation is adversely affected, and the prediction error is likely to be inverted in magnitude in the computation of Equation 1. The result of motion estimation thus is distorted, thereby deteriorating the performance of prediction. With the increase of m1 and m2, by contrast, the inverse phenomenon results. Taking the circuit scale into consideration, the m1 or m2 value of 4 or less is desirable. When the performance of prediction is taken into account, however, 2 or more is a desirable value of m1 and m2. Balancing between these two extremes, the appropriate value of m1 and m2 is 2 and 4 respectively. When motion estimation is carried out using a high-resolution reference image R′ with an image density of m times larger in horizontal and vertical directions, the value of the transformation functions fi(x,y) and gi(x,y) in Equations 5 to 7 is limited to an integer multiple of 1/m. In other words, this indicates that the minimum unit of the transformation function becomes 1/m of the interval between adjacent pixels. This restriction, however, is applied only to the motion estimation, and need not be observed in synthesizing the predicted image P. In the motion compensation based on spatial transformation, on the other hand, in order to prevent a mismatch of predicted images P in the video coder 1 at the sending end and in the video decoder 2 at the receiving end, some standard is required to be established with respect to the computation accuracy of the transformation function for synthesizing the predicted image P. One method of establishing such a standard is by setting a minimum unit of the transformation function for synthesizing the predicted image P as in motion estimation. In this method, the horizontal and vertical components of the motion vector of each pixel used in synthesizing the predicted image P at the synthesis circuit 4-1 of the video coder 1 and the synthesis circuit 4-2 of the video decoder 2 are specified to assume only a value equal to an integer multiple of 1/d1 and 1/d2 (d1 and d2 are positive integers) respectively of the distance between adjacent pixels. In other words, the synthesis circuits 4-1 and 4-2 are constructed to include means for rounding the computation result of the transformation functions fi(x,y) and gi(x,y) into a value equal to an integer multiple of 1/d1 and a value equal to an integer multiple of 1/d2, respectively. With reference to the case using the affine transformation (Equation 5) as a transformation function, explanation will be made below about an embodiment of a method in which the computation result of the transformation function is rounded into a value equal to an integer multiple of 1/d1 and 1/d2. For simplicity's sake, it is assumed that d1=d2=d (d: positive integer). It is also assumed that the patch is triangular in shape and that the motion vectors of three vertices of the patch are transmitted as motion information. The following description deals with the example shown in FIG. 12. A patch 1202 in the reference image R1201 is estimated to have been translated and deformed to a patch 1207 of a current frame 1206. Grid points 1203, 1204, 1205 correspond to grid points 1208, 1209, 1210, respectively. In the process, it is assumed that the coordinates of the vertices 1203, 1204, 1205 of the patch 1202 are (x1′, y1′), (x2′, y2′), (x3′, y3′) respectively, and the coordinates of the vertices 1208, 1209, 1210 of the patch 1207 are (x1, y1), (x2, y2), (x3, y3), respectively. All the coordinate values are assumed to be an integral value not negative. The motion parameter aij of Equation 5 for this patch can be expressed as (ai .times. .times. 1 ai .times. .times. 4 ai .times. .times. 2 ai .times. .times. 5 ai .times. .times. 3 ai .times. .times. 6)=1 Di .times. (y .times. .times. 2−y .times. .times. 3 y .times. .times. 3−y .times. .times. 1 y .times. .times. 1−y .times. .times. 2 x .times. .times. 3−x .times. .times. 2 x .times. .times. 1−x .times. .times. 3 x .times. .times. 2−x .times. .times. 1 x .times. .times. 2 .times. y .times. .times. 2−x times. .times. 3 .times. y .times. .times. 2 x .times. .times. 3 .times. y .times. .times. 1−x .times. .times. 1 .times. y .times. .times. 3 x .times. .times. 1 .times. y .times. .times. 2−x .times. .times. 2 .times. y .times. .times. 1) .times. (x .times. .times. 1′ y .times. .times. 1′ x .times. .times. 2′ y .times. .times. 2′ x .times. .times. 3′ y .times. .times. 3′) .times. .times. Di=x .times. .times. 1 .times. (y .times. .times. 2−y .times. .times. 3)−y .times. .times. 1 .times. (x .times. .times. 2−x .times. .times. 3)+(x .times. .times. 2 .times. y .times. .times. 3−x times. .times. 3 .times. y .times. .times. 2) (9) In this equation, any dividing operation is not performed and aij (j: 1 to 6) is retained in the form of aij=aji′/Di where both the numerator and denominator are an integer. Then, the computation result of Equation 5 can always be given in the form of a fraction having a numerator and a denominator of an integral number such as fi(x,y)=fi′(x,y)/Di and gi(x,y)=gi′(x,y)/Di. Defining the symbol “//” as representing a dividing operation between integral values (a dividing operation in which the decimal component of the computation result is discarded), it is assumed that Fi .function. (x, y)=1 d .times. {(dfi′.function. (x, y)+ki)//Di}.times. .times. Gi .function. (x, y)=1 d .times. {(dgi′.function. (x, y)+ki)//Di}(10) where ki=Di//2. Fi(x,y) and Gi(x,y) are the functions for rounding fi(x,y) and gi(x,y) respectively into a value equal to the nearest integer multiple of 1/d. In the synthesis circuit 4-1 of the video coder 1 and the synthesis circuit 4-2 of the video decoder 2, if Fi(x,y) and Gi(x,y) of Equation 7 are used in place of fi(x,y) and gi(x,y) of Equation 4, the horizontal and vertical components of the motion vector of each pixel can be restricted to assume only a value equal to an integer multiple of 1/d of the distance between adjacent pixels. Also, by using Fi(x,y) and Gi(x,y) for both the sending and the receiving ends, a mismatch of the predicted image P attributable to the error of the transformation function can be prevented in a computation comparatively low in accuracy. FIG. 13 shows the flow of operation for computing Fi(x,y) and Gi(x,y) when d=4 at the synthesis circuits 4-1, 4-2. First, when the coordinate of vertices of a patch before and after deformation are given at step 1301, functions fi′(x,y) and gi′(x,y) are defined at steps 1302 and 1304, a constant Di is determined at step 1303, and a constant ki determined at step 1305. Using these functions and constants, the values of Fi(x,y) and Gi(x,y) are calculated from the coordinate (x,y) for each pixel in the patch. When (x,y) is given in a binary integral notation, first, step 1306 computes the sum of products to determine the value of fi′(x,y) and gi′(x,y), the result of which is shifted to the left by two bits at step 1307 into a value four (=d) times as large. This result is added to ki at step 1308, and further is divided by Di at step 1309 (the figures of the computation result below the decimal point are discarded), thereby determining the values of 4Fi(x,y) and 4Gi(x,y). With these integral numbers of 4Fi(x,y) and 4Gi(x,y), step 1310 sets the decimal point between the second and third digits from the low-order place. The values of Fi(x,y) and Gi(x,y) can thus be obtained. This has the same meaning as having carried out the operation of dividing by 4. The value d can be either defined as a fixed parameter for the coding/decoding system, or can be determined as a variable by arrangement between the sending and the receiving ends before transmitting the video data. An example procedure for determining the value d by communication between the video coder 1 at the sending end and the video decoder 2 at the receiving end is shown in FIG. 14. First, step 1403 causes the sending end to notify the receiving end by communication that the allowable upper limit of d is 4 due to the hardware restriction of the video coder 1. Then, the receiving end at step 1404 notifies the sending end by communication that the upper limit of d is 2 due to the restriction of the video coder 2. As a result, the sending end decides that the optimum value of d is 2 and gives advice at step 1405 that the video data subsequently transmitted is coded with d as 2. Immediately after this advice, the sending end transmits video data at step 1406. Generally, the larger the value d, the more complicated the system hardware. Consequently, it is considered appropriate that the sending end employs the upper limit value for the sending or receiving end, whichever is lower. For this method to be realized, the video coder 1 and the video decoder 2 are required to have a function capable of accommodating the value of d equal to or lower than their own upper limit respectively. Considering the facility of multiply and divide operation, a power of 2 is recommendable as the value of d. The larger the value of d, the smaller the prediction error. In spite of this, the synthesizing process for the predicted image P becomes more complicated. Taking the performance of prediction into consideration, the desirable value of d is 2 or more. As a trade-off between the performance of prediction and the complication of the process, an appropriate value of d is specifically 2, 4, 8. The following-described modifications also obviously are included in the present invention. (1) Instead of the bilinear interpolation (Equation 2) employed in the present specification as a function for interpolation of the luminance value, other functions may be used with equal effect. With the increase in the complexity of a function, the advantage is enhanced for reducing the required number of interpolations (2) Also, instead of the affine transformation (Equation 5) which was emphasized in the present specification as a type of transformation function, other transformation functions (Equation 6 or 7) may be used with equal effect. The present invention remains effective as far as the pixels in the same patch need not follow a common motion vector and the vertical and horizontal components of the motion vector of a pixel can assume a value other than an integer multiple of the distance between adjacent pixels. Also, the invention is effective as far as the computation result of a transformation function can change according to the computation accuracy thereof. (3). The patch can be of any shape that defines a set of pixels and is not necessarily a triangle as described in the present specification. (4) With regard to the motion compensation based on spatial transformation, a method is taken up in the present specification in which the motion vector changes continuously at the boundary of a patch. In spite of this, an alternative method may be employed in which the motion parameter is transmitted directly for each patch or the discontinuity of the motion vector at the patch boundary is otherwise allowed. (5) Although the present specification employs the block matching and the hexagonal matching as a motion estimation algorithm, a method based on other matching schemes may be used with equal effect. The present invention is effective in any method in which the prediction error is evaluated a multiplicity of times. (6) In the motion compensation based on spatial transformation, the motion information transmitted may be other than motion vectors of patch vertices (grid points) as in the case of the present specification. Any motion information may be used which specifies the transformation function for each patch. The motion parameter aij of Equation 5, for example, may be transmitted directly. In the case where a motion parameter is transmitted directly in this way, the application of this invention makes it possible to reduce the accuracy of the motion parameter (to reduce the number of digits) transmitted while preventing a mismatch of the predicted image attributable to the computation accuracy of a transformation function. The smaller the value of d, the less the number of digits required of the motion parameter, with the result that the amount of transmitted information can be reduced. (7) The values of m1 and m2, which are equal to each other in the embodiment described above, may alternatively be not equal to each other. (8) Unlike in this embodiment representing a case where the values of d1 and d2 are equal to each other, they may be different from each other. (9) The present specification deals with a method in which the patch structure of the current frame is fixed and the patch of a reference image is deformed. Nevertheless, a method may alternatively be used in which the patch structure of a reference image is fixed while the patch of the current frame is deformed. (10) Unlike in the present specification employing a single reference image for synthesizing a single predicted image, a plurality of reference images may be used with equal effect. According to the present invention, it is possible to reduce the number of computations for interpolation of luminance values in the motion estimation process for a motion compensation scheme in which all the pixels associated with the same patch are not restricted to have a common motion vector but the horizontal and vertical components of the motion vector of pixels can assume an arbitrary value other than an integer multiple of the distance between adjacent pixels. Further, according to the present invention, the computation accuracy of the transformation function can be reduced while preventing a mismatch of the predicted image in synthesizing a predicted image by a motion compensation scheme in which all the pixels associated with the same patch are not restricted to have a common motion vector and the horizontal and vertical components of the motion vector of pixels can assume an arbitrary value other than an integer multiple of the distance between adjacent pixels. Furthermore, in a method of determining the values of d1 and d2 by arrangement between the sending and receiving ends before transmission of video data, an optimum image quality of a decoded image can be determined in accordance with the performance of the systems at the sending end and the receiving end.
|
H
|
H04
|
H04N
|
7
|
12
|
|||
11732295
|
US20070227506A1-20071004
|
Drive circuit for an injector arrangement and a diagnostic method
|
ACCEPTED
|
20070920
|
20071004
|
[]
|
F02M5100
|
["F02M5100", "G06F1900", "H01H4700", "H01L4100"]
|
7640918
|
20070403
|
20100105
|
123
|
479000
|
61075.0
|
HOANG
|
JOHNNY
|
[{"inventor_name_last": "Perryman", "inventor_name_first": "Louisa", "inventor_city": "Rainham", "inventor_state": "", "inventor_country": "GB"}, {"inventor_name_last": "Baker", "inventor_name_first": "Nigel P.", "inventor_city": "Canterbury", "inventor_state": "", "inventor_country": "GB"}, {"inventor_name_last": "Martin", "inventor_name_first": "Steven", "inventor_city": "Canterbury", "inventor_state": "", "inventor_country": "GB"}, {"inventor_name_last": "Sykes", "inventor_name_first": "Martin A. P.", "inventor_city": "Rainham", "inventor_state": "", "inventor_country": "GB"}]
|
The invention relates to a drive circuit for an injector arrangement comprising a fuel injector, and method of detecting faults in the drive circuit. The drive circuit comprises diagnostic means (RH, RL) that is operable to sense a measured voltage (VBIAS) between the injector and a known voltage level (VBAT, VGND). The measured voltage (VBIAS) is biased with respect to the known voltage (VBAT, VGND) to a predicted voltage (VPinjN, VBcalc) unless the drive circuit has a fault. A fault signal is provided on sensing of a measured voltage (VBIAS) that differs from the predicted voltage (VPinjN, VBcalc). The drive circuit may additionally, or alternatively, comprise diagnostic means (RF). The diagnostic means (RF) is operable to sense a detected current (Idect) and to provide a fault signal on detection of a fault, when the detected current (Idect) is at variance from a threshold current (Itrip).
|
1. A drive circuit for an injector arrangement comprising a fuel injector, the drive circuit comprising a diagnostic tool (RH, RL) operable: a) to sense a measured voltage (VBIAS) between the injector and a known voltage level (VBAT, VGND), the measured voltage (VBIAS) being biased with respect to the known voltage (VBAT, VGND) to a predicted voltage (VPinjN, VBcalc) unless the drive circuit has a fault; and b) to provide a fault signal on sensing of a measured voltage (VBIAS) that differs from the predicted voltage (VPinjN, VBcalc). 2. A drive circuit as claimed in claim 1, the drive circuit further comprising a selector switch arrangement (SQ1, SQ2) operable to select the fuel injector into the drive circuit and to deselect the fuel injector from the drive circuit. 3. A drive circuit as claimed in claim 2, wherein the predicted voltage (VBcalc) is the voltage between the fuel injector and the known voltage level (VBAT, VGND) when the injector is deselected from the drive circuit. 4. A drive circuit as claimed in claim 2, wherein the predicted voltage (VPinjN) is substantially the sum of the known voltage (VBAT, VGND) and a voltage (VPinjN) across the fuel injector when the fuel injector is selected in the drive circuit. 5. A drive circuit as claimed in claim 2, wherein the selector switch arrangement (SQ1, SQ2) is operable prior to detection of a fault. 6. A drive circuit as claimed in claim 1, wherein the signal is provided if the measured voltage (VBIAS) is outside a tolerance voltage (VBtol) of the predicted voltage (VBcalc, VPinjN). 7. A drive circuit as claimed in claim 1, wherein the measured voltage (VBIAS) is sensed across part of a potential divider connected to the injector and the known voltage (VBAT, VGND). 8. A drive circuit as claimed in claim 1, wherein the drive circuit further comprises a further diagnostic tool (RF) in a connection of the drive circuit to a ground potential (VGND), the further diagnostic tool (RF) being operable: a) to sense a detected current (Idect); and b) to provide a signal on detection of a fault, wherein the signal is provided when the detected current (Idect) is at variance from a threshold current (Itrip). 9. A drive circuit as claimed in claim 1, further comprising: i) a first charge storage device (C1) for operative connection with the fuel injector during a charging phase so as to cause a charge current to flow therethrough; ii) a second charge storage device (C2) for operative connection with the fuel injector during a discharge phase so as to permit a discharge current to flow therethrough; and iii) a switch arrangement (Q1, Q2) for operably controlling the connection of the fuel injector to the first charge storage device (C1) or the second charge storage device (C2). 10. A drive circuit as claimed in claim 9, wherein the switch arrangement comprises a charge switch (Q1) operable to close so as to activate the charging phase. 11. A drive circuit as claimed in claim 9, wherein the switch arrangement comprises a discharge switch (Q2) operable to close so as to activate the discharge phase. 12. A drive circuit as claimed in claim 9, further comprising a power supply and regeneration switch (RSQ) operable at the end of the charging phase to transfer charge from the power supply to the first charge storage device (C1), before a subsequent discharging phase. 13. A drive circuit for an injector arrangement comprising a fuel injector, the drive circuit comprising a diagnostic tool (RF) in a connection of the drive circuit to a ground potential (VGND), the diagnostic tool (RF) being operable: a) to sense a detected current (Idect); and b) to provide a signal on detection of a fault, wherein the signal is provided when the detected current (Idect) is at variance from a threshold current (Itrip). 14. A drive circuit as claimed in claim 13, wherein the signal is provided when the detected current (Idect) is greater than the threshold current (Itrip). 15. A drive circuit as claimed in claim 13, wherein the connection of the drive circuit to the ground potential (VGND) is connected to a charge storage arrangement (C1, C2). 16. A drive circuit as claimed in claim 15, wherein the charge storage arrangement comprises: i) a first charge storage device (C1) for operative connection with the fuel injector during a charging phase so as to cause a charge current to flow therethrough; and ii) a second charge storage device (C2) for operative connection with the fuel injector during a discharge phase so as to permit a discharge current to flow therethrough. 17. A drive circuit as claimed in claim 16, wherein the connection of the drive circuit to the ground potential (VGND) is connected to a switch arrangement (Q1, Q2) for operably controlling the connection of the fuel injector to the first charge storage device (C1) or the second charge storage device (C2). 18. A drive circuit as claimed in claim 17, wherein the switch arrangement comprises a charge switch (Q1) operable to close so as to activate the charging phase. 19. A drive circuit as claimed in claim 17, wherein the switch arrangement comprises a discharge switch (Q2) operable to close so as to activate the discharging phase. 20. A drive circuit as claimed in claim 19, wherein the connection of the drive circuit to the ground potential (VGND) is connected to the discharge switch (Q2). 21. A drive circuit as claimed in claim 16, further comprising a power supply and a regeneration switch (RSQ) operable at the end of the charging phase to transfer charge from the power supply to the first charge storage device (C1), before a subsequent discharging phase. 22. A drive circuit as claimed in claim 13, further comprising a selector switch (SQ1, SQ2) operable to select the fuel injector into the drive circuit and to deselect the fuel injector from the drive circuit. 23. A drive circuit for an injector arrangement comprising a fuel injector, the drive circuit comprising: i) a first charge storage device (C1) for operative connection with the fuel injector during a charging phase so as to cause a charge current to flow therethrough; ii) a second charge storage device (C2) for operative connection with the fuel injector during a discharge phase so as to permit a discharge current to flow therethrough; iii) a switch arrangement (Q1, Q2) for operably controlling the connection of the fuel injector to the first charge storage device (C1) or the second charge storage device (C2); and iv) a diagnostic tool (RH, RL; RF) operable to provide a signal on detection of a fault. 24. A drive circuit as claimed in claim 23, further comprising a selector switch arrangement (SQ1, SQ2) operable to select the fuel injector into the drive circuit and to deselect the fuel injector from the drive circuit. 25. A drive circuit as claimed in claim 24, wherein the diagnostic tool (RH, RL) is operable to: sense a measured voltage (VBIAS) between the injector and a known voltage level (VBAT, VGND) when the injector is deselected from the drive circuit; and provide a short circuit fault signal on sensing of a measured voltage (VBIAS) that differs from a first predicted voltage (VPinjN, VBcalc). 26. A drive circuit as claimed in claim 24, wherein the diagnostic tool (RH, RL) is operable to: sense a measured voltage (VBIAS) between the injector and the known voltage level (VBAT, VGND) when the injector is selected in the drive circuit; and provide an open circuit fault signal on sensing of a measured voltage (VBIAS) that differs from a second predicted voltage (VPinjN, VBcalc). 27. A drive circuit for an injector arrangement comprising a fuel injector, the drive circuit comprising: i) a first charge storage device (C1) for operative connection with the fuel injector during a charging phase so as to cause a charge current to flow therethrough; ii) a second charge storage device (C2) for operative connection with the fuel injector during a discharge phase so as to permit a discharge current to flow therethrough; iii) a switch arrangement (Q1, Q2) for operably controlling the connection of the fuel injector to the first charge storage device (C1) or the second charge storage device (C2); iv) a selector switch arrangement (SQ1, SQ2) operable to select the fuel injector into the drive circuit and to deselect the fuel injector from the drive circuit; and v) a diagnostic tool (RH, RL; RF) operable to: a) sense a measured voltage (VBIAS) between the injector and a known voltage level (VBAT, VGND) when the injector is deselected from the drive circuit; and b) provide a short circuit fault signal on sensing of a measured voltage (VBIAS) that differs from a first predicted voltage (VPinjN, VBcalc). 28. A drive circuit or an injector arrangement comprising a fuel injector, the drive circuit comprising: a selector switch arrangement (SQ1, SQ2) operable to select the fuel injector into the drive circuit and to deselect the fuel injector from the drive circuit; and a diagnostic tool (RH, RL) operable to: a) sense a measured voltage (VBIAS) between the injector and a known voltage level (VBAT, VGND) when the injector is deselected from the drive circuit; and b) provide a short circuit fault signal on sensing of a measured voltage (VBIAS) that differs from a first predicted voltage (VPinjN, VBcalc). 29. A drive circuit as claimed in claim 28, wherein the diagnostic tool (RH, RL) is further operable to: c) sense a measured voltage (VBIAS) between the injector and the known voltage level (VBAT, VGND) when the injector is selected in the drive circuit; and d) provide an open circuit fault signal on sensing of a measured voltage (VBIAS) that differs from a second predicted voltage (VPinjN, VBcalc). 30. An injector bank for an automotive engine, the injector bank comprising a fuel injector and a drive circuit as claimed in claim 28, wherein the fuel injector is operable by the drive circuit. 31. An engine control module for controlling the operation of an engine, the engine comprising a microprocessor for controlling the operation of the engine, a memory for recording data, and a drive circuit as claimed in claim 28, wherein the drive circuit is controllable by the microprocessor. 32. A method of detecting faults in a drive circuit for an injector arrangement comprising a fuel injector, the method comprising: a) sensing a measured voltage (VBIAS) between the injector and a known voltage level (VBAT, VGND), the measured voltage (VBIAS) being biased with respect to the known voltage (VBAT, VGND) to a predicted voltage (VPinjN, VBcalc) unless the drive circuit has a fault; and b) providing a fault signal on sensing of a measured voltage (VBIAS) that differs from the predicted voltage (VPinjN, VBcalc). 33. A method as claimed in claim 32, wherein the method further comprises operating selector a switch arrangement (SQ1, SQ2) to select the fuel injector into the drive circuit and to deselect the fuel injector from the drive circuit. 34. A method as claimed in claim 32, further comprising: i) sensing a detected current (Idect) through a connection of the drive circuit (20a) to the ground potential (VGND); and ii) providing a signal when the detected current (Idect) is at variance from a threshold current (Itrip). 35. A method as claimed in claim 32, the injector arrangement comprising more than one fuel injector, wherein the method comprises selecting each fuel injector in turn. 36. A method of detecting faults in a drive circuit for an injector arrangement comprising a fuel injector, the method comprising: a) sensing a detected current (Idect) through a connection of the drive circuit(20a) to the ground potential (VGND); and b) providing a signal when the detected current (Idect) is at variance from a threshold current (Itrip). 37. A method as claimed in claim 36, comprising providing the signal when the detected current (Idect) is greater than the threshold current (Itrip). 38. A method as claimed in claim 36, the drive circuit further comprising a switch arrangement in which a charge switch (Q1) is operable to activate a charging phase, wherein the method further comprises operating the charge switch (Q1) prior to detection of a fault associated with the drive circuit. 39. A method as claimed in claim 36, the switch arrangement comprising a discharge switch (Q2) operable to activate the discharge phase, wherein the method further comprises operating the discharge switch (Q2) prior to detection of a fault associated with the drive circuit. 40. A method as claimed in claim 36, the drive circuit further comprising a power supply and a regeneration switch (RSQ) for operably transferring charge from the power supply to a first charge storage device (C1), wherein the method further comprises operating the regeneration switch (RSQ) prior to detection of a fault. 41. A method as claimed in claim 36, the drive circuit further comprising a selector switch arrangement (SQ1, SQ2) for selecting the fuel injector into the drive circuit and for deselecting the fuel injector from the drive circuit, the method further comprising operating the selector switch arrangement (SQ1, SQ2) prior to detection of a fault. 42. A method of detecting faults in a drive circuit for an injector arrangement comprising a fuel injector, the method comprising: a) sensing a measured voltage (VBIAS) between the injector and a known voltage level (VBAT, VGND) when the injector is deselected from the drive circuit; and b) providing a short circuit fault signal on sensing of a measured voltage (VBIAS) that differs from a first predicted voltage (VPinjN, VBcalc). 43. A method as claimed in claim 42, further comprising c) sensing a measured voltage (VBIAS) between the injector and the known voltage level (VBAT, VGND) when the injector is selected in the drive circuit; and d) providing an open circuit fault signal on sensing of a measured voltage (VBIAS) that differs from a second predicted voltage (VPinjN, VBcalc). 44. A computer program product comprising at least one computer program software portion which, when executed in an executing environment, is operable to implement one or more of the steps of the method as claimed in claim 42. 45. A data storage medium having the or each computer software portion of claim 44. 46. A microcomputer provided with a data storage medium as claimed in claim 45.
|
<SOH> BACKGROUND ART <EOH>Automotive vehicle engines are generally equipped with fuel injectors for injecting fuel (e.g., gasoline or diesel fuel) into the individual cylinders or intake manifold of the engine. The engine fuel injectors are coupled to a fuel rail which contains high pressure fuel that is delivered by way of a fuel delivery system. In diesel engines, conventional fuel injectors typically employ a valve that is actuated to open and to close in order to control the amount of fluid fuel metered from the fuel rail and injected into the corresponding engine cylinder or intake manifold. One type of fuel injector that offers precise metering of fuel is the piezoelectric fuel injector. Piezoelectric fuel injectors employ piezoelectric actuators made of a stack of piezoelectric elements arranged mechanically in series for opening and for closing an injection valve to meter fuel injected into the engine. Piezoelectric fuel injectors are well known for use in automotive engines. The metering of fuel with a piezoelectric fuel injector is generally achieved by controlling the electrical voltage potential applied to the piezoelectric elements to vary the amount of expansion and contraction of the piezoelectric elements. The amount of expansion and contraction of the piezoelectric elements varies the travel distance of a valve piston and, thus, the amount of fuel that is passed through the fuel injector. Piezoelectric fuel injectors offer the ability to meter precisely a small amount of fuel. Typically, the fuel injectors are grouped together in banks of one or more injectors. As described in EP1400676, each bank of injectors has its own drive circuit for controlling operation of the injectors. The circuitry includes a power supply, such as a transformer, which steps-up the voltage V S generated by the power supply, i.e. from 12 Volts to a higher voltage, and storage capacitors for storing charge and, thus, energy. The higher voltage is applied across the storage capacitors which are used to power the charging and discharging of the piezoelectric fuel injectors for each injection event. Drive circuits have also been developed, as described in WO 2005/028836A1, which do not require a dedicated power supply, such as a transformer. The use of these drive circuits enables the voltage applied across the storage capacitors, and thus the piezoelectric fuel injectors, to be controlled dynamically. This is achieved by using two storage capacitors which are alternately connected to an injector arrangement. One of the storage capacitors is connected to the injector arrangement during a discharge phase when a discharge current flows through the injector arrangement, initiating an injection event. The other storage capacitor is connected to the injector arrangement during a charging phase, terminating the injection event. A regeneration switch is used at the end of the charging phase, before a later discharge phase, to replenish the storage capacitors. Like any circuit, faults may occur in a drive circuit. In safety critical systems, such as diesel engine fuel injection systems, a fault in the drive circuit may lead to a failure of the injection system, which could consequentially result in a catastrophic failure of the engine. A robust diagnostic system is therefore required to detect critical failure modes of piezoelectric actuators, and of the associated drive circuits, particularly whilst the drive circuit is in use. An aim of the invention is therefore to provide a diagnostic tool that is capable of detecting critical failure modes, or fault response characteristics, of an injector arrangement, and the associated drive circuits, and a method of operating the diagnostic tool.
|
TECHNICAL FIELD The present invention relates to a drive circuit for an injector arrangement having a diagnostic means for detecting a fault, and a diagnostic method for the drive circuit of an injector arrangement. The drive circuit is especially, although not exclusively, for an injector arrangement in an internal combustion engine, the injector arrangement including an injector of the type having a piezoelectric actuator for controlling injector valve needle movement. BACKGROUND ART Automotive vehicle engines are generally equipped with fuel injectors for injecting fuel (e.g., gasoline or diesel fuel) into the individual cylinders or intake manifold of the engine. The engine fuel injectors are coupled to a fuel rail which contains high pressure fuel that is delivered by way of a fuel delivery system. In diesel engines, conventional fuel injectors typically employ a valve that is actuated to open and to close in order to control the amount of fluid fuel metered from the fuel rail and injected into the corresponding engine cylinder or intake manifold. One type of fuel injector that offers precise metering of fuel is the piezoelectric fuel injector. Piezoelectric fuel injectors employ piezoelectric actuators made of a stack of piezoelectric elements arranged mechanically in series for opening and for closing an injection valve to meter fuel injected into the engine. Piezoelectric fuel injectors are well known for use in automotive engines. The metering of fuel with a piezoelectric fuel injector is generally achieved by controlling the electrical voltage potential applied to the piezoelectric elements to vary the amount of expansion and contraction of the piezoelectric elements. The amount of expansion and contraction of the piezoelectric elements varies the travel distance of a valve piston and, thus, the amount of fuel that is passed through the fuel injector. Piezoelectric fuel injectors offer the ability to meter precisely a small amount of fuel. Typically, the fuel injectors are grouped together in banks of one or more injectors. As described in EP1400676, each bank of injectors has its own drive circuit for controlling operation of the injectors. The circuitry includes a power supply, such as a transformer, which steps-up the voltage VS generated by the power supply, i.e. from 12 Volts to a higher voltage, and storage capacitors for storing charge and, thus, energy. The higher voltage is applied across the storage capacitors which are used to power the charging and discharging of the piezoelectric fuel injectors for each injection event. Drive circuits have also been developed, as described in WO 2005/028836A1, which do not require a dedicated power supply, such as a transformer. The use of these drive circuits enables the voltage applied across the storage capacitors, and thus the piezoelectric fuel injectors, to be controlled dynamically. This is achieved by using two storage capacitors which are alternately connected to an injector arrangement. One of the storage capacitors is connected to the injector arrangement during a discharge phase when a discharge current flows through the injector arrangement, initiating an injection event. The other storage capacitor is connected to the injector arrangement during a charging phase, terminating the injection event. A regeneration switch is used at the end of the charging phase, before a later discharge phase, to replenish the storage capacitors. Like any circuit, faults may occur in a drive circuit. In safety critical systems, such as diesel engine fuel injection systems, a fault in the drive circuit may lead to a failure of the injection system, which could consequentially result in a catastrophic failure of the engine. A robust diagnostic system is therefore required to detect critical failure modes of piezoelectric actuators, and of the associated drive circuits, particularly whilst the drive circuit is in use. An aim of the invention is therefore to provide a diagnostic tool that is capable of detecting critical failure modes, or fault response characteristics, of an injector arrangement, and the associated drive circuits, and a method of operating the diagnostic tool. STATEMENTS OF THE INVENTION According to a first aspect of the invention there is provided: a drive circuit for an injector arrangement comprising a fuel injector, the drive circuit comprising diagnostic means operable: a) to sense a measured voltage between the injector and a known voltage level, the measured voltage being biased with respect to the known voltage to a predicted voltage unless the drive circuit has a fault; and b) to provide a fault signal on sensing of a measured voltage that differs from the predicted voltage. An advantage is that the drive circuit comprises a robust diagnostic system that is capable of detecting critical failure modes of the drive circuit, preventing failure of the drive circuit and the injector arrangement to which the drive circuit is connected. The diagnostic means uses a voltage associated with the fuel injector in order to detect the fault and to identify the type of fault. The drive circuit may further comprise selector switch means operable to select the fuel injector into the drive circuit and to deselect the fuel injector from the drive circuit. Advantageously, The fuel injector may also be connected to and removed from the drive circuit by operation of the selector switch means. The predicted voltage may be the voltage between the fuel injector and the known voltage level when the injector is deselected from the drive circuit. Beneficially, the diagnostic means is capable of detecting a short circuit fault associated with the fuel injector. Thus, it is possible to detect the short circuit without having to select the injector (and hence connect it to the drive circuit), restricting the damage caused to it and the rest of the drive circuit by a short circuit fault. The diagnostic means is, preferably, capable of detecting an open circuit fault associated with the fuel injector. In this case, the predicted voltage may be substantially the sum of the known voltage and a voltage across the fuel injector when the fuel injector is selected in the drive circuit. The selector switch means may be operable to enable detection of a fault. Preferably, the selector switch means is operable prior to detection of the fault. Beneficially, open circuit faults associated with the fuel injector can be detected when voltage is being sensed. The signal may be provided if the measured voltage is outside a tolerance voltage of the predicted voltage. This provides the benefit that the diagnostic means only provides a signal where the fuel injector is unable to function satisfactorily. The measured voltage may be sensed across part of a potential divider connected to the injector and the known voltage. The potential divider may be connected to a high voltage rail. The injector may have a high side and the diagnostic means may be operable to sense a measured voltage between the high side of the fuel injector and the known voltage. The low side of the injector may be connected a low voltage rail. The low voltage rail may, in use, be at a lower voltage than the high voltage rail. The divider may comprise at least two resistive elements. The resistive elements may each have a high resistance. The diagnostic means may be in a connection of the drive circuit to a ground potential. The diagnostic means may be operable to sense a detected current. The diagnostic means may also be operable by sensing a current to provide a signal on detection of a fault. Preferably, the signal is provided when the detected current is at variance from a threshold current. Advantageously, the diagnostic means uses a current associated with the fuel injector, in order to detect a fault. The type of short circuit fault can be determined by the sensing current that is used to determine the presence of a fault. The signal may be provided when the detected current is greater than the threshold current. The diagnostic means may comprise a resistive element through which the detected current is sensed. The connection of the drive circuit to the ground potential may be connected to charge storage means. The connection of the drive circuit to the ground potential may be connected to a discharge switch. The drive circuit may comprise first charge storage means (e.g. comprising a capacitor) for operative connection with the fuel injector during a charging phase so as to cause a charge current to flow therethrough. The drive circuit may comprise second charge storage means (e.g. comprising a capacitor) for operative connection with the fuel injector during a discharge phase so as to permit a discharge current to flow therethrough. The drive circuit may comprise switch means for operably controlling the connection of the fuel injector to the first charge storage means or the second charge storage means. The discharging phase may initiate an injection event, and the charging phase may terminate the injection event, or vice versa. In another embodiment there may be only one charge storage means. The switch means may comprise a charge switch operable to close so as to activate the charging phase. Advantageously, when sensing current to detect a fault, high side short circuit faults can be detected. Also, where there is no or negligible charge on the fuel injector, low side short circuit faults can be detected. The switch means may comprise a discharge switch operable to close so as to activate the discharge phase. Preferably, when sensing current to detect a fault, a low side to ground potential short circuit fault can be detected at start up if there is residual charge on the fuel injector. The drive circuit may comprise a power supply means. The drive circuit may comprise regeneration switch means. Operating the regeneration switch provides an advantage of enabling detection of a fault. Preferably, the regeneration switch is operated prior to the detection of the fault. The regeneration switch means may be operable at the end of the charging phase to transfer charge. The operation of the regeneration switch means may transfer charge from the power supply means to the first charge storage means, before a subsequent discharging phase. In one mode of operation, the drive circuit may be deliberately tripped at start-up when sensing current to detect a fault in order to rule out high side and low side to ground short circuit faults. Note that in this mode of operation, low side to ground short circuit faults may only be detected by using the regeneration switch means if there is no charge, if any, on the fuel injector. In another mode of operation, the regeneration switch is operated during normal running conditions to detect a fault. Charge may be transferred from the first to the second charge storage means via an energy storage device. The drive circuit is particularly suitable for use with fuel injectors comprising a piezoelectric actuator, but other fuel injector types are also envisaged (e.g. solenoid actuated). According to a second aspect of the invention there is provided a drive circuit for an injector arrangement comprising a fuel injector, the drive circuit comprising diagnostic means in a connection of the drive circuit to a ground potential, the diagnostic means being operable: a) to sense a detected current; and b) to provide a signal on detection of a fault, wherein the signal is provided when the detected current is at variance from a threshold current. This aspect of the invention provides a robust diagnostic system to detect critical failure modes of the drive circuit, preventing failure of the drive circuit and the injector arrangement to which it is connected. The diagnostic means uses a current associated with the fuel injector, in order to detect a fault. The type of short circuit fault can be determined from the sensed current. The signal may be provided when the detected current is greater than the threshold current. The connection of the drive circuit to the ground potential may be connected to charge storage means. The charge storage means may comprise first charge storage means for operative connection with the fuel injector during a charging phase so as to cause a charge current to flow therethrough. Additionally, the charge storage means may comprise second charge storage means for operative connection with the fuel injection during a discharge phase so as to permit a discharge current to flow therethrough. The connection of the drive circuit to the ground potential may be connected to switch means for operably controlling the connection of the fuel injector to the first charge storage means or the second charge storage means. The switch means typically includes one or more of a charge switch operable to close so as to activate the charging phase and a discharge switch operable to close so as to activate the discharging phase. The connection of the drive circuit to the ground potential may be connected to the discharge switch. The drive circuit may comprise a power supply means. The drive circuit may comprise regeneration switch means. The regeneration switch means may be operable at the end of the charging phase to transfer charge from the power supply means to the first charge storage means, before a subsequent discharging phase. In another embodiment, only one charge storage means is provided. The drive circuit may comprise selector switch means. It may be beneficial to have the selector switch means operable to select the fuel injector into the drive circuit so as to enable a high side to ground potential short circuit fault to be detected. Accordingly, the second aspect of the invention may take any of the optional features of the first aspect of the invention. According to a third aspect of the invention there is provided a drive circuit for an injector arrangement comprising a fuel injector, the drive circuit comprising: i) first charge storage means for operative connection with the fuel injector during a charging phase so as to cause a charge current to flow therethrough; ii) second charge storage means for operative connection with the fuel injector during a discharge phase so as to permit a discharge current to flow therethrough; iii) switch means for operably controlling the connection of the fuel injector to the first charge storage means or the second charge storage means; and diagnostic means operable to provide a signal on detection of a fault. Preferably, the switch means is operable prior to detection of the fault. Accordingly, the third aspect of the invention may take any of the optional features of the first or second aspects of the invention. According to a fourth aspect of the invention there is provided an injector bank for an automotive engine, the bank comprising a fuel injector and a drive circuit according to any of the first, second or third aspects of the invention, wherein the fuel injector is operable by the drive circuit. According to a fifth aspect of the invention there is provided an engine control module for controlling the operation of an engine, the engine comprising a microprocessor for controlling the operation of the engine, a memory for recording data, and a drive circuit according to any of the first, second or third aspects of the invention, wherein the drive circuit is controllable by the microprocessor. According to a sixth aspect of the invention there is provided a method of detecting faults in a drive circuit for an injector arrangement comprising a fuel injector, the method comprising: a) sensing a measured voltage between the injector and a known voltage level, the measured voltage being biased with respect to the known voltage to a predicted voltage unless the drive circuit has a fault; and b) providing a fault signal on sensing of a measured voltage that differs from the predicted voltage. The method may comprise operating selector switch means to select the fuel injector into the drive circuit. Selector switch means may be operated to deselect the fuel injector from the drive circuit. Preferably, the selector switch means is operated to enable detection of a fault. Advantageously, the selector switch means may be operated prior to detection of the fault. On deselecting the fuel injector from the drive circuit the predicted voltage may be the voltage between the fuel injector and the known voltage level. On selecting the fuel injector in the drive circuit the predicted voltage may be substantially the sum of the known voltage and a voltage across the fuel injector. In one embodiment, the method may comprise operating the selector switch at start-up of the drive circuit. In another embodiment, the selector switch may be operated during operation of the drive circuit. The method may comprise providing the signal if the measured voltage is outside a tolerance voltage of the predicted voltage. The detected current may be sensed through a connection of the drive circuit to the ground potential. The method further comprises providing a signal when the detected current is at variance from a threshold current. Advantageously, the signal is provided as an indication when the detected current is greater than the threshold current. The detected current is preferably sensed through a resistive element. The connection of the drive circuit to the ground potential may be connected to charge storage means. The connection of the drive circuit to the ground potential may be connected to a discharge switch. In a preferred embodiment, the switch means may comprise a charge switch for operably activating a charging phase. The method may comprise operating the charge switch to enable the detection of a fault associated with the drive circuit. Preferably, the charge switch is operated prior to detection of the fault. For example, in one embodiment, the method may comprise detecting a fault if substantially no charge is present on the injector. In another embodiment, the charge switch may be operated for a predetermined period of time before operating the diagnostic means in order to detect a fault. However, the charge switch is preferably closed so as to activate the charging phase. In a preferred embodiment, the switch means may comprise a discharge switch for operably activating the discharge phase. The method may comprise closing the discharge switch so as to activate the discharge phase. On closing the discharge switch detection of a fault associated with the drive circuit may be enabled. Preferably, the discharge switch is operated prior to detection of the fault. If any charge is substantially present on the fuel injector, the method may comprise operating the discharge switch for a predetermined period of time to enable a fault to be detected. The drive circuit may comprise a power supply means. It may also comprise regeneration switch means for operably transferring charge from the power supply means to the first charge storage means. The method may comprise operating the regeneration switch means to enable detection of a fault. Preferably, the regeneration switch means is operable prior to detection of the fault. The method may comprise operating the regeneration switch means when there is substantially no charge on the fuel injector. The method may comprise operating the regeneration switch means at the end of the charging phase so as to transfer charge from the power supply means to the first charge storage means. The transfer of charge may occur before a subsequent discharging phase. Transferring of charge from the power supply means to the first charge storage means may be via an energy storage device. The injector arrangement may comprise more than one fuel injector, in which case the method may comprise selecting each fuel injector in turn. The drive circuit may be one of a plurality of drive circuits, each of which is associated with a different fuel injector. The method may comprise operating each drive circuit in turn in order to detect a fault. All activity may be stopped on the fuel injector associated with the drive circuit before operating the drive circuit in order to detect a fault. For example, the method may comprise opening all switches of the drive circuit before operating the drive circuit in order to detect a fault. If a fault of the drive circuit is not detected, a fuel injector is then enabled for operation. According to a seventh aspect of the invention there is provided a method of detecting faults in a drive circuit for an injector arrangement comprising a fuel injector, the method comprising: a) sensing a detected current through a connection of the drive circuit to the ground potential; and b) providing a signal when the detected current is at variance from a threshold current. Preferably, the signal is provided to indicate a fault when the detected current is greater than the threshold current. The switch means may comprise a charge switch for operably activating a charging phase. In one embodiment, operation of the charge switch enables the detection of a fault associated with the drive circuit. Operation of the charge switch is, preferably, prior to detection of the fault. The switch means may comprise a discharge switch for operably activating the discharge phase. Operation of the discharge switch may enable the detection of a fault associated with the drive circuit. Preferably, operation of the discharge switch is prior to detection of the fault. The drive circuit may comprise a power supply means. The drive circuit may comprise regeneration switch means for operably transferring charge from the power supply means to the first charge storage means. Preferably, the method comprises operating the regeneration switch means to enable detection of a fault. Operation of the regeneration switch means may be prior to detection of the fault. The drive circuit may comprise selector switch means for selecting the fuel injector into the drive circuit and for deselecting the fuel injector from the drive circuit. The method may comprise operating the selector switch means to enable detection of a fault. Preferably, operation of the selector switch means is prior to the detection of the fault. Accordingly, the seventh aspect of the invention may take any of the steps of the method according to the sixth aspect of the invention. According to an eighth aspect of the invention there is provided a method of operating the drive circuit according to the third aspect of the invention. The eighth aspect of the invention may optionally take any of the steps of the method according to the sixth or seventh aspects of the invention. According to a ninth aspect of the invention there is provided a computer program product comprising at least one computer program software portion which, when executed in an executing environment, is operable to implement one or more of the steps of the method of the sixth, seventh or eighth aspects of the invention. According to a tenth aspect of the invention there is provided a data storage medium having the or each computer software portion according to the ninth aspect of the invention. According to an eleventh aspect of the invention there is provided a microcomputer provided with a data storage medium according to the aspect of the invention. According to a twelfth aspect of the invention there is provided a method of detecting faults in a drive circuit for an injector arrangement comprising a fuel injector, the method comprising: a) sensing a measured voltage between the injector and a known voltage level when the injector is deselected from the drive circuit; and b) providing a short circuit fault signal on sensing of a measured voltage that differs from a first predicted voltage. According to a thirteenth aspect of the invention, there is provided a drive circuit for an injector arrangement comprising a fuel injector, the drive circuit comprising: i) a first charge storage device for operative connection with the fuel injector during a charging phase so as to cause a charge current to flow therethrough; ii) a second charge storage device for operative connection with the fuel injector during a discharge phase so as to permit a discharge current to flow therethrough; iii) a switch arrangement for operably controlling the connection of the fuel injector to the first charge storage device or the second charge storage device; iv) a selector switch arrangement operable to select the fuel injector into the drive circuit and to deselect the fuel injector from the drive circuit; and v) a diagnostic tool operable to: a) sense a measured voltage between the injector and a known voltage level when the injector is deselected from the drive circuit; and b) provide a short circuit fault signal on sensing of a measured voltage that differs from a first predicted voltage. According to a fourteenth of the invention, there is provided a drive circuit for an injector arrangement comprising a fuel injector, the drive circuit comprising: a selector switch arrangement operable to select the fuel injector into the drive circuit and to deselect the fuel injector from the drive circuit; and a diagnostic tool operable to: a) sense a measured voltage between the injector and a known voltage level when the injector is deselected from the drive circuit; and b) provide a short circuit fault signal on sensing of a measured voltage that differs from a first predicted voltage. The terms close and activate are interchangeable when used in connection with a switch, and are intended to include the actuation of any suitable switching means to create an electrical connection across the switch. Conversely, the terms open and deactivate, when used in connection with a switch, are interchangeable, and are intended to include the actuation of any suitable switching means to break an electrical connection across the switch. FIGURES Preferred embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: FIG. 1 is a block diagram illustrating a drive circuit for controlling a piezoelectric fuel injector arrangement in an engine; FIG. 2 is a circuit diagram illustrating the piezoelectric drive circuit in FIG. 1; FIG. 3 is a circuit diagram as shown in FIG. 2, having a first diagnostic tool (a resistive bias network) according to a first embodiment of the present invention and a second diagnostic tool (a fault trip circuit) according to a second embodiment of the present invention; FIG. 4 is the circuit diagram of FIG. 3, configured to detect an injector with an open circuit fault using the resistive bias network; FIG. 5 is a schematic representation of a voltage waveform across a bank of injectors, illustrating the timing of the use, in an injection cycle, of the resistive bias network shown in FIG. 3; FIG. 6 is a flow diagram of a diagnostic method using the resistive bias network shown in FIG. 3 whilst the drive circuit is in operation; FIG. 7 is a flow diagram of a diagnostic method of using the resistive bias network shown in FIG. 3 when the injector arrangement is at start-up; FIG. 8 is a circuit diagram illustrating a drive circuit shown in FIG. 3 with the fault trip circuit having a discharge switch closed, and having residual charge on a fuel injector, in order to detect a low side to ground potential short circuit fault; FIG. 9 is a circuit diagram illustrating the drive circuit shown in FIG. 3 with the fault trip circuit having an injector selector switch closed in order to detect a high side to ground potential short circuit fault; FIG. 10 is a circuit diagram illustrating the drive circuit shown in FIG. 3 with the fault trip circuit having a charge switch closed in order to detect a high side to ground potential short circuit fault; FIG. 11 is a circuit diagram illustrating the drive circuit shown in FIG. 3 with the fault trip circuit having the charge switch closed in order to detect a low side to ground potential short circuit fault; FIG. 12 is a circuit diagram illustrating the drive circuit shown in FIG. 3 with the fault trip circuit having a regeneration switch closed in order to detect a high side to ground potential short circuit fault; FIG. 13 is a circuit diagram illustrating the drive circuit shown in FIG. 3 with the fault trip circuit having a regeneration switch closed and having no or negligible charge on the injector, in order to detect a low side to ground potential short circuit fault; and FIG. 14 is a flow diagram of a diagnostic method of using the fault trip circuit shown in FIGS. 8 to 13, which is used when the injector arrangement is at start-up. DETAILED DESCRIPTION Referring to FIG. 1, an engine 8, such as an automotive vehicle engine, is generally shown having an injector arrangement comprising a first fuel injector 12a and a second fuel injector 12b. The fuel injectors 12a, 12b each have an injector valve 13 and a piezoelectric actuator 11. The piezoelectric actuator 11 is operable to cause the injector valve 13 to open and close to control the injection of fuel into an associated cylinder of the engine 8. The fuel injectors 12a, 12b may be employed in a diesel engine to inject diesel fuel into the engine 8, or they may be employed in a spark ignited internal combustion engine to inject combustible gasoline into the engine 8. The fuel injectors 12a, 12b form a first bank 10 of fuel injectors of the engine 8 and are controlled by means of a drive circuit 20a. The drive circuit 20a is arranged to monitor and control the injector high side voltages VI1HI, VI2HI and injector low side voltages VI1LO, VI2LO so as to control actuation of the first and second fuel injectors 12a, 12b respectively, to open and close the injectors. Voltages VI1HI and VI2HI represent the high side voltages of injectors 12a, 12b, respectively, and VI1LO, VI2LO represent the low side voltages of fuel injectors 12a, 12b, respectively. In practice, the engine 8 may be provided with two or more banks, each containing one or more fuel injectors and each bank having its own drive circuit 20b to 20N. Where possible, for reasons of clarity, the following description relates to only one of the banks. In the preferred embodiments of the invention described below, the fuel injectors 12a, 12b are of a negative-charge displacement type. The fuel injectors 12a, 12b are therefore opened to inject fuel into the engine cylinder during a discharge phase and closed to terminate injection of fuel during a charging phase. The engine 8 is controlled by an Engine Control Module (ECM) 14, of which the drive circuit 20a forms an integral part. The ECM 14 includes a microprocessor 16 and a memory 24 which are arranged to perform various routines to control the operation of the engine 8, including the control of the fuel injector arrangement. The ECM 14 is arranged to monitor engine speed and load. It also controls the amount of fuel supplied to the fuel injectors 12a, 12b and the timing of operation of the fuel injectors. The ECM 14 is connected to an engine battery (not shown) which has battery voltage VBAT of about 12 Volts. The ECM 14 generates the voltages required by other components of the engine 8 from the battery voltage VBAT. Further detail of the operation of the ECM 14 and its functionality in operating the engine 8, particularly the injection cycles of the injector arrangement, is described in detail in WO 2005/028836. Signals are transmitted between the microprocessor 16 and the drive circuit 20a and data, comprised in the signals received from the drive circuit 20a, is recorded on the memory 24. The drive circuit 20a operates in three main phases: a charging phase, a discharge phase and a regeneration phase. During the discharge phase, the drive circuit 20a operates to discharge one of the fuel injectors 12a, 12b to open the injector valve 13 to inject fuel. During the charging phase, the drive circuit 20a operates to charge the fuel injector 12a, 12b to close the injector valve 13 to terminate injection of fuel. During the regeneration phase, energy in the form of electric charge is replenished to a first storage capacitor C1 and a second storage capacitor C2 (not shown in FIG. 1), for use in subsequent injection cycles, so that a dedicated power supply is not required. Each of these phases of operation will be described in further detail below. Referring also to FIG. 2, the drive circuit 20a comprises a first voltage rail V0 and a second voltage rail V1. The first voltage rail V0 is at a higher voltage than the second voltage rail V1. The drive circuit 20a also includes a half-H-bridge circuit having a middle current path 32 which serves as a bidirectional current path. The middle current path 32 has an inductor L1 coupled in series with a bank 10 of fuel injectors 12a, 12b. The fuel injectors 12a, 12b and their associated switching circuitry are connected in parallel with each other. Each fuel injector 12a, 12b has the electrical characteristics of a capacitor, with its piezoelectric actuator 11 being chargeable to hold voltage which is the potential difference between a low side (+) terminal and a high side (−) terminal of the piezoelectric actuator 11. The drive circuit 20a further comprises the first storage capacitor C1, and the second storage capacitor C2. Each of the storage capacitors C1, C2 has a positive and a negative terminal. Each storage capacitor C1, C2 has a high side and a low side; the high side is on the positive terminal of the capacitor and the low side is on the negative terminal. The first storage capacitor C1 is connected between the first voltage rail V0 and the second voltage rail V1. The second storage capacitor C2 is connected between the second voltage rail V1 and the ground potential VGND. In addition, the drive circuit 20a has a voltage source VS, or power supply, 22 supplied by the ECU 14. The voltage source VS is connected between the second voltage rail V1 and the ground potential VGND, and is thus arranged to supply energy to the second storage capacitor C2. Typically the voltage source VS is between 50 and 60 Volts. The drive circuit 20a does not have a dedicated power supply to supply charge to the first and second storage capacitors C1, C2. However the second storage capacitor C2 is connected to the power supply 22, but the first storage capacitor C1 relies on regeneration of charge to it during the regeneration phase. In the drive circuit 20a there is a charge switch Q1 and a discharge switch Q2 for controlling, respectively, the charging and discharging operations of the first and second fuel injectors 12a, 12b. The charge and the discharge switches Q1, Q2 are operable by the microprocessor 16. Each of the charge and the discharge switches Q1, Q2, when closed, allows for unidirectional current flow through the switch and, when open, prevents current flow. The charge switch Q1, has a first recirculation diode RD1 connected across it. Likewise, the discharge switch Q2 has a second recirculation diode RD2 connected across it. These recirculation diodes RD1, RD2 permit recirculation current to return charge to the first storage capacitor C1 and the second storage capacitor C2, respectively, during an energy recirculation phase of operation of the drive circuit 20a, in which energy is recovered from at least one of the fuel injectors 12a, 12b. The first fuel injector 12a is connected in series with an associated first selector switch SQ1, and the second fuel injector 12b is connected in series with an associated second selector switch SQ2. Each of the selector switches SQ1, SQ2 is operable by the microprocessor 16. A first diode D1 is connected in parallel with the first selector switch SQ1, and a second diode D2 is connected in parallel with the second selector switch SQ2. When the first selector switch SQ1 (associated with the first fuel injector 12a) is activated, for example, a current IDISCHARGE is permitted to flow in a discharge direction through the selected fuel injector 12a. The first and second diodes D1, D2 each allow a current ICHARGE to flow in a charge direction during the charging phase of operation of the circuit, across the first and the second fuel injectors 12a, 12b, respectively. A regeneration switch circuitry is included in the drive circuit 20a in parallel with the injectors 12a, 12b to implement the regeneration phase. The regeneration switch circuitry serves to connect the second storage capacitor C2 to the inductor L1. The regeneration switch circuitry comprises a regeneration switch RSQ which is operable by the microprocessor 16. A first regeneration switch diode RSD1 is connected in parallel with the regeneration switch RSQ. A second regeneration switch diode RSD2 is coupled in series to the first regeneration switch diode RSD1 and the regeneration switch RSQ, and acts as a protection diode. The first and second regeneration switch diodes RSD1, RSD2 are opposed to each other such that current will not flow through the regeneration switch circuitry unless the regeneration switch RSQ is closed and current is flowing from the second voltage rail V1. Current, thus, cannot pass through the regeneration switch circuitry during the charging phase. The middle current path 32 includes a current sensing and control means 34 that arranged to communicate with the microprocessor 16. The current sensing and control means 34 is arranged to sense the current in the middle current path 32, to compare the sensed current with a predetermined current threshold, and to generate an output signal when the sensed current is substantially equal to the predetermined current threshold. A voltage sensing means VSENSE (not shown) is also provided to sense the voltage across the fuel injector 12a, 12b selected for injection. The voltage sensing means is also used to sense the voltages VC1, VC2 across the first and second storage capacitors C1, C2, and the power supply 22. The regeneration phase is terminated when sensed voltage levels VC1, VC2 across the first and second storage capacitors C1, C2 are substantially the same as predetermined voltage levels. The drive circuit 20a also includes control logic 30 for receiving the output of the current sensing and control means 34, the sensed voltage, VSENSE, from the positive terminal (+) of the actuators 11 of the fuel injectors 12a and 12b, and the various output signals from the microprocessor 16 and its memory 24. The control logic 30 includes software executable by the microprocessor 16 for processing the various inputs so as to generate control signals for each of the charge and the discharge switches Q1, Q2, the first and second selector switches SQ1, SQ2, and the regeneration switch RSQ. During operation of the drive circuit 20a, a drive pulse (or voltage waveform) is applied to the piezoelectric actuator 11 of each fuel injector 12a and 12b, for example the first fuel injector 12a. The drive pulse varies between the charging voltage, VCHARGE, and the discharging voltage, VDISCHARGE. When the first fuel injector 12a is in a non-injecting state, prior to injection, the drive pulse is at VCHARGE so that a relatively high voltage is applied to the piezoelectric actuator 11. Typically, VCHARGE is around 200 to 300 V. When it is required to initiate an injection event, the drive pulse is reduced to VDISCHARGE, which is typically around −100 V. To terminate injection, the voltage of the drive pulse is increased to its charging voltage level, VCHARGE, once again. In general, in operating a selected fuel injector (e.g. the first fuel injector 12a) on a bank 10, the associated drive circuit 20a is operated in the following manner. Firstly, the discharge switch Q2 and the first selector switch SQ1 of the first fuel injector 12a are closed. During the discharge phase that follows, the discharge switch Q2 is automatically opened and closed until the voltage across the selected fuel injector 12a is reduced to the appropriate voltage discharge level (i.e. VDISCHARGE,) to initiate injection. After a predetermined time when injection is required, closing of the fuel injector 12a is achieved by closing the charge switch Q1, causing a charging current to flow through the first and second fuel injectors 12a and 12b. During the subsequent charging phase, the charge switch Q1 is continually opened and closed until the appropriate charge voltage level is achieved (i.e. VCHARGE). During the regeneration phase, the regeneration switch RSQ is activated, and the discharge switch Q2 is periodically opened and closed under the control of a signal emitted by the microprocessor 16 until the energy on the first storage capacitor C1 reaches a predetermined level. The operation of the drive circuit 20a during the regeneration phase will now be described in further detail. The regeneration phase follows the charging phase at the end of an injection event. During the regeneration phase, the regeneration switch RSQ (which has remained deactivated during the charging and discharge phases) is activated, and the discharge switch Q2 is opened, and closed, under the control of a modulated signal from the microprocessor 16, until the energy on the first storage capacitor C1 reaches a predetermined level. With the regeneration switch RSQ closed, while the discharge switch Q2 is closed, current is drawn from the power supply 22 and passes through the regeneration switch RSQ, through the second regeneration switch diode RSD2, through the inductor L1, through the discharge switch Q2, and across the second storage capacitor C2 such that the energy on the second storage capacitor C2 decreases. When the discharge switch Q2 is opened, current flows from the first storage capacitor C1, through the second regeneration switch diode RSD2, through the regeneration switch RSQ, through the current sensing and control means 34, through the inductor L1, and the first recirculation diode RD1 associated with the charge switch Q1, to the positive terminal of the first storage capacitor C1 such that the energy on the first storage capacitor C1 increases. Thus, during the regeneration phase the inductor L1 transfers energy from the second storage capacitor C2 to the first storage capacitor C1, and the power supply 22 maintains the voltage across C2. Thus, the regeneration phase is used to transfer the voltage VS of the power supply 22 to the second voltage rail V1 such that the voltage across the first storage capacitor C1 increases. Various modes of operation of the drive circuit 20a in the charging and discharge phases, and the regeneration phase, are described in detail in WO 2005/028836A1. Faults such as short circuits and open circuit faults associated with the fuel injectors 12a, 12b in the drive circuit 20a have detectable fault response characteristics. These fault response characteristics are critical failure modes of a drive circuit and its associated bank. Such a fault present in the drive circuit 20a may affect the performance of the injector arrangement and may be critical, ultimately, to the performance of the engine 8. Although the aforementioned drive circuit 20a and its associated injectors 12a, 12b have already been developed, a suitable diagnostic tool and a suitable diagnostic method to detect these fault response characteristics has been, until now, unknown. Referring to FIG. 3, the drive circuit 20a is provided with an integral diagnostic tool. For ease of reference all the features common to FIG. 2 have the same reference numerals in FIG. 3. The diagnostic tool provides a robust diagnostic system that is operated according to specific diagnostic methods to detect critical failure modes of the drive circuit 20a, and its associated piezoelectric fuel injectors 12a, 12b, thereby preventing complete failure of the drive circuit 20a and the fuel injectors 12a, 12b. The diagnostic tool may be embodied, in general, in two different forms, both of which are shown in FIG. 3. The first embodiment of the diagnostic tool is a resistive bias network comprising a first resistor RH and a second resistor RL. The first resistor RH is connected between the first voltage rail V0 and the high side of the fuel injectors 12a, 12b at a bias point PB that is connected to the inductor L1. The second resistor RL is also connected to the high side of the fuel injectors 12a, 12b, at the bias point PB, and to the ground potential VGND. The first and second resistors RL and RH each have a known resistance of a high order of magnitude. A volt sensor 25 is connected across the second resistor RL and provides an output to the microprocessor 16. The microprocessor 16 is arranged to operate the volt sensor 25 and receives signals from the volt sensor 25 indicative of a bias voltage across the second resistor RL. In the second embodiment of the diagnostic tool, referred to as a fault trip circuit, a fault trip resistor RF, in the connection of the drive circuit 20a to the ground potential VGND. A current sensor 27 is connected in series with the fault trip resistor RF in order to sense the current that passes through the fault trip resistor RF. The fault trip resistor RF is of very low resistance with an order of magnitude of milliohms. The microprocessor 16 is arranged to transmit control signals to the current sensor 27 and receives signals from the current sensor 27 indicative of the current flow through the fault trip resistor RF. Note that, because the fault trip resistor RF is in series with the ground potential VGND that is connected to all of the banks in an injector arrangement, only one fault trip resistor RF is required. Thus, in using the fault trip circuit, if a failure of the drive circuit 20a or the bank 10 is detected, it will only be possible in some circumstances to determine that there is a fault in the injector arrangement. It will not be possible to determine with which fuel injector 12a, 12b the fault is associated. Indeed, if the injector arrangement has more than one bank 10, it may not be possible in some circumstances to determine with which bank 10 the fault is associated. When a bank 10 and its associated drive circuit 20a are operating under normal running conditions, the charges on the piezoelectric actuators 11 of the associated fuel injectors 12a, 12b of the bank 10 are accurately predictable at any point during an injection cycle. Therefore, for faults in a drive circuit 20a that occur whilst the drive circuit 20a is in operation, the charges on the piezoelectric actuators 11 of the fuel injectors 12a, 12b are generally, known. However, at start-up the charges on the piezoelectric actuators 11 are not known. Therefore, it is necessary to test for faults at start up using a different method from that used when the bank 10 is in operation. The two embodiments of the diagnostic tool (i.e. the resistive bias network with its resistors RH, RL, and the fault trip circuit with its fault trip resistor RF) enable both types of fault to be detected, one being used whilst the drive circuit 20a and its associated bank 10 is in operation, and the other being used when the drive circuit 20a and the bank 10 are at start-up. Referring to the features of the resistive bias network in FIG. 3, with all the switches (Q1, Q2, SQ1, SQ2, and RSQ) open, and the piezoelectric actuators 11 of both injectors 12a, 12b fully charged, the detected voltage at the bias point PB relative to the ground potential VGND, across the second resistor RL, is equal to a measured bias voltage VBIAS. By knowing the resistance of the first resistor RH and the second resistor RL, and the voltage of the first voltage rail V0, a predetermined bias voltage VBcalc is calculated. If there are no faults in the drive circuit 20a or the fuel injectors 12a, 12b, the measured bias voltage VBIAS is substantially the same as the predetermined bias voltage VBcalc. If there is a short circuit fault associated with any of the fuel injectors 12a, 12b in the particular bank 10, the measured bias voltage VBIAS at the bias point PB will not be the predetermined bias voltage VBcalc. The value of the measured bias voltage VBIAS is used to determine the nature of the short circuit fault. There are three main types of short circuit fault: 1) A measured bias voltage VBIAS that is more than the predetermined bias voltage VBcalc indicates a fully charged fuel injector 12a, 12b which has a short circuit from its low side to the ground potential VGND. 2) A measured bias voltage VBIAS that is between the voltage of the second voltage rail V1 and the predetermined bias voltage VBcalc indicates a short circuit between the terminals of the actuator 11 of one of the fuel injectors 12a, 12b. However, a short circuit fault is considered not to be present if the measured bias voltage VBIAS is within a tolerance voltage of the predetermined voltage VBcalc. Note that the measured bias voltage VBIAS increases with an increase in the resistance of the short circuit. 3) A measured bias voltage VBIAS that is between the voltage of the second voltage rail V1 and the ground potential VGND indicates a high side to ground potential VGND short circuit fault. The measured bias voltage VBIAS for this type of short circuit is detected irrespective of the residual voltage across the fuel injectors 12a, 12b, and the measured bias voltage VBIAS increases with an increase in the effective resistance of the short circuit. Note that where the measured bias voltage VBIAS is around the voltage of the second voltage rail V1, it is sometimes not possible accurately to determine whether the short circuit fault is a short circuit between the terminals of the actuator 11 of one of the fuel injectors 12a, 12b, or a short circuit from the high side of an actuator 11 to the ground potential VGND. As mentioned previously, the range of measured bias voltages VBIAS which are within a tolerance voltage VBtol, either side of the predetermined bias voltage VBcalc, is not considered to indicate a short circuit fault because, at each of these measured bias voltage VBIAS, the piezoelectric actuator 11 is sufficiently charged to operate its associated fuel injector 12a, 12b. Typically, the tolerance voltage VBtol is within 10 Volts of the predetermined bias voltage VBcalc. When one of the fuel injectors 12a, 12b, for example the first fuel injector 12a, is selected by closing its associated selector switch SQ1, the measured bias voltage VBIAS increases to a predicted selected injector voltage VPinjN, that is substantially equal to the sum of the voltage of the second voltage rail V1 and the voltage across the selected injector VPinjN. When the fuel injector 12a is deselected, the associated selector switch SQ1 is opened and the measured bias voltage VBIAS exponentially decays to a voltage level set by the resistive bias network (i.e. the first and second resistors RH, RL). Where the measured bias voltage VBIAS decay is achieved rapidly, the circuit is arranged to have a time constant that minimises the exponential decay. When the reading of the measured bias voltage VBIAS is taken shortly after the deselection of the first fuel injector 12a, the measured bias voltage VBIAS should account for this exponential decay. Thus, for a time period after the deselection of the first fuel injector 12a, the measured bias voltage VBIAS will be greater than would normally be expected. Also, if the measurement is taken shortly after opening the selector switch SQ1 associated with the selected fuel injector 12a, the measured bias voltage VBIAS decreases. If a short circuit is not present in the drive circuit 20a, the measured bias voltage VBIAS decreases towards the predetermined bias voltage VBcalc. To avoid a varying measured bias voltage VBIAS, the measurement is taken after a predetermined time period. Alternatively, if the time constant of the exponential decay of the measured bias voltage VBIAS is known, this is accounted for by having a predetermined bias voltage VBcalc that is time dependent, decreasing from the predicted selected injector voltage VPinjN. If a short circuit fault is not detected, and the measured bias voltage VBIAS is within the accepted tolerance voltage VBtol of the predetermined bias voltage VBcalc, it is possible to use the resistive bias network to test for a fuel injector 12a, 12b with an open circuit fault. FIG. 4 shows an arrangement of the drive circuit 20a when testing for an open circuit fault having selected the second fuel injector 12b. The measured bias voltage VBIAS is again determined with all the switches (Q1, Q2, SQ1, SQ2, and RSQ) in the drive circuit 20a are open, with the exception of the second selector switch SQ2 that is associated with the selected, second fuel injector 12b. For a fault free fuel injector the measured bias voltage VBIAS is substantially equal to the predicted selected injector voltage VPinjN. If the selected fuel injector 12b has an open circuit fault, the measured bias voltage VBIAS is the voltage of the first voltage rail V0 as apportioned across the second resistor RL, when the voltage of the first voltage rail V0 is applied across the first and second resistors RH, RL in series. The measured bias voltage VBIAS is accepted when it is within the tolerance voltage VBtol of the predicted selected injector voltage VPinjN. Referring to FIG. 5, the diagnostic tests, or methods, for short and open circuit faults using the resistive bias network are carried out during normal running conditions at discrete points during the injection cycle. At completion of an injection, the drive pulse (the voltage across the fuel injector) is increased to the charge voltage level, VCHARGE, as shown in a first period 70. The bank then undergoes the regeneration phase in a second period 72. To perform the diagnostic method of testing for short and open circuit faults using the resistive bias network, all other activity on the bank 10, including the regeneration phase, is stopped at a point A at the beginning of a third period 74. All the switches associated with the bank 10, namely the charge and the discharge switches Q1, Q2, the first and second selector switches SQ1, SQ2 and the regeneration switch RSQ, are opened. The diagnostic methods of testing are then carried out. If a short circuit fault is not detected, the appropriate switches are closed and the regeneration phase is recommenced at a point B, at the beginning of a fourth period 76. Subsequently, the discharge phase occurs, where the drive pulse is reduced to the discharge voltage level, VDISCHARGE, in a fifth period 78, and an injection event occurs. Referring to FIG. 6, the preferred diagnostic method of testing using the resistive bias network whilst the bank 10 is in operation has a number of steps which are carried out during the third period 74 of the injection cycle. The diagnostic method of operating the resistive bias network will now be described in more detail. In a first step 80, all activity on the bank 10 is ceased, and all the switches (Q1, Q2, SQ1, SQ2 and RSQ) are open. In a second step 82, the voltage at the bias point PB is measured, without having closed one of the selector switches SQ1, SQ2. Thus, none of the fuel injectors 12a, 12b are selected. In a third step 84, the measured bias voltage VBIAS is assessed to determine if it is within the tolerance voltage VBtol of the predetermined bias voltage VBcalc. In a fourth step 86, if the measured bias voltage VBIAS is outside the tolerance voltage VBtol of the predetermined bias voltage VBcalc, a short circuit is present in the bank 10, and a short circuit fault response is initiated. Alternatively, if the measured bias voltage VBIAS is within the tolerance voltage VBtol of the predetermined bias voltage VBcalc, the fuel injector that is next to inject in the bank 10 in the injection cycle is tested for an open circuit fault. The fuel injector that is next to inject is selected by closing the selector switch SQ1, SQ2 associated with the fuel injector, as described previously. The measured bias voltage VBIAS is assessed in a fifth step 88 to determine if it is within the tolerance voltage VBtol of the predicted selected injector voltage VPinjN. In a sixth step 90, if the difference between the measured bias voltage VBIAS and the predicted selected injector voltage VPinjN is more than the voltage tolerance VBtol, an open circuit fault in the bank is detected, and an open circuit fault response is initiated. In a seventh step 92, if a fault is not detected on the bank 10, injection is enabled. The microprocessor 16 is configured to implement the method described above with reference to FIG. 6 whilst the drive circuit 20a and the bank 10 are in operation. Typically the method is embodied in a computer program, or a series of computer programs, stored in the memory 24 of the microprocessor 16 and executed by the microprocessor 16 to implement the method. Referring to FIG. 7, the diagnostic method of testing using the resistive bias network whilst the bank is in operation is adapted for use at start-up. In a first step 100, the charge switch Q1 is closed for a predetermined time. In a second step 102, all the switches (Q1, Q2, SQ1, SQ2 and RSQ) are opened and the voltage at the bias point PB is measured in order to detect short circuit faults in the drive circuit 20a. In a third step 104, the measured bias voltage VBIAS is assessed to determine if it is within the tolerance voltage VBtol of the predetermined bias voltage VBcalc. In a fourth step 106, if the measured bias voltage VBIAS is outside the tolerance voltage VBtol of the predetermined bias voltage VBcalc, a short circuit fault is detected in the drive circuit 20a, and a short circuit fault response is initiated. Alternatively, if the measured bias voltage VBIAS is within the tolerance voltage VBtol of the predetermined bias voltage VBcalc, no short circuit is detected. In a fifth step 108, the charge switch Q1 is re-closed for a calibrated time period in order to detect an open circuit fault in the drive circuit 20a. In a sixth step 110, the voltage at the bias point PB is measured, with one of the selector switches closed, for example the first selector switch SQ1 in order to select the first fuel injector 12a. In a seventh step 112, the measured bias voltage VBIAS is assessed to determine if it is within the tolerance voltage VBtol of the predicted selected injector voltage VPinjN. In an eighth step 114, if the measured bias voltage VBIAS at the bias point PB is not within the tolerance voltage VBtol of the predicted selected injector voltage VPinjN, an open circuit fault is detected that is associated with the selected fuel injector 12a, 12b, and an open circuit fault response is initiated; otherwise an open circuit fault has not been detected. After the eighth step 114, the method proceeds to the ninth step 116 in which the method returns to the sixth step 110 to test another of the fuel injectors 12a, 12b on the bank 10, for example the second fuel injector 12b. The sixth to the ninth steps 110, 112, 114, 116 are repeated until all the fuel injectors 12a, 12b on the bank 10 have been tested for an open circuit fault. Once all the fuel injectors 12a, 12b of a bank 10 have been individually tested, the method proceeds to a tenth step 118 in which other activity is enabled on the bank 10. The microprocessor 16 is configured to implement the method at start-up of the drive circuit 20a, using the resistive bias network as described above with reference to FIG. 7. Typically the method is embodied in a computer program, or a series of computer programs, stored in the memory 24 of the microprocessor 16 and executed by the microprocessor 16 to implement the method. In the fault trip circuit, the current through the fault trip resistor RF is monitored by the current sensor 27 that is operable by the microprocessor 16. In use, if a detected current Idect exceeds a predetermined threshold current Itrip, the circuit is arranged to trip, and the microprocessor 16 is arranged to initiate a signal. The drive circuit 20a is arranged to trip if one of the fuel injectors 12a, 12b has a low side, or a high side, short circuit fault to the ground potential VGND at any time when any of the switches (Q1, Q2, SQ1, SQ2 and RSQ) are closed. A number of arrangements of the switches (Q1, Q2, SQ1, SQ2 and RSQ) in the drive circuit 20a will now be described in detail with reference to FIGS. 8 to 11. In all these arrangements all of the switches (Q1, Q2, SQ1, SQ2 and RSQ) are open, unless specifically mentioned. Also, note that each of these figures has a bold line that represents the path in the drive circuit 20a taken by the short circuit current. In all these arrangements, the corresponding figures show the short circuit affecting the second fuel injector 12b. The short circuit might equally be located in the first fuel injector 12a, or any other fuel injector present in the bank 10. By operating the fault trip circuit, it is not possible to determine with which fuel injector of the bank 10 the fault is associated, because only one fault trip resistor RF is present in the drive circuit 20a. In another injector arrangement that comprises more than one bank 10 the fault trip circuit can detect the presence of a short circuit fault in the injector arrangement but cannot be used to identify the fuel injector 12a, 12b, or even the specific bank, with which the fault is associated. Referring to FIG. 8, when the discharge switch Q2 is closed and all the other switches (Q1, RSQ, SQ1 and SQ2) of the drive circuit 20a are open, a low side to ground potential VGND short circuit fault associated with the selected, second fuel injector 12b is detectable. Note that the short circuit shown in FIG. 8 is only detectable if there is residual charge on the second fuel injector 12b. Referring to FIG. 9, when the second selector switch SQ2 is closed and all the other switches (Q1, Q2, SQ1 and RSQ) of the drive circuit 20a are open it is possible to detect a high side to ground potential VGND short circuit fault associated with the second fuel injector 12b. Referring to FIGS. 10 and 11, on closing the charge switch Q1, when all the other switches (RSQ, Q2, SQ1 and SQ2) of the drive circuit 20a are open, two possible short circuit faults are detectable. In the drive circuit 20a shown in FIG. 10, there is a high side short circuit fault to the ground potential VGND that is associated with the second fuel injector 12b. In the drive circuit 20a in FIG. 11, there is a low side short circuit fault to the ground potential VGND, associated with the second fuel injector 12b. Note that the short circuit shown in FIG. 11 is only detectable if there is little, if any, residual charge on the second fuel injector 12b. In each of FIGS. 12 and 13, the regeneration switch RSQ is closed, and all the other switches (Q1, Q2, SQ1 and SQ2) of the drive circuit 20a are open. In the drive circuit 20a shown in FIG. 12 a high side to ground potential VGND short circuit fault that is associated with the second fuel injector 12b is detectable. In the drive circuit 20a shown in FIG. 13 a low side to ground potential VGND short circuit fault that is associated with the second fuel injector 12b is detectable. However, the short circuit fault shown in FIG. 13 is only detectable if there is no, or negligible, charge on the selected, second fuel injector 12b. During one injection cycle of the given fuel injector 12a, 12b whilst the drive circuit 20a is operating under normal running conditions, the drive circuit 20a is operated through the operating states shown in FIGS. 9 to 13. Thus, all of the different types of short circuit fault that are described above in reference to FIGS. 9 to 13 are detectable. It will be appreciated that the arrangement shown in FIG. 8 does not occur in the injection cycle. As mentioned previously, in an injector arrangement comprising more than one bank, it is not possible to determine with which bank a short circuit fault is associated during normal running conditions when using the fault trip circuit. In addition, where one of the banks comprises more than one fuel injector 12a, 12b, it is also not possible to identify, by using this fault trip circuit during normal running conditions, with which fuel injector 12a, 12b on the bank that the fault is associated. In order to determine with which bank the fault is associated, the fault trip circuit may be tripped deliberately at start-up. The circuitry of the fault trip circuit is tripped deliberately at start-up by operating the regeneration switch RSQ of a bank 10, or the discharge switch Q2 of the associated drive circuit 20a, as shown in FIGS. 8, 12 and 13. The fault trip circuit is used in preference to the resistive bias network at start-up because the resistive bias network is less reliable at start-up than the fault trip circuit due to the possibility of unknown voltages being present across the fuel injectors 12a, 12b. FIG. 14 shows, in the form of a flow diagram, the steps of the method used to trip the fault trip circuit deliberately when applied to an injector arrangement comprising at least two banks: the first bank 10, and a second bank 10b. If the injector arrangement comprises more than two banks, the same steps that are applied to each of the first two banks 10, 10b are then applied to the third and further banks, 10c to 10N, in turn. Starting with a first step 120, the regeneration switch RSQ is closed on the first bank 10 of the injector arrangement for a predetermined period of time. In a second step 122 the current flowing through the fault trip resistor RF is monitored in order to measure the detected current Idect. If the detected current Idect exceeds the threshold current Itrip, in a third step 124, a short circuit fault response is initiated. The testing of the first bank 10 is now complete, and the method proceeds directly to a sixth step 130. Alternatively, if the measured current does not equal or exceed the threshold current Itrip, the discharge switch Q2 of the first bank 10 is closed for a predetermined amount of time. In a fourth step 126, the current passing through the fault trip resistor RF is monitored in order to measure the detected current Idect. In a fifth step 128, if the detected current Idect exceeds the threshold current Itrip, a short circuit fault response is initiated. The testing of the first bank 10 is now complete. The method continues by testing the second bank 10b. In the sixth step 130, the regeneration switch RSQ of the second bank 10b is closed for a predetermined amount of time. In a seventh step 132, the current passing through the fault trip resistor RF is monitored to measure the detected current Idect. In an eighth step 134, if the detected current Idect is in excess of the threshold current Itrip, a short circuit fault response is initiated and the testing of the second bank 10b is complete. The injector arrangement is now ready for start-up. Alternatively, if the measured current does not equal or exceed the threshold current Itrip, the discharge switch Q2 of the second bank 10b is closed for a predetermined amount of time. In a ninth step 136, the current passing through the fault trip resistor RF is monitored to measure the detected current Idect. In a tenth step 138, if the measured current is in excess of the threshold current Itrip, a short circuit fault response is initiated. In using this diagnostic method at start up, only one bank is active at a time. All other activities on the injector arrangement are disabled whilst this diagnostic method of testing is in progress. Thus, the bank 10, 10b in which the short circuit fault is present is identifiable. The microprocessor 16 is configured to implement the diagnostic methods of testing the drive circuit 20a using the fault trip circuit at start-up, and during normal running conditions of the drive circuit 20a. Typically the method is embodied in a computer program, or a series of computer programs, stored in the memory 24 of the microprocessor 16 and executed by the microprocessor 16 to implement these methods. In the preferred embodiment, both the fault trip circuit and the bias network are present in the drive circuit 20a. They are used independently to detect short circuits, but only the bias network is capable of being used to detect open circuit faults. These two diagnostic tools are, thus, complementary. As mentioned previously, where the fault trip circuit is used during normal running conditions of an injector arrangement that has at least two banks 10, 10b, it is not possible to determine with which the bank the short circuit fault is associated. At start-up, as an alternative to tripping the fault trip circuit deliberately, the resistive bias network can be used to identify with which bank 10, 10b the short circuit is associated, because there is a bias network integrated into each drive circuit 20a, 20b. The bank 10, 10b is identified by applying to each of the drive circuits 20a, 20b the diagnostic method in which the bias network is used. The steps of the diagnostic method in which the resistive bias network is used to detect open circuit faults may be combined with the diagnostic method in which the fault trip circuit is used. The combined diagnostic method can therefore detect reliably both short and open circuit faults at start-up. At start-up of an injector arrangement that has at least two banks 10, 10b (each having an associated drive circuit 20a, 20b) it is preferable to apply the diagnostic method in which the fault trip circuit is used, instead of the bias network. This is because the diagnostic method in which the bias network is used is limited in its performance by the presence of an unknown voltage across each of the fuel injectors 12a, 12b. However, because it is not possible to detect open circuit faults using the fault trip circuit, the diagnostic method in which the resistive bias network is used is applied to each of the drive circuits 20a, 20b of the injector arrangement after the diagnostic method using the fault trip circuit has been applied. Having described preferred embodiments of the present invention, it is to be appreciated that the embodiments in question are exemplary only and that variations and modifications, such as will occur to those possessed of the appropriate knowledge and skills, may be made without departure from the scope of the invention as set forth in the appended claims. The diagnostic methods in which the resistive bias network is used are capable of detecting both short and open circuit faults. These methods may be used to detect these two types of fault separately, instead of together as described for the preferred embodiment. Thus the resistive biasing network may be adapted to test only for short circuit faults or only for open circuit faults. Only one of the two aforementioned diagnostic tools, the resistive bias network and the fault trip circuit, may be included in the drive circuit 20a. The drive circuit 20a herein described is a generic drive circuit. The resistive bias network and fault trip circuit may be adapted for use with similar drive circuits which obviate the need for a dedicated power supply, for example, the drive circuits described in WO 2005/028836. Other types of drive circuit may be used with each of the diagnostic tools. For example, the drive circuit may only have one voltage rail, or it may not have the circuitry that is used in the regeneration phase. In the aforementioned description the drive circuit 20a is integrated within the ECM 14. In another embodiment, however, the drive circuit 20a is separate from, but connected to, the rest of the ECM 14. In the aforementioned description, the fuel injectors 12a, 12b are of a negative-charge displacement type. However, in another embodiment the fuel injectors 12a, 12b are of a positive-charge displacement type, in which case the drive circuits 20a are configured with the fuel injectors 12a, 12b so that the fuel injectors 12a, 12b are open to inject fuel during a charging phase and are closed to terminate fuel injection during a discharge phase. In an injector arrangement that has more than two banks, the method of operating the fault trip circuit at start up is applied to each of the banks of the injector arrangement. After the first two banks 10, 10b have been tested, the method is repeated from the sixth step 130 to the tenth step 138, inclusive, on each of the third and further banks 10c to 10N. In a further variation of the preferred embodiment, the fault trip resistor RF operates as the current sensor 27. The diagnostic methods that test the drive circuit 20a for short circuit faults to the ground potential VGND are also capable of detecting equivalent short circuits to the voltage VBAT of the engine battery. In modifications of the preferred embodiment, the tolerance voltage may be any value so that the measured bias voltage is sufficient to operate the fuel injector 12a, 12b concerned. For example, the tolerance voltage may be between 5 and 20 Volts. Note that it is not necessary to shut down a bank in the case of a single open circuit fuel injector because the other fuel injectors in the bank are able to function normally. In such a bank, it is still possible to inject on any other of the fuel injectors in the bank and it is still possible to perform regeneration. In a variation of the preferred embodiment, each bank has a current sensor 27. In such a drive circuit it would be possible using the plurality of current sensors 27 to determine with which bank a detected short circuit fault is associated, because the fault is only detectable by the current sensor 27 of the bank associated with the fault. Although the preferred embodiment refers to only two injectors 12a, 12b on a bank 10, in variations a bank may have a plurality of injectors 12a to 12N, with a corresponding number of selector switches SQ1 to SQN.
|
F
|
F02
|
F02M
|
51
|
00
|
||||
11810788
|
US20070280392A1-20071206
|
Clock and data recovery method and corresponding device
|
ACCEPTED
|
20071122
|
20071206
|
[]
|
H04L700
|
["H04L700"]
|
7978801
|
20070606
|
20110712
|
375
|
355000
|
96284.0
|
FOTAKIS
|
ARISTOCRATIS
|
[{"inventor_name_last": "De Laurentiis", "inventor_name_first": "Pierpaolo", "inventor_city": "Milano", "inventor_state": "", "inventor_country": "IT"}, {"inventor_name_last": "Ferrari", "inventor_name_first": "Lina", "inventor_city": "Milano", "inventor_state": "", "inventor_country": "IT"}, {"inventor_name_last": "Manzoni", "inventor_name_first": "Stefano", "inventor_city": "Cernusco S/N", "inventor_state": "", "inventor_country": "IT"}]
|
A clock and data recovery method comprising the following steps: an oversampling step wherein an oversampled stream of samples is generated from an input data stream at a data rate by using reference clock signal at a clock rate, the clock rate being higher than the data rate, and a tracking step of the input data stream realised by locating transitions between adjacent samples of the oversampled stream and by moving a no transition area within the oversampled stream wherein no transitions between adjacent samples are found a recovered data signal being obtained as a central portion of the no transition area and a recovered clock signal being obtained by dividing the reference clock signal. A clock and data recovery device is also described.
|
1. A clock and data recovery method, comprising the following steps: oversampling an input data stream at a data rate by using reference clock signal at a clock ratehigher than the data rate, producing an oversampled stream; tracking the input data stream by locating transitions between adjacent samples of the oversampled stream and moving a no-transition area within the oversampled stream wherein no transitions between adjacent samples are found; and recovering a data signal as a central portion of the no-transition area and recovery a clock signal by dividing the reference clock signal. 2. The clock and data recovery method of claim 1 wherein the tracking step uses a search window of a subset of the oversampled stream samples, centered with respect to said input data stream. 3. The clock and data recovery method of claim 2, further comprising: a first search state, wherein said subset of oversampled stream samples corresponding to said search window are checked in order to find said no-transition area; when said no-transition area is found, the method switching into, a second track state, wherein said subset of oversampled stream samples corresponding to said search window are checked to verify that no transition occurs between adjacent samples, and analyzed to track the input data stream aligning accordingly to said reference clock signal, the method coming back to said first search state when a transition occurs. 4. The clock and data recovery method of claim 3 wherein said first search state comprises: an initialising sequence; a main loop to count a number of times without any transition in said input data stream; a first auxiliary loop to count a number of a first driving command (SLIP) with respect to a number of said oversampled stream samples; a second auxiliary loop to verify whether a minimum eye aperture condition is verified; and the method providing a first and second output conditions from said first search state corresponding to a change of state and to an alarm for no eye aperture found. 5. The clock and data recovery method of claim 4 wherein said main loop comprises: a first verify step wherein a first condition is checked; a first counting step wherein a first counter is incremented; and a second verify step wherein it is located when said first counter is equal to a first value; the method changes from said main loop to said first auxiliary loop when said first condition is not verified and a transition occurs before said first value is reached. 6. The clock and data recovery method according to claim 5 wherein, in case said first counter is equal to said first value, the method further comprises a first assertion step wherein a first state parameter is asserted, said first counter keeping count of how many times no transitions are found in said search window. 7. The clock and data recovery method of claim 6 wherein said first counter it is set equal to 0 and reset when it reaches said first value, such value being equal to the number of times without transitions in order to assert said first state parameter and provide said first output condition corresponding to a first change of state to move the method from said first search state to said second track state. 8. The clock and data recovery method of claim 6 wherein said first auxiliary loop comprises: a first searching step wherein said subset of oversampled stream samples is scrolled up starting from a central position of said search window; a third verify step wherein it is verified when a second counter is equal to a count value; and a second counting step wherein said second counter is incremented, said second counter keeps count of how many scroll of said subset of oversampled stream samples have been taken; the method changes from said first auxiliary loop to said second auxiliary loop when said second counter is equal to said count value; otherwise the method returns to said first verify step. 9. The clock and data recovery method of claim 8 wherein said second counter is set equal to 0, and reset at said count value after said oversampled stream has been all scanned, N being the number of said samples. 10. The clock and data recovery method of claim 9 wherein said second auxiliary loop comprises: a third counting step wherein a current width of said search window is narrowed; and a fourth verify step wherein it is verified when said current width is narrower than a boundary condition parameter. 11. The clock and data recovery method of claim 10 wherein, if said current width of said search window is not narrower than said boundary condition parameter, the method further comprises a first reset step, wherein said second counter is set equal to 0 and the method goes back to said first verify step and otherwise, the method comprises a final assertion step wherein said driving parameter is asserted and said second output condition corresponding to an alarm for no eye aperture found is provided. 12. The clock and data recovery method of claim 11 wherein said current width of said search window is set at an initial value, and reset when said first or said second output condition is provided, while said boundary condition parameter defines a minimum eye aperture that can be detected in said input data stream corresponding to said second output condition. 13. The clock and data recovery method of claim 3 wherein, in said second track state, the method comprises a checking phase of transitions in a first and a second subset of oversampled stream samples by means of respective track vectors in order to decide whether said oversampled stream is to be not scrolled, scrolled up or scrolled down, a length of said track vectors being programmable, said track vectors (VU, VD) latching the transitions within said first and second subset of oversampled stream samples, said checking phase being recursive. 14. The clock and data recovery method of claim 13 wherein said second track state comprises: an initialising sequence; a first waiting loop for a threshold number of cycles of the reference clock; a check and assertion sequence wherein a third output condition corresponding to a second change of state from the said track state to said search state is provided; and a second tracking loop where said track vectors are analyzed in order to take a proper decision to track said input data stream. 15. The clock and data recovery method of claim 14 wherein said first waiting loop of said second track state comprises: a fifth verify step wherein a fourth counter of cycles of said oversampling clock is compared with a parameter that defines a waiting time and that is programmable; and a fourth counting step wherein said fourth counter is incremented. 16. The clock and data recovery method of claim 15 wherein said fifth verify step is substituted by a counting step wherein said transitions are separately counted for each samples of said oversampled stream. 17. The clock and data recovery method of claim 15 wherein it further comprises: a second reset step wherein said counter is set equal to 0 once it has reached a value equal to said parameter that defines a waiting time; a sixth verify step wherein said subset of oversampled stream samples corresponding to said search window are checked in order to find out if a transition has occurred; and in case a transition has occurred in said search window, the method further comprises a third assertion step wherein a second state parameter is asserted and said third output condition corresponding to a second change of state to move the method from said second track state to said first search state is provided, otherwise, the method changes from said first waiting loop to said second tracking loop. 18. The clock and data recovery method of claim 17 wherein said second tracking loop comprises: a seventh verify step wherein a fifth counter is compared with said length of said track vectors; and if the value of said fifth counter is equal to said length, then said fifth counter is set to 1 and the method further comprises: a fourth assertion step, wherein a third state parameter is asserted; and a first decision step, wherein first and second driving commands are kept on hold. 19. The clock and data recovery method of claim 18 wherein, if the value of said fifth counter is not equal to said length, the method further comprises: a fifth assertion step, wherein a fourth state parameter is asserted; and an eighth verify step, wherein it is checked a first condition corresponding to whether the j-th bits of said track vectors are both equal to 1. 20. The clock and data recovery method of claim 19 wherein, if said first condition is verified, then the method further comprises: a second decision step, wherein said first and second driving commands are kept on hold; otherwise, the method comprises: a ninth verify step, wherein it is checked a second condition corresponding to whether or not the j-th bit of said first track vector is equal to 1 and the j-th bit of said second track vector is equal to 0 and, is said second condition is verified, a third decision step, wherein a first decision corresponding to said first driving command is taken corresponding to said oversampled stream being scrolled up. 21. The clock and data recovery method of claim 20 wherein, if said second condition is not verified, the method further comprises: a tenth verify step, wherein it is checked a third condition corresponding to whether or not the j-th bit of said first track vector is equal to 0 and the j-th bit of said second track vector is equal to 1; and, if said third condition is verified a fourth decision step, wherein a second decision corresponding to said second driving command is taken corresponding to said oversampled stream being scrolled down. 22. The clock and data recovery method of claim 21 wherein, if said third condition is not verified, the method further comprises: a fifth counting step, wherein said fifth counter is incremented and after which the method returns to said seventh verify step. 23. The clock and data recovery method of claim 18 wherein, each time a decision step is executed, the method returns to said fifth verify step and said fifth counter is set to 1. 24. A clock and data recovery device comprising: a first input terminal configured to receive an input data stream at a data rate; a second input terminal configured to receive a reference clock signal at a clock rate higher than the data rate; a first output terminal providing a recovered data signal; a second output terminal providing a recovered clock signal; a serial-to-parallel converter coupled to said first input terminal and to said second input terminal and having a parallel output, the first input bit of a current word of said input data stream being at the N-th output terminal and the N-th input bit of a current word of said input data stream being at the first output terminal, a central output terminal being coupled to said first output terminal of said clock and data recovery device and providing said recovered data signal (RDATA) at said data rate; and a divider coupled to a detection and decision block, said second input terminal of said clock and data recovery device and said second output terminal of said clock and data recovery device and providing said recovered clock signal, said detection and decision block having a parallel input connected to the parallel output terminals of said serial-to-parallel converter of said oversampling portion. 25. The clock and data recovery device of claim 24 wherein said second output terminal is coupled to said serial-to-parallel converter. 26. The clock and data recovery device of claim 24 wherein said detection and decision block comprises a detection block and a decision block coupled to each other, said detection block having said parallel input coupled to said parallel output of said serial-to-parallel converter and said decision block has a first and second output terminals coupled to respective first and second input terminals (IN5, IN5*) of said divider and providing thereto respective first and second driving signals, which change a dividing ratio of said divider of +1 and −1, respectively. 27. The clock and data recovery device of claim 26 wherein said first and second driving signals drive said serial-to-parallel converter in order to move and keep a no-transition area wherein no transitions between adjacent samples are found in a middle of said parallel output. 28. The clock and data recovery device of claim 24 wherein said serial-to-parallel converter of said oversampling portion comprises a hold portion to store a last input bit of a previous input data stream, said hold portion having a further output terminal wherein a last input bit of a previous word of said input data stream is provided at the same time of the N input bits of a current input data stream and which is connected to a further input terminal of said detection and decision block. 29. A clock and data recovery device, comprising: a serial-to-parallel converter configured to oversample an input data stream at a reference clock rate higher than a data rate of the input data stream and having a number of parallel outputs for a current data word; and a tracking module coupled to the number of parallel outputs of the serial-to-parallel converter and configured to produce a recovered clock signal for the input data stream and to generate a control signal to cause the serial-to-parallel converter to provide a recovered data signal on an output of the number of parallel outputs. 30. The clock and data recovery device of claim 29, further comprising: an input to receive a reference clock signal coupled to the serial-to-parallel converter and the tracking circuit. 31. The clock and data recovery device of claim 30 wherein the tracking module comprises a divider configured to receive the reference clock signal and to provide the control signal to the serial-to-parallel converter. 32. The clock and data recovery device of claim 31 wherein, the serial-to-parallel converter has an output for a last input bit of a previous word coupled to the tracking module; and the output providing the recovered data signal is a middle output in the number of parallel outputs. 33. The clock and data recovery device of claim 32 wherein the tracking module is configured to: detect transitions between adjacent samples provided by the serial-to-parallel converter; and selectively change a dividing ratio of the divider based on the detection of a transition. 34. The clock and data recovery device of claim 32 wherein the control signal causes the serial-to-parallel converter to maintain a no-transition window on outputs in the number of parallel outputs adjacent to the output providing the recovered data signal. 35. A system, comprising: a reference clock configured to generate a reference clock signal; a serial-to-parallel converter configured to oversample an input data stream using the reference clock signal and having a number of parallel outputs for a current data word; and a tracking module coupled to the number of parallel outputs of the serial-to-parallel converter and configured to produce a recovered clock signal for the input data stream and to generate a control signal to cause the serial-to-parallel converter to provide a recovered data signal on a middle output of the number of parallel outputs, the reference clock signal having a frequency higher than a data rate of the input data stream. 36. The system of claim 35 wherein the tracking module comprises a divider configured to receive the reference clock signal and to provide the control signal to the serial-to-parallel converter. 37. The system of claim 35 wherein the serial-to-parallel converter has an output for a last input bit of a previous word coupled to the tracking module. 38. The system of claim 37 wherein the tracking module is configured to: detect transitions between adjacent samples provided by the serial-to-parallel converter; and selectively change a dividing ratio of the divider based on the detection of a transition. 39. The system of claim 38 wherein the control signal causes the serial-to-parallel converter to maintain a no-transition window on outputs in the number of parallel outputs adjacent to the middle output. 40. The system of claim 35 wherein the reference clock signal frequency is equal to the number of parallel outputs multiplied by the data rate of the input data stream.
|
<SOH> BACKGROUND <EOH>1. Technical Field The present disclosure relates to a clock and data recovery method and corresponding device. The description particularly, but not exclusively, relates to a clock and data recovery method for an ASIC chip designed for telecom/datacom applications and the following description is made with reference to this field of application for convenience of explanation only. 2. Description of the Related Art An ASIC (acronym from Application-Specific Integrated Circuit) is a chip designed for a particular application. It typically consists of a core logic, where the specific application is implemented, and an in/out interface, that connects the specific application to the overall system. An ASIC for telecom/datacom applications generally includes, as an input/output interface, a SERDES interface (serial-to-parallel/parallel-to-serial interface). Its goal is to adapt high speed serial data rate of a data line to a low speed parallel data rate of the chip core. Line data rate is linked to bandwidth requirements of communication systems and limited by technology. Core data rate is linked to the available technology (for instance, the CMOS technology presently used) in terms of both maximum operating frequencies and digital design tools. Apart from the individual trends of line and core data rates (the former growing up faster than the latter), new applications typically require a certain degree of back-compatibility with respect to old applications. Hence, an ASIC is generally able to treat a high data rate as well as a low data rate through the very same SERDES interface. It should be noted that the low data rate is usually an integer sub-rate of the high data rate. More particularly, for telecom/datacom applications in data transmission through ASICs, the reliability and the quality of a data link or generally of a communication line depends on the timing control. In addition, the transmission of a clock signal from one end to the other of a communication line in a telecom/datacom system is expensive, both because the clock signal is not a payload and because of technology limitations due to its bandwidth. Nowadays, the latter issue is usually solved in the field by double data rate interfaces. According to this solution, both the rising and the falling edges of the clock signal are used as reference events (in contrast with normal data rate interfaces where only one type of edge, the rising or falling one, of the clock signal is used as a reference event). In this way data and clock signals have the very same physical bandwidth. However, the known solutions are still affected by the former problem. Moreover, communication lines with a clock signal transmitted therethrough have strong timing budget requirements, which become harder and harder to meet when the data rate increases, since the bit period becomes smaller and smaller. The most popular way to control timing is by embedding a clock signal into the transmitted data and recovering the timing information at the receiver side of the communication line by means of a clock and data recovery device (CDR in the following). In particular, the CDR recovers the timing information based on the transitions of input data, under the assumption that the nominal bit period is constant, thus producing a recovered data signal as well as a recovered clock signal. Then, taking recovered data and clock signals from the CDR, a serial to parallel converter matches the line data rate and the core data rate. Traditionally, analog phase-locked loops (PLL) have been used to implement CDR devices. Although, in general, an analog PLL can operate at high frequencies, it suffers from problems such as, for instance, the frequency drift during long sequences of identical bits (also indicated as CID, Consecutive Identical Digits) and the difficult lock acquisition process (at the power on or after a loss of synchronization). Being a CDR using analog PLL a fully analog solution, high performances are expected, but they are paid in terms area and power consumption. Another drawback is a hardly portable design through technologies. CDRs of this kind are described in the following references: U.S. Pat. No. 4,949,051 issued on Aug. 14, 1990 to J. P. Viola and concerning a “Phase lock clock recovery with aided frequency acquisition”; “A monolithic 622 Mb/s clock extraction data retiming circuit”, Benny Lai, Richard C. Walker, ISSCC Dig. Tech. Papers, pp. 144-145, February 1991; and “An analog PLL-based clock and data recovery circuit with high input jitter tolerance” Sam Y. Sun, IEEE JSSC vol. SC-24, pp. 325-330, April 1989. Another approach to timing or clock recovery is the digital one. Here, the smallest possible analog front end is used to generate timing information that feeds a recovery algorithm. This algorithm is usually described and implemented using a high level language (VHDL). In this way, a certain degree of portability through technologies is possible as well as some area and power saving. On the other hand, it is difficult to obtain high performance devices. Digital timing recovery in a serial connection line is typically done by a CDR device in two ways that are by tracking and by oversampling. In a tracking CDR, an optimum sampling phase is chosen among a discrete set, by an appropriate algorithm, and the output data is the input data which is sampled by the selected sampling phase. CDRs of this kind are described in the following references: U.S. Pat. No. 5,812,619 issued on Sep. 22, 1998 to Runaldue and concerning a: “Digital phase lock loop and system for digital clock recovery”; “A tracking clock recovery receiver for 4-Gbps signaling”, J. Poulton, W. I. Dally, S. Tell, IEEE Micro Vol. 18 Issue 1, pp. 25-27, January/February 1998; and “A semi-digital delay-locked loop using an analog-based FSM”, W. Rhee, B. Parker, D. Friedman, IEEE Trans. on Cir. and Sys. II: E. B. Vol. 51 Issue: 11, pp. 635-639, November 2004. In an oversampling CDR, the input data are sampled by more than one phase at the same time and an algorithm takes the decision of which value has been sampled. CDRs of this kind are described in the following references: U.S. Pat. No. 6,611,219 issued on Aug. 26, 2003 to Lee et al. and concerning an: “Oversampling data recovery apparatus and method”; “A 1.0 Gbps CMOS oversampling data recovery circuit with fine delay generation method” J.-Y. Park, J. K. Kang, IEICE Trans. Fund. Vol. E83 No. 6, June 2000; and “A 0.5 um CMOS 4.0 Gb/s serial link transceiver with data recovery using oversampling”, C.-K. K. Yang, R. Farjad-Rad, M. A, Horowitz, IEEE JSSC Vol. 33 No. 5, May 1998. A strong difference between tracking and oversampling CDRs is that the former solution recovers the clock while the latter recovers the data. In other words, the output of a tracking CDR is a data-clock pair with a known phase relationship, while the output of an oversampling CDR is typically a data signal. The main drawbacks of the above described solutions are as follows: custom design is still rather dominant so technology portability is difficult; efforts and tradeoffs are required to cover wide data rate ranges; the scalability is more and more difficult with increasing data rate. The technical problem underlying the present description is that of providing a clock and data recovery method and corresponding device having structural and functional characteristics which allow to improve the scalability with different technologies and frequencies, in this way overcoming the limits which still affect the conventional methods and devices.
|
<SOH> BRIEF SUMMARY <EOH>An embodiment of the present invention provides a clock and data recovery method and corresponding device able to mix the tracking and oversampling features using a serial-to-parallel converter that oversamples the input data and a divider that can be controlled to track input data. In one aspect, a clock and data recovery method comprises the following steps: an oversampling step wherein an oversampled stream of samples is generated from an input data stream (IDS) at a data rate by using reference clock signal (CK) at a clock rate, said clock rate being higher than said data rate, and a tracking step of said input data stream (IDS) realised by locating transitions between adjacent samples of said oversampled stream and by moving a no transition area within said oversampled stream wherein no transitions between adjacent samples are found, a recovered data signal (RDATA) being obtained as a central portion of said no transition area and a recovered clock signal (RCK) being obtained by dividing said reference clock signal (CK). In one embodiment, said tracking step uses a search window (SW) of a subset of said oversampled stream samples, centred with respect to said input data stream (IDS). In one embodiment, the method further comprises: a first search state, wherein said subset of oversampled stream samples corresponding to said search window (SW) are checked in order to find said no transition area; when said no transition area is found, the method switching into, a second track state, wherein said subset of oversampled stream samples corresponding to said search window (SW) are checked in order to verify that no transition occurs between adjacent samples, and analyzed in order to track the input data stream aligning accordingly to said reference clock signal (CK), the method coming back to said first search state when a transition occurs. In one embodiment, said first search state comprises: an initialising sequence (S 1 , S 2 , S 3 ); a main loop (A), to count a number of times without any transition in said input data stream (IDS); a first auxiliary loop (B), to count a number of a first driving command (SLIP) with respect to a number of said oversampled stream samples; a second auxiliary loop (C), to verify whether a minimum eye aperture condition is verified or not; the method providing a first and second output conditions from said first search state corresponding to a change of state (TS, S 7 ) and to an alarm for no eye aperture found (S 14 ). In one embodiment, said main loop (A) comprises: a first verify step (S 4 ), wherein a first condition (PO[N−k]= . . . =PO[k−1]) is checked; a first counting step (S 5 ), wherein a first counter (SEARCH_CNT) is incremented; and a second verify step (S 6 ), wherein it is located when said first counter (SEARCH_CNT) is equal to a first value (N_LOCK), the method changes from said main loop (A) to said first auxiliary loop (B) when said first condition is not verified and a transition occurs before said first value (N_LOCK) is reached. In one embodiment, in case said first counter (SEARCH_CNT) is equal to said first value (N_LOCK), the method further comprises a first assertion step (S 7 ) wherein a first state parameter (LOCK) is asserted, said first counter (SEARCH_CNT) keeping count of how many times no transitions are found in said search window (SW). In one embodiment, said first counter (SEARCH_CNT) it is set equal to 0 and reset when it reaches said first value (N_LOCK), such value being equal to the number of times without transitions in order to assert said first state parameter (LOCK) and provide said first output condition corresponding to a first change of state (TS) to move the method from said first search state to said second track state. In one embodiment, said first auxiliary loop (B) comprises: a first searching step (S 8 ), wherein said subset of oversampled stream samples is scrolled up starting from a central position of said search window (SW); a third verify step (S 9 ), wherein it is verified when a second counter (SLIP_CNT) is equal to a count value (N−1); and a second counting step (S 10 ), wherein said second counter (SLIP_CNT) is incremented, said second counter (SLIP_CNT) keeps count of how many scroll of said subset of oversampled stream samples have been taken, the method changes from said first auxiliary loop (B) to said second auxiliary loop (C) when said second counter (SLIP_CNT) is equal to said count value (N−1); otherwise the method returns to said first verify step (S 4 ). In one embodiment, said second counter (SLIP_CNT) is set equal to 0, and reset at said count value (N−1) after said oversampled stream has been all scanned, N being the number of said samples. In one embodiment, said second auxiliary loop (C) comprises: a third counting step (S 11 ), wherein a current width (N−2*k) of said search window (SW) is narrowed; and a fourth verify step (S 12 ), wherein it is verified when said current width (N−2*k) is narrower than a boundary condition parameter (MIN_EYE_APE). In one embodiment, if said current width (N−2*k) of said search window (SW) is not narrower than said boundary condition parameter (MIN_EYE_APE), the method further comprises a first reset step (S 13 ), wherein said second counter (SLIP_CNT) is set equal to 0 and the method goes back to said first verify step (S 4 ) and otherwise, the method comprises a final assertion step (S 14 ) wherein said driving parameter (NO_EYE) is asserted and said second output condition corresponding to an alarm for no eye aperture found is provided. In one embodiment, said current with (N−2*k) of said search window (SW) is set at an initial value (N−2*k 0 ), and reset when said first or said second output condition is provided, while said boundary condition parameter (MIN_EYE_APE) defines a minimum eye aperture that can be detected in said input data stream (IDS) corresponding to said second output condition. In one embodiment, in said second track state, the method comprises a checking phase of transitions in a first and a second subset of oversampled stream samples by means of respective track vectors (VU, VD) in order to decide whether said oversampled stream is to be not scrolled, scrolled up or scrolled down, a length (TW) of said track vectors (VU, VD) being programmable, said track vectors (VU, VD) latching the transitions within said first and second subset of oversampled stream samples, said checking phase being recursive. In one embodiment, said second track state comprises: an initialising sequence; a first waiting loop (D), where nothing is done for N_WAIT cycles of an oversampling clock; a check and assertion sequence (S 18 , S 19 , SS) wherein a third output condition corresponding to a second change of state (SS) from the said track state to said search state is provided; a second tracking loop (E), where said track vectors are analyzed in order to take a proper decision to track said input data stream (IDS). In one embodiment, said first waiting loop (D) of said second track state comprises: a fifth verify step (S 15 ), wherein a fourth counter (W_CNT) of cycles of said oversampling clock is compared with a parameter (N_WAIT) that defines a waiting time and that is programmable; and a fourth counting step (S 16 ), wherein said fourth counter (W_CNT) is incremented. In one embodiment, said fifth verify step (S 15 ) is substituted by a counting step wherein said transitions are separately counted for each samples of said oversampled stream. In one embodiment, the clock and data recovery method further comprises: a second reset step (S 17 ), wherein said counter (W_CNT) is set equal to 0 once it has reached a value equal to said parameter (N_WAIT) that defines a waiting time; a sixth verify step (S 18 ), wherein said subset of oversampled stream samples corresponding to said search window (SW) are checked in order to find out if a transition has occurred; and in case a transition has occurred in said search window (SW), the method further comprises a third assertion step (S 19 ) wherein a second state parameter (UNLOCK) is asserted and said third output condition corresponding to a second change of state (SS) to move the method from said second track state to said first search state is provided, otherwise, the method changes from said first waiting loop (D) to said second tracking loop (E). In one embodiment, said second tracking loop (E) comprises: a seventh verify step (S 20 ), wherein a fifth counter (J) is compared with said length (TW) of said track vectors (VU, VD) and if the value of said fifth counter (J) is equal to said length (TW), then said fifth counter (J) is set to 1 and the method further comprises: a fourth assertion step (S 21 ), wherein a third state parameter (NO_TRAN) is asserted; and a first decision step (S 22 ), wherein first and second driving commands (SLIP/PILS) are kept on hold (DO_NOTHING). In one embodiment, if the value of said fifth counter (J) is not equal to said length (TW), the method further comprises: a fifth assertion step (S 23 ), wherein a fourth state parameter (TRAN) is asserted; and an eighth verify step (S 24 ), wherein it is checked a first condition corresponding to whether the j-th bits of said track vectors (VU, VD) are both equal to 1 (VU[j]=VD[j]=1) or not. In one embodiment, if said first condition is verified, then the method further comprises: a second decision step (S 25 ), wherein said first and second driving commands (SLIP/PILS) are kept on hold (DO_NOTHING); otherwise, the method comprises: a ninth verify step (S 26 ), wherein it is checked a second condition corresponding to whether or not the j-th bit of said first track vector (VU) is equal to 1 and the j-th bit of said second track vector (VD) is equal to 0 (VU[j]=1; VD[j]=0) and, is said second condition is verified, a third decision step (S 27 ), wherein a first decision corresponding to said first driving command (SLIP) is taken corresponding to said oversampled stream being scrolled up. In one embodiment, if said second condition is not verified, the method further comprises: a tenth verify step (S 28 ), wherein it is checked a third condition corresponding to whether or not the j-th bit of said first track vector (VU) is equal to 0 and the j-th bit of said second track vector (VD) is equal to 1; and, if said third condition is verified a fourth decision step (S 29 ), wherein a second decision corresponding to said second driving command (PILS) is taken corresponding to said oversampled stream being scrolled down. In one embodiment, if said third condition is not verified, the method further comprises: a fifth counting step (S 30 ), wherein said fifth counter (J) is incremented and after which the method returns to said seventh verify step (S 20 ). In one embodiment, each time a decision step is executed (S 21 , S 25 , S 27 , S 29 ), then the method returns to said fifth verify step (S 15 ) and said fifth counter (J) is set to 1. In one embodiment, a clock and data recovery device ( 1 ) comprises at least a first input terminal (IN) receiving an input data stream (IDS) at a data rate and a second input terminal (INck) receiving a reference clock signal (CK) at a clock rate, as well as a first output terminal (OUTrd) providing a recovered data signal (RDATA), a second output terminal (OUTrc) providing a recovered clock signal (RCK), an oversampling portion ( 2 ) comprising at least a serial-to-parallel converter ( 4 ) having a first input terminal (IN 4 ) connected to said first input terminal (IN) of said clock and data recovery device ( 1 ), thus receiving said input data stream (IDS), a second input terminal (IN 4 ck ) connected to said second input terminal (INck) of said clock and data recovery device ( 1 ), thus receiving said reference clock signal (CK) and a parallel output (PO[i], i=1 . . . N), the first input bit of a current word of said input data stream (IDS) being at the N-th output terminal (PO[N]) and the N-th input bit of a current word of said input data stream (IDS) being at the first output terminal (PO[1]), a central output terminal (PO[N/2-1]) being connected to said first output terminal (OUTrd) of said clock and data recovery device ( 1 ) and providing said recovered data signal (RDATA) at said data rate, said clock rate being higher than said data rate; and a tracking portion ( 3 ) comprising at least divider ( 5 ) connected to a detection and decision block ( 7 ), said divider ( 5 ) having at least a first input terminal (IN 5 ck ) connected to said second input terminal (INck) of said clock and data recovery device ( 1 ) and receiving said reference clock signal (CK) and an output terminal (OUT 5 ) connected to said second output terminal (OUTrc) of said clock and data recovery device ( 1 ) and providing said recovered clock signal (RCK), said detection and decision block ( 7 ) having a parallel input (PI[i], i=1 . . . N) connected to the parallel output terminals (PO[i]) of said serial-to-parallel converter ( 4 ) of said oversampling portion ( 2 ). In one embodiment, said output terminal (OUT 5 ) of said divider ( 5 ) of said tracking portion ( 3 ) is further connected to said serial-to-parallel converter ( 4 ) of said oversampling portion ( 2 ). In one embodiment, said detection and decision block ( 7 ) comprises a detection block ( 7 A) and a decision block ( 7 B) connected to each other, said detection block ( 7 A) having said parallel input (PI[i], i=1 . . . N) connected to said parallel output (PO[i], i=1 . . . N) of said serial-to-parallel converter ( 4 ) and said decision block ( 7 B) has a first and second output terminals (OUT 7 , OUT 7 *), connected to respective first and second input terminals (IN 5 , IN 5 *) of said divider ( 5 ) and providing thereto respective first and second driving signals (SLIP, PILS), which change a dividing ratio of said divider ( 5 ) of +1 and −1, respectively. In one embodiment, said first and second driving signals (SLIP, PILS) drive said serial-to-parallel converter ( 4 ) in order to move and keep a no transition area wherein no transitions between adjacent samples are found in the middle of said parallel output (PO[i], i=1 . . . N). In one embodiment, said serial-to-parallel converter ( 4 ) of said oversampling portion ( 2 ) comprises a hold portion ( 4 A) to store a last input bit of a previous input data stream, said hold portion ( 4 A) having a further output terminal (PO[N+1]) wherein a last input bit of a previous word of said input data stream (IDS) is provided at the same time of the N input bits of a current input data stream (IDS) and which is connected to a further input terminal (PI[N+1]) of said detection and decision block ( 7 ). In one embodiment, a clock and data recovery device comprises: a serial-to-parallel converter configured to oversample an input data stream at a reference clock rate higher than a data rate of the input data stream and having a number of parallel outputs for a current data word; and a tracking module coupled to the number of parallel outputs of the serial-to-parallel converter and configured to produce a recovered clock signal for the input data stream and to generate a control signal to cause the serial-to-parallel converter to provide a recovered data signal on an output of the number of parallel outputs. In one embodiment, the clock and data recovery device further comprises: an input to receive a reference clock signal coupled to the serial-to-parallel converter and the tracking circuit. In one embodiment, the tracking module comprises a divider configured to receive the reference clock signal and to provide the control signal to the serial-to-parallel converter. In one embodiment, the serial-to-parallel converter has an output for a last input bit of a previous word coupled to the tracking module; and the output providing the recovered data signal is a middle output in the number of parallel outputs. In one embodiment, the tracking module is configured to: detect transitions between adjacent samples provided by the serial-to-parallel converter; and selectively change a dividing ratio of the divider based on the detection of a transition. In one embodiment, the control signal causes the serial-to-parallel converter to maintain a no-transition window on outputs in the number of parallel outputs adjacent to the output providing the recovered data signal. In one embodiment, a system comprises: a reference clock configured to generate a reference clock signal; a serial-to-parallel converter configured to oversample an input data stream using the reference clock signal and having a number of parallel outputs for a current data word; and a tracking module coupled to the number of parallel outputs of the serial-to-parallel converter and configured to produce a recovered clock signal for the input data stream and to generate a control signal to cause the serial-to-parallel converter to provide a recovered data signal on a middle output of the number of parallel outputs, the reference clock signal having a frequency higher than a data rate of the input data stream. In one embodiment, the tracking module comprises a divider configured to receive the reference clock signal and to provide the control signal to the serial-to-parallel converter. In one embodiment, the serial-to-parallel converter has an output for a last input bit of a previous word coupled to the tracking module. In one embodiment, the tracking module is configured to: detect transitions between adjacent samples provided by the serial-to-parallel converter; and selectively change a dividing ratio of the divider based on the detection of a transition. In one embodiment, the control signal causes the serial-to-parallel converter to maintain a no-transition window on outputs in the number of parallel outputs adjacent to the middle output. In one embodiment, the reference clock signal frequency is equal to the number of parallel outputs multiplied by the data rate of the input data stream.
|
BACKGROUND 1. Technical Field The present disclosure relates to a clock and data recovery method and corresponding device. The description particularly, but not exclusively, relates to a clock and data recovery method for an ASIC chip designed for telecom/datacom applications and the following description is made with reference to this field of application for convenience of explanation only. 2. Description of the Related Art An ASIC (acronym from Application-Specific Integrated Circuit) is a chip designed for a particular application. It typically consists of a core logic, where the specific application is implemented, and an in/out interface, that connects the specific application to the overall system. An ASIC for telecom/datacom applications generally includes, as an input/output interface, a SERDES interface (serial-to-parallel/parallel-to-serial interface). Its goal is to adapt high speed serial data rate of a data line to a low speed parallel data rate of the chip core. Line data rate is linked to bandwidth requirements of communication systems and limited by technology. Core data rate is linked to the available technology (for instance, the CMOS technology presently used) in terms of both maximum operating frequencies and digital design tools. Apart from the individual trends of line and core data rates (the former growing up faster than the latter), new applications typically require a certain degree of back-compatibility with respect to old applications. Hence, an ASIC is generally able to treat a high data rate as well as a low data rate through the very same SERDES interface. It should be noted that the low data rate is usually an integer sub-rate of the high data rate. More particularly, for telecom/datacom applications in data transmission through ASICs, the reliability and the quality of a data link or generally of a communication line depends on the timing control. In addition, the transmission of a clock signal from one end to the other of a communication line in a telecom/datacom system is expensive, both because the clock signal is not a payload and because of technology limitations due to its bandwidth. Nowadays, the latter issue is usually solved in the field by double data rate interfaces. According to this solution, both the rising and the falling edges of the clock signal are used as reference events (in contrast with normal data rate interfaces where only one type of edge, the rising or falling one, of the clock signal is used as a reference event). In this way data and clock signals have the very same physical bandwidth. However, the known solutions are still affected by the former problem. Moreover, communication lines with a clock signal transmitted therethrough have strong timing budget requirements, which become harder and harder to meet when the data rate increases, since the bit period becomes smaller and smaller. The most popular way to control timing is by embedding a clock signal into the transmitted data and recovering the timing information at the receiver side of the communication line by means of a clock and data recovery device (CDR in the following). In particular, the CDR recovers the timing information based on the transitions of input data, under the assumption that the nominal bit period is constant, thus producing a recovered data signal as well as a recovered clock signal. Then, taking recovered data and clock signals from the CDR, a serial to parallel converter matches the line data rate and the core data rate. Traditionally, analog phase-locked loops (PLL) have been used to implement CDR devices. Although, in general, an analog PLL can operate at high frequencies, it suffers from problems such as, for instance, the frequency drift during long sequences of identical bits (also indicated as CID, Consecutive Identical Digits) and the difficult lock acquisition process (at the power on or after a loss of synchronization). Being a CDR using analog PLL a fully analog solution, high performances are expected, but they are paid in terms area and power consumption. Another drawback is a hardly portable design through technologies. CDRs of this kind are described in the following references: U.S. Pat. No. 4,949,051 issued on Aug. 14, 1990 to J. P. Viola and concerning a “Phase lock clock recovery with aided frequency acquisition”; “A monolithic 622 Mb/s clock extraction data retiming circuit”, Benny Lai, Richard C. Walker, ISSCC Dig. Tech. Papers, pp. 144-145, February 1991; and “An analog PLL-based clock and data recovery circuit with high input jitter tolerance” Sam Y. Sun, IEEE JSSC vol. SC-24, pp. 325-330, April 1989. Another approach to timing or clock recovery is the digital one. Here, the smallest possible analog front end is used to generate timing information that feeds a recovery algorithm. This algorithm is usually described and implemented using a high level language (VHDL). In this way, a certain degree of portability through technologies is possible as well as some area and power saving. On the other hand, it is difficult to obtain high performance devices. Digital timing recovery in a serial connection line is typically done by a CDR device in two ways that are by tracking and by oversampling. In a tracking CDR, an optimum sampling phase is chosen among a discrete set, by an appropriate algorithm, and the output data is the input data which is sampled by the selected sampling phase. CDRs of this kind are described in the following references: U.S. Pat. No. 5,812,619 issued on Sep. 22, 1998 to Runaldue and concerning a: “Digital phase lock loop and system for digital clock recovery”; “A tracking clock recovery receiver for 4-Gbps signaling”, J. Poulton, W. I. Dally, S. Tell, IEEE Micro Vol. 18 Issue 1, pp. 25-27, January/February 1998; and “A semi-digital delay-locked loop using an analog-based FSM”, W. Rhee, B. Parker, D. Friedman, IEEE Trans. on Cir. and Sys. II: E. B. Vol. 51 Issue: 11, pp. 635-639, November 2004. In an oversampling CDR, the input data are sampled by more than one phase at the same time and an algorithm takes the decision of which value has been sampled. CDRs of this kind are described in the following references: U.S. Pat. No. 6,611,219 issued on Aug. 26, 2003 to Lee et al. and concerning an: “Oversampling data recovery apparatus and method”; “A 1.0 Gbps CMOS oversampling data recovery circuit with fine delay generation method” J.-Y. Park, J. K. Kang, IEICE Trans. Fund. Vol. E83 No. 6, June 2000; and “A 0.5 um CMOS 4.0 Gb/s serial link transceiver with data recovery using oversampling”, C.-K. K. Yang, R. Farjad-Rad, M. A, Horowitz, IEEE JSSC Vol. 33 No. 5, May 1998. A strong difference between tracking and oversampling CDRs is that the former solution recovers the clock while the latter recovers the data. In other words, the output of a tracking CDR is a data-clock pair with a known phase relationship, while the output of an oversampling CDR is typically a data signal. The main drawbacks of the above described solutions are as follows: custom design is still rather dominant so technology portability is difficult; efforts and tradeoffs are required to cover wide data rate ranges; the scalability is more and more difficult with increasing data rate. The technical problem underlying the present description is that of providing a clock and data recovery method and corresponding device having structural and functional characteristics which allow to improve the scalability with different technologies and frequencies, in this way overcoming the limits which still affect the conventional methods and devices. BRIEF SUMMARY An embodiment of the present invention provides a clock and data recovery method and corresponding device able to mix the tracking and oversampling features using a serial-to-parallel converter that oversamples the input data and a divider that can be controlled to track input data. In one aspect, a clock and data recovery method comprises the following steps: an oversampling step wherein an oversampled stream of samples is generated from an input data stream (IDS) at a data rate by using reference clock signal (CK) at a clock rate, said clock rate being higher than said data rate, and a tracking step of said input data stream (IDS) realised by locating transitions between adjacent samples of said oversampled stream and by moving a no transition area within said oversampled stream wherein no transitions between adjacent samples are found, a recovered data signal (RDATA) being obtained as a central portion of said no transition area and a recovered clock signal (RCK) being obtained by dividing said reference clock signal (CK). In one embodiment, said tracking step uses a search window (SW) of a subset of said oversampled stream samples, centred with respect to said input data stream (IDS). In one embodiment, the method further comprises: a first search state, wherein said subset of oversampled stream samples corresponding to said search window (SW) are checked in order to find said no transition area; when said no transition area is found, the method switching into, a second track state, wherein said subset of oversampled stream samples corresponding to said search window (SW) are checked in order to verify that no transition occurs between adjacent samples, and analyzed in order to track the input data stream aligning accordingly to said reference clock signal (CK), the method coming back to said first search state when a transition occurs. In one embodiment, said first search state comprises: an initialising sequence (S1, S2, S3); a main loop (A), to count a number of times without any transition in said input data stream (IDS); a first auxiliary loop (B), to count a number of a first driving command (SLIP) with respect to a number of said oversampled stream samples; a second auxiliary loop (C), to verify whether a minimum eye aperture condition is verified or not; the method providing a first and second output conditions from said first search state corresponding to a change of state (TS, S7) and to an alarm for no eye aperture found (S14). In one embodiment, said main loop (A) comprises: a first verify step (S4), wherein a first condition (PO[N−k]= . . . =PO[k−1]) is checked; a first counting step (S5), wherein a first counter (SEARCH_CNT) is incremented; and a second verify step (S6), wherein it is located when said first counter (SEARCH_CNT) is equal to a first value (N_LOCK), the method changes from said main loop (A) to said first auxiliary loop (B) when said first condition is not verified and a transition occurs before said first value (N_LOCK) is reached. In one embodiment, in case said first counter (SEARCH_CNT) is equal to said first value (N_LOCK), the method further comprises a first assertion step (S7) wherein a first state parameter (LOCK) is asserted, said first counter (SEARCH_CNT) keeping count of how many times no transitions are found in said search window (SW). In one embodiment, said first counter (SEARCH_CNT) it is set equal to 0 and reset when it reaches said first value (N_LOCK), such value being equal to the number of times without transitions in order to assert said first state parameter (LOCK) and provide said first output condition corresponding to a first change of state (TS) to move the method from said first search state to said second track state. In one embodiment, said first auxiliary loop (B) comprises: a first searching step (S8), wherein said subset of oversampled stream samples is scrolled up starting from a central position of said search window (SW); a third verify step (S9), wherein it is verified when a second counter (SLIP_CNT) is equal to a count value (N−1); and a second counting step (S10), wherein said second counter (SLIP_CNT) is incremented, said second counter (SLIP_CNT) keeps count of how many scroll of said subset of oversampled stream samples have been taken, the method changes from said first auxiliary loop (B) to said second auxiliary loop (C) when said second counter (SLIP_CNT) is equal to said count value (N−1); otherwise the method returns to said first verify step (S4). In one embodiment, said second counter (SLIP_CNT) is set equal to 0, and reset at said count value (N−1) after said oversampled stream has been all scanned, N being the number of said samples. In one embodiment, said second auxiliary loop (C) comprises: a third counting step (S11), wherein a current width (N−2*k) of said search window (SW) is narrowed; and a fourth verify step (S12), wherein it is verified when said current width (N−2*k) is narrower than a boundary condition parameter (MIN_EYE_APE). In one embodiment, if said current width (N−2*k) of said search window (SW) is not narrower than said boundary condition parameter (MIN_EYE_APE), the method further comprises a first reset step (S13), wherein said second counter (SLIP_CNT) is set equal to 0 and the method goes back to said first verify step (S4) and otherwise, the method comprises a final assertion step (S14) wherein said driving parameter (NO_EYE) is asserted and said second output condition corresponding to an alarm for no eye aperture found is provided. In one embodiment, said current with (N−2*k) of said search window (SW) is set at an initial value (N−2*k0), and reset when said first or said second output condition is provided, while said boundary condition parameter (MIN_EYE_APE) defines a minimum eye aperture that can be detected in said input data stream (IDS) corresponding to said second output condition. In one embodiment, in said second track state, the method comprises a checking phase of transitions in a first and a second subset of oversampled stream samples by means of respective track vectors (VU, VD) in order to decide whether said oversampled stream is to be not scrolled, scrolled up or scrolled down, a length (TW) of said track vectors (VU, VD) being programmable, said track vectors (VU, VD) latching the transitions within said first and second subset of oversampled stream samples, said checking phase being recursive. In one embodiment, said second track state comprises: an initialising sequence; a first waiting loop (D), where nothing is done for N_WAIT cycles of an oversampling clock; a check and assertion sequence (S18, S19, SS) wherein a third output condition corresponding to a second change of state (SS) from the said track state to said search state is provided; a second tracking loop (E), where said track vectors are analyzed in order to take a proper decision to track said input data stream (IDS). In one embodiment, said first waiting loop (D) of said second track state comprises: a fifth verify step (S15), wherein a fourth counter (W_CNT) of cycles of said oversampling clock is compared with a parameter (N_WAIT) that defines a waiting time and that is programmable; and a fourth counting step (S16), wherein said fourth counter (W_CNT) is incremented. In one embodiment, said fifth verify step (S15) is substituted by a counting step wherein said transitions are separately counted for each samples of said oversampled stream. In one embodiment, the clock and data recovery method further comprises: a second reset step (S17), wherein said counter (W_CNT) is set equal to 0 once it has reached a value equal to said parameter (N_WAIT) that defines a waiting time; a sixth verify step (S18), wherein said subset of oversampled stream samples corresponding to said search window (SW) are checked in order to find out if a transition has occurred; and in case a transition has occurred in said search window (SW), the method further comprises a third assertion step (S19) wherein a second state parameter (UNLOCK) is asserted and said third output condition corresponding to a second change of state (SS) to move the method from said second track state to said first search state is provided, otherwise, the method changes from said first waiting loop (D) to said second tracking loop (E). In one embodiment, said second tracking loop (E) comprises: a seventh verify step (S20), wherein a fifth counter (J) is compared with said length (TW) of said track vectors (VU, VD) and if the value of said fifth counter (J) is equal to said length (TW), then said fifth counter (J) is set to 1 and the method further comprises: a fourth assertion step (S21), wherein a third state parameter (NO_TRAN) is asserted; and a first decision step (S22), wherein first and second driving commands (SLIP/PILS) are kept on hold (DO_NOTHING). In one embodiment, if the value of said fifth counter (J) is not equal to said length (TW), the method further comprises: a fifth assertion step (S23), wherein a fourth state parameter (TRAN) is asserted; and an eighth verify step (S24), wherein it is checked a first condition corresponding to whether the j-th bits of said track vectors (VU, VD) are both equal to 1 (VU[j]=VD[j]=1) or not. In one embodiment, if said first condition is verified, then the method further comprises: a second decision step (S25), wherein said first and second driving commands (SLIP/PILS) are kept on hold (DO_NOTHING); otherwise, the method comprises: a ninth verify step (S26), wherein it is checked a second condition corresponding to whether or not the j-th bit of said first track vector (VU) is equal to 1 and the j-th bit of said second track vector (VD) is equal to 0 (VU[j]=1; VD[j]=0) and, is said second condition is verified, a third decision step (S27), wherein a first decision corresponding to said first driving command (SLIP) is taken corresponding to said oversampled stream being scrolled up. In one embodiment, if said second condition is not verified, the method further comprises: a tenth verify step (S28), wherein it is checked a third condition corresponding to whether or not the j-th bit of said first track vector (VU) is equal to 0 and the j-th bit of said second track vector (VD) is equal to 1; and, if said third condition is verified a fourth decision step (S29), wherein a second decision corresponding to said second driving command (PILS) is taken corresponding to said oversampled stream being scrolled down. In one embodiment, if said third condition is not verified, the method further comprises: a fifth counting step (S30), wherein said fifth counter (J) is incremented and after which the method returns to said seventh verify step (S20). In one embodiment, each time a decision step is executed (S21, S25, S27, S29), then the method returns to said fifth verify step (S15) and said fifth counter (J) is set to 1. In one embodiment, a clock and data recovery device (1) comprises at least a first input terminal (IN) receiving an input data stream (IDS) at a data rate and a second input terminal (INck) receiving a reference clock signal (CK) at a clock rate, as well as a first output terminal (OUTrd) providing a recovered data signal (RDATA), a second output terminal (OUTrc) providing a recovered clock signal (RCK), an oversampling portion (2) comprising at least a serial-to-parallel converter (4) having a first input terminal (IN4) connected to said first input terminal (IN) of said clock and data recovery device (1), thus receiving said input data stream (IDS), a second input terminal (IN4ck) connected to said second input terminal (INck) of said clock and data recovery device (1), thus receiving said reference clock signal (CK) and a parallel output (PO[i], i=1 . . . N), the first input bit of a current word of said input data stream (IDS) being at the N-th output terminal (PO[N]) and the N-th input bit of a current word of said input data stream (IDS) being at the first output terminal (PO[1]), a central output terminal (PO[N/2-1]) being connected to said first output terminal (OUTrd) of said clock and data recovery device (1) and providing said recovered data signal (RDATA) at said data rate, said clock rate being higher than said data rate; and a tracking portion (3) comprising at least divider (5) connected to a detection and decision block (7), said divider (5) having at least a first input terminal (IN5ck) connected to said second input terminal (INck) of said clock and data recovery device (1) and receiving said reference clock signal (CK) and an output terminal (OUT5) connected to said second output terminal (OUTrc) of said clock and data recovery device (1) and providing said recovered clock signal (RCK), said detection and decision block (7) having a parallel input (PI[i], i=1 . . . N) connected to the parallel output terminals (PO[i]) of said serial-to-parallel converter (4) of said oversampling portion (2). In one embodiment, said output terminal (OUT5) of said divider (5) of said tracking portion (3) is further connected to said serial-to-parallel converter (4) of said oversampling portion (2). In one embodiment, said detection and decision block (7) comprises a detection block (7A) and a decision block (7B) connected to each other, said detection block (7A) having said parallel input (PI[i], i=1 . . . N) connected to said parallel output (PO[i], i=1 . . . N) of said serial-to-parallel converter (4) and said decision block (7B) has a first and second output terminals (OUT7, OUT7*), connected to respective first and second input terminals (IN5, IN5*) of said divider (5) and providing thereto respective first and second driving signals (SLIP, PILS), which change a dividing ratio of said divider (5) of +1 and −1, respectively. In one embodiment, said first and second driving signals (SLIP, PILS) drive said serial-to-parallel converter (4) in order to move and keep a no transition area wherein no transitions between adjacent samples are found in the middle of said parallel output (PO[i], i=1 . . . N). In one embodiment, said serial-to-parallel converter (4) of said oversampling portion (2) comprises a hold portion (4A) to store a last input bit of a previous input data stream, said hold portion (4A) having a further output terminal (PO[N+1]) wherein a last input bit of a previous word of said input data stream (IDS) is provided at the same time of the N input bits of a current input data stream (IDS) and which is connected to a further input terminal (PI[N+1]) of said detection and decision block (7). In one embodiment, a clock and data recovery device comprises: a serial-to-parallel converter configured to oversample an input data stream at a reference clock rate higher than a data rate of the input data stream and having a number of parallel outputs for a current data word; and a tracking module coupled to the number of parallel outputs of the serial-to-parallel converter and configured to produce a recovered clock signal for the input data stream and to generate a control signal to cause the serial-to-parallel converter to provide a recovered data signal on an output of the number of parallel outputs. In one embodiment, the clock and data recovery device further comprises: an input to receive a reference clock signal coupled to the serial-to-parallel converter and the tracking circuit. In one embodiment, the tracking module comprises a divider configured to receive the reference clock signal and to provide the control signal to the serial-to-parallel converter. In one embodiment, the serial-to-parallel converter has an output for a last input bit of a previous word coupled to the tracking module; and the output providing the recovered data signal is a middle output in the number of parallel outputs. In one embodiment, the tracking module is configured to: detect transitions between adjacent samples provided by the serial-to-parallel converter; and selectively change a dividing ratio of the divider based on the detection of a transition. In one embodiment, the control signal causes the serial-to-parallel converter to maintain a no-transition window on outputs in the number of parallel outputs adjacent to the output providing the recovered data signal. In one embodiment, a system comprises: a reference clock configured to generate a reference clock signal; a serial-to-parallel converter configured to oversample an input data stream using the reference clock signal and having a number of parallel outputs for a current data word; and a tracking module coupled to the number of parallel outputs of the serial-to-parallel converter and configured to produce a recovered clock signal for the input data stream and to generate a control signal to cause the serial-to-parallel converter to provide a recovered data signal on a middle output of the number of parallel outputs, the reference clock signal having a frequency higher than a data rate of the input data stream. In one embodiment, the tracking module comprises a divider configured to receive the reference clock signal and to provide the control signal to the serial-to-parallel converter. In one embodiment, the serial-to-parallel converter has an output for a last input bit of a previous word coupled to the tracking module. In one embodiment, the tracking module is configured to: detect transitions between adjacent samples provided by the serial-to-parallel converter; and selectively change a dividing ratio of the divider based on the detection of a transition. In one embodiment, the control signal causes the serial-to-parallel converter to maintain a no-transition window on outputs in the number of parallel outputs adjacent to the middle output. In one embodiment, the reference clock signal frequency is equal to the number of parallel outputs multiplied by the data rate of the input data stream. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS In such drawings: FIG. 1 schematically shows a system with a clock and data recovery device realised according to an embodiment. FIG. 2A represents the parallel output of the oversampling portion of FIG. 1 with respect to an input data stream; it also shows the variables for a recovery algorithm. FIG. 2B represents the connection from the oversampling portion to the tracking portion of FIG. 1; it also shows the generation of the variables for the recovery algorithm. FIG. 3 shows a top level state diagram of the method according to an embodiment. FIG. 4 shows a more detailed state diagram of the method according to an embodiment in a first state. FIG. 5 schematically shows a more detailed state diagram of the method according to an embodiment in a second state. FIG. 5A schematically shows an internal portion of the block diagram of FIG. 5. FIG. 6 schematically plots internal signals of the clock and data recovery device of FIG. 1. DETAILED DESCRIPTION FIG. 1 shows a system 100 including a clock and data recovery device 1. The clock and data recovery device 1 comprises an oversampling portion 2 and a tracking portion 3, duly mixed in order to provide the desired recovery of the clock and data signals from a signal transmitted through a connection line. More particularly, an input data stream IDS is applied to a first input terminal IN of the clock and data recovery device 1, a recovered data signal RDATA being issued to a first output terminal OUTrd thereof. The clock and data recovery device 1 also has a second input terminal INck receiving a reference clock signal CK and a second output terminal OUTrc issuing a recovered clock signal RCK. More in detail, the oversampling portion 2 comprises a serial-to-parallel converter 4 in turn including a hold portion 4A and having a first input terminal IN4 connected to the first input terminal IN of the clock and data recovery device 1, thus receiving the input data stream IDS, and a second input terminal IN4ck connected to the second input terminal INck of the clock and data recovery device 1, thus receiving a reference clock CK, the reference clock CK being N times faster than the input data stream IDS, where N is an even integer. In other words, if the data rate of the input data stream IDS is fbit [Mbit/sec], the reference clock CK frequency is N*fbit [MHz]. The serial-to-parallel converter 4 also has a plurality of parallel output terminals, PO[N], . . . , PO[1], globally indicated as a parallel output PO[i], the first input bit of a current word of the input data stream IDS being at the output terminal PO[N] and the N-th input bit of the current word of the input data stream IDS being at the output terminal PO[1]. N is also the width of the parallel output PO[i]. The serial-to-parallel converter 4 is also indicated as SIPO (Serial In Parallel Out). A central output terminal PO[N/2+1] is connected to the first output terminal OUTrd of the clock and data recovery device 1, wherein the recovered data signal RDATA is provided, having a rate equal to the data rate fbit. The serial-to-parallel converter 4 realises an oversampling of the input data stream IDS at a rate equal to N*fbit. It should be noted that the above indicated relationship between data rate fbit and clock frequency N*fbit as well as the even parity for N is not binding and it is here considered only for the sake of convenience and simplicity. The serial-to-parallel converter 4 has a further output terminal PO[N+1] in correspondence of its hold portion 4A, wherein a last input bit of a previous word of the input data stream IDS is provided at the same time of the N input bits of the current input data stream IDS, for looking for transitions over N bits. Moreover, the tracking portion 3 comprises a divider 5 having a first input terminal IN5ck connected to the second input terminal INck of the clock and data recovery device 1 and receiving the reference clock signal CK, as well as a second and third input terminals, IN5 and IN5*, connected to respective output terminals, OUT7 and OUT7*, of a detection and decision block 7, also included in the tracking portion 3. The divider 5 also has an output terminal OUT5 connected to the serial-to-parallel converter 4 as well as to the second output terminal OUTrc of the clock and data recovery device 1, wherein the recovered clock RCK is provided. The recovered clock RCK is provided by the divider 5 and it is a divided signal having a rate which is equal to the data rate fbit. The detection and decision block 7 comprises a detection block or detector 7A and a decision block 7B connected to each other, the detection block 7A having a plurality of parallel input terminals PI[N+1], . . . , PI[1], globally indicated as a parallel input PI[i], connected to the parallel output PO[i] of the serial-to-parallel converter 4. Moreover, the decision block 7B has the first and second output terminals, OUT7 and OUT7*, connected to the divider 5 and providing thereto a first driving signal SLIP and a second driving signal PILS, which change a dividing ratio of the divider 5 of +1 and −1, respectively. The clock and data recovery device 1 implements a clock and data recovery method which comprises essentially an oversampling and a tracking step, as explained in the following. The oversampling step is performed by the oversampling portion 2 using the serial-to-parallel converter 4 which receives the reference clock CK and produce a plurality of samples forming an oversampled stream of the input data stream IDS, in particular, at the parallel output PO[i] of the serial-to-parallel converter 4, being its length equal to a bit period of the input data stream IDS itself. Each parallel output terminal thus provides a sample of the input data stream IDS. Moreover, advantageously according to the invention, the tracking step of the input data stream IDS is then performed by the tracking portion 3. Timing or clock information for the decision block 7B of the tracking portion 3 is obtained in terms of transitions between adjacent samples provided by the serial-to-parallel converter 4 of the oversampling portion 2 at its parallel output PO[i], such transitions being detected by the detection block 7A. Moreover, the decision block 7B controls the divider 5 of the tracking portion 3, by changing its dividing ratio of ±1 (thanks to the SLIP/PILS driving signals), in order to move and keep a no transition area in the middle of the parallel output PO[i] (central output PO[N/2+1]), i.e., an area wherein no transitions between adjacent samples are found. The recovered data signal RDATA is thus obtained at the central output PO[N/2+1] of the serial-to-parallel converter 4 of the oversampling portion 2, while the recovered clock signal RCK is obtained at the output OUT5 of the divider 5 of the tracking portion 3. Note that the input data stream IDS is not actually serial-to-parallel converted by the clock and data recovery device 1. In order to better understand the working of the clock and data recovery device 1 according to an embodiment, reference is made to FIG. 2A, showing the parallel output PO[i] of the serial-to-parallel converter 4 of the oversampling portion 2. As shown in FIG. 2A, it can be seen that the parallel output PO[i] covers one unit interval (1 UI=1 Tbit=1/fbit) of an input data stream IDS at the input data rate fbit, in the example shown in the figure comprising N samples. Consequently, each parallel output terminal PO[1] . . . PO[N] covers 1/N UI (i.e., one sample) at the input data rate fbit or 1 UI at the oversampling rate N*fbit. FIG. 2B shows how the input data stream IDS is analyzed in order to generate variables for the recovery algorithm. In detail, the logic values at adjacent parallel output terminals of the serial-to-parallel converter 4 are tested (for instance, through exclusive-or or XOR logic function). As it will be clear in the following, information from a central range of output terminals is used during both a first or SEARCH state and a second or TRACK state (Search Window SW), while information from the boundary terminals is used during the TRACK state (in particular, by Track Vectors, as explained hereinafter). The Search Window has a programmable starting width; its current width can be narrowed down to 2 UI at the oversampling rate according to the recovery algorithm, i.e., according to the actual input data stream IDS. Track Vectors, VU and VD, are used by the recovery algorithm to drive the signals SLIP and PILS in the proper way and have the same length that is programmable. The clock and data recovery method of an embodiment comprises the following states: the SEARCH state, wherein the samples at the parallel output terminals of the serial-to-parallel converter 4 corresponding to the Search Window SW are checked in order to find a no transition area that is an eye aperture of the input data stream IDS wherein no transitions between adjacent samples are found. The starting width of the Search Window SW can be narrowed down to 2 UI at the oversampling rate that is the minimum operating eye aperture of the input data stream IDS. It should be noted that the data recovery method as above explained does not work when the eye aperture of the input data stream IDS is less than 2 UI at the oversampling rate. Once such no transition area is found, the method switches to the TRACK state, wherein the samples at the parallel output terminals of the serial-to-parallel converter 4 corresponding to the search window SW are checked; if a transition is found then the method switches to the SEARCH state otherwise it stays in the TRACK state. At the same time, the parallel output terminals of the serial-to-parallel converter 4 corresponding to the track vectors VU and VD are checked in order to obtain the driving signals SLIP and PILS so that the input data stream IDS is tracked. FIG. 3 represents a top level state diagram of a method 300 according to an embodiment. At the power on, the working state of the method is the SEARCH state. The working state becomes the second or TRACK state when the current search window SW has no transition for N_LOCK times (N_LOCK may be programmable). If the previous condition is not satisfied, then the working state does not change. Details about the SEARCH state are given later on. During the TRACK state, a single transition which is found in the current search window SW changes the working state to the SEARCH state. The working state remains the TRACK state as far as no transition is found in the current search window SW. Details about the TRACK state are given later on. The state diagram of FIG. 3 comprises a first command gotoT, which corresponds to a first condition PO[N−k]= . . . =PO[k−1], N_LOCK times, and a second command stayT, which corresponds to a second condition PO[N−k]= . . . =PO[k−1], wherein PO[N−k], . . . , PO[k−1] is the current search window SW and N_LOCK is the number of checks without any transition in the search window SW. A single transition in the search window SW makes the state changing from the TRACK state to the SEARCH state. This condition is opposite to the second condition PO[N−k]= . . . =PO[k−1] (command NOT(stayT) in FIG. 3). On the other hand, as far as the first condition PO[N−k]= . . . =PO[k−1] is not verified, the state is the SEARCH state (command NOT(gotoT) in FIG. 3]. A flow diagram of an embodiment of a clock and data recovery method 400 in the SEARCH state is shown in FIG. 4. The clock and data recovery method in the embodiment of the SEARCH state comprises: an initialising sequence (steps S1, S2, S3); a main loop “A”, to count the number of times without any transition in the input data stream IDS (steps S4, S5, S6); a first auxiliary loop “B”, to count the number of SLIP commands with respect to the number of parallel outputs PO[i] (steps S8, S9, S10); a second auxiliary loop “C”, to verify whether the minimum eye aperture condition is verified or not (steps S11, S12, S13); the method providing a first and second output conditions of this SEARCH state corresponding to a change of state (steps TS, S7) and to an alarm for no eye aperture found (step S14). In detail, the method 400 comprises the following steps: a start step S1; a first initialising step S2, wherein a set of registers is reset; a second initialising step S3, wherein a set of parameters is set; a first verify step S4, wherein the first condition PO[N−k]= . . . =PO[k−1] is checked; a first counting step S5, wherein a first counter SEARCH_CNT is incremented; a second verify step S6, wherein it is located when the first counter SEARCH_CNT is equal to a first value N_LOCK. In case the first counter SEARCH_CNT is equal to the first value N_LOCK, the method further comprises a first assertion step S7 wherein a first state parameter LOCK is asserted and a first output condition TS (change of state) to the TRACK state is provided. The first counter SEARCH_CNT keeps count of how many times no transitions are found in the search window SW and it is set equal to 0 and reset when it reaches the first value N_LOCK, such value being equal to the number of times without transitions in order to assert the first state parameter LOCK and move from the search state to the track state (first output condition or change of state TS). If a transition occurs before the first value N_LOCK is reached, i.e., when the first condition PO[N−k]= . . . =PO[k−1], N_LOCK times, is not verified, the method further comprises the following steps: a first searching step S8, wherein the parallel output PO[i] is scrolled up (decision block 7B providing a first driving signal SLIP); a third verify step S9, wherein it is verified when a second counter SLIP_CNT is equal to a count value N−1; and a second counting step S10, wherein the second counter SLIP_CNT is incremented. The method then return to the first verify step S4. The second counter SLIP_CNT keeps count of how many SLIP commands have been provided or scroll up decisions have been taken; it is set equal to 0, and reset when it reaches the value N−1 (i.e., after the whole parallel output PO[i] has been scrolled up), N being the number of parallel output PO[i] of the serial-to-parallel converter 4 and the oversampling ratio (even number). If the parallel output PO[i] has been scrolled up N times, i.e., when the second counter SLIP_CNT is equal to the count value N, then the method comprises the following steps: a third counting step S11, wherein a current width N−2*k of the search window SW is narrowed; and a fourth verify step S12, wherein it is verified when the current width N−2*k of the search window SW is narrower than a boundary condition parameter MIN_EYE_APE. If the current width N−2*k of the search window SW is not narrower than the boundary condition parameter MIN_EYE_APE, the method further comprises a first reset step S13, wherein the second counter SLIP_CNT is set equal to 0 and the method goes back to the first verify step S4. Otherwise, the method comprises a second assertion step S14 wherein the driving parameter NO_EYE is asserted. In particular, the initial width N−2*k0 of the search window SW is set by an initial value k0 of a k counter, being 0<k0<{N−MIN_EYE_APE}/2 and the k counter reset when an output condition, corresponding to the first output condition TS and to the first assertion step S7 or the final assertion step S14, is reached from the SEARCH state. On the other hand, the boundary condition parameter MIN_EYE_APE defines the minimum eye aperture that can be detected in the input data stream IDS and, so, it defines the second output condition of the final assertion step S14 that is whether the current width N−2*k of the search window SW is less than the minimum eye aperture, i.e., the boundary condition parameter MIN_EYE_APE. It should be noted that the embodiment of the method 400 in the search state comprises three loops: a main loop A corresponding to a number of times without any transition; a first auxiliary loop B corresponding to a number of SLIP signal pulses against number of samples at the parallel output PO[i]; and a second auxiliary loop C corresponding to a minimum value of the eye aperture of the input data stream IDS. To summarize, in the main loop A, the current search window SW, consisting of the parallel outputs PO[N−k], . . . , PO[k−1], is checked. If no transitions are detected by the detection block 7A for N_LOCK consecutive times, then the method moves to the TRACK state (first output condition TS) and the first state parameter LOCK is asserted. If a transition occurs before the first value N_LOCK is reached, then the parallel output PO[i] is scrolled up (decision block 7B providing a first driving signal SLIP). If the parallel output PO[i] has been scrolled up N times, then the current width of the search window SW is narrowed and the SEARCH state restarts, the method being in the first auxiliary loop B. If the current width of the search window SW is narrower than the boundary condition parameter MIN_EYE_APE, then the driving parameter NO_EYE is asserted, the method being in the second auxiliary loop C. A flow diagram of an embodiment of a clock and data recovery method 500 in the second or TRACK state is shown in FIG. 5. During the TRACK state, the whole parallel output PO[i] is checked in order to perform different operations. If a transition occurs in the search window SW, then the method changes to the first or SEARCH state. Otherwise, a first and a second portions of the parallel output PO[i], by means of respective track vectors, indicated as VU[TW−1:0] and VD[TW−1:0], and generated by the output terminals from PO[N+1] to PO[N−TW] and from PO[TW] to PO[1] respectively, are checked in order to decide which action has to be taken in order to follow (i.e., to track) any input phase variation or transition, the length TW of the track vectors VU and VD may be programmable. A decision is one of the following: a first or DO_NOTHING decision, which means “continue dividing by N”; a second or SLIP decision, which means “divide by N+1 for 1 UI at the oversampling rate”; and a third or PILS decision, which means “divide by N−1 for 1 UI at the oversampling rate”. Accordingly, the parallel output PO[i] is not scrolled, scrolled up (as shown by the arrow SLIP in FIG. 1) or scrolled down (as shown by the arrow PILS in FIG. 1). As an example, considering N=10, k0=2 and TW=3, the starting width of the search window SW is 10−2*2=6 UI at the oversampling rate, while the track vectors are VU[2:0] and VD[2:0]. In detail, for the track vector VU, VU[2] latches a first transition occurring between parallel outputs PO[11:10], VU[1] latches a first transition occurring between parallel outputs PO[10:9] and VU[0] latches a first transition occurring between parallel outputs PO[9:8]. On the other hand, for the track vector VD, VD[2] latches a first transition occurring between parallel outputs PO[2:1], VD[1] latches a first transition occurring between parallel outputs PO[3:2] and VD[0] latches a first transition occurring between parallel outputs PO[4:3]. In a general manner, the track vectors latch the transitions according to the following sets of equation: TRACK VECTOR, VU[TW−1:0]: VU[TW−1]=1 when PO[N+1]!=PO[N] VU[TW−2]=1 when PO[N]!=PO[N−1] (and so on up to VU[0]) and TRACK VECTOR, VD[TW−1:0]: VD[TW−1]=1 when PO[2]!=PO[1] VD[TW−2]=1 when PO[2]!=PO[2] (and so on up to VD[0]) In order to perform the above referred actions, an embodiment of the method 500 of the TRACK state comprises: an initialising sequence (steps S1, S2, S3); a first or waiting loop “D”, where nothing is done for N_WAIT cycles of the oversampling clock (steps S15, S16, S17); a check and assertion sequence (steps S18, S19, SS) wherein a third output condition from the TRACK state to the SEARCH state is provided; a second or tracking loop “E”, where the track vectors are analyzed in order to take the proper decision to track the input data stream IDS (steps from S20 to S30]. In detail, apart from the initialising sequence, the method 500 comprises the following steps: a fifth verify step S15, wherein a fourth counter W_CNT of cycles of the oversampling clock is compared with the parameter N_WAIT that defines the waiting time; a fourth counting step S16, wherein the counter W_CNT is incremented and after which the method returns to the fifth verify step S15; and a second reset step S17, wherein the counter W_CNT is set equal to 0 once it has reached the value N_WAIT. In this way, the waiting loop “D” is done, which lasts N_WAIT cycles of the oversampling clock (N-WAIT may be a programmable parameter), before entering the reminder of method 500 that includes the steps from S18 to S30. Then, the method comprises: a sixth verify step S18, wherein the central positions of the parallel output PO[i], corresponding to the search window SW, are checked in order to find out if a transition has occurred among the corresponding samples. In case at least one transition has occurred in the search window SW, the method further comprises: a third assertion step S19, wherein a second state parameter UNLOCK is asserted and the third output condition or change of state SS to move from the TRACK state to the SEARCH state is provided. Otherwise, when no transition is found in the search window SW, the method enters into the tracking loop “E”, where the track vectors VU and VD are scanned in order to decide which action has to be taken. In detail, the tracking loop “E” comprises: a seventh verify step S20, wherein a fifth counter J is compared with the length of the track vectors TW. If the value of the counter J is TW, then the counter J is set to 1 and the method comprises: a fourth assertion step S21, wherein a third state parameter NO_TRAN is asserted; and a first decision step S22, wherein the SLIP/PILS pair is kept on hold (DO_NOTHING). Otherwise, when the value of the counter J is less than TW, the method comprises: a fifth assertion step S23, wherein a fourth state parameter TRAN is asserted; and an eighth verify step S24, wherein it is checked whether the j-th bits of the track vectors VU and VD are both equal to 1 or not; if the condition VU[j]=VD[ ]=1 is satisfied, then a second decision step S25 is entered, wherein the SLIP/PILS pair is kept on hold (DO_NOTHING); otherwise, a ninth verify step S26 is entered, wherein it is checked whether or not the j-th bit of the track vector VU is equal to 1 and the j-th bit of the track vector VD is equal to 0; if the condition VU[j]=1 and VD[j]=0 is satisfied, then a third decision step S27 is entered, wherein the SLIP decision is taken; otherwise, a tenth verify step S28 is entered, wherein it is checked whether or not the j-th bit of the track vector VU is equal to 0 and the j-th bit of the track vector VD is equal to 1; if the condition VU[j]=0 and VD[j]=1 is satisfied, then a fourth decision step S29 is entered, wherein the PILS decision is taken; otherwise, a fifth counting step S30 is entered, wherein the counter J is incremented and after which the method returns to the seventh verify step S20. It should be noted that each time a decision step is executed (S21, S25, S27, S29), then the method returns to the fifth verify step S15 and the J counter is set to 1. The scanning strategy of the track vectors VU and VD (steps from S20 to S30) can be described according to the following recursive algorithm: p_track_recursive{VU, VD, j} if j=TW then NO_TRAN/DO_NOTHING (S21) elseif VU[j]=1 & VD[j]=1 then DO_NOTHING (S24) elseif VU[j]=1 & VD[j]=0 then SLIP (S26) elseif VU[j]=0 & VD[j]=1 then PILS (S28) else p_track_recursive{VU, VD, j++} (condition VU[j]=0 & VD[j]=0) The scanning strategy of the track vectors VU and VD (steps from S20 to S30) is also described by the FIG. 5A. Instead of latching the transitions, it is also possible to count them separately for each position or output terminal. Hence, having a high degree of information about the statistics of the transitions in a tracked eye is attainable. In other words, a histogram of such tracked eye can be traced out. FIG. 6 shows relevant waveforms for the divider 5, wherein the effect of the SLIP/PILS action is outlined (in an example with N=10). The effect of a SLIP pulse input to the divider 5 in FIG. 1 is to make the output divided clock lag of one high frequency clock cycle. Similarly, the PILS pulse makes the output divided clock anticipate its edge of one high frequency clock cycle. In the previous description, it is assumed that, if the data rate is fbit [Mbit/sec], then the clock frequency is N*fbit [MHz], moreover N is also the width of the parallel output PO[i] of the serial-to-parallel converter 4. Actually, a different data rate can also be used, while preserving the same system-clock. In this case, only the dividing factor of the divider 5 inside the serial-to-parallel converter 4 has to be adjusted accordingly to the date rate. To give an example, maintaining generality, it can be said that the supported data rate can become (N/D)*fbit [Mbit/s], if the divider ratio is changed to D. Of course, in this case, the method has to read only the first D bits of the parallel output PO[i] of the serial-to-parallel converter 4. The high frequency clock is still N*fbit [MHz]. In summary, a method and a corresponding device of an embodiment have been described, which recover a clock and data from a transmitted signal or input data stream IDS, using a high speed reference clock CL. The high-speed reference clock has a frequency which is N times the frequency of the data. Oversampling is performed using demultiplexing, and selection logic is not required to recover the data signal. Embodiments of the proposed device exploit a 1 to N serial to parallel converter and a controlled divider to oversample and track an input data stream IDS. The tracking may be managed by instantaneously changing (±1) the dividing ratio of the divider 5, in order to move and keep a no-transition area in the middle of the parallel output PO[i] of the serial-to-parallel converter 4. Recovered data obtained at a central output PO[N/2-1] of the serial-to-parallel converter 4, while recovered clock is a divided clock issued from the divider 5 itself. Embodiments of the clock and data recovery method and corresponding device have several advantages, among which: inherently area saving structure (only a serial-to-parallel converter 4 is used); high frequency circuitry is limited to the divider 5; re-usability of existing serial-to-parallel converters or more relaxed performance of new ones for implementing the serial-to-parallel converter 4; easily scalable with data rate; and it is a cheap solution when back-compatibility to low data rates is required. The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
|
H
|
H04
|
H04L
|
7
|
00
|
|||
12001945
|
US20090152411A1-20090618
|
Adjustable support arm assembly
|
ACCEPTED
|
20090604
|
20090618
|
[]
|
A47F510
|
["A47F510"]
|
7641162
|
20071214
|
20100105
|
248
|
097000
|
96288.0
|
MARSH
|
STEVEN
|
[{"inventor_name_last": "Tsay", "inventor_name_first": "Wen-Feng", "inventor_city": "Taipei", "inventor_state": "", "inventor_country": "TW"}]
|
An adjustable support arm assembly includes a holder frame affixed to a support, a mounting frame for supporting an object, and a coupling structure coupled between the holder frame and the mounting frame. The coupling structure comprises a female coupling member, a male coupling member inserted into the female coupling member, a polygonal shaft with a peripherally toothed head inserted through the female coupling member and the male coupling member and movable between a locking position to lock the female coupling member to the male coupling member and an unlocking position for allowing turning of the female coupling member about the polygonal shaft relative to the male coupling member, and a compression spring that supports the polygonal shaft in the locking position.
|
1. An adjustable support arm assembly comprising: a holder frame affixed to a support; a mounting frame for supporting an object, a link, and two coupling structures respectively coupling two distal ends of said link to said holder frame and said mounting frame, said coupling structures each comprising: a female coupling member, said female coupling member comprising two circular coupling holes axially aligned and a toothed portion extending around one end of said circular coupling holes; a male coupling member, said male coupling member comprising a transversely extending polygonal coupling hole disposed between the two circular coupling holes of said female coupling member; a polygonal shaft inserted through the circular coupling holes of said female coupling member and fitted into the polygonal coupling hole of said male coupling member, said polygonal shaft having a peripherally toothed head movable with said polygonal shaft between a locking position where said peripherally toothed head is engaged with the toothed portion of said female coupling member to lock said female coupling member to said male coupling member and an unlocking position where said peripherally toothed head is disengaged from the toothed portion of said female coupling member for allowing turning of said female coupling member about said polygonal shaft relative to said male coupling member; a cap fixedly connected to one end of said polygonal shaft opposite to said peripherally toothed head; and a compression spring mounted on said polygonal shaft and stopped between said cap and said female coupling member to support said polygonal shaft in said locking position. 2. The adjustable support arm assembly as claimed in claim 1, further comprising a mounting assembly provided at a top side of said mounting frame for securing the object to be supported. 3. The adjustable support arm assembly as claimed in claim 1, wherein said link is comprised of a plurality of support arms connected in series. 4. An adjustable support arm assembly comprising: a holder frame affixed to a support; a mounting frame for supporting an object, and a coupling structure coupled between said holder frame and said mounting frame, said coupling structure comprising: a female coupling member, said female coupling member comprising two circular coupling holes axially aligned and a toothed portion extending around one end of said circular coupling holes; a male coupling member, said male coupling member comprising a transversely extending polygonal coupling hole disposed between the two circular coupling holes of said female coupling member; a polygonal shaft inserted through the circular coupling holes of said female coupling member and fitted into the polygonal coupling hole of said male coupling member, said polygonal shaft having a peripherally toothed head movable with said polygonal shaft between a locking position where said peripherally toothed head is engaged with the toothed portion of said female coupling member to lock said female coupling member to said male coupling member and an unlocking position where said peripherally toothed head is disengaged from the toothed portion of said female coupling member for allowing turning of said female coupling member about said polygonal shaft relative to said male coupling member; a cap fixedly connected to one end of said polygonal shaft opposite to said peripherally toothed head; and a compression spring mounted on said polygonal shaft and stopped between said cap and said female coupling member to support said polygonal shaft in said locking position.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a support arm assembly and more particularly, to an adjustable support arm assembly, which allows easy adjustment of the tilt angle. 2. Description of the Related Art A bracket or support arm assembly may be used and installed in a wall to hold a LCD TV, LCD monitor, satellite antenna, lighting fixture, video camera, advertising board, furniture, tool, etc. Conventional brackets or support arm assemblies for supporting an object on a wall do not allow the user to adjust the tilt angle of the object supported thereon. There are adjustable support arm assemblies that allow adjustment of the tilt angle of the object supported thereon. However, the adjustment procedure is complicated.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide an adjustable support arm assembly that allows easy adjustment of the tilt angle of the object supported thereon. According to the present invention, the adjustable support arm assembly comprises a holder frame affixed to a support, a mounting frame for supporting an object, a link, and two coupling structures respectively coupling two distal ends of the link to the holder frame and the mounting frame. Each coupling structure comprises a female coupling member, a male coupling member, a polygonal shaft, a cap, and a compression spring. The female coupling member comprises two circular coupling holes axially aligned, and a toothed portion extending around one end of the circular coupling holes. The male coupling member comprises a transversely extending polygonal coupling hole disposed between the two circular coupling holes of the female coupling member. The polygonal shaft is inserted through the circular coupling holes of the female coupling member and fitted into the polygonal coupling hole of the male coupling member, having a peripherally toothed head movable with the polygonal shaft between a locking position where the peripherally toothed head is engaged with the toothed portion of the female coupling member to lock the female coupling member to the male coupling member and an unlocking position where the peripherally toothed head is disengaged from the toothed portion of the female coupling member for allowing turning of the female coupling member about the polygonal shaft relative to the male coupling member. The cap is fixedly connected to one end of the polygonal shaft opposite to the peripherally toothed head. The compression spring is mounted on the polygonal shaft and stopped between the cap and the female coupling member to support the polygonal shaft in the locking position.
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support arm assembly and more particularly, to an adjustable support arm assembly, which allows easy adjustment of the tilt angle. 2. Description of the Related Art A bracket or support arm assembly may be used and installed in a wall to hold a LCD TV, LCD monitor, satellite antenna, lighting fixture, video camera, advertising board, furniture, tool, etc. Conventional brackets or support arm assemblies for supporting an object on a wall do not allow the user to adjust the tilt angle of the object supported thereon. There are adjustable support arm assemblies that allow adjustment of the tilt angle of the object supported thereon. However, the adjustment procedure is complicated. SUMMARY OF THE INVENTION The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide an adjustable support arm assembly that allows easy adjustment of the tilt angle of the object supported thereon. According to the present invention, the adjustable support arm assembly comprises a holder frame affixed to a support, a mounting frame for supporting an object, a link, and two coupling structures respectively coupling two distal ends of the link to the holder frame and the mounting frame. Each coupling structure comprises a female coupling member, a male coupling member, a polygonal shaft, a cap, and a compression spring. The female coupling member comprises two circular coupling holes axially aligned, and a toothed portion extending around one end of the circular coupling holes. The male coupling member comprises a transversely extending polygonal coupling hole disposed between the two circular coupling holes of the female coupling member. The polygonal shaft is inserted through the circular coupling holes of the female coupling member and fitted into the polygonal coupling hole of the male coupling member, having a peripherally toothed head movable with the polygonal shaft between a locking position where the peripherally toothed head is engaged with the toothed portion of the female coupling member to lock the female coupling member to the male coupling member and an unlocking position where the peripherally toothed head is disengaged from the toothed portion of the female coupling member for allowing turning of the female coupling member about the polygonal shaft relative to the male coupling member. The cap is fixedly connected to one end of the polygonal shaft opposite to the peripherally toothed head. The compression spring is mounted on the polygonal shaft and stopped between the cap and the female coupling member to support the polygonal shaft in the locking position. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of an adjustable support arm assembly according to the present invention. FIG. 2 is an exploded view of the adjustable support arm assembly shown in FIG. 1. FIG. 3 is a sectional view in an enlarged scale of FIG. 1. FIG. 4 is an elevational view of an alternate form of the adjustable support arm assembly according to the present invention. FIG. 5 is an exploded view of the adjustable support arm assembly shown in FIG. 4. FIG. 6 is a schematic sectional view of a clamping assembly for the adjustable support arm assembly according to the present invention. FIG. 7 corresponds to FIG. 6, showing the position of the clamping plate adjusted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the annexed drawings in detail, an adjustable support arm assembly in accordance with the present invention is shown comprised of a holder frame 1, a link 2, and a mounting frame 3. The holder frame 1 is adapted to support a LCD TV, LCD monitor, satellite antenna, lighting fixture, video camera, advertising board, furniture, tool, etc. The mounting frame 3 is for fastening to a wall panel or support means. The link 2 can be formed of one single bar or a number of support arms coupled together for connection between the holder frame 1 and the mounting frame 3. Male coupling members 5 and female coupling members 4 are respectively provided at the two distal ends of the link 2 and the bottom side of the holder frame 1 and the top side of the mounting frame 3. According to the embodiment shown in FIGS. 1˜3, a female coupling member 4 is respectively provided at the bottom side of the holder frame 1 and the bottom end of the link 2, and a male coupling member 5 is respectively provided at the top side of the mounting frame 3 and the top end of the link 2. According to the embodiment shown in FIGS. 4 and 5, one female coupling member 4 and one male coupling member 5 are respectively provided at the two distal ends of the shell 20 of the link 2. One male coupling member 5 is connectable to one associating female coupling member 4. After insertion of the male coupling member 5 into the associating female coupling member 4, a polygonal shaft 6 is inserted through the aligned and transversely extending circular coupling holes 41 of the female coupling member 4 and the transversely extending polygonal coupling hole 51 of the male coupling member 5 to pivotally secure the female coupling member 4 to the associating male coupling member 5. The polygonal shaft 6 has one end fixedly provided with a peripherally toothed head 60 for engaging a toothed portion 40 in the female coupling member 4 to lock the female coupling member 4 to the associating male coupling member 5, and the other end fixedly mounted with a cap 8. Further, a compression spring 9 is mounted on the polygonal shaft 6 and stopped between the female coupling member 4 and the cap 8 to impart an outward pressure to the cap 8, causing the cap 8 to pull the polygonal shaft 6 in direction toward the inside of the female coupling member 4, and therefore the peripherally toothed head 60 is kept in engagement with the toothed portion 40 of the female coupling member 4. Further, a mounting assembly 10 may be provided at the top side of the holder frame 1 for mounting. As shown in FIGS. 4˜7, the mounting assembly 10 comprises a mounting shaft 13 having a peripherally toothed mounting slot 14, a clamping plate 11 inserted through and movable along the peripherally toothed mounting slot 14 and having an engagement block 12 for engaging the toothed portion of the peripherally toothed mounting slot 14, and a lock screw 15 mounted in the clamping plate 11 for locking the clamping plate 11 to the mounting shaft 13. During application, the mounting frame 3 is affixed to a wall panel, and the object to be supported is mounted on the holder frame 1 or fastened to the mounting assembly 10 at the holder frame 1. When adjusting the tilt angle of the supported object, hold the supported object with one hand and then press the cap 8 against the compression spring 9 with the other hand to disengage the peripherally toothed head 60 from the toothed portion 40 of the female coupling member 4, and then move the supported object to the desired angle. After adjustment, release the hand from the cap 8, and the spring force of the compression spring 9 immediately forces the peripherally toothed head 60 into engagement with the toothed portion 40 of the female coupling member 4 again. Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
|
A
|
A47
|
A47F
|
5
|
10
|
|||
11669071
|
US20080179894A1-20080731
|
HIDDEN FASTENING STRUCTURE
|
ACCEPTED
|
20080716
|
20080731
|
[]
|
E05C500
|
["E05C500"]
|
7427087
|
20070130
|
20080923
|
292
|
095000
|
92207.0
|
ESTREMSKY
|
GARY
|
[{"inventor_name_last": "Chuang", "inventor_name_first": "Cheng-Hsiang", "inventor_city": "Taipei", "inventor_state": "", "inventor_country": "TW"}]
|
A hidden fastening structure applied to an electronic device is provided, which comprises a actuator and a fastener controlled by the actuator, wherein the fastener is rotatably disposed on the electronic device. When the actuator is pushed by external forces in the horizontal direction, the fastener is driven to rotate about the electronic device, thereby providing a hidden position accommodated within the electronic device or a fastening position outside the electronic device.
|
1. A hidden fastening structure, applied to an electronic device, comprising: an actuator movably disposed on the electronic device and having an activation button and a guide piece, wherein the activation button has a fastening part, and the guide piece has a guiding slot and a fastening hole corresponding to the fastening part for being embedded with the fastening part, such that when the activation button is pushed by an external force, the activation button drives the guide piece and the activation button to move to a first position or a second position; and a fastener rotatably disposed on the electronic device having a hidden position accommodated within the electronic device or a fastening position rotatably exposed from the electronic device, wherein a shaft lever extending into the guiding slot is disposed at one side of the fastener, such that when the activation button is located at the first position or the second position, the guide piece drives the fastener to move along the guiding slot, such that the fastener is located at the hidden position or the fastening position. 2. The hidden fastening structure according to claim 1, wherein the electronic device comprises a sliding slot. 3. The hidden fastening structure according to claim 2, wherein the activation button further comprises a key body protruding from the sliding slot. 4. The hidden fastening structure according to claim 1, wherein a first positioning hole and a second positioning hole are further disposed at two opposite ends of the guiding slot, and when the activation button is located at the first position, the shaft lever glides along the guiding slot to be located at the first positioning hole, such that the fastener is located at the hidden position, whereas when the activation button is located at the second position, the shaft lever glides along the guiding slot to be located at the second positioning hole, such that said fastener is located at the fastening position. 5. The hidden fastening structure according to claim 1, wherein the other end of the fastener is pivotally connected to the electronic device. 6. The hidden fastening structure according to claim 1, wherein a plurality of positioning slots are disposed at the activation button, and positioning salient points are separately disposed on the electronic device corresponding to each of the positioning slots, when the activation button is moved to make the fastener rotate to be exposed from the electronic device, each of the positioning salient points is sequentially embedded into each of the positioning slots. 7. The hidden fastening structure according to claim 1, wherein a plurality of positioning slots are disposed on the electronic device, and positioning salient points are separately disposed on the activation button corresponding to each of the positioning slots, when the activation button is moved to make the fastener rotate to be exposed from the electronic device, each of the positioning salient points is sequentially embedded into each of the positioning slots. 8. The hidden fastening structure according to claim 1, wherein an inverted hook is formed at one end of the fastener. 9. (canceled) 10. A hidden fastening structure for an electronic device, comprising: a first body having at least one fastening slot; a second body pivotally connected to the first body; an actuator movably disposed on the second body and having an activation button and a guide piece, wherein the activation button has a fastening part, and the guide piece has a guiding slot and a fastening hole corresponding to the fastening part for being embedded with the fastening part, such that when the activation button is pushed by an external force, the activation button drives the guide piece and the activation button to move to a first position or a second position; and a fastener rotatably disposed on the second body, the fastener having a hidden position accommodated within the second body or a fastening position rotatably exposed from the second body, wherein a shaft lever extending into the guiding slot is disposed at one side of the fastener, such that when the activation button is located at the first position or the second position, the guide piece drives the fastener to move along the guiding slot, such that the fastener is located at the hidden position or the fastening position. 11. The hidden fastening structure for an electronic device according to claim 10, wherein the second body has a sliding slot. 12. The hidden fastening structure for an electronic device according to claim 11, wherein the activation button further comprises a key body protruding from the sliding slot. 13. The hidden fastening structure for an electronic device according to claim 10, wherein a first positioning hole and a second positioning hole are further disposed at two opposite ends of the guiding slot, and when the activation button is located at the first position, the shaft lever glides along the guiding slot to be located at the first positioning hole, such that the fastener is located at the hidden position, whereas when the activation button is located at the second position, the shaft lever glides along the guiding slot to be located at the second positioning hole, such that the fastener is located at the fastening position. 14. The hidden fastening structure for an electronic device according to claim 10, wherein when the second body approaches to the first body, the fastener is located at the fastening position, such that the fastener is fastened at the fastening slot, and when the fastener is located at the hidden position to be released from the fastening slot, the second body pivots relative to the first body. 15. The hidden fastening structure for an electronic device according to claim 10, wherein the other end of the fastener is pivotally connected to the second body. 16. The hidden fastening structure for an electronic device according to claim 10, wherein a plurality of positioning slots is disposed at the activation button, and positioning salient points are separately disposed on the second body corresponding to each of the positioning slots, when the activation button is moved to make the fastener rotate to be exposed from the second body, each of the positioning salient points is sequentially embedded into each of the positioning slots. 17. The hidden fastening structure for an electronic device according to claim 10, wherein a plurality of positioning slots is disposed on the second body, and positioning salient points are separately disposed on the activation button corresponding to each of the positioning slots, when the activation button is moved to make the fastener rotate to be exposed from the second body, each of the positioning salient points is sequentially embedded into each of the positioning slots. 18. The hidden fastening structure for an electronic device according to claim 10, wherein an inverted hook is formed at one end of the fastener, and the fastener is snapped at the fastening slot via the inverted hook. 19. (canceled)
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of Invention The present invention relates to a fastening structure, and more particularly, to a hidden fastening structure suitable for electronic devices that can be covered. 2. Related Art The configuration of a conventional notebook computer is generally divided into two parts: a base and a screen which can be connected to the base via a rotating shaft mechanism. When the notebook is used, the screen is opened from the base. When the screen is closed, a fastener is mounted on the base, so as to fix the screen to the base when the notebook is put away or carried along; otherwise, the screen opens, resulting in scratching of the surface of the screen, dust entering into the gaps of the keyboard, or damage to the rotating shaft mechanism. However, a notebook-like computer has a liquid crystal screen that can be converted from a notebook mode to a tablet mode, i.e., the liquid crystal screen is turned backwards, such that the panel faces outwards and then is drawn close to the keyboard to be closely combined with the keyboard. As such, a liquid crystal display is obtained, i.e., a tablet PC. A locking element is usually disposed at a position where the screen covers the base, so as to prevent the liquid crystal screen from being opened freely. Moreover, the locking element also can be used for locking and positioning when the liquid crystal screen is rotated to be folded into a briefing mode for writing and reading. U.S. Patent Publication US 5,580,107 provides a hidden fastening mechanism, which comprises an extending arm and a winding rope with one end connected to a pivot joint within the screen, and the other end of the winding rope is connected to the extending arm extended from the fastener. Under external forces, the extending arm drives the winding rope, and the winding rope further drives the fastener, such that the fastener is selectively hidden in the screen or exposed from the screen. However, the assembly manner is not practical and the winding rope requires a large space, and thus, it cannot be used in a narrow frame space. U.S. Patent Publication US 6,870,740 provides a-two-way fastening device, wherein both surfaces of the cover overlay and fastened on the base. When external forces are applied to an actuator, the actuator has four statuses of moving positions, such that a fastener is driven to protrude from the base to be fastened or to be released and dropped out from the base, and thus, a restorer drives the fastener and the actuator to return to the initial status. U.S. Patent Publication US 6,965,512 provides a mechanism system with a movable hook, wherein the hook is released from the fixing device when being rotated to be hidden within the lower body, and it is combined with the fixing device when being rotated to be exposed from the lower body, such that the upper body and the lower body are fixedly closed. Moreover, the fastening device includes a handle, a tension spring, and an actuator. The fastening device is used to push the tension spring and further push the handle and the fastener, such that the hook rotates relative to the lower body. However, there are too many parts, and the assembling process is difficult. U.S. Patent Publication US 20050180562 provides a hidden hook driving structure, wherein a connecting lever is driven by pressing a key, and the connecting lever is pivotally connected to a magnetic hook, such that the hook is snapped due to being attracted by the magnetic pieces of the body.
|
<SOH> SUMMARY OF THE INVENTION <EOH>In view of the above disclosed prior arts, a large number of parts are required and the assembling process is difficult, and the assembly method cannot be applied to products in practice. Besides, a large space is demanded, such that it cannot be used in a narrow body. Furthermore, the operating process of the fastener is complicated. Therefore, the present invention provides a hidden fastening structure, wherein the fastening effect in the rotating direction is achieved when being applied with forces in the horizontal direction. The hidden fastening structure disclosed by the present invention is applied to electronic devices, which comprises an actuator and a fastener, wherein the actuator is movably disposed on an electronic device and further comprises an activation button and a guide piece with a guiding slot. Under an external force, the activation button drives the guide piece, such that they together move to a first position and a second position. Further, the fastener is rotatably disposed on the electronic device and has a hidden position accommodated within the electronic device or a fastening position rotatably exposed from the electronic device. Besides, a shaft lever that can be extended into the guiding slot is disposed on one side of the fastener. When the activation button is located at the first or second position, the guide piece drives the fastener to move along the guiding slot, such that the fastener is located at the hidden or fastening position. According to the above object, the present invention further discloses a hidden fastening structure for electronic devices, which comprises a first body, a second body, an actuator, and a fastener. The first body has a fastening slot, while the second body is pivotally connected to the first body. The actuator is movably disposed on the second body and comprises an activation button and a guide piece with a guiding slot. Under an external force, the activation button drives the guide piece and together move to a first position and a second position. Moreover, the fastener is rotatably disposed on the second body and has a hidden position accommodated within the second body or a fastening position rotatably exposed from the second body. Besides, a shaft lever that can be extended into the guiding slot is disposed on one side of the fastener. When the activation button is disposed at the first or second position, the guide piece drives the fastener to move along the guiding slot, such that the fastener is disposed at the hidden or fastening position. The hidden fastening structure disclosed by the present invention not only can reduce the amount of the elements required in the prior art, thereby simplifying the structural configuration, but also convenient and simple to operate, and particularly, it is easy for a user to rotate the fastener by applying forces in the horizontal direction, so as to perform fastening and releasing operations. Moreover, the manufacturing process is simple, and thus the manufacturing cost is reduced. The detailed features and advantages of the present invention are discussed below in detail through the following embodiments. It is easy for any skilled in the art to understand the technical content of the present invention and to implement accordingly. Furthermore, with reference to the content disclosed in the specification, claims, and drawings, the relevant objects and advantages of the present invention are apparent to those skilled in the art. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
|
BACKGROUND OF THE INVENTION 1. Field of Invention The present invention relates to a fastening structure, and more particularly, to a hidden fastening structure suitable for electronic devices that can be covered. 2. Related Art The configuration of a conventional notebook computer is generally divided into two parts: a base and a screen which can be connected to the base via a rotating shaft mechanism. When the notebook is used, the screen is opened from the base. When the screen is closed, a fastener is mounted on the base, so as to fix the screen to the base when the notebook is put away or carried along; otherwise, the screen opens, resulting in scratching of the surface of the screen, dust entering into the gaps of the keyboard, or damage to the rotating shaft mechanism. However, a notebook-like computer has a liquid crystal screen that can be converted from a notebook mode to a tablet mode, i.e., the liquid crystal screen is turned backwards, such that the panel faces outwards and then is drawn close to the keyboard to be closely combined with the keyboard. As such, a liquid crystal display is obtained, i.e., a tablet PC. A locking element is usually disposed at a position where the screen covers the base, so as to prevent the liquid crystal screen from being opened freely. Moreover, the locking element also can be used for locking and positioning when the liquid crystal screen is rotated to be folded into a briefing mode for writing and reading. U.S. Patent Publication US 5,580,107 provides a hidden fastening mechanism, which comprises an extending arm and a winding rope with one end connected to a pivot joint within the screen, and the other end of the winding rope is connected to the extending arm extended from the fastener. Under external forces, the extending arm drives the winding rope, and the winding rope further drives the fastener, such that the fastener is selectively hidden in the screen or exposed from the screen. However, the assembly manner is not practical and the winding rope requires a large space, and thus, it cannot be used in a narrow frame space. U.S. Patent Publication US 6,870,740 provides a-two-way fastening device, wherein both surfaces of the cover overlay and fastened on the base. When external forces are applied to an actuator, the actuator has four statuses of moving positions, such that a fastener is driven to protrude from the base to be fastened or to be released and dropped out from the base, and thus, a restorer drives the fastener and the actuator to return to the initial status. U.S. Patent Publication US 6,965,512 provides a mechanism system with a movable hook, wherein the hook is released from the fixing device when being rotated to be hidden within the lower body, and it is combined with the fixing device when being rotated to be exposed from the lower body, such that the upper body and the lower body are fixedly closed. Moreover, the fastening device includes a handle, a tension spring, and an actuator. The fastening device is used to push the tension spring and further push the handle and the fastener, such that the hook rotates relative to the lower body. However, there are too many parts, and the assembling process is difficult. U.S. Patent Publication US 20050180562 provides a hidden hook driving structure, wherein a connecting lever is driven by pressing a key, and the connecting lever is pivotally connected to a magnetic hook, such that the hook is snapped due to being attracted by the magnetic pieces of the body. SUMMARY OF THE INVENTION In view of the above disclosed prior arts, a large number of parts are required and the assembling process is difficult, and the assembly method cannot be applied to products in practice. Besides, a large space is demanded, such that it cannot be used in a narrow body. Furthermore, the operating process of the fastener is complicated. Therefore, the present invention provides a hidden fastening structure, wherein the fastening effect in the rotating direction is achieved when being applied with forces in the horizontal direction. The hidden fastening structure disclosed by the present invention is applied to electronic devices, which comprises an actuator and a fastener, wherein the actuator is movably disposed on an electronic device and further comprises an activation button and a guide piece with a guiding slot. Under an external force, the activation button drives the guide piece, such that they together move to a first position and a second position. Further, the fastener is rotatably disposed on the electronic device and has a hidden position accommodated within the electronic device or a fastening position rotatably exposed from the electronic device. Besides, a shaft lever that can be extended into the guiding slot is disposed on one side of the fastener. When the activation button is located at the first or second position, the guide piece drives the fastener to move along the guiding slot, such that the fastener is located at the hidden or fastening position. According to the above object, the present invention further discloses a hidden fastening structure for electronic devices, which comprises a first body, a second body, an actuator, and a fastener. The first body has a fastening slot, while the second body is pivotally connected to the first body. The actuator is movably disposed on the second body and comprises an activation button and a guide piece with a guiding slot. Under an external force, the activation button drives the guide piece and together move to a first position and a second position. Moreover, the fastener is rotatably disposed on the second body and has a hidden position accommodated within the second body or a fastening position rotatably exposed from the second body. Besides, a shaft lever that can be extended into the guiding slot is disposed on one side of the fastener. When the activation button is disposed at the first or second position, the guide piece drives the fastener to move along the guiding slot, such that the fastener is disposed at the hidden or fastening position. The hidden fastening structure disclosed by the present invention not only can reduce the amount of the elements required in the prior art, thereby simplifying the structural configuration, but also convenient and simple to operate, and particularly, it is easy for a user to rotate the fastener by applying forces in the horizontal direction, so as to perform fastening and releasing operations. Moreover, the manufacturing process is simple, and thus the manufacturing cost is reduced. The detailed features and advantages of the present invention are discussed below in detail through the following embodiments. It is easy for any skilled in the art to understand the technical content of the present invention and to implement accordingly. Furthermore, with reference to the content disclosed in the specification, claims, and drawings, the relevant objects and advantages of the present invention are apparent to those skilled in the art. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description given herein below for illustration only, which thus is not limitative of the present invention, and wherein: FIG. 1 is an exploded view of a structure of the present invention. FIG. 2 is a schematic view of a structure of a guide piece according to the present invention. FIG. 3 is a schematic view of the appearance of a notebook. FIG. 4A is a schematic view of the using status when the present invention is applied to a notebook. FIG. 4B is another schematic view of the using status when the present invention is applied to a notebook. FIG. 5A is a schematic view of positioning an activation button according to the present invention. FIG. 5B is another schematic view of positioning the activation button according to the present invention. DETAILED DESCRIPTION OF THE INVENTION The hidden fastening structure disclosed by the present invention is applied to an electronic device, which can be, but not limited to, a tablet PC or a notebook, and any device that can be correspondingly closed or opened may utilize the technology disclosed in the present invention. A notebook is taken as an application embodiment in the following detailed description of the present invention. Please refer to FIG. 1 of an exploded view of a hidden fastening structure of the present invention. As shown in FIG. 1, a hidden fastening structure 10 comprises an actuator 11 and a fastener 15. The actuator 11 comprises an activation button 13 and a guide piece 14. The activation button 13 is provided with a key body 131 at one side, and a fastening part 132 at the other side. The guiding slot 141 is disposed at the guide piece 14, and a fastening hole 142 is disposed corresponding to the fastening part 132. A shaft lever 151 is disposed at one side of the fastener 15 which corresponds to the guiding slot 141, and a pivot shaft 152 is disposed at the other side. Besides, an inverted hook 154 is formed at one end of the fastener 15. Please refer to FIG. 2 of a schematic view of a guide piece according to the present invention. As shown in FIG. 2, the activation button 13 in the actuator 11 is embedded into the fastening hole 142 in the guide piece 14 via the fastening part 132. The fastening hole 142 is adjacent to the guiding slot 141. A first positioning hole 1411 and a second positioning hole 1412 are further disposed at two opposite ends of the guiding slot 141. The guiding slot 141 allows the shaft lever 151 of the fastener 15 to be extended. Please refer to FIG. 3, it shows an operation status of a notebook 30. The notebook 30 has a first body 32 and a second body 33. The first body 32 is either a host or a display screen. Likewise, the second body 33 is either a display screen or a host corresponding to the first body 32. In the present invention, the first body 32 is a display screen and the second body 33 is a host. The first body 32 has a bottom wall 322, a top wall 323 corresponding to the bottom wall 322, and a side wall 324 disposed between the bottom wall 322 and the top wall 323. A fastening slot 3221 is formed in the bottom wall 322. The surface of the second body 33 has a panel 332 with a plurality of keys 333 accommodated therein, and a sliding slot 335 is correspondingly disposed on one side of the panel 332. An opening 336 is formed in the panel 332 corresponding to the fastening slot 3221. The activation button 13 protrudes from the sliding slot 335 via the key body 131. Moreover, the second body 33 is pivotally connected to the first body 32, such that the first body 32 and the second body 33 are correspondingly closed and opened. When the first body 32 is intended to cover the second body 33, the bottom wall 322 approaches and substantially contacts the panel 332 of the first body 32. Please refer to FIGS. 1, 2, 3, 4A, and 4B, since the activation button 13 is movably disposed on the second body 33, and the activation button 13 is embedded in the fastening hole 142 via the fastening part 132, when being applied with an external force, the activation button 13 drives the guide piece 14 and together move to a first position P1 or a second position P2. The pivot shaft 152 on the other side of the fastener 15 is disposed on a fixing bracket 331 of the second body 33, such that the other side of the fastener 15 is pivotally connected to the fixing bracket 33-1, and thereby the fastener 15 rotates relative to the second body 33. When the activation button 13 moves along the sliding slot 335 from the first position P1 to the second position P2 under an external force, it simultaneously drives the guide piece 14 to move from the first position PI to the second position P2, and the guide piece 14 further drives the fastener 15 to move along the guiding slot 141. The fastener 15 glides within the guiding slot 141 via the shaft lever 151, i.e., the shaft lever 151 glides from the first positioning hole 1411 to the second positioning hole 1412, as shown in FIG. 2. As such, the fastener 15 rotates relative to the second body 33 to protrude from the opening 336, i.e., moving from a hidden position P3 accommodated within the second body 33 to a fastening position P4 outside the second body 33, as shown in FIGS. 4A and 4B. Likewise, if the activation button 13 is intended to move from the second position P2 to the first position P1, the guide piece 14 drives the fastener 15 to move along the guiding slot 141. The fastener 15 glides within the guiding slot 141 via the shaft lever 151, i.e., the shaft lever 151 glides from the second positioning hole 1412 to the first positioning hole 1411, such that the fastener 15 rotates relative to the second body 33, i.e., moving from the fastening position P4 outside the second body 33 to the hidden position P3 accommodated within the second body 33. When the first body 32 is intended to cover the second body 33, the bottom wall 322 approaches and substantially contacts the panel 332 of the first body 32. At this time, the activation button 13 located at the first position P1 is pushed, such that the shaft lever 151 of the fastener 15 is located at the second positioning hole 1412. The activation button 13 is located at the second position P2, and the fastener 15 is located at the fastening position P4, such that the fastener 15 is fastened to the fastening slot 3221 via the inverted hook 154. When the second body 33 is intended to rotate relative to the first body 32 to make the first body 32 be released from the second body 33, the activation button 13 at the second position P2 is pushed, such that the shaft lever 151 of the fastener 15 is positioned at the first positioning hole 1411. As such, the activation button 13 is located at the first position PI, the fastener 15 is located at the hidden position P3, such that the fastener 15 is removed from the fastening slot 3221 via the inverted hook 154 and then released from the fastening slot 3221. Please refer to FIGS. 5A and 5B. FIG. 5A is a schematic view of positioning an activation button according to the present invention. FIG. 5B is another schematic view of positioning the activation button according to the present invention. As shown in FIG. SA, the activation button 13 is further provided with a plurality of positioning slots 133A, and a positioning salient point 338A is disposed on the second body 33 corresponding to each of the positioning slots 133A. When the activation button 13 is pushed to perform the fastening operation, each of the positioning salient points 338A is sequentially embedded in each of the positioning slots 133A. As shown in FIG. 5B, the activation button 13 is further provided with a plurality of positioning salient points 133B, and positioning slots 338B are disposed on the second body 33 corresponding to each of the positioning salient points 133B. When the activation button 13 is pushed to perform the fastening operation, each of the positioning salient points 133B is sequentially embedded in each of the positioning slots 338B. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
|
E
|
E05
|
E05C
|
5
|
00
|
|||
11713217
|
US20070211604A1-20070913
|
Optical pickup apparatus
|
ACCEPTED
|
20070829
|
20070913
|
[]
|
G11B700
|
["G11B700"]
|
7710847
|
20070302
|
20100504
|
369
|
112080
|
70527.0
|
HUBER
|
PAUL
|
[{"inventor_name_last": "Ikenaka", "inventor_name_first": "Kiyono", "inventor_city": "Tokyo", "inventor_state": "", "inventor_country": "JP"}]
|
An optical pickup apparatus for recording and/or reproducing information for an optical information recording medium, comprising a light converging optical system including a coupling lens and an objective lens, wherein a first diffraction structure is installed on the objective lens, and a second diffraction structure is arranged on the coupling lens, whereby the spherical aberration and chromatic aberration caused by the difference in the thickness of the protective layer are corrected in the light converging optical system as a whole.
|
1. An optical pickup apparatus comprising: a first light source for emitting a first light flux having a wavelength λ1 (nm); a second light source for emitting a second light flux having a wavelength λ2 (nm) (λ2>λ1); and a light converging optical system including a coupling lens and an objective lens, wherein the light converging system converges a light flux from the first light source onto an information recording surface of a first optical information recording medium through a protective layer having a thickness t1 so that recording and/or reproducing information is conducted for the first optical information recording medium, and converges a light flux from the second light source onto an information recording surface of a second optical information recording medium through a protective layer having a thickness t2 (t1≦t2) so that recording and/or reproducing information is conducted for the second optical information recording medium, wherein the first light source and the second light source are arranged so that a distance between the first light source and the coupling lens become optically equal to a distance between the second light source and the coupling lens, wherein a first diffraction structure is provided on an optical surface of the objective lens through which both the light flux of the wavelength λ1 and that of the wavelength λ2 pass, wherein the following equation (1) is satisfied when d1 denotes an average depth of step structures in the optical axial direction of the first diffraction structure, wherein the following equation (2) is satisfied by the chromatic aberration ΔfB of the composite system including the objective lens and coupling lens with respect to the light flux of the wavelength λ1, wherein a second diffraction structure is formed on an optical surface of the coupling lens through which both the light flux of the wavelength λ1 and that of the wavelength λ2 pass, and wherein the following equation (3) is satisfied when d2 denotes the average depth of step structures in the optical axial direction of the second diffraction structure: λ1×2/(n1−1)×1.0≦d1 (nm)≦λ1×2/(n1−1)×1.3 (1) −0.4≦ΔfB(μm/nm)+1.29×10−4×f1×(m2−m1)≦0.1 (2) λ1×2/(n2−1)×1.0≦d2(nm)≦λ1×2/(n2−1)×1.3 (3) where m1 denotes the magnification of the objective lens at the time of recording or reproduction of information using the first optical information recording medium; f1 indicates the focal distance of the objective lens at the time of recording or reproduction of information using the first optical information recording medium; m2 shows the magnification of the objective lens at the time of recording or reproduction of information using the second optical information recording medium; n1 represents the refractive index of the material constituting the first diffraction structure with respect to the light of wavelength λ1; and n2 represents the refractive index of the material constituting the second diffraction structure with respect to the light of wavelength λ1. 2. The optical pickup apparatus of claim 1, wherein the following formula is satisfied: −0.02<m2−m1≧0 (4). 3. The optical pickup apparatus of claim 1, wherein the light flux reflected from the information recording surface of the first optical information recording medium and the light flux reflected from the information recording surface of the second optical information recording medium enter the light receiving surface of a common optical detector. 4. The optical pickup apparatus of claim 2, wherein the light flux reflected from the information recording surface of the first optical information recording medium and the light flux reflected from the information recording surface of the second optical information recording medium enter the light receiving surface of a common optical detector. 5. The optical pickup apparatus of claim 1, wherein the following equation is satisfied: −1/6≦mG≦−1/10 (5) wherein mG denotes a magnification of a composite system made up of the objective lens and the coupling lens at the time of information recording or reproduction using the first optical information recording medium. 6. The optical pickup apparatus of claim 2, wherein the following equation is satisfied: −1/6≦mG≧−1/10 (5) wherein mG denotes a magnification of a composite system made up of the objective lens and the coupling lens at the time of information recording or reproduction using the first optical information recording medium. 7. The optical pickup apparatus of claim 3, wherein the following equation is satisfied: −1/6≦mG≦−1/10 (5) wherein mG denotes a magnification of a composite system made up of the objective lens and the coupling lens at the time of information recording or reproduction using the first optical information recording medium. 8. The optical pickup apparatus of claim 1, wherein the first light source and the second light source are accommodated in a common package. 9. The optical pickup apparatus of claim 2, wherein the first light source and the second light source are accommodated in a common package. 10. The optical pickup apparatus of claim 3, wherein the first light source and the second light source are accommodated in a common package. 11. The optical pickup apparatus of claim 5, wherein the first light source and the second light source are accommodated in a common package. 12. The optical pickup apparatus of claim 1, further comprising a third light source for emitting a third light flux having a wavelength λ3 (nm) (λ2<λ3) is provided, wherein the light converging optical system converges a light flux from the third light source onto an information recording surface of a third optical information recording medium through a protective layer having a thickness t3 (t2<t3), whereby information recording and/or reproduction is enabled. 13. The optical pickup apparatus of claim 2, further comprising a third light source for emitting a third light flux having a wavelength λ3 (nm) (λ2<λ3) is provided, wherein the light converging optical system converges a light flux from the third light source onto an information recording surface of a third optical information recording medium through a protective layer having a thickness t3 (t2<t3), whereby information recording and/or reproduction is enabled. 14. The optical pickup apparatus of claim 3, further comprising a third light source for emitting a third light flux having a wavelength λ3 (nm) (λ2<λ3) is provided, wherein the light converging optical system converges a light flux from the third light source onto an information recording surface of a third optical information recording medium through a protective layer having a thickness t3 (t2<t3), whereby information recording and/or reproduction is enabled. 15. The optical pickup apparatus of claim 5, further comprising a third light source for emitting a third light flux having a wavelength λ3 (nm) (λ2<λ3) is provided, wherein the light converging optical system converges a light flux from the third light source onto an information recording surface of a third optical information recording medium through a protective layer having a thickness t3 (t2<t3), whereby information recording and/or reproduction is enabled. 16. The optical pickup apparatus of claim 8, further comprising a third light source for emitting a third light flux having a wavelength λ3 (nm) (λ2<λ3) is provided, wherein the light converging optical system converges a light flux from the third light source onto an information recording surface of a third optical information recording medium through a protective layer having a thickness t3 (t2<t3), whereby information recording and/or reproduction is enabled. 17. The optical pickup apparatus of claim 1, wherein the wavelength λ1 and the wavelength λ2 satisfy following equation: 1.5<λ1/λ2<1.7
|
<SOH> BACKGROUND OF THE INVENTION <EOH>In recent years, there has been a rapid progress in the research and development of a high-density optical disk system capable of recording and/or reproduction (hereinafter referred to as “recording/reproduction) of information, using a blue-violet semiconductor laser having a wavelength of about 405 nm. For example, an optical disk for conducting information recording/reproduction based on NA of 0.85 and light source wavelength of 405 nm—a so-called Blu-ray Disc (hereinafter referred to as “BD”)—is capable of recording 23 through 27 GB information per layer, as compared to the optical disk having a diameter of 12 cm, the same diameter as that of the DVD (NA: 0.6; light source wavelength: 650 nm, memory size: 4.7 GB). Further, an optical disk to conduct information recording/reproduction based on NA of 0.65 and light source wavelength of 405 nm—so-called HD DVD (hereinafter referred to as “HD”)—is capable of recording 15 through 20 GB information per layer as compared to the optical disk having a diameter of 12 cm. When the BD is used, there is an increase in the coma aberration caused by the skew of the optical disk. In the present Specification, such an optical disk will be referred to as a “high-density optical disk”. The value of the optical disk player/recorder as a commercial product such as optical disk player or recorder (hereinafter referred to as “optical disk player/recorder) cannot be said to be sufficient in some cases if information recording/reproduction can be conducted only when a high-density optical disk is used. At present, since the DVD and CD (compact disks) for recording a great variety of information are put on the market, the commercial value of the optical disk player/recorder for high density optical disk is enhanced if adequate information recording/reproduction capacity is ensured for the DVD and CD owned by the user, for example. Thus, the optical pickup apparatus mounted on the optical disk player/recorder for high-density optical disk is desired to ensure adequate information recording/reproduction for any of the high-density optical disk, DVD and CD. A method has been proposed to permit adequate information recording and/or reproduction while maintaining compatibility with any of the high-density optical disk, DVD and CD. According to this method, selective switching is carried out between the optical system for high-density optical disk and the optical system for DVD and CD in response to the recording density of the optical disk for information recording and/or reproduction. However, this method requires a plurality of optical systems, and is disadvantageous from the viewpoint of downsizing and cost cutting. To simplify the structure of the optical pickup apparatus and to reduce the cost, it is preferred in the optical pickup apparatus characterized by compatibility that standardization should be achieved between the optical system for high-density optical disk and the optical system for the DVD and CD wherever possible, thereby minimizing the number of the optical parts constituting the optical pickup apparatus. Further, standardization of the objective optical system laid opposite to the optical disk is the shortest way to simplify the structure of the optical pickup apparatus and to reduce the cost. The Patent Document 1 discloses an optical pickup apparatus wherein a diffraction structure is employed to maintain compatibility between a DVD and CD in information recording and/or reproduction. [Patent Document 1] Unexamined Japanese Patent Application Publication No. 2005-141800 However, the optical pickup apparatus of the Patent Document 1 fails to provide adequate compatibility between the high-density optical disk and DVD in information recording and/or reproduction. The thicknesses of protective layer and the wavelength in the optical disks intended for compatible use are different between the high-density optical disk and DVD, and between the DVD and CD. This makes it difficult to ensure compatibility in use and correction of chromatic aberration cannot be ensured. The following specifically describes the compatibility in use: The objective lens and collimator in the Patent Document 1 is provided with a diffraction structure for emitting the diffracted light highly efficient for the light of the DVD and CD waveforms. When the light of a high-density optical disk has entered, highly efficient diffracted light is emitted. However, since the diffracted light enters the objective lens at the angle of divergence almost the same as that of the CD wavelength light, the objective lens excessively corrects the spherical aberration generated by the thickness of the protective layer of the high-density optical disk. This arrangement fails to achieve the compatibility in use. Further, the following problem is found in the correction of chromatic aberration. In the refractive objective lens, the light of the high-density optical disk wavelength has a chromatic aberration 2.5 through 3.5 times greater than that of the CD wavelength. Thus, in the optical system optimized to the light of CD wavelength, chromatic aberration remains uncorrected.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The object of the present invention is to solve the problems of the conventional art and to provide an optical pickup apparatus capable of information recording and/or reproduction compatibly using different types of optical information recording media with compatibility maintained among these media. According to the first aspect of the present invention, there is provided an optical pickup apparatus comprising: a first light source for emitting a first light flux having a wavelength λ 1 (nm); a second light source for emitting a second light flux having a wavelength λ 2 (nm) (λ 2 >λ 1 ); and a light converging optical system including a coupling lens and an objective lens, wherein the light converging system converges a light flux from the first light source onto an information recording surface of a first optical information recording medium through a protective layer having a thickness t 1 so that recording and/or reproducing information is conducted for the first optical information recording medium, and converges a light flux from the second light source onto an information recording surface of a second optical information recording medium through a protective layer having a thickness t 2 (t 1 ≦t 2 ) so that recording and/or reproducing information is conducted for the second optical information recording medium, wherein the first light source and the second light source are arranged so that a distance between the first light source and the coupling lens become optically equal to a distance between the second light source and the coupling lens, wherein a first diffraction structure is provided on an optical surface of the objective lens through which both the light flux of the wavelength λ 1 and that of the wavelength λ 2 pass, wherein the following equation (1) is satisfied when d 1 denotes an average depth of step structures in the optical axial direction of the first diffraction structure, wherein the following equation (2) is satisfied by the chromatic aberration ΔfB of the composite system including the objective lens and coupling lens with respect to the light flux of the wavelength λ 1 , wherein a second diffraction structure is formed on an optical surface of the coupling lens through which both the light flux of the wavelength λ 1 and that of the wavelength λ 2 pass, and wherein the following equation (3) is satisfied when d 2 denotes the average depth of step structures in the optical axial direction of the second diffraction structure: in-line-formulae description="In-line Formulae" end="lead"? λ1×2/( n 1−1)×1.0 ≦d 1 (nm)≦λ1×2/( n 1−1)×1.3 (1) in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? −0.4 ≦ΔfB (μm/nm)+ 1.29×10 −4 ×f 1×( m 2− m 1)≦0.1 (2) in-line-formulae description="In-line Formulae" end="tail"? in-line-formulae description="In-line Formulae" end="lead"? λ1×2/( n 2−1)×1.0 ≦d 2(nm)≦λ1×2/( n 2−1)×1.3 (3) in-line-formulae description="In-line Formulae" end="tail"? where m 1 denotes the magnification of the objective lens at the time of recording or reproduction of information using the first optical information recording medium; f 1 indicates the focal distance of the objective lens at the time of recording or reproduction of information using the first optical information recording medium; m 2 shows the magnification of the objective lens at the time of recording or reproduction of information using the second optical information recording medium; n 1 represents the refractive index of the material constituting the first diffraction structure with respect to the light of wavelength λ 1 ; and n 2 represents the refractive index of the material constituting the second diffraction structure with respect to the light of wavelength λ 1 . The present invention uses a diffraction structure to ensure compatibility between the first optical information recording medium and the second optical information recording medium. In this case, the problem is where to install the diffraction structure. The NA of the objective lens is generally greater than that of the coupling lens. Accordingly, if the diffraction structure for correcting the spherical aberration and the chromatic aberration resulting from the difference in the thickness of the protective layer is installed on the optical surface of the objective lens, there is concern about the forming property of the diffraction structure because there is a large visual angle of the lens surface on the end of effective diameter having the smallest pitch. By contrast, the coupling lens has a smaller NA. Thus, the problem is that only the chromatic aberration can be corrected, even if a diffraction structure is arranged on the optical surface thereof. In the present invention, a first diffraction structure is installed on the objective lens, and a second diffraction structure is arranged on the coupling lens, whereby the spherical aberration and chromatic aberration caused by the difference in the thickness of the protective layer are corrected in the light converging optical system as a whole. To put it more specifically, the first light source and second light source are placed at positions optically equal distance from the objective lens. Then the optical magnification m 1 of the objective lens on the light flux of wavelength λ 1 and optical magnification m 2 of the objective lens on the light flux of wavelength λ 2 are determined so as to achieve compatibility. Then, based on this determination, the specifications of the second diffraction structure of the coupling lens can be determined. The chromatic aberration of the entire optical system is determined by the concept of the optical pickup apparatus such as usage of recording or reproduction alone. Further, if the specifications on the design value of the second diffraction structure are determined, the specifications of the first diffraction structure of the objective lens can be determined in such a way so as to satisfy the equation (2). As described above, if the chromatic aberration of the objective lens is corrected, the chromatic aberration of that composite system is corrected, even if the chromatic aberration remains on the coupling lens. The spherical aberration and chromatic aberration caused by the difference in the thickness of the protective layer can be adequately corrected in the light converging optical system as a whole. It has been found out that the chromatic aberration of the objective lens is inversely proportional to the chromatic aberration of the coupling lens. The amount of chromatic aberration refers to the amount of displacement of the best defocus when there is a change of 1 nm in the wavelength of the light source. Further, if the first diffraction structure and second diffraction structure are designed so as to satisfy the equations (1) and (3), the intensity of the secondary diffracted light is maximized in the light flux of the wavelength λ 1 and the intensity of the primary diffracted light is maximized in the light flux of the wavelength λ 2 , regardless of which of the diffraction structures has been passed through by light. Thus, the utilization efficiency of light can be enhanced by using the diffracted light of lower order. The average step depth d 1 is defined as the average value of the step depths of diffraction structures formed in the area through which both the wavelengths λ 1 and λ 2 pass, in the objective lens. Namely, it corresponds to the value obtained by dividing the total of the depth of the step formed in this area, by the number of steps. When a third light source of the wavelength λ 3 is provided, the average step depth d 1 is defined as the average value of the step depths diffraction structures formed in the area through which all of the wavelengths λ 1 , λ 2 and λ 3 pass, in the objective lens. The average step depth d 2 is defined as the average value of the step depths of diffraction structures formed in the area through which both the wavelengths λ 1 and λ 2 pass, in the coupling lens. Namely, it corresponds to the value obtained by dividing the total of the depth of the step formed in this area, by the number of steps. Even when the third light source of the wavelength λ 3 is provided, the average step depth d 2 is defined as the average value of the step depths of diffraction structures formed in the area through which both the wavelengths λ 1 and λ 2 pass, in the objective lens. Namely, it corresponds to the value obtained by dividing the total of the depth of the step formed in this area, by the number of steps. According to the second aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, that satisfies the following equation, and therefore, both the first and second diffraction structures is designed in a structure with a smaller number of strap, whereby the loss of light passing through the diffraction structure is reduced. in-line-formulae description="In-line Formulae" end="lead"? −0.02 <m 2 −m 1<0 (4) in-line-formulae description="In-line Formulae" end="tail"? According to the third aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, wherein the light flux reflected from the information recording surface of the first optical information recording medium and the light flux reflected from the information recording surface of the second optical information recording medium enter the light receiving surface of a common optical detector. Therefore, compact configuration of the optical pickup apparatus is achieved by use of the common optical detector. According to the fourth aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, wherein the following equation is satisfied, and therefore, the effect of correcting the chromatic aberration can be enhanced when the first optical information recording medium is used. in-line-formulae description="In-line Formulae" end="lead"? −1/6≦mG≦−1/10 (5) in-line-formulae description="In-line Formulae" end="tail"? wherein mG denotes the magnification of the composite system made up of the objective lens and coupling lens at the time of information recording or reproduction using the first optical information recording medium. According to the fifth aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, wherein the first and second light sources are accommodated in a common package, thereby permitting further downsizing of the optical pickup apparatus. According to the sixth aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, wherein a third light source of wavelength λ 3 (λ 2 <λ 3 ) is further provided, and the light converging optical system converges a light flux from the third light source onto an information recording surface of a third optical information recording medium through a protective layer having a thickness t 3 (t 2 <t 3 ), whereby information recording and/or reproduction is enabled. In the present specification, if there are a lens capable of light convergence arranged opposite the optical information recording medium at the position closest to this recording medium mounted on the optical pickup apparatus; and an optical element or lens which is mounted on an actuator for driving the lens and is driven integrally with the lens for light convergence, then the objective lens is defined as the optical element group including the optical element or lens. In other words, the objective lens can be made up of a plurality of lenses although it is preferably made up of a single lens. The present invention provides an optical pickup apparatus capable of information recording and/or reproduction using different types of optical information recording media with compatibility maintained among these media. BRFSUM description="Brief Summary" end="tail"?
|
This application is based on Japanese Patent Application No. 2006-691082 filed on Mar. 7, 2006, in Japanese Patent Office, the entire content of which is hereby incorporated by reference. FIELD OF THE INVENTION The present invention relates to an optical pickup apparatus, particularly an optical pickup apparatus capable of information recording and/or reproduction using different types of optical information recording media with compatibility maintained among these media. BACKGROUND OF THE INVENTION In recent years, there has been a rapid progress in the research and development of a high-density optical disk system capable of recording and/or reproduction (hereinafter referred to as “recording/reproduction) of information, using a blue-violet semiconductor laser having a wavelength of about 405 nm. For example, an optical disk for conducting information recording/reproduction based on NA of 0.85 and light source wavelength of 405 nm—a so-called Blu-ray Disc (hereinafter referred to as “BD”)—is capable of recording 23 through 27 GB information per layer, as compared to the optical disk having a diameter of 12 cm, the same diameter as that of the DVD (NA: 0.6; light source wavelength: 650 nm, memory size: 4.7 GB). Further, an optical disk to conduct information recording/reproduction based on NA of 0.65 and light source wavelength of 405 nm—so-called HD DVD (hereinafter referred to as “HD”)—is capable of recording 15 through 20 GB information per layer as compared to the optical disk having a diameter of 12 cm. When the BD is used, there is an increase in the coma aberration caused by the skew of the optical disk. In the present Specification, such an optical disk will be referred to as a “high-density optical disk”. The value of the optical disk player/recorder as a commercial product such as optical disk player or recorder (hereinafter referred to as “optical disk player/recorder) cannot be said to be sufficient in some cases if information recording/reproduction can be conducted only when a high-density optical disk is used. At present, since the DVD and CD (compact disks) for recording a great variety of information are put on the market, the commercial value of the optical disk player/recorder for high density optical disk is enhanced if adequate information recording/reproduction capacity is ensured for the DVD and CD owned by the user, for example. Thus, the optical pickup apparatus mounted on the optical disk player/recorder for high-density optical disk is desired to ensure adequate information recording/reproduction for any of the high-density optical disk, DVD and CD. A method has been proposed to permit adequate information recording and/or reproduction while maintaining compatibility with any of the high-density optical disk, DVD and CD. According to this method, selective switching is carried out between the optical system for high-density optical disk and the optical system for DVD and CD in response to the recording density of the optical disk for information recording and/or reproduction. However, this method requires a plurality of optical systems, and is disadvantageous from the viewpoint of downsizing and cost cutting. To simplify the structure of the optical pickup apparatus and to reduce the cost, it is preferred in the optical pickup apparatus characterized by compatibility that standardization should be achieved between the optical system for high-density optical disk and the optical system for the DVD and CD wherever possible, thereby minimizing the number of the optical parts constituting the optical pickup apparatus. Further, standardization of the objective optical system laid opposite to the optical disk is the shortest way to simplify the structure of the optical pickup apparatus and to reduce the cost. The Patent Document 1 discloses an optical pickup apparatus wherein a diffraction structure is employed to maintain compatibility between a DVD and CD in information recording and/or reproduction. [Patent Document 1] Unexamined Japanese Patent Application Publication No. 2005-141800 However, the optical pickup apparatus of the Patent Document 1 fails to provide adequate compatibility between the high-density optical disk and DVD in information recording and/or reproduction. The thicknesses of protective layer and the wavelength in the optical disks intended for compatible use are different between the high-density optical disk and DVD, and between the DVD and CD. This makes it difficult to ensure compatibility in use and correction of chromatic aberration cannot be ensured. The following specifically describes the compatibility in use: The objective lens and collimator in the Patent Document 1 is provided with a diffraction structure for emitting the diffracted light highly efficient for the light of the DVD and CD waveforms. When the light of a high-density optical disk has entered, highly efficient diffracted light is emitted. However, since the diffracted light enters the objective lens at the angle of divergence almost the same as that of the CD wavelength light, the objective lens excessively corrects the spherical aberration generated by the thickness of the protective layer of the high-density optical disk. This arrangement fails to achieve the compatibility in use. Further, the following problem is found in the correction of chromatic aberration. In the refractive objective lens, the light of the high-density optical disk wavelength has a chromatic aberration 2.5 through 3.5 times greater than that of the CD wavelength. Thus, in the optical system optimized to the light of CD wavelength, chromatic aberration remains uncorrected. SUMMARY OF THE INVENTION The object of the present invention is to solve the problems of the conventional art and to provide an optical pickup apparatus capable of information recording and/or reproduction compatibly using different types of optical information recording media with compatibility maintained among these media. According to the first aspect of the present invention, there is provided an optical pickup apparatus comprising: a first light source for emitting a first light flux having a wavelength λ1 (nm); a second light source for emitting a second light flux having a wavelength λ2 (nm) (λ2>λ1); and a light converging optical system including a coupling lens and an objective lens, wherein the light converging system converges a light flux from the first light source onto an information recording surface of a first optical information recording medium through a protective layer having a thickness t1 so that recording and/or reproducing information is conducted for the first optical information recording medium, and converges a light flux from the second light source onto an information recording surface of a second optical information recording medium through a protective layer having a thickness t2 (t1≦t2) so that recording and/or reproducing information is conducted for the second optical information recording medium, wherein the first light source and the second light source are arranged so that a distance between the first light source and the coupling lens become optically equal to a distance between the second light source and the coupling lens, wherein a first diffraction structure is provided on an optical surface of the objective lens through which both the light flux of the wavelength λ1 and that of the wavelength λ2 pass, wherein the following equation (1) is satisfied when d1 denotes an average depth of step structures in the optical axial direction of the first diffraction structure, wherein the following equation (2) is satisfied by the chromatic aberration ΔfB of the composite system including the objective lens and coupling lens with respect to the light flux of the wavelength λ1, wherein a second diffraction structure is formed on an optical surface of the coupling lens through which both the light flux of the wavelength λ1 and that of the wavelength λ2 pass, and wherein the following equation (3) is satisfied when d2 denotes the average depth of step structures in the optical axial direction of the second diffraction structure: λ1×2/(n1−1)×1.0≦d1 (nm)≦λ1×2/(n1−1)×1.3 (1) −0.4≦ΔfB (μm/nm)+1.29×10−4×f1×(m2−m1)≦0.1 (2) λ1×2/(n2−1)×1.0≦d2(nm)≦λ1×2/(n2−1)×1.3 (3) where m1 denotes the magnification of the objective lens at the time of recording or reproduction of information using the first optical information recording medium; f1 indicates the focal distance of the objective lens at the time of recording or reproduction of information using the first optical information recording medium; m2 shows the magnification of the objective lens at the time of recording or reproduction of information using the second optical information recording medium; n1 represents the refractive index of the material constituting the first diffraction structure with respect to the light of wavelength λ1; and n2 represents the refractive index of the material constituting the second diffraction structure with respect to the light of wavelength λ1. The present invention uses a diffraction structure to ensure compatibility between the first optical information recording medium and the second optical information recording medium. In this case, the problem is where to install the diffraction structure. The NA of the objective lens is generally greater than that of the coupling lens. Accordingly, if the diffraction structure for correcting the spherical aberration and the chromatic aberration resulting from the difference in the thickness of the protective layer is installed on the optical surface of the objective lens, there is concern about the forming property of the diffraction structure because there is a large visual angle of the lens surface on the end of effective diameter having the smallest pitch. By contrast, the coupling lens has a smaller NA. Thus, the problem is that only the chromatic aberration can be corrected, even if a diffraction structure is arranged on the optical surface thereof. In the present invention, a first diffraction structure is installed on the objective lens, and a second diffraction structure is arranged on the coupling lens, whereby the spherical aberration and chromatic aberration caused by the difference in the thickness of the protective layer are corrected in the light converging optical system as a whole. To put it more specifically, the first light source and second light source are placed at positions optically equal distance from the objective lens. Then the optical magnification m1 of the objective lens on the light flux of wavelength λ1 and optical magnification m2 of the objective lens on the light flux of wavelength λ2 are determined so as to achieve compatibility. Then, based on this determination, the specifications of the second diffraction structure of the coupling lens can be determined. The chromatic aberration of the entire optical system is determined by the concept of the optical pickup apparatus such as usage of recording or reproduction alone. Further, if the specifications on the design value of the second diffraction structure are determined, the specifications of the first diffraction structure of the objective lens can be determined in such a way so as to satisfy the equation (2). As described above, if the chromatic aberration of the objective lens is corrected, the chromatic aberration of that composite system is corrected, even if the chromatic aberration remains on the coupling lens. The spherical aberration and chromatic aberration caused by the difference in the thickness of the protective layer can be adequately corrected in the light converging optical system as a whole. It has been found out that the chromatic aberration of the objective lens is inversely proportional to the chromatic aberration of the coupling lens. The amount of chromatic aberration refers to the amount of displacement of the best defocus when there is a change of 1 nm in the wavelength of the light source. Further, if the first diffraction structure and second diffraction structure are designed so as to satisfy the equations (1) and (3), the intensity of the secondary diffracted light is maximized in the light flux of the wavelength λ1 and the intensity of the primary diffracted light is maximized in the light flux of the wavelength λ2, regardless of which of the diffraction structures has been passed through by light. Thus, the utilization efficiency of light can be enhanced by using the diffracted light of lower order. The average step depth d1 is defined as the average value of the step depths of diffraction structures formed in the area through which both the wavelengths λ1 and λ2 pass, in the objective lens. Namely, it corresponds to the value obtained by dividing the total of the depth of the step formed in this area, by the number of steps. When a third light source of the wavelength λ3 is provided, the average step depth d1 is defined as the average value of the step depths diffraction structures formed in the area through which all of the wavelengths λ1, λ2 and λ3 pass, in the objective lens. The average step depth d2 is defined as the average value of the step depths of diffraction structures formed in the area through which both the wavelengths λ1 and λ2 pass, in the coupling lens. Namely, it corresponds to the value obtained by dividing the total of the depth of the step formed in this area, by the number of steps. Even when the third light source of the wavelength λ3 is provided, the average step depth d2 is defined as the average value of the step depths of diffraction structures formed in the area through which both the wavelengths λ1 and λ2 pass, in the objective lens. Namely, it corresponds to the value obtained by dividing the total of the depth of the step formed in this area, by the number of steps. According to the second aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, that satisfies the following equation, and therefore, both the first and second diffraction structures is designed in a structure with a smaller number of strap, whereby the loss of light passing through the diffraction structure is reduced. −0.02<m2−m1<0 (4) According to the third aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, wherein the light flux reflected from the information recording surface of the first optical information recording medium and the light flux reflected from the information recording surface of the second optical information recording medium enter the light receiving surface of a common optical detector. Therefore, compact configuration of the optical pickup apparatus is achieved by use of the common optical detector. According to the fourth aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, wherein the following equation is satisfied, and therefore, the effect of correcting the chromatic aberration can be enhanced when the first optical information recording medium is used. −1/6≦mG≦−1/10 (5) wherein mG denotes the magnification of the composite system made up of the objective lens and coupling lens at the time of information recording or reproduction using the first optical information recording medium. According to the fifth aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, wherein the first and second light sources are accommodated in a common package, thereby permitting further downsizing of the optical pickup apparatus. According to the sixth aspect of the present invention, there is provided the optical pickup apparatus of the first aspect of the present invention, wherein a third light source of wavelength λ3 (λ2<λ3) is further provided, and the light converging optical system converges a light flux from the third light source onto an information recording surface of a third optical information recording medium through a protective layer having a thickness t3 (t2<t3), whereby information recording and/or reproduction is enabled. In the present specification, if there are a lens capable of light convergence arranged opposite the optical information recording medium at the position closest to this recording medium mounted on the optical pickup apparatus; and an optical element or lens which is mounted on an actuator for driving the lens and is driven integrally with the lens for light convergence, then the objective lens is defined as the optical element group including the optical element or lens. In other words, the objective lens can be made up of a plurality of lenses although it is preferably made up of a single lens. The present invention provides an optical pickup apparatus capable of information recording and/or reproduction using different types of optical information recording media with compatibility maintained among these media. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a drawing schematically representing the structure of an optical pickup apparatus PU1 of the present embodiment capable of correct information recording/reproduction using an HD, DVD and CD as different types of optical information recording media (also called the optical disks). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes the embodiment of the present invention with reference to drawings: FIG. 1 is a drawing schematically representing the structure of an optical pickup apparatus PU1 of the present embodiment capable of correct information recording/reproduction using an HD, DVD and CD as different types of optical information recording media (also called the optical disks). This optical pickup apparatus PU1 can be mounted on an optical information recording/reproduction apparatus. The optical pickup apparatus PU1 includes: a 2-laser 1-package 2L1P wherein a common package located equidistant from the objective lens accommodates: a first semiconductor laser for emitting the blue-violet laser light flux (the first light flux) of λ1=407 nm, wherein light is emitted at the time of information recording/reproduction using the HD as a high-density optical disk; and a second semiconductor laser for emitting the red laser light flux (the second light flux) of λ2=655 nm, wherein light is emitted at the time of information recording/reproduction using the DVD; a CD hologram laser LD3 integrally containing a third semiconductor laser (third light source) for emitting infrared laser light flux (third light flux) of λ3=785 nm, wherein light is emitted at the time of information recording/reproduction using the CD; and a CD optical detector; an optical detector PD shared by an HD and DVD; a coupling lens (also called the outgoing angle conversion element, the same hereafter) CUL, wherein a diffraction structure is formed; an objective lens OBJ capable of converging the incoming laser light flux on the information recording surface of the optical disk; a polarized beam splitter (also called the separation unit, the same hereafter) PBS; a dichroic prism DP (or a half-mirror); a λ/4 wave plate QWP; and a sensor lens SN for providing astigmatism to the light flux reflected by the optical disk. The optical surfaces of the coupling lens CUL and objective lens OBJ are provided with the diffraction structures, wherein the amount of the secondary diffracted light is maximized when the light flux of wavelength λ1 has passed by, and the amount of the primary diffracted light is maximized when the light flux of wavelengths λ2 and λ3 has passed by. In addition to the semiconductor laser LD1, a blue-violet SHG laser can be used as a light source for HD. In the optical pickup apparatus PU1, light is emitted from the first semiconductor laser (also called the first light source, the same hereinafter) of the 2-laser 1-package 2L1P at the time of information recording/reproduction using the HD. The divergent light flux emitted from the first semiconductor laser passes through the polarized beam splitter PBS and dichroic prism DP, and is converted into the finite convergent light flux of convergent angle θ1 by the coupling lens CUL. Then this light passes through the λ/4 wave plate QWP. After the diameter of the light flux has been controlled by an aperture (not illustrated), the objective lens OBJ causes the light to form a spot on the information recording surface through the HD protective layer. The objective lens OBJ conducts focusing and tracking through the biaxial actuator (not illustrated) arranged on the periphery. The reflected light flux having been modulated by the information pit on the information recording surface of the HD again passes through the objective lens OBJ and λ/4 wave plate QWP. After passing through the coupling lens CUL and dichroic prism DP, the light is reflected by the polarized beam splitter PBS and is provided with astigmatism by the sensor lens SN. Then the light is converged on the light receiving surface of the optical detector PD. Then the information recorded on the HD can be read using the output signal of the optical detector PD. In the optical pickup apparatus PU1, at the time of information recording/reproduction using the DVD, light is emitted from the second semiconductor laser (also called the second light source, the same hereafter) of the 2-laser 1-package 2L1P. The divergent light flux emitted from the second semiconductor laser passes through the polarized beam splitter PBS and dichroic prism DP, and is converted into the finite converged light flux or infinite light flux or finite divergent light flux of convergent angle θ2 (θ1 ≠θ2) by the coupling lens CUL. The light flux then passes through the λ/4 wave plate QWP. After the diameter of the light flux has been controlled by an aperture (not illustrated), the objective lens OBJ causes the light to form a spot on the information recording surface through the protective layer of the DVD. The objective lens OBJ conducts focusing and tracking through the biaxial actuator (not illustrated) arranged on the periphery. The reflected light flux having been modulated by the information pit on the information recording surface of the DVD again passes through the objective lens OBJ and λ/4 wave plate QWP. After passing through the coupling lens CUL and dichroic prism DP, the light is reflected by the polarized beam splitter PBS and is provided with astigmatism by the sensor lens SN. Then the light is converged on the light receiving surface of the optical detector PD. Then the information recorded on the DVD can be read using the output signal of the optical detector PD. In the optical pickup apparatus PU1, at the time of information recording/reproduction using the DVD, light is emitted from the hologram laser LD3. The divergent light flux from the hologram laser LD3 is reflected by the dichroic prism DP, and is converted into the finite divergent light flux having an angle of divergence of θ3 by the coupling lens CUL. The light flux then passes through the λ/4 wave plate QWP. After the diameter of the light flux has been controlled by an aperture (not illustrated), the objective lens OBJ causes the light to form a spot on the information recording surface through the protective layer of the DVD. The objective lens OBJ conducts focusing and tracking through the biaxial actuator (not illustrated) arranged on the periphery. The reflected light flux having been modulated by the information pit on the information recording surface of the CD again passes through the objective lens OBJ and λ/4 wave plate QWP, and is reflected the coupling lens CUL and dichroic prism DP. Then the light is converged on the light receiving surface of the optical detector inside the hologram laser LD3. Then the information recorded on the CD can be read using the output signal of the optical detector. EXAMPLE The following describes the preferred example of the embodiment. In the following description (including the lens data), the power multiplier of 10 (e.g., 2.5×10−3) will be expressed in terms of E (e.g., 2.5E−3). The optical surface of the objective optical system is formed on the axially symmetric aspherical surface around the optical axis, defined by the mathematical expression obtained by substituting the coefficient of the Table into the mathematical formula 1. z=(y2/γ)/[1+√{square root over ( )}{1−(K+1) (y/γ)2}]+A4y4+A6y6+A8y8+A10y10+A12y12+A14y14+A16y16+A18y18+A20y20 [Mathematical Formula 1] z: Shape of aspherical surface (distance along the optical axis from the plane surface bordering on the vertex of surface of a aspherical surface) y: Distance from optical axis γ: Curvature radius K: Cornic coefficient A4, A6, A8, A10, A12, A14, A16, A18, A20: Aspherical surface coefficient The difference in optical path applied to the light flux of each wavelength by the diffraction structure (phase structure) is defined by the mathematical expression obtained by substituting the coefficient of the Table into the function of optical path difference of the mathematical formula 2. φ=dor×λ/λB×(C2y2+C4y4+C6y6+C8y8+C10y10) [Mathematical Formula 2] where φ: Function of optical path difference λ: Wavelength of light flux entering the diffracted structure λB: Blaze wavelength dor: Order of diffraction of the diffracted light for recording/reproduction using the optical disk y: Distance from optical axis C2, C4, C6, C8, C10: Optical path difference function coefficient Example 1 Table 1 shows the lens data of Example 1, wherein the optical magnification m1 in the light flux of wavelength λ1 is 0.035, and the optical magnification m2 in the light flux of wavelength λ2 is 0.035, and therefore, the difference is zero. In this case, the chromatic aberration ΔfB (λm/nm) in the composite system made up of a coupling lens and objective lens is −0.12. TABLE 1 Example 1 i-th surface ri di (407 nm) ni (407 nm) di (655 nm) ni (655 nm) di (785 nm) ni (785 nm) 0 0.00 0.00 0.00 1 ∞ 29.21 29.21 18.21 2 35.7364 1.70 1.5598 1.70 1.5407 1.70 1.5372 3 −16.1301 10.00 1.0 10.00 1.0 10.00 1.0 4 ∞ 0.00 −0.17 0.08 5 ∞ 0.00 0.00 0.00 (Aperture diameter) 6 2.1231 1.76 1.5598 1.76 1.5407 1.76 1.5372 7 −26.7426 1.54 1.0 1.71 1.0 1.46 1.0 8 ∞ 0.60 1.6187 0.60 1.5775 1.20 1.6187 9 ∞ 0.00 1.0 0.00 1.0 0.00 1.0 * di indicates the displacement from the i-th surface to the i + 1-th surface 3rd surface Aspherical surface coefficient κ −1.0002E+00 A4 1.9416E−05 A6 0.0000E+00 6th surface Aspherical surface coefficient κ −4.9315E−01 A4 1.6515E−03 A6 5.5701E−04 A8 −9.3443E−06 A10 −3.0976E−05 A12 1.1487E−05 A14 −1.3823E−06 7th surface Aspherical surface coefficient κ −1.9917E+01 A4 1.0542E−02 A6 −1.4002E−03 A8 −1.6501E−04 A10 7.2173E−05 A12 −1.0340E−05 A14 6.3473E−07 Optical path difference function (HD DVD secondary, DVD: primary, CD: primary) λB 407 nm C2 −1.4955E−03 Optical path difference function (HD DVD secondary, DVD: primary, CD: primary) λB 395 nm C2 −1.0985E−02 C4 −3.4938E−04 C6 8.3919E−05 C8 −3.9176E−05 C10 4.3351E−06 Example 2 Table 2 shows the lens data of Example 2, wherein the optical magnification m1 in the light flux of wavelength λ1 is 0.045, and the optical magnification m2 in the light flux of wavelength λ2 is 0.026, and Therefore, the difference is 0.019. In this case, the chromatic aberration ΔfB (μm/nm) in the composite system made up of a coupling lens and objective lens is 0.06. TABLE 2 Example 2 i-th surface ri di (408 nm) ni (408 nm) di (660 nm) ni (660 nm) di (784 nm) ni (784 nm) 0 0.00 0.00 0.00 1 ∞ 18.08 18.08 11.47 2 46.2814 1.00 1.5583 1.00 1.5392 1.00 1.5359 3 −18.4386 10.00 1.0 10.00 1.0 10.00 1.0 4 ∞ 0.00 −0.10 0.13 5 ∞ 0.00 0.00 0.00 (Aperture diameter) 6 1.4188 1.37 1.5583 1.37 1.5392 1.37 1.5359 7 −8.0337 1.04 1.0 1.14 1.0 0.91 1.0 8 ∞ 0.60 1.6183 0.60 1.5772 1.20 1.5707 9 ∞ 0.00 1.0 0.00 1.0 0.00 1.0 * di indicates the displacement from the i-th surface to the i + 1-th surface 3rd surface Aspherical surface coefficient κ −9.9948E−01 A4 3.2017E−05 A6 0.0000E+00 6th surface Aspherical surface coefficient κ −5.3111E−01 A4 1.8302E−03 A6 1.9628E−03 A8 7.2388E−04 A10 −1.7748E−03 A12 1.0782E−03 A14 −2.6515E−04 7th surface Aspherical surface coefficient κ −3.0573E+01 A4 2.7016E−02 A6 −7.8590E−03 A8 −2.2641E−05 A10 −8.4844E−04 A12 5.6544E−04 A14 −9.8702E−05 Optical path difference function (HD DVD secondary, DVD: primary, CD: primary) λB 407 nm C2 7.1665E−03 Optical path difference function (HD DVD secondary, DVD: primary, CD: primary) λE 395 nm C2 1.0763E−03 C4 −4.9838E−04 C6 6.5400E−04 C8 −5.0621E−04 C10 1.2263E−04 Example 3 Table 3 shows the lens data of Example 3, wherein the optical magnification m1 in the light flux of wavelength λ1 is 0.045, and the optical magnification m2 in the light flux of wavelength λ2 is 0.048, and Therefore, the difference is 0.003. In this case, the chromatic aberration ΔfB (μm/nm) in the composite system made up of a coupling lens and objective lens is −0.11. TABLE 3 Example 3 i-th surface ri di (408 nm) ni (408 nm) di (660 nm) ni (660 nm) di (784 nm) ni (784 nm) 0 0.00 0.00 80.43 1 ∞ 18.23 18.23 0.00 2 21.5799 1.00 1.5583 1.00 1.5392 0.00 3 −9.1747 10.00 1.0 10.00 1.0 0.00 4 ∞ 0.00 −0.11 0.00 5 ∞ 0.00 0.00 0.00 (Aperture diameter) 6 1.6267 1.37 1.5583 1.37 1.5392 1.37 1.5359 7 −18.5764 0.99 1.0 1.10 1.0 0.85 1.0 8 ∞ 0.60 1.6183 0.60 1.5772 1.20 1.5707 9 ∞ 0.00 1.0 0.00 1.0 0.00 1.0 * di indicates the displacement from the i-th surface to the i + 1-th surface 3rd surface Aspherical surface coefficient κ −9.9968E−01 A4 8.6105E−05 A6 0.0000E+00 6th surface Aspherical surface coefficient κ −5.0383E−01 A4 3.5417E−03 A6 2.9664E−03 A8 4.9806E−04 A10 −1.8035E−03 A12 1.0468E−03 A14 −2.3726E−04 7th surface Aspherical surface coefficient κ −1.3473E+00 A4 2.5969E−02 A6 −1.1096E−02 A8 3.6532E−03 A10 −3.3370E−03 A12 1.3039E−03 A14 −1.7821E−04 Optical path difference function (HD DVD secondary, DVD: primary) λB 407 nm C2 −3.8522E−03 Optical path difference function (HD DVD secondary, DVD: primary, CD: primary) λB 395 nm C2 −1.7549E−02 C4 −1.3939E−03 C6 8.3469E−04 C8 −5.8599E−04 C10 1.1907E−04 Example 4 Table 4 shows the lens data of Example 4, wherein the optical magnification m1 in the light flux of wavelength λ1 is 0.035, and the optical magnification m2 in the light flux of wavelength λ2 is 0.027, and therefore, the difference is 0.008. In this case, the chromatic aberration ΔfB (μm/nm) in the composite system made up of a coupling lens and objective lens is 0.03. TABLE 4 Example 4 i-th surface ri di (407 nm) ni (407 nm) di (655 nm) ni (655 nm) di (785 nm) ni (785 nm) 0 0.00 0.00 114.63 1 ∞ 29.18 29.18 0.00 2 39.7962 1.70 1.5598 1.70 1.5407 0.00 3 −23.4207 10.00 1.0 10.00 1.0 0.00 4 ∞ 0.00 −0.14 0.00 5 ∞ 0.00 0.00 0.00 (Aperture diameter) 6 2.0243 1.76 1.5598 1.76 1.5407 1.76 1.5372 7 −16.9457 1.57 1.0 1.71 1.0 1.49 1.0 8 ∞ 0.60 1.6187 0.60 1.5775 1.20 1.6187 9 ∞ 0.00 1.0 0.00 1.0 0.00 1.0 * di indicates the displacement from the i-th surface to the i + 1-th surface 3rd surface Aspherical surface coefficient κ 5.0842E−01 A4 3.1889E−05 A6 0.0000E+00 6th surface Aspherical surface coefficient κ −5.1670E−01 A4 4.4448E−04 A6 1.1441E−03 A8 −1.4612E−04 A10 −5.3029E−05 A12 2.3494E−05 A14 −3.2223E−06 7th surface Aspherical surface coefficient κ −8.5805E+01 A4 8.8415E−03 A6 −8.6964E−04 A8 −4.2338E−04 A10 9.4844E−05 A12 −6.6661E−06 A14 −7.4638E−09 Optical path difference function (HD DVD secondary, DVD: primary) λB 407 nm C2 1.5984E−03 Optical path difference function (HD DVD secondary, DVD: primary, CD: primary) λB 395 nm C2 −5.8764E−03 C4 −4.9147E−04 C6 2.9116E−04 C8 −1.0284E−04 C10 1.2038E−05 Table 5 summarizes the numerical values given in the examples. TABLE 5 Example 1 Example 2 Example 3 Example 4 HD Composite Magnification (mG) −0.112 −0.143 −0.143 −0.112 system Chromatic −0.12 0.06 −0.11 0.03 aberration (ΔfB) [μm/nm] Coupling Focal distance 22.8 14.2 14.2 22.8 [mm] Objective Focal distance 3.10 2.30 2.30 3.10 (f1) [mm] NA 0.65 0.65 0.65 0.65 Magnification 0.035 0.045 0.045 0.035 (m1) Chromatic −0.42 0.48 −0.49 0.08 aberration [μm/nm] DVD Composite Magnification −0.118 −0.138 −0.151 −0.115 system (mG) Coupling Focal distance 23.1 15.7 14.2 24.2 [mm] Objective Focal distance 3.28 2.37 2.44 3.25 [mm] NA 0.65 0.65 0.65 0.65 Magnification 0.035 0.026 0.048 0.027 (m2) ΔfB + 1.29 × 10−4 × f1 × (m2 − m1) −0.120 0.060 −0.110 0.030 d1 [mm] 0.00149 0.00152 0.00157 0.00149 (Objective lens) d2 [mm] 0.00145 0.00141 0.00146 0.00145 (Coupling lens)
|
G
|
G11
|
G11B
|
7
|
00
|
|||
11766981
|
US20080045554A1-20080221
|
PURINONE DERIVATIVES AS HM74A AGONISTS
|
ACCEPTED
|
20080206
|
20080221
|
[]
|
A61K31495
|
["A61K31495", "A61P300", "C07D23900"]
|
7511050
|
20070622
|
20090331
|
514
|
218000
|
61458.0
|
LEESER
|
ERICH
|
[{"inventor_name_last": "Zheng", "inventor_name_first": "Changsheng", "inventor_city": "Wilmington", "inventor_state": "DE", "inventor_country": "US"}, {"inventor_name_last": "Xue", "inventor_name_first": "Chu-Biao", "inventor_city": "Hockessin", "inventor_state": "DE", "inventor_country": "US"}, {"inventor_name_last": "Cao", "inventor_name_first": "Ganfeng", "inventor_city": "Bear", "inventor_state": "DE", "inventor_country": "US"}, {"inventor_name_last": "Xia", "inventor_name_first": "Michael", "inventor_city": "Wilmington", "inventor_state": "DE", "inventor_country": "US"}, {"inventor_name_last": "Wang", "inventor_name_first": "Anlai", "inventor_city": "Wilmington", "inventor_state": "DE", "inventor_country": "US"}, {"inventor_name_last": "Ye", "inventor_name_first": "Hai", "inventor_city": "Newark", "inventor_state": "DE", "inventor_country": "US"}, {"inventor_name_last": "Metcalf", "inventor_name_first": "Brian", "inventor_city": "Moraga", "inventor_state": "CA", "inventor_country": "US"}]
|
The present invention relates to purinone derivatives which are agonists of the HM74a receptor. Further provided are compositions and methods of using the compounds herein, and their pharmaceutically acceptable salts for the treatment of disease.
|
1. A compound of Formula I: or pharmaceutically acceptable salt or prodrug thereof, wherein: a dashed line indicates an optional bond; X is N, CR3a, CR4aR5a, or NR6a; Y is N, CR3b, CR4bR5b, or NR6b; L is —(C1-6 alkylene)-(Q1)m-(C1-6 alkylene)p-(Q2)q-(C1-6 alkylene)r-, optionally substituted with 1, 2, 3, 4, or 5 RL1, wherein if m and q are both 1, then p is 1; R1 is H, C1-10 alkyl, C2-10alkenyl, C2-10alkynyl, or Cy, wherein said C1-10 alkyl, C2-10alkenyl, or C2-10alkynyl is optionally substituted with 1, 2, 3, 4, or 5 RL2; R2 is halo, cyano, C1-3 haloalkyl, Z, SRA, or a moiety having the formula: R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, or C2-6 alkynyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd; R4a, R4b, R5a, and R5b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; R6a and R6b are independently selected from H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, Cy2, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; RL1 and RL2 are independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, CN, NO2, ORa2, SRa2, C(O)Rb2C(O)NRc2Rd2, C(O)ORa2, OC(O)Rb2, OC(O)NRc2Rd2, NRc2Rd2, NRc2C(O)Rb2, NRc2C(O)NRc2Rd2, NRc2C(O)ORa2, S(O)Rb2, S(O)NRc2Rd2, S(O)2Rb2, NRc2S(O)2Rb2, and S(O)2NRc2Rd2; R2a is H, C1-6 alkyl, C2-6 alkenyl, C2-10alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy4, CN, NO2, C(O)Rb6, C(O)NRc6Rd6, or C(O)ORa6; Cy is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa3, SRa3, C(O)Rb3, C(O)NRc3Rd3, C(O)ORa3, OC(O)Rb3, OC(O)NRc3Rd3, NRc3Rd3, NRc3C(O)Rb3, NRc3C(O)ORa3, S(O)Rb3, S(O)NRc3Rd3, S(O)2Rb3, and S(O)2NRc3Rd3; Cy1 and Cy2 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)b4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, or C2-4 alkynyl is optionally substituted with 1, 2, or 3 substituents independently selected from CN, NO2, halo, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3; Cy3 and Cy4 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; Z is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; RA is H or C1-4 alkyl; Q1 and Q2 are independently selected from O, S, NH, CH2, CO, CS, SO, SO2, OCH2, SCH2, NHCH2, CH2CH2, COCH2, CONH, COO, SOCH2, SONH, SO2CH2, and SO2NH; Ra and Ra1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Ra2, Ra3, Ra4, Ra5, and Ra6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rb and Rb1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rb2, Rb3, Rb4, Rb5, and Rb6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rc and Rd are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc and Rd together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc1 and Rd1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc1 and Rd1 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc2 and Rd2 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc2 and Rd2 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc3 and Rd3 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc3 and Rd3 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc4 and Rd4 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc4 and Rd4 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc5 and Rd5 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc5 and Rd5 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and Rc6 and Rd6 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc6 and Rd6 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and m, p, q, and r are independently selected from 0 and 1, with the provisos: (a) when XY is CR4aR5a═CR4bR5b then R2 is other than halo, C1-3 haloalkyl, Z or SRA; (b) when XY is CR3a═N, then R2 is other than Z; (c) when XY is N═CR3b and R3b is H or unsubstituted aryl, then R2 is other than unsubstituted aryl; (d) when XY is N═N, then R2 is other than aryl; and (e) when XY is CR3a═CR3b, then -L-R1 is other than methyl. 2. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein X is N. 3. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein X is CH. 4. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein Y is CR3b. 5. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein Y is CH. 6. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein Y is C-Me. 7. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein X is CH and Y is N. 8. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRc(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd. 9. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NR C(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd. 10. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, and NRcC(O)Rb. 11. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R3a and R3b are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, Cy1, halo, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, halo, ORa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb. 12. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein: at least one of R3a and R3b is selected from Cy1; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. 13. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein at least one of R3a and R3b is selected from C1-6 alkyl and C1-6 haloalkyl, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from C(O)NRcRd, C(O)ORa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb. 14. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein: at least one of R3a and R3b is selected from C1-3 alkyl, wherein said C1-3 alkyl is substituted with Cy1 and optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa6, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6. 15. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein: at least one of R3a and R3b is selected from C1-3 alkyl, wherein said C1-3 alkyl is substituted with Cy1 and optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. 16. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein: at least one of R3a and R3b is independently selected from C1-3 alkyl, wherein said C1-3 alkyl is substituted with Cy1 and optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each substituted with 1 or 2 R7 and optionally substituted by 1, 2, or 3 R8; R7 is, at each occurrence, independently selected from Cy3 and C1-4 alkyl, wherein said C1-4 alkyl is substituted with 1 or 2 Cy3 and optionally substituted with 1 or 2 substituents independently selected from halo and ORa4; R8 is, at each occurrence, independently selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, and C(O)ORa4; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. 17. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, and C1-6 haloalkyl. 18. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R3a and R3b are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl. 19. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R3b is heteroaryl optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from aryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa6, and SRa6. 20. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R3b is thiazolyl that is optionally substituted with phenyl, wherein said phenyl is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from OH and halo. 21. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4R4d, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from ORa4 and Cy3. 22. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein m and q are 0. 23. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R1 is H or C1-10 alkyl. 24. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein -L-R1 is C1-10 alkyl. 25. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein -L-R1 is C4-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 substitutents each independent selected from halo, OH, and CN. 26. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein -L-R1 is butyl or pentyl. 27. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: 28. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 is halo, cyano, C1 haloalkyl, Z, or, SRA. 29. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 is halo, cyano, or C1 haloalkyl. 30. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 is halo or C1 haloalkyl. 31. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 is Cl, Br, or CF3. 32. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 is Cl or Br. 33. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 is Br. 34. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 a moiety having the formula: 35. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 is S-Me. 36. The compound of claim 1, or pharmaceutically acceptable salt thereof, wherein R2 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, and ORa4. 37. The compound of claim 1, or pharmaceutically acceptable salt thereof, having Formula II: 38. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein R3b is selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(d)2NRcRd. 39. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein R3b is selected from H, C1-6 alkyl, C1-6 haloalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, halo, ORa, NRcRd, NRcC(O)NRcRd and NRcC(O)Rb. 40. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: R3b is Cy1; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. 41. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein R3b is C1-6 alkyl or C1-6 haloalkyl, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from C(O)NRcRd, C(O)ORa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb. 42. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: R3b is selected from C1-3 alkyl, wherein said C1-3 alkyl is substituted with Cy1 and optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each substituted with 1 or 2 R7 and optionally substituted by 1, 2, or 3 R8; R7 is, at each occurrence, independently selected from Cy3 and C1-4 alkyl, wherein said C1-4 alkyl is substituted with 1 or 2 Cy3 and optionally substituted with 1 or 2 substituents independently selected from halo and ORa4; R8 is, at each occurrence, independently selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, and C(O)ORa4; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. 43. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: L is C1-6 alkylene; R1 is H or C1-3 alkyl, wherein said C1-3 alkyl is optionally substituted with 1, 2, 3, 4, or 5 RL2; and RL2 is, at each occurrence, independently selected from halo, CN, NO2, and ORa2; 44. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein R2 is halo or C1-3 haloalkyl. 45. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein R2 is Br. 46. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: L is C1-18alkylene; R3b is H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, or NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd; and R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: 47. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: L is C1-18 alkylene; R3b is H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, or NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, and NRcC(O)Rb; and R2 is halo, cyano, C1 haloalkyl, Z, or, SRA. 48. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: L is C1-18 alkylene; R3b is heteroaryl that is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from aryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa6, SRa6, and R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: 49. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: L is C1-18 alkylene; R3b is thiazolyl that is optionally substituted with phenyl, wherein said phenyl is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from OH and halo; and R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: 50. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: L is C1-18alkylene; R3b is H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, or C1-6 haloalkyl; and R2 is halo, cyano, or C1 haloalkyl. 51. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: R3b is C1-6 alkyl, C1-6 haloalkyl, or Cy1, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, halo, ORa, SRa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb; L is C1-6 alkylene optionally substituted with 1, 2, 3, 4, or 5 RL1; R1 is H or C1-3 alkyl, wherein said C1-3 alkyl is optionally substituted with 1, 2, 3, 4, or 5 RL2; RL1 and RL2 are, at each occurrence, independently selected from halo, CN, NO2, and OR and R2 is halo or C1-3 haloalkyl. 52. The compound of claim 51 wherein: -L-R1 is C2-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo; R2 is halo. 53. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: the compound has Formula Ia: LA is C1-3 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa. 54. The compound of claim 37, or pharmaceutically acceptable salt thereof, wherein: the compound has Formula IIb: LA is C1-3 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; LB is C1-4 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo and ORa4; and t1 is 0 or 1. 55. The compound of claim 1, or pharmaceutically acceptable salt thereof, having Formula III: 56. The compound of claim 1, or pharmaceutically acceptable salt thereof, having Formula IV: 57. The compound of claim 1 selected from: 3-methyl-9-pentyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 9-butyl-3-methyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 9-pentyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 9-butyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-methyl-9-butyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-chloro-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; and 7-chloro-3-methyl-9-butyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; or pharmaceutically acceptable salt thereof. 58. The compound of claim 1 selected from: 7-bromo-3-(methylthio)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(methylsulfinyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(methylsulfonyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-hydroxy-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-butyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-butyl-3-(methoxymethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-phenyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-pyridin-3-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-pyridin-4-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-pyridin-2-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(1,3-thiazol-2-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-propyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-[(dimethylamino)methyl]-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-methyl-9-pentyl-7-(1,3-thiazol-2-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-methyl-7-(methylthio)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-methyl-9-pentyl-7-phenyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-methyl-9-pentyl-7-pyridin-4-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-(3,5-dimethylisoxazol-4-yl)-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-cyclopropyl-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-methyl-7-(1-methyl-1H-pyrazol-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-methyl-9-pentyl-7-(4H-1,2,4-triazol-4-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-methyl-9-pentyl-7-(1H-1,2,4-triazol-1-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-cyclobutyl-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(4-methoxyphenyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(4-(trifluoromethyl)phenyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(4-methoxybenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(3-bromobenzyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(3-pyrimidin-5-ylbenzyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-pyrimidin-4-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-pyrazin-2-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-cyclopropyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(dimethylamino)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(3,3,3-trifluoropropyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(2-phenylethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(pyridine-4-ylmethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(2-pyridine-3-ylethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(1-phenylcyclopropyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(2-methylpyridin-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(3-fluoropyridin-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(3-fluorobenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(3-methoxybenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(1,3-oxazol-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-isoxazol-3-yl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(1-methyl-1H-imidazol-2-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(3-pyridin-4-ylbenzyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(2-methoxybenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 1-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)cyclopropanecarboxamide; 1-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)cyclopropanecarboxylic acid; 7-bromo-9-pentyl-3-[1-(trifluoromethyl)cyclopropyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(2,3-dihydro-1,4-benzodioxin-6-ylmethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-[(3-oxo-3,4-dihydro-2H-1,4-benzoxazin-6-yl)methyl])-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-Benzyl-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 6-bromo-4-pentyl-4,7-dihydro-8H-tetrazolo[1,5-a]purin-8-one; 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)propanoic acid; 7-bromo-3-(3-morpholin-4-yl-3-oxopropyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; N-benzyl-3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)propanamide; 7-bromo-3-(3-oxo-3-pyrrolidin-1-ylpropyl)-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-3-yl)-N-methylpropanamide; 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)-N-(2-phenylethyl)propanamide; 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)-N-(pyridin-4-ylmethyl)propanamide; 3-[2-(3-benzyl-1,2,4-oxadiazol-5-yl)ethyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-{2-[3-(2-thienylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(2-{3-[4-(trifluoromethyl)benzyl]-1,2,4-oxadiazol-5-yl}ethyl)-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-3-{2-[3-(4-fluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-{2-[3-(4-methoxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-9-pentyl-3-{2-[3-(pyridine-4-ylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(2-{3-[3-(trifluoromethyl)benzyl]-1,2,4-oxadiazol-5-yl}ethyl)-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-9-pentyl-3-(2-{3-[2-(trifluoromethyl)benzyl]-1,2,4-oxadiazol-5-yl}ethyl)-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-9-pentyl-3-{2-[3-(pyridine-3-ylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-{2-[3-(2-phenylethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-{2-(3-phenyl-1,2,4-oxadiazol-5-yl)ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(3-fluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one 7-bromo-3-{2-[3-(4-chlorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-[2-(3-benzyl-1,2,4-oxadiazol-5-yl)ethyl]-7-chloro-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(2-fluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(2-methoxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-3-[2-(3-ethyl-1,2,4-oxadiazol-5-yl)ethyl]-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-3-{2-[3-(3-methoxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-3-{2-[3-(3-methylbenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-3-{2-[3-(2,4-difluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-3-{2-[3-(3,5-difluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-9-pentyl-3-{2-[3-(3-thienylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-{2-[3-(1-phenylcyclopropyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one; 7-bromo-9-pentyl-3-{2-[3-(pyridine-2-ylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-[(2R)-2-(3-benzyl-1,2,4-oxadiazol-5-yl)propyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(2-{3-[(4-methyl-1,3-thiazol-2-yl)methyl]-1,2,4-oxadiazol-5-yl}ethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(2-methylbenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-(2-{3-[hydroxy(phenyl)methyl]-1,2,4-oxadiazol-5-yl}ethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(2,5-difluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-{2-[3-(pyrimidin-5-ylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-butyl-3-{2-[3-(2-fluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-[2-(3-benzyl-1,2,4-oxadiazol-5-yl)ethyl]-9-pentyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-[2-(3-benzyl-1,2,4-oxadiazol-5-yl)ethyl]-7-cyclopropyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-methyl-9-pentyl-7-[1-(trifluoromethyl)cyclopropyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-(2,2-difluorocyclopropyl)-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-(1-hydroxycyclopropyl)-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[2-(5-phenyl-1,3,4-oxadiazol-2-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-[2-(5-benzyl-1,3,4-oxadiazol-2-yl)ethyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; N-[(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)methyl]benzamide; N-[(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)methyl]acetamide; 3-(1-benzylpiperidin-4-yl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-[3-(3-benzyl-1,2,4-oxadiazol-5-yl)propyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 2-bromo-4-pentyl-1,4-dihydro-9H-[1,2,4]triazolo[1,5-a]purin-9-one; 3-methyl-9-pentyl-7-(1,3-thiazol-4-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[2-(3-pyrazin-2-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate; 7-bromo-9-pentyl-3-[2-(3-pyridin-3-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate; 7-bromo-9-pentyl-3-[2-(3-pyridin-2-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate; 7-bromo-9-pentyl-3-[2-(3-pyridin-4-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate; 7-bromo-9-pentyl-3-{2-[3-(2-thienyl)-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-(1,3-benzodioxol-5-ylmethyl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; and 7-bromo-9-pentyl-3-pyrimidin-5-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; or pharmaceutically acceptable salt thereof. 59. The compound of claim 1 selected from: 7-bromo-9-pentyl-3-[3-(3-phenyl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[2-(3-pyridin-2-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[2-(3-pyridin-4-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-{2-[3-(2-thienyl)-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-(1,3-benzodioxol-5-ylmethyl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-pyrimidin-5-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[3-(3-phenyl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[3-(3-pyridin-2-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[3-(3-pyridin-3-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[3-(3-pyridin-4-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[3-(3-pyrazin-2-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-{3-[3-(2-thienyl)-1,2,4-oxadiazol-5-yl]propyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-{3-[3-(3-thienyl)-1,2,4-oxadiazol-5-yl]propyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-(3-{3-[3-(trifluoromethyl)phenyl]-1,2,4-oxadiazol-5-yl}propyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(4-methoxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[3-(3-pyrimidin-2-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(2-methoxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(3-methoxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(4-ethynylphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(1H-indol-5-yl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(1H-indol-3-yl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(6-methoxypyridin-3-yl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-{3-[3-(4-aminopyrimidin-5-yl)-1,2,4-oxadiazol-5-yl]propyl}-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-3-[3-(4-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]propyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-3-[3-(2-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]propyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-3-[3-(3-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]propyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(4-hydroxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(2-hydroxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(3-hydroxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[3-(4-phenyl-1H-pyrazol-1-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[3-(4-phenyl-1H-imidazol-1-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-3-[4-(5-fluoro-2-hydroxyphenyl)-1H-pyrazol-1-yl]propyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-2-[5-(4-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-2-[5-(4-hydroxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-2-[5-(3-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-2-[5-(3-hydroxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-2-[5-(2-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-2-[5-(2-hydroxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-2-[5-(2-chloro-4-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-2-[5-(2-chloro-4-hydroxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[2-(5-pyridin-4-yl-1,2,4-oxadiazol-3-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[2-(5-pyridin-3-yl-1,2,4-oxadiazol-3-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-pentyl-3-[2-(5-pyridin-2-yl-1,2,4-oxadiazol-3-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(4-methoxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(3-methoxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(2-methoxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(4-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(3-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(2-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(2-chloro-4-methoxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{2-[3-(2-chloro-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 3-[2-(5-benzyl-1,2,4-oxadiazol-3-yl)ethyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(2-chloro-4-methoxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-{3-[3-(2-chloro-4-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-4-methoxybenzamide; N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]benzamide; N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]isonicotinamide; 7-bromo-9-pentyl-3-[2-(pyrimidin-2-ylamino)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]nicotinamide; N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]pyridine-2-carboxamide; 3-amino-N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]isonicotinamide; N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-2-methylisonicotinamide; N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-N′-phenylurea; N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-4-hydroxybenzamide; 3-methyl-7-(pentafluoroethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-methyl-9-(4,4,4-trifluorobutyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-3-methyl-9-(5,5,5-trifluoropentyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; 7-bromo-9-(4-fluorobutyl)-3-methyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one; and 7-bromo-9-(4-fluoropentyl)-3-methyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one, or pharmaceutically acceptable salt thereof. 60. A composition comprising a compound of claim 1, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 61. A composition comprising a compound of claim 31, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 62. A composition comprising a compound of claim 32, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 63. A composition comprising a compound of claim 37, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 64. A composition comprising a compound of claim 39, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 65. A composition comprising a compound of claim 41, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 66. A composition comprising a compound of claim 45, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 67. A composition comprising a compound of claim 52, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 68. A composition comprising a compound of claim 53, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 69. A composition comprising a compound of claim 54, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 70. A composition comprising a compound of claim 55, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 71. A composition comprising a compound of claim 56, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 72. A composition comprising a compound of claim 57, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 73. A composition comprising a compound of claim 58, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 74. A composition comprising a compound of claim 59, or pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier. 75. A method of modulating HM74a receptor comprising contacting said HM74a receptor with a compound of Formula I: or pharmaceutically acceptable salt or prodrug thereof, wherein: a dashed line indicates an optional bond; X is N, CR3a, CR4aR5a, or NR6a; Y is N, CR3b, CR4bR5b, or NR6b; L is —(C1-6 alkylene)-(Q1)m-(C1-6 alkylene)p-(Q2)q-(C1-6 alkylene)r-, optionally substituted with 1, 2, 3, 4, or 5 RL1, wherein if m and q are both 1, then p is 1; R1 is H, C1-10 alkyl, C2-10alkenyl, C2-10alkynyl, or Cy, wherein said C1-10 alkyl, C2-10alkenyl, or C2-10 alkynyl is optionally substituted with 1, 2, 3, 4, or 5 RL2; R2 is halo, cyano, C1-3 haloalkyl, Z, SRA, or a moiety having the formula: R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, or C2-6 alkynyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd; R4a, R4b, R5a, and R5b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORb1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; R6a and R6b are independently selected from H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, Cy2, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; RL1 and RL2 are independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, CN, NO2, ORa2, SRa2, C(O)Rb2, C(O)NRc2Rd2, C(O)ORa2, OC(O)Rb2, OC(O)NRc2Rd2, NRc2Rd2, NRc2C(O)Rb2, NRc2C(O)NRc2Rd2, NRc2C(O)ORa1, S(O)Rb2, S(O)NRc2Rd2, S(O)2Rb2, NRc2S(O)2Rb2, and S(O)2NRc2Rd2; R2a is H, C1-6 alkyl, C2-6 alkenyl, C2-10alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy4, CN, NO2, C(O)Rb6, C(O)NRc6Rd6, or C(O)ORa6; Cy is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa3, SRa3, C(O)Rb3, C(O)NRc3Rd3, C(O)ORa3, OC(O)Rb3, OC(O)NRc3Rd3, NRc3Rd3, NRc3C(O)Rb3, NRc3C(O)ORa3, S(O)Rb3, S(O)NRc3Rd3, S(O)2Rb3, and S(O)2NRc3Rd3; Cy1 and Cy2 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)b4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, or C2-4 alkynyl is optionally substituted with 1, 2, or 3 substituents independently selected from CN, NO2, halo, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3; Cy3 and Cy4 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa6, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; Z is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa6, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; RA is H or C1-4 alkyl; Q1 and Q2 are independently selected from O, S, NH, CH2, CO, CS, SO, SO2, OCH2, SCH2, NHCH2, CH2CH2, COCH2, CONH, COO, SOCH2, SONH, SO2CH2, and SO2NH; Ra and Ra1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rc5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Ra2, Ra3, Ra4, Ra, and Ra6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rb and Rb1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rb2, Rb3, Rb4, Rb5, and Rb6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rc and Rd are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rd5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc and Rd together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc1 and Rd1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc4Rd5. NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc1 and Rd1 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc2 and Rd2 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc2 and Rd2 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc3 and Rd3 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc3 and Rd3 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc4 and Rd4 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc4 and Rd4 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc5 and Rd5 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc5 and Rd5 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and Rc6 and Rd6 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc6 and Rd6 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and m, p, q, and r are independently selected from 0 and 1. 76. The method of claim 75 wherein said modulating is agonizing. 77. A method of treating a disease in a patient, wherein said disease is associated with HM74a receptor, comprising administering to said patient a therapeutically effective amount of a compound of Formula I: or pharmaceutically acceptable salt or prodrug thereof, wherein: a dashed line indicates an optional bond; X is N, CR3a, CR4aR5a, or NR6a; Y is N, CR3b, CR4bR5b, or NR6b; L is —(C1-6 alkylene)-(Q1)m-(C1-6 alkylene)p-(Q2)q-(C1-6 alkylene)r-, optionally substituted with 1, 2, 3, 4, or 5 RL1, wherein if m and q are both 1, then p is 1; R1 is H, C1-10alkyl, C2-10alkenyl, C2-10alkynyl, or Cy, wherein said C1-10 alkyl, C2-10alkenyl, or C2-10 alkynyl is optionally substituted with 1, 2, 3, 4, or 5 RL2; R2 is halo, cyano, C1-3 haloalkyl, Z, SRA, or a moiety having the formula: R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, or C2-6 alkynyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd; R4a, R4b, R5a, and R5b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; R6a and R6b are independently selected from H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, Cy2, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; RL1 and RL2 are independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, CN, NO2, ORa2, SRa2, C(O)Rb2, C(O)NRc2Rd2, C(O)ORa2, OC(O)Rb2, OC(O)NRc2Rd2, NRc2Rd2, NRc2C(O)Rb2, NRc2C(O)NRc2Rd2, NRc2C(O)ORa2, S(O)Rb2, S(O)NRc2Rd2, S(O)2Rb2, NRc2S(O)2Rb2, and S(O)2NRc2Rd2; R2a is H, C1-6 alkyl, C2-6 alkenyl, C2-10alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy4, CN, NO2, C(O)Rb6, C(O)NRc6Rd6, or C(O)ORa6; Cy is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, N2, ORa3, SRa3, C(O)Rb3, C(O)NRc3Rd3, C(O)ORa3, OC(O)Rb3, OC(O)NRc3Rb3, NRc3Rd3, NRc3C(O)Rb3, NRc3C(O)ORa3, S(O)Rb3, S(O)NRc3Rd3, S(O)2Rb3, and S(O)2NRc3Rd3; Cy1 and Cy2 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, or C2-4 alkynyl is optionally substituted with 1, 2, or 3 substituents independently selected from CN, NO2, halo, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)Rb4, S(O)2NRc4Rd4, and Cy3; Cy3 and Cy4 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa, SRa, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; Z is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa6, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; RA is H or C1-4 alkyl; Q1 and Q2 are independently selected from O, S, NH, CH2, CO, CS, SO, SO2, OCH2, SCH2, NHCH2, CH2CH2, COCH2, CONH, COO, SOCH2, SONH, SO2CH2, and SO2NH; Ra and Ra1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)R5b, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Ra2, Ra3, Ra4, Ra5, and Ra6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rb and Rb1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRcsC(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rb2, Rb3, Rb4, Rb5, and Rb6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rc and Rd are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5R5d, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc and Rd together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc1 and Rd1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc1 and Rd1 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc2 and Rd2 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc2 and Rd2 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc3 and Rd3 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc3 and Rd3 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc4 and Rd4 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc4 and Rd4 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc5 and Rd5 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc5 and Rd5 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and Rc6 and Rd6 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc6 and Rd6 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and m, p, q, and r are independently selected from 0 and 1. 78. The method of claim 77 wherein said disease is associated with elevated plasma FFAs. 79. The method of claim 77 wherein said disease is dyslipidemia, highly-active anti-retroviral therapy (HAART)-associated lipodystrophy, insulin resistance, diabetes, metabolic syndrome, atherosclerosis, coronary heart disease, stroke, obesity, elevated body mass index (BMI), elevated waist circumference, non-alcoholic fatty liver disease, hepatic steatosis, or hypertension. 80. A method of treating dyslipidemia, highly-active anti-retroviral therapy (HAART)-associated lipodystrophy, insulin resistance, diabetes, metabolic syndrome, atherosclerosis, coronary heart disease, stroke, obesity, elevated body mass index (BMI), elevated waist circumference, non-alcoholic fatty liver disease, hepatic steatosis, or hypertension in a patient, comprising administering to said patient a therapeutically effective amount of a compound of Formula I: or pharmaceutically acceptable salt or prodrug thereof, wherein: a dashed line indicates an optional bond; X is N, CR3a, CR4a, R5a, or NR6a; Y is N, CR3b, CR4bR5b, or NR6b; L is —(C1-6 alkylene)-(Q1)m-(C1-6 alkylene)p-(Q2)q-(C1-6 alkylene)r-, optionally substituted with 1, 2, 3, 4, or 5 RL1, wherein if m and q are both 1, then p is 1; R1 is H, C1-10alkyl, C2-10alkenyl, C2-10alkynyl, or Cy, wherein said C1-10alkyl, C2-10alkenyl, or C2-10 alkynyl is optionally substituted with 1, 2, 3, 4, or 5 RL2; R2 is halo, cyano, C1-3 haloalkyl, Z, SRA, or a moiety having the formula: R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, or C2-6 alkynyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd; R4a, R4b, R5a, and R5b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, (O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; R6a and R6b are independently selected from H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, Cy2, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1C(O)ORa, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; RL1 and RL2 are independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, CN, NO2, ORa2, SRa2, C(O)Rb2, C(O)NRc2Rd2, C(O)ORa2, OC(O)Rb2, OC(O)NRc2Rd2, NRc2Rd2, NRc2C(O)Rb2, NRc2C(O)NRc2Rd2, NRc2C(O)ORa2, S(O)Rb2, S(O)NRc2Rd2, S(O)2Rb2, NRc2S(O)2Rb2, and S(O)2NRc2Rd2; R2a is H, C1-6 alkyl, C2-6 alkenyl, C2-10alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy4, CN, NO2, C(O)Rb6, C(O)NRc6Rd6, or C(O)ORa6; Cy is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, N2, ORa3, SRa3, C(O)Rb3, C(O)NRc3Rd3, C(O)ORa3, OC(O)Rb3, OC(O)NRc3Rd3, NRc3Rd3, NRc3C(O)Rb3, NRc3C(O)ORa3, S(O)Rb3, S(O)NRc3Rd3, S(O)2Rb3, and S(O)2NRc3Rd3; Cy1 and Cy2 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)b4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, or C2-4 alkynyl is optionally substituted with 1, 2, or 3 substituents independently selected from CN, NO2, halo, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3; Cy3 and Cy4 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa6, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; Z is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa6, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; RA is H or C1-4 alkyl; Q1 and Q2 are independently selected from O, S, NH, CH2, CO, CS, SO, SO2, OCH2, SCH2, NHCH2, CH2CH2, COCH2, CONH, COO, SOCH2, SONH, SO2CH2, and SO2NH; Ra and Ra1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Ra2, Ra3, Ra4, Ra5, and Ra6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rb and Rb1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rb2, Rb3, Rb4, Rb5, and Rb6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rc and Rd are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc and Rd together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc1 and Rd1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc1 and Rd1 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc2 and Rd2 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc2 and Rd2 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc3 and Rd3 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc3 and Rd3 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc4 and Rd4 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc4 and Rd4 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc5 and Rd5 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc5 and Rd1 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and Rc6 and Rd6 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc6 and Rd6 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and m, p, q, and r are independently selected from 0 and 1.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Coronary artery disease (or CAD) is the number one cause of death in the United States (Nature Med 2002, 8:1209-1262). The initiation and progression of CAD involves a complex interplay between multiple physiological processes, including inflammation, lipid homeostasis, and insulin resistance/diabetes mellitus. Multiple clinical studies have now shown that the three primary components of plasma lipids, low-density lipoprotein (or LDL), high-density lipoproteins (or HDL), and triglycerides (or TGs), are causally associated with the propensity to develop atherosclerosis and CAD. Along side other risk factors such as positive family history of CAD, elevated body-mass index, hypertension, and insulin resistance/diabetes mellitus, elevated plasma LDL and/or TG-rich lipoproteins and decreased plasma HDL levels have been defined as major cardiovascular risk factors by the National Cholesterol Education Program Adult Treatment Panel 111 (NCEP ATP III; Am J Cardio 2003, 92: 19i-26i). Accordingly, therapeutic intervention strategies designed to impact these plasma lipid components as well as those that underlie insulin resistance are of great interest to the medical community. In terms of LDL-lowering, drugs of the statin class are structurally similar to the molecule hydroxymethylglutaryl-coenzyme A (HMG-CoA), a biosynthetic precursor of cholesterol. These drugs are competitive inhibitors of the rate-limiting step of cholesterol biosynthesis catalyzed by HMG-CoA reductase. Mechanistically, the statins lower LDL by upregulating the LDL receptor in the liver as well as by reducing the release of LDL into the circulation. As a monotherapy, the statin class of lipid lowering agents can reduce plasma LDL concentrations by 30-60% and triglycerides by 25%, producing a reduction in the incidence of CAD by 25-60% and the risk of death by 30%. Statins do not have an appreciable effect on HDL. A mechanistically distinct agent, Ezetimibe (Zetia, Merck and Co.), also possesses the ability to reduce plasma LDL, however it functions by inhibiting the absorption of cholesterol by the small intestine via antagonism of the NPC1L1 receptor (PNAS 2005, 102: 8132-8137). Monotherapy with Ezetimibe typically lowers LDL by 20%, however when co-formulated with a statin, maximal reductions can exceed 60%. As with the statins, however, Ezetimibe has a negligible effect on plasma HDL. While statins can have a modest impact on circulating triglycerides, PPAR alpha agonists (or fibrates) are far superior in targeting this lipid endpoint. The fibrates function by increasing lipolysis and elimination of triglyceride-rich particles from plasma by activating lipoprotein lipase and reducing production of apolipoprotein C-III (an inhibitor of lipoprotein lipase activity). One such fibrate, Fenofibrate (Tricor, Abott), has been shown in clinical studies to decrease plasma triglyceride levels upwards of 40-60%. Interestingly, the fibrate class of lipid-lowering drugs also has a modest, but significant effect on both LDL (20% reduction) and HDL (10% increase). Currently, the statin class of LDL lowering agents remains the cornerstone of dyslipidemia therapy. Despite the substantial reduction in cardiovascular events that have been achieved with this therapeutic approach, however, the cardio-protection that is afforded to patients by these therapies is still incomplete. It is now clear that therapies that are targeted to increase HDL cholesterol are critical in terms of maximizing patient cardio-protection. The only therapy available to date that has the ability to effectively raise circulating levels of cardio-protective HDL and consequently improve the progression of atherosclerosis in CAD patients is nicotinic acid (niacin or vitamin B 3 ). Nicotinic acid was first reported to modify lipoprotein profiles in 1955 (Altschul et al. Arch Biochem Biophys 1955, 54: 558-559). Its effects are the most broad-spectrum of any available therapy, effectively raising HDL levels (20-30%) as well as lowering circulating plasma LDL (16%) and triglycerides (38%). The clinical significance of this broad-spectrum activity has been revealed in multiple large clinical studies. In the most recent ARBITER 2 (Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol 2; Taylor et al. Circulation 2004, 110: 3512-3517) study, patients on statin therapy were randomized to either placebo or 1000 mg extended release (ER) niacin (Niaspan, Kos Pharmaceuticals). Patients receiving niacin exhibited a statistically significant decrease in carotid intima-media thickness, a validated surrogate cardiovascular end point. This study also revealed a significantly reduced rate of intima-media thickness progression in subjects without detectable insulin resistance. This study indicates the incomplete cardio-protection that is offered by statin therapy and substantiates the utility of nicotinic acid in reducing overall cardiac risk in low-HDL patients. While nicotinic acid has been used clinically to modify lipid profiles for over four decades, the mechanism of action of the compound has remained largely obscure. It has long been known that acute nicotinic acid dosing results in a profound decrease in circulating free fatty acids (FFAs). This anti-lipolytic activity was first hypothesized in 1980 to be mediated by a membrane receptor linked to a decrease in intracellular cAMP (cyclic AMP, or cyclic adenosine monophosphate, or 3′-5′-cyclic adenosine monophosphate) levels (Aktories et al. FEBS Letters 1980, 115: 11-14). This hypothesis was later confirmed and the implied G i/o GPCR-coupling was verified using pertussis toxin sensitivity studies (Aktories et al. FEBS Letters 1983, 156: 88-92). The identification of specific nicotinic acid binding sites on the surface of adipose and spleen cells confirmed the membrane hypothesis and refined, using modern-day techniques, the G-protein coupling of the receptor itself (Lorenzen et al. Mol Pharm 2001, 59: 349-357). This G-protein mediated, anti-lipolytic activity of nicotinic acid was used for two decades to identify and characterize nicotinic acid analogues in terms of their therapeutic potential. Finally, in 2003, two independent groups simultaneously published the cloning of an orphan G i/o -coupled GPCR, HM74a (Wise et al. J Biol Chem 2003, 278: 9869-9874; Tunaru et al. Nat Med 2003, 9: 352-355), which binds to nicotinic acid with high affinity. As predicted, this receptor was shown to be expressed in adipose tissue and spleen, and binds to not only nicotinic acid, but also to the structurally related derivatives that had been previously shown to exhibit adipocyte anti-lipolytic activity. Mice that have been made deficient in the rodent ortholog of HM74a (Puma-g) by homologous recombination resist nicotinic acid-dependent FFA reduction and TG lowering. It is currently hypothesized that the nicotinic acid anti-lipolytic activity is based on the activation of this high affinity GPCR (HM74a), resulting in a decrease in intracellular cAMP and a subsequent attenuation of hormone sensitive lipase (HSL) activity. Decreased adipocyte lipolytic output results in a reduction in circulating FFA and a corresponding reduction in hepatic TGs, very-low density LDL (VLDL), and LDL. The increased levels of HDL arise from an effective reduction of cholesterol ester transfer protein activity due to decreased availability of VLDL acceptor molecules. Beyond impacting lipid levels and lipoprotein profiles, FFAs play fundamental roles in the regulation of glycemic control. It is now recognized that chronically elevated plasma FFA concentrations cause insulin resistance in muscle and liver, and impair insulin secretion (reviewed in Defronzo et al. Int. J. Clin. Prac. 2004, 58: 9-21). In muscle, acute elevations in plasma FFA concentrations can increase intramyocellular lipid content; this can have direct negative effects on insulin receptor signaling and glucose transport. In liver, increased plasma FFAs lead to accelerated lipid oxidation and acetyl-CoA accumulation, the later of which stimulates the rate-limiting steps for hepatic glucose production. In the pancreas, long-term exposure to elevated FFAs has been shown to impair the beta-cell's ability to secrete insulin in response to glucose. This data has driven the hypothesis that adipose tissue FFA release is a primary driver of the underlying pathologies in type 2 diabetes, and strategies designed to reduce FFAs, for example by agonizing HM74A, may prove effective in improving insulin sensitivity and lowering blood glucose levels in patients with type 2 diabetics/metabolic syndrome The utility of nicotinic acid as a hypolipidemic/FFA lowering agent is currently limited by four main factors. First, significant doses of nicotinic acid are required to impact FFA release and improve lipid parameters. Immediate release (IR) nicotinic acid is often dosed at 3-9 g/day in order to achieve efficacy, and ER nicotinic acid (Niaspan) is typically dosed between 1-2 g/day. These high doses drive the second issue with nicotinic acid therapy, hepatotoxicity. One of the main metabolic routes for nicotinic acid is the formation of nicotinamide (NAM). Increased levels of NAM have been associated with elevated liver transaminase which can lead to hepatic dysfunction. This toxicity is particularly problematic for sustained release formulations and results in the need to monitor liver enzymes during the initiation of therapy. Third, high doses of nicotinic acid are associated with severe prostaglandin-mediated cutaneous flushing. Virtually all patients experience flushing when on IR-nicotinic acid at or near the T max of the drug and discontinuation of therapy occurs in 20-50% of individuals. Niaspan, while exhibiting an increased dissolution time, still possesses a flushing frequency of approximately 70%, and this is in spite of the recommended dosing regimen that includes taking Niaspan along with an aspirin after a low-fat snack. Fourth, nicotinic acid therapy often results in FFA rebound, a condition whereby free fatty acid levels are not adequately suppressed throughout the dosing regimen, resulting in a compensatory increase in adipose tissue lipolysis. With immediate release nicotinic acid therapy, this rebound phenomenon is so great that daily FFA AUCs are actually increased after therapy. Such FFA excursions can lead to impaired glycemic control and elevated blood glucose levels, both of which have been shown to occur in some individuals after nicotinic acid therapy. Giving the importance of nicotinic acid in modulating (especially agonizing) HM74a receptor and its limitations, novel small molecules designed to mimic the mechanism of nicotinic acid's action on HM74a offer the possibility of achieving greater HDL, LDL, TG, and FFA efficacy while avoiding adverse effects such as hepatotoxicity and cutaneous flushing. Such therapies are envisoned to have significant impact beyond dyslipidemia to include insulin resistance, hyperglycemia, and associated syndromes by virtue of their ability to more adequately reduce plasma FFA levels during the dosing interval. The present invention is directed to these, as well as other, important ends.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides, inter alia, compounds of Formula I: or pharmaceutically acceptable salts or prodrugs thereof, wherein constituent members are defined herein. The present invention further provides compositions comprising a compound of the invention and at least one pharmaceutically acceptable carrier. The present invention further provides methods of modulating HM74a receptor with a compound of the invention. The present invention further provides methods of agonizing HM74a receptor by contacting the HM74a receptor with a compound of the invention. The present invention further provides methods of treating diseases associated with HM74a receptor. The present invention further provides a compound of the invention for use in therapy. The present invention further provides a compound of the invention for use in the preparation of a medicament for use in therapy. detailed-description description="Detailed Description" end="lead"?
|
This application claims benefit of priority to U.S. provisional patent application Ser. No. 60/815,955 filed Jun. 23, 2006, and to U.S. provisional patent application Ser. No. 60/922,818 filed on Apr. 11, 2007, each of which is hereby incorporated in its entirety. FIELD OF THE INVENTION The present invention relates to agonists of the HM74a receptor, compositions thereof and methods of using the same. BACKGROUND OF THE INVENTION Coronary artery disease (or CAD) is the number one cause of death in the United States (Nature Med 2002, 8:1209-1262). The initiation and progression of CAD involves a complex interplay between multiple physiological processes, including inflammation, lipid homeostasis, and insulin resistance/diabetes mellitus. Multiple clinical studies have now shown that the three primary components of plasma lipids, low-density lipoprotein (or LDL), high-density lipoproteins (or HDL), and triglycerides (or TGs), are causally associated with the propensity to develop atherosclerosis and CAD. Along side other risk factors such as positive family history of CAD, elevated body-mass index, hypertension, and insulin resistance/diabetes mellitus, elevated plasma LDL and/or TG-rich lipoproteins and decreased plasma HDL levels have been defined as major cardiovascular risk factors by the National Cholesterol Education Program Adult Treatment Panel 111 (NCEP ATP III; Am J Cardio 2003, 92: 19i-26i). Accordingly, therapeutic intervention strategies designed to impact these plasma lipid components as well as those that underlie insulin resistance are of great interest to the medical community. In terms of LDL-lowering, drugs of the statin class are structurally similar to the molecule hydroxymethylglutaryl-coenzyme A (HMG-CoA), a biosynthetic precursor of cholesterol. These drugs are competitive inhibitors of the rate-limiting step of cholesterol biosynthesis catalyzed by HMG-CoA reductase. Mechanistically, the statins lower LDL by upregulating the LDL receptor in the liver as well as by reducing the release of LDL into the circulation. As a monotherapy, the statin class of lipid lowering agents can reduce plasma LDL concentrations by 30-60% and triglycerides by 25%, producing a reduction in the incidence of CAD by 25-60% and the risk of death by 30%. Statins do not have an appreciable effect on HDL. A mechanistically distinct agent, Ezetimibe (Zetia, Merck and Co.), also possesses the ability to reduce plasma LDL, however it functions by inhibiting the absorption of cholesterol by the small intestine via antagonism of the NPC1L1 receptor (PNAS 2005, 102: 8132-8137). Monotherapy with Ezetimibe typically lowers LDL by 20%, however when co-formulated with a statin, maximal reductions can exceed 60%. As with the statins, however, Ezetimibe has a negligible effect on plasma HDL. While statins can have a modest impact on circulating triglycerides, PPAR alpha agonists (or fibrates) are far superior in targeting this lipid endpoint. The fibrates function by increasing lipolysis and elimination of triglyceride-rich particles from plasma by activating lipoprotein lipase and reducing production of apolipoprotein C-III (an inhibitor of lipoprotein lipase activity). One such fibrate, Fenofibrate (Tricor, Abott), has been shown in clinical studies to decrease plasma triglyceride levels upwards of 40-60%. Interestingly, the fibrate class of lipid-lowering drugs also has a modest, but significant effect on both LDL (20% reduction) and HDL (10% increase). Currently, the statin class of LDL lowering agents remains the cornerstone of dyslipidemia therapy. Despite the substantial reduction in cardiovascular events that have been achieved with this therapeutic approach, however, the cardio-protection that is afforded to patients by these therapies is still incomplete. It is now clear that therapies that are targeted to increase HDL cholesterol are critical in terms of maximizing patient cardio-protection. The only therapy available to date that has the ability to effectively raise circulating levels of cardio-protective HDL and consequently improve the progression of atherosclerosis in CAD patients is nicotinic acid (niacin or vitamin B3). Nicotinic acid was first reported to modify lipoprotein profiles in 1955 (Altschul et al. Arch Biochem Biophys 1955, 54: 558-559). Its effects are the most broad-spectrum of any available therapy, effectively raising HDL levels (20-30%) as well as lowering circulating plasma LDL (16%) and triglycerides (38%). The clinical significance of this broad-spectrum activity has been revealed in multiple large clinical studies. In the most recent ARBITER 2 (Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol 2; Taylor et al. Circulation 2004, 110: 3512-3517) study, patients on statin therapy were randomized to either placebo or 1000 mg extended release (ER) niacin (Niaspan, Kos Pharmaceuticals). Patients receiving niacin exhibited a statistically significant decrease in carotid intima-media thickness, a validated surrogate cardiovascular end point. This study also revealed a significantly reduced rate of intima-media thickness progression in subjects without detectable insulin resistance. This study indicates the incomplete cardio-protection that is offered by statin therapy and substantiates the utility of nicotinic acid in reducing overall cardiac risk in low-HDL patients. While nicotinic acid has been used clinically to modify lipid profiles for over four decades, the mechanism of action of the compound has remained largely obscure. It has long been known that acute nicotinic acid dosing results in a profound decrease in circulating free fatty acids (FFAs). This anti-lipolytic activity was first hypothesized in 1980 to be mediated by a membrane receptor linked to a decrease in intracellular cAMP (cyclic AMP, or cyclic adenosine monophosphate, or 3′-5′-cyclic adenosine monophosphate) levels (Aktories et al. FEBS Letters 1980, 115: 11-14). This hypothesis was later confirmed and the implied Gi/o GPCR-coupling was verified using pertussis toxin sensitivity studies (Aktories et al. FEBS Letters 1983, 156: 88-92). The identification of specific nicotinic acid binding sites on the surface of adipose and spleen cells confirmed the membrane hypothesis and refined, using modern-day techniques, the G-protein coupling of the receptor itself (Lorenzen et al. Mol Pharm 2001, 59: 349-357). This G-protein mediated, anti-lipolytic activity of nicotinic acid was used for two decades to identify and characterize nicotinic acid analogues in terms of their therapeutic potential. Finally, in 2003, two independent groups simultaneously published the cloning of an orphan Gi/o-coupled GPCR, HM74a (Wise et al. J Biol Chem 2003, 278: 9869-9874; Tunaru et al. Nat Med 2003, 9: 352-355), which binds to nicotinic acid with high affinity. As predicted, this receptor was shown to be expressed in adipose tissue and spleen, and binds to not only nicotinic acid, but also to the structurally related derivatives that had been previously shown to exhibit adipocyte anti-lipolytic activity. Mice that have been made deficient in the rodent ortholog of HM74a (Puma-g) by homologous recombination resist nicotinic acid-dependent FFA reduction and TG lowering. It is currently hypothesized that the nicotinic acid anti-lipolytic activity is based on the activation of this high affinity GPCR (HM74a), resulting in a decrease in intracellular cAMP and a subsequent attenuation of hormone sensitive lipase (HSL) activity. Decreased adipocyte lipolytic output results in a reduction in circulating FFA and a corresponding reduction in hepatic TGs, very-low density LDL (VLDL), and LDL. The increased levels of HDL arise from an effective reduction of cholesterol ester transfer protein activity due to decreased availability of VLDL acceptor molecules. Beyond impacting lipid levels and lipoprotein profiles, FFAs play fundamental roles in the regulation of glycemic control. It is now recognized that chronically elevated plasma FFA concentrations cause insulin resistance in muscle and liver, and impair insulin secretion (reviewed in Defronzo et al. Int. J. Clin. Prac. 2004, 58: 9-21). In muscle, acute elevations in plasma FFA concentrations can increase intramyocellular lipid content; this can have direct negative effects on insulin receptor signaling and glucose transport. In liver, increased plasma FFAs lead to accelerated lipid oxidation and acetyl-CoA accumulation, the later of which stimulates the rate-limiting steps for hepatic glucose production. In the pancreas, long-term exposure to elevated FFAs has been shown to impair the beta-cell's ability to secrete insulin in response to glucose. This data has driven the hypothesis that adipose tissue FFA release is a primary driver of the underlying pathologies in type 2 diabetes, and strategies designed to reduce FFAs, for example by agonizing HM74A, may prove effective in improving insulin sensitivity and lowering blood glucose levels in patients with type 2 diabetics/metabolic syndrome The utility of nicotinic acid as a hypolipidemic/FFA lowering agent is currently limited by four main factors. First, significant doses of nicotinic acid are required to impact FFA release and improve lipid parameters. Immediate release (IR) nicotinic acid is often dosed at 3-9 g/day in order to achieve efficacy, and ER nicotinic acid (Niaspan) is typically dosed between 1-2 g/day. These high doses drive the second issue with nicotinic acid therapy, hepatotoxicity. One of the main metabolic routes for nicotinic acid is the formation of nicotinamide (NAM). Increased levels of NAM have been associated with elevated liver transaminase which can lead to hepatic dysfunction. This toxicity is particularly problematic for sustained release formulations and results in the need to monitor liver enzymes during the initiation of therapy. Third, high doses of nicotinic acid are associated with severe prostaglandin-mediated cutaneous flushing. Virtually all patients experience flushing when on IR-nicotinic acid at or near the Tmax of the drug and discontinuation of therapy occurs in 20-50% of individuals. Niaspan, while exhibiting an increased dissolution time, still possesses a flushing frequency of approximately 70%, and this is in spite of the recommended dosing regimen that includes taking Niaspan along with an aspirin after a low-fat snack. Fourth, nicotinic acid therapy often results in FFA rebound, a condition whereby free fatty acid levels are not adequately suppressed throughout the dosing regimen, resulting in a compensatory increase in adipose tissue lipolysis. With immediate release nicotinic acid therapy, this rebound phenomenon is so great that daily FFA AUCs are actually increased after therapy. Such FFA excursions can lead to impaired glycemic control and elevated blood glucose levels, both of which have been shown to occur in some individuals after nicotinic acid therapy. Giving the importance of nicotinic acid in modulating (especially agonizing) HM74a receptor and its limitations, novel small molecules designed to mimic the mechanism of nicotinic acid's action on HM74a offer the possibility of achieving greater HDL, LDL, TG, and FFA efficacy while avoiding adverse effects such as hepatotoxicity and cutaneous flushing. Such therapies are envisoned to have significant impact beyond dyslipidemia to include insulin resistance, hyperglycemia, and associated syndromes by virtue of their ability to more adequately reduce plasma FFA levels during the dosing interval. The present invention is directed to these, as well as other, important ends. SUMMARY OF THE INVENTION The present invention provides, inter alia, compounds of Formula I: or pharmaceutically acceptable salts or prodrugs thereof, wherein constituent members are defined herein. The present invention further provides compositions comprising a compound of the invention and at least one pharmaceutically acceptable carrier. The present invention further provides methods of modulating HM74a receptor with a compound of the invention. The present invention further provides methods of agonizing HM74a receptor by contacting the HM74a receptor with a compound of the invention. The present invention further provides methods of treating diseases associated with HM74a receptor. The present invention further provides a compound of the invention for use in therapy. The present invention further provides a compound of the invention for use in the preparation of a medicament for use in therapy. DETAILED DESCRIPTION The present invention provides, inter alia, compounds which are agonists or partial agonists of HM74a and are useful in the treatment of a variety of diseases, such as cardiovascular diseases. The compounds can have Formula I: or pharmaceutically acceptable salt or prodrug thereof, wherein: a dashed line indicates an optional bond; X is N, CR3a, CR4aR5a or NR6a; Y is N, CR3b, CR4bR5b, or NR6b; L is —(C1-6 alkylene)-(Q1)m-(C1-6 alkylene)p-(Q2)q-(C1-6 alkylene)r-, optionally substituted with 1, 2, 3, 4, or 5 RL1, wherein if m and q are both 1, then p is 1; R1 is H, C1-10alkyl, C2-10alkenyl, C2-10alkynyl, or Cy, wherein said C1-10alkyl, C2-10alkenyl, or C2-10alkynyl is optionally substituted with 1, 2, 3, 4, or 5 RL2; R2 is halo, cyano, C1-3 haloalkyl, Z, SRA, or a moiety having the formula: R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, or C2-6 alkynyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd; R4a, R4b, R5a, and R5b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa, S(O)Rb1, S(O)NRc1Rd1S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; R6a and R6b are independently selected from H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, Cy2, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy2, CN, NO2, ORa1, SRa1, C(O)Rb1, C(O)NRc1Rd1, C(O)ORa1, OC(O)Rb1, OC(O)NRc1Rd1, NRc1Rd1, NRc1C(O)Rb1, NRc1C(O)NRc1Rd1, NRc1C(O)ORa1, S(O)Rb1, S(O)NRc1Rd1, S(O)2Rb1, NRc1S(O)2Rb1, and S(O)2NRc1Rd1; RL1 and RL2 are independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, CN, NO2, ORa2, SRa2, C(O)Rb2, C(O)NRc2Rd2, C(O)ORa2, OC(O)Rb2, OC(O)NRc2Rd2, NRc2Rd2, NRc2C(O)Rc2, NRc2C(O)NRc2Rd2, NRc2C(O)ORa2, S(O)Rb2, S(O)NRc2Rd2, S(O)2Rb2, NRc2S(O)2Rb2, and S(O)2NRc2Rd2; R2a is H, C1-6 alkyl, C2-6 alkenyl, C2-10alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy4, CN, NO2, C(O)Rb6, C(O)NRc6Rd6, or C(O)ORa6; Cy is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa3, SRa3, C(O)Rb3, C(O)NRc3Rd3, C(O)ORa3, OC(O)Rb3, OC(O)NRc3Rd3, NRc3Rd3, NRc3C(O)Rb3, NRc3C(O)ORa3, S(O)Rb3, S(O)NRc3Rd3, S(O)2Rb3, and S(O)2NRc3Rd3; Cy1 and Cy2 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)b4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, or C2-4 alkynyl is optionally substituted with 1, 2, or 3 substituents independently selected from CN, NO2, halo, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3; Cy3 and Cy4 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa6, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; Z is aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa, SRa, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6; RA is H or C1-4 alkyl; Q1 and Q2 are independently selected from O, S, NH, CH2, CO, CS, SO, SO2, OCH2, SCH2, NHCH2, CH2CH2, COCH2, CONH, COO, SOCH2, SONH, SO2CH2, and SO2NH; Ra and Ra1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Ra2, Ra3, Ra4, Ra5, and Ra6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rb and Rb1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rb2, Rb3, Rb4, Rb5, and Rb6 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, cycloalkyl, heteroaryl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, cyano, amino, halo, C1-6 alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; Rc and Rd are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc and Rd together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc1 and Rd1 are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, and Cy2, wherein said C1-6 alkyl, C1-6 haloalkyl, C2-6 alkenyl, or C2-6 alkynyl, is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)R5b, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; or Rc1 and Rd1 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group optionally substituted with 1, 2, or 3 substituents independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy2, CN, NO2, ORa5, SRa5, C(O)Rb5, C(O)NRc5Rd5, C(O)ORa5, OC(O)Rb5, OC(O)NRc5Rd5, NRc5Rd5, NRc5C(O)Rb5, NRc5C(O)NRc5Rd5, NRc5C(O)ORa5, S(O)Rb5, S(O)NRc5Rd5, S(O)2Rb5, NRc5S(O)2Rb5, and S(O)2NRc5Rd5; Rc2 and Rd2 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc2 and Rd2 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc3 and Rd3 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc3 and Rd3 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc4 and Rd4 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc4 and Rd4 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; Rc5 and Rd5 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc5 and Rd5 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and Rc6 and Rd6 are independently selected from H, C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl, and heterocycloalkylalkyl, wherein said C1-10 alkyl, C1-6 haloalkyl, C2-6 alkenyl, C2-6 alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, cycloalkylalkyl or heterocycloalkylalkyl is optionally substituted with OH, amino, halo, C1-6 alkyl, C1-6 haloalkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl, cycloalkyl or heterocycloalkyl; or Rc6 and Rd6 together with the N atom to which they are attached form a 4-, 5-, 6- or 7-membered heterocycloalkyl group; and m, p, q, and r are independently selected from 0 and 1. In some embodiments, when XY is CR4aR5a—CR4bR5b, then R2 is other than halo, C1-3 haloalkyl, Z or SRA. In some embodiments, when XY is CR3a═N, then R2 is other than Z; In some embodiments, when XY is N═CR3b and R3b is H or unsubstituted aryl, then R2 is other than unsubstituted aryl; In some embodiments, when XY is N═N, then R2 is other than aryl; and In some embodiments, when XY is CR3a═CR3b, then -L-R1 is other than methyl. In some embodiments, when X is CR4aR5a and Y is CR4bR5b, then R2 is other than halo or C1 trihaloalkyl. In some embodiments, when X is CR4aR5a and Y is CR4bR5b, then R2 is other than Br or C3 trihaloalkyl. In some embodiments, XY is other than CR4aR5a—CR4bR5b In some embodiments, R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, C1-6 cyanoalkyl, Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, or C2-6 alkynyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd. In some embodiments, Cy1 and Cy2 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, or C2-4 alkynyl is optionally substituted with 1, 2, or 3 substituents independently selected from CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)b4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3. In some embodiments, X is N. In some embodiments, X is CR3a In some embodiments, X is CR4aR5a. In some embodiments, X is CH. In some embodiments, Y is N. In some embodiments, Y is N3b. In some embodiments, Y is CR. In some embodiments, Y is CH. In some embodiments, Y is C-Me. In some embodiments, Y is CR4bR5b. In some embodiments, X is N and Y is CR3b. In some embodiments, X is CR3a and Y is N. In some embodiments, X is CH and Y is N. In some embodiments, X and Y are both N. In some embodiments, at least one of X and Y is N. In some embodiments, R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd. In some embodiments, R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd), NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd. In some embodiments, R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, and NRcC(O)Rb. In some embodiments, R3a and R3b are independently selected from H, C1-6 alkyl, C1-6 haloalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, halo, ORa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb. In some embodiments: at least one of R3a and R3b is selected from Cy1; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. In some embodiments, at least one of R3a and R3b is selected from C1-6 alkyl and C1-6 haloalkyl, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from C(O)NRcRd, C(O)ORa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb. In some embodiments: at least one of R3a and R3b is selected from C1-3 alkyl, wherein said C1-3 alkyl is substituted with Cy1 and optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa6, SRa6, C(O)Rb6, C(O)NRc6Rd6, C(O)ORa6, OC(O)Rb6, OC(O)NRc6Rd6, NRc6Rd6, NRc6C(O)Rb6, NRc6C(O)ORa6, S(O)Rb6, S(O)NRc6Rd6, S(O)2Rb6, and S(O)2NRc6Rd6. In some embodiments: at least one of R3a and R3b is selected from C1-3 alkyl, wherein said C1-3 alkyl is substituted with Cy1 and optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. In some embodiments: at least one of R3a and R3b is selected from C1-3 alkyl, wherein said C1-3 alkyl is substituted with Cy1 and optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each substituted with 1 or 2 R7 and optionally substituted by 1, 2, or 3 R8; R7 is, at each occurrence, independently selected from Cy3 and C1-4 alkyl, wherein said C1-4 alkyl is substituted with 1 or 2 Cy3 and optionally substituted with 1 or 2 substituents independently selected from halo and ORa4; R8 is, at each occurrence, independently selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, and C(O)ORa4; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. In some embodiments, at least one of R3a and R3b is -LA-Cy1, wherein LA is C1-3 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa. In some further embodiments, Cy1 is aryl or heteroaryl, each optionally substituted by 1, 2, or 3 substituents independently selected from Cy3, halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, and C(O)ORa4. In yet further embodiments, Cy1 is 1,2,4-oxadiazolyl optionally substituted by 1, 2, or 3 substituents independently selected from Cy3, halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, and C(O)ORa4. In some embodiments, one of R3a and R3b is -LA-Cy1, and the other is selected from H, C1-4 alkyl, and C1-4 haloalkyl. In some embodiments, at least one of R3a and R3b is -LA-Cy1-(LB)t1-Cy3, wherein LA is C1-3 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; LB is C1-4 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo and ORa4; and t1 is 0 or 1. In some further embodiments, LA is C1-3 alkylene optionally substituted with OH. In yet embodiments, LA is C2-3 alkylene optionally substituted with OH. In further embodiments, LA is C2-3 alkylene. In some embodiments, t1 is 0. In some embodiments, t1 is 1. In some embodiments, LB is C1-4 alkylene optionally substituted with OH. In some further embodiments, LB is C1-3 alkylene optionally substituted with OH. In some embodiments, at least one of R3a and R3b is -LA-Cy1-(LB)t1-Cy3, wherein LA is C1-3 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo and ORa. In some further embodiments, LA is C1-3 alkylene optionally substituted with halo or OH. In some embodiments, at least one of R3a and R3b is -LA-Cy1-(LB)t1-Cy3, wherein LB is C1-4 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo and ORa4. In some further embodiments, LB is C1-4 alkylene optionally substituted with halo or OH. In some embodiments, at least one of R3a and R3b is -LA-Cy1-(LB)t1-Cy3; and Cy1 is aryl or heteroaryl, each optionally substituted by 1, 2, or 3 substituents independently selected from Cy3, halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, and C(O)ORa4. In some further embodiments, Cy1 is 1,2,4-oxadiazolyl. In some embodiments, Cy3 is selected from aryl and heteroaryl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, NRc6Rd6, and ORa6. In some further embodiments, Cy3 is selected from aryl and heteroaryl, each substituted by OH and optionally substituted with 1, 2, or 3 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, NRc6Rd6, and ORa6. In some embodiments, one of R3a and R3b is -LA-Cy1-(LB)t1-Cy3, and the other is selected from H, C1-4 alkyl, and C1-4 haloalkyl. In some embodiments, R3a and R3b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, and C1-6 haloalkyl. In some embodiments, R3a and R3b are independently selected from H, halo, and C1-6 alkyl. In some embodiments, R3a and R3b are independently selected from H and C1-4 alkyl. In some further embodiments, R3a and R3b are independently selected from H and methyl. In yet further embodiments, R3a or R3b is methyl. In some embodiments, one of R3a and R3b is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl. In some embodiments, R3a and R3b are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl. In some embodiments, R3b is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. In some embodiments, R3b is heteroaryl that is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from aryl, cycloalkyl, and heterocycloalkyl, each optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa6, and SRa6. In some embodiments, R3b is thiazolyl that is optionally substituted with phenyl, wherein said phenyl is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from OH and halo. In some embodiments, m and q are both 0. In some embodiments, m is 0. In some embodiments, q is 0. In some embodiments, m is 1. In some embodiments, q is 1. In some embodiments, p is 1. In some embodiments, r is 1. In some embodiments, p is 0. In some embodiments, r is 0. In some embodiments, L is —(C1-18 alkylene)- optionally substituted by 1, 2, 3, 4, or 5 RL1. In some further embodiments, each RL1 is independent selected from halo, OH, and CN. In yet further embodiments, each RL1 is independent halo. In some embodiments, L is C1-6 alkylene optionally substituted by 1, 2, 3, 4, or 5 RL1. In some further embodiments, each RL1 is independent selected from halo, OH, and CN. In yet further embodiments, each RL1 is independent halo. In some embodiments, L is —(C1-18 alkylene)-. In some further embodiments, L is C1-6 alkylene. In some embodiments, R1 is H, C1-10alkyl, or Cy, wherein said C1-10 alkyl is optionally substituted with 1, 2, 3, 4, or 5 RL2. In some embodiments, R1 is H, C1-10 alkyl optionally substituted with 1, 2, 3, 4, or 5 RL2. In some embodiments, R1 is H or C1-3 alkyl, wherein said C1-3 alkyl is optionally substituted with 1, 2, 3, 4, or 5 RL2. In some further embodiments, RL2 is, at each occurrence, independently selected from halo, CN, NO2, and ORa2. In yet further embodiments, each RL2 is independent halo. In some embodiments, R1 is H or C1-10alkyl. In some embodiments, R1 is Cy. In some embodiments, -L-R1 is C1-10 alkyl. In some embodiments, -L-R1 is C1-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some embodiments, -L-R1 is C3-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some embodiments, -L-R1 is C2-6 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some embodiments, -L-R1 is C2-6 alkyl. In some embodiments, -L-R1 is C3-7 alkyl. In some embodiments, -L-R1 is C4-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some embodiments, -L-R1 is butyl or pentyl. In some embodiments, R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: In some embodiments, R2 is halo, cyano, C1 haloalkyl, Z, or, SRA. In some embodiments, R2 is halo, cyano, C1 haloalkyl, or a moiety having the formula: In some embodiments, R2 is halo, cyano, or C1-3 haloalkyl. In some embodiments, R2 is halo or C 3 haloalkyl. In some embodiments, R2 is Cl, Br, or CF3. In some embodiments, R2 is C1-3 haloalkyl. In some further embodiments, R2 is CF3 or CF2CF3—In yet further embodiments, R2 is CF3. In some other embodiments, R2 is CF2CF3. In some embodiments, R2 is C1 haloalkyl. In some embodiments, R2 is halo. In some further embodiments, R2 is Cl or Br. In some embodiments, R2 is Br. In some embodiments, R2 is Cl. In some embodiments, R2 is CF3. In some embodiments, R2 is a moiety having the formula: In some embodiments, R2 is S-Me. In some embodiments, R2 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, and ORa4. In some embodiments, R2a is H (i.e., R2 is acetylenyl). In some embodiments, R4a, R4b, R5a, and R5b are independently selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, and C1-6 cyanoalkyl. In some embodiments, RL1 and RL2 are independently selected from halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, CN, NO2, and ORa2. In some embodiments, Cy is aryl optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa3, SRa3, C(O)Rb3, C(O)NRc3Rd3, C(O)ORa3, OC(O)Rb3, OC(O)NRc3Rd3, NRc3Rd3, NRc3C(O)Rb3, NRc3C(O)ORa3, S(O)Rb3, S(O)NRc3Rd3, S(O)2Rb3, and S(O)2NRc3Rd3. In some embodiments, Cy is aryl. In some embodiments, Cy is heteroaryl optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa3, SRa3, C(O)Rb3, C(O)NRc3Rd3, C(O)ORa3, OC(O)Rb3, OC(O)NRc3Rd3, NRc3Rd3, NRc3C(O)b3, NRc3C(O)ORa3, S(O)Rb3, S(O)NRc3Rd3, S(O)2Rb3, and S(O)2NRc3Rd3. In some embodiments, Cy is heteroaryl. In some embodiments, Cy is cycloalkyl optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa3, SRa3, C(O)Rb3, C(O)NRc3Rd3, C(O)ORa3, OC(O)Rb3, OC(O)NRc3Rd3, NRc3Rd3, NRc3C(O)Rb3, NRc3C(O)ORa3, S(O)Rb3, S(O)NRc3Rd3, S(O)2Rb3, and S(O)2NRc3Rd3. In some embodiments, Cy is cycloalkyl. In some embodiments, Cy is heterocycloalkyl optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa3, SRa3, C(O)Rb3, C(O)NRc3Rd3, C(O)ORa3, OC(O)Rb3, OC(O)NRc3Rd3, NRc3Rd3, NRc3C(O)Rb3, NRc3C(O)ORa3, S(O)Rb3, S(O)NRc3Rd3, S(O)2Rb3, and S(O)2NRc3Rd3. In some embodiments, Cy is heterocycloalkyl. In some embodiments, Cy1 and Cy2 are independently selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)Rb4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, and S(O)2NRc4Rd4. In some embodiments, Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)b4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted by 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3. In some embodiments, Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, OC(O)b4, OC(O)NRc4Rd4, NRc4Rd4, NRc4C(O)Rb4, NRc4C(O)ORa4, S(O)Rb4, S(O)NRc4Rd4, S(O)2Rb4, S(O)2NRc4Rd4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted by 1, 2, or 3 substituents independently selected from ORa4 and Cy3. In some embodiments, Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3. In some embodiments, Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from ORa4 and Cy3. In some embodiments, Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, OR6, and SRa6. In some embodiments, Cy3 is selected from aryl or heteroaryl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, OH, —O—(C1-4 alkyl) and —O—(C1-4 haloalkyl). In some embodiments, Cy3 is selected from aryl or heteroaryl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, NH2, —NH(C1-4 alkyl), —N(C1-4 alkyl)2, OH, —O—(C1-4 alkyl) and —O—(C1-4 haloalkyl). In some embodiments, the compounds of the invention have Formula II: wherein constituent members are provided herein. In some embodiments, the compounds of the invention have Formula II, wherein -L-R1 is C1-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C2-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl. In some further embodiments, -L-R1 is butyl or pentyl. In some embodiments, the compounds of the invention have Formula II, wherein R2 is halo. In some further embodiments, R2 is Cl or Br. In yet further embodiments, R2 is Br. In other further embodiments, R2 is Cl. In some embodiments, the compounds of the invention have Formula II, wherein R3b is selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRdS(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd. In some embodiments, the compounds of the invention have Formula II, wherein R3b is selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd. In some embodiments, the compounds of the invention have Formula II, wherein R3b is selected from H, C1-6 alkyl, C1-6 haloalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, halo, ORa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb. In some further embodiments, R3b is C1-3 alkyl. In yet further embodiments, R3b is methyl. In some embodiments, the compounds of the invention have Formula II, wherein: R3b is Cy1; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, ORa, SRa4, C(O)Ra4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. In some embodiments, the compounds of the invention have Formula II, wherein R3b is C1-6 alkyl or C1-6 haloalkyl, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from C(O)NRcRd, C(O)ORa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb. In some embodiments, the compounds of the invention have Formula II, wherein: R3b is selected from C1-3 alkyl, wherein said C1-3 alkyl is substituted with Cy1 and optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each substituted with 1 or 2 R7 and optionally substituted by 1, 2, or 3 R8; R7 is, at each occurrence, independently selected from Cy3 and C1-4 alkyl, wherein said C1-4 alkyl is substituted with 1 or 2 Cy3 and optionally substituted with 1 or 2 substituents independently selected from halo and ORa4; R8 is, at each occurrence, independently selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, and C(O)ORa4; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. In some embodiments, the compounds of the invention have Formula II, wherein: L is C1-6 alkylene; R1 is H or C1-3 alkyl, wherein said C1-3 alkyl is optionally substituted with 1, 2, 3, 4, or 5 RL2; and RL2 is, at each occurrence, independently selected from halo, CN, NO2, and ORa2. In some embodiments, the compounds of the invention have Formula II, wherein R2 is halo or C1-3 haloalkyl. In some embodiments, the compounds of the invention have Formula II, wherein R2 is Br. In some embodiments, the compounds of the invention have Formula II, wherein: L is C1-18alkylene; R3b is H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, or NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd; and R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: In some embodiments, the compounds of the invention have Formula II, wherein: L is C1-18 alkylene; R3b is H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, or NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd; and R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: In some embodiments, the compounds of the invention have Formula II, wherein: L is C1-18alkylene; R3b is H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, or NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, halo, ORa, C(O)NRcRd, C(O)ORa, and NRcC(O)Rb; and R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: In some embodiments, the compounds of the invention have Formula II, wherein: L is C1-18alkylene; R3b is heteroaryl that is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from aryl, cycloalkyl, and heterocycloalkyl, wherein said aryl, cycloalkyl, or heterocycloalkyl is optionally substituted by 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, CN, NO2, ORa6, SRa6, and R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: In some embodiments, the compounds of the invention have Formula II, wherein: L is C1-18 alkylene; R3b is thiazolyl that is optionally substituted with phenyl, wherein said phenyl is optionally substituted with 1, 2, 3, 4, or 5 substituents independently selected from OH and halo and R2 is halo, cyano, C1 haloalkyl, Z, SRA, or a moiety having the formula: In some embodiments, the compounds of the invention have Formula II, wherein: L is C1-18 alkylene; R3b is H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, or C1-6 haloalkyl; and R2 is halo, cyano, or C1 haloalkyl. In some embodiments, the compounds of the invention have Formula II, wherein: R3b is C1-6 alkyl, C1-6 haloalkyl, or Cy1, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, halo, ORa, SRa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb; L is C1-6 alkylene optionally substituted with 1, 2, 3, 4, or 5 RL1; R1 is H or C1-3 alkyl, wherein said C1-3 alkyl is optionally substituted with 1, 2, 3, 4, or 5 RL2; RL1 and RL2 are, at each occurrence, independently selected from halo, CN, NO2, and ORa2; and R2 is halo or C1-3 haloalkyl. In some embodiments, the compounds of the invention have Formula II, wherein -L-R1 is C1-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo; and R2 is halo. In some further embodiments, -L-R1 is C2-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, R2 is Br or Cl. In further embodiments, R2 is Br. In some embodiments, the compounds of the invention have Formula II, wherein -L-R1 is C3-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo; and R2 is halo. In some further embodiments, -L-R1 is C4-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In yet further embodiments, -L-R1 is butyl or pentyl. In some embodiments, the novel compounds of Formula II have Formula Ia: wherein LA is C1-3 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; and wherein Cy1, L, R1, and R2 are defined as the same as hereinabove. In some embodiments, the compounds of the invention have Formula Ia, wherein -L-R1 is C1-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C2-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl. In some embodiments, the compounds of the invention have Formula Ia, wherein -L-R1 is C3-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C4-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In yet embodiments, -L-R1 is butyl or pentyl. In some embodiments, the compounds of the invention have Formula Ia, wherein R2 is halo or C1-3 haloalkyl. In some further embodiments, R2 is halo. In yet further embodiments, R2 is Br. In some embodiments, the compounds of the invention have Formula Ia, wherein Cy1 is optionally substituted 1,2,4-oxadiazolyl. In some embodiments, the 1,2,4-oxadiazolyl of Cy1 is optionally substituted by 1, 2, or 3 substituents independently selected from Cy3, halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, and C(O)ORa4. In some embodiments, the novel compounds of Formula II have Formula IIb: wherein: LA is C1-3 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; LB is C1-4 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo and ORa4; t1 is 0 or 1; and Cy1, Cy3, L, R1, and R2 are defined as the same as hereinabove. In some embodiments, the compounds of the invention have Formula IIb, wherein -L-R1 is C1-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C2-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl. In some embodiments, the compounds of the invention have Formula IIb, wherein -L-R1 is C3-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C4-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In yet embodiments, -L-R1 is butyl or pentyl. In some embodiments, the compounds of the invention have Formula IIb, wherein R2 is halo or C1-3 haloalkyl. In some further embodiments, R2 is halo. In some further embodiments, R2 is Cl or Br. In yet further embodiments, R2 is Br. In some embodiments, the compounds of the invention have Formula IIb, wherein Cy1 is 1,2,4-oxadiazolyl. In some embodiments, the compounds of the invention have Formula IIb, wherein LA is C1-3 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo and OH. In some further embodiments, LA is C2-3 alkylene optionally substituted with OH. In yet further embodiments, LA is C2-3 alkylene. In some embodiments, the compounds of the invention have Formula IIb, wherein LA is C1-3 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo and OH. In some further embodiments, LA is C2-3 alkylene optionally substituted with 1 or 2 halo. In yet further embodiments, LA is C2-3 alkylene optionally substituted with halo. In some embodiments, the compounds of the invention have Formula IIb, wherein t1 is 0. In some embodiments, the compounds of the invention have Formula IIb, wherein t1 is 1. In some embodiments, the compounds of the invention have Formula IIb, wherein t1 is 0. In some embodiments, the compounds of the invention have Formula IIb, wherein LB is C1-4 alkylene optionally substituted with 1 or 2 substitutents independently selected from halo and OH. In some further embodiments, LB is C1-3 alkylene optionally substituted with OH. In some embodiments, the compounds of the invention have Formula IIb, wherein LB is C1-4 alkylene optionally substituted with 1 or 2 halo. In some further embodiments, LB is C1-3 alkylene optionally substituted with halo. In some further embodiments, LB is C1-3 alkylene. In some embodiments, the compounds of the invention have Formula IIb, wherein Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, NRc6Rd6 and ORa6. In some embodiments, the compounds of the invention have Formula IIb, wherein Cy3 is selected from aryl and heteroaryl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, NRc6Rd6, and ORa6. In some further embodiments, Cy3 is selected from aryl and heteroaryl, each substituted by OH and optionally substituted with 1, 2, or 3 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, NRc6Rd6, and ORa6. In some embodiments, the compounds of the invention have Formula III: wherein constituent members are provided herein. In some further embodiments, R2 is halo or C1-3 haloalkyl. In yet further embodiments, R2 is halo. In still further embodiments, R2 is Br. In some embodiments, the compounds of the invention have Formula III, wherein R2 is halo. In some further embodiments, R2 is Cl or Br. In yet further embodiments, R2 is Br. In other further embodiments, R2 is Cl. In some embodiments, the compounds of the invention have Formula III, wherein -L-R1 is C1-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C2-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl. In some embodiments, the compounds of the invention have Formula III, wherein -L-R1 is C3-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C4-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In yet embodiments, -L-R1 is butyl or pentyl. In some embodiments, the compounds of the invention have Formula IV: wherein constituent members are provided herein. In some further embodiments, R2 is halo or C1-3 haloalkyl. In yet further embodiments, R2 is halo. In still further embodiments, R2 is Br or Cl. In further embodiments, R2 is Br. In other further embodiments, R2 is Cl. In some embodiments, the compounds of the invention have Formula IV, wherein -L-R1 is C1-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C2-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C3-6 alkyl. In some embodiments, the compounds of the invention have Formula IV, wherein -L-R1 is C3-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In some further embodiments, -L-R1 is C4-7 alkyl optionally substituted with 1, 2, 3, 4 or 5 halo. In yet embodiments, -L-R1 is butyl or pentyl. In some embodiments, the compounds of the invention have Formula IV, wherein R3a is selected from H, halo, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C1-6 haloalkyl, C1-6 hydroxyalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl are optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, CN, NO2, halo, ORa, SRa, C(O)Rb, C(O)NRcRd, C(O)ORa, OC(O)Rb, OC(O)NRcRd, NRcRd, NRcC(O)Rb, NRcC(O)NRcRd, NRcC(O)ORa, S(O)Rb, S(O)NRcRd, S(O)2Rb, NRcS(O)2Rb, and S(O)2NRcRd. In some embodiments, the compounds of the invention have Formula IV, wherein R3a is selected from H, C1-6 alkyl, C1-6 haloalkyl, Cy1, ORa, SRa, S(O)Rb, S(O)2Rb, and NRcRd, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from Cy1, C(O)NRcRd, C(O)ORa, halo, ORa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb. In some further embodiments, R3a is selected from H and C1-6 alkyl. In yet further embodiments, R3a is selected from H and methyl. In some embodiments, the compounds of the invention have Formula IV, wherein: R3a is Cy1; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, C(O)ORa4, and Cy3, wherein said C1-4 alkyl, C2-4 alkenyl, and C2-4 alkynyl are optionally substituted with 1, 2, or 3 substituents independently selected from halo, ORa4 and Cy3; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. In some embodiments, the compounds of the invention have Formula IV, wherein R3a is C1-6 alkyl or C1-6 haloalkyl, wherein said C1-6 alkyl is optionally substituted with 1, 2, or 3 substitutents independently selected from C(O)NRcRd, C(O)ORa, NRcRd, NRcC(O)NRcRd, and NRcC(O)Rb. In some embodiments, the compounds of the invention have Formula IV, wherein R3a: R3a is selected from C1-3 alkyl, wherein said C1-3 alkyl is substituted with Cy1 and optionally substituted with 1 or 2 substitutents independently selected from halo, ORa, and SRa; Cy1 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each substituted with 1 or 2 R7 and optionally substituted by 1, 2, or 3 R8; R7 is, at each occurrence, independently selected from Cy3 and C1-4 alkyl, wherein said C1-4 alkyl is substituted with 1 or 2 Cy3 and optionally substituted with 1 or 2 substitutents independently selected from halo and ORa4; R8 is, at each occurrence, independently selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, CN, NO2, ORa4, SRa4, C(O)Rb4, C(O)NRc4Rd4, and C(O)ORa4; and Cy3 is selected from aryl, heteroaryl, cycloalkyl, and heterocycloalkyl, each optionally substituted with 1, 2, 3, 4 or 5 substituents selected from halo, C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 haloalkyl, aryl, heteroaryl, CN, NO2, NRc6Rd6, ORa6, and SRa6. At various places in the present specification, substituents of compounds of the invention are disclosed in groups or in ranges. It is specifically intended that the invention include each and every individual subcombination of the members of such groups and ranges. For example, the term “C1-6 alkyl” is specifically intended to individually disclose methyl, ethyl, C3 alkyl (e.g., n-propyl or isopropyl), C4 alkyl (e.g., n-butyl, isobutyl, t-butyl), or, C5 alkyl (e.g., n-pentyl, isopentyl, or neopentyl), and C6 alkyl. For compounds of the invention in which a variable appears more than once, each variable can be a different moiety selected from the Markush group defining the variable. For example, where a structure is described having two R groups that are simultaneously present on the same compound; the two R groups can represent different moieties selected from the Markush group defined for R. In another example, when an optionally multiple substituent is designated in the form: then it is understood that substituent R can occur s number of times on the ring, and R can be a different moiety at each occurrence. Further, in the above example, should the variable T be defined to include hydrogens, such as when T is said to be CH2, NH, etc., any floating substituent such as R in the above example, can replace a hydrogen of the T variable as well as a hydrogen in any other non-variable component of the ring. It is further intended that the compounds of the invention are stable. As used herein “stable” refers to a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and preferably capable of formulation into an efficacious therapeutic agent. It is further appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable subcombination. For compounds of the invention in which a variable appears more than once, each variable can be a different moiety selected from the Markush group defining the variable. For example, where a structure is described having two R groups that are simultaneously present on the same compound; the two R groups can represent different moieties selected from the Markush group defined for R. As used herein, the term “alkyl” is meant to refer to a saturated hydrocarbon group which is straight-chained or branched. Example alkyl groups include methyl (Me), ethyl (Et), propyl (e.g., n-propyl and isopropyl), butyl (e.g., n-butyl, isobutyl, t-butyl), pentyl (e.g., n-pentyl, isopentyl, neopentyl), and the like. An alkyl group can contain from 1 to about 20, from 2 to about 20, from 1 to about 10, from 1 to about 8, from 1 to about 6, from 1 to about 4, or from 1 to about 3 carbon atoms. As used herein, the term “alkylene” refers to a linking alkyl group. One example of alkylene is CH2CH2—. As used herein, “alkenyl” refers to an alkyl group having one or more double carbon-carbon bonds. Example alkenyl groups include ethenyl, propenyl, and the like. As used herein, “alkynyl” refers to an alkyl group having one or more triple carbon-carbon bonds. Example alkynyl groups include ethynyl, propynyl, and the like. As used herein, “haloalkyl” refers to an alkyl group having one or more halogen substituents. Example haloalkyl groups include CH2F, CHF2, CF3, C2F5, CCl3, CHCl2, CH2CF3, C2Cl5, and the like. As used herein, “aryl” refers to monocyclic or polycyclic (e.g., having 2, 3 or 4 fused rings) aromatic hydrocarbons such as, for example, phenyl, naphthyl, anthracenyl, phenanthrenyl, and the like. In some embodiments, aryl groups have from 6 to about 20 carbon atoms. As used herein, “cycloalkyl” refers to non-aromatic carbocycles including cyclized alkyl, alkenyl, and alkynyl groups. Cycloalkyl groups can include mono- or polycyclic (e.g., having 2, 3 or 4 fused rings) ring systems, including spirocycles. In some embodiments, cycloalkyl groups can have from 3 to about 20 carbon atoms, 3 to about 14 carbon atoms, 3 to about 10 carbon atoms, or 3 to 7 carbon atoms. Cycloalkyl groups can further have 0, 1, 2, or 3 double bonds and/or 0, 1, or 2 triple bonds. Also included in the definition of cycloalkyl are moieties that have one or more aromatic rings fused (i.e., having a bond in common with) to the cycloalkyl ring, for example, benzo derivatives of pentane, pentene, hexane, and the like. A cycloalkyl group having one or more fused aromatic rings can be attached though either the aromatic or non-aromatic portion. One or more ring-forming carbon atoms of a cycloalkyl group can be oxidized, for example, having an oxo or sulfido substituent. Example cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopentenyl, cyclohexenyl, cyclohexadienyl, cycloheptatrienyl, norbornyl, norpinyl, norcamyl, adamantyl, and the like. As used herein, a “heteroaryl” group refers to an aromatic heterocycle having at least one heteroatom ring member such as sulfur, oxygen, or nitrogen. Heteroaryl groups include monocyclic and polycyclic (e.g., having 2, 3 or 4 fused rings) systems. Any ring-forming N atom in a heteroaryl group can also be oxidized to form an N-oxo moiety. Examples of heteroaryl groups include without limitation, pyridyl, N-oxopyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, furyl, quinolyl, isoquinolyl, thienyl, imidazolyl, thiazolyl, indolyl, pyrryl, oxazolyl, benzofuryl, benzothienyl, benzothiazolyl, isoxazolyl, pyrazolyl, triazolyl, tetrazolyl, indazolyl, 1,2,4-thiadiazolyl, isothiazolyl, benzothienyl, purinyl, carbazolyl, benzimidazolyl, indolinyl, and the like. In some embodiments, the heteroaryl group has from 1 to about 20 carbon atoms, and in further embodiments from about 3 to about 20 carbon atoms. In some embodiments, the heteroaryl group contains 3 to about 14, 3 to about 7, or 5 to 6 ring-forming atoms. In some embodiments, the heteroaryl group has 1 to about 4, 1 to about 3, or 1 to 2 heteroatoms. As used herein, “heterocycloalkyl” refers to a non-aromatic heterocycle where one or more of the ring-forming atoms is a heteroatom such as an O, N, or S atom. Heterocycloalkyl groups can include mono- or polycyclic (e.g., having 2, 3 or 4 fused rings) ring systems as well as spirocycles. Example “heterocycloalkyl” groups include morpholino, thiomorpholino, piperazinyl, tetrahydrofuranyl, tetrahydrothienyl, 2,3-dihydrobenzofuryl, 1,3-benzodioxole, benzo-1,4-dioxane, piperidinyl, pyrrolidinyl, isoxazolidinyl, isothiazolidinyl, pyrazolidinyl, oxazolidinyl, thiazolidinyl, imidazolidinyl, and the like. Also included in the definition of heterocycloalkyl are moieties that have one or more aromatic rings fused (i.e., having a bond in common with) to the nonaromatic heterocyclic ring, for example phthalimidyl, naphthalimidyl, and benzo derivatives of heterocycles. A heterocycloalkyl group having one or more fused aromatic rings can be attached though either the aromatic or non-aromatic portion. In some embodiments, the heterocycloalkyl group has from 1 to about 20 carbon atoms, and in further embodiments from about 3 to about 20 carbon atoms. In some embodiments, the heterocycloalkyl group contains 3 to about 20, 3 to about 14, 3 to about 7, or 5 to 6 ring-forming atoms. In some embodiments, the heterocycloalkyl group has 1 to about 4, 1 to about 3, or 1 to 2 heteroatoms. In some embodiments, the heterocycloalkyl group contains 0 to 3 double bonds. In some embodiments, the heterocycloalkyl group contains 0 to 2 triple bonds. As used herein, “arylalkyl” refers to alkyl substituted by aryl and “cycloalkylalkyl” refers to alkyl substituted by cycloalkyl. One example of arylalkyl is benzyl. One example of cycloalkylalkyl is —CH2CH2-cyclopropyl. As used herein, “heteroarylalkyl” refers to an alkyl group substituted by a heteroaryl group, and “heterocycloalkylalkyl” refers to alkyl substituted by heterocycloalkyl. One example of heteroarylalkyl is —CH2— (pyridin-4-yl). One example of heterocycloalkylalkyl is —CH2-(piperidin-3-yl). As used herein, “halo” or “halogen” includes fluoro, chloro, bromo, and iodo. As used herein, “hydroxyalkyl” refers to an alkyl group substituted with a hydroxyl group. As used herein, “cyanoalkyl” refers to an alkyl group substituted with a cyano group. The compounds described herein can be asymmetric (e.g., having one or more stereocenters). All stereoisomers, such as enantiomers and diastereomers, are intended unless otherwise indicated. Compounds of the present invention that contain asymmetrically substituted carbon atoms can be isolated in optically active or racemic forms. Methods on how to prepare optically active forms from optically active starting materials are known in the art, such as by resolution of racemic mixtures or by stereoselective synthesis. Many geometric isomers of olefins, C═N double bonds, and the like can also be present in the compounds described herein, and all such stable isomers are contemplated in the present invention. Cis and trans geometric isomers of the compounds of the present invention are described and may be isolated as a mixture of isomers or as separated isomeric forms. Compounds of the invention also include tautomeric forms. Tautomeric forms result from the swapping of a single bond with an adjacent double bond together with the concomitant migration of a proton. Tautomeric forms include prototropic tautomers which are isomeric protonation states having the same empirical formula and total charge. Example prototropic tautomers include ketone-enol pairs, amide-imidic acid pairs, lactam-lactim pairs, amide-imidic acid pairs, enamine-imine pairs, and annular forms where a proton can occupy two or more positions of a heterocyclic system, for example, 1H- and 3H-imidazole, 1H-, 2H- and 4H-1,2,4-triazole, 1H- and 2H-isoindole, and 1H- and 2H-pyrazole. Tautomeric forms can be in equilibrium or sterically locked into one form by appropriate substitution. Compounds of the invention can also include all isotopes of atoms occurring in the intermediates or final compounds. Isotopes include those atoms having the same atomic number but different mass numbers. For example, isotopes of hydrogen include tritium and deuterium. The term, “compound,” as used herein is meant to include all stereoisomers, geometric iosomers, tautomers, and isotopes of the structures depicted. All compounds, and pharmaceutically acceptable salts thereof, are also meant to include solvated or hydrated forms. In some embodiments, the compounds of the invention, and salts thereof, are substantially isolated. By “substantially isolated” is meant that the compound is at least partially or substantially separated from the environment in which it was formed or detected. Partial separation can include, for example, a composition enriched in the compound of the invention. Substantial separation can include compositions containing at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 97%, or at least about 99% by weight of the compound of the invention, or salt thereof. Methods for isolating compounds and their salts are routine in the art. The present invention also includes pharmaceutically acceptable salts of the compounds described herein. As used herein, “pharmaceutically acceptable salts” refers to derivatives of the disclosed compounds wherein the parent compound is modified by converting an existing acid or base moiety to its salt form. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. The pharmaceutically acceptable salts of the present invention include the conventional non-toxic salts of the parent compound formed, for example, from non-toxic inorganic or organic acids. The pharmaceutically acceptable salts of the present invention can be synthesized from the parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418 and Journal of Pharmaceutical Science, 66, 2 (1977), each of which is incorporated herein by reference in its entirety. The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. The present invention also includes prodrugs of the compounds described herein. As used herein, “prodrugs” refer to any covalently bonded carriers which release the active parent drug when administered to a mammalian subject. Prodrugs can be prepared by modifying functional groups present in the compounds in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent compounds. Prodrugs include compounds wherein hydroxyl, amino, sulfhydryl, or carboxyl groups are bonded to any group that, when administered to a mammalian subject, cleaves to form a free hydroxyl, amino, sulfhydryl, or carboxyl group respectively. Examples of prodrugs include, but are not limited to, acetate, formate and benzoate derivatives of alcohol and amine functional groups in the compounds of the invention. Preparation and use of prodrugs is discussed in T. Higuchi and V. Stella, “Pro-drugs as Novel Delivery Systems,” Vol. 14 of the A.C.S. Symposium Series, and in Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987, both of which are hereby incorporated by reference in their entirety. Synthesis The compounds of the present invention can be prepared in a variety of ways known to one skilled in the art of organic synthesis. The compounds of the present invention can be synthesized using the methods as hereinafter described below, together with synthetic methods known in the art of synthetic organic chemistry or variations thereon as appreciated by those skilled in the art. The compounds of this invention can be prepared from readily available starting materials using the following general methods and procedures. It will be appreciated that where typical or preferred process conditions (i.e., reaction temperatures, times, mole ratios of reactants, solvents, pressures, etc.) are given; other process conditions can also be used unless otherwise stated. Optimum reaction conditions may vary with the particular reactants or solvent used, but such conditions can be determined by one skilled in the art by routine optimization procedures. The processes described herein can be monitored according to any suitable method known in the art. For example, product formation can be monitored by spectroscopic means, such as nuclear magnetic resonance spectroscopy (e.g., 1H or 13C) infrared spectroscopy, spectrophotometry (e.g., UV-visible), or mass spectrometry, or by chromatography such as high performance liquid chromatography (HPLC) or thin layer chromatography. Preparation of Compounds can Involve the Protection and Deprotection of Various Chemical groups. The need for protection and deprotection, and the selection of appropriate protecting groups can be readily determined by one skilled in the art. The chemistry of protecting groups can be found, for example, in Greene, et al., Protective Groups in Organic Synthesis, 2d. Ed., Wiley & Sons, 1991, which is incorporated herein by reference in its entirety. The reactions of the processes described herein can be carried out in suitable solvents which can be readily selected by one of skill in the art of organic synthesis. Suitable solvents can be substantially nonreactive with the starting materials (reactants), the intermediates, or products at the temperatures at which the reactions are carried out, i.e., temperatures which can range from the solvent's freezing temperature to the solvent's boiling temperature. A given reaction can be carried out in one solvent or a mixture of more than one solvent. Depending on the particular reaction step, suitable solvents for a particular reaction step can be selected. The compounds of the invention can be prepared, for example, using the reaction pathways and techniques as described below. Compounds of formula 1i and 1j can be prepared using the generally protocol described in Scheme 1. Intermediates 1c can be synthesized by reaction of thiourea 1a with a cyanoacetic acid ester such as ethyl cyanoacetate 1b in the present of a base such as sodium ethoxide to generate cyclic intermediates 1c. Nitrosation of intermediate 1c using sodium nitrite gives rise to the nitroso intermediate 1d, which can be reduced to the diamino intermediate 1e using Na2S2O4 or a similar reducing agent. Cyclization of the diamino intermediate 1e with trifluoroacetic anhydride yields the thioxopurinone intermediate 1f. Following selective methylation on the sulfur of compound 1f, the resulting thioether intermediate 1g is subjected to a displacement with hydrazine to produce the hydrazone intermediate 1h. Treatment of the hydrazone intermediate 1h with an orthoester [such as R3bC(O-alkyl)3, e.g., R3bC(OEt)3] yields the cyclized triazole compounds of formula 1i. Alternatively, intermediate 1h can be treated with NaNO2 to provide a cyclized tetrazole compound of formula 1j. Compounds of formula 2g and 2i can be prepared using the procedures outlined in Scheme 2. Selective alkylation at the amino group of commercially available 3-amino-1H-pyrrole-2-carboxamide (2a) by reductive amination with an aldehyde R1L1-CHO [wherein L1-CH2 has the same definition as that of L defined hereinwith] provides the alkylated product 2b. Reaction of intermediate 2b with benzoyl isothiocyanate yields the thiourea intermediate 2c, which can be treated with a base such as aqueous NaOH to provide the cyclized thioxopurinone intermediate 2d. Treatment of intermediate 2d with aqueous hydrazine produces the hydrazone derivative 2e. Cyclization of the hydrazone intermediate 2e can be achieved by treatment with an orthoester [such as R3bC(O-alkyl)3, e.g., R3bC(OEt)3] to yield the triazole derivative 2f Selective halogenation at the 7-position of 2f can be carried out using a halogenating reagent, for example, N-bromosuccinimide (NBS) or N-chlorosuccinimide (NCS) to provide the halo-substituted triazolopurinone derivative of formula 2g. Alternatively, the tetrazolopurinone derivatives of formula 2i can be obtained by cyclization of the intermediate 2e using NaNO2 under acidic condition [such as in the presence of aqueous HCl] followed by halogenation using a halogenating reagent, for example, NBS or NCS. Compounds of formula 3d can be prepared using the protocol outlined in Scheme 3. Reaction of hydrazone derivative 2e with an appropriate aldehyde R3bCHO in a suitable solvent such as an alcohol (e.g. ethanol) yields intermediate 3b. Oxidative cyclization of 3b in acetic acid (in air) provides the corresponding triazolopurine 3c. Alternatively, triazolopurine 3c can be prepared by cyclization (and condensation) of the intermediate 3f, which is derived from the amide bond formation by coupling of hydrazone 2e with acid 3e, in a suitable solvent such as acetic acid or in toluene. Selective halogenation at the 7-position of the triazolopurinone core of 3c using a halogenation reagent, for example NBS or NCS, provides the halo-substituted triazolopurinone derivative of formula 3d. Compounds of formula 4f and 4j [wherein R7 can be aryl, heteroaryl, arylakyl, heteroarylalkyl, and the like] can be prepared using the procedures described in Scheme 4. Oxidative cyclization of hydrazone 4b, which is generated from treatment of hydrazone 2e with an aldehyde 4a in a suitable solvent such as ethanol, provides the intermediate acid 4c. Reaction of acid 4c with amine 4d under amide formation condition [such as in the presence of an amide coupling reagent, for example, benzotriazolyloy-tris-(dimethylamino)phosphonium hexafluorophosphate (or BOP)] produces amide 4e, which can be treated with a halogenating reagent such as NBS or NCS to provide a halo-substituted triazolopurinone amide derivative of formula 4f. Oxadiazol intermediate 41 can be prepared by coupling of acid 4c with N-hydroxy imidamide 4g using a coupling reagent such as 1,1′-carbonyldiimidazole (CDI), followed by cyclization (and condensation). Alternatively, coupling of oxadiazol acid 4h with hydrazone 2e under suitable conditions (such as in the presence of an amid coupling reagent, for example BOP), followed by cyclization (and condensation), can also yield oxadiazole 41. Selective halogenation at the 7-position of the triazolopurinone core of compound 41, using a halogenating reagent such as NBS or NCS, provides the halo-substituted triazolopurinone oxadiazol derivative of formula 4j. Compounds of formula 5b can be synthesized using the general procedures outlined in Scheme 5. Reaction of halide 3d with a boric acid 5a (such as those commercially available or disclosed in the literatures, wherein Z is optionally substituted aryl or optionally substituted heteroaryl) under Suzuki coupling conditions can yield triazolopurinone derivatives of formula 5b. An alternative general synthetic pathway for 5b starts with intermediate 1e. Reaction of intermediate 1e with acid 5c (wherein Z can be optionally substituted aryl, heteroaryl, cycloalkyl, or heterocycloalkyl) under amide coupling conditions (such as in the presence of an amid coupling reagent, for example BOP) provides amide 5d, which can be treated with a base such as aqueous NaOH to give thioxopurinone intermediate 5e. Treatment of intermediate 5e with aqueous hydrazine produces the hydrazone derivative 5f. Reaction of dyazone 5f with an orthoester [such as R3bC(O-alkyl)3, e.g., R3bC(OEt)3] yields triazolopurinone derivative 5b. Alternatively, halide 3d can be reacted with an alkyne 5g under Sonogashira coupling condition to afford an allyne derivative 5h. (See, e Sonogashira, K. et al. Tetrahedron Letter, 1975, 4467; see also, Nicolaou, K. C. Et al. Angew. Chem. Int. Engl. 1991, 30, 1100) Scheme 6 exemplifies the preparation of 3-substituted triazolopurinone derivatives such as those having formula 6d, 6g or 6j. Treatment of hydrazone 2e with N-(dichloromethylene)-N-methylmethananaminium chloride provide 6c, which can be treated with a halogenated reagent such as NBS or NCS to yield halo-substituted amino triazolopurinone derivative 6d. Reaction of 2e with carbon disulfide in a suitable solvent such as pyridine produces cyclic thiourea 6e. Alkylation of thiourea 6e on the sulfur atom using an appropriate alkylating agent such as dimethyl sulfate or ethyl iodide under basic condition (such as in the presence of aqueous NaOH), followed by oxidation of the resultant thioether in the presence of an oxidizing reagent such as m-chloroperbenzoic acid, affords sulfinyl intermediate 6f, which can be treated with a halogenating reagent such as NBS or NCS to provide halo-substituted sulfinyl-triazolopurinone derivative 6g. Sulfinyl intermediate 6f (or its precursor thioether) can be further oxidized to its corresponding sulfonyl counterpart, which in turn can further undergo selective halogenation. Treatment of hydrazone 2e with CDI give intermediates 6h. Alkylation of intermediate 6h on the hydroxyl group (such as using alkyl halide RaX1 wherein X1 is bromo), followed by halogenation with a halogenating reagent such as NBS or NCS, provides triazolopurinone derivatives of formula 6j. Compounds of formula 4j can be also prepared using the procedures described in Scheme 7. Reaction of hydrazone 2e with cyclic anhydride 7a (wherein n can be 1, 2 or 3) under suitable conditions (such as refluxing in dioxane) furnishes triazolopurinone acid derivative 7b. Selective halogenation at the 7-position of the triazolopurinone core of compound 7b using a halogenating reagent such as NBS or NCS provides the halo-substituted triazolopurinone derivative 7c. Coupling of acid 7c with N-hydroxy imidamide 4g [wherein R7 can be aryl, heteroaryl, arylakyl, heteroarylalkyl, and the like] using a coupling reagent such as CDI, followed by cyclization (and condensation), yields halo-substituted triazolopurinone oxadiazol derivative 4j. Compounds of formula 8f (wherein ring A1 is a heterocylic ring that has at least one nitrogen atom as ring-forming atom and that is substituted by R7 and optionally substituted by one or more R8 wherein R7 can be aryl, heteroaryl, arylakyl, heteroarylalkyl, and the like; R8 can be alkyl, haloalkyl, alkoxy and the like; and t can be 0, 1, 2 or 3) can be prepared using the protocol outlined in Scheme 8. Reacting of an NH-containing heterocycle 8a (which is substituted by R7 and optionally substituted by 1, 2 or 3 R8) with halo-substituted ester 8b (wherein n can be 1, or 2) in the presence of a base such as K2CO3 gives ester 8c. Hydrolysis of ester 8c under basic conditions (such as using sodium hydroxide in water-methanol) provides acid 8d. Coupling of acid 8d with hydrazone 2e, followed by cyclization (and condensation), affords trazolopurinone derivative 8e, which is subjected to selective halogenation to yield the halo-substituted trazolopurinone derivative formula 8f. Compounds of formula 9h can be prepared using the general procedures described in Scheme 9. Addition of hydroxylamine to commercially available 4,4-diethoxybutanenitrile 9a (wherein n can be 1, or 2) in methanol provide imidamide 9b. Coupling of imidamide 9b with acid 9c (wherein R7 can be aryl, heteroaryl, arylakyl, heteroarylalkyl, and the like) in the presence of a coupling reagent such as CDI, followed by cyclization (and condensation), affords oxadiazole derivative 9d, which can undergo acid catalyzed ketal deprotection to furnish oxadiazole aldehyde 9e. Reaction of aldehyde 9e with hydrazone derivative 2e in a suitable solvent such as ethanol provides intermediate 9f. Oxidative cyclization of 9f (such as in acetic acid and in the presence of air) provides the corresponding triazolopurine 9g, which can be treated with a halogenating reagent NBS or NCS to yield halo-substituted triazolopurinone oxadiazol derivative 9h. Compounds of formula 10e, 10f or 10g can be prepared using the protocol described in Scheme 10. Amide coupling of protected amino acid 10a [wherein P1 is an amine protecting group such as tert-butyloxycarbonyl (or Boc) or benzyloxycarbonyl (or Cbz); and n can be 1, or 2] with hydrazone 2e gives intermediate amide 10b. Cyclization of 10b under suitable conditions such as refluxing in acetic acid or refluxing in toluene, followed by deprotection of the amino group (that has the protecting group P1), provides amino-substituted triazolopurinone derivative 10c. Selective halogenation at the 7-position of the triazolopurinone core of compound 10c using a halogenating reagent, for example, NBS or NCS provides intermediate 10d. Amide coupling of intermediate 10d with acid Rb—COOH (wherein Rb can be, for example, aryl, heteroaryl, arylakyl, heteroarylalkyl, and the like) yields halo-substituted triazolopurinone amide derivative 10e. Triazolopurinone urea derivative 10f can be obtained by reacting intermediate 10d with an isocyanate Rd—N═C═O or its equivalent [such as a carbamate, for example Rd—NH—(C═O)—O-alkyl (e.g., Rd—NH—(C═O)—O-methyl) or Rd—NH—(C═O)—O-phenyl]. Reaction of intermediate 10d with Rd—X2 wherein X2 is a leaving group such as halide [Rd—X can be aryl halide or heteroaryl halide] under base-facilitated nucleophilic replacement condition or palladium catalyzed arylamination condition provides halo-substituted triazolopurinone derivatives of formula 10g. Pharmaceutical Methods Compounds of the invention can modulate activity of the HM74a receptor. The term “modulate” is meant to refer to an ability to increase or decrease activity of a receptor. Accordingly, compounds of the invention can be used in methods of modulating HM74a receptor by contacting the receptor with any one or more of the compounds or compositions described herein. In some embodiments, compounds of the present invention can act as full or partial agonists of HM74a receptors. In further embodiments, the compounds of the invention can be used to modulate activity of HM74a receptors in an individual by administering a modulating amount of a compound of the invention. The present invention further provides methods of treating diseases associated with the HM74a receptor, such as dyslipidemia, insulin resistance, hyperglycemia, and others, in an individual (e.g., patient) by administering to the individual in need of such treatment a therapeutically effective amount or dose of a compound of the present invention or a pharmaceutical composition thereof. Example diseases can include any disease, disorder or condition that is directly or indirectly linked to the HM74a receptor, such as diseases, disorders or conditions associated with low expression or low activity of HM74a receptor. Examples of HM74a receptor-associated diseases include, but are not limited to, dyslipidemia, highly-active anti-retroviral therapy (HAART)-associated lipodystrophy, insulin resistance, diabetes such as type 2 diabetes mellitus, metabolic syndrome, atherosclerosis, coronary heart disease, stroke, obesity, elevated body mass index (BMI), elevated waist circumference, non-alcoholic fatty liver disease, hepatic steatosis, hypertension, and other pathologies, such as those (like many of the aforementioned) associated with elevated plasma FFAs. Other diseases treatable by administration of compounds of the invention (and salts or prodrugs there) include chronic inflammatory diseases such as, for example, pancreatitis and gout. As used herein, the term “dyslipidemia” refers to any one or more of the following diseases or conditions: low-HDL cholesterol, elevated cholesterol, elevated LDL cholesterol (including any combination of small, dense LDL, intermediate density lipoproteins, very-low density lipoproteins, and chylomicrons), elevated total cholesterol/HDL ratio, elevated plasma triglycerides, elevated circulating free fatty acid levels, and elevated lipoprotein (a). In some embodiments, the present invention provides methods of lowering cholesterol level, lowering LDL, lowering total cholesterol/HDL ratio, lowering plasma triglycerides, lowering circulating free fatty acid levels, lowering lipoprotein (a), or raising HDL cholesterol, in a mammal by administering an effective amount of a compound or composition herein to the mammal. As used herein, the term “cell” is meant to refer to a cell that is in vitro, ex vivo or in vivo. In some embodiments, an ex vivo cell can be part of a tissue sample excised from an organism such as a mammal. In some embodiments, an in vitro cell can be a cell in a cell culture. In some embodiments, an in vivo cell is a cell living in an organism such as a mammal. In some embodiments, the cell is an adipocyte, a pancreatic cell, a hepatocyte, neuron, or cell comprising the eye. As used herein, the term “contacting” refers to the bringing together of indicated moieties in an in vitro system or an in vivo system. For example, “contacting” the HM74a receptor with a compound of the invention includes the administration of a compound of the present invention to an individual or patient, such as a human, having the HM74a receptor, as well as, for example, introducing a compound of the invention into a sample containing a cellular or purified preparation containing the HM74a receptor. As used herein, the term “individual” or “patient,” used interchangeably, refers to any animal, including mammals, preferably mice, rats, other rodents, rabbits, dogs, cats, swine, cattle, sheep, horses, or primates, and most preferably humans. As used herein, the phrase “therapeutically effective amount” refers to the amount of active compound or pharmaceutical agent that elicits the biological or medicinal response that is being sought in a tissue, system, animal, individual or human by a researcher, veterinarian, medical doctor or other clinician. As used herein, the term “treating” or “treatment” refers to one or more of (1) preventing the disease; for example, preventing a disease, condition or disorder in an individual who may be predisposed to the disease, condition or disorder but does not yet experience or display the pathology or symptomotology of the disease; (2) inhibiting the disease; for example, inhibiting a disease, condition or disorder in an individual who is experiencing or displaying the pathology or symptomotology of the disease, condition or disorder; and (3) ameliorating the disease; for example, ameliorating a disease, condition or disorder in an individual who is experiencing or displaying the pathology or symptomotology of the disease, condition or disorder (i.e., reversing or retarding the pathology and/or symptomotology) such as decreasing the severity of disease. Combination Therapies The compounds of the present invention can be used in combination with other enzyme or receptor modulators. Examples of other enzyme or receptor modulators include, but are not limited to, any one or more of the following: steroidal and non-steroidal anti-inflammatory agents (e.g., inhibitors or prostaglandin synthesis), inhibitors of PCSK9, inhibitors of ACC1, inhibitors of ACC2, inhibitors of SCD1, inhibitors of DGAT, activators of AMPK, thyroid receptor modulators, renin inhibitors, agents that degrade or inhibit formation of advanced glycation end products, HMG-CoA reductase inhibitors (so-called statins), PPAR alpha agonists or selective modulators, PPAR gamma agonists or selective modulators (both TZD and non-TZD), PPAR delta agonists or selective modulators, PPAR alpha/gamma dual agonists, pan-PPAR agonists or selective modulators, glucocorticoid receptor antagonists or selective modulators, bile acid-binding resins, NPC1L1 receptor antagonists, cholesterol ester transfer protein inhibitors, apoA-I or synthetic apoA-I/HDL molecules, LXR agonists or selective modulators, FXR agonists or selective modulators, endothelial lipase inhibitors, hepatic lipase inhibitors, SR-BI modulators, estrogen receptor agonists or selective modulators, anabolic steroid or steroid derivatives, insulin or insulin mimetics, sulfonylureas, metformin or other biguanides, DPP-IV inhibitors, PTP-1B modulators, glucose-6-phosphatase inhibitors, T1-translocase inhibitors, fructose-1,6-bisphosphatase inhibitors, glycogen phosphorylase inhibitors, glucagon receptor antagonists, 11-beta-hydroxysteroid dehydrogenase type 1 inhibitors, intestinal lipase inhibitors, neurotransmitter reuptake inhibitor, endocannabinoid receptor antagonist, NPY antagonist, MCH antagonists, MC4R agonists, GLP-1 or GLP-1 analogues (incretins), GLP-1 receptor agonists, thiazide diuretics, beta-adrenergic receptor antagonists, angiotensin II converting enzyme inhibitors, angiotensin II receptor antagonists, calcium channel antagonists, and mineralocorticoid receptor antagonists, or combinations thereof. Pharmaceutical Formulations and Dosage Forms When employed as pharmaceuticals, the compounds of the invention can be administered in the form of pharmaceutical compositions. These compositions can be prepared in a manner well known in the pharmaceutical art, and can be administered by a variety of routes, depending upon whether local or systemic treatment is desired and upon the area to be treated. Administration may be topical (including ophthalmic and to mucous membranes including intranasal, vaginal and rectal delivery), pulmonary (e.g., by inhalation or insufflation of powders or aerosols, including by nebulizer; intratracheal, intranasal, epidermal and transdermal), ocular, oral or parenteral. Methods for ocular delivery can include topical administration (eye drops), subconjunctival, periocular or intravitreal injection or introduction by balloon catheter or ophthalmic inserts surgically placed in the conjunctival sac. Parenteral administration includes intravenous, intraarterial, subcutaneous, intraperitoneal or intramuscular injection or infusion; or intracranial, e.g., intrathecal or intraventricular, administration. Parenteral administration can be in the form of a single bolus dose, or may be, for example, by a continuous perfusion pump. Pharmaceutical compositions and formulations for topical administration may include transdermal patches, ointments, lotions, creams, gels, drops, suppositories, sprays, liquids and powders. Conventional pharmaceutical carriers, aqueous, powder or oily bases, thickeners and the like may be necessary or desirable. This invention also includes pharmaceutical compositions which contain, as the active ingredient, one or more of the compounds of the invention above in combination with one or more pharmaceutically acceptable carriers. In making the compositions of the invention, the active ingredient is typically mixed with an excipient, diluted by an excipient or enclosed within such a carrier in the form of, for example, a capsule, sachet, paper, or other container. When the excipient serves as a diluent, it can be a solid, semi-solid, or liquid material, which acts as a vehicle, carrier or medium for the active ingredient. Thus, the compositions can be in the form of tablets, pills, powders, lozenges, sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, aerosols (as a solid or in a liquid medium), ointments containing, for example, up to 10% by weight of the active compound, soft and hard gelatin capsules, suppositories, sterile injectable solutions, and sterile packaged powders. In preparing a formulation, the active compound can be milled to provide the appropriate particle size prior to combining with the other ingredients. If the active compound is substantially insoluble, it can be milled to a particle size of less than 200 mesh. If the active compound is substantially water soluble, the particle size can be adjusted by milling to provide a substantially uniform distribution in the formulation, e.g. about 40 mesh. The compounds of the invention may be milled using known milling procedures such as wet milling to obtain a particle size appropriate for tablet formation and for other formulation types. Finely divided (nanoparticulate) preparations of the compounds of the invention can be prepared by processes known in the art, for example see International Patent Application No. WO 2002/000196. Some examples of suitable excipients include lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates, tragacanth, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, and methyl cellulose. The formulations can additionally include: lubricating agents such as talc, magnesium stearate, and mineral oil; wetting agents; emulsifying and suspending agents; preserving agents such as methyl- and propylhydroxy-benzoates; sweetening agents; and flavoring agents. The compositions of the invention can be formulated so as to provide quick, sustained or delayed release of the active ingredient after administration to the patient by employing procedures known in the art. The compositions can be formulated in a unit dosage form, each dosage containing from about 5 to about 100 mg, more usually about 10 to about 30 mg, of the active ingredient. The term “unit dosage forms” refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical excipient. The active compound can be effective over a wide dosage range and is generally administered in a pharmaceutically effective amount. It will be understood, however, that the amount of the compound actually administered will usually be determined by a physician, according to the relevant circumstances, including the condition to be treated, the chosen route of administration, the actual compound administered, the age, weight, and response of the individual patient, the severity of the patient's symptoms, and the like. For preparing solid compositions such as tablets, the principal active ingredient is mixed with a pharmaceutical excipient to form a solid preformulation composition containing a homogeneous mixture of a compound of the present invention. When referring to these preformulation compositions as homogeneous, the active ingredient is typically dispersed evenly throughout the composition so that the composition can be readily subdivided into equally effective unit dosage forms such as tablets, pills and capsules. This solid preformulation is then subdivided into unit dosage forms of the type described above containing from, for example, 0.1 to about 500 mg of the active ingredient of the present invention. The tablets or pills of the present invention can be coated or otherwise compounded to provide a dosage form affording the advantage of prolonged action. For example, the tablet or pill can comprise an inner dosage and an outer dosage component, the latter being in the form of an envelope over the former. The two components can be separated by an enteric layer which serves to resist disintegration in the stomach and permit the inner component to pass intact into the duodenum or to be delayed in release. A variety of materials can be used for such enteric layers or coatings, such materials including a number of polymeric acids and mixtures of polymeric acids with such materials as shellac, cetyl alcohol, and cellulose acetate. The liquid forms in which the compounds and compositions of the present invention can be incorporated for administration orally or by injection include aqueous solutions, suitably flavored syrups, aqueous or oil suspensions, and flavored emulsions with edible oils such as cottonseed oil, sesame oil, coconut oil, or peanut oil, as well as elixirs and similar pharmaceutical vehicles. Compositions for inhalation or insufflation include solutions and suspensions in pharmaceutically acceptable, aqueous or organic solvents, or mixtures thereof, and powders. The liquid or solid compositions may contain suitable pharmaceutically acceptable excipients as described supra. In some embodiments, the compositions are administered by the oral or nasal respiratory route for local or systemic effect. Compositions in can be nebulized by use of inert gases. Nebulized solutions may be breathed directly from the nebulizing device or the nebulizing device can be attached to a face masks tent, or intermittent positive pressure breathing machine. Solution, suspension, or powder compositions can be administered orally or nasally from devices which deliver the formulation in an appropriate manner. The amount of compound or composition administered to a patient will vary depending upon what is being administered, the purpose of the administration, such as prophylaxis or therapy, the state of the patient, the manner of administration, and the like. In therapeutic applications, compositions can be administered to a patient already suffering from a disease in an amount sufficient to cure or at least partially arrest the symptoms of the disease and its complications. Effective doses will depend on the disease condition being treated as well as by the judgment of the attending clinician depending upon factors such as the severity of the disease, the age, weight and general condition of the patient, and the like. The compositions administered to a patient can be in the form of pharmaceutical compositions described above. These compositions can be sterilized by conventional sterilization techniques, or may be sterile filtered. Aqueous solutions can be packaged for use as is, or lyophilized, the lyophilized preparation being combined with a sterile aqueous carrier prior to administration. The pH of the compound preparations typically will be between 3 and 11, more preferably from 5 to 9 and most preferably from 7 to 8. It will be understood that use of certain of the foregoing excipients, carriers, or stabilizers will result in the formation of pharmaceutical salts. The therapeutic dosage of the compounds of the present invention can vary according to, for example, the particular use for which the treatment is made, the manner of administration of the compound, the health and condition of the patient, and the judgment of the prescribing physician. The proportion or concentration of a compound of the invention in a pharmaceutical composition can vary depending upon a number of factors including dosage, chemical characteristics (e.g., hydrophobicity), and the route of administration. For example, the compounds of the invention can be provided in an aqueous physiological buffer solution containing about 0.1 to about 10% w/v of the compound for parenteral administration. Some typical dose ranges are from about 1 μg/kg to about 1 g/kg of body weight per day. In some embodiments, the dose range is from about 0.01 mg/kg to about 100 mg/kg of body weight per day. The dosage is likely to depend on such variables as the type and extent of progression of the disease or disorder, the overall health status of the particular patient, the relative biological efficacy of the compound selected, formulation of the excipient, and its route of administration. Effective doses can be extrapolated from dose-response curves derived from in vitro or animal model test systems. The compounds of the invention can also be formulated in combination with one or more additional active ingredients which can include any pharmaceutical agent such as anti-viral agents, antibodies, immune suppressants, anti-inflammatory agents and the like. Labeled Compounds and Assay Methods Another aspect of the present invention relates to fluorescent dye, spin lable, heavy metal or radio-labeled compounds of the invention that would be useful not only in imaging but also in assays, both in vitro and in vivo, for localizing and quantitating HM74a in tissue samples, including human, and for identifying HM74a ligands by binding of a labeled compound. Accordingly, the present invention includes HM74a assays that contain such labeled compounds. The present invention further includes isotopically-labeled compounds of the invention. An “isotopically” or “radio-labeled” compound is a compound of the invention where one or more atoms are replaced or substituted by an atom having an atomic mass or mass number different from the atomic mass or mass number typically found in nature (i.e., naturally occurring). Suitable radionuclides that may be incorporated in compounds of the present invention include but are not limited to 2H (also written as D for deuterium), 3H (also written as T for tritium), 13C, 13C, 14C, 13N, 15N, 15O, 17O, 18O, 18F, 35S, 36Cl, 82Br, 75Br, 76Br, 77Br, 123I, 124I, 125I and 131I. The radionuclide that is incorporated in the instant radio-labeled compounds will depend on the specific application of that radio-labeled compound. For example, for in vitro labeling and competition assays, compounds that incorporate 3H, 14C, 82Br, 125I, 131I, 35S or will generally be most useful. For radio-imaging applications 11C, 18F, 125I, 123I, 124I, 131I, 75Br, 76Br or 77Br will generally be most useful. It is understood that a “radio-labeled” or “labeled compound” is a compound that has incorporated at least one radionuclide. In some embodiments the radionuclide is selected from the group consisting of 3H, 14C, 125I, 35S and 82Br. Synthetic methods for incorporating radio-isotopes into organic compounds are applicable to compounds of the invention and are well known in the art. A radio-labeled compound of the invention can be used in a screening assay to identify/evaluate compounds. In general terms, a newly synthesized or identified compound (i.e., test compound) can be evaluated for its ability to reduce binding of the radio-labeled compound of the invention to HM74a. Accordingly, the ability of a test compound to compete with the radio-labeled compound for binding to HM74a directly correlates to its binding affinity. Kits The present invention also includes pharmaceutical kits useful, for example, in the treatment or prevention of HM74a-associated diseases or disorders. The kits can include one or more containers containing a pharmaceutical composition comprising a therapeutically effective amount of a compound of the invention. Such kits can further include, if desired, one or more of various conventional pharmaceutical kit components, such as, for example, containers with one or more pharmaceutically acceptable carriers, additional containers, etc., as will be readily apparent to those skilled in the art. Instructions, either as inserts or as labels, indicating quantities of the components to be administered, guidelines for administration, and/or guidelines for mixing the components, can also be included in the kit. The invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes, and are not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of noncritical parameters which can be changed or modified to yield essentially the same results. The compounds of the example section were found to be agonists or partial agonists of HM74a receptor according to one or more of the assays provided herein. EXAMPLES General Information All reagents and solvents were obtained from commercial sources and were used directly without further purification. LCMS analysis was performed on a Water SunFire C18 column ((2.1×50 mm, 5 μM particle size), eluting with 0.025% TFA/water and 0.025% TFA/acetonitrile using a mass spectrum scan range of 105-900 Da. Preparative LCMS purifications were performed on a Water FractionLynx system using mass directed fraction and compound-specific method optimization (J. Comb. Chem. 2004, 6, 874-883). The LC method utilized a Water SunFire column (19×100 mm, 5 μM particle size), eluting with either 0.1% TFA/water and 0.1% TFA/acetonitrile gradient at a flow rate of 30 mL/min. over a total run time of 5 min. NMR spectra were obtained using a Varian Mercury-300 or Mercury-400 spectrometer. Chemical shifts are reported in parts per million (ppm) relative to tetramethylsilane as an internal standard. Example 1 Preparation of 3-methyl-9-pentyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A N-Pentylthiourea Pentylisothiocyanate (10 g, 0.08 mol) was added slowly (about 10 mins) to a mixture of ammonia (50 mL, 0.2 mol) in methanol (7 N) at 0° C. After being stirred at room temperature for 1 h, the solvent was stripped off and the product was obtained as a white solid (10 g, 88.4%), which was used for next step without further purification. LCMS calculated for C6H15N2S: (M+H) 147.1; found 147.1. Step B 6-Amino-1-pentyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-one N-Pentylthiourea (10.0 g, 0.068 mol) was mixed with ethyl cyanoacetate (9.3 g, 0.082 mol) and sodium ethoxide (6.4 g, 0.094 mol) in ethanol (60 mL). The mixture was stirred at 75° C. overnight. After cooling, a solution of 10% acetic acid in water (150 mL) was added. The solid formed was collected by filtration and washed with water to afford the desired product (9.5 g, 65% yield). LCMS calculated for C9H16N3OS: (M+H) 214.1; found 214.1. Step C 6-Amino-5-nitroso-1-pentyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-one 6-Amino-1-pentyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-one (8.0 g, 0.038 mol) was mixed with sodium nitrite (3.1 g, 0.045 mol) in acetic acid (120 mL). The mixture was stirred at 75° C. for 1 h. The color of the reaction mixture became pink and then purple. The solution was allowed to cool down to room temperature, and water (40 mL) was added. The solid was collected by suction filtration and washed with water (50 mL) to produce the desired product, which was used directly for next step without further purification. LCMS calculated for C9H15N4O2S: (M+H) 243.1; found 243.1. Step D 5,6-Diamino-1-pentyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-one To a mixture of 6-amino-1-pentyl-5-nitroso-2-thioxo-2,3-dihydropyrimidin-4(1H)-one (6.4 g, 0.0264 mol), aqueous ammonia (60 mL, 0.60 mol) and water (60 mL) at 75° C. was added sodium dithionite (9.0 g, 0.050 mol) in small portions. After the addition was complete, the color of the solution changed from red to pale yellow. After stirring at 75° C. for another 5 mins, a precipitate was formed. Stirring was continued at room temperature for 1.5 h. The solution was then neutralized with 10% acetic acid (150 mL). The solid was filtered and washed with water to yield the product (4.5 g, 86.1%). LCMS calculated for C9H17N4OS: (M+H) 229.1; found 229.1. Step E 3-Pentyl-2-thioxo-8-(trifluoromethyl)-1,2,3,7-tetrahydro-6H-purin-6-one 5,6-Diamino-1-pentyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-one (2.0 g, 0.0088 mol) was mixed with trifluoroacetic anhydride (10 mL, 0.07 mol). After stirring at 45° C. for 2 h, the excess trifluoroacetic anhydride was removed at reduced pressure. The residue was dissolved in N,N-dimethylformamide (5 mL) and heated at 95° C. for 1 h. After cooling to room temperature, the reaction mixture was diluted with water and extracted with ethyl acetate. The combined organic layers were dried over anhydrous Na2SO4, filtered and concentrated. The solid residue was washed with ether to provide the desired product (1.50 g, 55.9%). LCMS calculated for C11H14F3N4OS: (M+H) 307.1; found 307.1. Step F 2-(Methylthio)-3-pentyl-8-(trifluoromethyl)-3,7-dihydro-6H-purin-6-one To the solution of 3-pentyl-2-thioxo-8-(trifluoromethyl)-1,2,3,7-tetrahydro-6H-purin-6-one (600 mg, 2 mmol) in a 2 M solution of sodium hydroxide in water (12.0 mL) was added dimethyl sulfate (0.30 mL, 3.2 mmol). The reaction mixture was stirred at room temperature for 1.5 h and quenched with acetic acid. The resulting solution was extracted with methylene chloride three times. The combined organic layer was dried, filtered and concentrated to give the desired product (0.60 g, 95.6%). LCMS calculated for C12H16F3N4OS: (M+H) 321.1; found 321.1. Step G (2E)-3-Pentyl-8-(trifluoromethyl)-3,7-dihydro-1H-purine-2,6-dione-2-hydrazone A mixture of 2-(methylthio)-3-pentyl-8-(trifluoromethyl)-1,2,3,7-tetrahydro-6H-purin-6-one (0.61 g, 0.95 mmol), hydrazine (3 mL, 100 mmol) and water (3 mL) was stirred at 100° C. for 1 h. The reaction solution was concentrated under reduced pressure. The residue was dissolved in DMSO and purified by preparative LCMS. The product fractions were collected and lyophilized to give the desired product (0.25 g, 65%). LCMS calculated for C11H15F3N6O: (M+H) 305.1; found 305.1. Step H 3-Methyl-9-pentyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A mixture of (2E)-3-pentyl-8-(trifluoromethyl)-3,7-dihydro-1H-purine-2,6-dione-2-hydrazone (0.020 g, 0.14 mmol) and triethyl orthoacetate (2 mL, 10 mmol) was stirred at room temperature for 1 h. The reaction mixture was concentrated under vacuum and the residue was purified by preparative LCMS. The product fractions were collected and lyophilized to yield pure product as white powder. LCMS calculated for C13H15F3N6O: (M+H) 329.1; found: 329.1. Example 2 Preparation of 9-butyl-3-methyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 1. LCMS calculated for C12H13F3N6O: (M+H) 315.1; found 315.1. Example 3 Preparation of 9-pentyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A mixture of (2E)-3-pentyl-8-(trifluoromethyl)-3,7-dihydro-1H-purine-2,6-dione-2-hydrazone (0.020 g, 0.14 mmol) and triethyl orthoformate (2 mL, 0.01 mol) was stirred at room temperature for 1 h. The reaction mixture was concentrated under vacuum and the residue was purified by preparative LCMS. The product fractions were collected and lyophilized to yield pure product as white powder (0.1 g, 48%). LCMS calculated for C12H13F3N6O: (M+H) 315.1; found: 315.1. Example 4 Preparation of 9-butyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 3. LCMS calculated for C11H11F3N6O: (M+H) 301.1; found 301.1. Example 5 Preparation of 7-bromo-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 4-(Pentylamino)-1H-imidazole-5-carboxamide 4-Amino-1H-imidazole-5-carboxamide (13.0 g, 0.104 mol) and valeraldehyde (11 mL, 0.10 mol) were mixed in methanol (200 mL). After being stirred for 30 min, sodium cyanoborohydride (6.5 g, 0.10 mol) was added to the solution and stirring was continued overnight. The reaction mixture was concentrated under reduced pressure. The remaining residue was taken up in EtOAc and the resulting solution was washed with saturated NaHCO3. The aqueous layer was extracted with EtOAc three times. The combined organic layers were dried (MgSO4) and concentrated. The residue was purified by flash chromatography (DCM to 5% MeOH/DCM) to give the desired product (12.9 g, 63.1%). LCMS calculated for C9H16N4O (M+H): 197.1; found: 180.1 (M+H−NH3). Step B 4-[[(Benzoylamino)carbonothioyl](pentyl)amino]-1H-imidazole-5-carboxamide To a solution of 4-(pentylamino)-1H-imidazole-5-carboxamide (4.0 g, 0.020 mol) in DCM (50 mL) was added benzoyl isothiocyanate (3.3 mL, 0.024 mol). After being stirred overnight, the solid formed was filtered to give the crude product (10 g, ca 60% purity, 80% yield). This product was used for next step without further purification. LCMS calculated for C17H22N5O2S (M+H): 360.1; found: 360.1. Step C 3-Pentyl-2-thioxo-1,2,3,7-tetrahydro-6H-purin-6-one A mixture of 4-[[(benzoylamino)carbonothioyl](pentyl)amino]-1H-imidazole-5-carboxamide (11.8 g, 0.0263 mol) and 1 M of sodium hydroxide in water (75 mL) was heated to reflux for 3 h. Solid was formed in the reaction mixture. The reaction mixture was adjusted to pH 3-4 with concentrated HCl with cooling in an ice bath. The solid was filtered, washed with water and air-dried to give the product (9.0 g, 65% purity, 94% yield). The product was used for the next step without further purification. LCMS calculated for C10H15N4OS (M+H): 239.1; found: 239.1. Step D (2E)-3-Pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone 3-Pentyl-2-thioxo-1,2,3,7-tetrahydro-6H-purin-6-one (6.0 g, 16 mmol) was mixed with hydrazine (10 mL, 300 mmol) and water (10 mL). The mixture was heated at 100° C. for 8 h. The solid formed was filtered and washed with water to give the desired product (3.0 g, 78%). LCMS calculated for C10H17N6O (M+H): 237.1; found: 237.1. Step E 3-Methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A mixture of (2Z)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (3.1 g, 0.013 mol) and triethyl orthoacetate (20 mL, 0.1 mol) was heated at 100° C. for 3 h. The suspension was cooled to room temperature and the solid formed was filtered and washed with DCM/Hex (1:1) mixture to provide the desired product (3.1 g, 91% yield). LCMS calculated for C12H17N6O (M+H): 261.1; found: 261.1. Step F 7-Bromo-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a solution of 3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (1.0 g, 3.8 mmol) in THF (50 mL) was added N-bromosuccinimide (0.75 g, 4.2 mol). The mixture was heated at 70° C. for 1 h and concentrated in vacuum. The residue was taken up in water and EtOAc. The organic layer was separated and the aqueous layer was extracted with ethyl acetate three times. The combined organic layers were dried (MgSO4), filtered, and concentrated in vacuum. The residue was purified by preparative LCMS to provide the desired product as a white powder (0.4 g, 30% yield). 1HNMR (400 MHz, d6-DMSO): δ 4.18 (t, J=7.5 Hz, 2H), 2.71 (s, 3H), 1.79 (m, 2H), 1.29 (m, 4H), 0.84 (m, 3H). LCMS calculated for C12H16BrN6O (M+H): 339.1, 341.1; found: 339.1, 341.1. Example 6 Preparation of 7-bromo-3-methyl-9-butyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 5. LCMS calculated for: C11H14BrN6O (M+H) 325.1, 327.1; found: 325.1, 327.1. Example 7 Preparation of 7-chloro-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a solution of 3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (0.10 g, 0.38 mmol) in THF (5 mL) in a microwave reaction tube was added N-chlorosuccinimide (0.046 g, 0.42 mmol). The mixture was heated at 70° C. in a microwave oven for 20 min. After cooling to room temperature, it was purified using preparative LCMS to provide the product (0.021 g). 1HNMR (300 MHz, CD3OD): δ 4.39 (t, J=7.5 Hz, 2H), 2.46 (s, 3H), 1.91 (m, 2H), 1.39 (m, 4H), 0.92 (m, 3H). LCMS calculated for C12H16ClN6O (M+H): 295.1; found: 295.1. Example 8 Preparation of 7-chloro-3-methyl-9-butyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 7. LCMS calculated for: C11H14ClN6O (M+H) 281.1; found: 281.1. Example 9 7-bromo-3-(methylthio)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 9-pentyl-3-thioxo-2,3,6,9-tetrahydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A solution of (2e)-3-pentyl-3,7-dihydro-1h-purine-2,6-dione 2-hydrazone (1.90 g, 8.04 mmol) and carbon disulfide (0.58 ml, 9.64 mmol) in pyridine (30 ml) was stirred at 60° C. for 3 hours. After cooling to room temperature, the solid formed was filtered and dried to yield the desired product (1.90 g, 84.9%). LCMS calculated for: C11H14N6OS (M+H) 280.1; found: 280.1. Step B 3-(methylthio)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A solution of 9-pentyl-3-thioxo-2,3,6,9-tetrahydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (1.90 g, 6.83 mmol), dimethyl sulfate (1.03 g, 8.19 mmol) and 1 m of sodium hydroxide in water (25 ml) was stirred at room temperature for 1 hour. The mixture was nutralized to pH=7. The solid formed was filtered and dried to provide the desired product (1.70 g, 85.2%). 1HNMR (300 MHz, CD3OD): δ 4.29 (t, J=7.2 Hz, 2H), 2.65 (s, 3H), 1.89 (m, 2H), 1.40 (m, 4H), 0.92 (m, 3H). LCMS calculated for: C12H17N6OS (M+H) 294.1; found: 294.1. Step C 7-bromo-3-(methylthio)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A solution of 3-(methylthio)-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (111 mg, 0.380 mmol), N-bromosuccinimide (81.1 mg, 0.456 mmol) in THF (3 ml) was stirred at 70° C. for 3 hours. The reaction was diluted with water and extracted with ethyl acetate three times, dried with sodium sulfate, filtered, and concentrated in vacuo. The crude residue was purified by Prep LCMS to yield the desired product. LCMS calculated for: C12H16BrN6OS (M+H) 371.0; found: 371.0, 373.0. Example 10 7-bromo-3-(methylsulfinyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 3-(methylsulfinyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (A1) and 3-(methylsulfonyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (A2) To a solution of 3-(methylthio)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (200 mg, 0.7 mmol) in THF (5 mL) was added m-chloroperbenzoic acid (283.3 mg, 1.64 mmol) at room temperature. After stirring at room temperature for 30 minutes, the reaction mixture was diluted with water and extracted with ethyl acetate three times. The combined organic layers were dried with sodium sulfate, filtered, and concentrated in vacuo. The crude residue was purified by flash column chromatography to yield the desired products A1 and A2 as a mixture (A1:A2=3:2) (41 mg, 8.5% for A1, 10% for A2). LCMS calculated for: C12H16N6O2S (A1) (M+H) 309.1; found: 310.1. LCMS calculated for: C12H16N6O3S (A2) (M+H) 325.1; found: 325.1. Step B 7-bromo-3-(methylsulfinyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a mixture of 3-(methylsulfinyl)-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one and 3-(methylsulfonyl)-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (3:2, 125 mg, 0.40 mmol) in THF (3 mL) was added N-bromosuccinimide (82.3 mg, 0.462 mmol). The mixture was stirred at 70° C. for 3 hours. The reaction was diluted with water and extracted with ethyl acetate three times, dried with sodium sulfate, filtered, and concentrated in vacuo. The crude residue was purified by Prep LCMS to yield the desired product. LCMS calculated for: C12H15BrN6O2S (M+H) 387.0; found: 387.0, 389.0. Example 11 7-bromo-3-(methylsulfonyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 10. LCMS calculated for: C12H15BrN6O3S (M+H) 403.0; found: 403.0, 405.0. Example 12 7-bromo-3-hydroxy-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 3-hydroxy-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A solution of (2z)-3-pentyl-3,7-dihydro-1h-purine-2,6-dione 2-hydrazone (200 mg, 0.846 mmol), N,N-carbonyldiimidazole (1.65 g, 10.2 mmol) in THF (10 ml) was stirred at 70° C. overnight. The reaction mixture was then heated in microwave reactor at 100° C. for 10 min. The reaction was completed checked by LCMS analysis. The reaction mixture was concentrated, diluted with EtOAc and washed with sat. NaHCO3. The aqueous was extracted with EtOAc (3×). The combined organic layers were dried (MgSO4) and concentrated to yield the desired product (230 mg, 98.4%). LCMS calculated for C11H15N6O2 (M+H) 263.1; found: 263.1. Step B 7-bromo-3-hydroxy-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of solution of 3-hydroxy-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (100 mg, 0.381 mmol) and N-bromosuccinimide (204 mg, 1.14 mmol) in THF (2 ml) was stirred in a microwave reactor at 70° C. for 10 min. The reaction mixture was filtrated and the filtrate was purified by prep LCMS to yield the desired product. LCMS calculated for C11H14BrN6O2 (M+H) 341.0; found: 341.0, 343.0. Example 13 7-bromo-9-butyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 9-butyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of (2E)-3-butyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (200 mg, 0.0009 mol) in Ethyl orthoformate (5 mL, 0.03 mol) was heated at 100° C. overnight. After cooling to room temperature, the reaction mixture was filtrated and dried to give the desired product (150 mg, 71.8%). LCMS calculated for C10H13N6O (M+H): 233.1; found: 233.1. Step B 7-bromo-9-butyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a mixture of 9-butyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (65 mg, 0.28 mmol) in THF (2 mL) was added N-bromosuccinimide (49.8 mg, 0.280 mmol). The mixture was heated in a microwave reactor at 70° C. for 10 minutes. The mixture was purified with prep LCMS to give the desired product (4.8 mg, 6%). LCMS calculated for C10H12BrN6O (M+H): 311.0; found: 311.0, 313.0. Example 14 7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 13. LCMS calculated for: C11H13BrN6O (M+H) 325.0; found: 325.0, 327.0. Example 15 7-bromo-9-pentyl-3-(methoxymethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 9-butyl-3-(methoxymethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of 9-butyl-3-(chloromethyl)-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (35 mg, 125 mmol) in 4 M of sodium methoxide in methanol (0.5 mL, 2 mmol) was stirred at room temperature overnight. The reaction mixture was diluted with water and extracted with ethyl acetate three times. The combined organic layers was dried with sodium sulfate, filtered, and concentrated in vacuo to yield the desired product (6 mg, 17.42%). LCMS calculated for C13H19N6O2 (M+H): 290.2; found 290.2. Step B 7-bromo-9-butyl-3-(methoxymethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of 9-butyl-3-(methoxymethyl)-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (6 mg, 21.7 mmol), N-bromosuccinimide (4.64 mg, 26.0 mmol) in tetrahydrofuran (10 ml) was stirred at 70° C. for 2 hours. The reaction mixture was concentrated in vacuo and the residue was purified by prep LCMS to yield the desired product. LCMS calculated for C13H18BrN6O2 (M+H): 369.1; found 371.1. Example 16 7-bromo-9-pentyl-3-phenyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A benzaldehyde [(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]hydrazone A solution of (2E)-3-pentyl-3,7-dihydro-1h-purine-2,6-dione 2-hydrazone (104 mg, 44 μmol), benzaldehyde (44.7 μl, 44 μmol) in ethanol (10 ml) was stirred at 70° C. for 3 hours. The reaction solution was concentrated in vacuo to give the desired product. LCMS calculated for C17H21N6O (M+H): 325.2; found: 325.2. Step B 9-pentyl-3-phenyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A solution of benzaldehyde [(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2h-purin-2-ylidene]hydrazone (140 mg, 0.432 mmol) in acetic acid (5 ml) was stirred at 130° C. for 5 hours. The reaction mixture was concentrated in vacuo and purified by prep LCMS to yield the desired product (30 mg, 22% yield). LCMS calculated for C17H19N6O (M+H): 323.2; found: 323.2. Step C 7-bromo-9-pentyl-3-phenyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a mixture of 9-pentyl-3-phenyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (30 mg, 0.093 mmol) in THF (30 mL) was added N-bromosuccinimide (19.9 mg, 0.112 mmol). The mixture was stirred at 70° C. for 3 hours. The reaction mixture was concentrated in vacuo and the crude residue was purified using preparative LCMS to yield the desired product (8.7 mg, 23.3% yield). LCMS calculated for C17H18BrN6O (M+H): 401.1; found 401.1, 403.1 Example 17 7-bromo-9-pentyl-3-pyridin-3-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 16. LCMS calculated for C16H17BrN7O (M+H): 402.1; found: 402.1, 404.1. Example 18 7-bromo-9-pentyl-3-pyridin-4-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 16. LCMS calculated for C16H17BrN7O (M+H): 402.1; found: 402.1, 404.1. Example 19 7-bromo-9-pentyl-3-pyridin-2-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 16. LCMS calculated for C16H17BrN7O (M+H): 402.1; found: 402.1, 404.1. Example 20 7-bromo-9-pentyl-3-(1,3-thiazol-2-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 16. LCMS calculated for C14H15BrN7OS (M+H): 408.0; found: 408.1. Example 21 7-bromo-9-pentyl-3-propyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 5. LCMS calculated for C14H20BrN6O: 367.1; found; 367.1, 369.1. Example 22 7-bromo-3-[(dimethylamino)methyl]-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The mixture of 7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (130 mg, 0.40 mmol) and Eschenmoser's salt (1.1 eq.) in DMF (5 mL) was heated at 100° C. for 30 minutes. The reaction mixture was directly purified using preparative LCMS to yield the desired product. LCMS calculated for C14H21BrN7O: 382.1; found 382.1, 384.1. Example 23 3-methyl-9-pentyl-7-(1,3-thiazol-2-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 7-bromo-6-(4-methoxybenzyl)-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of 7-bromo-3-methyl-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (200 mg, 0.59 mmol), 4-methoxyphenyl methylbromide (0.094 mL, 0.65 mmol), potassium carbonate (244 mg, 1.77 mmol) in DMF (10 ml) was stirred at room temperature for 2 hours. The reaction was quenched with water and the solid formed was filtered and dried over to yield the desired product (270 mg, 99.7%). LCMS calculated for C20H24BrN6O2: 459.1; found 460.1. Step B 6-(4-methoxybenzyl)-3-methyl-9-pentyl-7-(1,3-thiazol-2-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To the mixture of 7-bromo-6-(4-methoxybenzyl)-3-methyl-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (100 mg, 0.22 mmol), 2-(tributylstannyl)-1,3-thiazole (122 mg, 0.33 mmol) in toluene (14 mL) was added tetrakis(triphenylphosphine)palladium(0) (12.6 mg, 0.011 mmol) under N2. The mixture was refluxed overnight. The reaction mixture was concentrated in vacuo. The crude residue was purified using preparative LCMS to yield the desired product (80 mg, 79%). LCMS calculated for C23H26N7O2S (M+H): 464.2; found 464.2. Step C 3-methyl-9-pentyl-7-(1,3-thiazol-2-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of 6-(4-methoxybenzyl)-3-methyl-9-pentyl-7-(1,3-thiazol-2-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (100 mg, 0.22 mmol) in trifluoroacetic acid (5 mL, 65 mmol) was stirred at 55° C. overnight. The reaction solution was concentrated and purified using preparative LCMS to yield the desired product. LCMS calculated for C15H18N7OS: 344.1; found: 344.1. Example 24 3-methyl-7-(methylthio)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 6-(4-methoxybenzyl)-3-methyl-7-(methylthio)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A mixture of 7-bromo-6-(4-methoxybenzyl)-3-methyl-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (271 mg, 0.6 mmol) and sodium methyl sulfide (45.5 mg, 0.65 mmol) in dimethoxyethane (13.4 ml, 129 mmol) was refluxed for 2 h. The reaction was quenched with water. The solid formed was filtered and dried to yield the desired product (200 mg, 79.5%). LCMS calculated for C21H27N6O2S (M+H): 427.2; found 427.2. Step B 3-methyl-7-(methylthio)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A solution of 6-(4-methoxybenzyl)-3-methyl-7-(methylthio)-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (200 mg, 469 mmol) in trifluoroacetic acid (5 ml, 64.9 mmol) was stirred at 55° C. overnight. The solution was concentrated and purified by prep LCMS to yield the desired product (60 mg, 42%). 1HNMR (300 MHz, CD3OD): δ 4.42 (t, J=7.5 Hz, 2H), 2.74 (s, 3H), 2.45 (s, 3H), 1.92 (m, 2H), 1.39 (m, 4H), 0.92 (m, 3H). LCMS calculated for C13H19N6OS (M+H): 307.1; found 307.1. Example 25 3-methyl-9-pentyl-7-phenyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a mixture of 7-bromo-3-methyl-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (100 mg, 0.30 mmol), phenylboronic acid (39.5 mg, 0.32 mmol), sodium carbonate (100 mg, 0.94 mmol) in water (2 ml) and 1,2-dimethoxyethane (20 ml) was added tetrakis(triphenylphosphine)-palladium(0) (200 mg, 0.10 mmol). The mixture was heated to reflux overnight. The reaction mixture was diluted with water and extracted with ethyl acetate three times. The combined organic layers were dried with sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by preparative LCMS to yield the desired product (16 mg, 16%). 1HNMR (400 MHz, CD3OD): δ 8.06 (m, 2H), 7.49 (m, 3H), 4.38 (t, J=8.0 Hz, 2H), 2.83 (s, 3H), 1.95 (m, 2H), 1.42 (m, 4H), 0.92 (m, 3H). LCMS calculated for C18H21N6O (M+H): 337.2; found 337.2. Example 26 3-methyl-9-pentyl-7-pyridin-4-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate To a mixture of 7-bromo-3-methyl-9-pentyl-6,9-dihydro-5h-[1,2,4]triazolo[4,3-a]purin-5-one (100 mg, 0.30 mmol), 4-pyridinylboronic acid (40 mg, 0.32 mmol), sodium carbonate (100 mg, 0.94 mmol) in water (2 ml) and toluene (20 ml) was added tetrakis(triphenylphosphine)palladium(0) (200 mg, 0.10 mmol). The mixture was heated to reflux overnight. The reaction mixture was diluted with water and extracted with ethyl acetate three times. The combined organic layers were dried with sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by preparative LCMS to yield the desired product (16 mg, 16%). 1HNMR (400 MHz, CD3OD): δ 8.83 (dd, J=1.6, 4.9 Hz, 2H), 8.33 (dd, J=1.6, 4.9 Hz, 2H), 4.44 (t, J=7.7 Hz, 2H), 2.88 (s, 3H), 1.97 (m, 2H), 1.44 (m, 4H), 0.93 (m, 3H). LCMS calculated for C17H20N7O (M+H): 338.2; found 338.2. Example 27 7-(3,5-dimethylisoxazol-4-yl)-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 25. LCMS calculated for C17H22N7O2 (M+H): 356.2; found 356.2. Example 28 7-cyclopropyl-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 25. 1HNMR (300 MHz, d6-DMSO): δ 4.18 (d, J=7.5 Hz, 2H), 2.70 (s, 3H), 2.05 (m, 1H), 1.78 (m, 2H), 1.28 (m, 4H), 1.06 (m, 4H), 0.92 (m, 3H). LCMS calculated for C15H21N6O (M+H): 301.2; found 301.2. Example 29 3-methyl-7-(1-methyl-1H-pyrazol-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 6-(4-methoxybenzyl)-3-methyl-7-(1-methyl-1H-pyrazol-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a solution of 7-bromo-6-(4-methoxybenzyl)-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (100 mg, 0.3 mmol), 1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (92 mg, 0.44 mmol) and sat. sodium carbonate (100 mg, 0.9 mmol) in toluene (20 mL, 0.2 mol) was added tetrakis(triphenylphosphine)palladium(0) (20 mg, 0.01 mmol) under N2 at room temperature. The mixture was heated to reflux overnight. The mixture was stripped down and purified by preparative LC-MS to yield the desired product (50 mg, 37%). LCMS calculated for C24H29N8O2 (M+H): 461.2; found 461.2. Step B 3-methyl-7-(1-methyl-1H-pyrazol-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one 6-(4-Methoxybenzyl)-3-methyl-7-(1-methyl-1H-pyrazol-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (50 mg, 0.10 mmol) in trifluoroacetic acid (5 mL) was stirred at 60° C. overnight. The mixture was concentrated, and the residue was purified by preparative LC-MS to give final product. 1HNMR (300 MHz, CD3OD): δ 8.23 (d, J=4.9 Hz, 1H), 8.05 (d, J=4.9 Hz, 1H), 4.45 (t, J=7.0 Hz, 2H), 3.98 (s, 3H), 2.46 (s, 3H), 1.93 (m, 2H), 1.41 (m, 4H), 0.92 (m, 3H). LCMS calculated for C16H21N8O (M+H): 341.2; found 341.2. Example 30 3-methyl-9-pentyl-7-(4H-1,2,4-triazol-4-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 6-(4-methoxybenzyl)-3-methyl-9-pentyl-7-(4H-1,2,4-triazol-1-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Sodium hydride 60% in mineral oil (18 mg, 0.74 mmol) was added to a solution of 1H-1,2,4-Triazole (45 mg, 0.65 mmol) in DMF (10 mL) at room temperature. After stirring for 1 hour at room temperature, 7-bromo-6-(4-methoxybenzyl)-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (200 mg, 0.40 mmol) in DMF was added to above solution and the mixture was stirred overnight. The reaction was quenched with a drop of water and the reaction mixture was purified by pre LC-MS to give the desired product (53 mg, 27.2%) and its region-isomer 6-(4-methoxybenzyl)-3-methyl-9-pentyl-7-(1H-1,2,4-triazol-1-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (53 mg, 27%). LCMS calculated for C22H26N9O2 (M+H): 448.2; found 448.2. Step B 3-methyl-9-pentyl-7-(4H-1,2,4-triazol-4-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A mixture of 6-(4-methoxybenzyl)-3-methyl-9-pentyl-7-(1H-1,2,4-triazol-1-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (53 mg, 0.12 mmol) in trifluoroacetic acid (10 mL) was stirred at 60° C. overnight. The mixture was concentrated and purified by preparative LC-MS to give the desired product (20 mg, 52%). LCMS calculated for C14H18N9O (M+H): 328.2; found: 328.2. Example 31 3-methyl-9-pentyl-7-(1H-1,2,4-triazol-1-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 30. LCMS calculated for C14H18N9O (M+H): 328.2; found: 328.2. Example 32 7-cyclobutyl-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A N-(5-amino-6-oxo-3-pentyl-2-thioxo-1,2,3,6-tetrahydropyrimidin-4-yl)cyclobutanecarboxamide The mixture of 5,6-diamino-1-pentyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-one (1060 mg, 0.00464 mol), cyclobutane carboxylic acid (0.55 g, 5.5 mmol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (2.2 g, 5.1 mmol) and triethylamine (1.3 mL, 9.3 mmol) in DMF (20 mL) was stirred at room temperature for 4 hours. The mixture was diluted with water. The precipitate formed was filtered and dried to yield the desired product (1.20 g, 83.27%). LCMS calculated for C14H23N4O2S (M+H): 311.2; found 311.2. Step B 8-cyclobutyl-3-pentyl-2-thioxo-1,2,3,7-tetrahydro-6H-purin-6-one The mixture of N-(5-amino-6-oxo-3-pentyl-2-thioxo-1,2,3,6-tetrahydropyrimidin-4-yl)cyclobutanecarboxamide (720 mg, 2.3 mmol) and 2.5 M of sodium hydroxide in water (25 mL) and methanol (25 mL) was stirred at 70° C. for 1 hour. After cooling to room temperature, The reaction mixture was concentrated to remove methanol and then acidified to pH=5. The precipitate formed was filtered and dried to yield the desired product (500 mg, 73.7%). LCMS calculated for C14H21N4OS (M+H): 293.1; found: 293.1. Step C (2E)-8-cyclobutyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone The mixture of 8-cyclobutyl-3-pentyl-2-thioxo-1,2,3,7-tetrahydro-6H-purin-6-one (0.6 g, 2.0 mmol) in 20 M of hydrazine in water (20 mL) was stirred at 100° C. overnight. After cooling to room temperature, the solid formed was filtered and dried Cooled down, the solid was isolated to give yield the desired product (230 mg, 38.6%). LCMS calculated for C14H23N6O (M+H): 291.2; found: 291.2. Step D 7-cyclobutyl-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (2E)-8-cyclobutyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (100 mg, 0.0003 mol) was mixed with triethyl orthoacetate (10 mL, 0.05 mol) and then stirred at 100° C. overnight. After cooling to room temperature, the mixture was concentrated and purified by preparative LCMS to yield the desired product (10 mg, 9.2%). 1HNMR (300 MHz, CD3OD): δ 4.35 (m, 2H), 3.72 (m, 1H), 2.84 (s, 3H), 2.44 (m, 4H), 2.05 (m, 2H), 1.90 (m, 2H), 1.40 (m, 4H), 0.92 (m, 3H). LCMS calculated for C16H23N6O (M+H): 315.2; found: 315.2. Example 33 7-bromo-3-(4-methoxyphenyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 16. 1HNMR (300 MHz, CD3OD): δ 7.67 (d, J=9.2 Hz, 2H), 7.03 (d, J=9.2 Hz, 2H), 4.41 (t, J=7.8 Hz, 2H), 3.88 (s, 3H), 1.96 (m, 2H), 1.44 (m, 4H), 0.94 (m, 3H). LCMS calculated for C18H20BrN6O2 (M+H): 431.1; found 431.1. Example 34 7-bromo-9-pentyl-3-(4-(trifluoromethyl)phenyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 16. 1HNMR (300 MHz, CD3OD): δ 7.94 (d, J=8.6 Hz, 2H), 7.78 (d, J=9.2 Hz, 2H), 4.44 (t, J=7.3 Hz, 2H), 1.97 (m, 2H), 1.44 (m, 4H), 0.94 (m, 3H). LCMS calculated for C18H16BrF3N6O (M+H): 469.1; found 469.1. Example 35 7-bromo-3-(4-methoxybenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 2-(4-methoxyphenyl)-N-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]acetohydrazide The mixture of (2E)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (0.30 g, 1.3 mmol), benzeneacetic acid, 4-methoxy- (0.23 g, 1.4 mmol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (0.62 g, 1.40 mol) and triethylamine (0.53 mL, 3.8 mmol) in DMF (10 mL) were stirred at room temperature overnight. The reaction mixture was diluted with ethyl acetate and washed sat. NaHCO3. The aqueous was extracted with ethyl acetate (3×). The combined organic layers were dried (MgSO4), filtered and concentrated to yield the desired product (560 mg, 98%). LCMS calculated for C19H25N6O3 (M+H): 385.2; found: 385.2. Step B 3-(4-methoxybenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of 2-(4-methoxyphenyl)-N′-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]acetohydrazide (0.66 g, 1.4 mmol) in toluene (30 mL) was refluxed overnight. The reaction mixture was concentrated to give the crude product as a solid. The solid was washed with ethyl acetate and dried to yield the desired product (490 mg, 92%). LCMS calculated for C19H23N6O2 (M+H): 367.2; found: 367.2. Step C 7-bromo-3-(4-methoxybenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To the solution of 3-(4-methoxybenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (0.40 g, 1.1 mmol) in THF was added N-Bromosuccinimide (0.29 g, 1.6 mol). The mixture was stirred at 70° C. for 1 hour. The mixture was concentrated and purified by preparative LCMS to yield the desired product (290 mg, 60%). 1HNMR (300 MHz, d6-DMSO): δ 7.16 (d, J=8.3 Hz, 2H), 6.81 (d, J=8.3 Hz, 2H), 4.46 (s, 3H), 4.20 (t, J=7.2 Hz, 2H), 3.67 (s, 2H), 1.79 (m, 2H), 1.28 (m, 4H), 0.83 (m, 3H). LCMS calculated for C19H21BrN6O2 (M+H): 445.1; found: 445.0, 447.0. Example 36 7-bromo-9-pentyl-3-(3-bromobenzyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 2-(3-bromophenyl)-N′-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]acetohydrazide The mixture of (2E)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (0.30 g, 1.3 mmol), (3-bromophenyl)acetic acid (0.30 g, 1.4 mol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (0.62 g, 1.4 mol) and triethylamine (0.53 mL, 3.8 mmol) in DMF (10 mL) were stirred at rt overnight. The reaction mixture was diluted with EtOAc. The solid was filtered, washed with EA and dried to yield the desired product (430 mg, 78.2%). LCMS calculated for C18H22BrN6O2 (M+H): 433.1; found: 433.1. Step B 3-(3-bromobenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of 2-(3-bromophenyl)-N′-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]acetohydrazide (1.8 g, 4.2 mmol) in benzene (100 mL) was refluxed overnight. The reaction mixture was concentrated to give the desired product 1.5 g. LCMS calculated for C18H20BrN6O (M+H): 415.1; found: 415.1. Step C 7-bromo-9-pentyl-3-(3-bromobenzyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To the solution of 3-(3-bromobenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (210 mg, 0.50 mmol) in tetrahydrofuran (20 mL) was added N-bromosuccinimide (140 mg, 0.00076 mol). The mixture was stirred at 70° C. for 1 hour. The reaction mixture was concentrated and the residue was purified by preparative LCMS to yield the desired product (0.15 g, 60%). 1HNMR (300 MHz, d6-DMSO): δ 7.16 (d, J=8.3 Hz, 2H), 6.81 (d, J=8.3 Hz, 2H), 4.46 (s, 3H), 4.20 (t, J=7.2 Hz, 2H), 3.67 (s, 2H), 1.79 (m, 2H), 1.28 (m, 4H), 0.83 (m, 3H). LCMS calculated for C18H19Br2N6O (M+H): 493; found: 493, 495 and 497. Example 37 7-bromo-9-pentyl-3-(3-pyrimidin-5-ylbenzyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 1535. LCMS calculated for C23H21BrN8O (M+H): 493.1; found: 493.1, 495.1. Example 38 7-bromo-9-pentyl-3-pyrimidin-4-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. 1HNMR (400 MHz, CD3OD): δ 9.30 (d, J=1.3 Hz, 1H), 8.96 (d, J=5.2 Hz, 1H), 7.96 (d, J=5.3, 1.3 Hz, 1H), 4.47 (t, J=7.4 Hz, 2H), 1.99 (m, 2H), 1.46 (m, 4H), 0.96 (m, 3H). LCMS calculated for C15H15BrN8O (M+H): 403.1; found: 403.1, 405.1. Example 39 7-bromo-9-pentyl-3-pyrazin-2-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 35. 1HNMR (400 MHz, CD3OD): δ 9.30-9.25 (d, J=1.0 Hz, 1H), 8.95-8.90 (dd, J=1.0, 3.0 Hz, 1H), 7.95-7.91 (dd, J=1.0, 3.0 Hz, 1H), 4.50-4.40 (m, 2H), 2.00-1.90 (m, 2H), 1.48-1.40 (m, 4H), 0.95-0.90 (m, 3H). LCMS calculated for C15H15BrN8O (M+H): 403.1; found: 403.1, 405.1. Example 40 7-bromo-3-cyclopropyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 16. 1HNMR (300 MHz, d6-DMSO): δ 4.18 (t, J=7.6 Hz, 3H), 2.82 (m, 1H), 1.77 (m, 2H), 1.28 (m, 4H), 0.99 (m, 4H), 0.83 (m, 3H). LCMS calculated for C14H17BrN6O (M+H): 365.1; found: 365.1, 365.1. Example 41 7-bromo-3-(dimethylamino)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoracetate Step A 3-(dimethylamino)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To methylene chloride (10 mL) was added [B] N-(dichloromethylene)-N-methylmethanaminium chloride (0.21 g, 1.3 mmol). After stirring for 5 mins, (2Z)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (0.10 g, 0.42 mmol) was added, and the mixture was stirred at rt for 5 hrs. LCMS analysis showed product as a major peak was formed. 1N NaoH was carefully added to neutralize the acid, and the mixture was extracted with methylene chloride three times. The combined organic layers were dried by MgSO4, filtered and concentrated in vacuo to yield the desired product (84 mg, 69%). LCMS calculated for C13H20N7O (M+H): 290.2; found 290.1. Step B 7-bromo-3-(dimethylamino)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate To a mixture of 3-(dimethylamino)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (80 mg, 0.28 mmol) in Tetrahydrofuran (20 mL) was added N-Bromosuccinimide (59 mg, 0.33 mol). The mixture was stirred at 70° C. for 1 hour. The reaction mixture was concentrated and purified by preparative LCMS to provide the desired product. LCMS calculated for C13H19BrN7O (M+H): 368.1; found: 368.0, 370.0. Example 42 7-bromo-9-pentyl-3-(3,3,3-trifluoropropyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 16. LCMS calculated for C14H16BrF3N6O (M+H): 421.1; found: 421.1, 423.1. Example 43 7-bromo-9-pentyl-3-(2-phenylethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 16. 1HNMR (300 MHz, CD3OD): δ 7.23 (m, 5H), 4.32 (t, J=8.0 Hz, 2H), 3.53 (t, J=8.0 Hz, 2H), 3.11 (t, J=8.0 Hz, 2H), 1.90 (m, 2H), 1.40 (m, 4H), 0.92 (m, 3H). LCMS calculated for C19H21BrN6O (M+H): 429.1; found: 429.1, 431.1. Example 44 7-bromo-9-pentyl-3-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 9-pentyl-3-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of (2E)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (200 mg, 0.85 mol) in trifluoroacetic acid (10 mL) was refluxed overnight. The reaction mixture was concentrated and purified by preparative LCMS to yield the desired product (160 mg, 60.2%). LCMS calculated for C12H14F3N6O (M+H): 315.1; found 315.0. Step B 7-bromo-9-pentyl-3-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To the mixture of 9-pentyl-3-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (50 mg, 0.16 mmol) in tetrahydrofuran (10 mL) was added N-bromosuccinimide (42 mg, 0.24 mmol). The mixture was stirred at 70° C. for 3 hour. The reaction mixture was concentrated and purified by preparative LCMS to yield the desired product. 1HNMR (300 MHz, CD3OD): δ 4.44 (t, J=7.6 Hz, 2H), 1.94 (m, 2H), 1.42 (m, 4H), 0.93 (m, 3H). LCMS calculated for C12H13BrF3N6O (M+H): 393.0, found: 393.0, 395.0. Example 45 7-bromo-9-pentyl-3-(pyridine-4-ylmethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 35. LCMS calculated for C17H18BrN7O (M+H): 416.1; found: 416, 418. Example 46 7-bromo-9-pentyl-3-(2-pyridine-3-ylethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 35. LCMS calculated for C18H20BrN7O (M+H): 429.1; found: 430.0, 432.0. Example 47 7-bromo-9-pentyl-3-(1-phenylcyclopropyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. LCMS calculated for C20H21BrN6O (M+H): 441.1; found: 441.0, 443.0. Example 48 7-bromo-3-(2-methylpyridin-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 16. LCMS calculated for C17H18BrN7O (M+H): 416.1; found: 416.0, 418.0. Example 49 7-bromo-3-(3-fluoropyridin-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 16. LCMS calculated for C16H15BrFN7O (M+H): 421.1; found: 421.0, 423.0. Example 50 7-bromo-3-(3-fluorobenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. LCMS calculated for C18H18BrFN6O (M+H): 433.1; found: 433.0, 435.0. Example 51 7-bromo-3-(3-methoxybenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. LCMS calculated for C19H21BrN6O2 (M+H): 445.1; found: 445.1, 447.0. Example 52 7-bromo-3-(1,3-oxazol-4-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. 1HNMR (300 MHz, CD3OD): δ 8.68 (d, J=0.9 Hz, 1H), 8.33 (d, J=0.9 Hz, 1H), 4.40 (t, J=7.3 Hz, 2H), 1.95 (m, 2H), 1.42 (m, 4H), 0.93 (m, 3H). LCMS calculated for C14H14BrN7O2 (M+H): 392.1; found: 392.0, 394.0. Example 53 7-bromo-3-isoxazol-3-yl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. 1HNMR (300 MHz, CD3OD): δ 8.85 (d, J=1.8 Hz, 1H), 6.97 (d, J=1.8 Hz, 1H), 4.45 (t, J=7.5 Hz, 2H), 1.96 (m, 2H), 1.43 (m, 4H), 0.94 (m, 3H). LCMS calculated for C14H14BrN7O2 (M+H): 392.1; found: 392.0, 394.0. Example 54 7-bromo-3-(1-methyl-1H-imidazol-2-yl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 35. LCMS calculated for C15H17BrN8O (M+H): 405.1; found: 405.0, 407.0. Example 55 7-bromo-9-pentyl-3-(3-pyridin-4-ylbenzyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 35. LCMS calculated for C23H22BrN7O (M+H): 492.1; found: 492.1, 494.1. Example 56 7-bromo-3-(2-methoxybenzyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. LCMS calculated for C19H21BrN6O2 (M+H): 445.1; found: 445.0, 447.0. Example 57 1-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)cyclopropanecarboxamide The title compound was prepared using procedures analogous to those described for Example 35. 1HNMR (300 MHz, CD3OD): δ 4.35 (t, J=7.0 Hz, 2H), 1.92 (m, 2H), 1.68 (m, 2H), 1.51 (m, 2H), 1.43 (m, 4H), 0.94 (m, 3H). LCMS calculated for C15H18BrN7O2 (M+H): 408.1; found: 408.0, 410.0. Example 58 1-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)cyclopropanecarboxylic acid The title compound was prepared using procedures analogous to those described for Example 35. 1HNMR (300 MHz, CD3OD): δ 4.35 (t, J=7.3 Hz, 2H), 1.91 (m, 2H), 1.72 (m, 2H), 1.62 (m, 2H), 1.41 (m, 4H), 0.92 (m, 3H). LCMS calculated for C15H17BrN6O3 (M+H): 409.1; found: 409.0, 411.0. Example 59 7-bromo-9-pentyl-3-[1-(trifluoromethyl)cyclopropyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. 1HNMR (300 MHz, CD3OD): δ 4.37 (t, J=7.7 Hz, 2H), 1.91 (m, 2H), 1.62 (m, 2H), 1.54 (m, 2H), 1.41 (m, 4H), 0.92 (m, 3H). LCMS calculated for C15H16BrF3N6O (M+H): 433.1; found: 433.0, 435.0. Example 60 7-bromo-3-(2,3-dihydro-1,4-benzodioxin-6-ylmethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. 1HNMR (300 MHz, d6-DMSO): δ 6.71 (m, 3H), 4.41 (s, 2H), 4.20 (t, J=7.7 Hz, 2H), 4.15 (s, 4H), 1.79 (m, 2H), 1.29 (m, 4H), 0.84 (m, 3H). LCMS calculated for C20H21BrN6O3 (M+H): 473.1; found: 473.0, 475.0. Example 61 7-bromo-3-[(3-oxo-3,4-dihydro-2H-1,4-benzoxazin-6-yl)methyl])-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. LCMS calculated for C20H20BrN7O3 (M+H): 486.1; found: 486.0, 488.0. Example 62 3-Benzyl-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 16. LCMS calculated for C18H19BrN6O (M+H): 415.1; found: 415.0, 417.0. Example 63 7-bromo-3-ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 5. 1HNMR (400 MHz, d6-DMSO): δ 4.18 (t, J=7.0 Hz, 2H), 3.33 ((br, 1H), 3.14 (dd, J=7.5 Hz, 2H), 1.78 (m, 2H), 1.27 (m, 7H), 0.83 (m, 3H). LCMS calculated for C18H19BrN6O (M+H): 353.1; found: 353.0, 353.0. Example 64 6-bromo-4-pentyl-4,7-dihydro-8H-tetrazolo[1,5-a]purin-8-one Step A 4-pentyl-4,7-dihydro-8H-tetrazolo[1,5-a]purin-8-one A saturated aqueous NaNO2 (130 mg, 1.89 mmol) solution was added dropwise to a solution of (2E)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (150 mg, 0.63 mmol) in 5% aqueous HCl solution (3 ml) under stirring at room temperature. The mixture was stirred at room temperature for 1 hour. The mixture was neutralized by saturated NaHCO3 solution and extracted by ethyl acetate (3×). The combined organic phases were washed by brine and dried over MgSO4. The filtration and evaporation of solvent gave the desired product (94.6 mg, 60.7%) as white solid. LCMS calculated for C10H14N7O (M+H): 248.1; found: 248.0. Step B 6-bromo-4-pentyl-4,7-dihydro-8H-tetrazolo[1,5-a]purin-8-one The mixture of 4-pentyl-4,7-dihydro-8H-tetrazolo[1,5-a]purin-8-one (94.6 mg, 0.38 mmol) and NBS (75 mg, 0.42 mmol) in THF (20 ml) was stirred at 70° C. for 1 hour. After evaporation of solvent, the residue was purified by preparative LC-MS to yield the desired product (17.1 mg, 13.7%). LCMS calculated for C10H13BrN7O (M+H): 326.0; found: 326.0. Example 65 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)propanoic acid Step A (4E)-4-[(2E)-(6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene)hydrazono]butanoic acid The mixture of (2E)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (1.0 g, 4.2 mmol) and 4-oxobutanoic acid (3.4 g, 15% in water, 5.1 mmol) in EtOH (70 ml) was refluxed for 1.5 hours. Evaporation of solvent gave the desired product (1.3 g, 96%) as a yellowish solid. LCMS calculated for C14H21N6O3 (M+H): 321.1; found: 321.1. Step B 3-(5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)propanoic acid The mixture of (4E)-4-[(2E)-(6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene)hydrazono]butanoic acid (1.367 g, 5.1 mmol) in acetic acid (70 ml) was refluxed for 1 hour. Evaporation of solvent afforded the desired product (1.29 g, 99%) as yellowish solid. LCMS calculated for C14H19N6O3 (M+H): 319.2; found: 319.2. Step C 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)propanoic acid The mixture of 3-(5-oxo-9-pentyl-6,9-dihydro-5H[1,2,4]triazolo[4,3-a]purin-3-yl)propanoic acid (203 mg, 0.64 mmole) and NBS (125.8 mg, 7.0 mmol) in THF (25 ml) was stirred at 70° C. for 2 hours. After evaporation of solvent, the residue was purified by preparative LC-MS to afford 60.2 mg (23.7%) of the desired product (60.2 mg, 23.7%) as white solid. LCMS calculated for C14H18BrN6O3 (M+H): 397.1; found: 371.1. Example 66 7-bromo-3-(3-morpholin-4-yl-3-oxopropyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H[1,2,4]triazolo[4,3-a]purin-3-yl]propanoic acid (50 mg, 0.126 mmol), morpholine (21.0 mg, 0.252 mmol), triethylamine (25.5 mg, 0.252 mmol) and BOP (61.5 mg, 0.139 mmol) in CH2Cl2 (10 ml) was stirred at room temperature for 2 hours. After evaporation of solvent, the residue was purified by preparative LC-MS to afford the desired product (37.2 mg, 60%) as white solid. LCMS calculated for C18H25BrN7O3 (M+H): 466.1; found: 466.1. Example 67 N-benzyl-3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)propanamide The title compound was prepared using procedures analogous to those described for Example 66. 1HNMR (400 MHz, d6-DMSO): δ 8.43 (m, 1H), 7.25 (m, 5H), 4.22 (m, 4H), 3.42 (m, 2H), 2.68 (m, 2H), 1.79 (m, 2H), 1.30 (m, 4H), 0.84 (m, 3H). LCMS calculated for C21H25BrN7O2 (M+H): 486.1; found: 486.1, 488.0. Example 68 7-bromo-3-(3-oxo-3-pyrrolidin-1-ylpropyl)-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 66. 1HNMR (400 MHz, d6-DMSO): δ 4.19 (t, J=7.2 Hz, 2H), 3.40 ((m, 4H), 3.26 (t, J=6.8 Hz, 2H), 2.73 (t, J=7.2 Hz, 2H), 1.80 (m, 6H), 1.29 (m, 4H), 0.83 (m, 3H). LCMS calculated for C19H26BrN6O2 (M+H): 449.130; found 449.1, 451.1. Example 69 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-3-yl)-N-methylpropanamide The title compound was prepared using procedures analogous to those described for Example 66. LCMS calculated for C16H22BrN6O2 (M+H): 409.1; found: 409.1, 411.1. Example 70 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)-N-(2-phenylethyl)propanamide The title compound was prepared using procedures analogous to those described for Example 66. 1HNMR (400 MHz, d6-DMSO): δ 8.01 (t, J=5.3 Hz, 1H), 7.26 (dd, J=5.3, 6.9 Hz, 2H), 7.17 (d, J=6.9, 2H), 4.20 (t, J=7.2 Hz, 2H), 3.23 (m, 2H), 2.66 (t, J=8.3 Hz, 2H), 2.57 (t, J=8.3 Hz, 2H), 1.78 (m, 2H), 1.29 (m, 4H), 0.83 (m, 3H). LCMS calculated for C22H27BrN7O2 (M+H): 500; found: 500.1, 502.1. Example 71 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)-N-(pyridin-4-ylmethyl)propanamide trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 66. LCMS calculated for C20H24BrN8O2 (M+H): 487.1; found 487.1, 489.0. Example 72 3-[2-(3-benzyl-1,2,4-oxadiazol-5-yl)ethyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one 3-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)propanoic acid (50 mg, 0.126 mmole) and CDI (21.8 mg, 0.139 mmole) were mixed in anhydrous DMF (4 ml). After stirring the solution for 3 hours at room temperature, benzylamidoxime (22.5 mg, 0.139 mmole) was added and the solution heated at 90° C. for 20 hours, then at 110° C. for 4 hours. After evaporation of solvent, the residue was purified by preparative LCMS to yield the desired product (8.2 mg, 12.7%). LCMS calculated for C22H24BrN8O2 (M+H): 511.1; found: 511.1, 513.1. Example 73 7-bromo-9-pentyl-3-{2-[3-(2-thienylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 72. LCMS calculated for C20H22BrN8O2S (M+H): 517.1; found 517.1, 519.1. Example 74 7-bromo-9-pentyl-3-(2-{3-[4-(trifluoromethyl)benzyl]-1,2,4-oxadiazol-5-yl}ethyl)-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one Step A (1Z)-N′-hydroxy-2-[4-(trifluoromethyl)phenyl]ethanimidamide A suspension of [4-(trifluoromethyl)phenyl]acetonitrile (1.0 g, 5.4 mmoles), hydroxylamine hydrochloride (0.41 g, 5.9 mmoles) and NaHCO3 (0.50 g, 5.9 mmoles) in MeOH (15 ml) was refluxed for 4 hours. The reaction mixture was then concentrated to remove the solvent methanol. The residue was extracted with ethyl acetate. The combined organic layers were washed with brine and dried over Na2SO4 and concentrated to afford the desired product (1.0 g, 84.9%) as white solid. LCMS calculated for C9H10F3N2O (M+H): 219.1; found: 219.1. Step B 7-bromo-9-pentyl-3-(2-3-[4-(trifluoromethyl)benzyl]-1,2,4-oxadiazol-5-ylethyl)-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one 3-(7-Bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)propanoic acid (100 mg, 0.252 mmole) and CDI (44.9 mg, 0.277 mmole) were dissolved in anhydrous DMF (4 ml). After stirring the solution for 3 hours at room temperature, (1Z)-N′-hydroxy-2-[4-(trifluoromethyl)phenyl]ethanimidamide (60.4 mg, 0.277 mmole) was added and the solution heated at 90° C. for 20 hours, then at 110° C. for 4 hours. After evaporation of solvent, the residue was purified by preparative LC-MS to afford the desired product (6.4 mg, 4.4%) as white solid. LCMS calculated for C24H24BrF3N7O2 (M+H): 578.1; found 578.1, 580.1. Example 75 7-bromo-3-{2-[3-(4-fluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C22H22BrFN8O2 (M+H): 529.1; found: 529.1, 531.1. Example 76 7-bromo-9-pentyl-3-{2-[3-(4-methoxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C23H25BrN8O3 (M+H): 541.1; found 541.1, 543.1. Example 77 7-bromo-9-pentyl-3-{2-[3-(pyridine-4-ylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C21H22BrN9O2 (M+H): 512.1; found: 512.1, 514.1. Example 78 7-bromo-9-pentyl-3-(2-{3-[3-(trifluoromethyl)benzyl]-1,2,4-oxadiazol-5-yl}ethyl)-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C24H24BrF3N7O2 (M+H): 578.1; found 578.1, 580.1. Example 79 7-bromo-9-pentyl-3-(2-{3-[2-(trifluoromethyl)benzyl]-1,2,4-oxadiazol-5-yl}ethyl)-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C24H24BrF3N7O2 (M+H): 578.1; found 578.1, 580.1. Example 80 7-bromo-9-pentyl-3-{2-[3-(pyridine-3-ylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C21H22BrN9O2 (M+H): 512.1; found: 512.1, 514.1. Example 81 7-bromo-9-pentyl-3-{2-[3-(2-phenylethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. 1HNMR (400 MHz, d6-DMSO): δ 7.20 (m, 5H), 4.20 (t, J=7.4 Hz, 2H), 3.67 (t, J=7.4 Hz, 2H), 3.41 (t, J=7.4 Hz, 4H), 3.35 (br, 1H), 2.91 (s, 4H), 1.78 (m, 2H), 1.27 (m, 4H), 0.81 (m, 3H). LCMS calculated for C23H25BrN8O2 (M+H): 525.1; found: 525.1, 527.0. Example 82 7-bromo-9-pentyl-3-[2-(3-phenyl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C21H21BrN8O2 (M+H): 497.1; found: 497.1, 499.1. Example 83 7-bromo-3-{2-[3-(3-fluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C22H22BrFN8O2 (M+H): 529.1; found: 529.1, 531.1. Example 84 7-bromo-3-{2-[3-(4-chlorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C22H22BrClN8O2 (M+H): 545.1; found: 545.1, 547.1, 549.1. Example 85 3-[2-(3-benzyl-1,2,4-oxadiazol-5-yl)ethyl]-7-chloro-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 72. LCMS calculated for C22H23ClN8O2 (M+H): 467.2; found: 467.2. Example 86 7-bromo-3-{2-[3-(2-fluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. 1HNMR (400 MHz, d6-DMSO): δ 7.30 (m, 2H), 7.13 (m, 2H), 4.19 (t, J=7.5 Hz, 2H), 4.05 (s, 2H), 3.64 (t, J=7.5 Hz, 2H), 3.39 (t, J=7.5 Hz, 2H), 1.78 (m, 2H), 1.28 (m, 4H), 0.83 (m, 3H). LCMS calculated for C22H22BrFN8O2 (M+H): 529.1; found: 529.1, 531.1. Example 87 7-bromo-3-{2-[3-(2-methoxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C23H25BrN8O3 (M+H): 541.1; found 541.1, 543.1. Example 88 7-bromo-3-[2-(3-ethyl-1,2,4-oxadiazol-5-yl)ethyl]-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 72. LCMS calculated for C17H21BrN8O2 (M+H): 449.1; found 449.1. Example 89 7-bromo-3-{2-[3-(3-methoxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C23H25BrN8O3 (M+H): 541.1; found 541.1, 543.1. Example 90 7-bromo-3-{2-[3-(3-methylbenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C23H25BrN8O2 (M+H): 525.1; found 525.1, 527.1. Example 91 7-bromo-3-{2-[3-(2,4-difluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C22H21BrF2N8O2 (M+H): 547.1; found 547.1, 549.1. Example 92 7-bromo-3-{2-[3-(3,5-difluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C22H21BrF2N8O2 (M+H): 547.1; found 547.1, 549.1. Example 93 7-bromo-9-pentyl-3-{2-[3-(3-thienylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C20H22BrN8O2S (M+H): 517.1; found 517.1, 519.1. Example 94 7-bromo-9-pentyl-3-{2-[3-(1-phenylcyclopropyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-pyrrolo[3,2-d][1,2,4]triazolo[4,3-a]pyrimidin-5-one The title compound was prepared using procedures analogous to those described for Example 72. LCMS calculated for C24H25BrN8O2 (M+H): 537.1; found 537.1, 539.1. Example 95 7-bromo-9-pentyl-3-{2-[3-(pyridine-2-ylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C21H22BrN9O2 (M+H): 512.1; found: 512.1, 514.1. Example 96 3-[(2R)-2-(3-benzyl-1,2,4-oxadiazol-5-yl)propyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C23H25BrN8O2 (M+H): 525.1; found: 525.1, 527.1. Example 97 7-bromo-3-(2-{3-[(4-methyl-1,3-thiazol-2-yl)methyl]-1,2,4-oxadiazol-5-yl}ethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C20H23BrN9O2S (M+H): 532.1; found: 532.0, 534.0. Example 98 7-bromo-3-{2-[3-(2-methylbenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C23H26BrN8O2 (M+H): 525.1; found 525.0, 527.0. Example 99 7-bromo-3-(2-{3-[hydroxy(phenyl)methyl]-1,2,4-oxadiazol-5-yl}ethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C22H24BrN8O3 (M+H): 527.1; found 527.0, 529.0. Example 100 7-bromo-3-{2-[3-(2,5-difluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C22H22BrF2N8O2 (M+H): 547.1; found: 547.0, 547.0. Example 101 7-bromo-9-pentyl-3-{2-[3-(pyrimidin-5-ylmethyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. 1HNMR (400 MHz, d6-DMSO): δ 9.06 (s, 1H), 8.74 (s, 2H), 4.20 (t, J=7.6 Hz, 2H), 4.15 (s, 2H), 3.66 (t, J=7.6 Hz, 2H), 3.41 (t, J=7.6 Hz, 2H), 1.78 (m, 2H), 1.29 (m, 4H), 0.83 (m, 3H). LCMS calculated for C20H22BrN10O2 (M+H): 513.1; found: 513.1, 515.1. Example 102 7-bromo-9-butyl-3-{2-[3-(2-fluorobenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 74. LCMS calculated for C21H21BrFN8O2 (M+H): 515.1; found 515.0, 517.0. Example 103 3-[2-(3-benzyl-1,2,4-oxadiazol-5-yl)ethyl]-9-pentyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A methyl 3-(3-benzyl-1,2,4-oxadiazol-5-yl)propanoate Butanedioic acid, monomethyl ester (4.0 g, 30.3 mmole) and CDI (5.40 g, 33.3 mmole) were dissolved in anhydrous DMF (15 ml). After stirring the solution at room temperature for 3 hours, (1Z)-N′-hydroxy-2-phenylethanimidamide (5.0 g, 33.3 mmole) was added and the solution heated at 90° C. for 20 hours. After evaporation of solvent, the residue was dissovled in EtOAc. The organic phase was washed with water and brine, dried over Na2SO4. After filtration and evaporation of solvent, the residue was purified by flash chromatography on silica gel eluted with EtOAc/Hexane (25/75). The purification gave 5.2 g (69.7%) of product as light yellowish oil. LCMS calculated for C13H11N2O3 (M+H): 247.1; found 247.0. Step B 3-(3-benzyl-1,2,4-oxadiazol-5-yl)propanoic acid To a solution of methyl 3-(3-benzyl-1,2,4-oxadiazol-5-yl)propanoate (5.2 g, 21.1 mmole) in methanol (30 ml) was added 50 ml of 1N NaOH. The mixture was stirred at room temperature for 2 hours. The mixture was adjusted to PH=3-4 under ice bath, and extracted with EtOAc (3×). The combined organic phases were washed with water and brine, dried over Na2SO4 and concentrated to yield the desired product (4.8 g, 98%) as colorless oil. LCMS calculated for C12H13N2O3 (M+H): 233.1, found 233.0. Step C 3-(3-benzyl-1,2,4-oxadiazol-5-yl)-N-[(2E)-6-oxo-3-pentyl-8-(trifluoromethyl)-1,3,6,7-tetrahydro-2H-purin-2-ylidene]propanohydrazide The mixture of 3-(3-benzyl-1,2,4-oxadiazol-5-yl)propanoic acid (100.0 mg, 0.431 mmole), (2E)-3-pentyl-8-(trifluoromethyl)-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (144.1 mg, 0.474 mmole), BOP (209.5 mg, 0.474 mmole) and triethylamine (0.120 ml, 0.861 mmole). in DMF (4 ml) was stirred at room temperature overnight. The mixture was diluted with EtOAc (100 ml) and washed with water, then brine. The organic phase was dried over Na2SO4, filtrated and concentrated to give the desired product (220.1 mg, 98.6%) as yellowish oil. LCMS calculated for C23H26F3N8O3 (M+H): m/z=5192; found 519.2. Step D 3-[2-(3-benzyl-1,2,4-oxadiazol-5-yl)ethyl]-9-pentyl-7-(trifluoromethyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of 3-(3-benzyl-1,2,4-oxadiazol-5-yl)-N′-[(2E)-6-oxo-3-pentyl-8-(trifluoromethyl)-1,3,6,7-tetrahydro-2H-purin-2-ylidene]propanohydrazide (220.1 mg, 0.424 mmole) in toluene (20 ml) was refluxed for 5 hours. After evaporation of solvent, the residue was purified by preparative LCMS to yield the desired product (37.9 mg, 17.8%) as white solid. LCMS calculated for C23H24F3N8O2 (M+H): 501.2; found 501.1. Example 104 3-[2-(3-benzyl-1,2,4-oxadiazol-5-yl)ethyl]-7-cyclopropyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 103. LCMS calculated for C25H29N8O2 (M+H): 473.2; found: 473.1 Example 105 3-methyl-9-pentyl-7-[1-(trifluoromethyl)cyclopropyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 32. 1HNMR (400 MHz, d6-DMSO): δ 4.22 (t, J=7.03 Hz, 2H), 2.71 (s, 4H), 1.80 (m, 2H), 1.49 (s, 3H), 1.28 (m, 4H), 0.81 (m, 3H). LCMS calculated for C16H20F3N6O (M+H): 369.2; found: 269.1 Example 106 7-(2,2-difluorocyclopropyl)-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 32. LCMS calculated for C15H19F2N6O (M+H): 337.2; found: 337.1. Example 107 7-(1-hydroxycyclopropyl)-3-methyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 32. LCMS calculated for C15H21N6O2 (M+H): 317.2; found: 317.1. Example 108 7-bromo-9-pentyl-3-[2-(5-phenyl-1,3,4-oxadiazol-2-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A methyl 4-(2-benzoylhydrazino)-4-oxobutanoate The mixture of benzhydrazide (1.5 g, 11.0 mmol), butanedioic acid, monomethyl ester (2.0 g, 15 mmol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (5.4 g, 12 mmol), N,N-diisopropylethylamine (3.8 mL, 22 mmol) and 4-dimethylaminopyridine (0.87 g, 7.2 mmol) in DMF (30 mL) was stirred at room temperature overnight. The mixture was quenched with water and extracted with ethyl acetate three times. The combined organic layers were washed by brine, dried over sodium sulfate, filtered and concentrated. The crude residue was purified by flash column chromatography to yield the desired product (900 mg, 32.6%). LCMS calculated for C12H11N2O4 (M+H): 251.1; found: 251.1. Step B Methyl 3-(5-phenyl-1,3,4-oxadiazol-2-yl)propanoate Thionyl chloride (0.34 mL, 4.7 mmol) was added to the mixture of methyl 4-(2-benzoylhydrazino)-4-oxobutanoate (900 mg, 4 mmol), Pyridine (0.87 mL, 0.011 mol) in tetrahydrofuran (20 mL) at room temperature. After stirring for 3 hours, the reaction mixture was concentrated. The residue was mixed with toluene (20 mL) and refluxed overnight. The reaction was diluted with water and extracted with ethyl acetate three times. The combined organic layers were dried with sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by flash column chromatography to yield the desired product (600 mg, 72%). LCMS calculated for C12H13N2O3 (M+H): 233.1; found: 233.1. Step C 3-(5-phenyl-1,3,4-oxadiazol-2-yl)propanoic acid A mixture of methyl 3-(5-phenyl-1,3,4-oxadiazol-2-yl)propanoate (600 mg, 2.0 mmol) in 1 M of aqueous NaOH (10 mL) and Methanol (10 mL) was stirred at room temperature overnight. The reaction solution was adjusted to pH 5 and extracted with ethyl acetate three times. The combined organic layers were dried, filtered and concentrated to yield the desired product (0.50 g, 83%). LCMS calculated for C11H11N2O3 (M+H): 219.1; found 219.1. Step D N′-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]-3-(5-phenyl-1,3,4-oxadiazol-2-yl)propanohydrazide The mixture of 3-(5-phenyl-1,3,4-oxadiazol-2-yl)propanoic acid (500 mg, 20 mmol), (2E)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (480 mg, 0.0020 mol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (980 mg, 22 mmol), 4-dimethylaminopyridine (100 mg, 10 mmol), and N,N-diisopropylethylamine (0.73 mL, 42 mmol) in DMF (30 mL) was stirred at room temperature overnight. The mixture was quenched with water and extracted with ethyl acetate three times. The combined organic layers were washed by brine, dried over sodium sulfate, filtered and concentrated. The crude residue was purified by flash column chromatography to yield the desired product (485 mg, 48.5%). LCMS calculated for C21H21N8O3 (M+H): 437.2; found 437.2. Step E 9-pentyl-3-[2-(5-phenyl-1,3,4-oxadiazol-2-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of N′-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]-3-(5-phenyl-1,3,4-oxadiazol-2-yl)propanohydrazide (485 mg, 1.11 mmol) in toluene (50 mL) was heated to reflux overnight. The mixture was concentrated to yield the desired product (310 mg, 66.7%). LCMS calculated for C21H23N8O2 (M+H): 419.2; found 419.2. Step F 7-bromo-9-pentyl-3-[2-(5-phenyl-1,3,4-oxadiazol-2-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of 9-pentyl-3-[2-(5-phenyl-1,3,4-oxadiazol-2-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (53 mg, 0.13 mmol) and N-bromosuccinimide (34 mg, 0.19 mmol) in THF (20 mL) was stirred at 70° C. for 1 hour. The reaction mixture was concentrated and the residue was purified by preparative LCMS to give the desired product. LCMS calculated for C21H22BrN8O2 (M+H): 497.1; found: 497.1. Example 109 3-[2-(5-benzyl-1,3,4-oxadiazol-2-yl)ethyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 108. 1HNMR (300 MHz, CD3OD): δ 8.18 (d, J=7.2 Hz, 1H), 7.3 (m, 4H), 4.34 (m, 2H), 3.78 (m, 2H), 3.64 (m, 2H), 3.52 (m, 2H), 1.89 (m, 2H), 1.39 (m, 4H), 0.92 (m, 3H). LCMS calculated for C22H24BrN8O2 (M+H): 511.1; found: 511.1, 513.1. Example 110 N-[(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)methyl]benzamide Step A benzyl 2-oxo-2-[(2E)-2-(6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene)hydrazino]ethylcarbamate The mixture of (2E)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (0.50 g, 0.0021 mol), N-carbobenzyloxyglycine (0.49 g, 0.0023 mol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (1.0 g, 2.3 mmol) and triethylamine (0.59 mL, 0.0042 mol) in DMF (20 mL) was stirred at room temperature overnight. The reaction mixture was diluted with EtOAc and washed with water (4×) and brine (1×). The aqueous was extracted with EtOAc (2×). The combined organic layers were dried (MgSO4) and concentrated to give the desired product (1.30 g, 86%). LCMS calculated for C20H26N7O4 (M+H): 428.2; found 428.2. Step B benzyl [(5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)methyl]carbamate The solution of benzyl 2-oxo-2-[(2E)-2-(6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene)hydrazino]ethylcarbamate (0.60 g, 0.84 mmol) in toluene (30 mL) was refluxed overnight. M+H=410.1. The product was precipitated from the reaction mixture and filtered to give the desired product (300 mg, 87%). LCMS calculated for C20H24N7O3 (M+H): 410.2; found: 410.2. Step C 3-(aminomethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one hydrochloride To the solution of benzyl [(5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)methyl]carbamate (0.30 g, 0.73 mmol) in methanol (20 mL) and 1 mL of conc. HCl was added 110% Pd/C under N2. The mixture was shaken under 30 PSI H2 for 3 hours. The reaction mixture was filtered through celite and concentrated to yield the desired product (210 mg, 92%). LCMS calculated for C12H18N7O (M+H): 276.2; found: 276.2. Step D N-[(5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)methyl]benzamide The mixture of 3-(aminomethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one hydrochloride (160 mg, 0.51 mmol), [B] benzoic Acid (0.069 g, 0.56 mmol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (0.25 g, 0.56 mmol) and triethylamine (0.21 mL, 1.5 mmol) in DMF (10 mL) was stirred at room temperature overnight. The reaction mixture was purified by preparative LCMS to yield the desired product (150 mg, 77%). LCMS calculated for C19H22N7O2 (M+H): 380.2; found: 380.2. Step E N-[(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)methyl]benzamide To the solution of N-[(5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)methyl]benzamide (0.11 g, 0.28 mmol) in THF (10 mL) was added N-Bromosuccinimide (0.076 g, 0.42 mmol). The mixture was stirred at 70° C. for 1 hour. The reaction mixture was concentrated and purified by preparative LCMS. LCMS calculated for C19H21BrN7O2 (M+H): 458.1; found: 458.0, 460.0. Example 111 N-[(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)methyl]acetamide The title compound was prepared using procedures analogous to those described for Example 108. LCMS calculated for C14H19BrN7O2 (M+H): 396.1; found: 396.0, 398.0. Example 112 3-(1-benzylpiperidin-4-yl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 108. LCMS calculated for C23H27BrN7O2 (M+H): 512.1; found: 512.1, 514.1. Example 113 3-[3-(3-benzyl-1,2,4-oxadiazol-5-yl)propyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 72. 1HNMR (300 MHz, CD3OD): δ 7.24 (m, 5H), 4.31 (t, J=6.8 Hz, 2H), 3.97 (s, 2H), 3.40 (t, J=6.8 Hz, 2H), 3.03 (t, J=6.8 Hz, 2H), 2.33 (m, 2H), 1.88 (m, 2H), 1.40 (m, 4H), 0.92 (m, 3H). LCMS calculated for C23H26BrN8O2 (M+H): 525.1; found: 525.1, 527.1. Example 114 2-bromo-4-pentyl-1,4-dihydro-9H-[1,2,4]triazolo[1,5-a]purin-9-one Step A 2-(methylthio)-3-pentyl-3,7-dihydro-6H-purin-6-one To a solution of 3-pentyl-2-thioxo-1,2,3,7-tetrahydro-6H-purin-6-one (13.0 g, 54.6 mmol) in 2 M of sodium hydroxide in water (250 mL) was added dimethyl sulfate (6.2 mL, 66 mmol), and the reaction mixture was stirred at room temperature for 1 hour, then neutralized with acetic acid. The precipitate was collected by filtration and recrystallized from ethyl acetate-MeOH (1:1) to give the desired product (5.50 g, 40%). LCMS calculated for C11H17N4OS (M+H): 253.1; found: 253.1. Step B 2-amino-3-pentyl-3,7-dihydro-6H-purin-6-one 2-(Methylthio)-3-pentyl-3,7-dihydro-6H-purin-6-one (5.0 g, 0.020 mol) was mixed with 100 ml of 28% ammonia hydroxide in a seal tube. The mixture was stirred at 100° C. for 4 days. After cooling to room temperature, the solid was filtered and dried to yield the desired product (3.0 g, 68%). LCMS calculated for C10H16N5O (M+H): 222.1; found: 222.1. Step C 1-amino-2-imino-3-pentyl-1,2,3,7-tetrahydro-6H-purin-6-one A solution of 2-imino-3-pentyl-1,2,3,7-tetrahydro-6h-purin-6-one (750 mg, 3.39 mmol) and 18 m of hydrazine in water (30 ml) was stirred at 150° C. for 30 min on a microwave reactor. The reaction was diluted with water and extracted with ethyl acetate three times, dried with sodium sulfate, filtered, and concentrated in vacuo to yield the crude product for next step without further purification. LCMS calculated for C10H17N6O (M+H): 237.1; found: 237.2. Step D 4-pentyl-1,4-dihydro-9H-[1,2,4]triazolo[1,5-a]purin-9-one The mixture of 1-amino-2-imino-3-pentyl-1,2,3,7-tetrahydro-6H-purin-6-one (0.10 g, 0.4 mmol) and ethyl orthoformate (5 mL, 30 mmol) was stirred at 100° C. for 6 hours. The reaction mixture was concentrated and purified by preparative LCMS to yield the desired product (20 mg, 20%). LCMS calculated for C11H15N6O (M+H): 247.1; found: 247.1. Step E 2-bromo-4-pentyl-1,4-dihydro-9H-[1,2,4]triazolo[1,5-a]purin-9-one To the mixture of 4-pentyl-1,4-dihydro-9H-[1,2,4]triazolo[1,5-a]purin-9-one (19 mg, 0.077 mmol) in tetrahydrofuran (10 mL) was added N-bromosuccinimide (20 mg, 0.12 mol) at rt. The mixture was stirred at 70° C. for 1 hour. The mixture was concentrated and purified by preparative LCMS to yield the desired product (3.10 mg, 12.4%). LCMS calculated for C11H14BrN6O (M+H): 325.0; found: 325.0, 327.0. Example 115 3-methyl-9-pentyl-7-(1,3-thiazol-4-yl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 32. LCMS calculated for C15H18N7OS (M+H): 344.1; found: 344.1 Example 116 7-bromo-9-pentyl-3-[2-(3-pyrazin-2-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 72. 1HNMR (300 MHz, d6-DMSO): δ 8.78 (d, J=1.9 Hz, 1H), 8.36 (dd, J=1.9, 5.0 Hz, 1H), 7.62 (dd, J=1.9, 8.2 Hz, 1H), 4.21 (t, J=7.1 Hz, 2H), 3.77 (t, J=7.1 Hz, 2H), 3.56 (t, J=7.1 Hz, 2H), 1.79 (m, 2H), 1.29 (m, 4H), 0.83 (m, 3H). LCMS calculated for C19H19BrN10O2 (M+H): 499.1; found: 499.1 Example 117 7-bromo-9-pentyl-3-[2-(3-pyridin-3-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 72. 1HNMR (300 MHz, CD3OD): δ 9.27 (s, 1H), 8.75 (m, 2H), 4.33 (t, J=8.1 Hz, 2H), 3.92 (t, J=8.1 Hz, 2H), 3.64 (t, J=8.1 Hz, 2H), 1.89 (m, 2H), 1.39 (m, 4H), 0.90 (m, 3H). LCMS calculated for C20H20BrN9O2 (M+H): 498.1; found: 498.1 Example 118 7-bromo-9-pentyl-3-[2-(3-pyridin-2-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 72. 1HNMR (300 MHz, d6-DMSO): δ 8.68 (S, 1H), 7.95 (m, 2H), 7.53 (m, 2H), 4.15 (m, 2H), 3.72 (m, 2H), 3.50 (m, 2H), 1.74 (m, 2H), 1.24 (m, 4H), 0.78 (m, 3H). LCMS calculated for C20H20BrN9O2 (M+H): 498.1; found: 498.1 Example 119 7-bromo-9-pentyl-3-[2-(3-pyridin-4-yl-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for Example 72. 1HNMR (300 MHz, d6-DMSO): δ 8.77 (d, J=5.5 Hz, 2H), 7.89 (d, J=5.5 Hz, 2H), 4.20 (t, J=8.3 Hz, 2H), 3.77 (t, J=8.3 Hz, 2H), 3.56 (t, J=8.3 Hz, 2H), 1.78 (m, 2H), 1.28 (m, 4H), 0.82 (m, 3H). LCMS calculated for C20H20BrN9O2 (M+H): 498.1; found: 498.1 Example 120 7-bromo-9-pentyl-3-{2-[3-(2-thienyl)-1,2,4-oxadiazol-5-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 72. 1HNMR (300 MHz, d6-DMSO): δ 7.85 (dd, J=1.3, 5.0 Hz, 1H), 7.74 (dd, J=1.3, 4.0 Hz, 1H), 7.22 (dd, J=5.0, 4.0 Hz, 1H), 4.20 (t, J=6.8 Hz, 2H), 3.73 (t, J=6.8 Hz, 2H), 3.49 (t, J=6.8 Hz, 2H), 1.79 (m, 2H), 1.28 (m, 4H), 0.82 (m, 3H). LCMS calculated for C19H19BrN8O2S (M+H): 503.1; found: 503.1. Example 121 3-(1,3-benzodioxol-5-ylmethyl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 35. 1HNMR (400 MHz, CD3OD): δ 6.83 (s, 1H), 6.78 (dd, J=2.1, 7.5 Hz, 1H), 6.70 (dd, J=2.1, 7.5 Hz, 1H), 4.53 (s, 2H), 4.31 (m, 2H), 1.88 (m, 2H), 1.28 (m, 4H), 0.90 (m, 3H). LCMS calculated for C19H19BrN6O3 (M+H): 458.1; found: 459.1, 461.1. Example 122 7-bromo-9-pentyl-3-pyrimidin-5-yl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for Example 16. 1HNMR (300 MHz, d6-DMSO): δ 9.27 (s, 1H), 9.11 (s, 2H), 4.34 (t, J=6.9 Hz, 2H), 3.38 (br, 1H), 1.87 (m, 2H), 1.34 (m, 4H), 0.87 (m, 3H). LCMS calculated for C15H15BrN8O (M+H): 403.1; found: 403.1, 405.1. Example 123 7-bromo-9-pentyl-3-[3-(3-phenyl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A methyl 4-(3-phenyl-1,2,4-oxadiazol-5-yl)butanoate Pentanedioic acid, monomethyl ester (1.00 g, 6.84 mmole) and CDI (1.22 g, 7.53 mmole) were dissolved in anhydrous DMF (10 ml). After stirring at room temperature for 3 hours, (1Z)-N′-hydroxybenzenecarboximidamide (1.02 g, 7.53 mmole) was added and the solution heated at 90° C. for 20 h. After evaporation of solvent, the residue was diluted with ethyl acetate. The organic layer was washed with water and brine, dried over Na2SO4, filtered and concentrated to give the desired product (1.53 g, 91% yield). LCMS calculated for C13H15N2O3 (M+H): 247.1; found: 247.1. Step B 4-(3-phenyl-1,2,4-oxadiazol-5-yl)butanoic acid To a solution of methyl 3-(3-phenyl-1,2,4-oxadiazol-5-yl)butanoate (1.53 g, 6.21 mmole) in methanol (10 ml) was added 1N NaOH (10 mL). After stirring at room temperature for 2 hours, the reaction solution was acidified to pH=3-4 with 6N HCl under an ice bath and then extracted with ethyl acetate three times. The combined organic layers were washed with water and then brine, dried over Na2SO4, filtered and concentrated to give the desired product (1.44 g, 99% yield) as white solid. LCMS calculated for C12H13N2O3 (M+H): 233.1; found: 233.1. Step C N′-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]-4-(3-phenyl-1,2,4-oxadiazol-5-yl)butanohydrazide A mixture of 4-(3-phenyl-1,2,4-oxadiazol-5-yl)butanoic acid (1.44 g, 6.20 mmol), (2e)-3-pentyl-3,7-dihydro-1h-purine-2,6-dione 2-hydrazone (1.61 g, 6.82 mmol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (3.02 g, 6.82 mmol) and triethylamine (1.73 ml, 12.4 mmol) in DMF (30 ml) was stirred at room temperature overnight. The reaction was diluted with water and extracted with ethyl acetate (3×). The organic layer was washed with water and then brine, dried over Na2SO4, filtered and concentrated to give the desired product (2.78 g, 99% yield) as yellowish oil. LCMS calculated for C22H27N8O3 (M+H): 451.2; found: 451.1. Step D 9-pentyl-3-[3-(3-phenyl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The mixture of N′-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]-4-(3-phenyl-1,2,4-oxadiazol-5-yl)butanohydrazide (2.78 g, 6.17 mmol) in toluene (100 ml) was refluxed for 2 hours. After cooling to room temperature, the solid was filtered, washed with ethyl acetate/Hexane (1:9) and dried to give the desired product (1.97 g, 74% yield). LCMS calculated for C22H25N8O2 (M+H): 433.2; found: 433.1. Step E 7-bromo-9-pentyl-3-[3-(3-phenyl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To the solution of 9-pentyl-3-[3-(3-phenyl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (0.50 g, 1.16 mmole) in THF (125 ml) at room temperature was added N-bromosuccinimide (0.309 g, 1.73 mmole). The mixture was stirred at 70° C. for 1 h. The mixture was concentrated and purified by preparative LCMS to yield the desired product (122 mg, 21% yield). LCMS calculated for C22H24BrN8O2 (M+H): 511.1; found: 511.0. Example 124 7-bromo-9-pentyl-3-[3-(3-pyridin-2-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C21H22BrN9O2 (M+H): 511.1, 513.1; found: 511.1, 513.1. Example 125 7-bromo-9-pentyl-3-[3-(3-pyridin-3-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C21H22BrN9O2 (M+H): 511.1, 513.1; found: 511.1, 513.1. Example 126 7-bromo-9-pentyl-3-[3-(3-pyridin-4-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C21H22BrN9O2 (M+H): 511.1, 513.1; found: 511.1, 513.1. Example 127 7-bromo-9-pentyl-3-[3-(3-pyrazin-2-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C20H21BrN10O2 (M+H): 513.1, 515.1; found: 513.1, 515.1. Example 128 7-bromo-9-pentyl-3-{3-[3-(2-thienyl)-1,2,4-oxadiazol-5-yl]propyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C20H21BrN8O2S (M+H): 517.1, 519.1; found: 517.1, 519.1. Example 129 7-bromo-9-pentyl-3-{3-[3-(3-thienyl)-1,2,4-oxadiazol-5-yl]propyl}-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C20H21BrN8O2S (M+H): 517.1, 519.1; found: 517.1, 519.1. Example 130 7-bromo-9-pentyl-3-(3-{3-[3-(trifluoromethyl)phenyl]-1,2,4-oxadiazol-5-yl}propyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C23H22BrF3N8O2 (M+H): 579.1, 581.1; found: 579.1, 581.1. Example 131 7-bromo-3-{3-[3-(4-methoxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C23H25BrN8O3 (M+H): 541.1, 543.1; found: 541.1, 543.1. Example 132 7-bromo-3-{3-[3-(4-fluorophenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C22H22BrFN8O2 (M+H): 529.1, 531.1; found: 529.1, 531.1. Example 133 7-bromo-9-pentyl-3-[3-(3-pyrimidin-2-yl-1,2,4-oxadiazol-5-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C20H21BrN10O2 (M+H): 513.1, 515.1; found: 513.1, 515.1. Example 134 7-bromo-3-{3-[3-(2-methoxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C23H25BrN8O3 (M+H): 541.1, 543.1; found: 541.1, 543.1. Example 135 7-bromo-3-{3-[3-(3-methoxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C23H25BrN8O3 (M+H): 541.1, 543.1; found: 541.1, 543.1. Example 136 7-bromo-3-{3-[3-(4-ethynylphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C24H23BrN8O2 (M+H): 535.1, 537.1; found: 535.1, 537.1. Example 137 7-bromo-3-{3-[3-(1H-indol-5-yl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C24H24BrN9O2 (M+H): 550.1, 552.1; found: 550.1, 552.1. Example 138 7-bromo-3-{3-[3-(1H-indol-3-yl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C24H24BrN9O2 (M+H): 550.1, 552.1; found: 550.1, 552.1. Example 139 7-bromo-3-{3-[3-(6-methoxypyridin-3-yl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C22H24BrN9O3 (M+H): 542.1, 544.1; found: 542.1, 544.1. Example 140 3-{3-[3-(4-aminopyrimidin-5-yl)-1,2,4-oxadiazol-5-yl]propyl}-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C20H22BrN11O2 (M+H): 528.1, 530.1; found: 528.1, 530.1. Example 141 7-bromo-3-3-[3-(4-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]propyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a solution of 7-bromo-3-3-[3-(4-methoxyphenyl)-1,2,4-oxadiazol-5-yl]propyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (23.4 mg, 0.043 mmole) in CH2Cl2 (5 ml) at 0° C. was added a solution of BBr3 in CH2Cl2 (1 M, 0.43 ml, 0.43 mmole). The mixture was stirred at room temperature overnight. The reaction was quenched with H2O at 0° C. The reaction mixture was extracted with CH2Cl2 (3×). The combined organic layers were washed with water and then brine, dried over Na2SO4, filtered and concentrated to give the crude product, which was purified by preparative LCMS to yield the desired product (2.9 mg, 13% yield) as white solid. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.1; found: 527.0, 529.0. Example 142 7-bromo-3-3-[3-(2-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]propyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.1; found: 527.0, 529.0. Example 143 7-bromo-3-3-[3-(3-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]propyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.1; found: 527.0, 529.0. Example 144 7-bromo-3-{2-[3-(4-hydroxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.1; found: 527.0, 529.0. Example 145 7-bromo-3-{2-[3-(2-hydroxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.1; found: 527.0, 529.0. Example 146 7-bromo-3-{2-[3-(3-hydroxybenzyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.1; found: 527.0, 529.0. Example 147 7-bromo-9-pentyl-3-[3-(4-phenyl-1H-pyrazol-1-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A ethyl 4-(4-phenyl-1H-pyrazol-1-yl)butanoate The mixture of ethyl 4-bromobutyrate (0.400 g, 2.05 mmole), 4-phenyl-1H-pyrazole (0.296 g, 2.05 mmole) and K2CO3 (0.567 g, 4.10 mmole) in DMF (10 ml) was stirred at room temperature overnight. The reaction mixture was diluted with water (100 ml) and extracted with ethyl acetate (2×). The combined organic phases were washed with water and then brine, dried over Na2SO4, filtered and concentrated to give the crude product, which was purified by preparative to afford the desired product (73 mg, 52%) as colorless oil. LCMS calculated for C15H19N2O2 (M+H): 259; found: 259.1. Step B 4-(4-phenyl-1H-pyrazol-1-yl)butanoic acid A mixture of ethyl 4-(4-phenyl-1H-pyrazol-1-yl)butanoate (273 mg, 1.06 mmole) in methanol (5 ml) and 1N NaOH (5 mL) was stirred at room temperature for 2 hours. The reaction mixture was adjusted to be acidic (pH=3-4) with 6 N HCl with an ice bath and then extracted with EtOAc (3×). The combined organic phases were washed with water and brine, dried over Na2SO4, filtered and concentrated to give the desired product (190 mg, 78%). LCMS calculated for C13H15N2O2 (M+H): 231.1; found: 231.1. Step C N′-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]-4-(4-phenyl-1H-pyrazol-1-yl)butanohydrazide A mixture of 4-(4-phenyl-1H-pyrazol-1-yl)butanoic acid (190 mg, 0.825 mmol), (2E)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (195.0 mg, 0.825 mmol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (401 mg, 0.908 mmol) and triethyl amine (0.23 ml, 1.65 mmol) in DMF (10 ml) was stirred at room temperature overnight. The mixture was diluted with EtOAc and washed with water and then brine. The organic phase was dried over Na2SO4, filtered and concentrated to yield the desired product (369 mg, 99.7% yield) as yellowish oil. LCMS calculated for C23H29N8O2 (M+H): 449.2; found: 449.2. Step D 9-pentyl-3-[3-(4-phenyl-1H-pyrazol-1-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A mixture of N′-[(2E)-6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene]-4-(4-phenyl-1H-pyrazol-1-yl)butanohydrazide (369 mg, 0.823 mmols) in toluene (20 ml) was refluxed for 2 hours. After cooling to room temperature, the solid formed was filtered, washed with EtOAc/Hexane (1:9) and dried to give the desired product (234 mg, 66% yield) as off pink solid. LCMS calculated for C23H27N8O (M+H): 431.2; found: 431.1. Step E 7-bromo-9-pentyl-3-[3-(4-phenyl-1H-pyrazol-1-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a solution of 9-pentyl-3-[3-(4-phenyl-1H-pyrazol-1-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (234 mg, 0.543 mmol) in THF (45 ml) at room temperature was added N-bromosuccinimide (145 mg, 0.814 mmol). After stirring at 70° C. for 1 hour, the reaction mixture was concentrated and then purified by preparative LCMS to give the desired product (106 mg, 38%) as white solid. LCMS calculated for C23H26BrN8O (M+H): 509.1, 511.1; found: 509.0, 511.1. Example 148 7-bromo-9-pentyl-3-[3-(4-phenyl-1H-imidazol-1-yl)propyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 147. LCMS calculated for C23H26BrN8O (M+H): 509.1, 511.1; found: 509.0, 511.1. Example 149 7-bromo-3-3-[4-(5-fluoro-2-hydroxyphenyl)-1H-pyrazol-1-yl]propyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 147. LCMS calculated for C23H25BrFN8O2 (M+H): 543.1; found: 543.0, 545.0. Example 150 7-bromo-3-2-[5-(4-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one Step A 4,4-diethoxy-N-hydroxybutanimidamide A mixture of 4,4-diethoxybutanenitrile (5.0 g, 32 mmol), hydroxylamine hydrochloride (2.4 g, 35 mmol) and sodium bicarbonate (2.9 g, 35 mmol) in methanol (50 mL) was refluxed for 5 hours. After cooling to room temperature, the reaction mixture was concentrated and the residue was diluted with EtOAc and water. The water layer was extracted with EtOAc (2×). The combined organic layers were washed with water, dried over Na2SO4, filtered and concentrated to give the product, which was used next step without purification. 1HNMR (300 MHz, CD3Cl): δ 4.73 (br, 1H), 4.51 (t, J=5.5 Hz, 1H), 3.66 (m, 2H), 3.50 (m, 2H), 2.21 (t, J=8.2 Hz, 2H), 1.86 9m, 2H), 1.19 (t, J=8.2 Hz, 6H). Step B 3-(3,3-diethoxypropyl)-5-(4-methoxyphenyl)-1,2,4-oxadiazole A mixture of 4-methoxybenzoic acid (0.88 g, 5.78 mmol) and CDI (1.02 g, 6.31 mmol) in DMF (20 ml) was stirred at room temperature for 3 hours. 4-diethoxy-N-hydroxybutanimidamide (1.0 g, 5.26 mmol) was added to the above mixture and then heated at 100° C. overnight. After cooling to room temperature, the reaction mixture was diluted with water and extracted with EtOAc (3×). The combined organic layers was dried over Na2SO4, filtered, and concentrated in vacuo to yield the desired product LCMS calculated for C16H23N2O4 (M+H): 307.2; found: 307.2. Step C 3-[5-(4-methoxyphenyl)-, 2,4-oxadiazol-3-yl]propanal A mixture of 3-(3,3-diethoxypropyl)-5-(4-methoxyphenyl)-1,2,4-oxadiazole (1.0 g, 3.0 mmol) in 2N HCl (10 mL) and THF (10 mL) was stirred at room temperature overnight. The reaction mixture was extracted with EtOAc (3×). The organic layers were washed with water, dried over Na2SO4, filtered and concentrated to give the desired product. LCMS calculated for C12H13N2O3 (M+H): 233.1; found: 233.1. Step D 3-2-[5-(4-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one A mixture of 1H-purine-2,6-dione 2-hydrazone (680 mg, 2.88 mmol) and 3-[5-(4-methoxyphenyl)-1,2,4-oxadiazol-3-yl]propanal (900 mg, 3.88 mol) in ethanol (20 mL) was refluxed for 4 hours. The reaction mixture was concentrated and the residue was mixed with acetic acid (10 mL). The resulting mixture was refluxed for 3 hours. The reaction mixture was concentrated and then diluted with water and extracted with EtOAc (3×). The combined organic layers was dried over Na2SO4, filtered, concentrated and purified by preparative LCMS to give the desired product (830 mg, 64% yield). LCMS calculated for C22H25N8O3 (M+H): 449.2; found: 449.2. Step E 7-bromo-3-2-[5-(4-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a solution of 3-2-[5-(4-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (160 mg, 0.36 mol) in DMF (15 mL) at room temperature was added N-bromosuccinimide (110 mg, 0.61 mol). After stirring at 70° C. for 1 hour, the reaction mixture was concentrated and purified by preparative LCMS to provide the desired product. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.0; found: 527.0, 529.0. Example 151 7-bromo-3-2-[5-(4-hydroxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a solution of 7-bromo-3-2-[5-(4-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (190 mg, 0.36 mmol) in CH2Cl2 (12 mL) was added a solution of BBr3 in CH2Cl2 (1 M, 7.0 ml, 7.0 mmole) at room temperature. After stirring at room temperature overnight, the reaction mixture was concentrated and purified by preparative LCMS to give the desired product. LCMS calculated for C21H22BrN8O3 (M+H): 513.1, 515.1; found: 513.1, 515.1. Example 152 7-bromo-3-2-[5-(3-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 152. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.0; found: 527.0, 529.0. Example 153 7-bromo-3-2-[5-(3-hydroxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 151. LCMS calculated for C21H22BrN8O3 (M+H): 513.1, 515.1; found: 513.1, 515.1. Example 154 7-bromo-3-2-[5-(2-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 150. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.0; found: 527.0, 529.0. Example 155 7-bromo-3-2-[5-(2-hydroxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 151. LCMS calculated for C21H22BrN8O3 (M+H): 513.1, 515.1; found: 513.1, 515.1. Example 156 7-bromo-3-2-[5-(2-chloro-4-methoxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 150. LCMS calculated for C22H23BrClN8O3 (M+H): 561.1, 563.1; found: 561.1, 563.1. Example 157 7-bromo-3-2-[5-(2-chloro-4-hydroxyphenyl)-1,2,4-oxadiazol-3-yl]ethyl-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 151. LCMS calculated for C21H21BrClN8O3 (M+H): 547.1, 549.1; found: 547.0, 549.0. Example 158 7-bromo-9-pentyl-3-[2-(5-pyridin-4-yl-1,2,4-oxadiazol-3-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 150. LCMS calculated for C20H21BrN9O2 (M+H): 498.1, 500.1; found: 498.1, 500.1. Example 159 7-bromo-9-pentyl-3-[2-(5-pyridin-3-yl-1,2,4-oxadiazol-3-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 150. LCMS calculated for C20H21BrN9O2 (M+H): 498.1, 500.1; found: 498.1, 500.1. Example 160 7-bromo-9-pentyl-3-[2-(5-pyridin-2-yl-1,2,4-oxadiazol-3-yl)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate The title compound was prepared using procedures analogous to those described for example 150. LCMS calculated for C20H21BrN9O2 (M+H): 498.1, 500.1; found: 498.1, 500.1. Example 161 7-bromo-3-{2-[3-(4-methoxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 72. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.0; found: 527.0, 529.0. Example 162 7-bromo-3-{2-[3-(3-methoxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 72. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.0; found: 527.0, 529.0. Example 163 7-bromo-3-{2-[3-(2-methoxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 72. LCMS calculated for C22H24BrN8O3 (M+H): 527.1, 529.0; found: 527.0, 529.0. Example 164 7-bromo-3-{2-[3-(4-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C21H21BrN8O3 (M+H): 512.1, 514.1; found: 512.0, 514.0. Example 165 7-bromo-3-{2-[3-(3-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C21H21BrN8O3 (M+H): 512.1, 514.1; found: 512.0, 514.0. Example 166 7-bromo-3-{2-[3-(2-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C21H21BrN8O3 (M+H): 512.1, 514.1; found: 512.0, 514.0. Example 167 7-bromo-3-{2-[3-(2-chloro-4-methoxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 72. LCMS calculated for C22H23BrClN8O3 (M+H): 561.1, 563.1; found: 561.1, 563.1. Example 168 7-bromo-3-{2-[3-(2-chloro-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]ethyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C21H21BrClN8O3 (M+H): 547.1, 549.1; found: 547.0, 549.0. Example 169 3-[2-(5-benzyl-1,2,4-oxadiazol-3-yl)ethyl]-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 150. LCMS calculated for C22H23BrN8O2 (M+H): 511.1, 513.1; found: 511.0, 513.0. Example 170 7-bromo-3-{3-[3-(2-chloro-4-methoxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 123. LCMS calculated for C23H25BrClN8O3 (M+H): 575.1, 577.1; found: 575.1, 577.1. Example 171 7-bromo-3-{3-[3-(2-chloro-4-hydroxyphenyl)-1,2,4-oxadiazol-5-yl]propyl}-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 141. LCMS calculated for C22H23BrClN8O3 (M+H): 561.1, 563.1; found: 561.1, 563.1. Example 172 N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-4-methoxybenzamide Step A benzyl (3Z)-3-[(2E)-(6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene)hydrazono]propylcarbamate A mixture of (2E)-3-pentyl-3,7-dihydro-1H-purine-2,6-dione 2-hydrazone (2.3 g, 9.6 mmol) and benzyl (3-oxopropyl)carbamate (2.0 g, 9.6 mol) in ethanol (30 mL) was refluxed overnight. The reaction mixture was concentrated to give the product (4.0 g, 58% yield), which was used for next step without further purification. LCMS calculated for C21H25N7O3 (M+H): 426.2; found: 426.1. Step B benzyl [2-(5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]carbamate A mixture of benzyl (3Z)-3-[(2E)-(6-oxo-3-pentyl-1,3,6,7-tetrahydro-2H-purin-2-ylidene)hydrazono]propylcarbamate (4.0 g, 5.6 mol) in acetic acid (50 mLl) was refluxed in the air overnight. The mixture was concentrated and purified by preparative LCMS to give the desired product (1.3 g, 54% yield) as a white solid. LCMS calculated for C21H26N7O3 (M+H): 424.2; found: 424.2. Step C 3-(2-aminoethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a solution of benzyl [2-(5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]carbamate (0.52 g, 1.2 mmol) in methanol (50 mL) was added 10% Pd/C (100 mg). The reaction mixture was shaken in a hydrogenation reactor under 50 Psi H2 for 3 hours. The reaction mixture was filtered through a pad of celite. The filtrate was concentrated to give the desired product (320 mg, 90% yield). LCMS calculated for C13H20N7O (M+H): 290.2; found: 290.1. Step D 3-(2-aminoethyl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one To a mixture of 3-(2-aminoethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (310 mg, 1.1 mmol) in THF (50 mL), was added N-Bromosuccinimide (0.29 g, 1.6 mol). The mixture was stirred at 70° C. for 1 hour. The reaction mixture was concentrated. The solid was filtered and washed with EtOAc to yield the desired product (300 mg, 76% yield). LCMS calculated for C13H19BrN7O (M+H): 368.1, 370.1; found: 368.0, 370.0. Step E N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-4-methoxybenzamide A mixture of 3-(2-aminoethyl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (70 mg, 0.20 mmol), 4-methoxybenzoic acid (32 mg, 0.21 mmol), benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (92 mg, 0.21 mmol), and triethylamine (0.053 mL, 0.38 mmol) in DMF (5 mL) was stirred at room temperature overnight. The reaction mixture was diluted with water and acetonitrile and then purified by prep LCMS to give the desired product (70 mg, 73% yield). LCMS calculated for C21H25BrN7O3 (M+H): 502.1, 504.0; found: 502.0, 504.0. Example 173 N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]benzamide The title compound was prepared using procedures analogous to those described for example 172. LCMS calculated for C20H23BrN7O2 (M+H): 472.1; 474.1; found: 472.0, 474.0. Example 174 N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]isonicotinamide trifluoroacetate The title compound was prepared using procedures analogous to those described for example 172. LCMS calculated for C18H22BrN8O2 (M+H): 473.1; 475.1; found: 473.0, 475.0. Example 175 7-bromo-9-pentyl-3-[2-(pyrimidin-2-ylamino)ethyl]-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one trifluoroacetate A mixture of 3-(2-aminoethyl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (60 mg, 0.20 mmol), 2-chloropyrimidine (25 mg, 0.22 mmol) and triethylamine (0.045 mL, 0.32 mmol) in 1,4-Dioxane (10 mL) was refluxed overnight. The reaction mixture was concentrated, and the residue was purified by preparative LCMS to give the desired product. LCMS calculated for C17H21BrN9O: 446.1; found: 446.0, 448.0. Example 176 N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]nicotinamide trifluoroacetate The title compound was prepared using procedures analogous to those described for example 172. LCMS calculated for C18H22BrN8O2 (M+H): 473.1; 475.1; found: 473.0, 475.0. Example 177 N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]pyridine-2-carboxamide trifluoroacetate To a solution of 2-Pyridinecarboxylic acid (20 mg, 0.16 mmol) in DMF (5 mL) was added CDI (26 mg, 0.16 mmol). After stirring at room temperature for 2 hours, 3-(2-aminoethyl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (50 mg, 0.0001 mol) was added the above solution, and the resulting mixture was stirred at room temperature overnight. The reaction mixture was diluted with water and acetonitrile and then purified by preparative LCMS to give the desired product. LCMS calculated for C19H22BrN8O2 (M+H): 473.1, 475.1; found: 473.0, 475.0. Example 178 3-amino-N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]isonicotinamide trifluoroacetate The title compound was prepared using procedures analogous to those described for example 172. LCMS calculated for C19H23BrN9O2 (M+H): 488.1; 490.1; found: 488.0, 490.0. Example 179 N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-2-methylisonicotinamide trifluoroacetate The title compound was prepared using procedures analogous to those described for example 177. LCMS calculated for C20H24BrN8O2 (M+H): 487.1; 489.1; found: 487.0, 489.0. Example 180 N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-N′-phenylurea A mixture of 3-(2-aminoethyl)-7-bromo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one (62 mg, 0.17 mmol) and phenyl isocyanate (0.018 mL, 0.16 mmol) in DMF (5 mL) was stirred at room temperature overnight. The reaction mixture was diluted with water and acetonitrile and then purified by preparative LCMS to give the desired product (about 80% conversion). LCMS calculated for C20H24BrN8O2 (M+H): 487.1; 489.1, found: 487.0, 489.0. Example 181 N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-4-hydroxybenzamide To a solution of N-[2-(7-bromo-5-oxo-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-3-yl)ethyl]-4-methoxybenzamide (63.0 mg, 0.125 mmol) in CH2Cl2 (5 mL) at 0° C. was added a solution of Boron tribromide in CH2Cl2 (1.0 M, 1.3 mL, 1.3 mmol). The mixture was stirred at room temperature overnight. The reaction mixture was quenched with water and then concentrated and purified by preparative LCMS to give the desired product. LCMS calculated for C20H23BrN7O3 (M+H): m/z=488.1, 490.1; found: 488.0, 489.9. Example 182 3-methyl-7-(pentafluoroethyl)-9-pentyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 1. LCMS calculated for C14H16F5N6O (M+H): 379.1; found: 379.1. Example 183 Preparation of 7-bromo-3-methyl-9-(4,4,4-trifluorobutyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 5. LCMS calculated for C11H11BrF3N6O (M+H): 379.0, 381.0.0; found: 379.0, 381.0. Example 184 Preparation of 7-bromo-3-methyl-9-(5,5,5-trifluoropentyl)-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 5. LCMS calculated for C12H13BrF3N6O (M+H): 393.0, 395.0; found: 393.0, 395.0. Example 185 Preparation of 7-bromo-9-(4-fluorobutyl)-3-methyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 5. LCMS calculated for C11H13BrFN6O (M+H): 343.0; found: 343.0. Example 186 Preparation of 7-bromo-9-(4-fluoropentyl)-3-methyl-6,9-dihydro-5H-[1,2,4]triazolo[4,3-a]purin-5-one The title compound was prepared using procedures analogous to those described for example 5. LCMS calculated for C12H15BrFN6O (M+H): 357.0, 359.0; found: 357.0, 359.0. Example A GTPγS Recruitment Assay Membranes were prepared from HEK293 cells transiently transfected with human HM74a and Gα0 protein. Assays were performed in 384-well format in a volume of 50 μL per assay point. Serial dilutions of compounds were prepared in the assay buffer (20 mM HEPES pH. 7.4, 100 mM NaCl, 10 mM MgCl2, 10 mg/L saponin and 10 μM GDP) and mixed with membranes (2 μg per assay point) and 35S GTPγS (Amersham, 0.3 nM) in the assay buffer. The mixtures were incubated at room temperature for 30 min and wheat germ agglutinin SPA beads (Amersham) (0.2 mg per assay point) in the assay buffer were added. After 30 min incubation with agitation, plates were centrifuged at 1500 g for 5 min and bound 35S GTPγS was determined by counting on a TopCount scintillation counter. An active compound according to this assay has an EC50 of about 50 μM or less. In some embodiments, the compounds of the present invention have an EC50 of less than about 50 μM, less than about 40 μM, less than about 30 μM, less than about 20 μM, less than about 10 μM, less than about 5 μM, less than about 1 μM, less than about 500 nM, less than 300 nM, or less than about 200 nM. For example, the compound of Example 1 has an EC50 of 80 nM in this assay. Example B Nicotinic Acid Displacement Assay Membranes were prepared from HEK293 cells transiently transfected with the human HM74a and Gα0 protein. Wheat germ agglutinin SPA beads (Amersham) were weighed and suspended in the assay buffer (50 mM Tris-HCl, pH. 7.5, 1 mM MgCl2 and 0.02% CHAPS). The beads were mixed with membrane (75 μg membrane/mg beads) at room temperature for 1 hr. The beads were spun down and washed once with buffer and then resuspended in buffer at 5 mg beads/ml. 20 nM of 3H nicotinic acid was added to the beads and then mixed with compounds at (total vol. of 50 μL). Nonspecific binding was determined by the inclusion of 100 μM nicotinic acid. The binding mixtures were incubated at room temperature for overnight with agitation. Plates were centrifuged at 1500 g for 5 min and bound 3H nicotinic acid was determined by counting on a TopCount scintillation counter. An active compound according to this assay has an IC50 of about 50 μM or less. In some embodiments, the compounds of the present invention have an IC50 of less than about 50 μM, less than about 40 μM, less than about 30 μM, less than about 20 μM, less than about 10 μM, less than about 5 μM, less than about 1 μM, less than about 500 nM, less than 300 nM, or less than about 200 nM. Example C FLIPR Assay HEK293e cells transfected with human HM74a and Gα16 DNA were seeded the day before the assay at 50,000 cells/well in 384-well plates. Cells were washed once with 1×HBSS and incubated with FLIPR Calcium 3 (Molecular Devices) dye in 1×HBSS buffer containing 3 mM probenecid at 37° C. and 5% CO2 for 60 min. Compounds were added to the cell plate and fluorescence changes due to Gα16-mediated intracellular calcium response were measured. An active compound according to this assay has an EC50 of about 50 μM or less. In some embodiments, the compounds of the present invention have an EC50 of less than about 50 μM, less than about 40 μM, less than about 30 μM, less than about 20 μM, less than about 10 μM, less than about 5 μM, less than about 1 μM, less than about 500 nM, less than 300 nM, or less than about 200 nM. Example D cAMP Assay CHO cells stably transfected with human HM74a were seeded at 7,500 cells/well in a 96-well plate in HAMS F12 medium with 10% FBS. The plate was incubated overnight at 37° C. and 5% CO2. The test compounds were prepared in a stimulation buffer containing 1×HANKS, 20 mM HEPES, 5 μM forskolin, and 0.25 mM IBMX. The media from the cell plate was removed before adding 30 μL of the test compounds. After 30 minute incubation at 37° C. and 5% CO2, the cAMP level was assayed using HitHunter cAMP XS assay kit (DiscoverX, CA). IC50 determinations were based on compound inhibition relative to DMSO controls. An active compound according to this assay has an IC50 of about 100 μM or less. In some embodiments, the compounds of the present invention have an IC50 of less than about 100 μM, less than about 80 μM, less than about 60 μM, less than about 40 μM, less than about 30 μM, less than about 20 μM, less than about 10 μM, less than about 5 μM, less than about 1 μM, less than about 500 nM, less than 300 nM, or less than about 200 nM. For example, the compound of Example 1 has an IC50 of 20 nM in this assay. Example E Adipocyte Lipolysis Assay Preadipocytes purchased from Zen Bio were plated at 8.7×104 cells/well in 96-well plates, differentiated for 14 days and mature adipocytes assayed during days 15 through 21. Adipocyte maturation is assessed by the presence of rounded cells with large lipid droplets in the cytoplasm. Following maturation, cells were washed and incubated overnight with IBMX (100 μM) and various concentrations of compound diluted in assay buffer containing a final DMSO concentration of 0.1%. After overnight culture, the glycerol concentration in the supernatants was determined with the Lipolysis Assay Kit purchased from Zen-Bio. Absorbance at 540 nm is directly proportional to the glycerol concentration in the sample. IC50 determinations were based on compound inhibition relative to DMSO controls. An active compound according to this assay has an IC50 of about 10 μM or less. In some embodiments, the compounds of the present invention have an IC50 of less than about 10 μM, less than about 5 μM, less than about 2 μM, less than about 1 μM, less than about 500 nM, less than 300 nM, less than 200 nM, less than 100 nM, or less than about 50 nM. For example, the compound of Example 77 has an IC50 of 37 nM in this assay. Various modifications of the invention, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference, including all patent, patent applications, and publications, cited in the present application is incorporated herein by reference in its entirety.
|
A
|
A61
|
A61K
|
314
|
95
|
|||
10580223
|
US20070169526A1-20070726
|
Biological fertilizer
|
ACCEPTED
|
20070711
|
20070726
|
[]
|
C05F1108
|
["C05F1108"]
|
7674310
|
20070223
|
20100309
|
071
|
008000
|
63662.0
|
LANGEL
|
WAYNE
|
[{"inventor_name_last": "Van Der Weide", "inventor_name_first": "Willibrordus", "inventor_city": "Strazske", "inventor_state": "", "inventor_country": "SK"}]
|
The present invention relates to a method for the preparation of a biological fertilizer comprising subjecting whey to a first fermentation step and the addition of a carrier material to the fermented whey and a biological fertilizer obtainable by the method. The biological fertilizer can be used as a replacement of the present artificial fertilizers thereby reducing many of the environmental problems associated with these artificial fertilizers. In addition, the biological fertilizer according to the present invention can be used in the field of biological agriculture for which, until the present biological fertilizer, no fertilizers were available.
|
1. Method for the preparation of a biological fertilizer comprising subjecting whey to a first fermentation step and the addition of a carrier material to the fermented whey. 2. Method according to claim 1, wherein the ratio fermented whey: carrier material is between 10 and 15. 3. Method according to claim 1, further comprising, prior to and/or during the first fermentation of the whey, the inoculation of the whey with a culture of microorganisms. 4. Method according to claim 1, wherein the first fermentation is performed a pH between 5 and 7, preferably at a pH between 4 and 4.5. 5. Method according to claim 1, further comprising, prior to the addition of the carrier material, filtration of the fermented whey. 6. Method according to claim 1, further comprising, after the addition of the carrier material, a second fermentation of step. 7. Method according to claim 1, further comprising the addition of lime. 8. Method according to claim 1, wherein the carrier material is a gum resin-poor carrier material. 9. Method according to claim 1, wherein the carrier material is a cellulose-rich carrier material. 10. Method according to claim 1, wherein the carrier material is selected from the group consisting of saw dust, beech saw dust, oak saw dust, dried nettle, and combinations thereof. 11. Method according to claim 1, further comprising the addition of trace elements, nutrients, minerals, growth hormones, stabilizers, organic compounds, and/or antibiotics. 12. Method according to claim 1 wherein the biological fertilizer is in a form selected from the group consisting of a powder, granules, a suspension, a dispersion, fibrous matter, a solution, a mixture, and combinations thereof. 13. Biological fertilizer obtainable by a method according to claim 1. 14. Fermented whey for the preparation of a biological fertilizer according to claim 13. 15. Composition for biologically fertilizing soil comprising a biological fertilizer according to claim 13. 16. Use of a biological fertilizer according to claim 13 for fertilization of a substrate for plant growth. 17. Use according to claim 16, wherein the substrate for plant growth is chosen from the group consisting of soil, vermiculite, glass fibers, rockwool, and aquaculture. 18. Use of a biological fertilizer according to claim 13 for improvement of soil composition and/or soil structure. 19. Method for fertilizing soil comprising: application of a biological fertilizer according to claim 13, onto and/or into soil. 20. Use of a composition according to claim 15 for fertilization of a substrate for plant growth. 21. Use of a composition according to claim 15 for improvement of soil composition and/or soil structure. 22. Method for fertilizing soil comprising: application of a composition according to claim 15 onto and/or into soil.
|
The present invention relates to methods for preparation of a biological fertilizer and a biological fertilizer obtainable by said method. The present invention further relates to a composition for fertilizing soil comprising said biological fertilizer, and the use of said biological fertilizer or said composition for fertilizing a substrate for plant growth. In addition, the present invention relates to a method for fertilizing soil. A sustainable form of agriculture, i.e., one which does not simply exploit the inherited fertility of agricultural soils, is based on the premise that plant nutrients which are removed with the harvested crops will be replaced. It is the regular supply of sufficient quantities of plant nutrients which has, over the past 100 years, maintained and even improved the fertility of farmers fields in Europe. Combined with advances in plant and animal breeding, plant protection, farm mechanization and land management, plant nutrition has been responsible for an increase in European farm output in recent years, in spite of a reduction in the total agricultural area. Plant nutrients are available from four different sources: 1) soil itself, 2) livestock, municipal and industrial wastes, 3) biological nitrogen fixation, and 4) mineral fertilizers, also designated as artificial fertilizers. Mineral fertilizers allow farmers to supplement plant nutrients, like trace elements, minerals, nitrogen, carbon, etc. and thus match the supply of nutrients with the needs of the crops. They are, in fact, the only nutrients which can be tailored to meet the crops' exact requirements. Providing guaranteed contents and the possibility of application as and when required. Mineral fertilizers are cost-effective means of achieving sustainable crop production and improvements in the quality of food and fodder. There is, at present, no alternative to mineral fertilizers on a regional or global scale if food supply is to be ensured. A major drawback of mineral fertilizers is the ineffective use of the fertilizer due to the release pattern of the plant nutrients from the mineral fertilizer into the soil. Upon application to soil, the nutrients present in the mineral fertilizers are usually “burst” released, i.e., all nutrients are released into the soil in a relatively short period of time. Since during plant growth, which requires usually several months, the concentration of nutrients transiently decreases, due to, for example, wash out or degradation, a relatively large amount of nutrients has to be used to ensure sufficient plant nutrient concentrations during the entire growth period. Thus a relatively large portion of mineral fertilizer supplemented is needed to compensate for losses occurring during the growth period and not for the intended nutrient supplementation of the growing plants. In addition, a relatively large portion of plant nutrients is not used by the growing plants. As a consequence,, eventually the not-used plant nutrients are introduced into the environment, by, for example, wash out. Wash out is the washing out or away of nutrients in soil by for example rain, freshet, etc. This wash out of plant nutrients can cause causing severe environmental problems like oxygen depletion in water by algae growth, destruction of epitopes by “unnatural” nutrient supply, disruption of the natural balance between species like an abnormal nettle growth, and a general decrease in the number of species, both plant an animal, present in an epitope. Therefore, it is a goal of the present invention to provide a cost-effective fertilizer which more effectively supplements nutrients to growing plants and thus reduces the amount of fertilizer needed and which, in addition, reduces the amount of plant nutrients introduced into the environment in order to minimalize or even eliminate environmental problems associated with this introduction. Because of the latter, such fertilizers are designated biological friendly or biological fertilizers as opposed to the present mineral (artificial) fertilizers. According to the present invention, this goal is achieved by providing a method for the preparation of a biological fertilizer comprising a fermentation of whey and the addition of a carrier material to the fermented whey. Whey is the watery part of milk that is separated from the coagulable part or curd, especially in the process of making cheese, and that is rich in lactose, minerals, and vitamins, and contains lactalbumin and traces of fat. At present, whey is considered a waste product of the cheese making industry and is usually discarded, thus providing a cost-effective starting material for a fertilizer. In addition, since whey is a “natural” product, i.e., a product that has undergone minimal processing and contains no preservatives or artificial additives, when the carrier material used is also a “natural” product, the fertilizer based on whey as starting material does not introduce these possible toxic or harmful preservatives and/or additives into the environment in contrast to the chemically synthesized mineral (artificial) fertilizers. This allows for the use of the biological fertilizer according to the invention by biological farmers, i.e., farmers which from a principal point of view do not use any “non-natural” products like mineral fertilizers, herbicides, or pesticides. Until now, no other fertilizers were available to these farmers severely limiting crop yields. According to the invention, the whey is fermented in a first fermentation step, for example during 2 days at room temperature under stirring, although any fermentation protocol can be used like fermentation at elevated temperatures, fermentation in an automated fermentation device, etc. The carrier material according to the invention, being preferably obtained from a “natural” source and in addition preferably in solid form, can be used to 1) provide a possible additional carbon source, 2) allow for improved transport and handling characteristics of the biological fertilizer, and 3) prevent wash out of the fermented whey after application. The fermented whey in combination with the carrier material provides a fertilizer which supplies nutrients to soil in a “sustained” or “continued” release pattern, i.e., a relatively constant release of nutrients during a relatively long period, probably due to the postfermentation of the fertilizer by soil microorganisms after application. A “sustained” release pattern requires less fertilizer as compared to a “burst” release pattern of (artificial) mineral fertilizers to achieve the desired nutrient concentration in soil since less compensation for an inevitable decrease in nutrient concentration is needed, thereby providing a more effective use of the biological fertilizer according to the invention compared with the (artificial) mineral fertilizers. In addition, since less fertilizer is needed for compensation, also less fertilizer is introduced into the environment, eliminating or reducing the environmental problems associated with this introduction. Preferably, the ratios between the fermented whey and the carrier material in the biological fertilizer according to the invention are between 10 to 15, like 10, 11, 12, 13, 14, or 15 (whey:carrier). Using these ratios, sufficiently texture is provided by the carrier material while optimally the benefits of fermented whey are maintained. According to one embodiment of the present invention, the whey, prior to and/or during the fermentation, is inoculated with a culture of microorganisms, comprising either a single microorganism or a mixture of organisms. By adding a specific microorganism culture, the first fermentation process can be performed faster and/or a better control of the process is achieved. In addition, the characteristics of the fermented whey can be influenced depending on the microorganism of choice like the nitrogen and/or carbon content. The fermentation of the whey is preferably carried out at pH 5 to 7, like pH 5, 5.5, 6, 6.5, or 7, more preferable at pH 4 to 4, 5, like pH 4, 4.1, 4.2, 4.3, 4.4 or 4.5, since at these pH's optimal fermentation is achieved. In a second embodiment of the present invention, prior to the addition of carrier material, the fermented whey is filtrated to separate the microbial biomass. Preferably, the principle of gravity feeding is used in the larger time scale. This allows for a low cost filtration step. According to a third embodiment of the present invention, after addition of the carrier material, a second fermentation of the product obtained is performed. This second fermentation further improves the availability of nutrients in the biological carrier. According to yet another embodiment of the present invention, lime is added to the biological fertilizer. In addition to improvement of the texture of the biological fertilizer, lime adds an addition calcium source to the biological fertilizer. Because of the negative influence of gum resin on the optional second fermentation step, and on the possible postfermentation process, the carrier material according to the invention preferably is a gum resin-poor carrier material. In addition, the accumulation of biomass in the fermentation process(es) can further be optimized by using a carrier material which is cellulose-rich. Specific examples of the carrier material according to the present invention are saw dust, beech saw dust, oak saw dust, dried nettle, etc. In order to meet specific requirements, and depending on the intended use, additives can be added to the biological fertilizer like trace elements, nutrients, minerals, growth hormones, stabilizers, organic compounds, antibiotics, etc. Preferably, the biological fertilizer according to the present invention is in the form of a powder, granules, a suspension, a dispersion, fibrous matter, a solution, a mixture, or combinations thereof. The biological fertilizer can be used in a composition comprising the biological fertilizer and any substances which are normally used in the field As already outlined above, the biological fertilizer according to the present invention is especially suited to be used for fertilization of a substrate for plant growth because of the “sustained” release pattern. Examples of suitable substrates are soil, vermiculite, glass fibers, rockwool, and/or aquaculture. According to another embodiment of the present invention, the biological fertilizer is used in a method for fertilizing soil comprising: application of a biological fertilizer or a composition according to the present invention onto and/or into soil. It was surprisingly found that not only nutrients are effectively supplied to soil but also soil composition and/or soil structure are improved. One possible mechanism for the observed improvement can be the addition of microorganisms to soil. The microorganisms enhance flora and fauna resulting in an improved resistance against diseases, more worms, an improved digestion of other organic materials, etc., The present invention will further be illustrated in the following examples. These examples should not be construed as limiting. EXAMPLE Preparation of a Biological Fertilizer According to the Present Invention The biological fertilizer according to the invention was prepared by subjecting whey, obtained from a cheese production facility, to a first fermentation step. The whey was stirred at room temperature during two days to incorporate the nutrients in the whey like Ca, K, N, C etc, into the forming biomass. After two days, the product obtained in the first fermentation step was filtered by gravitation filtration in order to increase the dry material content of the preparation. After discarding the liquid phase, wood dust was added to the material remaining on the filter and the combined material was allowed to ferment in a second fermentation step at room temperature. The percentage of elements was measured and the results are shown in table 1 TABLE 1 element analysis of the biological fertilizer according to the present invention. other Element C O H N P K Ca S minerals percentage 34 31 5 8 2 1 3 3 180
|
C
|
C05
|
C05F
|
11
|
08
|
|||||
11855054
|
US20080188256A1-20080807
|
POWER ALLOCATION IN A WIRELESS COMMUNICATION SYSTEM
|
ACCEPTED
|
20080723
|
20080807
|
[]
|
H04B7005
|
["H04B7005"]
|
7826863
|
20070913
|
20101102
|
455
|
522000
|
96313.0
|
SAFAIPOUR
|
BOBBAK
|
[{"inventor_name_last": "Wu", "inventor_name_first": "Xinzhou", "inventor_city": "Monmouth Junction", "inventor_state": "NJ", "inventor_country": "US"}, {"inventor_name_last": "Das", "inventor_name_first": "Arnab", "inventor_city": "Summit", "inventor_state": "NJ", "inventor_country": "US"}, {"inventor_name_last": "Li", "inventor_name_first": "Junyi", "inventor_city": "Bedminster", "inventor_state": "NJ", "inventor_country": "US"}]
|
Systems and methodologies are described that facilitate allocating power levels in a wireless communication network. A metric based upon spectral efficiency can be employed in connection with optimizing power allocation. Further, power for transmitters to utilize can be assigned as a function of time. Moreover, a single sub-carrier network and/or a multiple sub-carrier networks can leverage one or more power allocation schemes.
|
1. A method that facilitates operating a communication network including a first wireless communication base station that includes a first sector, comprising: transmitting on a first channel at a first power level from the first sector during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth; and transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. 2. The method of claim 1, further comprising: receiving a channel quality report from a mobile device; scheduling the first channel as a function of the channel quality report; and transmitting on the first channel to the mobile device. 3. The method of claim 1, wherein the first wireless communication base station includes a second sector, the method further comprising: transmitting on a second channel at a third power level from the second sector during the first time period based on a second predetermined pattern, the second channel including a second frequency bandwidth, the first frequency bandwidth and second frequency bandwidth having at least 50% frequency bandwidth in common; and transmitting on the second channel at a fourth power level from the second sector during the second time period based on the second predetermined pattern, the fourth power level is at least 0.5 dB different from the third power level. 4. The method of claim 3, wherein the first power level is within 0.5 dB of the third power level, and the second power level is within 0.5 dB of the fourth power level. 5. The method of claim 3, wherein the first and the second predetermined patterns are substantially similar. 6. The method of claim 1, wherein the communication network includes a second wireless communication base station that includes a second sector, the method further comprising: transmitting on a second channel at a third power level from the second sector during the first time period based on a second predetermined pattern, the second channel including a second frequency bandwidth, the first frequency bandwidth and second frequency bandwidth having at least 50% frequency bandwidth in common; and transmitting on the second channel at a fourth power level from the second sector during the second time period based on the second predetermined pattern, the fourth power level is at least 0.5 dB different from the third power level. 7. The method of claim 6, wherein the first power level is at least 0.5 dB greater than the third power level, and the second power level is at least 0.5 dB less than the fourth power level. 8. The method of claim 6, wherein the first and the second predetermined patterns are periodical with dissimilar periods. 9. The method of claim 6, wherein the first and the second predetermined patterns are periodical with substantially similar periods and differing phases. 10. A wireless communications apparatus, comprising: a memory that retains instructions related to transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern and transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level; and a processor, coupled to the memory, configured to execute the instructions retained in the memory. 11. The wireless communications apparatus of claim 10, wherein the memory further retains instructions for obtaining a channel quality report from a mobile device, scheduling the first channel as a function of the channel quality report, and transmitting on the first channel to the mobile device. 12. The wireless communications apparatus of claim 10, wherein the memory further retains instructions related to transmitting on a second channel at a third power level from a second sector during the first time period based on a second predetermined pattern and transmitting on the second channel at a fourth power level from the second sector during the second time period based on the second predetermined pattern, wherein the second channel includes a second frequency bandwidth, the first frequency bandwidth and the second frequency bandwidth having at least 50% frequency bandwidth in common, and the fourth power level is at least 0.5 dB different from the third power level. 13. The wireless communications apparatus of claim 12, wherein a first wireless communications base station includes the first sector and the second sector. 14. The wireless communications apparatus of claim 12, wherein a first wireless communications base station includes the first sector and a second wireless communications base station includes the second sector. 15. The wireless communications apparatus of claim 12, wherein the first and the second predetermined patterns are substantially similar. 16. The wireless communications apparatus of claim 12, wherein the first and the second predetermined patterns are periodical with disparate periods. 17. The wireless communications apparatus of claim 12, wherein the first and the second predetermined patterns are periodical with substantially similar periods and dissimilar phases. 18. A wireless communications apparatus that enables communicating with allocated power levels, comprising: means for transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth; and means for transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. 19. The wireless communications apparatus of claim 18, further comprising: means for obtaining a channel quality report from a mobile device; means for scheduling the first channel as a function of the channel quality report; and means for transmitting on the first channel to the mobile device. 20. The wireless communications apparatus of claim 18, further comprising: means for transmitting on a second channel at a third power level from a second sector during the first time period based on a second predetermined pattern, the second channel including a second frequency bandwidth, the first frequency bandwidth and the second frequency bandwidth having at least 50% frequency bandwidth in common; and means for transmitting on the second channel at a fourth power level from the second sector during the second time period based on the second predetermined pattern, the fourth power level is at least 0.5 dB different from the third power level. 21. The wireless communications apparatus of claim 20, wherein the first and the second predetermined patterns are periodical and have at least one of disparate periods and disparate phases. 22. A machine-readable medium having stored thereon machine-executable instructions for: transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth; and transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. 23. The machine-readable medium of claim 22, the machine-executable instructions further comprise: receiving a channel quality report from a mobile device; scheduling the first channel as a function of the channel quality report; and transmitting on the first channel to the mobile device. 24. The machine-readable medium of claim 22, the machine-executable instructions further comprise: transmitting on a second channel at a third power level from a second sector during the first time period based on a second predetermined pattern, the second channel including a second frequency bandwidth, the first frequency bandwidth and the second frequency bandwidth having at least 50% frequency bandwidth in common; and transmitting on the second channel at a fourth power level from the second sector during the second time period based on the second predetermined pattern, the fourth power level is at least 0.5 dB different from the third power level, the first predetermined pattern and the second predetermined pattern are periodical and have at least one of disparate periods and disparate phases. 25. In a wireless communications system, an apparatus comprising: a processor configured to: transmit on a first channel at a first power level during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth; and transmit on the first channel at a second power level during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level.
|
<SOH> BACKGROUND <EOH>I. Field The following description relates generally to wireless communications, and more particularly to allocating power for transmitters in single-carrier or multi-carrier wireless communication systems. II. Background Wireless communication systems are widely deployed to provide various types of communication; for instance, voice and/or data can be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources. For instance, a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others. Common wireless communication systems employ one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast and/or unicast services, wherein a data stream can be a stream of data that can be of independent reception interest to a wireless terminal. A wireless terminal within the coverage area of such base station can be employed to receive one, more than one, or all the data streams carried by the composite stream. Likewise, a wireless terminal can transmit data to the base station or another wireless terminal. According to an example, a transmitter in a wireless communication system can utilize one or multiple sub-carriers for transmission. For a single transmitter with multiple sub-carriers, for instance, power can be efficiently allocated by evenly spreading power across the sub-carriers assuming that the channel is stationary (e.g., due to concavity of the Shannon capacity). However, when a second transmitter is introduced that transmits simultaneously as the first transmitter and therefore causes the transmitters to interfere with one another, the foregoing no longer holds true. For instance, when mobile devices are situated at the boundary of two cells, such devices can operate below 0 dB and thus experience significant diminution in quality of service. Moreover, when a single sub-carrier is employed by multiple interfering transmitters, similar inefficiencies and/or degraded service due to interference can commonly be experienced in connection with conventional power allocation techniques.
|
<SOH> SUMMARY <EOH>The following presents a simplified summary of one or more embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments, and is intended to neither identify key or critical elements of all embodiments nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later. In accordance with one or more embodiments and corresponding disclosure thereof, various aspects are described in connection with facilitating allocation of power levels in a wireless communication network. A metric based upon spectral efficiency can be employed in connection with optimizing power allocation. Further, power for transmitters to utilize can be assigned as a function of time. Moreover, a single sub-carrier network and/or a multiple sub-carrier networks can leverage one or more power allocation schemes. According to related aspects, a method that facilitates operating a communication network including a first wireless communication base station that includes a first sector is described herein. The method can include transmitting on a first channel at a first power level from the first sector during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth. Further, the method can comprise transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. Another aspect relates to a wireless communications apparatus. The wireless communications apparatus can include a memory that retains instructions related to transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern and transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. Moreover, the wireless communications apparatus can include a processor, coupled to the memory, configured to execute the instructions retained in the memory. Yet another aspect relates to a wireless communications apparatus that enables communicating with allocated power levels. The wireless communications apparatus can include means for transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth. Moreover, the wireless communications apparatus can comprise means for transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. Still another aspect relates to a machine-readable medium having stored thereon machine-executable instructions for transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth; and transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. In accordance with another aspect, an apparatus in a wireless communication system can include a processor, wherein the processor can be configured to transmit on a first channel at a first power level during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth. Further, the processor can be configured to transmit on the first channel at a second power level during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. To the accomplishment of the foregoing and related ends, the one or more embodiments comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more embodiments. These aspects are indicative, however, of but a few of the various ways in which the principles of various embodiments may be employed and the described embodiments are intended to include all such aspects and their equivalents.
|
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent application Ser. No. 60/844,817 entitled “POWER ALLOCATION IN A WIRELESS COMMUNICATION SYSTEM” which was filed Sep. 14, 2006 and U.S. Provisional Patent application Ser. No. 60/848,041 entitled “FRACTIONAL POWER REUSE IN A MULTICARRIER DOWNLINK” which was filed Sep. 26, 2006. The entireties of the aforementioned applications are herein incorporated by reference. BACKGROUND I. Field The following description relates generally to wireless communications, and more particularly to allocating power for transmitters in single-carrier or multi-carrier wireless communication systems. II. Background Wireless communication systems are widely deployed to provide various types of communication; for instance, voice and/or data can be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources. For instance, a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others. Common wireless communication systems employ one or more base stations that provide a coverage area. A typical base station can transmit multiple data streams for broadcast, multicast and/or unicast services, wherein a data stream can be a stream of data that can be of independent reception interest to a wireless terminal. A wireless terminal within the coverage area of such base station can be employed to receive one, more than one, or all the data streams carried by the composite stream. Likewise, a wireless terminal can transmit data to the base station or another wireless terminal. According to an example, a transmitter in a wireless communication system can utilize one or multiple sub-carriers for transmission. For a single transmitter with multiple sub-carriers, for instance, power can be efficiently allocated by evenly spreading power across the sub-carriers assuming that the channel is stationary (e.g., due to concavity of the Shannon capacity). However, when a second transmitter is introduced that transmits simultaneously as the first transmitter and therefore causes the transmitters to interfere with one another, the foregoing no longer holds true. For instance, when mobile devices are situated at the boundary of two cells, such devices can operate below 0 dB and thus experience significant diminution in quality of service. Moreover, when a single sub-carrier is employed by multiple interfering transmitters, similar inefficiencies and/or degraded service due to interference can commonly be experienced in connection with conventional power allocation techniques. SUMMARY The following presents a simplified summary of one or more embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments, and is intended to neither identify key or critical elements of all embodiments nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later. In accordance with one or more embodiments and corresponding disclosure thereof, various aspects are described in connection with facilitating allocation of power levels in a wireless communication network. A metric based upon spectral efficiency can be employed in connection with optimizing power allocation. Further, power for transmitters to utilize can be assigned as a function of time. Moreover, a single sub-carrier network and/or a multiple sub-carrier networks can leverage one or more power allocation schemes. According to related aspects, a method that facilitates operating a communication network including a first wireless communication base station that includes a first sector is described herein. The method can include transmitting on a first channel at a first power level from the first sector during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth. Further, the method can comprise transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. Another aspect relates to a wireless communications apparatus. The wireless communications apparatus can include a memory that retains instructions related to transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern and transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. Moreover, the wireless communications apparatus can include a processor, coupled to the memory, configured to execute the instructions retained in the memory. Yet another aspect relates to a wireless communications apparatus that enables communicating with allocated power levels. The wireless communications apparatus can include means for transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth. Moreover, the wireless communications apparatus can comprise means for transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. Still another aspect relates to a machine-readable medium having stored thereon machine-executable instructions for transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth; and transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. In accordance with another aspect, an apparatus in a wireless communication system can include a processor, wherein the processor can be configured to transmit on a first channel at a first power level during a first time period based on a first predetermined pattern, the first channel including a first frequency bandwidth. Further, the processor can be configured to transmit on the first channel at a second power level during a second time period based on the first predetermined pattern, the second power level is at least 0.5 dB different from the first power level. To the accomplishment of the foregoing and related ends, the one or more embodiments comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the one or more embodiments. These aspects are indicative, however, of but a few of the various ways in which the principles of various embodiments may be employed and the described embodiments are intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an illustration of a wireless communication system in accordance with various aspects set forth herein. FIG. 2 is an illustration of an example system that enables controlling power allocation for transmission within a cell or sector. FIG. 3 is an illustration of an example system that allocates power levels in a multiple sub-carrier network. FIG. 4 is an illustration of example even power level allocation scheme for a multiple sub-carrier system. FIG. 5 is an illustration of an example time varying power allocation scheme for a multiple sub-carrier system. FIG. 6 is an illustration of an example time varying power allocation scheme for a multiple sub-carrier environment. FIG. 7 is an illustration of an example time varying power allocation scheme for a single carrier system. FIG. 8 is an illustration of an example time varying power allocation scheme for a single carrier cellular data network. FIG. 9 is an illustration of an example sector-wise reuse multi-cell deployment in accordance with various aspects of the claimed subject matter. FIG. 10 is an illustration of an example cell-wise reuse deployment of multiple cells for a power allocation reuse scheme. FIG. 11 is an illustration of an example power allocation scheme for use with differing sectors according to various aspects of the claimed subject matter. FIG. 12 is an illustration of an example scheme that includes smooth power variation curves (e.g., power allocation curves, smooth power allocation pattern curves, . . . ) for disparate sectors (and/or cells). FIG. 13 is an illustration of another example power allocation scheme in accordance with various aspects of the claimed subject matter. FIG. 14 is an illustration of an example diagram of a capacity region for a two-user two-carrier single-cell system under a fixed power allocation. FIG. 15 is an illustration of an example graphical depiction of a proof in accordance with various aspects of the claimed subject matter. FIG. 16 is an illustration of an example diagram of a capacity region of (P1, P2) as compared to reuse-1. FIG. 17 is an illustration of an example diagram of capacity regions under reuse-1, general time/power sharing and superposition. FIG. 18 is an illustration of an example diagram of capacity regions for a two-user two-carrier two-cell system under reuse-1, reuse-2 and a (P1, P2) allocation. FIG. 19 is an illustration of an example diagram of various capacity regions. FIG. 20 is an illustration of an example diagram representing an achievable rate region under opportunistic power allocation. FIG. 21 is an illustration of an example diagram depicting channel conditions for two users within a cell under breathing cells where both channel gains can be normalized by the average channel gain of the good user. FIG. 22 is an illustration of an example diagram depicting a channel condition and normalized schedulable rate for different users in a breathing-cell scheme. FIG. 23 is an illustration of an example methodology that facilitates operating a communication network including a wireless communication base station that includes a first sector. FIG. 24 is an illustration of an example methodology that facilitates adaptively assigning power allocation patterns for allocating power levels. FIG. 25 is an illustration of an example methodology that facilitates operating a multiple carrier communication network including a first wireless communication base station that includes a first sector. FIG. 26 is an illustration of an example communication system implemented in accordance with various aspects including multiple cells. FIG. 27 is an illustration of an example base station in accordance with various aspects. FIG. 28 is an illustration of an example wireless terminal (e.g., mobile device, end node, . . . ) implemented in accordance with various aspects described herein. FIG. 29 is an illustration of an example system that enables communicating with allocated power levels. FIG. 30 is an illustration of an example system that enables communicating with allocated power levels in a multiple carrier wireless communication network. DETAILED DESCRIPTION Various embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that such embodiment(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments. As used in this application, the terms “component,” “module,” “system,” and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the Internet with other systems by way of the signal). Furthermore, various embodiments are described herein in connection with a wireless terminal. A wireless terminal can also be called a system, subscriber unit, subscriber station, mobile station, mobile, mobile device, remote station, remote terminal, access terminal, user terminal, terminal, wireless communication device, user agent, user device, or user equipment (UE). A wireless terminal may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having wireless connection capability, computing device, or other processing device connected to a wireless modem. Moreover, various embodiments are described herein in connection with a base station. A base station may be utilized for communicating with wireless terminal(s) and may also be referred to as an access point, Node B, or some other terminology. Moreover, various aspects or features described herein may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term “article of manufacture” as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer-readable media can include but are not limited to magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, etc.), optical disks (e.g., compact disk (CD), digital versatile disk (DVD), etc.), smart cards, and flash memory devices (e.g., EPROM, card, stick, key drive, etc.). Additionally, various storage media described herein can represent one or more devices and/or other machine-readable media for storing information. The term “machine-readable medium” can include, without being limited to, wireless channels and various other media capable of storing, containing, and/or carrying instruction(s) and/or data. Referring now to FIG. 1, a wireless communication system 100 is illustrated in accordance with various embodiments presented herein. System 100 can comprise one or more base stations 102 (e.g., access points) in one or more sectors that receive, transmit, repeat, etc., wireless communication signals to each other and/or to one or more mobile devices 104. Each base station 102 can comprise a transmitter chain and a receiver chain, each of which can in turn comprise a plurality of components associated with signal transmission and reception (e.g., processors, modulators, multiplexers, demodulators, demultiplexers, antennas, . . . ) as will be appreciated by one skilled in the art. Mobile devices 104 can be, for example, cellular phones, smart phones, laptops, handheld communication devices, handheld computing devices, satellite radios, global positioning systems, PDAs, and/or any other suitable device for communicating over wireless communication system 100. Base stations 102 can each communicate with one or more mobile devices 104. Base stations 102 can transmit information to mobile devices 104 over a forward link (downlink) and receive information from mobile devices 104 over a reverse link (uplink). Base stations 102 and mobile devices 104 can utilize one or multiple sub-carriers for communication there between. By way of illustration, a plurality of base stations 102 can each utilize a common sub-carrier or a common set of sub-carriers for downlink transmission. Additionally or alternatively, a common sub-carrier or set of sub-carriers can be utilized for uplink transmission (e.g., in one or multiple cells or sectors) by mobile devices 104 that can interfere with one another. System 100 can support differing types of users such as close-to-base station users and cell-boundary users. For close-to-base station users who may not be affected by inter-cell interference, even transmit power allocation across different carriers or frequency subbands can be more favorable since it offers more segments (or degrees of freedom). Meanwhile, cell-boundary users can benefit from schemes like simple frequency-reuse whereby some sub-carriers in each sector can be shut off since such a scheme can offer signal-to-noise (SNR) improvement that can compensate for the segment loss. When a mixture of users exists, the overall system throughput can be optimized (e.g., maximized) by assigning different powers to different carriers or frequency subbands. More particularly, system 100 can employ a time-varying power allocation scheme to leverage time flexibility to improve spectral efficiency, where the power allocation changes over time according to a pre-determined pattern. Various example power allocation schemes are provided below in accordance with various aspects of the claimed subject matter. Moreover, examples described herein relate to OFDM systems; however, it is to be appreciated that concepts provided herein can be applied to systems that leverage differing types of technologies (e.g., CMDA systems, GSM system, . . . ). With reference to FIG. 2, illustrated is an example system 200 that enables controlling power allocation for transmission within a cell or sector. System 200 includes a base station 202 that can communicate with one or more mobile devices 204-206 (e.g., mobile device 1 204, . . . , mobile device N 206, where N can be substantially any integer). Base station 202 can further include a power allocator 208 and a clock 210. Power allocator 208 can employ one or more of the example power allocation schemes described herein. Such schemes can enable optimizing performance (e.g., spectral efficiency) associated with a network. Moreover, power allocator 208 can utilize timing information obtained by clock 210 to schedule transmission (e.g., downlink transmission from base station 202 to one or more mobile devices 204-206, uplink transmission from mobile device 204-206 to base station 202, . . . ). For instance, timing information can be leveraged along with the power allocation scheme to select an identity of a transmitter and/or receiver as well as a power level to be utilized for transmission during a particular time slot. According to an example, system 200 can be a single carrier system; thus, a common carrier can be employed for communicating between base station 202 and mobile device(s) 204-206 (as well as for similar communication in disparate sector(s) and/or cell(s)). Base station 202 can be coordinated with disparate base stations (not shown) to implement a particular power allocation scheme; hence, power levels for transmission over the common carrier can be assigned by power allocator 208 as a function of time determined by clock 210. By way of illustration, power allocator 208 can assign a particular power level from a set of M discrete power levels, where M can be substantially any integer (e.g., employing the example schemes in FIGS. 7-8, 11). Base station 202 can utilize a set of discrete power levels that can be substantially similar to set(s) employed by disparate base stations in the network and/or the sets of discrete power levels can differ between base stations. According to an example, base station 202 can employ a set of discrete power levels that includes P1 and P2, while a neighboring base station (not shown) can utilize a set of discrete power levels that includes P3 and P4. For instance, P1 can be equal to P4 and P2 can be equal to P3; yet, it is contemplated that such power levels can differ from one another. Additionally or alternatively, P1 can be larger than P2 and P4 can be larger than P3; however, the claimed subject matter is not so limited. Power allocator 208 of base station 202 can assign a power level of P1 during a first time slot, P2 during a second time slot, etc. Moreover, a disparate power allocator of the neighboring base station can assign a power level of P3 during the first time slot, P4 during the second time slot, and so forth. The assigned power level for a particular time slot can be utilized by a transmitter (e.g., base station 202, one or more mobile device 204-206, . . . ) for communicating with a receiver (e.g., one or more mobile devices 204-206, base station 202, . . . ). Following this example, clock 210 can enable base station 202 to be synchronized with the neighboring base station (and/or any disparate base station(s)). Additionally, another example of a time-varying power allocation scheme is to enable both base station 202 and its neighboring base station choose a power allocation pattern with period 2 by repeating the two power levels chosen by each base station. Two signal-to-noise ratios (SNRs) can be measured by base station 202 for effectuating scheduling decisions. Such time division pattern reuse can be beneficial for delay sensitive users such as voice over IP (VOIP) users since the power levels can more rapidly change (as compared to use of smooth power allocation patterns) without providing a user with a bad SNR for a significant period of time. According to another illustration, power allocator 208 can use a smooth power allocation pattern for assigning power rather than a few discrete power levels (e.g., as described in FIGS. 12-13). The smooth power allocation pattern includes many more power levels into a set of possible power levels and enables assigning power levels with small differences to adjacent time intervals, which can enable smooth power variation over time and more importantly, easier tracking of the SNR. For instance, power allocator 208 can employ a power allocation pattern that can be close to a sinusoidal curve setting forth the power to be assigned as a function of time. The sinusoidal power allocation pattern can have a period of 100 time slots, for example; however, the claimed subject matter is not so limited as substantially any period or any curve is contemplated. Meanwhile, the power allocation pattern of a neighboring base station can be phase shifted (e.g., 180 degree shift if two power allocation patterns are utilized in a network, 120 degree shift if three power allocation patterns are utilized in the network, . . . ). Base stations within a network that utilize phase shifted power allocation patterns can be roughly synchronized (e.g., by respective clocks). According to another example, power allocation patterns utilized by differing base stations can be frequency shifted; thus, the sinusoidal curves of the power allocation patterns can have disparate frequencies. When differing frequencies are employed for the power allocation patterns, base stations need not be synchronized since over time differing channel conditions can be observed. It is to be appreciated that differing power allocation patterns can be employed by disparate sectors and/or different cells. For instance, with sector-wise reuse, each sector of a cell can utilize a differing power allocation pattern curve (e.g., respective phase shifted, frequency shifted, etc. patterns), while the cells in the network can repeat a similar reuse pattern (e.g., as shown in FIG. 9). Further, for cell-wise reuse, the sectors of a cell can each utilize a common power allocation pattern curve, and each cell can employ a differing power allocation pattern curve as compared to adjacent neighboring cells (e.g., as shown in FIG. 10). By way of further illustration, the power allocation pattern utilized by base station 202 can be predetermined and/or adaptively selected. According to an example, each sector and/or cell can be assigned a prefixed power allocation pattern. Pursuant to another illustration, the power allocation pattern for each sector and/or cell can be adaptive over time depending upon the load; thus, load information can be shared between sectors and/or cells to adjust mean, frequency, etc. associated with power allocation over time. Following this illustration where there are two cells, one cell can have 10 users and the other cell can have 100 users. The average power level for the cell with 10 users can be shifted down in comparison to the average power level for the cell with 100 users, for example; however, the claimed subject matter is not limited to the aforementioned example. Now turning to FIG. 3, illustrated is an example system 300 that allocates power levels in a multiple sub-carrier network. It is contemplated that any number of sub-carriers (e.g., carriers) can be supported by system 300. System 300 includes base station 202 and mobile devices 204-206 as described above. Base station 202 can further include power allocator 208 and clock 210. Moreover, base station 202 can include carrier selector 302 that can be utilized in conjunction with power allocator 208 to assign power levels to each of the carriers as a function of time (e.g., determined by clock 210). Thereafter, transmissions (e.g., users can be selected, . . . ) can be scheduled upon the carriers with the assigned power levels. According to an illustration, base station 202 can have a maximum power constraint. Moreover, carrier selector 302 and power allocator 208 can enable utilizing complementary patterns for power assignment for each of the carriers such that the sum of the power can remain constant for all of the carriers supported by base station 202. Carrier selector 302 and power allocator 208 can utilize discrete power levels and/or smooth power allocation pattern curves (e.g., sinusoidal curves for each sub-carrier that can be phase shifted and/or frequency shifted) in connection with assigning a power level to each of the carriers during each time slot. Moreover, the following provides example multiple sub-carrier schemes that can be utilized in connection with system 300. Turning to FIG. 4, illustrated is an example even power level allocation scheme 400 for a multiple sub-carrier system. According to this example, two transmitters can utilize two sub-carriers; however, it is to be appreciated that the claimed subject matter contemplates utilizing any number of transmitters and any number of sub-carriers. By way of illustration, each of the transmitters can be associated with a disparate sector and/or cell. The hatched bars 402 indicate power usage in sub-carrier 1 for transmitter 1, while the solid bars 404 indicate the power usage in sub-carrier 2 for transmitter 1. Also, the numbered blocks 406-408 represent the user scheduled at a time slot in each sub-carrier (e.g., number blocks 406 correspond to sub-carrier 1 and number blocks 408 correspond to sub-carrier 2 for transmitter 1). For instance, user 1 can be a cell-boundary user and user 2 can be a close-to-base station user. Additionally, hatched bars 410 represent power usage in sub-carrier 1 for transmitter 2 and solid bars 404 represent power usage in sub-carrier 2 for transmitter 2. Numbered blocks 414 indicate the user scheduled at each time upon sub-carrier 1 and numbered blocks 416 set forth the user scheduled during each time upon sub-carrier 2 for transmitter 2 (e.g., user 1′ can be a cell-boundary user and user 2′ can be a close-to-base station user). The power allocation for the two transmitters can be symmetric; thus, if (P1, P2) are assigned to the two sub-carriers (represented by f1 and f2, respectively) in transmitter 1, (P2, P1) will be assigned to sub-carriers in transmitter 2. Moreover, P1=P2=P/2, assuming P is a total available power at each transmitter. By utilizing the even power level allocation scheme 400, users at the boundary of two cells operate below 0 dB. Thus, scheme 400 can be favorable for close-to-base station users (e.g., user 2), while cell-boundary users can be associated with an SNR below 0 dB. On the other hand, if all power is assigned to one of the sub-carriers (not shown) (e.g., and the other sub-carrier is assigned zero power according to such scheme), the boundary user can have an SNR of hP/N0, where h is the path loss and N0 is noise power. Under an interference-limited scenario, the SNR can be larger than 0 dB, which can benefit cell-boundary users. However, by not utilizing one of the two sub-carriers, half of the degree of freedom is sacrificed (even though power gain can compensate for the loss to improve capacity for a boundary user), which can adversely impact close-to-base station users. Under the aforementioned schemes, neither the cell-boundary users nor the close-to-base station users may operate at their optimal operating power allocation point due to a tradeoff there between. With reference to FIG. 5, illustrated is an example time varying power allocation scheme 500 for a multiple sub-carrier system. Hatched bars 502 represent power allocated to sub-carrier 1 and solid bars 504 represent power allocated to sub-carrier 2 for transmitter 1. Moreover, blocks 506 identify a user scheduled in sub-carrier 1 at each time slot and blocks 508 identify a user scheduled in sub-carrier 2 at each time slot. Further, for transmitter 2, hatched bars 510 indicate power allocated to sub-carrier 1 and solid bars 512 indicate power allocated to sub-carrier 2, while blocks 514 relate to a user scheduled upon sub-carrier 1 and blocks 516 relate to a user scheduled upon sub-carrier 2. As depicted, power allotted for each of the sub-carriers can change as a function of time, and thus, the scheme 500 can improve overall spectral efficiency when leveraged by a variety of users (e.g., close-to-base station users (2, 2′) and cell-boundary users (1, 1′)). Rather than fixing the power allocation to be the same across time (as in scheme 400 of FIG. 4), the scheme 500 can change the power allocation to be either (P/2, P/2) or (P, 0) at differing times (e.g., for transmitter 1). Additionally, transmitter 2 can alternate the power allocation to be either (P/2, P/2) or (0, P) at differing times. For instance, during a first time slot shown, transmitter 1 can transmit on sub-carrier 1 to user 1 with a power of P, and during a second time slot can transmit to user 2 with a power level of P/2 on sub-carrier 1 and a power level of P/2 on sub-carrier 2, and so forth. Accordingly, during a subset of the time slots, sub-carrier 2 can be allocated zero power, and therefore, effectively be turned off. Meanwhile, transmitter 2 can transmit on sub-carrier 2 with a power of P to user 1′ during the first time slot and can transmit to user 2′ on both sub-carriers 1 and 2, each with a respective power of P/2, during the second time slot. As shown, the transmitters can be symmetric; however, it is contemplated that the claimed subject matter is not limited to utilizing symmetric power allocation patterns. For instance, it is to be appreciated that the transmitters can utilize substantially similar periodic power allocation patterns that have substantially similar periods, yet the patterns can be offset in phase from one another. Moreover, according to the illustrated example, user 1 and user 1′ can be cell-boundary users and user 2 and user 2′ can be close-to-base station users. More particularly, performance for the close-to-base station users can be substantially similar to a traditional even power allocation scheme (e.g., scheme 400 of FIG. 4). Further, the cell-boundary users can experience an improved data rate although fewer segments are assigned to such users; the improvement in the interference-limited scenario can be due to increased SNR. Referring to FIG. 6, illustrated is another example time varying power allocation scheme 600 for a multiple sub-carrier environment. Hatched bars 602 represent power usage in sub-carrier 1 and solid bars 604 represent power usage in sub-carrier 2 for transmitter 1. Further, blocks 606 indicate an identity of a user scheduled at each time slot for sub-carrier 1 and blocks 608 indicate an identity of a user scheduled at each time slot for sub-carrier 2 (e.g., where user 1 can be a cell-boundary user and user 2 can be a close-to-base station user). Additionally, hatched bars 610 indicate power usage in sub-carrier 1 and solid bars 612 indicate power usage in sub-carrier 2 for transmitter 2, with blocks 614-616 providing the corresponding user identities scheduled upon the respective sub-carrier (e.g., user 1′ being a cell-boundary user and user 2′ being a close-to-base station user). To improve spectral efficiency, the scheme 600 can improve the data rate of close-to-base station users (e.g., in comparison to the scheme 500 of FIG. 5). The scheme 600 can improve performance of close-to-base station users while maintaining enhanced performance for cell-boundary users in comparison to an even power allocation scheme (e.g., the scheme 400 of FIG. 4). In particular, the scheme 600 does not shut off one of the sub-carriers (e.g., sub-carrier 2 for transmitter 1, sub-carrier 1 for transmitter 2, . . . ) during a subset of time slots. Rather, a low power level is allotted during such time slots to maintain the SNR improvement for boundary users that can be significant enough to compensate for the segment loss (e.g., since the cell-boundary users can be scheduled upon half of the segments as compared to scheduling in an even power allocation scheme). Moreover, close-to-base station users (e.g., user 2, user 2′) can be scheduled to the low power level segments. Now referring to FIG. 7, illustrated is an example time varying power allocation scheme 700 for a single carrier system. Accordingly, power levels for the single carrier can be coordinated at different sectors (and/or different cells) during each time slot. Bars 702 represent power levels in a first sector during each time slot and bars 704 represent power levels in a second sector during each of the time slots. Moreover, blocks 706 identify a user assigned to each time slot upon the carrier in the first sector and blocks 708 identify a user assigned to each time slot upon the carrier in the second sector. For example, user 1 and user 1′ can be cell-boundary users and user 2 and user 2′ can be close-to-base station users. Further, the transmitters associated with each of the sectors can interfere with each other. The scheme 700 can yield a spectral efficiency improvement similar to that demonstrated in scheme 500 of FIG. 5. In particular, at a first time slot, a cell-boundary user can be assigned a power P in a first sector, while no assignment can be provided to a user in the second sector. Next, at a second time slot, a close-to-base station user can be assigned a power P/2 in the first sector and a disparate close-to-base station user can be assigned a power P/2 in the second sector. Further, at third time slot, a cell-boundary user can be assigned a power P in the second sector and an assignment can be lacking for the first sector. Moreover, during a fourth time slot, the close-to-base station users can again be scheduled, and so forth. Turning to FIG. 8, illustrated is another example time varying power allocation scheme 800 for a single carrier cellular data network. The scheme 800 includes bars 802 related to power levels during each time slot for a first sector and bars 804 related to power levels during each time slot for a second sector. Moreover, blocks 806 identify a user assigned to each time slot for the first sector and blocks 808 identify a user assigned to each time slot for the second sector (e.g., user 1 and user 1′ can be cell-boundary users, user 2 and user 2′ can be close-to-base station users, . . . ). The scheme 800 provides additional segments for close-to-base station users (e.g., user 2, user 2′, . . . ) to be scheduled upon. In particular, rather than allotting a power level of zero to a first sector and P to a second sector during a time slot, the first sector can be assigned a low power level that is greater than zero (e.g., while the second sector can be allocated a high power level less than P). Accordingly, a close-to-base station user can utilize the low power level associated with the first sector and a cell-boundary user can be assigned to the high power level corresponding to the second sector during this particular time slot. Additionally, during a next time slot, the power levels for each of the sectors can be substantially similar (e.g., middle power level) and close-to-base station users can be assigned to utilize the sub-carrier in each of these sectors. Referring to FIG. 9, illustrated is an example sector-wise reuse multi-cell deployment 900 in accordance with various aspects of the claimed subject matter. As depicted, the multi-cell deployment 900 can comprise multiple cells 902 dispersed over a geographic area to form a communication network. Each of the cells 902 can include three sectors as shown; however, it is contemplated that one or more of the cells 902 can include fewer than and/or greater than three sectors. Further, it is to be appreciated that the multi-cell deployment 900 can support multiple carriers and/or a single carrier. The sectorized cells 902 can be located in a regular hexagon grid and can extend beyond the grid depicted (e.g., any number of cells 902 can be included in the grid, . . . ). For each of the sectors of the cells 902, a power variation curve (e.g., P1, P2, P3, . . . ) can be chosen; further, the curves can be reused across all of the sectors. According to the illustrated example, three distinct power variation curves (e.g., power allocation curves, smooth power allocation pattern curves, . . . ) can respectively be allocated to each of the three sectors of each of the cells 902; thus, sector 1 can be allocated power variation curve 1 (P1), sector 2 can be allocated power variation curve 2 (P2), and sector 3 can be allocated power variation curve 3 (P3). Moreover, the same pattern can be reused across all of the cells 902. FIG. 10 illustrates an example cell-wise reuse deployment 1000 of multiple cells for a power allocation reuse scheme. A plurality of cells 1002, 1004, 1006 are included within the grid associated with the deployment 1000. As shown, the cells 1002-1006 include three sectors; however, the claimed subject matter is not limited to utilization of cells with three sectors. The deployment 1000 can be employed when leakages from intra-cell sectors are significant. In particular, the deployment 1000 can use substantially similar power variation curves for sectors inside the same cell and different power variation curves across different cells. Thus, according to the depicted example, cells 1002 can include three sectors that utilize power variation curve 1 (P1), cells 1004 can include three sectors that employ power variation curve 2 (P2), and cells 1006 can include three sectors that use power variation curve 3 (P3). Further, each cell 1002 can be adjacent to cell(s) 1004 and/or cell(s) 1006 (and cells 1004 and cells 1006 can similarly be adjacent to differing types of cells), and therefore, adjacent cells can utilize differing power variation curves (e.g., a cell 1002 is not directly adjacent to another cell 1002). It is contemplated, however, that any number of differing power variation curves can be employed by different cells, and thus, the claimed subject matter is not limited to the illustrated example. Now turning to FIG. 11, illustrated is an example power allocation scheme 1100 for use with differing sectors according to various aspects of the claimed subject matter. The scheme 1100 includes three power variation curves 1102, 1104, and 1106 that can be allocated to differing sectors. The power variation curves 1102-1106 can utilize a common carrier (e.g., for use in a single carrier system). By way of example, a cell (e.g., the cell 902 from FIG. 9) can include three sectors, and each one of the sectors can be assigned a respective one of the power variation curves 1102-1106. Moreover, a similar pattern (e.g., assigning power variation curves 1102-1106 to sectors) can be repeated throughout a set of cells. According to another illustration, each sector of a cell can utilize one of the power variation curves (e.g., the power variation curve 1102), and disparate power variation curves (e.g., the power variation curves 1104, 1106) can be employed by directly adjacent cells (e.g., in accordance with the deployment 1000 of FIG. 10). The scheme 1100 varies the power allocation in a slot-by-slot basis. Thus, sectors in a network can employ at least some synchronization to coordinate power of each sector during each time slot. For example, a time division duplexing (TDD) system can support the scheme 1100; however, the claimed subject matter is not so limited. Moreover, the power variation curve 1102-1106 employed by a particular sector can provide three states as a function of the power level; hence, a base station can track variation of the SNRs under each state to make scheduling decisions. Now referring to FIG. 12, illustrated is an example scheme 1200 that includes smooth power variation curves for disparate sectors (and/or cells). The illustrated example includes three power variation curves 1202, 1204, 1206; however, it is contemplated that a system can employ less than or greater than three power variation curves. As shown, each of the three power variation curves 1202-1206 can be offset by 120 degrees in phase from one another (e.g., if two curves are utilized in a disparate system, the curves can be offset by 180 degrees, if four curves are employed then the offset can be 90 degrees, . . . ). According to an example, the power variation curve 1202 can be assigned to all sectors in a cell, and directly neighboring cells can utilize the power variation curve 1204 and/or the power variation curve 1206. Pursuant to another illustration, a cell can include three sectors, each of which can employ a corresponding one of the power variation curves 1202-1206 (e.g., such a pattern can be repeated across a plurality of cells). The scheme 1200 can be employed when a coarser synchronization is available over sectors (as compared to the slot-by-slot synchronization used with the scheme 1100 of FIG. 11). Thus, slot-by-slot synchronization need not be utilized with the scheme 1200. Moreover, the relative power level can be defined in a linear scale and/or can be offset. Further, the maximum relative power offset can be scaled by a constant instead of being fixed to 1. FIG. 13 illustrates another example power allocation scheme 1300 in accordance with various aspects of the claimed subject matter. The scheme 1300 includes three power variation curves 1302, 1304, 1306, each with a disparate frequency. By employing the different frequencies for power variation curves 1302-1306 utilized by disparate sectors, a system need not be synchronized. It is contemplated that any frequencies can be utilized for power variation curves 1302-1306. Moreover, it is to be appreciated that fewer than and/or more than three power variation curves can be utilized in a system. The following set forth in connection with FIGS. 14-22 provides additional discussion with regards to various aspects, features, techniques, etc. associated with the claimed subject matter. With the advent of wideband cellular communications, more and more attention has been drawn to the problem of how to efficiently communicate in a multiple-carrier system. A possible solution to address this problem is to look at the frequency-reuse schemes, which is fairly well studied in narrow-band systems, for example, GSM networks. Specifically, in narrow-band networks, operators typically choose to allocate only part of the total bandwidth to each cell such that the inter-cell interference can be controlled to be negligible. A scheme which allocates 1/N of the total bandwidth to each cell is referred to as a reuse-N scheme. In narrow-band networks, reuse-N (e.g., where N can be dependent on the geometry of the deployment) can be utilized in a multi-cell deployment since the dynamic range of the inter-cell interference from neighboring cells due to different locations of mobiles can make reliable communications difficult. With CDMA and OFDM technologies, reuse-1 systems can be employed due to the salient feature of inter-cell interference averaging. Specifically, the inter-cell interference in CDMA and OFDM technologies are averaged over the total bandwidth within a carrier due to the presence of pseudo-noise signature sequence in CDMA systems and independent tone-hopping in OFDM systems. However, in a reuse-1 deployment, the cell boundary users still suffer from an average SNR below 0 dB. In a typical hexagon deployment, 30 percent of the users can have an average SNR below 0 dB, for example. To satisfy certain fairness constraints between cell boundary users and other users, the system has to spend a lot of resource on the cell boundary users, which restricts overall system performance. It thus can be desirable to reduce the number of cell boundary users or completely remove the cell boundary, if possible. Towards this end, the reuse-N schemes can be attractive for wideband systems. For example, for the regular hexagon deployment, a reuse-3 scheme can prevent inter-cell interference from direct neighboring cells and thus reduce the number of cell boundary users. Of course, for a reuse-3 deployment, the system now uses 3 carriers and occupies three times the bandwidth as compared to a single-carrier system. Thus, a fair comparison to make here is to compare between systems with the same bandwidth usage. Under certain performance metric, reuse-3 can outperform reuse-1. However, if networks with mainly elastic traffic sources are considered, for example, delay-insensitive data users, reuse-3 may not be the best choice due to its conservativeness in bandwidth reuse. Each cell only uses ⅓ of the total bandwidth to achieve a power gain for the cell boundary users and a tradeoff from bandwidth to power is usually not beneficial. Towards this end, a more flexible “frequency-reuse” scheme, which is referred to as a Flex-Band scheme, can be utilized. In the Flex-Band proposal, all carriers can be used in all cells. Thus, from frequency-reuse point of view, it is a reuse-1 approach. However, each carrier is allowed to choose a different power level in the same cell. Different cells use a different power-reuse scheme within the cell. Apparently, the Flex-Band proposal is essentially a fractional power reuse scheme and both the simple frequency reuse-1 scheme and reuse-3 scheme are special cases of it. For brevity of notation, the frequency reuse-1 scheme can be referred to as the reuse-1 scheme and the frequency reuse-N scheme can be referred to as reuse-N scheme. In cellular networks, the spectral efficiency can be defined as the data capacity normalized by bandwidth. Moreover, the spectral efficiency can be an important system performance metric to compare between different technologies. Specifically, the spectral efficiency is the cell overall throughput normalized by bandwidth when certain number of data users are dropped uniformly in cells. Further, the cell throughput is measured when a certain fairness criterion is enforced among different users in the system (e.g., the system can not maximize its throughput by putting all its resource to close-to-base station users). The following analyzes whether it is beneficial to adopt a fractional power reuse scheme in a multi-carrier downlink, from a spectral efficiency point of view. Specifically, the capacity region of the system under a fractional power reuse scheme can be studied and compared to the capacity region under the even-power-allocation scheme. For instance, the following can be determined: (1) In a single-cell TDMA scheme where a user is scheduled in each time slot with a fixed power constraint, a fractional power reuse scheme can yield a better capacity region as compared to the reuse-1 scheme. However, the improvement can be slim and if more than one user that can be scheduled is used in each carrier, the same improvement can be achieved even with the reuse-1 scheme. (2) In a multi-cell system, the capacity region can be improved by fractional power reuse. This improvement can not be achieved by relaxing the one-user-per-slot policy and this shows that fractional power reuse can enable achieving the capacity region in a multi-cell multi-user system. (3) The capacity region of a multi-cell system can be further improved by introducing time variation in the fractional power reuse scheme, which is an opportunistic power reuse scheme and is also referred to the breathing-cell scheme. In this scheme, each cell can vary its transmit power with a different frequency and/or phase, or equivalently saying, with a different power allocation pattern. The total number of power allocation patterns can be limited and can be reused over the entire network. Each cell can schedule cell boundary users when the channel condition (e.g., depending on its current transmit power and inter-cell interference) is good and can schedule close-to-base station users when the channel is bad. A wideband cellular downlink can be considered with a given number of carriers. Communications scheduled in different carriers do not interfere with each other while simultaneous communications in same carriers in different cells create inter-cell interference. This is also referred to as the co-channel interference. Theoretically, if we assume perfect backhaul between the base stations, one can apply Costa Pre-coding at each base station to remove the co-channel interference, if the concurrent communications in neighboring cells can be known in a non-causal way. However, such a scheme may not be practical in reality due to the following two difficulties: (i) Costa pre-coding uses perfect knowledge of the channel side information at the base station; (ii) this scheme leverages symbol-level global system synchronization. Additionally, the complexity of such a scheme is very high. Thus, it is not assumed that such schemes are to be used at the base stations. Each base station can treat the inter-cell interference as a pure additive to the noise which can not be taken advantage of. For simplicity, time can be assumed to be slotted. In each time slot, one user per carrier per cell can be allowed to transmit (e.g., a TDMA scheme). TDMA downlink has been adopted into many systems including IS-856 (EV-DO) systems, for example. With this assumption, intra-cell interference can be mitigated and thus the effect of power reuse schemes on the inter-cell interference can be reviewed. It is to be appreciated that although a TDMA approach is described herein, more than one user can be allowed to be scheduled within the same slot using an orthogonal system resource, which is possible in an OFDM-based network. Users can be considered to be stationary (e.g., the channel is AWGN between the user and the base station or the channel varies in a slower time scale as compared to the communication time scale). When a user i is assigned the slot t, it can transmit at a rate of C i ( t ) = log 2 ( 1 + h i P i ( t ) N 0 ) bits per second, where hi is the channel gain between user i and its serving base station and Pi(t) is its transmit power at time t. No is the noise power density (e.g., the following assigned No=1). Further, a power budget at the base station (e.g., the average power used per carrier) can be bounded by Pm. A determination can be made as to how to allocate power levels to different carriers in different cells to maximize the system capacity. In a data network, the spectral efficiency (bits per second per Hertz) can be a useful capacity metric to compare different networks, where all users are assumed to be infinite-backlogged. However, spectral efficiency is usually defined associated with a given fairness criterion between users within the network and is thus hard to characterize in closed-form expressions. Thus, the following considers the capacity region instead of the spectral efficiency. The spectral efficiency under a fairness constraint can be viewed as an operating point within the capacity region. By considering the capacity region, the impact of different schemes under different fairness constraints can be evaluated. According to an example, the capacity region for a two-user system can be considered, where one user is chosen to be a cell-boundary user while the other one is close to the base station. This model can be a good simplification of a loaded system where multiple users are dropped uniformly in each cell. Each mobile can be a wideband mobile (e.g., it can be scheduled in part of or all the carriers). The system scheduler can choose which users to transmit on each carrier without worrying about whether or not a mobile can transmit/receive on a particular carrier. Single cell scenario: When only a single cell and a single user are considered, the problem considered degrades to a point-to-point communication problem over parallel channels. In such a scenario, due to the concavity of the Shannon capacity formula, it is optimal to allocate your power evenly across the parallel channels and make full use of the available degrees of freedom (e.g., there is no benefit to vary the power allocation across carriers or time). However, in a multi-user scenario, such observation is not true anymore. In other words, benefit can be obtained from varying power across carrier or time to do better than the even-power-allocation scheme. For convenience, in the following, the even-power-allocation scheme is referred to as a simple Reuse-1 scheme. Next, the capacity region for two users under a two carrier system with a fixed power allocation scheme can be evaluated, where each carrier chooses a time-invariant power level. Capacity region under fixed power allocation scheme: In this section, a two-user single-cell system with two carriers is evaluated. The power vector allocated to the two carriers is (P1, P2). The main result of this section is summarized in the following theorem. Theorem 1: Assume the path-loss gains for the two users in the system are h1, h2 and satisfy h2≧h1. The capacity region under a fixed power allocation scheme (P1, P2) (P2≧P1) is the convex hull of four capacity vectors (0, 0), (R1, 0), (0, R2), and (R′1, R′2), where R1, R2, R′1, R′2 are defined below. R1=log2(1+h1P1)+log2(1+h1P2); (1) R2=log2(1+h2P1)+log2(1+h2P2); (2) R′1=log2(1+h1P2); (3) R′2=log2(1+h2P1). (4) Remark: The capacity region illustrated in FIG. 14 is a polygon with vertexes given by (0, 0), (R1, 0), (0, R2), and (R′1, R′2). Ri (i=1, 2) is the capacity of user i when both carriers schedule user i only all the time. Since h2>h1, user 1 can be referred to as the bad user and user 2 as the good user. Similarly, carrier 1 can be referred to as the good carrier and carrier 2 as the bad carrier. (R′1, R′2) is the capacity tuple when the good user is scheduled on a bad carrier only and the bad user is scheduled on the good carrier only. FIG. 14 shows an example of such a region. This region is essentially a convolution of the capacity regions for the two carriers. Specifically, the region consists of all rate tuples which can be expressed in the form of the summations of two rate tuples, each belonging to the capacity region of a carrier. Such sum is also referred to as the Minkawski sum of two convex regions. Proof: The achievability can be simple. By scheduling only user 1 to carrier 2 (e.g., the bad user uses all the resource of the good carrier), and by varying the fraction of time that user 1 is scheduled in carrier 2, points on the straight line with end points (R1, 0) and (R′1, R′2) can be achieved. On the other hand, by scheduling only user 2 to carrier 1 and varying the fraction of time that user 2 is scheduled within carrier 2, the straight line between (0, R2) and (R′1, R′2) can be achieved. FIG. 15 illustrates the converse via a graphical approach. In FIG. 15, straight line I denotes the boundary of the capacity region for carrier 1, II denotes the boundary of the capacity region for carrier 2. An observation that can be made here is if the two capacity regions for the two carriers are compared, such that the bad user can be improved by a larger factor by scheduling it on the good carrier. This is again due to the concavity of the capacity. Thus, line I is steeper as compared to line II. The capacity region of the two-carrier system is then the set of rate tuples which can be written as the summation of a rate tuple within the capacity region of carrier 1 and a rate tuple within the capacity region of carrier 2. For simplicity, the capacity region can be equal to I+II. Apparently, the capacity region has to be bounded by both I+II′ and I′+II, where I′ and II′ are also shown in FIG. 15. Specifically, line I′ is parallel to II and intersects the R2 axis at the same end point as I. II′ is parallel to I and intersects the R1 axis at the same end point as II. Similarly, straight line III is parallel to straight lines I′ and II and intersects the R2 axis at (0, R2) while straight line IV is parallel to straight lines I and II′ and intersects the R1 axis at (R1, 0). Further, it can be shown that III=I′+II and IV=I+II′. To see that III=I′+II (the other proof can be similar), it suffices to see that the summation of any point (x1, y1) on I′ and any point (x2, y2) on II has to reside on III. This is true since I′ and II have the same slope and thus the two points can be represented by the following: y1=−sx1+c1; y2=−sx2+c2, where s is the common slope and c1, c2 are two constants. It can be seen that y1+y2=−s(x1+x2)+c1+c2, for any choice of (x1, y1)εI′ and (x2, y2)εII. Next, the straight line y=−sx+c1+c2, (5) can be shown to coincide with III. It suffices to show that (0, R2) satisfy (5), e.g., R2=c1+c2. This is trivial since c1 and c2 are the rate that user 2 can achieve within carrier 1 and 2 when all resources are allocated to it while R2 is maximum rate user 2 can get in both carriers. The theorem follows. A by-product of the proof above is that the optimal scheduling policy of a multi-carrier system, from a capacity point of view, can be determined. Corollary 1: To achieve any point on boundary of the capacity region of a fixed power-allocation two-carrier system, at least one of the followings must be true (1) the good user is only scheduled in the bad carrier; or (2) the bad user is only scheduled in the good carrier. Proof: Assume that there is a point on the boundary of the capacity region shown above which can be achieved by a scheme without satisfying condition (1) or (2). Equivalently saying, a scheme where both users are scheduled to both carriers which actually achieves a rate tuple on the capacity boundary can be utilized. Assuming αij=(i,j=1, 2) to be the time fraction that user i is scheduled on carrier j. Thus, α11+α21=α12+α22=1. The rate tuple achieved by this scheme is thus (α11C11+α12C12,α21C21+α22C22), where Cij is a capacity of user i when scheduled in carrier j, e.g., Cij=log2(1+hiPj). Thus, an observation that can be made is that: C 12 C 11 > C 22 C 21 , ( 6 ) e.g., the benefit of scheduling the bad user in the good carrier is dominating the benefit of scheduling the good user there. It can be shown that this rate tuple cannot be on the boundary if both α11 and α22 are non-zero, e.g., there exists an achievable rate tuple which is strictly larger than this one component wisely. To see this, the rate tuple achieved under time fraction βij can be considered, where βij is again the time fraction that user i is scheduled on carrier j. Moreover, βij can be chosen as follows: β11=α11−η; β12=α12+ε; β21=α21+η; β22=α22−ε, where η and ε are small positive numbers which satisfy C 22 C 21 < η ɛ < C 12 C 11 . Since α's are positive, small enough η and ε can be identified such that the β's are positive as well. The rate tuple achieved by this scheme can be seen to be (α11C11+α12C12−ηC11+εC12,α21C21+α22C22+ηC21−εC22) which is larger than the rate tuple under αij component wisely. Thus, there exists a contradiction. Remarks: This corollary gives a general guideline for scheduling policies in a multi-carrier system. As shown below, the same rule is also true in a multi-cell system where inter-cell interference exists. Comparison to the reuse-1 scheme: The capacity region under a fixed power allocation scheme was evaluated above. Now, it can be determined whether or not it is optimal to allocate power evenly across the carriers, by comparing the capacity region under a general (P1, P2) allocation to the one under reuse-1 scheme. Apparently, for the two extreme points (R1, 0) and (0, R2), to deviate from the simple reuse-1 scheme is suboptimal as seen in the single user case. But it is not yet proved if the capacity region under a general (P1, P2) scheme is a subset of the capacity region under the even-power-allocation scheme. By choosing (P1, P2) carefully, beneficial results can be obtained in comparison to the even-power-allocation scheme in some part of the capacity region. Lemma 1: Consider a two-user two-carrier single-cell system with h1<h2. There exist a power allocation scheme (P1, P2) such that the capacity region under (P1, P2) is not a subset of the capacity region under Reuse-1 scheme. Proof: To see this, the point (R′1, R′2) as defined in (3) and (4) is considered. Since the capacity region under Reuse-1 is a linear region under the system assumption, (R′1, R′2) is a candidate to consider here because it is the vertex of the polygon which may not be included in the Reuse-1 capacity region. The capacity region can be written as { ( R 1 , R 2 ) : R 1 2 log 2 ( 1 + h 1 P m ) + R 2 2 log 2 ( 1 + h 2 P m ) ≤ 1 } . Thus, it suffices to show that there exists an αε(0, 1] such that (P1, P2)=((1−α)Pm, (1+α)Pm) and log 2 ( 1 + h 1 P 2 ) 2 log 2 ( 1 + h 1 P m ) + log 2 ( 1 + h 2 P 1 ) 2 log 2 ( 1 + h 2 P m ) > 1. The left-hand-side of the inequality above can be defined as g(α). Thus, g(0)=1. (7) Further, the first-order derivative of g(α) is g ′ ( a ) = 1 log 2 ( 1 + h 1 P m ) 1 1 + α h 1 P m 1 + h 1 P m h 1 P m 1 + h 1 P m - 1 log 2 ( 1 + h 2 P m ) 1 1 - α h 2 P m 1 + h 2 P m h 2 P m 1 + h 2 P m . Further, g′(0)>0, (8) if h1<h2. This can be true because g ′ ( 0 ) = 1 log 2 ( 1 + h 1 P m ) h 1 P m 1 + h 1 P m - 1 log 2 ( 1 + h 2 P m ) h 2 P m 1 + h 2 P m g ′ ( 0 ) = f ( h 1 P m ) - f ( h 2 P m ) where f(.) can be defined as f ( x ) = 1 log 2 ( 1 + x ) x 1 + x and can be shown to be a monotone decrease function for x>0. The lemma follows from (7) and (8). From here, if (P1, P2) is chosen appropriately, better results can be obtained than the reuse-1 scheme for certain choice of utility function, or equivalently, fairness criterion. On the other hand, an uneven power allocation leads to a sub-optimal performance when the operating point shifts to the end points where most system resource is allocated to one of the users. Such properties are depicted in FIG. 16. Capacity region under opportunistic power allocation: The capacity region for a single-cell two-carrier system can be considered, by introducing time-varying power allocation across time. Specifically, in each time slot, the scheduler of the system can determine both (1) which user to transmit on each carrier, and (2) which power level to use on each carrier under the average power constraint. The benefit of allowing time-varying power allocation is apparent from FIG. 16. As illustrated, curve 1602 is a capacity region under reuse-1, curve 1604 is a capacity region under (P1, P2), and curve 1606 is a capacity region under time-sharing. As shown in FIG. 16, a naive lower bound to the true capacity region can be obtained by performing time-sharing between the two end-points of the reuse-1 scheme and the better-performance point (R′1, R′2) under any power allocation scheme. This yields a capacity-region curve consist of two straight lines which can outperform reuse-1 at all points. The capacity region can further be optimized by looking at all possible (P1, P2) allocations. However, this scheme is not necessarily optimal. Next, it can be determined whether further optimization can be obtained and/or what is the optimal user and power scheduling policy as shown in the next theorem. Theorem 2: Assume the path-loss gains for the two users in the system are h1, h2. The capacity region of the single-cell two-carrier system is the convex hull of following rate tuples {(2α log2(1+h1P1),2(1−α)log2(1+h2P2)):0≦α≦1,αP1+(1−α)P2=Pm}. Remarks: In the expression above, α is the usual time-sharing parameter, which represents the time fraction that the system is scheduling one of the users. P1 and P2 can be viewed as the power-sharing parameters. This theorem yield that to achieve any point on the boundary of the capacity region under the one-user-per-slot-per-carrier constraint, the optimal strategy utilizes a time/power sharing strategy instead of the simple time-sharing strategy, which yields the straight-line region under reuse-1. In this strategy, the system picks different power levels accordingly when it schedules different users. After a power level is picked, the system sticks to it when the same user is scheduled. Proof: Achievability is trivial. User 1 can be scheduled in α of the total segments over both carriers and use power P1 to transmit. User 2 is scheduled 1−α of the total segments using P2. For the converse, it can be argued that any rate tuple which is out of capacity region defined above may not be achieved. For any scheduling policy, it can be assumed that user 1 gets a fraction of the total segments with average power P1 and user 2 gets the rest of the segments with average transmit power P2. Due to the concavity of the capacity, the rate that user 1 obtained under this scheduling policy is upper bounded by 2α log2(1+h1P1) which is achieved by spreading the power evenly across the segments (or degrees of freedom) assigned to that user. A similar argument can be made with regarding to user 2. Another observation that can be made is that in the proof of Theorem 2, the fact that there are two carriers can be irrelevant. Such a scheme can be easily extend to the single-carrier system, where flexible time/power sharing can be applied to achieve a better capacity region as compared to the simple reuse-1 scheme. A comparison between the capacity region under this scheme and the reuse-1 scheme is shown in FIG. 17. FIG. 17 illustrates an example comparison of capacity regions under simple reuse-1, general time/power sharing and superposition. As depicted, 1702 represents a capacity region under reuse-1, 1704 depicts a capacity region under opportunistic power allocation, and 1706 represents a capacity region under super-position. The benefit of flexible time/power sharing against the simple reuse-1 scheme can decrease as the difference between two users gets smaller. Further, if the one-user-per-slot constraint is removed to allow scheduling multiple users, then the information-theoretic capacity region is achieved by super-position coding and decoding, which can be better than the capacity region under time/power sharing. To allow power to vary over time arbitrarily may not be desirable in cellular networks since it will cause fluctuation in inter-cell interference and thus make channel quality tracking difficult. On the other hand, superposition coding also adds complexity to the system. Accordingly, alternative ways to achieve the capacity region beyond the linear Reuse-1 region without applying either time/power sharing or superposition coding can be leveraged. A possibility to improve the spectral efficiency is to introduce the multi-carrier system. To have a two-carrier system can achieve some rate tuples outside the linear region, by choosing power levels and scheduling policies carefully. Now consider a system with infinite number of carriers. In this case, the capacity region (normalized by the number of carriers) can be the same as the single-carrier capacity region under flexible time/power sharing, since power can be assigned to carriers in a similar way to that proposed in the time/power sharing scheme in the time domain. When considering a finite number of carriers, a quantization error can result if time-varying power allocation is not allowed. Specifically, the percentage of degrees of freedom using a specific power level is not of infinite precision any more. Thus, the capacity region achievable with a finite number of carriers will be a subset of the single-carrier capacity region under time/power sharing. In an orthogonal system, for example, an OFDM system, the super linear capacity region can be achieved even with a single carrier since multiple sub-carrier tones can be included within a carrier. If more than one user is allowed to schedule in the same time slot within the same carrier, then more energy can be used on some of the tones where the bad user can be scheduled while the good user can be scheduled at the rest of the tones. Additionally, a single cell scenario can be similar to a multi-carrier system under the one user per carrier per slot constraint. Two-cell Scenario: A two-cell scenario can be evaluated. Similar to the single-cell scenario, the capacity region for a multi-carrier system can be reviewed and then the capacity region under an opportunistic power allocation scheme can be analyzed, which can be applied to single carrier systems. For a two-cell case, the definition of capacity region can be slightly different from the capacity region described above. For instance, the following provides assumptions and defines capacity region in connection with the two-cell scenario. Definitions and assumptions: The capacity region described for the two-cell scenario can be the capacity region for users in one of the cells. The cell of interest can be referred to as the primary cell and the other cell can be referred to as the interfering cell or simply the interferer. Clearly, the capacity region of the primary cell depends on the transmitting power in the interferer cell. The interferer can be assumed to be blasting at the maximum allowed power in its carriers. This assumption is valid in a loaded system where the spectral efficiency is calculated. Another factor which will affect the capacity region is the power allocation in the carriers of the interferer cell. Towards this end, another assumption can relate to the symmetry between these two cells. Specifically, assume L carriers in each cell and assume that the primary call assign power vector P=(P1, P2, . . . , PL) to the L carriers. By the symmetry assumption, the power allocation can be constrained in the interferer cell to be a permutation of P. Further, assuming πij to be the fraction of carriers where the primary cell assigns power level Pi and the interferer assigns Pj, then πij=πji. As an example, consider the case where two carriers exist in each cell. If (P1, P2) is used in the primary, then the symmetry assumption constrains the power allocation to the two carriers in the interferer to be either (P1, P2) or (P2, P1). Any other power allocations (e.g., power allocations using any other power levels) in the interferer can be excluded. Due the presence of the interferer, the channel quality from a mobile to both cells can affect the performance for a user. For notational convenience, ηi to be the path loss ratio of user i, e.g., η i = h i ( 2 ) h i ( 1 ) , where hi(k) represents the path loss gain between user i and cell k. After introducing ηi, the super index for the h's and a user's channel need not be used and can be represented by the channel gain hi and the path loss ratio ηi. In general, hi and ηi are not necessarily fully correlated. If there are two mobiles, for example, the one with better hi can have a larger path loss ratio. To reduce the complexity of the problem, it can be assumed that ηi and hi are fully correlated when multiple users are considered, e.g., if h2≧h1, then η2≦η1. With this assumption, for users with better channel quality, they see less interference from the interferer too and thus the path loss hi can distinguish between a “good” user and a “bad” user. System capacity with two carriers under fixed power allocation: First, two carriers in each cell in the system can be considered. Due to existence of the interferer, an even-power-allocation scheme is not guaranteed to be optimal even for a single user. For example, consider a user in the cell boundary, e.g., η≈1. In this case, an even-power-allocation leads to approximately zero SNR and further limit the sum rate for this user, if the system allocates all the resources to him, by 2 bits per second, according to (14). However, all the power is assigned to one of the carriers, e.g., choose (P1, P2)=(2 Pm, 0), this user will lose half of the degrees of freedom and obtain a power gain on the carrier in use. Due to the concavity of capacity formulation, when the interference does not change, it is beneficial to use more degrees of freedom rather than focusing the power on part of the bandwidth. However, at the presence of an interferer, it is possible that the power gain can dominate the loss in degrees of freedom. Specifically, using the formulation in (14), the SNR under a (2 Pm, 0) allocation is h2P2. In an interference limited scenario, we have h2P2>>1. Apparently, in this case, a capacity gain for certain users can be obtained by allowing power allocation to deviate from the even-power-allocation scheme. In particular, the maximum capacity of a single user in the two-cell system can be evaluated as follows. Single user capacity with two carriers: The following problem can be analyzed: what is the optimal power allocation scheme in the presence of a cooperative interferer for a given user? The following lemma answers this question. Lemma 2: The optimal power allocation scheme for a mobile parameterized by channel gain h and path-loss ratio η (the subscript can be removed in this lemma since all resources can be scheduled to a single user in the primary cell) is either a reuse-1 or a reuse-2 scheme, e.g., (Pm, Pm) or (2Pm, 0). Proof: To see this, the sum capacity (over the two carriers) of a user under a power allocation scheme (Pm+x, Pm−x) can be represented as a function of x, which is the amount of power chosen to deviate from the even-allocation method: C ( x ) = log 2 ( 1 + h ( P m + x ) 1 + η h ( P m - x ) ) + log 2 ( 1 + h ( P m - x ) 1 + η h ( P m + x ) ) . C(x) can be maximized for xε[−Pm, Pm] when x=0, x=Pm, or x=−Pm. Since C(x)=C(−x), it suffices to show that C(x) is either monotonely decreasing or increasing within the interval xε[0, Pm]. To see this, the first-order derivative of C(x) with respect to x can be evaluated such that C ′ ( x ) = 1 ln ( 2 ) { 1 x + z 1 - 1 z 1 - x - 1 x + z 2 + 1 z 2 - x } , ( 9 ) where the poles z1 and z2 are defined below z 1 = P m + 1 + 2 η hP m ( 1 - η ) h ; ( 10 ) z 2 = P m + 1 η h . ( 11 ) It can be determined that z1, z2>Pm. Given xε[−Pm, Pm], the four terms (without sign) in (9) are all positive. Further, if z1>z2, then C′(x)>0 for all xε[0, Pm] while if z1≦z2, then C′(x)<0. The condition for z1>z2 in the proof above is hP m > 1 - 2 η 2 η 2 . ( 12 ) In other words, for users satisfying (12), the optimal power allocation scheme is reuse 2. On the other hand, for mobiles that cannot satisfy (12), the optimal power allocation scheme is reuse 1. There are two observations that can be derived from this condition: (1) Given a power constraint Pm at the base station, mobiles with worse path loss ratio are more likely to benefit from a reuse-2 allocation; and (2) Given a mobile constrained by h and η, it is more likely for this mobile to benefit from a reuse-2 allocation in a base station with higher power constraint. Simply put, reuse-2 allocation is more favorable for an interference-limited deployment with a lot of cell-boundary mobiles. Two user capacity region: As before, the capacity region of two users under a given power allocation vector (P1, P2) in the primary cell can be considered. As utilized above, a power allocation can be (P1, P2) or (P2, P1) in the interferer cell. (P1, P2) in the interferer may not be an interesting scenario since in this case, in the interference-limited deployment, the performance can be quite similar to the simple reuse 1 scheme. Thus, the capacity region under power allocation (P1, P2) at the primary and (P2, P1) at the interferer can be evaluated. Theorem 3: Assume the path-loss gains for the two users in the primary cell are h1, h2 and satisfy h2≧h1. Assume the path loss ratio η1, η2 satisfy η1≧η2. The capacity region under a fixed power allocation scheme (P1, P2) (P2≧P1) is the convex hull of four capacity vectors (0, 0), (R1, 0), (0, R2), and (R′1, R′2), where R1, R2, R′1, and R′2 are defined below. R 1 = log 2 ( 1 + h 1 P 1 1 + η 1 h 1 P 2 ) + log 2 ( 1 + h 1 P 2 1 + η 1 h 1 P 1 ) ; ( 13 ) R 2 = log 2 ( 1 + h 2 P 1 1 + η 2 h 2 P 2 ) + log 2 ( 1 + h 2 P 2 1 + η 2 h 2 P 1 ) ; ( 14 ) R 1 ′ = log 2 ( 1 + h 1 P 2 1 + η 1 h 1 P 1 ) ; ( 15 ) R 2 ′ = log 2 ( 1 + h 2 P 1 1 + η 2 h 2 P 2 ) . ( 16 ) Proof: The proof is similar to the proof to Theorem 1. Remarks: Ri (i=1, 2) can be the capacity when both carriers are assigned to user i and (R′1, R′2) can be the rate tuple when the good user is scheduled to the bad carrier and the bad user is scheduled to the good carrier. The capacity region of an arbitrary power allocation method can be compared to the capacity regions under reuse 1 and reuse 2 scheme. For simplicity, the case where a good user and a bad user coexist in the primary cell can be evaluated. However, it should be noted that the definition of good and bad is different than the ones used in the single cell case. In the single cell case, there is no clear constraint to quantize how good a user is and the words good and bad come from the relative channel quality comparison between the two users. Here, a bad user can be a user with an h and q such that (12) is satisfied while a good user can be a user such that (12) is not satisfied. FIG. 18 illustrates example capacity regions under such an assumption. Referring to FIG. 18, illustrated is an example of capacity regions for a two-user two-carrier two-cell system under reuse-1, reuse-2 and a (P1, P2) allocation. At 1802, a reuse-1 capacity region is illustrated. At 1804, a reuse-2 capacity region is shown. Further, at 1806, a (P1, P2) capacity region is depicted. Moreover, 1808 represents an achievability regions under all power allocation schemes. As shown in FIG. 18, the good user's rate is maximized in a reuse-1 scheme while the bad user's rate is maximized in reuse-2 scheme. For a general (P1, P2) allocation, the capacity region is again a convex region characterized by Theorem 3. Further, the set of achievable rate tuples under any power allocation scheme can be analyzed. This achievable region can be the union of the capacity regions under all power allocation schemes and is also shown at 1808. For any rate tuple within this achievable region, a power allocation scheme and a scheduling policy to achieve this rate tuple can be determined. However, it is to be appreciated that this region is not necessarily a convex region. Opportunistic power allocation: Schemes to improve upon the rate regions achieved in FIG. 18 can leverage introducing time-varying power allocation scheme. Due to the non-convexity of the rate region by the fixed power allocation scheme, the region can be improved by time-sharing between different power allocation schemes. An example is to time-share with reuse-1 and reuse-2, which can effectuate achieving a linear region connecting the point (R1, 0) and (0, R′2). Further, similar to the single cell case, after introducing time-variation, there is not much difference between a single-carrier system and a multi-carrier system, from a spectral efficiency point of view. Thus, the capacity region under an average power constraint when a corporative interferer exists can be evaluated as described below. A single-carrier two-cell can be utilized according to an example. At each time slot, the scheduler can pick one user to transmit and a power level to transmit under an average power constraint. Again, to maximize the throughput in the primary cell, the interference cell can shut down completely. Here, again a symmetry assumption can be utilized. Specifically, both cells can be assumed to have to choose from the same power alphabet. A power alphabet is a set of discrete power levels that a cell is allowed to choose from at a given time slot. Assuming the power alphabet is P1, P2, . . . , PL, we define a matrix π={πij}, 1≦i,j≦L, where πij represents the time fraction that the primary cell chooses power level Pi while the interferer chooses Pj. Assuming symmetry can enforce that πij=πji. Single user capacity under opportunistic power allocation: The capacity for a single user in the primary cell can be reviewed. When the interferer does not exist, or the interferer chooses a even-power-allocation scheme, e.g., interferer is incorporative, the strategy for the primary cell is also to use an even-power-allocation scheme. However, when a corporative interferer exists, the problem is not well understood even for a single user. The study of the single user capacity will also lead to the end-points in the capacity region when more than one user exist in the primary cell and give insight into the multiuser problem. The single-user capacity problem can be formulated as below: max P , π ∑ ij π ij C ij ( 17 ) s . t . ∑ ij π ij = 1 ; ( 18 ) ∑ ij π ij P i = P m ; ( 19 ) 0 ≤ π ij ≤ 1 , ∀ i , j ; ( 20 ) π ij = π ji , ( 21 ) where Cij is the capacity of the user, (characterized by h and η), when the primary cell chooses Pi and the interferer chooses Pj. For simplicity, again the AWGN Shannon capacity formula can be utilized and C ij = log 2 ( 1 + hP i 1 + η h P j ) . ( 22 ) The constraints (18) and (20) come from the definition of π. Constraint (19) follows from the average power constraint, and (21) is a consequence of the symmetry assumption. This problem is an extension to the two-carrier problem considered above. Actually, to vary power in time has no essential difference to vary power in the frequency domain, except that since time goes on forever, a finer allocation (or time-sharing) between different schemes can be obtained. If the system can have infinite number of carriers, the problem to find the optimal power allocation across carriers is substantially similar to the problem to find the optimal power allocation in time. Theorem 4: The maximum rate for a single user under the opportunistic power allocation is determined by the solution to the following optimization problem max θ 1 log 2 ( 1 + hP 1 1 + η h P 1 ) + θ 2 log 2 ( 1 + 2 h P 2 ) 2 ( 23 ) s . t . θ 1 + θ 2 = 1 ; ( 24 ) θ 1 P 1 + θ 2 P 2 = P m ; ( 25 ) 0 ≤ θ 1 , θ 2 ≤ 1. ( 26 ) Remarks: As compared to the original infinite-dimensional optimization problem (17), the optimization problem here can be simpler. In (23), the optimization has four parameters θ1, θ2, P1 and P2, and can be interpreted as follows. The optimization (23) is essentially a time/power sharing between reuse-1 and reuse-2 scheme. θ1 and θ2 correspond to the time fraction that the system is choosing reuse-1 and reuse-2 schemes, respectively. P1 and P2 are the power levels the system chooses for reuse-1 and reuse-2, given the average power constraint can be satisfied. In other words, this theorem reveals that among all possible power allocation strategies, for any single mobile in the system, the optimal strategy to optimize its capacity within the system can be in the form of time/power sharing between reuse-1 and reuse-2. It should be noted here the time/power sharing here is different from the time/power sharing scheme mentioned in the single cell case since there the sharing is between users while here the resource is shared among different transmitting strategies for the same user. Proof: To prove this theorem, (17) can be optimized over all possible probability matrix π given a fixed set of power alphabet. After fixing P, it can be seen that Cij's are constant with respect to π and the problem (17) becomes a linear programming problem. Next the constraint (21) can be removed by reducing the number of parameters to optimize. max { π ij : i ≥ j } ∑ i ≥ j π ij ( C ij + C ji I i ≠ j ) ( 27 ) s . t . ∑ i ≥ j π ij ( 1 + I i ≠ j ) = 1 ; ( 28 ) ∑ i ≥ j π ij P i = P m ; ( 29 ) 0 ≤ π ij ≤ 1 , ∀ i , j , ( 30 ) where Ii≠j is the indicator function that i is not equal to j. Another observation that can be made is that (28) already ensures that πij≦1, given that πij≧0, for all i,j. Thus, the linear constraints can be now reduced to ∑ i ≥ j π ij ( 1 + I i ≠ j ) = 1 ; ( 31 ) ∑ i ≥ j π ij P i = P m ; ( 32 ) πij≧0,∀i,j. (33) Since the linear programming problem is optimized at one of the vertexes of the linear region, the vertexes of the region determined by (31)-(33) can be reviewed. For instance, optimizing {πij: i≧j} can have at most two non-zero entries. It can be shown that the above is true if there are three πij's (i≧j) to optimize over. In the three-dimensional space, the two constraints (31) and (32) restrict the feasible πij's to be on a straight line. Thus, the vertexes of the convex region are nothing but the endpoints of the straight line when it hits one of the three plains: πij=0. (It has to hit the plains since the whole region is a bounded region.) Thus, one of the three parameters have to be zero, which proves the above for the case of three πij's. For the general case, this argument can be applied to any non-zero three πij's and shown that it does not reduce the optimality by considering only two out of three πij's to be non-zero. Therefore, for any power alphabet of any size, it does not lose any optimality by only assigning the probability to up to four power levels. Further, in the upper half (including the diagonal entries), it is sufficient to consider only two non-zero πij entries. With this simplification, three cases can be evaluated: (i) both non-zero entries are not diagonal entries; (ii) one of the entries is a diagonal entry; and (iii) both entries are diagonal entries. However, in the case of (ii) and (iii), it can be considered as a special case of (i) by allowing the power alphabet to have identical entries. In view of this, the power alphabet can be assumed to be (P1, P2, P3, P4), and the non-zero probability entries are π12, π21 and π34, π43. Lemma 2 can be applied here and further it can be determined that P1=P2 or one of P1, P2=0. In particular, the choice of P1 and P2 can be optimized, without changing the average of them, which can yield the same problem as the two-carrier two-cell single-user problem seen above, and thus, Lemma 2 is applicable here. Same argument holds for P3 and P4. In other words, both (P1, P2) and (P3, P4) are either reuse-1 or reuse-2. On the other hand, if both of them belong to the same reuse scheme, either reuse-1 or reuse-2, there may be no motivation to choose different power levels. This can be for reuse-2; for reuse-1, on the other hand, the concavity of the following function can be argued: log2 ( 1 + x 1 + ax ) , which can be straightforward when evaluating the second-order derivative with respect to x. A numerical solution to the optimization problem in (23) can also be provided. The solution is summarized in the following corollary. Corollary 2: The capacity of a single user under opportunistic power allocation with average power Pm, or equivalently, the solution to the optimization problem (17), is determined by the following equation: C ( P m ) = { log 2 ( 1 + hP m 1 + η h P m ) if P m < P T 1 ; P m - P T 1 P T 2 - P T 1 log 2 ( 1 + hP T 1 1 + η h P T 1 ) + P T 2 - P m P T 2 - P T 1 1 2 log 2 ( 1 + 2 hP T 2 ) if P T 1 ≤ P m < P T 2 ; 1 2 log 2 ( 1 + 2 h P m ) i f P m ≥ P T 2 . ( 34 ) where PT1 and PT2 are defined in FIG. 19. FIG. 19 illustrates a solution to the single user power allocation problem. As depicted, 1902 illustrates capacity under reuse 2, 1904 shows capacity under reuse 1, 1906 illustrates a common tangential line, and 1908 represents a capacity. The line 1904 is the capacity with average power Pm under reuse 1, which is given by log 2 ( 1 + hP m 1 + η h P m ) . The line 1902 is the capacity under reuse 2, which is given by ½ log2(1+2hPm). The dashed line 1906 is a straight line which is tangential to both capacity curves. PT1 and PT2 are the tangential points of the common tangential line to the two capacity curves. Again referring to FIG. 19, in the lower SNR regime, the reuse-1 curve 1904 performs similar as compared to the reuse-2 capacity curve 1902 since in the low SNR regime, the capacity scales linearly with the transmit power regardless the how many degrees of freedom are used. However, as available power grows, reuse-1 starts to outperform reuse-2 since the optimal strategy generally is to spread the available power evenly across bandwidth. However, due to the existence of the interferer, the reuse-1 capacity will be bounded by log2 ( 1 + 1 α ) as SNR grows while the reuse-2 SNR keeps growing logarithmatically. This solution illustrates that when the available power Pm is less than PT1, which is determined given h and η for a mobile, then reuse-1 is optimal. If the average power is larger than the other threshold PT2, then reuse-2 is optimal, where the transmitter transmits at 2 Pm half of the time and keeps silent in the other half degrees of freedom. When the average power Pm falls between the two thresholds, then a time/power sharing between reuse-1 and reuse-2 is optimal. Further, when doing reuse-1, the transmitter should transmit at power PT1; when doing reuse-2, the transmitter should transmit at power 2PT2 when it is transmitting. This illustrates the optimal transmitting strategy at a given power level. An alternate angle to look at this problem is to find the optimal transmitting strategy for different mobiles (with different h and η) given an average power constraint. For the mobiles which are close to the transmitter, e.g., η<<1, the hard limit for the rate in reuse-1 case is very large and the intersection point PT can be out of the power range of interest. In this case, reuse-1 can be optimal for a power constraint. On the other hand, for cell boundary users, e.g., η is comparable to, in this case, the reuse-1 curve can be compressed into a small capacity region between 0 and probably a couple of bits per second. In this case, the threshold power levels are moved to close to 0 and for any reasonable power constraint, reuse-2 is optimal, among possible transmitting strategies. A relation exists between Corollary 2 and Lemma 2. Lemma 2 focused on the scenario where the system has two carriers and discussed the best way to allocate power between the two carriers to maximize the rate for a single user in the primary cell. This is equivalent to find the optimal opportunistic power allocation scheme if restricted to a power alphabet size of 2 and a probability matrix with zero diagonal entries. It shows that there is a single threshold for the average power P T = 1 - 2 α 2 h α 2 such that if Pm>Pt, reuse-2 is optimal and otherwise reuse-1 is optimal. It can be seen that PT corresponds to the intersection point of reuse-1 and reuse-2 capacity curves in FIG. 19. Thus, removing the constraints on the alphabet size and the probability matrix above helps improve the capacity for Pmε(PT1, PT2). Proof: Achievability is trivial if the above transmitting strategy is employed. For the converse, Theorem 4 has narrowed down the optimal transmitting strategy to a much smaller set of strategies as described in (23). Thus, it can be shown that by doing time/power sharing between reuse-1 and reuse-2, better results than curve 1908 may not be obtained. This is again true since any achievable rate tuple under time/power sharing between reuse-1 and reuse-2 lies on one of the straight lines connecting two points: one on the reuse-1 curve and the other on the reuse-2 curve. Capacity region under opportunistic power allocation: The capacity region for two users in the primary cell under opportunistic power allocation can be analyzed. An achievability region can be shown which improves upon the capacity region depicted in FIG. 18. This region roughly estimates the improvement that can be yielded as compared to the capacity region under simple reuse-1 schemes. A strategy is to do time-sharing between reuse-1 and reuse-2. This will achieve a capacity region for rate tuples under a straight line connecting the two extreme points under reuse-1 and reuse-2 in FIG. 18. This linear region can be further improved by using the same strategy as used for the single user scenario, e.g., do time/power sharing between reuse 1 and reuse 2. By doing this, the achievable rate region can be characterized as the following lemma. Lemma 3: For a single-carrier two-cell system, assume that the two users in the primary cell are characterized by (h1, η1) (h2, η2) and satisfy that h2≧h1 and η2≦η1, e.g., user 1 is a good user and user 2 is a bad user. The capacity region for these two users is lower bounded by the following rate region { ( θ log 2 ( 1 + 2 h 1 P 1 ) 2 , ( 1 - θ ) log 2 ( 1 + h 2 P 2 1 + α 2 h 2 P 2 ) ) : 0 ≤ θ ≤ 1 , θ P 1 + ( 1 - θ ) P 2 = P m } . The achievable rate region can be compared to the simple reuse-1 and reuse-2 scheme. As shown in FIG. 20, the region is a superset to either the reuse-1 or reuse-2 scheme. FIG. 20 illustrates an achievable rate region under opportunistic power allocation. Moreover, line 2002 represents a reuse-1 capacity region, line 2004 depicts a reuse-2 capacity region, line 2006 illustrates time sharing between reuse-1 and reuse-2, line 2008 depicts time/power sharing between reuse-1 and reuse-2, and line 2010 illustrates time/power sharing between reuse-1 and (P1, P2). The achievable rate region can be superior to the region based on time-sharing between reuse-1 and reuse-2 too by giving another freedom to share power as well. Thus, by doing this scheme, capacity gain can be achieved against the traditional reuse-1 scheme. By using a time/power sharing between reuse-1 and reuse-2, a restriction to a power alphabet of size 3, with one the alphabet being 0, can be utilized. However, it is not clear a priori that such choices are optimal or close to optimal in the case of multiple users although it can be known that they are optimal in the single-user scenario. Next it can be shown that for the two user case, to consider a power level alphabet of size 4 is sufficient. Theorem 5: Every rate tuple within the capacity region for the two users in a two-cell system under opportunistic power allocation can be achieved by a power allocation scheme with a power level alphabet of size 4. Proof: Apparently, it suffices to show that the statement is true for all rate tuple on the boundary of the capacity region. First, the capacity region can be a convex region under opportunistic power allocation. This is true since any two rate tuples within the capacity region, a simple time-sharing strategy can achieve all rate tuples on the straight line connecting these two tuples. In other words, they are within the capacity region as well, which shows the convexity of the region. An important property for a convex region is that for any point lying on the boundary of the region, a tangential straight line can be found such that the whole region is on one side of the straight line. Thus, for any point (R1, R2) on the boundary, a set of linear parameters w1 and w2 can be found such that (R1, R2) is the solution to the following optimization problem: max w1R1+w2R2 (35) s.t.(R1,R2)εΛ, (36) if Λ denotes the capacity region under opportunistic power allocation. Further, this problem can be written more explicitly as follows: max P , π , β ∑ ij π ij ( w 1 β ij log 2 ( 1 + h 1 P i 1 + η 1 h 1 P j ) + w 2 ( 1 - β ) log 2 ( 1 + h 2 P i 1 + η 2 h 2 P j ) ) ( 37 ) s . t . ∑ ij π ij = 1 ; ( 38 ) ∑ ij π ij P i = P m ; ( 39 ) 0≦πij≦1,∀i,j; (40) πij=πji; (41) 0≦βij≦1,∀i,j. (42) The optimization over {βij} given the power allocation alphabet P and the joint probability matrix {πij} is trivial. From (37), it can be apparent to assign the user with better weighted capacity in state πij. Thus, the objective function (37) can be simplified to max P , π ∑ ij π ij ( max ( w 1 log 2 ( 1 + h 1 P i 1 + η 1 h 1 P j ) , w 2 log 2 ( 1 + h 2 P i 1 + η 2 h 2 P j ) ) ) . Optimization over π given any set of alphabet P can be considered. This is again a linear programming problem and the argument used in the proof of Theorem 4 can be employed. A conclusion can be reached that optimality is not lost by focusing on alphabets with size 4 and the corresponding joint probability matrix with at most four non-zero entries: π12, π21, π34, π43. By trying all possible choices of P, π and all possible scheduling policies under this constraint, the whole capacity region can be achieved. Remarks: Although Theorem 5 does not provide a closed-form expression for the capacity region, it significantly reduces the complexity of the original optimization problem (37) to an optimization problem with eight parameters. On the other hand, it also shows that the time/power sharing between reuse-1 and reuse-2 can not be too far away from the optimal capacity region since in general, any point within the capacity region should be able to be achieved by time/power sharing with two general reuse schemes: (P1, P2) and (P3, P4). A conjecture that can be made is that one of the reuse schemes should be the reuse-1 scheme, e.g., P3=P4. Thus, a better scheme which might outperform time/power sharing between reuse-1 and reuse-2 is to do time/power sharing between reuse-1 and (P1, P2). An advantage of this scheme can be significant especially when P2 is chosen to be a small power instead of zero. Of course, according to the scheduling guideline observed herein, the good user can be scheduled in this close-to-zero carrier. By doing this, the available degrees for the good users can be increased by taking a small hit on the SNR of the bad users scheduled in P1. Overall, better points can be achieved as compared to the capacity region under time/power sharing between reuse-1 and reuse-2. This observation is also shown in FIG. 20. All the curves shown in FIG. 20 can be achievable curves under certain power reuse schemes in the time domain or the frequency domain. The benefit of doing this now can be significant. For all or nearly all practical systems, the operating point won't sit on the end point of (0, R2). For any other operating point, an improvement can be provided by using smarter power reuse schemes than the simple reuse-1 scheme. The more cell-edge users in the system, the more benefit obtained. Moreover, this improvement won't go away even when the one-user-per-slot constraint is removed. In other words, in multi-cell scenario, a good design within the carrier is not sufficient to take good care of the inter-cell interference. Collaboration in different carriers/time slots and joint power allocation and scheduling can improve the performance of all types of users in the system. Breathing cells: opportunistic power allocation in the multi-cell scenario. The above theoretic analysis can indicate that varying power across time and/or frequency is beneficial for the overall system performance, without introducing too much complexity to the system. Further, scheduling can be done in such a way that good users are mostly scheduled in the bad carriers/time-slots, while the bad users are mostly scheduled in the good carriers/time-slots. In the single cell scenario, the gain by doing this is not so significant. On the other hand, the potential gain by doing this scheme when inter-cell interference exists can be very important since now for the cell boundary users, the power gain can now easily compensate for the loss in segments. This benefit can be seen in the capacity region comparison as shown above. In a typical multi-cell cellular deployment, around thirty percent of the users can have an average SNR below 0 dB due to the inter-cell interference. This plays a key bottleneck to the system performance for both data and delay-sensitive applications. Thus, one would expect that similar schemes can be utilized to smartly reuse power across carriers or time to improve the system spectral efficiency. Accordingly, a scheme can be leveraged to extend the intuitions achieved in the single-cell and two-cell cases to the multi-cell scenarios, and qualitatively analyze the potential gain that can be achieved by introducing these schemes in the current cellular networks. Power allocation patterns and their reuse over the network: The scheme proposed here is called the breathing-cell scheme, where each cell varies its transmit power limit in a slow pace (as compared to the communication time scale), and in a cooperative way, e.g., a cell transmits at high power when the others are transmitting at relatively low power. An example is shown in FIG. 12. In this example, each cell varies its power between −Pm and Pm with a period of 100 time slots. For adjacent cells, they choose different power level types to create fluctuations in SNRs, as shown in FIG. 10. A slow-time-scale power variation can be chosen since in a practical system, it may not desirable to have the power varying too rapidly because of the following considerations: (1) the mobile can have difficulty to track the channel variation if the power varies too fast; and (2) it is not desirable to require too much synchronization between different base stations. Scheduling in breathing cells: With this opportunistic power allocation scheme, stationary users in the system can see channel fluctuations. However, the channel fluctuations are highly correlated across users. For example, when the cell's allocated power curve goes up, and the neighboring cells' power goes down, all users within the cell will see channel quality improvement. Similar to the above observations, in such scenarios, a good way is to schedule a good user when the channel is bad and to schedule a bad user when the channel is good. In the two user case, this guideline is simple enough to implement. However, in the more interesting multi-user scenario, it is not that straight forward to find a simple scheduling rule to choose user wisely and fairly. The proportional-fair scheduler can solve this problem. In the proportional-fair scheduler, the scheduler picks user k* in each time slot with the largest Rk(t)/Tk(t), where Rk(t) is the estimated rate that user k can transmit if scheduled based on its SNR report and Tk(t) is the average throughput of user k in history. In implementations, Tk(t) can be calculated over a comparatively long sliding window as compared to the communication scale, since the channel of a moving user can be non-ergotic. The window size also reflects the maximum tolerable delay in scheduling. This scheduler can be shown to maximize the system utility of Σk log(Tk), where Tk is the long-term average throughput of user k. In the case of symmetric user channel conditions, e.g., the distribution of the channel conditions between users can be substantially similar, and the proportional fair scheduler can pick the user with the best channel condition. Thus, all users will be picked when their channel conditions are relatively good as compared to the average levels and the more users in the system, the better chance that a user will be picked at its best possible channel. From a system point of view, it looks like the system's sum throughput is increasing as the number of users are increasing and this phenomena is referred to as the multi-user diversity. With multi-user diversity, tractable channel fading/variations can actually bring benefit to the system. However, in breathing cells, the proportional fair scheduler behaves differently. First of all, the channel quality of users is highly correlated assuming users are stationary and the channel quality is fully determined by the power allocation variation across time. FIG. 21 and FIG. 22 show the channel condition and normalized schedulable rate for different users in the breathing-cell scheme. In particular, FIG. 21 illustrates channel conditions for two users within the same cell under breathing cells where both channel gains can be normalized by the average channel gain of the good user. Further, FIG. 22 illustrates variations of Rk/Tk for different users. FIG. 22 can provide information about how a proportional fair scheduler picks users in a particular case. Again, due to the concavity of capacity, when the channel condition improves for both users, the effect for the bad user is more important in terms of Rk/Tk; when the channel condition deteriorates, the good user takes a lower decrease in Rk/Tk. As a consequence, the scheduler picks the good user when the channel is bad and picks the bad user when the channel is good. Another salient feature of the breathing-cell design is that the inter-cell interferences experienced by different users are not synchronized in a multi-cell scenario. This can be because the main interfering cells to users at different locations are breathing with different patterns. This adds another degree of variations to the curve of Rk/Tk as shown in FIG. 22. Thus, in different time slots, the scheduler can favor the users experiencing less inter-cell interference. Delay-sensitive applications: An issue of the breathing-cell design can be related to performance associated with delay-sensitive traffic. In such case, the system does not have so much freedom to schedule the traffic in terms of waiting for the right moment. By artificially introducing channel fluctuations to all the users, long outage periods can be introduced for cell boundary users. Accordingly, extensions of this design can address this issue. In a multi-carrier system, a possible remedy is to reuse the power variation pattern across carriers too. For example, suppose there are three carriers per cell. A power allocation pattern can be assigned and as a consequence, at each time slot, there can be at least one carrier having better SNR as compared to the simple Reuse-1 scheme. The scheduler gives priority to the delay-sensitive traffic over the elastic traffic and first schedules them to be transmitted over the channel. It can be noted that it may not always be beneficial to schedule the delay sensitive traffic on the best carrier at the moment since it might cause left-overs for the best carrier and reduce the possible benefit for the elastic traffic. A guideline can be to schedule the delay sensitive traffic on the worst carrier(s) which are capable of depleting the delay-sensitive queue. Such an extension can be utilized when all mobiles, including delay-sensitive mobiles, are wideband mobiles. This assumption might not be true for VOIP type of mobile. For a multi-carrier system with a lot of narrow-band delay-sensitive mobiles, another system design can be to do the fixed power reuse approach instead of the breathing-cell scheme. If the number of carriers within each cell is large, there may be no difference between vary the power across time or across carriers. The same power level variation levels can be assigned as the power-allocation schemes over multiple carriers. In the case of three carriers per sector, this leads to Flexband design. In this case, the scheduler problem for delay-sensitive users is partly shifted to the admission controller. A similar rule to the scheduling guideline mentioned above can be applied here such that a delay-sensitive mobile is admitted to the worst qualified carrier, which is capable of deliver the traffic from the mobile without causing outage. On the other hand, the other wideband data mobiles can still take advantage of a similar benefit as seen in breathing cells. The single-carrier network with delay-sensitive users can be considered. In this case, apparently, none of the schemes seen above may help if slow variation over transmit power is adopted in all the cells. In this case, actually, a TDD-type of design can at least mitigate the problem that the breathing-cell design causes for delay-sensitive users. The TDD here is not between uplink and downlink, but between different transmit modes determined by transmit power. For example, one can choose three different power levels and each cell chooses a specific order of iterating these three power levels. For elastic users, the benefit of doing this is similar to the Flexband design with three carriers each cell. For delay sensitive users, the outage period is much shorter now as compared to the breathing-cell design. However, this scheme leverages global synchronization, which is available in TDD networks, but not in FDD networks. Also, this introduces more complexity to the system. For example, the scheduler has to track three different SNR levels for all mobiles to make the scheduling decision. Comparison to opportunistic beamforming: There is similarity between this scheme and the opportunistic beamforming scheme utilized for a multiple antenna downlink. In opportunistic beamforming, the base station uses multiple antennas to form one or multiple beams and sweeps across the users within the cell. This is done by varying the power and phase for the signals fed into different antennas in a slow time scale. Comparing the two schemes, there are a lot of similarities. First, both schemes try to introduce trackable channel fluctuations to stationary channels so that the system can benefit from multiuser diversity. Second, they both have problems in dealing with delay-sensitive traffic. However, the approaches proposed above also can be used for opportunistic beam-forming with slight modifications. Finally, the gain from opportunistic beam-forming will disappear if all channels are Rayleigh-faded. The breathing-cell design also suffers from Rayleigh-faded channel since in that case, the multi-user diversity boosts the SNR of all users at the times of being scheduled. The gain of the breathing-cell design mainly comes from the fact that the power gain can be translated to a better capacity gain for poor users in the reuse-1 scheme. However, the multi-user diversity caused by fading channels makes everyone a better user and thus reduces the potential gain we can achieve through breathing cells. However, there are also some differences between the two schemes: (1) Multiple antennas are not required to achieve the capacity gain in breathing cells. Thus the system complexity is much less as compared to the system with opportunistic beamforming. (2) The gain of breathing cells is more significant when multiple cells exists. The opportunistic beamforming can see most of its gain even with a single cell. (3) The gain of breathing cells can only be seen when each cell has mobiles with different SNRs. This is a valid assumption in a loaded system. However, when all the mobiles are close-to-base station mobiles, breathing cells can actually lead to a capacity loss. On the other hand, the opportunistic beamforming can still see a substantial gain when the SNRs of all mobiles are similar. The constraint there, though, is that the mobiles have to differ in angular directions. As a summary, the breathing-cell approach differentiates users according to their distance to the base station, while the opportunistic beamforming mainly differentiates mobiles with different em angular direction. (4) The scheduler behaves differently in breathing cells. Here, it is not possible to schedule all the users at their peaks. On the contrary, for the good users, the scheduler prefers to schedule them in bad channel conditions. Of course, they can be scheduled much more often in breathing cells as compared to the reuse-1 case since a lot of resources are saved by scheduling. Referring to FIGS. 23-25, methodologies relating to power allocation in a wireless communication network are illustrated. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more embodiments. Turning to FIG. 23, illustrated is a methodology 2300 that facilitates operating a communication network including a wireless communication base station that includes a first sector. At 2302, a first channel can be transmitted on at a first power level from the first sector during a first time period based on a first predetermined pattern (e.g., power allocation pattern). Further, the first channel can include a first frequency bandwidth (e.g., carrier). At 2304, the first channel can be transmitted on at a second power level from the first sector during a second time period based on the first predetermined pattern. Moreover, the second power level can be at least 0.5 dB different from the first power level. The transmissions can occur upon a single carrier; however, it is contemplated that multiple carriers can be utilized. Moreover, according to another example, channel quality report(s) can be received from one or more mobile devices and based upon these reports the first channel can be scheduled; thus, the first channel can be transmitted upon to the one or more mobile devices. Pursuant to an illustration, the first sector and a second sector can be included in a common cell; thus, a sector-wise reuse scheme can be leveraged. According to another embodiment (e.g., cell-wise reuse), the first sector can be included in a first cell, where disparate sector(s) of the first cell enable transmitting at substantially similar power levels as the first sector during each time period, and a second sector can be included in a second cell, where differing sector(s) of the second cell allow transmitting at substantially similar power levels as the second sector during each time period. It is contemplated that the transmissions can be assigned according to a scheme that can coordinate sectors and/or cells to enhance spectral efficiency. For example, the scheme can leverage discrete power levels that can be allotted in a time division manner. According to another illustration, respective smooth power allocation pattern curves can be allocated to the first sector and the second sector; these smooth power allocation pattern curves can set forth the power level for the sector as a function of time. By way of further illustration, the first wireless communication base station can include a second sector. As such, a second channel can be transmitted on at a third power level from the second sector during the first time period based on a second predetermined pattern. Further, the second channel can include a second frequency bandwidth, where the first frequency bandwidth and the second frequency bandwidth can have at least 50% frequency bandwidth in common (e.g., a single carrier can be employed). Moreover, the second channel can be transmitted on at a fourth power level from the second sector during the second time period based on the second predetermined pattern. The fourth power level, for instance, can be at least 0.5 dB different from the third power level. Additionally, the first power level can be within 0.5 dB of the third power level and the second power level can be within 0.5 dB of the fourth power level. According to another example, it is to be appreciated that the first predetermined pattern and the second predetermined pattern can be substantially similar. Pursuant to another example, the communication network can include a second wireless communication base station that can include the second sector described above. Accordingly, the first power level can be at least 0.5 dB greater than the third power level, while the second power level can be at least 0.5 dB less than the fourth power level. Moreover, the first predetermined pattern and the second predetermined pattern can both be periodical. It is to be appreciated that these predetermined patterns can have dissimilar periods and/or substantially similar periods. Further, the first and second predetermined patterns can have substantially similar periods with differing phases. Turning to FIG. 24, illustrated is a methodology 2400 that facilitates adaptively assigning power allocation patterns for allocating power levels. At 2402, an adaptive power allocation pattern can be selected based upon load information. For instance, load information can be shared amongst sector(s) and/or cell(s). Further, the load information can be leveraged to compare respective loads corresponding to each sector and/or cell. Power allocation patterns can be shifted to accommodate the analyzed loads; for example, a mean power level can be shifted up or down based upon a respective load. At 2404, power levels can be assigned as a function of time based upon the power allocation pattern. The power allocation pattern, for example, can be a sinusoidal curve that provides a power level as a function of time. At 2406, transmission can occur according to the assigned power levels. Now referring to FIG. 25, illustrated is a methodology 2500 that facilitates operating a multiple carrier communication network including a first wireless communication base station that includes a first sector. At 2502, a first channel can be transmitted on at a first power level from the first sector during a first time period based on a first predetermined pattern. For instance, the first channel can include a first frequency bandwidth. At 2504, the first channel can be transmitted on at a second power level from the first sector during a second time period based on the first predetermined pattern. At 2506, a second channel can be transmitted on at a third power level from the first sector during the first time period based on a second predetermined pattern. Further, the second channel can include a second frequency bandwidth. Moreover, the first frequency bandwidth and the second frequency bandwidth can be non-overlapping. At 2508, the second channel can be transmitted on at a fourth power level from the first sector during the second time period based on the second predetermined pattern. The second power level can be at least 0.5 dB different from the first power level and the fourth power level can be at least 0.5 dB different from the second power level. Additionally, a sum of the first power level and the third power level can be within 0.5 dB of a sum of the second power level and the fourth power level. Further, the first predetermined pattern and the second predetermined pattern can be periodical with substantially similar periods and disparate phases. Moreover, channel quality reports can be received from one or more mobile devices and transmission of the first channel and/or the second channel to the mobile device(s) can be scheduled as a function of the channel quality reports. According to another example, a second sector can also provide transmissions. The second sector can be included with the first sector in the first wireless communication base station. Alternatively, the second sector can be included in a second wireless communication base station. Moreover, a third channel can be transmitted on at a fifth power level from the second sector during the first time period based on a third predetermined pattern. The third channel can include a third frequency bandwidth that can have at least 50% frequency bandwidth in common with the first frequency bandwidth. Also, the third channel can be transmitted on at a sixth power level from the second sector during the second time period based on the third predetermined pattern. Additionally, a fourth channel can be transmitted on at a seventh power level from the second sector during the first time period based on a fourth predetermined pattern, where the fourth channel can include a fourth frequency bandwidth that does not overlap with the third frequency bandwidth in frequency. Further, the fourth frequency bandwidth can have at least 50% frequency bandwidth in common with the second frequency bandwidth. Moreover, the fourth channel can be transmitted on at an eighth power level from the second sector during the second time period based on the fourth predetermined pattern. These transmissions can be effectuated within a common sector. Moreover, it is contemplated that any number of sub-carriers can be supported by the common sector; the claimed subject matter is not limited to utilization of two sub-carriers. Further, it is to be appreciated that sector-wise or cell-wise reuse can be utilized in the wireless communication network. Additionally, the power levels can be allocated based upon a predetermined and/or adaptive scheme as described herein. It will be appreciated that, in accordance with one or more aspects described herein, inferences can be made regarding allocating power levels in a wireless communication network. As used herein, the term to “infer” or “inference” refers generally to the process of reasoning about or inferring states of the system, environment, and/or user from a set of observations as captured via events and/or data. Inference can be employed to identify a specific context or action, or can generate a probability distribution over states, for example. The inference can be probabilistic—that is, the computation of a probability distribution over states of interest based on a consideration of data and events. Inference can also refer to techniques employed for composing higher-level events from a set of events and/or data. Such inference results in the construction of new events or actions from a set of observed events and/or stored event data, whether or not the events are correlated in close temporal proximity, and whether the events and data come from one or several event and data sources. According to an example, one or more methods presented above can include making inferences pertaining to determining respectively loads encountered by neighboring sector(s) and/or cell(s). In accordance with another example, loading information can be leveraged to infer how to adapt power allocation patterns accordingly. It will be appreciated that the foregoing examples are illustrative in nature and are not intended to limit the number of inferences that can be made or the manner in which such inferences are made in conjunction with the various embodiments and/or methods described herein. FIG. 26 depicts an example communication system 2600 implemented in accordance with various aspects including multiple cells: cell I 2602, cell M 2604. Note that neighboring cells 2602, 2604 overlap slightly, as indicated by cell boundary region 2668. Each cell 2602, 2604 of system 2600 includes three sectors. Cells which have not been subdivided into multiple sectors (N=1), cells with two sectors (N=2) and cells with more than 3 sectors (N>3) are also possible in accordance with various aspects. Cell 2602 includes a first sector, sector I 2610, a second sector, sector II 2612, and a third sector, sector III 2614. Each sector 2610, 2612, 2614 has two sector boundary regions; each boundary region is shared between two adjacent sectors. Cell I 2602 includes a base station (BS), base station I 2606, and a plurality of end nodes (ENs) (e.g., wireless terminals) in each sector 2610, 2612, 2614. Sector I 2610 includes EN(1) 2636 and EN(X) 2638; sector II 2612 includes EN(1′) 2644 and EN(X′) 2646; sector III 2614 includes EN(1″) 2652 and EN(X″) 2654. Similarly, cell M 2604 includes base station M 2608, and a plurality of end nodes (ENs) in each sector 2622, 2624, 2626. Sector I 2622 includes EN(1) 2636′ and EN(X) 2638′; sector II 2624 includes EN(1′) 2644′ and EN(X′) 2646′; sector 3 2626 includes EN(1″) 2652′ and EN(X″) 2654′. System 2600 also includes a network node 2660 which is coupled to BS I 2606 and BS M 2608 via network links 2662, 2664, respectively. Network node 2660 is also coupled to other network nodes, e.g., other base stations, AAA server nodes, intermediate nodes, routers, etc. and the Internet via network link 2666. Network links 2662, 2664, 2666 may be, e.g., fiber optic cables. Each end node, e.g., EN(1) 2636 may be a wireless terminal including a transmitter as well as a receiver. The wireless terminals, e.g., EN(1) 2636 may move through system 2600 and may communicate via wireless links with the base station in the cell in which the EN is currently located. The wireless terminals, (WTs), e.g., EN(1) 2636, may communicate with peer nodes, e.g., other WTs in system 2600 or outside system 2600 via a base station, e.g., BS 2606, and/or network node 2660. WTs, e.g., EN(1) 2636 may be mobile communications devices such as cell phones, personal data assistants with wireless modems, etc. FIG. 27 illustrates an example base station 2700 in accordance with various aspects. Base station 2700 implements tone subset allocation sequences, with different tone subset allocation sequences generated for respective different sector types of the cell. Base station 2700 may be used as any one of base stations 2606, 2608 of the system 2600 of FIG. 26. The base station 2700 includes a receiver 2702, a transmitter 2704, a processor 2706, e.g., CPU, an input/output interface 2708 and memory 2710 coupled together by a bus 2709 over which various elements 2702, 2704, 2706, 2708, and 2710 may interchange data and information. Sectorized antenna 2703 coupled to receiver 2702 is used for receiving data and other signals, e.g., channel reports, from wireless terminals transmissions from each sector within the base station's cell. Sectorized antenna 2705 coupled to transmitter 2704 is used for transmitting data and other signals, e.g., control signals, pilot signal, beacon signals, etc. to wireless terminals 2800 (see FIG. 28) within each sector of the base station's cell. In various aspects, base station 2700 may employ multiple receivers 2702 and multiple transmitters 2704, e.g., an individual receiver 2702 for each sector and an individual transmitter 2704 for each sector. Processor 2706, may be, e.g., a general purpose central processing unit (CPU). Processor 2706 controls operation of base station 2700 under direction of one or more routines 2718 stored in memory 2710 and implements the methods. I/O interface 2708 provides a connection to other network nodes, coupling the BS 2700 to other base stations, access routers, AAA server nodes, etc., other networks, and the Internet. Memory 2710 includes routines 2718 and data/information 2720. Data/information 2720 includes data 2736, tone subset allocation sequence information 2738 including downlink strip-symbol time information 2740 and downlink tone information 2742, and wireless terminal (WT) data/info 2744 including a plurality of sets of WT information: WT 1 info 2746 and WT N info 2760. Each set of WT info, e.g., WT 1 info 2746 includes data 2748, terminal ID 2750, sector ID 2752, uplink channel information 2754, downlink channel information 2756, and mode information 2758. Routines 2718 include communications routines 2722 and base station control routines 2724. Base station control routines 2724 includes a scheduler module 2726 and signaling routines 2728 including a tone subset allocation routine 2730 for strip-symbol periods, other downlink tone allocation hopping routine 2732 for the rest of symbol periods, e.g., non strip-symbol periods, and a beacon routine 2734. Data 2736 includes data to be transmitted that will be sent to encoder 2714 of transmitter 2704 for encoding prior to transmission to WTs, and received data from WTs that has been processed through decoder 2712 of receiver 2702 following reception. Downlink strip-symbol time information 2740 includes the frame synchronization structure information, such as the superslot, beaconslot, and ultraslot structure information and information specifying whether a given symbol period is a strip-symbol period, and if so, the index of the strip-symbol period and whether the strip-symbol is a resetting point to truncate the tone subset allocation sequence used by the base station. Downlink tone information 2742 includes information including a carrier frequency assigned to the base station 2700, the number and frequency of tones, and the set of tone subsets to be allocated to the strip-symbol periods, and other cell and sector specific values such as slope, slope index and sector type. Data 2748 may include data that WT1 2800 has received from a peer node, data that WT1 2800 desires to be transmitted to a peer node, and downlink channel quality report feedback information. Terminal ID 2750 is a base station 2700 assigned ID that identifies WT 1 2800. Sector ID 2752 includes information identifying the sector in which WT1 2800 is operating. Sector ID 2752 can be used, for example, to determine the sector type. Uplink channel information 2754 includes information identifying channel segments that have been allocated by scheduler 2726 for WT1 2800 to use, e.g., uplink traffic channel segments for data, dedicated uplink control channels for requests, power control, timing control, etc. Each uplink channel assigned to WT1 2800 includes one or more logical tones, each logical tone following an uplink hopping sequence. Downlink channel information 2756 includes information identifying channel segments that have been allocated by scheduler 2726 to carry data and/or information to WT1 2800, e.g., downlink traffic channel segments for user data. Each downlink channel assigned to WT1 2800 includes one or more logical tones, each following a downlink hopping sequence. Mode information 2758 includes information identifying the state of operation of WT1 2800, e.g. sleep, hold, on. Communications routines 2722 control the base station 2700 to perform various communications operations and implement various communications protocols. Base station control routines 2724 are used to control the base station 2700 to perform basic base station functional tasks, e.g., signal generation and reception, scheduling, and to implement the steps of the method of some aspects including transmitting signals to wireless terminals using the tone subset allocation sequences during the strip-symbol periods. Signaling routine 2728 controls the operation of receiver 2702 with its decoder 2712 and transmitter 2704 with its encoder 2714. The signaling routine 2728 is responsible for controlling the generation of transmitted data 2736 and control information. Tone subset allocation routine 2730 constructs the tone subset to be used in a strip-symbol period using the method of the aspect and using data/information 2720 including downlink strip-symbol time info 2740 and sector ID 2752. The downlink tone subset allocation sequences will be different for each sector type in a cell and different for adjacent cells. The WTs 2800 receive the signals in the strip-symbol periods in accordance with the downlink tone subset allocation sequences; the base station 2700 uses the same downlink tone subset allocation sequences in order to generate the transmitted signals. Other downlink tone allocation hopping routine 2732 constructs downlink tone hopping sequences, using information including downlink tone information 2742, and downlink channel information 2756, for the symbol periods other than the strip-symbol periods. The downlink data tone hopping sequences are synchronized across the sectors of a cell. Beacon routine 2734 controls the transmission of a beacon signal, e.g., a signal of relatively high power signal concentrated on one or a few tones, which may be used for synchronization purposes, e.g., to synchronize the frame timing structure of the downlink signal and therefore the tone subset allocation sequence with respect to an ultra-slot boundary. FIG. 28 illustrates an example wireless terminal (e.g., end node, mobile device, . . . ) 2800 which can be used as any one of the wireless terminals (e.g., end nodes, mobile devices, . . . ), e.g., EN(1) 2636, of the system 2600 shown in FIG. 26. Wireless terminal 2800 implements the tone subset allocation sequences. Wireless terminal 2800 includes a receiver 2802 including a decoder 2812, a transmitter 2804 including an encoder 2814, a processor 2806, and memory 2808 which are coupled together by a bus 2810 over which the various elements 2802, 2804, 2806, 2808 can interchange data and information. An antenna 2803 used for receiving signals from a base station 2700 (and/or a disparate wireless terminal) is coupled to receiver 2802. An antenna 2805 used for transmitting signals, e.g., to base station 2700 (and/or a disparate wireless terminal) is coupled to transmitter 2804. The processor 2806 (e.g., a CPU) controls operation of wireless terminal 2800 and implements methods by executing routines 2820 and using data/information 2822 in memory 2808. Data/information 2822 includes user data 2834, user information 2836, and tone subset allocation sequence information 2850. User data 2834 may include data, intended for a peer node, which will be routed to encoder 2814 for encoding prior to transmission by transmitter 2804 to base station 2700, and data received from the base station 2700 which has been processed by the decoder 2812 in receiver 2802. User information 2836 includes uplink channel information 2838, downlink channel information 2840, terminal ID information 2842, base station ID information 2844, sector ID information 2846, and mode information 2848. Uplink channel information 2838 includes information identifying uplink channels segments that have been assigned by base station 2700 for wireless terminal 2800 to use when transmitting to the base station 2700. Uplink channels may include uplink traffic channels, dedicated uplink control channels, e.g., request channels, power control channels and timing control channels. Each uplink channel includes one or more logic tones, each logical tone following an uplink tone hopping sequence. The uplink hopping sequences are different between each sector type of a cell and between adjacent cells. Downlink channel information 2840 includes information identifying downlink channel segments that have been assigned by base station 2700 to WT 2800 for use when BS 2700 is transmitting data/information to WT 2800. Downlink channels may include downlink traffic channels and assignment channels, each downlink channel including one or more logical tone, each logical tone following a downlink hopping sequence, which is synchronized between each sector of the cell. User info 2836 also includes terminal ID information 2842, which is a base station 2700 assigned identification, base station ID information 2844 which identifies the specific base station 2700 that WT has established communications with, and sector ID info 2846 which identifies the specific sector of the cell where WT 2700 is presently located. Base station ID 2844 provides a cell slope value and sector ID info 2846 provides a sector index type; the cell slope value and sector index type may be used to derive tone hopping sequences. Mode information 2848 also included in user info 2836 identifies whether the WT 2800 is in sleep mode, hold mode, or on mode. Tone subset allocation sequence information 2850 includes downlink strip-symbol time information 2852 and downlink tone information 2854. Downlink strip-symbol time information 2852 include the frame synchronization structure information, such as the superslot, beaconslot, and ultraslot structure information and information specifying whether a given symbol period is a strip-symbol period, and if so, the index of the strip-symbol period and whether the strip-symbol is a resetting point to truncate the tone subset allocation sequence used by the base station. Downlink tone info 2854 includes information including a carrier frequency assigned to the base station 2700, the number and frequency of tones, and the set of tone subsets to be allocated to the strip-symbol periods, and other cell and sector specific values such as slope, slope index and sector type. Routines 2820 include communications routines 2824 and wireless terminal control routines 2826. Communications routines 2824 control the various communications protocols used by WT 2800. For example, communications routines 2824 may enable communicating via a wide area network (e.g., with base station 2700) and/or a local area peer-to-peer network (e.g., directly with disparate wireless terminal(s)). By way of further example, communications routines 2824 may enable receiving a broadcast signal (e.g., from base station 2700). Wireless terminal control routines 2826 control basic wireless terminal 2800 functionality including the control of the receiver 2802 and transmitter 2804. With reference to FIG. 29, illustrated is a system 2900 that enables communicating with allocated power levels. For example, system 2900 can reside at least partially within a base station. It is to be appreciated that system 2900 is represented as including functional blocks, which may be functional blocks that represent functions implemented by a processor, software, or combination thereof (e.g., firmware). System 2900 includes a logical grouping 2902 of electrical components that can act in conjunction. For instance, logical grouping 2902 can include an electrical component for transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern 2904. For instance, the first channel can include a first frequency bandwidth. Further, logical grouping 2902 can comprise an electrical component for transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern 2906. The second power level, for example, can be at least 0.5 dB different from the first power level. Additionally, system 2900 can include a memory 2908 that retains instructions for executing functions associated with electrical components 2904 and 2906. While shown as being external to memory 2908, it is to be understood that one or more of electrical components 2904 and 2906 can exist within memory 2908. With reference to FIG. 30, illustrated is a system 3000 that enables communicating with allocated power levels in a multiple carrier wireless communication network. For example, system 3000 can reside at least partially within a base station. It is to be appreciated that system 3000 is represented as including functional blocks, which may be functional blocks that represent functions implemented by a processor, software, or combination thereof (e.g., firmware). System 3000 includes a logical grouping 3002 of electrical components that can act in conjunction. For instance, logical grouping 3002 can include an electrical component for transmitting on a first channel at a first power level from a first sector during a first time period based on a first predetermined pattern 3004. For instance, the first channel can include a first frequency bandwidth. Further, logical grouping 3002 can comprise an electrical component for transmitting on the first channel at a second power level from the first sector during a second time period based on the first predetermined pattern 3006. Moreover, logical grouping 3002 can include an electrical component for transmitting on a second channel at a third power level from the first sector during the first time period based on a second predetermined pattern 3008. The second channel, for example, can include a second frequency bandwidth that does not overlap with the first frequency bandwidth in frequency. Logical grouping 3002 can also include an electrical component for transmitting on the second channel at a fourth power level from the first sector during the second time period based on the second predetermined pattern 3010. Additionally, system 3000 can include a memory 3012 that retains instructions for executing functions associated with electrical components 3004, 3006, 3008, and 3010. While shown as being external to memory 3012, it is to be understood that one or more of electrical components 3004, 3006, 3008, and 3010 can exist within memory 3012. When the embodiments are implemented in software, firmware, middleware or microcode, program code or code segments, they may be stored in a machine-readable medium, such as a storage component. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted using any suitable means including memory sharing, message passing, token passing, network transmission, etc. For a software implementation, the techniques described herein may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The software codes may be stored in memory units and executed by processors. The memory unit may be implemented within the processor or external to the processor, in which case it can be communicatively coupled to the processor via various means as is known in the art. What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.
|
H
|
H04
|
H04B
|
70
|
05
|
|||
11838048
|
US20080037816A1-20080214
|
FIT ADJUSTER FOR A NECKBAND TYPE HEADSET
|
ACCEPTED
|
20080130
|
20080214
|
[]
|
H04R2500
|
["H04R2500"]
|
8116477
|
20070813
|
20120214
|
381
|
087000
|
64498.0
|
WARREN
|
DAVID
|
[{"inventor_name_last": "LEE", "inventor_name_first": "Seung-Jae", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "YOON", "inventor_name_first": "Ki-Yeol", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "KIM", "inventor_name_first": "Ki-Taek", "inventor_city": "Yongin-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "KIM", "inventor_name_first": "Young-Ki", "inventor_city": "Yongin-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "JIN", "inventor_name_first": "Jae-Chul", "inventor_city": "Suwon-si", "inventor_state": "", "inventor_country": "KR"}]
|
Disclosed is a fit adjuster for a neckband type headset, which includes a headset band and a pair of earpieces connected to both ends of the headset band and placed on the ears of a user. The fit adjuster includes at least one opening formed at a stress concentration portion of the headset band; and an adjustment pin inserted into the opening to be movable in a longitudinal direction of the opening.
|
1. In a neckband type headset including a headset band and a pair of earpieces connected to both ends of the headset band and placed on the ears of a user, a fit adjuster comprising: at least one opening formed at a stress concentration portion of the headset band; and an adjustment pin inserted into the opening to be movable in a longitudinal direction of the opening. 2. The fit adjuster according to claim 1, wherein opening includes a first opening formed in a tunnel shape within the headset band; and a second opening formed on the outer surface of the headset band so as to spatially communicate with the first opening. 3. The fit adjuster according to claim 1, wherein the adjustment pin is made from a metal. 4. The fit adjuster according to claim 1, wherein the adjustment pin includes a rigid member longitudinally movable within the first opening; and an adjuster knob fixed at one end of the rigid member and protruding outward from the headset band. 5. The fit adjuster according to claim 4, wherein the rigid member is a metal plate. 6. The fit adjuster according claim 4, wherein the rigid member has a protector formed in a cylindrical shape at the other end thereof. 7. The fit adjuster according to claim 2, wherein the second opening includes at least one movement control means provided in a longitudinal direction thereof for control of a step-by-step movement of the adjustment pin. 8. The fit adjuster according to claim 7, wherein the movement control means is formed in a groove-like shape. 9. The fit adjuster according to claim 7, wherein the earpieces are wireless communication enabled.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates generally to a neckband type headset wearable on a particular part of the body, i.e. behind the user's head and neck, and in particular, to a fit adjuster for a neckband type headset using a short distance wireless communication module. 2. Description of the Related Art Generally, mobile communication terminals refer to handheld devices, which are capable of providing a user and another party with wireless communication services, including voice communication, message transmission, file transmission, video calling and a camera function. Mobile communication terminals can also allow for personal secretary services, such as telephone number management and scheduling. Mobile communication terminals are becoming smaller, slimmer and sleeker in order to improve portability and are also becoming multimedia devices which can offer multimedia services, for example, entertainment content services like music, videos and games. Mobile communication terminals have gone beyond merely being telephones and are becoming more multifunctional and complex to integrate various additional functions, including video calling, mobile gaming, Internet access and camera functions. Recently, short distance wireless communication interfaces, such as Bluetooth®, have been applied to mobile terminals. In addition, headsets that can be worn over the head are generally used with mobile terminals. Particularly, neckband type headsets with improved portability and wearing comfort have attained popularity. FIGS. 1 and 2 illustrate a conventional wired neckband type headset 10 . As illustrated, the conventional neckband type headset 10 has a fit adjustment means for minimizing wearing discomfort according to different head sizes of individual users. The conventional neckband type headset 10 includes an adjustable band 120 and a pair of earpieces attached to both ends of the adjustable band 120 . The pair of earpieces are right and left speakers 100 and 110 . The adjustable band 120 is held behind the user's head and neck. The right and left speakers 100 and 110 are lined with sponge earpads 111 and 101 providing a soft attachment to the ears. The adjustable band 120 has a property of being retained in its original position. The adjustable band 120 is generally made from plastic. It consists of a central part 122 and two extending parts 121 and 123 , which can be retracted into or withdrawn from the central part 120 to adjust the headset 10 for a comfortable fit. In other words, the conventional neckband type headset 10 has a structure that allows the user to adjust the length of the band 120 according to the size of the user's head to have a comfortable fit. However, the fit adjustment means adopted in the conventional neckband type headset 10 cannot be applied to headsets equipped with a Bluetooth® module for short-distance wireless communication. A wireless headset with a Bluetooth® module mounts a wire within a head band to electrically connect the right and left speakers, which makes it difficult to adjust the length of the head band. Unlike the head band of a wired neckband type headset, the head band of a wireless neckband type headset is not length-adjustable due to the wire mounted therein. Therefore, a new means for adjusting the fit of a wireless neckband type headset is in high demand.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a fit adjuster for a neckband type headset, which can provide long-wearing comfort. Another object of the present invention is to provide a fit adjuster for a neckband type headset, which can make step-by-step fit adjustment. Still another object of the present invention is to provide a fit adjuster for a neckband type headset, which allows a user to easily adjust the fit while wearing the headset. Still another object of the present invention is to provide a fit adjuster for a neckband type headset, which can improve strength of a headset band. In order to accomplish the above objects of the present invention, there is provided a neckband type headset including a headset band and a pair of earpieces connected to both ends of the headset band and placed on the ears of a user. The neckband type headset further includes a fit adjuster including at least one opening formed at a stress concentration portion of the headset band; and an adjustment pin inserted into the opening to be movable in a longitudinal direction of the opening.
|
PRIORITY This application claims priority under 35 U.S.C §119 to an application entitled “Fit Adjuster For Neckband Type Headset” filed in the Korean Intellectual Property Office on Aug. 11, 2006 and assigned Serial No. 2006-76408, the contents of which are hereby incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a neckband type headset wearable on a particular part of the body, i.e. behind the user's head and neck, and in particular, to a fit adjuster for a neckband type headset using a short distance wireless communication module. 2. Description of the Related Art Generally, mobile communication terminals refer to handheld devices, which are capable of providing a user and another party with wireless communication services, including voice communication, message transmission, file transmission, video calling and a camera function. Mobile communication terminals can also allow for personal secretary services, such as telephone number management and scheduling. Mobile communication terminals are becoming smaller, slimmer and sleeker in order to improve portability and are also becoming multimedia devices which can offer multimedia services, for example, entertainment content services like music, videos and games. Mobile communication terminals have gone beyond merely being telephones and are becoming more multifunctional and complex to integrate various additional functions, including video calling, mobile gaming, Internet access and camera functions. Recently, short distance wireless communication interfaces, such as Bluetooth®, have been applied to mobile terminals. In addition, headsets that can be worn over the head are generally used with mobile terminals. Particularly, neckband type headsets with improved portability and wearing comfort have attained popularity. FIGS. 1 and 2 illustrate a conventional wired neckband type headset 10. As illustrated, the conventional neckband type headset 10 has a fit adjustment means for minimizing wearing discomfort according to different head sizes of individual users. The conventional neckband type headset 10 includes an adjustable band 120 and a pair of earpieces attached to both ends of the adjustable band 120. The pair of earpieces are right and left speakers 100 and 110. The adjustable band 120 is held behind the user's head and neck. The right and left speakers 100 and 110 are lined with sponge earpads 111 and 101 providing a soft attachment to the ears. The adjustable band 120 has a property of being retained in its original position. The adjustable band 120 is generally made from plastic. It consists of a central part 122 and two extending parts 121 and 123, which can be retracted into or withdrawn from the central part 120 to adjust the headset 10 for a comfortable fit. In other words, the conventional neckband type headset 10 has a structure that allows the user to adjust the length of the band 120 according to the size of the user's head to have a comfortable fit. However, the fit adjustment means adopted in the conventional neckband type headset 10 cannot be applied to headsets equipped with a Bluetooth® module for short-distance wireless communication. A wireless headset with a Bluetooth® module mounts a wire within a head band to electrically connect the right and left speakers, which makes it difficult to adjust the length of the head band. Unlike the head band of a wired neckband type headset, the head band of a wireless neckband type headset is not length-adjustable due to the wire mounted therein. Therefore, a new means for adjusting the fit of a wireless neckband type headset is in high demand. SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a fit adjuster for a neckband type headset, which can provide long-wearing comfort. Another object of the present invention is to provide a fit adjuster for a neckband type headset, which can make step-by-step fit adjustment. Still another object of the present invention is to provide a fit adjuster for a neckband type headset, which allows a user to easily adjust the fit while wearing the headset. Still another object of the present invention is to provide a fit adjuster for a neckband type headset, which can improve strength of a headset band. In order to accomplish the above objects of the present invention, there is provided a neckband type headset including a headset band and a pair of earpieces connected to both ends of the headset band and placed on the ears of a user. The neckband type headset further includes a fit adjuster including at least one opening formed at a stress concentration portion of the headset band; and an adjustment pin inserted into the opening to be movable in a longitudinal direction of the opening. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a perspective view of a conventional neckband type headset; FIG. 2 is a front view of a conventional neckband type headset; FIG. 3 is a perspective view of a neckband type headset having a fit adjuster according to the present invention; FIG. 4 is a perspective view of a fit adjuster according to the present invention; FIG. 5 is a side view of the fit adjuster shown in FIG. 4; FIG. 6 is a partly enlarged front view of a neckband type headset with a fit adjuster incorporated according to the present invention; and FIG. 7 is a cross-sectional view taken along the line X-X of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description of the invention, detailed descriptions of functions and constructions incorporated herein, which are known to those skilled in the art are omitted for clarity and conciseness. As illustrated in FIGS. 3 through 5, a neckband type headset 20 according to the present invention includes a fit adjuster at a stress concentration portion of a headset band 220 which is placed behind a user's head. More specifically, the fit adjuster is mounted in the stress concentration portion of the headset band 220, which connects a pair of earpieces 200 and 210. The fit adjuster is preferably applied to a neckband type headset using a short distance wireless communication module, for example, a Bluetooth® module. The headset 20 according to the present invention has openings 221 and 223 formed in the headset band 220 and an adjustment pin 231 which can be inserted into the openings 221 and 223. As illustrated in FIGS. 6 and 7, the openings 221 and 223 are formed at the stress concentration portion 222 of the headset band 220, which is symmetrical with respect to the center thereof. Preferably, the stress concentration portion 222 should be provided at the center of the headset band 220. The openings 221 and 223 are formed to movably mount the adjustment pin 231 therein. More specifically, the first opening 221 is longitudinally formed in a tunnel shape within the headset band 220. The second opening 223 is formed on the outer surface of the headset band 220 so as to spatially communicate with the first opening 221. The first opening 221 is hidden inside the headset band 220, whereas the second opening 223 is exposed on the headset band 220. As illustrated in FIGS. 4, 5 and 7, the adjustment pin 231 is a movable element, which is mounted in the first and second openings 221 and 223. The adjustment pin 231 includes a rigid member 232 longitudinally movable within the first opening 221 and an adjuster knob 234 fixed at one end of the rigid member 232 and protruding outward from the headset band 220. The rigid member 232 is movable within the first opening 221. A neck portion connecting the rigid member 232 and the adjuster knob 234 is movable within the second opening 223. Also, the adjuster knob 234 is movable above the second opening 223. The rigid member 232 is made from a metal. It is formed in a metal plate shape to effectively absorb the stress transferred to the stress concentration region while the user is wearing the headset 20. The rigid member 232 has a protector 236 formed in a cylindrical shape at the other end thereof. The protector 236 reduces friction generated between the rigid member 232 and the interior of the headset band 220 during movement of the rigid member 231 within the first opening 221. With the reduction of friction, the protector 236 can protect the wall of the first opening 221 in the headset band 220 from easily wearing away. As illustrated in FIGS. 6 and 7, the fit adjuster of the present invention further includes at least one movement control means 225 provided in a longitudinal direction of the second opening 223. The movement control means 225 is formed in a groove-like shape to allow the step-by-step movement of the adjustment pin 231. It is preferable to provide a pair of movement control means 225 facing each other. The user can forcibly move the adjustment pin 231 along the first opening. Referring to FIG. 7, when the adjustment pin 231 is moved in a left direction, the user will feel a higher pressure put on the ears. When the adjustment pin 231 is moved in a right direction, the pressure will be reduced. The fit adjuster according to the present invention is mounted slightly above the longitudinal center of the cross-section of the headset band 220 because of a wire W (FIG. 7) mounted in the band 220 to connect the right and left speakers. As explained above, the fit adjuster according to the present invention is applicable to a neckband type headset using a short distance wireless communication module. The fit adjuster fits the headset tightly on the back of the neck, thereby preventing the headset from slipping off even during active sports or extended wearing time. The fit adjuster enables users of different head sizes to adjust the length of the headset band and find the most comfortable fit. Since the fit adjuster ensures tight fit on the ears of the user, it can minimize the leakage of sound outputted from the speakers. In addition, the fit adjuster mounted at the stress concentration portion of the headset band can improve the strength of the headset and thereby extend the headset life. Although preferred embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims, including the full scope of equivalents thereof.
|
H
|
H04
|
H04R
|
25
|
00
|
|||
11836519
|
US20080025676A1-20080131
|
Laser Adjustment in Integrated Optoelectronic Modules/Fiber Optic Cables
|
ACCEPTED
|
20080116
|
20080131
|
[]
|
G02B636
|
["G02B636"]
|
7581891
|
20070809
|
20090901
|
385
|
088000
|
94395.0
|
PEACE
|
RHONDA
|
[{"inventor_name_last": "Wang", "inventor_name_first": "Xiaozhong", "inventor_city": "Sunnyvale", "inventor_state": "CA", "inventor_country": "US"}]
|
An integrated optoelectronic module and optical fiber for coupling a pair of information system devices having an electrical input/output interface using optical signal communication including an optical fiber; a housing on at least one end of the optical fiber including an electrical connector for coupling with one of said information system devices; an electro-optic subassembly disposed in the housing for coupling to the information system device integrally coupled and attached to the optical fiber for transmitting an optical signal over the fiber; a circuit disposed in the housing for detecting the power of the received optical signal; and a communications interface for communicating the received power level to allow setting of the remove optics transmitter.
|
1. An integrated optical fiber and optoelectronic module for optically coupling a pair of information system devices having an electrical input/output interface comprising: an optical fiber; a first terminal housing located at one end of the optical fiber including (i) an electrical connector for coupling with one of said information system devices and for transmitting information-containing electrical signals over said connector; (ii) an electro-optic subassembly disposed in said housing for converting the electrical signal to and from a modulated optical signal corresponding to the electrical signals at a predetermined wavelength, said subassembly being integrally coupled and attached to said optical fiber for transmitting or receiving an optical signal to or from a remote device; (iii) a power detection circuit disposed in said housing for detecting the power level of the optical signal received over the optical fiber from a remote transmitter; and (iv) a communications interface disposed in said housing for communicating the magnitude of said received power level to allow setting of operational parameters in the remote device. 2. The integrated module of claim 1, wherein said power detection circuit includes a photodiode and a signal processing circuit for producing a power adjustment signal. 3. The integrated module of claim 2, wherein the output of said signal processing circuit is coupled to said electro-optical assembly for optically transmitting the power adjustment signal to the remote device. 4. The integrated module of claim 3, wherein said electro-optical subassembly includes a power adjustment circuit responsive to a power adjustment signal for adjusting the power of the output optical signal. 5. The integrated module of claim 1, wherein said electrical connector is an Infiniband connector. 6. The integrated module of claim 2, wherein the power adjustment signal is transmitting during a control mode of operation of the module. 7. The integrated module of claim 4, wherein the electro-optical assembly includes a VCSEL, and said power adjustment circuit sets the output power of the VCSEL. 8. The integrated module of claim 7, wherein the power adjustment signal sets the operating temperature of the VCSEL. 9. The integrated module of claim 1, wherein the other end of the fiber is coupled to a second terminal housing located at the other end of the optical fiber including (i) an electrical connector for coupling with one of said information system devices and for transmitting information containing electrical signals over said connector; (ii) an electro-optic subassembly disposed in said second housing for converting the electrical signal to and from a modulated optical signal corresponding to the electrical signals at a predetermined wavelength, said subassembly being integrally coupled and attached to said optical fiber for transmitting or receiving an optical signal; (iii) a power detection circuit disposed in said second housing for detecting the power level of the optical signal received over the fiber from the first terminal; and (iv) a communications interface disposed in said second housing for communicating the magnitude of said received power level to allow setting of operational parameters in the electro-optical subassembly in the first terminal housing. 10. The integrated module of claim 1, wherein said optical fiber is approximately 10 meters in length. 11. A communications cable for providing a short range, high speed optical data communications link between information system units comprising: a group of 2N optical fibers, where N is a positive integer; a first terminal housing integral with and disposed at a first end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to a first set of N of said optical fibers, and a photodiode array abutting and coupled to a second set of N of said optical fibers; (ii) a signal detector coupled to said photodiode array for determining the power of an optical signal on at least one of said optical fibers; (iii) a power adjustment circuit coupled to said VCSEL array for adjusting the power output of at least one of said VCSELs in response to the level of received power of said one VCSEL in said second terminal housing; and (iv) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a first external information system unit for transferring information signals between the unit and the communications link; and a second terminal housing integral with and disposed at a second end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to the second set of N of said optical fibers, and a photodiode array abutting and coupled to the first set of N of said optical fibers; (ii) a signal detector coupled to said photodiode array for determining the power of an optical signal on at least one of said optical fibers; (iii) a power adjustment circuit coupled to said VCSEL array for adjusting the power output of at least one of said VCSELs in response to the level of received power of said one VCSEL in said first terminal housing; and (iv) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a second external information system unit for transferring information signals between the unit and the communications link. 12. The integrated module of claim 11, wherein said terminal housings include a module controller. 13. The integrated module of claim 10, wherein the power adjustment signal is transmitted during a control mode of operation of the module controller. 14. The integrated module of claim 11, wherein said power adjustment circuit sets the output power of one of the VCSELs in the remote transmitter. 15. The integrated module of claim 11, wherein the power adjustment signal sets the operating temperature of one of the VCSELs in the remote transmitter. 16. A communications cable for providing a short range, high speed optical data communications link between information system units comprising: a group of 2N optical fibers, where N is a positive integer; a first terminal housing integral with and disposed at a first end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to a first set of N of said optical fibers, and a photodiode array abutting and coupled to a second set of N of said optical fibers; and (ii) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a first external information system unit for transferring information signals between the unit and the communications link; and a second terminal housing integral with and disposed at a second end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to the second set of N of said optical fibers, and a photodiode array abutting and coupled to the first set of N of said optical fibers; and (ii) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a second external information system unit for transferring information signals between the unit and the communications link.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to optical communications systems, and parallel optic transceivers used in high throughput fiber optic communications links in local and wide area networks and storage networks, and in particular to fiber optic cables with integral transceivers mounted at each end for coupling to an electrical connector on an information system unit. 2. Description of the Related Art Communications networks have experienced dramatic growth in data transmission traffic in recent years due to worldwide Internet access, e-mail, and e-commerce. As Internet usage grows to include transmission of larger data files, including content such as full motion video on-demand (including HDTV), multi-channel high quality audio, online video conferencing, image transfer, and other broadband applications, the delivery of such data will place a greater demand on available bandwidth. The bulk of this traffic is already routed through the optical networking infrastructure used by local and long distance carriers, as well as Internet service providers. Since optical fiber offers substantially greater bandwidth capacity, is less error prone, and is easier to administer than conventional copper wire technologies, it is not surprising to see increased deployment of optical fiber in data centers, storage area networks, and enterprise computer networks for short range network unit to network unit interconnection. Such increased deployment has created a demand for electrical and optical transceiver modules that enable data system units such as computers, storage units, routers, and similar devices to be optionally coupled by either an electrical cable or an optical fiber to provide a high speed, short reach (less than 100 meters) data link within the data center. A variety of optical transceiver modules are known in the art to provide such interconnection that include an optical transmit portion that converts an electrical signal into a modulated light beam that is coupled to a first optical fiber, and a receive portion that receives a optical signal from a second optical fiber and converts it into an electrical signal, and similar implementations employ one fiber for both optical signals, traveling in opposite directions. The electrical signals are transferred in both directions over an electrical connectors that interface with the network unit using a standard electrical data link protocol, such as Infiniband. The optical transmitter section of such transceiver modules includes one or more semiconductor lasers and an optical assembly to focus or direct the light from the lasers into an optical fiber or fibers, which in turn, is connected to a receptacle or connector on the transceiver to allow an external optical fiber to be connected thereto using a standard connector, such as SC, FC, LC, or ribbon fiber type MPO. The optical receive section includes an optical assembly to focus or direct the light from the optical fiber or fibers onto a photodetector or array, which in turn, is connected to an IC circuit on a circuit board. Optical transceiver modules are therefore packaged in a number of standard form factors which are “hot pluggable” into a rack mounted line card network unit or the chassis of the data system unit. Standard form factors set forth in Multiple Source Agreements (MSAs) provide standardized dimensions and input/output interfaces that allow devices from different manufacturers to be used interchangeably. Some of the most popular MSAs include XENPAK (see www.xenpak.org), X2 (see www.X2 msa.org), SFF (“small form factor”), SFP (“small form factor pluggable”), XFP (“10 Gigabit Small Form Factor Pluggable”, see www.XFPMSA.org), and the QSFP (“Quad Small Form-factor Pluggable,” see www.QSFPMSA.org). In addition to such pluggable modules, customers and users of such systems are increasingly interested in fiber optic cables which incorporate integral transceivers fixedly mounted on the ends of such cables such as described in U.S. patent application Ser. No. 10/965,984. In order to increase the number of interconnections or port density associated with the network unit, such as, for example in rack mounted line cards, switch boxes, cabling patch panels, wiring closets, and computer I/O interfaces, such transceivers should be able to couple to multiple parallel optical fibers, or ribbons, and utilize parallel electro-optical converters in the transceivers. A typical parallel optical transceiver consists of a vertical cavity surface emitter laser (VCSEL) array, and a PIN diode array. A parallel optical ribbon can be inserted into the optical transceiver, coupling to the VCSEL array or the PIN diode array, and individual lane transmitter and receiver properties can be measured. In these measurements the light source, a VCSEL array is adjusted or programmed over temperature to maintain good operating characteristics. The purpose of such receiver side measurements is that the driving conditions (e.g. bias voltage and current) of the VCSELs (or any other lasers) need to be adjusted and set at the factory since their threshold and efficiency varies from device to device and also changes as a function of temperature. In an integrated module/optical cable, the parallel ribbon fiber may be permanently attached to electrical-optical converters at both ends. Since the optical interface is not accessible on either end, the VCSEL performance can not be measured or characterized directly. An alternative method must be found to properly characterize the performance of VCSEL over temperature to ensure the performance of the communications link.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Briefly, and in general terms, the present invention provides, an integrated optical fiber and optoelectronic module for optically coupling a pair of information system devices having an electrical input/output interface using optical signal communication including an optical fiber; a first term housing including (i) an electrical connector for coupling with one of the information system devices and for transmitting or receiving information-containing electrical signals over the connector; (ii) an electro-optic subassembly disposed in the housing for coupling to the information system device for converting the electrical signal to a modulated optical signal corresponding to the electrical signals at a predetermined wavelength, the subassembly being integrally coupled and attached to the optical fiber for transmitting or receiving an optical signal; a power detector circuit disposed in the housing for detecting the power level of the optical signal received over the optical fiber; and a communications interface disposed in the housing for communicating the power level to allow setting of the operational parameters in the remote device. In another aspect, the invention provides an electro-optical connector module integral with an optical fiber cable having a plurality of parallel optical transmit lanes and a plurality of parallel optical receiver lanes, the module comprising optical receiver lane signal detection circuitry to detect the signal power on one or more of the receive lanes, and optical transmit lane control circuitry to transmit a control mode optical signal indicating the received signal power on the corresponding receive lane. In another aspect, the invention provides a communications cable for providing a short range, high speed optical data communications link between information system units including a group of 2N optical fibers, where N is a positive integer; a first terminal housing integral with and disposed at a first end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to a first set of N of said optical fibers, and a photodiode array abutting and coupled to a second set of N of said optical fibers; (ii) signal detection means coupled to said photodiode array for determining the power of a optical signal on at least one of said optical fibers; (iii) power adjustment means coupled to said VCSEL array for adjusting the power output of at least one of said VCSELs in response to the level of received power of said one VCSEL in said second terminal housing; and (iv) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a first external information system unit for transferring information signals between the unit and the communications link; and a second terminal housing integral with and disposed at a second end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to the second set of N of said optical fibers, and a photodiode array abutting and coupled to the first set of N of said optical fibers; (ii) signal detection means coupled to said photodiode array for determining the power of a optical signal on at least one of said optical fibers; (iii) power adjustment means coupled to said VCSEL array for adjusting the power output of at least one of said VCSELs in response to the level of received power of said one VCSEL in said first terminal housing; and (iv) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a second external information system unit for transferring information signals between the unit and the communications link. In another aspect, the invention provides a communications cable for providing a short range, high speed optical data communications link between information system units including: a group of 2N optical fibers, where N is a positive integer; a first terminal housing integral with and disposed at a first end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to a first set of N of said optical fibers, and a photodiode array abutting and coupled to a second set of N of said optical fibers; and (ii) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a first external information system unit for transferring information signals between the unit and the communications link; and a second terminal housing integral with and disposed at a second end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to the second set of N of said optical fibers, and a photodiode array abutting and coupled to the first set of N of said optical fibers; and (ii) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a second external information system unit for transferring information signals between the unit and the communications link. In a preferred embodiment, the module also includes optical receiver lane signal detection circuitry for detecting the transmitted control mode optical signal, and to controlling the laser bias of the corresponding laser to the receive lane on which the optical signal was received.
|
REFERENCE TO RELATED APPLICATIONS This application is a continuation in part of U.S. patent application Ser. No. 10/965,984 filed Oct. 15, 2004, and U.S. patent application Ser. No. 11/732,996 filed Apr. 5, 2007, both assigned to the common assignee. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to optical communications systems, and parallel optic transceivers used in high throughput fiber optic communications links in local and wide area networks and storage networks, and in particular to fiber optic cables with integral transceivers mounted at each end for coupling to an electrical connector on an information system unit. 2. Description of the Related Art Communications networks have experienced dramatic growth in data transmission traffic in recent years due to worldwide Internet access, e-mail, and e-commerce. As Internet usage grows to include transmission of larger data files, including content such as full motion video on-demand (including HDTV), multi-channel high quality audio, online video conferencing, image transfer, and other broadband applications, the delivery of such data will place a greater demand on available bandwidth. The bulk of this traffic is already routed through the optical networking infrastructure used by local and long distance carriers, as well as Internet service providers. Since optical fiber offers substantially greater bandwidth capacity, is less error prone, and is easier to administer than conventional copper wire technologies, it is not surprising to see increased deployment of optical fiber in data centers, storage area networks, and enterprise computer networks for short range network unit to network unit interconnection. Such increased deployment has created a demand for electrical and optical transceiver modules that enable data system units such as computers, storage units, routers, and similar devices to be optionally coupled by either an electrical cable or an optical fiber to provide a high speed, short reach (less than 100 meters) data link within the data center. A variety of optical transceiver modules are known in the art to provide such interconnection that include an optical transmit portion that converts an electrical signal into a modulated light beam that is coupled to a first optical fiber, and a receive portion that receives a optical signal from a second optical fiber and converts it into an electrical signal, and similar implementations employ one fiber for both optical signals, traveling in opposite directions. The electrical signals are transferred in both directions over an electrical connectors that interface with the network unit using a standard electrical data link protocol, such as Infiniband. The optical transmitter section of such transceiver modules includes one or more semiconductor lasers and an optical assembly to focus or direct the light from the lasers into an optical fiber or fibers, which in turn, is connected to a receptacle or connector on the transceiver to allow an external optical fiber to be connected thereto using a standard connector, such as SC, FC, LC, or ribbon fiber type MPO. The optical receive section includes an optical assembly to focus or direct the light from the optical fiber or fibers onto a photodetector or array, which in turn, is connected to an IC circuit on a circuit board. Optical transceiver modules are therefore packaged in a number of standard form factors which are “hot pluggable” into a rack mounted line card network unit or the chassis of the data system unit. Standard form factors set forth in Multiple Source Agreements (MSAs) provide standardized dimensions and input/output interfaces that allow devices from different manufacturers to be used interchangeably. Some of the most popular MSAs include XENPAK (see www.xenpak.org), X2 (see www.X2 msa.org), SFF (“small form factor”), SFP (“small form factor pluggable”), XFP (“10 Gigabit Small Form Factor Pluggable”, see www.XFPMSA.org), and the QSFP (“Quad Small Form-factor Pluggable,” see www.QSFPMSA.org). In addition to such pluggable modules, customers and users of such systems are increasingly interested in fiber optic cables which incorporate integral transceivers fixedly mounted on the ends of such cables such as described in U.S. patent application Ser. No. 10/965,984. In order to increase the number of interconnections or port density associated with the network unit, such as, for example in rack mounted line cards, switch boxes, cabling patch panels, wiring closets, and computer I/O interfaces, such transceivers should be able to couple to multiple parallel optical fibers, or ribbons, and utilize parallel electro-optical converters in the transceivers. A typical parallel optical transceiver consists of a vertical cavity surface emitter laser (VCSEL) array, and a PIN diode array. A parallel optical ribbon can be inserted into the optical transceiver, coupling to the VCSEL array or the PIN diode array, and individual lane transmitter and receiver properties can be measured. In these measurements the light source, a VCSEL array is adjusted or programmed over temperature to maintain good operating characteristics. The purpose of such receiver side measurements is that the driving conditions (e.g. bias voltage and current) of the VCSELs (or any other lasers) need to be adjusted and set at the factory since their threshold and efficiency varies from device to device and also changes as a function of temperature. In an integrated module/optical cable, the parallel ribbon fiber may be permanently attached to electrical-optical converters at both ends. Since the optical interface is not accessible on either end, the VCSEL performance can not be measured or characterized directly. An alternative method must be found to properly characterize the performance of VCSEL over temperature to ensure the performance of the communications link. SUMMARY OF THE INVENTION Briefly, and in general terms, the present invention provides, an integrated optical fiber and optoelectronic module for optically coupling a pair of information system devices having an electrical input/output interface using optical signal communication including an optical fiber; a first term housing including (i) an electrical connector for coupling with one of the information system devices and for transmitting or receiving information-containing electrical signals over the connector; (ii) an electro-optic subassembly disposed in the housing for coupling to the information system device for converting the electrical signal to a modulated optical signal corresponding to the electrical signals at a predetermined wavelength, the subassembly being integrally coupled and attached to the optical fiber for transmitting or receiving an optical signal; a power detector circuit disposed in the housing for detecting the power level of the optical signal received over the optical fiber; and a communications interface disposed in the housing for communicating the power level to allow setting of the operational parameters in the remote device. In another aspect, the invention provides an electro-optical connector module integral with an optical fiber cable having a plurality of parallel optical transmit lanes and a plurality of parallel optical receiver lanes, the module comprising optical receiver lane signal detection circuitry to detect the signal power on one or more of the receive lanes, and optical transmit lane control circuitry to transmit a control mode optical signal indicating the received signal power on the corresponding receive lane. In another aspect, the invention provides a communications cable for providing a short range, high speed optical data communications link between information system units including a group of 2N optical fibers, where N is a positive integer; a first terminal housing integral with and disposed at a first end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to a first set of N of said optical fibers, and a photodiode array abutting and coupled to a second set of N of said optical fibers; (ii) signal detection means coupled to said photodiode array for determining the power of a optical signal on at least one of said optical fibers; (iii) power adjustment means coupled to said VCSEL array for adjusting the power output of at least one of said VCSELs in response to the level of received power of said one VCSEL in said second terminal housing; and (iv) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a first external information system unit for transferring information signals between the unit and the communications link; and a second terminal housing integral with and disposed at a second end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to the second set of N of said optical fibers, and a photodiode array abutting and coupled to the first set of N of said optical fibers; (ii) signal detection means coupled to said photodiode array for determining the power of a optical signal on at least one of said optical fibers; (iii) power adjustment means coupled to said VCSEL array for adjusting the power output of at least one of said VCSELs in response to the level of received power of said one VCSEL in said first terminal housing; and (iv) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a second external information system unit for transferring information signals between the unit and the communications link. In another aspect, the invention provides a communications cable for providing a short range, high speed optical data communications link between information system units including: a group of 2N optical fibers, where N is a positive integer; a first terminal housing integral with and disposed at a first end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to a first set of N of said optical fibers, and a photodiode array abutting and coupled to a second set of N of said optical fibers; and (ii) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a first external information system unit for transferring information signals between the unit and the communications link; and a second terminal housing integral with and disposed at a second end of said 2N optical fibers, including (i) an multi-channel electro-optical converter including a VCSEL array abutting and coupled to the second set of N of said optical fibers, and a photodiode array abutting and coupled to the first set of N of said optical fibers; and (ii) an electrical connector extending from the housing and adapted to mate with a corresponding electrical connector on a second external information system unit for transferring information signals between the unit and the communications link. In a preferred embodiment, the module also includes optical receiver lane signal detection circuitry for detecting the transmitted control mode optical signal, and to controlling the laser bias of the corresponding laser to the receive lane on which the optical signal was received. BRIEF DESCRIPTION OF THE DRAWINGS These and other features and advantages of this invention will be better understood and more fully appreciated by reference to the following detailed description when considered in conjunction with the accompanying drawings, wherein: FIG. 1 is an exploded perspective view of a pluggable parallel optoelectronic module as known in the prior art coupled to a ribbon fibers; FIG. 2 is a perspective view of a pluggable module being inserted into a receptacle or cage in a host unit; FIG. 3 is a highly simplified perspective view of an integral transceiver/optical fiber cable at one end of a fiber according to the present invention; and FIG. 4 is a highly simplified block diagram of a transceiver module according to the present invention. Additional objects, advantages, and novel features of the present invention will become apparent to those skilled in the art from this disclosure, including the following detailed description as well as by practice of the invention. While the invention is described below with reference to preferred embodiments, it should be understood that the invention is not limited thereto. Those of ordinary skill in the art having access to the teachings herein will recognize additional applications, modifications and embodiments in other fields, which are within the scope of the invention as disclosed and claimed herein and with respect to which the invention could be of utility. DESCRIPTION OF THE PREFERRED EMBODIMENT Details of the present invention will now be described including exemplary aspects and embodiments thereof. Referring to the drawings and the following description, like reference numbers are used to identify like or functionally similar elements, and are intended to illustrate major features of exemplary embodiments in a highly simplified diagrammatic manner. Moreover, the drawings are not intended to depict every feature of the actual embodiment nor the relative dimensions of the depicted elements, and are not drawn to scale. The present invention relates generally to the adjustment of laser transmitter parameters, such as electrical bias and operating temperature in optical communications transceiver modules used in fiber optic communications systems. Referring now to FIG. 1, there is shown an exploded view of an exemplary pluggable optical transceiver module 100 as known in the prior art. In this particular example, the module 100 is compliant with the QSFP MSA. In this particular case the optical transceiver has four transmit channels and four receiving channels. Each transmit channel can transmit optical signal at 850 nm or its vicinity, at up to 10 Gbps data rate. Each receiving channel can receive the 850 nm signal and convert it into an electrical signal at the same data rate. The transceiver module 100 includes a two-piece housing including a base 102 and a cover 101. The housing 101 and 102 are constructed of die-case or milled metal, preferably die-cast zinc, although other materials also may be used, such as specialty plastics and the like. Preferably, the particular material used in the housing construction assists in reducing EMI. The front end of the housing 102 includes a port 115 for securing a MPO insert 114. The insert is configured to receive an MPO fiber optic connectors (not shown) which mate with optical lens 112 An EMI blocker 113 is inserted in between the lens and the MPO insert to block EMI from emitting into open space in the front. In the illustrated example, the housing holds one subassembly or circuit boards, including a rigid circuit board 103, a flexible board 105, a microprocessor 104 which is used to control the laser driver IC 109 and receiver IC 111. Both ICs sit on a thermally conductive substrate 106, and are connected to the flexible circuit board 105 through wirebond. A VCSEL array 108 and photodiode array 110 are also located on the substrate 106, and are wirebonded to 109 and 111 respectively. The optical lens array 112 is aligned to both the VCSEL array 108 and photodiode array 110 to provide best coupling from the VCSEL array to the fiber ribbon, and from fiber ribbon to the photodiode array. FIG. 2 is a perspective view of a prior art pluggable modules (202 and 203) inserted into a receptacle or cage in a host unit. An optical cable connector 205 is employed to connect module 202 to the host optical cable plant 206 by mating with the pluggable fiber port 204 within module 202. FIG. 3 is a perspective view of an integrated transceiver/optical fiber according to the present invention. The transceiver module 400 at one end of the cable includes a two-piece housing 300 including a base 301 and a cover 302. In addition, contact strips (not shown) may be provided to ground the module to an external chassis ground as well. The housing 300 is constructed of die-case or milled metal, preferably die-cast zinc, although other materials also may be used, such as specialty plastics and the like. Preferably, the particular material used in the housing construction assists in reducing EMI. A similar configuration is shown in U.S. Pat. No. 7,137,744 of the present assignee, which is hereby incorporated by reference. The front end of the housing 303 includes a faceplate 304 that secures the optical fiber ribbon 420 (as shown in FIG. 4). In the illustrated example, the housing 300 holds a simple printed circuit board 305 including a transmit driver IC 401, a receive controller 405, and a microprocessor or module controller. An electrical connector 421 is formed by electrical contacts on both sides of the module, to provide an electrical interface to the mating receptacle connector on the external computer or communications unit (not shown). The VCSEL transmit subassembly 402 includes a VCSEL array of N semiconductor lasers, which may be mounted in a single plastic enclosure 306, which interfaces to N fibers of a fiber ribbon ferrule 307. Adjacent to the VCSEL array 402 is a photodiode array 404 which interfaces to the ribbon ferrule 307, and thereby to N fibers of the 2N fiber ribbon cable 420. The enclosure 306 is electrical coupled to the printed circuit board 305 by means of the flex cable 307 and mechanical supports 308, 309 which sandwich the printed circuit board (PCB) 305 there between, and allow the cable 307 to make electrical contact with appropriate traces on board 305. Other electrical components 310, 311, 403 for driving the VCSEL transmitters 402, and amplifying and processing the signals from the photodiode array 404 are also shown mounted on the PCB 305, and will be described in greater detail in connection with FIG. 4. On the right hand side of the Figure is depicted the ribbon ferrule 307 which secures the ribbon cable 420 to the housing 400. The ribbon ferrule 307 allows the individual fibers in the cable 420 to be aligned with the N VCSELs and N photodiodes as disposed on the enclosure 306. Suitable alignment pins and mating receptacles are provided on the enclosure 306 and the ferrule 307 so that the optical coupling between the VCSEL/photodiode array and the fiber ribbon may be achieved in the most expeditious manner from a manufacturing perspective, the details of which go beyond the scope of the present invention. Suffice it to say that once aligned, the ferrule is glued or otherwise fixedly secured to the enclosure 306 so that the ribbon cable 420 is fixedly secured to the transceiver module 400. FIG. 4 is a block diagram illustrating an integrated optoelectronic module/fiber optic cable with an electro-optical module at each end according to an embodiment of the invention. Here, a first electro-optical module 400 at end A of the cable is provided, which is connected, via a parallel optical ribbon 420 comprising 2N fibers, where N is an integer, to a second electro-optical module 409, provided at end B of the cable. The first electro-optical module 400 comprises a VCSEL array 402, comprising N VCSELs arranged in parallel. Also provided is a photodiode array 404, comprising N photodiodes arranged in parallel. A module controller 406 is further provided, as well as a receiver controller 405, arranged to receive signals from the photodiode array. A transmitter driver 401, which controls the VCSEL array, is also included. The transmitter driver 401 is arranged to receive data from a coupled information system device, in the form of an electrical signal over electrical connector 421, and to control the VCSEL, which converts the electrical signal into an optical signal, which is transmitted via the parallel optical fiber 420. Similarly, the parallel optical signal received at the photodiode array 404 is converted into an electrical signal and passed to the receiver controller 405, and then output as an electrical data output signal over connector 421. The overall operation of the electro-optical module 400 to convert between the optical and electrical domains is controlled by the module controller 403, in a conventional manner. The electro-optical module 409 has a corresponding structure to the first electro-optical module 400. In this respect, the second electro-optical module 409 comprises a photodiode array 410, having N photodiodes arranged in parallel. The photodiode array 410 feeds a signal to the receiver controller at 411, which then outputs an electrical data out signal. Also provided is a VCSEL array 415, comprising N VCSEL lasers arranged in parallel. A transmitter driver circuit 414 is arranged to receive an electrical data input signal, and to drive VCSEL array 415 so to produce a parallel optical signal, which is then output over the N fibers 416. The overall operation of the electro-optical module 409 to convert between the electrical and optical domains is controlled by the module controller 413, in a conventional manner. It should be noted that the photodiode array 410 of the second electro-optical module 409 is coupled by N fibers 408 to the VCSEL array 402 of the first electro-optical module 400, while the VCSEL array 415 of the second electro-optical module 409 is coupled to the photodiode array 404 of the first electro-optical module 400. The coupling is performed by a parallel optical ribbon, in this case having 2N optical fibers, with N fibers 408 carrying the signal from 402 to 410, and N fibers 416 carrying the signals from 415 to 404. Thus, according to the embodiment, where an electro-optical module according to the embodiment detects the power level of a received signal on one of its receive lanes, it converts the data into an electrical control signal which is transmitted preferably in a predetermined format to the remote transmitting module. The control signal is applied to the module controller 406 to set power level of each VCSEL in the array 402 in response to the respective received power in the photodiode array 410 in module 409. A similar operation would be performed in module 400 to set the power level of VCSEL array 415. Such an adjustment in bias and operating current is done by conventional techniques known in the art, and allows both the modules 400 and 409 to be adjusted and tuned at the factory, so that the entire integral transceiver/fiber cable assembly 400, 420, 409 is ready for use when received by the customer or end user. Within the above described first embodiment there is a corresponding number of transmit and receive lanes at both transceivers, providing a one to one correspondence. However, while this is preferred to give the greatest open fiber signaling resolution, in other embodiments there can be a different number of transmit and receive lanes, provided that each transmit lane is “paired” with a receive lane, even if more than one transmit lane/receive lane is paired with the same receive lane/transmit lane. In summary, therefore, the embodiments of the invention allow the VCSELs driving parallel optical links to be adjusted and controlled substantially on a per lane basis, by pairing transmit and receive lanes. Further modifications, substitutions, additions and/or rearrangements to the above described embodiments and falling within the spirit and/or scope of the underlying inventive concept will be apparent to the person skilled in the art to provide further embodiments of the invention, any and all of which are intended to be encompassed by the appended claims. Various aspects of the techniques and apparatus of the present invention may be implemented in digital circuitry, or in computer hardware, firmware, software, or in combinations of them. Circuits of the invention may be implemented in computer products tangibly embodied in a machine-readable storage device for execution by a programmable processor, or on software located at a network node or web site which may be downloaded to the computer product automatically or on demand. The foregoing techniques may be performed by, for example, a single central processor, a multiprocessor, one or more digital signal processors, gate arrays of logic gates, or hardwired logic circuits for executing a sequence of signals or program of instructions to perform functions of the invention by operating on input data and generating output. The methods may advantageously be implemented in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one in/out device, and at least one output device. Each computer program may be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language may be compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, a processor will receive instructions and data from read-only memory and/or random access memory. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example, semiconductor devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing may be supplemented by or incorporated in, specially designed application-specific integrated circuits (ASICS). It will be understood that each of the elements described above, or two or more together, also may find a useful application in other types of constructions differing from the types described above. While the invention has been illustrated and described as embodied in an optical transmission system, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.
|
G
|
G02
|
G02B
|
6
|
36
|
|||
11878942
|
US20080076601A1-20080327
|
Golf ball
|
ACCEPTED
|
20080312
|
20080327
|
[]
|
A63B3706
|
["A63B3706"]
|
7637824
|
20070727
|
20091229
|
473
|
351000
|
76969.0
|
GORDEN
|
RAEANN
|
[{"inventor_name_last": "Shindo", "inventor_name_first": "Jun", "inventor_city": "Chichibu-shi", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Takehana", "inventor_name_first": "Eiji", "inventor_city": "Chichibu-shi", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Yamazaki", "inventor_name_first": "Kae", "inventor_city": "Chichibu-shi", "inventor_state": "", "inventor_country": "JP"}]
|
The present invention provides a golf ball having a core and a cover of one or more layer, wherein the core is made of a material obtained by molding under heat a rubber composition which includes (a) a base rubber containing polybutadiene having a stress relaxation time (T80) of 3.5 or less, (b) an unsaturated carboxylic acid and/or a metal salt thereof, and (c) an organic peroxide, and wherein at least one layer of the cover is made of a material obtained by molding a mixture containing as the essential ingredients (A) a metal ion neutralized olefin-unsaturated carboxylic acid random copolymer having a Shore D hardness of at least 60, (B) an unsaturated fatty acid, and (C) a basic inorganic metal compound capable of neutralizing acid groups in components A and B. The golf ball has a good rebound, a good feel on impact, and excellent scuff resistance.
|
1. A golf ball comprising a core and a cover of one or more layer, wherein the core is made of a material obtained by molding under heat a rubber composition comprising (a) a base rubber containing polybutadiene having a stress relaxation time (T80), defined as the time in seconds from the moment when rotation is stopped immediately after measurement of the ML1+4 (100° C.) value (the Mooney viscosity measured at 100° C. in accordance with ASTM D-1646-96) that is required for the ML1-+4 value to decrease 80%, of 3.5 or less, (b) an unsaturated carboxylic acid and/or a metal salt thereof, and (c) an organic peroxide, and wherein at least one layer of the cover is made of a material obtained by molding a mixture comprising: (A) 100 parts by weight of a metal ion-neutralized olefin-unsaturated carboxylic acid random copolymer having a Shore D hardness of at least 60; (B) 5 to 60 parts by weight of an unsaturated fatty acid; and (C) 1 to 10 parts by weight of a basic inorganic metal compound capable of neutralizing acid groups in components A and B. 2. The golf ball of claim 1, wherein the rubber composition further comprises (d) an organosulfur compound. 3. The golf ball of claim 1, wherein the polybutadiene having a stress relaxation time (T80) of 3.5 or less accounts for at least 40 wt % of the base rubber. 4. The golf ball of claim 1, wherein the polybutadiene having a stress relaxation time (T80) of 3.5 or less is a polybutadiene prepared using a rare-earth catalyst. 5. The golf ball of claim 1, wherein the polybutadiene having a stress relaxation time (T80) of 3.5 or less is a polybutadiene prepared by polymerization using a rare-earth catalyst, followed by terminal modification. 6. The golf ball of claim 1, wherein an outermost layer of the cover is made of the material obtained by molding the mixture of components A to C. 7. The golf ball of claim 1, wherein the mixture has a melt mass flow rate of at least 2.0 g/10 min. 8. The golf ball of claim 1, wherein the unsaturated fatty acid serving as component B is at least one selected from the group consisting of oleic acid, elaidic acid, erucic acid, linoleic acid and linolenic acid. 9. The golf ball of claim 1, wherein the basic inorganic metal compound serving as component C is calcium hydroxide.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to a golf ball having an excellent rebound. Efforts to confer golf balls with an excellent rebound have until now focused on and attempted to optimize one or more indicator of the polybutadiene used as the base rubber, such as the Mooney viscosity, polymerization catalyst, solvent viscosity and molecular weight distribution. See, for example, Patent Document 1: JP-A 2004-292667; Patent Document 2: U.S. Pat. No. 6,818,705; Patent Document 3: JP-A 2002-355336; Patent Document 4: JP-A 2002-355337; Patent Document 5: JP-A 2002-355338; Patent Document 6: JP-A 2002-355339; Patent Document 7: JP-A 2002-355340; and Patent Document 8: JP-A 2002-356581. For example, Patent Document 1 (JP-A 2004-292667) describes, as a base rubber for golf balls, a polybutadiene having a Mooney viscosity of 30 to 42 and a molecular weight distribution (Mw/Mn) of 2.5 to 3.8. Patent Document 2 (U.S. Pat. No. 6,818,705) describes, for the same purpose, a polybutadiene having a molecular weight of at least 200,000 and a resilience index of at least 40. However, because many golfers desire golf balls capable of traveling a longer distance, there exists a need for the development of golf balls having an even better rebound. Patent Document 1: JP-A 2004-292667 Patent Document 2: U.S. Pat. No. 6,818,705 Patent Document 3: JP-A 2002-355336 Patent Document 4: JP-A 2002-355337 Patent Document 5: JP-A 2002-355338 Patent Document 6: JP-A 2002-355339 Patent Document 7: JP-A 2002-355340 Patent Document 8: JP-A 2002-356581
|
<SOH> SUMMARY OF THE INVENTION <EOH>It is therefore an object of the present invention to provide a golf ball having an excellent rebound. As a result of extensive investigations, the inventor has discovered that, in a golf ball composed of a core and a cover of one or more layers, by having the core made of a material obtained by molding under heat a rubber composition which includes a base rubber containing a polybutadiene having a specific T 80 value, an unsaturated carboxylic acid and/or a metal salt thereof, and an organic peroxide, and by having at least one layer of the cover made of a material obtained by mixing in specific proportions and molding (A) a metal ion-neutralized olefin-unsaturated carboxylic acid random copolymer having a Shore D hardness of at least 60, (B) an unsaturated fatty acid and (C) a basic inorganic metal compound capable of neutralizing acid groups in foregoing components A and B, a good ball rebound is maintained. The golf ball of the invention has also been found to have a good feel on impact and an excellent scuff resistance. Accordingly, the invention provides the following golf balls. [1] A golf ball comprising a core and a cover of one or more layer, wherein the core is made of a material obtained by molding under heat a rubber composition comprising (a) a base rubber containing polybutadiene having a stress relaxation time (T 80 ), defined as the time in seconds from the moment when rotation is stopped immediately after measurement of the ML 1+4 (100° C.) value (the Mooney viscosity measured at 100° C. in accordance with ASTM D-1646-96) that is required for the ML 1+4 value to decrease 80%, of 3.5 or less, (b) an unsaturated carboxylic acid and/or a metal salt thereof, and (c) an organic peroxide, and wherein at least one layer of the cover is made of a material obtained by molding a mixture comprising: (A) 100 parts by weight of a metal ion-neutralized olefin-unsaturated carboxylic acid random copolymer having a Shore D hardness of at least 60; (B) 5 to 60 parts by weight of an unsaturated fatty acid; and (C) 1 to 10 parts by weight of a basic inorganic metal compound capable of neutralizing acid groups in components A and B. [2] The golf ball of [1], wherein the rubber composition further comprises (d) an organosulfur compound. [3] The golf ball of [1], wherein the polybutadiene having a stress relaxation time (T 80 ) of 3.5 or less accounts for at least 40 wt % of the base rubber. [4] The golf ball of [1], wherein the polybutadiene having a stress relaxation time (T 80 ) of 3.5 or less is a polybutadiene prepared using a rare-earth catalyst. [5] The golf ball of [1], wherein the polybutadiene having a stress relaxation time (T 80 ) of 3.5 or less is a polybutadiene prepared by polymerization using a rare-earth catalyst, followed by terminal modification. [6] The golf ball of [1], wherein an outermost layer of the cover is made of the material obtained by molding the mixture of components A to C. [7] The golf ball of [1], wherein the mixture has a melt mass flow rate of at least 2.0 g/10 min. [8] The golf ball of [1], wherein the unsaturated fatty acid serving as component B is at least one selected from the group consisting of oleic acid, elaidic acid, erucic acid, linoleic acid and linolenic acid. [9] The golf ball of [1], wherein the basic inorganic metal compound serving as component C is calcium hydroxide. detailed-description description="Detailed Description" end="lead"?
|
CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of copending application Ser. No. 11/324,297 filed on Jan. 4, 2006, the entire contents of which are hereby incorporated by reference. This application claims priority under 35 U.S.C. S119(a) on Patent Application No. 2007-173990 filed in Japan on Jul. 2, 2007, the entire contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION The present invention relates to a golf ball having an excellent rebound. Efforts to confer golf balls with an excellent rebound have until now focused on and attempted to optimize one or more indicator of the polybutadiene used as the base rubber, such as the Mooney viscosity, polymerization catalyst, solvent viscosity and molecular weight distribution. See, for example, Patent Document 1: JP-A 2004-292667; Patent Document 2: U.S. Pat. No. 6,818,705; Patent Document 3: JP-A 2002-355336; Patent Document 4: JP-A 2002-355337; Patent Document 5: JP-A 2002-355338; Patent Document 6: JP-A 2002-355339; Patent Document 7: JP-A 2002-355340; and Patent Document 8: JP-A 2002-356581. For example, Patent Document 1 (JP-A 2004-292667) describes, as a base rubber for golf balls, a polybutadiene having a Mooney viscosity of 30 to 42 and a molecular weight distribution (Mw/Mn) of 2.5 to 3.8. Patent Document 2 (U.S. Pat. No. 6,818,705) describes, for the same purpose, a polybutadiene having a molecular weight of at least 200,000 and a resilience index of at least 40. However, because many golfers desire golf balls capable of traveling a longer distance, there exists a need for the development of golf balls having an even better rebound. Patent Document 1: JP-A 2004-292667 Patent Document 2: U.S. Pat. No. 6,818,705 Patent Document 3: JP-A 2002-355336 Patent Document 4: JP-A 2002-355337 Patent Document 5: JP-A 2002-355338 Patent Document 6: JP-A 2002-355339 Patent Document 7: JP-A 2002-355340 Patent Document 8: JP-A 2002-356581 SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a golf ball having an excellent rebound. As a result of extensive investigations, the inventor has discovered that, in a golf ball composed of a core and a cover of one or more layers, by having the core made of a material obtained by molding under heat a rubber composition which includes a base rubber containing a polybutadiene having a specific T80 value, an unsaturated carboxylic acid and/or a metal salt thereof, and an organic peroxide, and by having at least one layer of the cover made of a material obtained by mixing in specific proportions and molding (A) a metal ion-neutralized olefin-unsaturated carboxylic acid random copolymer having a Shore D hardness of at least 60, (B) an unsaturated fatty acid and (C) a basic inorganic metal compound capable of neutralizing acid groups in foregoing components A and B, a good ball rebound is maintained. The golf ball of the invention has also been found to have a good feel on impact and an excellent scuff resistance. Accordingly, the invention provides the following golf balls. [1] A golf ball comprising a core and a cover of one or more layer, wherein the core is made of a material obtained by molding under heat a rubber composition comprising (a) a base rubber containing polybutadiene having a stress relaxation time (T80), defined as the time in seconds from the moment when rotation is stopped immediately after measurement of the ML1+4 (100° C.) value (the Mooney viscosity measured at 100° C. in accordance with ASTM D-1646-96) that is required for the ML1+4 value to decrease 80%, of 3.5 or less, (b) an unsaturated carboxylic acid and/or a metal salt thereof, and (c) an organic peroxide, and wherein at least one layer of the cover is made of a material obtained by molding a mixture comprising: (A) 100 parts by weight of a metal ion-neutralized olefin-unsaturated carboxylic acid random copolymer having a Shore D hardness of at least 60; (B) 5 to 60 parts by weight of an unsaturated fatty acid; and (C) 1 to 10 parts by weight of a basic inorganic metal compound capable of neutralizing acid groups in components A and B. [2] The golf ball of [1], wherein the rubber composition further comprises (d) an organosulfur compound. [3] The golf ball of [1], wherein the polybutadiene having a stress relaxation time (T80) of 3.5 or less accounts for at least 40 wt % of the base rubber. [4] The golf ball of [1], wherein the polybutadiene having a stress relaxation time (T80) of 3.5 or less is a polybutadiene prepared using a rare-earth catalyst. [5] The golf ball of [1], wherein the polybutadiene having a stress relaxation time (T80) of 3.5 or less is a polybutadiene prepared by polymerization using a rare-earth catalyst, followed by terminal modification. [6] The golf ball of [1], wherein an outermost layer of the cover is made of the material obtained by molding the mixture of components A to C. [7] The golf ball of [1], wherein the mixture has a melt mass flow rate of at least 2.0 g/10 min. [8] The golf ball of [1], wherein the unsaturated fatty acid serving as component B is at least one selected from the group consisting of oleic acid, elaidic acid, erucic acid, linoleic acid and linolenic acid. [9] The golf ball of [1], wherein the basic inorganic metal compound serving as component C is calcium hydroxide. DETAILED DESCRIPTION OF THE INVENTION The invention is described more fully below. The golf ball of the invention has a core and a cover of one or more layer. The core is not limited to only one layer, and may if necessary be composed of two or more layers. The core is made of a material obtained by molding under heat a rubber composition which includes the following components (a) to (c): (a) a base rubber containing polybutadiene having a stress relaxation time (T80), as defined below, of 3.5 or less, (b) an unsaturated carboxylic acid and/or a metal salt thereof, and (c) an organic peroxide. The stress relaxation time (T80) is the time in seconds, from the moment when rotor rotation is stopped immediately after measurement of the ML1+4 (100° C.) value (the Mooney viscosity measured at 100° C. in accordance with ASTM D-1646-96), that is required for the ML1+4 value to decrease 80%. The term “Mooney viscosity” used herein refers to an industrial indicator of viscosity as measured with a Mooney viscometer, which is a type of rotary plastometer. The unit symbol used is ML1+4 (100° C.), where “M” stands for Mooney viscosity, “L” stands for large rotor (L-type), “1+4” stands for a pre-heating time of 1 minute and a rotor rotation time of 4 minutes, and “100° C.” indicates that measurement was carried out at a temperature of 100° C. In the practice of the invention, the polybutadiene in above component (a) includes a polybutadiene having a stress relaxation time (T80) of 3.5 or less (which polybutadiene is sometimes abbreviated below as “BR1”). The T80 value is preferably 3.0 or less, more preferably 2.8 or less, and even more preferably 2.5 or less. The T80 value has a lower limit of preferably 1 or more, and more preferably 1.5 or more. At a T80 value of more than 3.5, the objects of the invention cannot be attained. On the other hand, if the T80 value is too small, problems may arise with workability. The foregoing polybutadiene BR1 has a Mooney viscosity (ML1+4 (100° C.)) which, while not subject to any particular limitation, is preferably at least 20 but not more than 80. It is recommended that the above polybutadiene BR1 have a cis-1,4 bond content of preferably 60%, more preferably at least 80%, even more preferably at least 90%, and most preferably at least 95%, and a 1,2-vinyl bond content of preferably at most 2%, more preferably at most 1.7%, even more preferably at most 1.5%, and most preferably at most 1.3%. At a cis-1,4 bond content or a 1,2-vinyl bond content outside of these ranges, the rebound may decrease. From the standpoint of rebound, it is preferable for the above polybutadiene BR1 used in the invention to be a polybutadiene synthesized using a rare-earth catalyst. A known rare-earth catalyst may be used for this purpose. Exemplary rare-earth catalysts include those made up of a combination of a lanthanide series rare-earth compound, an organoaluminum compound, an alumoxane, a halogen-bearing compound, and an optional Lewis base. Examples of suitable lanthanide series rare-earth compounds include halides, carboxylates, alcoholates, thioalcoholates and amides of atomic number 57 to 71 metals. Organoaluminum compounds that may be used include those of the formula AlR1R2R3 (wherein R1, R2 and R3 are each independently a hydrogen or a hydrocarbon group of 1 to 8 carbons). Preferred alumoxanes include compounds of the structures shown in formulas (I) and (II) below. The alumoxane association complexes described in Fine Chemical 23, No. 9, 5 (1994), J. Am. Chem. Soc. 115, 4971 (1993), and J. Am. Chem. Soc. 117, 6465 (1995) are also acceptable. In the above formulas, R4 is a hydrocarbon group having 1 to 20 carbon atoms, and n is 2 or a larger integer. Examples of halogen-bearing compounds that may be used include aluminum halides of the formula AlXnR3-n (wherein X is a halogen; R is a hydrocarbon group of 1 to 20 carbons, such as an alkyl, aryl or aralkyl; and n is 1, 1.5, 2 or 3); strontium halides such as Me3SrCl, Me2SrCl2, MeSrHCl2 and MeSrCl3; and other metal halides such as silicon tetrachloride, tin tetrachloride and titanium tetrachloride. The Lewis base can be used to form a complex with the lanthanide series rare-earth compound. Illustrative examples include acetylacetone and ketone alcohols. In the practice of the invention, the use of a neodymium catalyst in which a neodymium compound serves as the lanthanide series rare-earth compound is particularly advantageous because it enables a polybutadiene rubber having a high cis-1,4 bond content and a low 1,2-vinyl bond content to be obtained at an excellent polymerization activity. Preferred examples of such rare-earth catalysts include those mentioned in JP-A 11-35633. The polymerization of butadiene in the presence of a rare-earth catalyst may be carried out by bulk polymerization or vapor phase polymerization, either with or without the use of solvent, and at a polymerization temperature in a range of preferably from −30 to +150° C., and more preferably from 10 to 100° C. To manufacture golf balls of stable quality, it is desirable for the above-described polybutadiene BR1 used in the invention to be a terminal-modified polybutadiene obtained by polymerization using the above-described rare-earth catalyst, followed by the reaction of a terminal modifier with active end groups on the polymer. A known terminal modifier may be used for this purpose. Illustrative examples include compounds of types (1) to (6) below. (1) Halogenated organometallic compounds, halogenated metallic compounds and organometallic compounds of the general formulas R5nM′X4-n, M′X4, M′X3, R5nM′ (—R6—COOR7)4-n or R5nM′ (—R6—COR7)4-n (wherein R5 and R6 are each independently a hydrocarbon group of 1 to 20 carbons; R7 is a hydrocarbon group of 1 to 20 carbons which may contain pendant carbonyl or ester groups; M′ is a tin, silicon, germanium or phosphorus atom; X is a halogen atom; and n is an integer from 0 to 3); (2) heterocumulene compounds having on the molecule a Y=C=Z linkage (wherein Y is a carbon, oxygen, nitrogen or sulfur atom; and Z is an oxygen, nitrogen or sulfur atom); (3) three-membered heterocyclic compounds containing on the molecule the following bonds (wherein Y is an oxygen, nitrogen or sulfur atom); (4) halogenated isocyano compounds; (5) carboxylic acids, acid halides, ester compounds, carbonate compounds and acid anhydrides of the formula R8—(COOH)m, R9(COX)m, R10—(COO—R11), R12—OCOO—R13, R14—(COOCO—R15)m or (wherein R8 to R16 are each independently a hydrocarbon group of 1 to 50 carbons, X is a halogen atom, and m is an integer from 1 to 5); and (6) carboxylic acid metal salts of the formula R171M″ (OCOR18)4-1, R191M″ (OCO—R20—COOR21)4-1 or (wherein R17 to R23 are each independently a hydrocarbon group of 1 to 20 carbons, M″ is a tin, silicon or germanium atom, and the letter l is an integer from 0 to 3). Specific examples of the above terminal modifiers (1) to (6) and methods for their reaction are described in, for example, JP-A 11-35633 and JP-A 7-268132. In the practice of the invention, the above-described polybutadiene BR1 is included within the base rubber and accounts for preferably at least 40 wt %, more preferably at least 50 wt %, even more preferably at least 60 wt %, and even up to 100 wt %, of the base rubber. If this proportion is too low, the rebound may decrease. No particular limitation is imposed on rubber compounds other than BR1 which may be included in the base rubber. For example, polybutadiene rubbers having a stress relaxation time T80 of more than 3.5 may be included, as can also other rubber compounds such as styrene-butadiene rubbers (SBR), natural rubbers, polyisoprene rubbers and ethylene-propylene-diene rubbers (EPDM). These may be used individually or as combinations of two or more thereof. The Mooney viscosity of such additional rubbers included in the base rubber, while not subject to any particular limitation, is preferably at least 20 but preferably not more than 80. Rubbers synthesized with a group VIII catalyst may be used as such additional rubbers included in the base rubber. Exemplary group VIII catalysts include the following nickel catalysts and cobalt catalysts. Examples of suitable nickel catalysts include single-component systems such as nickel-kieselguhr, binary systems such as Raney nickel/titanium tetrachloride, and ternary systems such as nickel compound/organometallic compound/boron trifluoride etherate. Exemplary nickel compounds include reduced nickel on a carrier, Raney nickel, nickel oxide, nickel carboxylate and organonickel complex salts. Exemplary organometallic compounds include trialkylaluminum compounds such as triethylaluminum, tri-n-propylaluminum, triisobutylaluminum and tri-n-hexylaluminum; alkyllithium compounds such as n-butyllithium, sec-butyllithium, tert-butyllithium and 1,4-dilithiumbutane; and dialkylzinc compounds such as diethylzinc and dibutylzinc. Examples of suitable cobalt catalysts include cobalt and cobalt compounds such as Raney cobalt, cobalt chloride, cobalt bromide, cobalt iodide, cobalt oxide, cobalt sulfate, cobalt carbonate, cobalt phosphate, cobalt phthalate, cobalt carbonyl, cobalt acetylacetonate, cobalt diethyldithiocarbamate, cobalt anilinium nitrite and cobalt dinitrosyl chloride. It is particularly advantageous to use these compounds in combination with, for example, a dialkylaluminum monochloride such as diethylaluminum monochloride or diisobutylaluminum monochloride; a trialkylaluminum such as triethylaluminum, tri-n-propylaluminum, triisobutylaluminum or tri-n-hexylaluminum; an alkylaluminum sesquichloride such as ethylaluminum sesquichloride; or aluminum chloride. Polymerization using the above group VIII catalysts, and particularly a nickel or cobalt catalyst, can be carried out by a process in which, typically, the catalyst is continuously charged into a reactor together with a solvent and butadiene monomer, and the reaction conditions are suitably selected, such as a reaction temperature in a range of 5 to 60° C. and a reaction pressure in a range of atmospheric pressure to 70 plus atmospheres, so as to yield a product having the above-indicated Mooney viscosity. Above component (b) may be an unsaturated carboxylic acid, specific examples of which include acrylic acid, methacrylic acid, maleic acid and fumaric acid. Acrylic acid and methacrylic acid are especially preferred. Alternatively, it may be the metal salt of an unsaturated carboxylic acid, examples of which include the zinc and magnesium salts of unsaturated fatty acids such as zinc dimethacrylate and zinc diacrylate. The use of zinc diacrylate is especially preferred. It is recommended that the content of above component (b) per 100 parts by weight of the base rubber be preferably at least 10 parts by weight, and more preferably at least 15 parts by weight, but preferably not more than 60 parts by weight, more preferably not more than 50 parts by weight, even more preferably not more than 45 parts by weight, and most preferably not more than 40 parts by weight. Too much component (b) will make the material molded under heat from the rubber composition too hard, giving the golf ball an unpleasant feel on impact. On the other hand, too little will result in a lower rebound. Above component (c) may be a commercially available product, suitable examples of which include Percumyl D (produced by NOF Corporation), Perhexa 3C (NOF Corporation) and Luperco 231XL (Atochem Co.). If necessary, a combination of two or more different organic peroxides may be used. It is recommended that the amount of component (c) per 100 parts by weight of the base rubber be preferably at least 0.1 part by weight, and more preferably at least 0.3 part by weight, but preferably not more than 5 parts by weight, more preferably not more than 4 parts by weight, even more preferably not more than 3 parts by weight, and most preferably not more than 2 parts by weight. Too much or too little component (c) may make it impossible to obtain a suitable hardness distribution, resulting in a poor feel on impact, durability and rebound. To further improve rebound, it is desirable for the rubber composition in the invention to include also the following component (d): (d) an organosulfur compound. Examples of such organosulfur compounds include thiophenols, thionaphthols, halogenated thiophenols, and metal salts thereof. Specific examples include the zinc salts of pentachlorothiophenol, pentafluorothiophenol, pentabromothiophenol and p-chlorothiophenol; and diphenylpolysulfides, dibenzylpolysulfides, dibenzoylpolysulfides, dibenzothiazoylpolysulfides and dithiobenzoylpolysulfides having 2 to 4 sulfurs. These may be used singly or as combinations of two or more thereof. Diphenyldisulfide and/or the zinc salt of pentachlorothiophenol are especially preferred. It is recommended that the amount of component (d) included per 100 parts by weight of the base rubber be preferably at least 0.1 part by weight, more preferably at least 0.2 part by weight, and even more preferably at least 0.5 part by weight, but preferably not more than 5 parts by weight, more preferably not more than 4 parts by weight, and even more preferably not more than 3 parts by weight. Too much organosulfur compound may make the material molded under heat from the rubber composition too soft, whereas too little may make an improved rebound difficult to achieve. The rubber composition in the invention may additionally include such additives as inorganic fillers and antioxidants. Illustrative examples of suitable inorganic fillers include zinc oxide, barium sulfate and calcium carbonate. The amount included per 100 parts by weight of the base rubber is preferably at least 5 parts by weight, more preferably at least 7 parts by weight, even more preferably at least 10 parts by weight, and most preferably at least 13 parts by weight, but preferably not more than 80 parts by weight, more preferably not more than 50 parts by weight, even more preferably not more than 45 parts by weight, and most preferably not more than 40 parts by weight. Too much or too little inorganic filler may make it impossible to obtain a proper golf ball weight and a suitable rebound. To increase the rebound, it is desirable for the inorganic filler to include zinc oxide in an amount of at least 50 wt %, preferably at least 75 wt %, and most preferably 100 wt % (where the zinc oxide accounts for 100% of the inorganic filler). The zinc oxide has an average particle size (by air permeametry) of preferably at least 0.01 μm, more preferably at least 0.05 μm, and most preferably at least 0.1 μm, but preferably not more than 2 μm, and more preferably not more than 1 μm. Examples of suitable commercial antioxidants include 2,2′-methylenebis(4-methyl-6-t-butylphenol) (Nocrac NS-6, available from Ouchi Shinko Chemical Industry Co., Ltd.) and 2,2′-methylenebis(4-ethyl-6-t-butylphenol) (Nocrac NS-5, Ouchi Shinko Chemical Industry Co., Ltd.). To achieve a good rebound and durability, it is recommended that the amount of antioxidant included per 100 parts by weight of the base rubber be preferably more than 0 part by weight, more preferably at least 0.05 part by weight, even more preferably at least 0.1 part by weight, and most preferably at least 0.2 part by weight, but preferably not more than 3 parts by weight, more preferably not more than 2 parts by weight, even more preferably not more than 1 part by weight, and most preferably not more than 0.5 part by weight. The material molded under heat from the rubber composition in the present invention can be obtained by vulcanizing and curing the rubber composition using a method of the same sort as that used on prior-art rubber compositions for golf balls. Vulcanization may be carried, for example, at a temperature of from 100 to 200° C. for a period of 10 to 40 minutes. It is recommended that the core (hot-molded material) in the invention have a hardness difference, obtained by subtracting the JIS-C hardness at the center of the hot-molded material from the JIS-C hardness at the surface of the material, of preferably at least 15, more preferably at least 16, even more preferably at least 17, and most preferably at least 18, but preferably not more than 50, and more preferably not more than 40. Setting the hardness within this range is desirable for achieving a golf ball having a soft feel and a good rebound and durability. It is also recommended that the core (hot-molded material) in the invention have a deflection, when compressed under a final load of 1275 N (130 kgf) from an initial load of 98 N (10 kgf), of preferably at least 2.0 mm, more preferably at least 2.5 mm, and even more preferably at least 2.8 mm, but preferably not more than 6.0 mm, more preferably not more than 5.5 mm, even more preferably not more than 5.0 mm, and most preferably not more than 4.5 mm. Too small a deflection may worsen the feel of the ball on impact and, particularly on long shots such as with a driver in which the ball incurs a large deformation, may subject the ball to an excessive rise in spin, shortening the distance traveled by the ball. On the other hand, a hot-molded material that is too soft may deaden the feel of the golf ball when played and compromise the rebound of the ball, resulting in a shorter distance, and may give the ball a poor durability to cracking with repeated impact. It is recommended that the core have a diameter of preferably at least 30.0 mm, more preferably at least 32.0 mm, even more preferably at least 35.0 mm, and most preferably at least 37.0 mm, but preferably not more than 41.0 mm, more preferably not more than 40.5 mm, even more preferably not more than 40.0 mm, and most preferably not more than 39.5 mm. In particular, it is recommended that such a solid core in a solid two-piece golf ball have a diameter of preferably at least 37.0 mm, more preferably at least 37.5 mm, even more preferably at least 38.0 mm, and most preferably at least 38.5 mm, but preferably not more than 41.0 mm, more preferably not more than 40.5 mm, and even more preferably not more than 40.0 mm. Similarly, it is recommended that such a solid core in a solid three-piece golf ball have a diameter of preferably at least 30.0 mm, more preferably at least 32.0 mm, even more preferably at least 34.0 mm, and most preferably at least 35.0 mm, but preferably not more than 40.0 mm, more preferably not more than 39.5 mm, and even more preferably not more than 39.0 mm. It is also recommended that the core have a specific gravity of preferably at least 0.9, more preferably at least 1.0, and even more preferably at least 1.1, but preferably not more than 1.4, more preferably not more than 1.3, and even more preferably not more than 1.2. Next, in the present invention, at least one layer of the cover of one or more layers is made of a material obtained by molding a mixture composed of the following essential ingredients: (A) 100 parts by weight of a metal ion-neutralized olefin-unsaturated carboxylic acid random copolymer; (B) 5 to 60 parts by weight of an unsaturated fatty acid; and (C) 1 to 10 parts by weight of a basic inorganic metal compound capable of neutralizing acid groups in components A and B. The olefin in component A is generally one having at least 2 carbons, but not more than 8 carbons, and preferably not more than 6 carbons. Illustrative examples include ethylene, propylene, butene, pentene, hexene, heptene and octene. Ethylene is especially preferred. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid and fumaric acid. Acrylic acid and methacrylic acid are preferred. The random copolymer of the random copolymer metal salt used as component A may be obtained by random copolymerization of the above-mentioned ingredients according to a known method. It is recommended that the content of unsaturated carboxylic acid (acid content) included in the random copolymer be preferably at least 2 wt %, more preferably at least 6 wt %, and even more preferably at least 8 wt %, but preferably not more than 25 wt %, more preferably not more than 20 wt %, and even more preferably not more than 15 wt %. If the acid content is too low, the rebound resilience may decrease. On the other hand, if the acid content is too high, the processability may decrease. The metal ion-neutralized random copolymer used as component A may be obtained by neutralizing some of the acid groups on the random copolymer with metal ions. Illustrative examples of metal ions for neutralizing the acid groups include Na+, K+, Li+, Zn++, Cu++, Mg++, Ca++, Co++, Ni++ and Pb++. Of these, Na+, Li+, Zn++ and Mg++ are preferred, and Zn++ is especially recommended. The degree to which the random copolymer is neutralized by these metal ions is not subject to any particular limitation. The neutralization product may be obtained by a known method, such as one that involves introducing to the random copolymer a suitable compound, examples of which include formates, acetates, nitrates, carbonates, bicarbonates, oxides, hydroxides and alkoxides of the above metal ions. In the inventive golf ball, a binary polymer which is a metal ion neutralization product of an olefin-unsaturated carboxylic acid random copolymer is used in this way as component A. The reason is that, while using the subsequently described unsaturated fatty acid with the above-described metal ion-neutralized binary copolymer serving as component A is essential for imparting the inventive ball with a soft feel and an excellent scuff resistance, a binary polymer better plasticizes the overall cover material than does a ternary polymer, enabling a good moldability to be maintained. It is critical that the metal ion-neutralized olefin-unsaturated carboxylic acid random copolymer serving as component A have a Shore D hardness of preferably at least 60, more preferably at least 61, and even more preferably at least 62. Given that component A serves as the base resin of the cover material and that the material hardness of the base resin is largely responsible for the hardness, durability and scuff resistance of the ball, it is essential to set the Shore D hardness of component A within the foregoing range. Illustrative examples of the metal salt of a random copolymer serving as component A include Himilan 1605, Himilan 1706, Himilan AM7317, Himilan AM7318 and Himilan AM7315 (all products of DuPont-Mitsui Polychemicals Co., Ltd.), and Surlyn 7930, Surlyn 8150, Surlyn 8220 and Surlyn 9150 (all products of E.I. DuPont de Nemours & Co.). In the invention, the unsaturated fatty acid used as component B generally has one or more double bond on the molecule. Illustrative examples include those having one double bond, such as oleic acid (18 carbons), elaidic acid (the trans isomer of oleic acid) and erucic acid (22 carbons); those having two double bonds, such as linoleic acid (18 carbons); and those having three double bonds, such as linolenic acid (18 carbons). These fatty acids may be used singly or as combinations of two or more. The use of oleic acid is especially preferred. Above component B is included in an amount, per 100 parts by weight of component A, of at least 5 parts by weight, preferably at least 8 parts by weight, and more preferably at least 10 parts by weight. Use in a smaller amount may make it impossible to lower the hardness of the ionomer resin to the desired level. The upper limit in the amount of component B is 60 parts by weight or less, preferably 50 parts by weight or less, and more preferably 40 parts by weight or less. At an amount greater than this upper limit, uptake by the resin becomes difficult and bleeding tends to arise. The golf ball material of the invention includes as component C a basic inorganic metal compound capable of neutralizing acid groups on above components A and B. It neutralizes un-neutralized carboxyl groups within the ionomer resin and carboxyl groups in component B, thereby forming a metal salt. This results in strong crosslinkages, enhancing the scuff resistance. In the golf ball of the invention, as noted above, an unsaturated fatty acid is included as component B. The amount of component B is relatively small, which should help avoid problems such as molding defects. The reason for using an unsaturated fatty acid having one or more double bond on the molecule is that such fatty acids exhibit a much larger ionomer resin hardness-lowering effect than saturated fatty acids having no double bonds (e.g., stearic acid (18 carbons)). Component C of the invention is a basic inorganic metal compound capable of neutralizing acid groups in above components A and B, thus enabling the rebound resilience and processability to be freely controlled. Illustrative examples of the metal ions used in the basic inorganic metal compound include Li+, Na+, K+, Ca++, Mg++, Zn++, Al+++, Ni+, Fe++, Fe+++, Cu++, Mn++, Sn++, Pb++ and Co++. Basic inorganic fillers containing these metal ions may be used as the inorganic metal compound. Specific examples include magnesium oxide, magnesium hydroxide, magnesium carbonate, zinc oxide, sodium hydroxide, sodium carbonate, calcium oxide, calcium hydroxide, lithium hydroxide and lithium carbonate. The use of calcium hydroxide, which has a high reactivity with the ionomer resin, is especially preferred. Above component C is included in an amount, per 100 parts by weight of component A, of at least 1 part by weight, preferably at least 1.2 parts by weight, and more preferably at least 1.5 parts by weight. Below this amount, the degree of neutralization falls short and a sufficient rebound resilience cannot be achieved. The upper limit in the amount of component C per 100 parts by weight of component A is not more than 10 parts by weight, preferably not more than 7 parts by weight, and more preferably not more than 6 parts by weight. Other materials may be suitably included in the mixture of components A to C, although it is recommended that the mixture have a melt mass flow rate (measured in accordance with JIS-K7210 at a test temperature of 190° C. and under a test load of 21 N (2.16 kgf)) of preferably at least 2.0 g/10 min, and more preferably at least 2.5 g/10 min, but preferably not more than 6 g/10 min, and more preferably not more than 5 g/10 min. If the melt mass flow rate of the hot mixture is too low, the processability will markedly decline. Various additives may be optionally included in the mixture. For example, when the mixture is to be used as a cover material, additives such as pigments, dispersants, antioxidants, ultraviolet absorbers and light stabilizers may be included therein. Moreover, to improve the feel of the ball on impact, in addition to the essential ingredients described above, various non-ionomeric thermoplastic elastomers may be included in the material of the invention. Examples of such non-ionomeric thermoplastic elastomers include olefin elastomers, styrene elastomers, ester elastomers, and urethane elastomers. The use of olefin elastomers and styrene elastomers is especially preferred. The mixing method used to obtain the above mixture is not subject to any particular limitation. For example, mixture may be carried out at a heating temperature of from 150 to 250° C. using as the mixing apparatus an internal mixer such as a kneading-type twin-screw extruder, a Banbury mixer or a kneader. No limitation is place on the method of incorporating the various additives other than above essential ingredients A to C. Examples include a method in which the additives are compounded with the above essential ingredients and simultaneously mixed under applied heat, and a method in which the essential ingredients are first mixed under heating, then the optional additives are added, followed by additional mixing under applied heat. In particular, when a co-rotating twin-screw extruder is used, the unsaturated fatty acid may be injected from various vent ports on the twin-screw extruder using a plunger-type pump. The basic inorganic metal compound may be added from any desired point using a side feed. To obtain the cover in the invention, use may be made of a method which involves placing within a mold a single-layer core or a multi-layer core of two or more layers that has been pre-fabricated according to the type of ball, mixing and melting the above mixture under applied heat, and injection-molding the molten mixture so as to encase the core within the desired cover. In this way, the cover-forming operation can be carried out in a state that ensures an outstanding heat stability, flow and moldability, enabling the golf ball ultimately obtained to have a high rebound and also a good feel on impact and excellent scuff resistance. Alternatively, the method used to form the cover may be one in which first a pair of hemispherical half-cups is molded from the cover material of the invention, following which the half-cups are placed over a core and molded under pressure at 120 to 170° C. for 1 to 5 minutes. In the practice of the invention, the cover is not limited to one layer only, and may instead be formed with a multilayer structure of two or more layers. If the cover has one layer, the thickness is preferably from 0.5 to 3 mm. If the cover has two layers, it is preferable for the outer cover layer to have a thickness in a range of 0.5 to 2.0 mm and for the inner cover layer to have a thickness in a range of 0.5 to 2.0 mm. When the cover has a multilayer structure, the cover material of the invention may be used either at the inner side of the multilayer structure or in the outermost layer cover. However, in the present invention, use as the outermost layer is preferred. That is, when the cover is formed of two or more layers, to obtain a good feel and to make the scuff resistance even better, it is advantageous for a molded material obtained from the mixture containing above components A to C to be used as the chief material of the outermost layer. With regard to the cover hardness, it is desirable for the respective layers making up the cover (cover layers) to have a Shore D hardness of at least 40, and preferably at least 45, but not more than 60, and preferably not more than 58. The surface of the outermost layer of the cover may have a plurality of dimples formed thereon, and the cover may be administered various treatment, such as surface preparation, stamping and painting. In particular, the ease of operation involved in administering such surface treatment to a golf ball cover made of the cover material of the invention can be improved on account of the good moldability of the cover surface. The present invention provides a golf ball in which a material obtained by molding the above mixture is used in at least one cover layer. The type of golf ball is not subject to any particular limitation, provided the ball has a core and at least one cover layer. Exemplary golf balls include solid golf balls, such as two-piece golf balls having a solid core encased by a cover and multi-piece golf balls with three or more layers (e.g., three-piece solid golf balls); and thread-wound golf balls having a thread-wound core encased by a cover of one layer or having a multilayer structure of two or more layers. The golf ball of the invention, which can be manufactured so as to conform with the Rules of Golf for competitive play, may be produced to a ball diameter of not less than 42.67 mm and a weight of not more than 45.93 g. The golf ball of the invention may be suitably used in all competitive play, whether by amateur golfers having a head speed of 30 to 40 m/s or by professional golfers having a head speed of 45 m/s. The golf ball of the invention uses as the core a material of exceptional resilience that has been molded under heat from a rubber composition, as a result of which the ball as a whole has an excellent rebound. Moreover, the golf ball of the invention also has a good feel on impact and excellent scuff resistance while retaining a good flight performance. EXAMPLES The following Examples and Comparative Examples are provided by way of illustration and not by way of limitation. Examples 1 to 6, Comparative Examples 1 to 8 Using a core material composed primarily of the polybutadiene shown in Table 1 below, a solid core having a diameter of 35.3 mm, a weight of 27.1 g, and a deflection adjusted to 4.1 mm or 4.2 mm was produced. The deflection was the measured amount of deformation by the core when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf). TABLE 1 Core No. No. 1 No. 2 No. 3 No. 4 Formulation Polybutadiene EC140 100 (pbw) Polybutadiene BR51 100 Polybutadiene BR60 100 Polybutadiene BR01 100 Peroxide 0.8 0.8 0.8 0.8 Zinc oxide 5 5 5 5 Antioxidant 0.2 0.2 0.2 0.2 Zinc diacrylate 24 24 24 24 Zinc salt of 0.1 0.1 0.1 0.1 pentachlorothiophenol Barium sulfate 20.8 20.8 20.8 20.8 Properties Diameter (mm) 35.3 35.3 35.3 35.3 Weight (g) 27.1 27.1 27.1 27.1 Deflection (mm) 4.1 4.1 4.1 4.2 Details of the above formulation are provided below. Polybutadiene rubber: “EC140” (trade name), available from Firestone Polymers. Polymerized with a neodymium catalyst; Mooney viscosity, 43; T80 value, 2.3. Polybutadiene rubber: “BR51” (trade name), available from JSR Corporation. Polymerized with a neodymium catalyst; Mooney viscosity, 39; T80 value, 5.0. Polybutadiene rubber: “BR60” (trade name), available from Polimeri Srl. Polymerized with a neodymium catalyst; Mooney viscosity, 57; T80 value, 4.6. Polybutadiene rubber: “BROL” (trade name), available from JSR Corporation. Polymerized with a nickel catalyst; Mooney viscosity, 48; T80 value, 8.4. Peroxide: Dicumyl peroxide, available from NOF Corporation under the trade name “Percumyl D”. Zinc oxide: Available from Sakai Chemical Industry Co., Ltd. under the trade name “Sanshu Sanka Aen”; average particle size, 0.6 μm (air permeametry). Antioxidant: “Nocrac NS-6” (trade name), available from Ouchi Shinko Chemical Industry Co., Ltd. Zinc diacrylate:Available from Nippon Shokubai Co., Ltd. Barium sulfate: “Barico #100” (trade name), available from Hakusui Tech Co., Ltd. Next, an intermediate layer (inner cover layer) material of the composition shown in Table 2 was injection-molded to a thickness of 1.65 mm in a mold within which the above solid core (cores No. 1 to No. 4) had been placed. The cover material was then mixed in a co-rotating twin-screw extruder (screw diameter, 32 mm; L/D=32; motor capacity, 7.5 kw; with vacuum vent) at 200° C.; the resulting mixture was injected into a mold within which the intermediate layer material-encased core had been placed, and injection-molded to a cover thickness of 2.05 mm, thereby producing a three-piece solid golf ball having a diameter of 42.7 mm. The surface of the golf ball obtained in each example was coated with a non-yellowing urethane resin-based paint. The properties (initial velocity, feel on impact, scuff resistance, etc.) of the golf balls obtained in each example were evaluated as described below. The results are presented in Tables 2 and 3. TABLE 2 Example 1 2 3 4 5 6 Core Type No. 1 No. 1 No. 1 No. 1 No. 1 No. 1 Intermediate Hytrel 4047 100 100 100 100 100 100 layer formulation (pbw) Intermediate Material hardness (Shore D) 40 40 40 40 40 40 layer Specific gravity 1.12 1.12 1.12 1.12 1.12 1.12 properties Sphere Outside diameter (mm) 38.6 38.6 38.6 38.6 38.6 38.6 composed of core encased by intermediate layer Cover Component A Himilan 1706 100 100 100 formulation Himilan 1605 100 100 100 (pbw) Himilan 1601 Himilan 1557 Component B Oleic acid 20 30 40 20 30 40 Component C Calcium 1.83 3.41 5.2 3.03 4.92 5 hydroxide Titanium dioxide 4 4 4 4 4 4 Magnesium stearate Blue pigment 0.05 0.05 0.05 0.05 0.05 0.05 Cover Melt mass flow rate 4.0 4.3 5.9 3.8 4.8 6.9 properties (g/10 min) Cover hardness (Shore D) 50 50 46 58 56 54 Specific gravity 1.00 1.00 0.99 0.98 0.97 0.99 Ball Diameter (mm) 42.7 42.7 42.7 42.7 42.7 42.7 properties Weight (g) 45.4 45.4 45.4 45.3 45.1 45.4 Deflection (mm) 3.5 3.5 3.5 3.3 3.3 3.4 Initial velocity (m/s) 76.2 76.4 76.5 77.2 77.2 77 Scuff resistance (rating) 4.4 4.4 4.3 4.3 4.2 4.1 Feel on impact good good good good good good TABLE 3 Comparative Example 1 2 3 4 5 6 7 8 Core Type No. 1 No. 1 No. 1 No. 1 No. 2 No. 3 No. 4 No. 4 Intermediate Hytrel 4047 100 100 100 100 100 100 100 100 layer formulation (pbw) Intermediate Material hardness (Shore D) 40 40 40 40 40 40 40 40 layer Specific gravity 1.12 1.12 1.12 1.12 1.12 1.12 1.12 1.12 properties Sphere Outside diameter (mm) 38.6 38.6 38.6 38.6 38.6 38.6 38.6 38.6 composed of core encased by intermediate layer Cover Component A Himilan 1706 100 50 100 100 100 100 formulation Himilan 1605 100 50 (pbw) Himilan 1601 50 Himilan 1557 50 Component B Oleic acid 30 30 30 Component C Calcium 3.41 3.41 3.41 hydroxide Titanium dioxide 4 4 4 4 4 4 4 4 Magnesium stearate 2 2 2 2 2 Blue pigment 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Cover Melt mass flow rate 1.3 2.9 1.7 2.1 4.3 4.3 4.3 1.3 properties (g/10 min) Cover hardness (Shore D) 62 63 63 60 50 50 50 62 Specific gravity 0.99 0.97 0.98 0.97 1.00 1.00 1.00 0.99 Ball Diameter (mm) 42.7 42.7 42.7 42.7 42.7 42.7 42.7 42.7 properties Weight (g) 45.3 45.1 45.2 45.1 45.4 45.4 45.4 45.3 Deflection (mm) 3.2 3.1 3.1 3.3 3.5 3.5 3.6 3.3 Initial velocity (m/s) 77 77.4 77.6 77.1 76.2 76.2 76 76.6 Scuff resistance (rating) 4.6 4.1 4.2 3.7 4.4 4.4 4.4 4.6 Feel on impact NG NG NG NG good good good NG Details of the above formulation are provided below. (I) Hytrel 4047 (trade name): Thermoplastic polyether ester elastomer available from DuPont-Toray Co., Ltd. (Shore D hardness, 40). (II) Himilan 1706 (trade name): Ionomer resin of ethylene-methacrylic acid copolymer neutralized with zinc ions, available from DuPont-Mitsui Polychemicals Co., Ltd. (Shore D hardness, 64). (III) Himilan 1605 (trade name): Ionomer resin of ethylene-methacrylic acid copolymer neutralized with sodium ions, available from DuPont-Mitsui Polychemicals Co., Ltd. (Shore D hardness, 65). (IV) Himilan 1601 (trade name): Ionomer resin of ethylene-methacrylic acid copolymer neutralized with sodium ions, available from DuPont-Mitsui Polychemicals Co., Ltd. (Shore D hardness, 59). (V) Himilan 1557 (trade name): Ionomer resin of ethylene-methacrylic acid copolymer neutralized with zinc ions, available from DuPont-Mitsui Polychemicals Co., Ltd. (Shore D hardness, 59). (VI) Oleic acid: NAA-300 (trade name), available from NOF Corporation. (VII) Magnesium stearate: Nissan Magnesium Stearate (trade name), available from NOF Corporation. (VIII) Titanium oxide: Tipaque R550 (trade name), available from Ishihara Sangyo Kaisha, Ltd. (IX) Blue pigment: Ultramarine Blue EP-62 (trade name), available from Holliday Pigments. (X) Calcium hydroxide: CLS-B (trade name), available from Shiraishi Kogyo. [Evaluation of Cover Material Properties] Melt Mass Flow Rate The melt mass flow rate (or melt index) of the material, as measured in accordance with JIS-K7210 (test temperature, 190° C.; test load, 21 N (2.16 kgf). Material Hardnesses of Intermediate Layer and Cover Resin The Shore D hardnesses measured according to ASTM D-2240 are shown. [Evaluation of Ball Properties] Ball Deflection (mm) The amount of deformation (mm) by the golf ball when compressed under a final load of 1,275 N (130 kgf) from an initial load state of 98 N (10 kgf) was determined. Initial Velocity of Ball (m/s) The initial velocity (m/s) was measured using an initial velocity measuring apparatus of the same type as that of the official golf ball regulating-body—R&A (USGA), and in accordance with R&A (USGA) rules. Feel on Impact Sensory evaluations were carried out with a panel of ten amateur golfers having head speeds of 35 to 40 m/s and using W#1 clubs. Ratings were based on the following criteria. Good: At least 7 of the 10 golfers thought the ball had a good feel. Fair: Five or six of the 10 golfers thought the ball had a good feel. Poor: Four or fewer of the 10 golfers thought the ball had a good feel. Scuff Resistance A non-plated X-WEDGE 03 (loft, 52°) manufactured by Bridgestone Sports Co., Ltd. was set in a swing robot, and the ball was hit at a head speed of 33 m/s with the club face open about 30° from square. The surface state of the ball was then visually examined by three golfers having handicaps of 10 or less, and rated according to the following criteria. The average of the ratings obtained for each example is shown in the table. 5: Surface of ball is either completely unchanged or bears a slight imprint from club face. 4: Surface of ball bears a clear imprint from club face, but is not frayed. 3: Surface is conspicuously frayed and scuffed. 2: Surface is frayed and cracked. 1: Some dimples have been obliterated. It is apparent from the results in Tables 2 and 3 that the golf balls obtained in Examples 1 to 6 according to the invention had excellent rebound resilience, scuff resistance and feel on impact. By contrast, the balls obtained in Comparative Examples 1 to 8 had a poor feel and showed no improvement in scuff resistance.
|
A
|
A63
|
A63B
|
37
|
06
|
|||
11734194
|
US20070249872A1-20071025
|
PROCESS FOR HYDROGENATING AN ALDEHYDE
|
ACCEPTED
|
20071010
|
20071025
|
[]
|
C07C2914
|
["C07C2914"]
|
7381852
|
20070411
|
20080603
|
568
|
862000
|
68402.0
|
PRICE
|
ELVIS
|
[{"inventor_name_last": "Komplin", "inventor_name_first": "Glenn", "inventor_city": "Katy", "inventor_state": "TX", "inventor_country": "US"}, {"inventor_name_last": "Smegal", "inventor_name_first": "John", "inventor_city": "Houston", "inventor_state": "TX", "inventor_country": "US"}]
|
The present invention relates to a process for hydrogenating an aldehyde. An aldehyde is contacted with a catalyst comprising a support containing at least 95% α-alumina and non-support metals dispersed on the surface of the support. The non-support metals comprise nickel and/or one or more compounds thereof and molybdenum and/or one or more compounds thereof. The nickel and/or one or more compounds thereof comprise from 3 wt. % to 9 wt. % of the catalyst, by metallic weight, and the molybdenum and/or one or more compounds thereof comprise from 1 wt. % to 4 wt. % of the catalyst, by metallic weight.
|
1. A process for hydrogenating an aldehyde, comprising: contacting an aldehyde with a catalyst in the presence of hydrogen where the catalyst is comprised of a support and non-support metal components dispersed on the surface of the support, the support containing at least about 95% α-alumina as measured by powder x-ray diffraction, and the non-support metal components comprise nickel and/or one or more compounds thereof and molybdenum and/or one or more compounds thereof, where the nickel and/or one or more compounds thereof comprises from about 3 wt. % to about 9 wt. % of the catalyst, by metallic weight, and the molybdenum and/or one or more compounds thereof comprises from about 1 wt. % to about 4 wt. %, by metallic weight, of the catalyst. 2. The process of claim 1 wherein non-support metal components other than nickel and molybdenum comprise up to about 1 wt. % of the catalyst, by metallic weight. 3. The process of claim 1 wherein the non-support metal components do not include ruthenium, platinum, or palladium. 4. The process of claim 1 wherein the non-support metal components consist essentially of nickel and/or one or more compounds thereof and molybdenum and/or one or more compounds thereof. 5. The process of claim 1 wherein the catalyst has a N2 BET surface area of from about 12 m2/g to about 30 m2/g. 6. The process of claim 1 wherein the catalyst has a pore size distribution having a median pore diameter of from about 1300 Å to about 1700 Å as measured by mercury porosimetry at a 140° contact angle. 7. The process of claim 1 wherein the nickel content of the catalyst, by metallic weight, is equal to or greater than the molybdenum content of the catalyst, by metallic weight. 8. The process of claim 1 wherein the weight ratio of nickel to molybdenum, by metallic weight, is from about 1:1 to about 3:1. 9. The process of claim 1 wherein the catalyst has a crush strength of at least about 2.3 kg/mm. 10. The process of claim 1 wherein the catalyst support is comprised of at most about 0.6 wt. % silica as measured by x-ray fluorescence. 11. The process of claim 1 wherein the aldehyde is a hydroxyaldehyde. 12. The process of claim 11 wherein the hydroxyaldehyde is 3-hydroxypropionaldehyde. 13. The process of claim 12 wherein the catalyst has an activity sufficient to convert 3-hydroxypropionaldehyde at a rate of at least 30 ml 3-hydroxypropionaldehyde/catalyst ml.hr at a temperature of from 50° C. to 90° C. at a pH of from 4.0 to 6.5, and at a hydrogen partial pressure of from 6.9 MPa to 11 MPa after at least 24 hours of catalyzing hydrogenation of 3-hydroxypropionaldehyde at a temperature of from 50° C. to 90° C., at a pH of from 4.0 to 6.5, and at a hydrogen partial pressure of from 6.9 MPa to 11 MPa. 14. The process of claim 12 wherein the 3-hydroxypropionaldehyde is in an aqueous solution where the 3-hydroxypropionaldehyde comprises at most about 15 wt. % of the aqueous solution. 15. The process of claim 12 wherein the 3-hydroxypropionaldehyde is hydrogenated to 1,3-propanediol under a hydrogen partial pressure of from about 6.9 MPa to about 11 MPa, at a temperature of from about 40° C. to about 190° C., and at a pH of less than about 6.5. 16. The process of claim 1 wherein the aldehyde is hydrogenated under a hydrogen partial pressure of from about 6.9 MPa to about 11 MPa, at a temperature of from about 40° C. to about 190° C., and at a pH of less than about 6.5. 17. The process of claim 1 wherein the catalyst further comprises from about 0.1 wt. % to about 1 wt. % cobalt and/or one or more compounds thereof, by metallic weight. 18. The process of claim 1 wherein the catalyst comprises at most about 8 wt. % nickel and molybdenum by combined metallic weight. 19. The process of claim 1 wherein the aldehyde is contacted with the catalyst in the presence of hydrogen at a pH of at most about 6.5. 20. The process of claim 1 wherein the aldehyde is contacted with the catalyst in the presence of hydrogen at a temperature of from about 40° C. to about 190° C. 21. The process of claim 1, wherein the aldehyde is provided for contact with the catalyst by converting an acetal to the aldehyde. 22. The process of claim 21 wherein the acetal is present in a hydrogenation reaction product.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1,3-propanediol (PDO) is a compound having multiple uses. It is used as a monomer unit in the production of polyesters and polyurethanes that are useful as films and as fibers for carpets and textiles. It is also useful as an engine coolant. PDO may be prepared from ethylene oxide (EO) in a process involving two primary reactions. First, EO and synthesis gas (H 2 /CO) are catalytically hydroformylated to form 3-hydroxypropionaldehyde (HPA) in an organic solvent. The HPA is extracted from the solvent with water to form an aqueous solution of HPA, and the aqueous solution of HPA is then hydrogenated to form PDO. The hydrogenation of HPA to PDO is performed using a hydrogenation catalyst. The hydrogenation catalyst should desirably have several features: 1) it should be highly active over an extended period of time; 2) it should cause the hydrogenation to be highly selective to the formation of PDO, rather than other compounds; 3) it should have a long catalyst life; 4) it should not be discharged into the PDO product stream; and 5) it should be economically cost effective, preferably using inexpensive components and, if required, as few expensive components as possible. According to Hatch et al., U.S. Pat. No. 2,434,110, especially preferred catalysts for hydrogenating HPA to PDO are Raney nickel and Adkin's copper-chromium oxide. Hatch et al. also disclose that other suitable catalysts for hydrogenating HPA to PDO include catalytically active compounds of metals such as Fe, Co, Cu, Pd, Zr, Ti, Th, V, Ta, Ag, Mo, and Al. Slurry catalysts such as Raney nickel are known to have high activity and selectivity in converting HPA to PDO as a result of the homogeneous distribution of the catalyst in the hydrogenation reaction mixture. Suspended or slurry catalysts, such as Raney nickel, however, are susceptible to being discharged into the PDO product stream in the form of soluble compounds, necessitating additional steps to purify the PDO product stream. Haas et al., U.S. Pat. No. 6,232,511, discloses that a supported ruthenium catalyst is useful in the hydrogenation of HPA to PDO, and avoids the problem of the metallic portion of the catalyst polluting the PDO product stream. Use of the supported ruthenium catalyst in a fixed-bed is preferred. Ruthenium and other noble metals such as platinum or palladium, however, are very expensive, and ruthenium and other noble metal based catalysts are not commercially attractive, especially for large scale continuous operations. Arhancet et al. U.S. Pat. Nos. 5,945,570 and 6,342,464, disclose a hydrogenation catalyst for hydrogenating HPA to PDO that is a bulk metal catalyst. The bulk metal catalyst includes 25 to 60 wt. % nickel and 5 to 20 wt. % molybdenum bound together with a binder made up of oxides of silicon, and silicates and oxides of zinc, zirconium, calcium, magnesium and/or aluminum. The catalyst is particulate and may be used in a fixed bed hydrogenation reactor such as a trickle bed reactor. Bulk metal catalysts, however, are subject to breaking into catalytic fines over an extended period of use, and may lack sufficient physical stability to be used in large scale long-term continuous operations. In short, hydrogenation catalysts in the art formed of economically advantageous non-noble catalytic metals either do not exhibit sufficient hydrogenation activity over an extended period of time, are discharged into the product stream requiring additional steps to purify the product stream, or are not sufficiently physically stable to be utilized in an industrial scale continuous long-term aldehyde hydrogenation process.
|
<SOH> SUMMARY OF THE INVENTION <EOH>In one aspect, the present invention provides a process for hydrogenating an aldehyde comprising contacting an aldehyde with a catalyst in the presence of hydrogen where the catalyst is comprised of a support and non-support metal components dispersed on the surface of the support, the support containing at least 95% α-alumina as measured by powder x-ray diffraction, and the non-support metal components comprise nickel and/or one or more compounds thereof and molybdenum and/or one or more compounds thereof, where the nickel and/or one or more compounds thereof comprises from 3 wt. % to 9 wt. % of the catalyst, by metallic weight, and the molybdenum and/or one or more compounds thereof comprises from 1 wt. % to 4 wt. %, by metallic weight, of the catalyst. detailed-description description="Detailed Description" end="lead"?
|
This application claims the benefit of the priority date of U.S. Provisional Application Ser. No. 60/791,774 filed Apr. 13, 2006. FIELD OF THE INVENTION The present invention relates to a process for hydrogenating an aldehyde. More particularly, the present invention relates to a process for hydrogenating an aldehyde by contacting the aldehyde with a catalyst in the presence of hydrogen, where the catalyst is comprised of a support containing at least 95% α-alumina, and non-support metals comprising nickel and/or one or more compounds thereof and molybdenum and/or one or more compounds thereof. BACKGROUND OF THE INVENTION 1,3-propanediol (PDO) is a compound having multiple uses. It is used as a monomer unit in the production of polyesters and polyurethanes that are useful as films and as fibers for carpets and textiles. It is also useful as an engine coolant. PDO may be prepared from ethylene oxide (EO) in a process involving two primary reactions. First, EO and synthesis gas (H2/CO) are catalytically hydroformylated to form 3-hydroxypropionaldehyde (HPA) in an organic solvent. The HPA is extracted from the solvent with water to form an aqueous solution of HPA, and the aqueous solution of HPA is then hydrogenated to form PDO. The hydrogenation of HPA to PDO is performed using a hydrogenation catalyst. The hydrogenation catalyst should desirably have several features: 1) it should be highly active over an extended period of time; 2) it should cause the hydrogenation to be highly selective to the formation of PDO, rather than other compounds; 3) it should have a long catalyst life; 4) it should not be discharged into the PDO product stream; and 5) it should be economically cost effective, preferably using inexpensive components and, if required, as few expensive components as possible. According to Hatch et al., U.S. Pat. No. 2,434,110, especially preferred catalysts for hydrogenating HPA to PDO are Raney nickel and Adkin's copper-chromium oxide. Hatch et al. also disclose that other suitable catalysts for hydrogenating HPA to PDO include catalytically active compounds of metals such as Fe, Co, Cu, Pd, Zr, Ti, Th, V, Ta, Ag, Mo, and Al. Slurry catalysts such as Raney nickel are known to have high activity and selectivity in converting HPA to PDO as a result of the homogeneous distribution of the catalyst in the hydrogenation reaction mixture. Suspended or slurry catalysts, such as Raney nickel, however, are susceptible to being discharged into the PDO product stream in the form of soluble compounds, necessitating additional steps to purify the PDO product stream. Haas et al., U.S. Pat. No. 6,232,511, discloses that a supported ruthenium catalyst is useful in the hydrogenation of HPA to PDO, and avoids the problem of the metallic portion of the catalyst polluting the PDO product stream. Use of the supported ruthenium catalyst in a fixed-bed is preferred. Ruthenium and other noble metals such as platinum or palladium, however, are very expensive, and ruthenium and other noble metal based catalysts are not commercially attractive, especially for large scale continuous operations. Arhancet et al. U.S. Pat. Nos. 5,945,570 and 6,342,464, disclose a hydrogenation catalyst for hydrogenating HPA to PDO that is a bulk metal catalyst. The bulk metal catalyst includes 25 to 60 wt. % nickel and 5 to 20 wt. % molybdenum bound together with a binder made up of oxides of silicon, and silicates and oxides of zinc, zirconium, calcium, magnesium and/or aluminum. The catalyst is particulate and may be used in a fixed bed hydrogenation reactor such as a trickle bed reactor. Bulk metal catalysts, however, are subject to breaking into catalytic fines over an extended period of use, and may lack sufficient physical stability to be used in large scale long-term continuous operations. In short, hydrogenation catalysts in the art formed of economically advantageous non-noble catalytic metals either do not exhibit sufficient hydrogenation activity over an extended period of time, are discharged into the product stream requiring additional steps to purify the product stream, or are not sufficiently physically stable to be utilized in an industrial scale continuous long-term aldehyde hydrogenation process. SUMMARY OF THE INVENTION In one aspect, the present invention provides a process for hydrogenating an aldehyde comprising contacting an aldehyde with a catalyst in the presence of hydrogen where the catalyst is comprised of a support and non-support metal components dispersed on the surface of the support, the support containing at least 95% α-alumina as measured by powder x-ray diffraction, and the non-support metal components comprise nickel and/or one or more compounds thereof and molybdenum and/or one or more compounds thereof, where the nickel and/or one or more compounds thereof comprises from 3 wt. % to 9 wt. % of the catalyst, by metallic weight, and the molybdenum and/or one or more compounds thereof comprises from 1 wt. % to 4 wt. %, by metallic weight, of the catalyst. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a process for hydrogenating an aldehyde, particularly hydroxyaldehydes, and most particularly HPA, by contacting the aldehyde with a catalyst in the presence of hydrogen. The catalyst is a supported catalyst that is particularly useful as a fixed-bed catalyst. The catalyst includes a support containing at least 95% α-alumina that provides excellent resistance against crushing and catalyst breakdown into fines. The catalyst is selective to hydrogenation of the aldehyde relative to catalysts having more acidic supports, e.g. silicas and transition aluminas such as gamma, delta, theta, and kappa aluminas, since the relatively non-acidic α-alumina support is less likely to catalyze the formation of acetals from the aldehyde. The catalyst comprises non-support catalytically active metal components nickel and/or one or more compounds thereof and molybdenum and/or one or more compounds thereof. The non-support catalytically active metal components are dispersed on the α-alumina support. The catalyst is effective to hydrogenate an aldehyde at a commercially acceptable rate despite the relatively small total quantity of catalytically active metal components that can be loaded on the α-alumina support—even though the metal components are not required to include highly active hydrogenation catalytic noble metals such as ruthenium, platinum, or palladium. The catalyst of the present invention provides significant economic advantage over other aldehyde, and particularly HPA, hydrogenation catalysts since relatively small amounts of relatively inexpensive active catalyst metal components are required to provide long-term hydrogenation activity at relatively high hydrogenation rates, and the catalyst has a long life due to its physical stability in combination with its long-term catalytic activity. In the process of the present invention, a feed comprising an aldehyde is contacted with hydrogen and a hydrogenation catalyst in a hydrogenation reactor, the catalyst comprising a support and non-support metal components located on the support, to hydrogenate the aldehyde to an alcohol, diol, triol, or polyol. The catalyst support is comprised of at least 95 % α-alumina as measured by powder x-ray diffraction. The catalyst non-support metal components are nickel and/or one or more compounds thereof, and molybdenum and/or one or more compounds thereof. The aldehyde may be any aldehyde that may be hydrogenated to an alcohol, diol, triol, or polyol. In one embodiment, the aldehyde may be a straight or branched chain aliphatic aldehyde. In an embodiment, the straight or branched chain aliphatic aldehyde may comprise at most 8 carbon atoms, or may contain from 2 to 6 carbon atoms. In an embodiment, the aldehyde is a 3-hydroxyaldehyde, i.e. a compound of the general formula R2C(OH)—C(R)2—CH═O wherein each R independently may be a hydrogen atom or may jointly) be a hydrocarbon group that is substituted or unsubstituted, and/or aliphatic or aromatic. Each group R may independently vary in size, for instance, from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms. In addition, they may bear one or more substituents selected from hydroxyl, alkoxy, carbonyl, carboxy, amino, cyano, mercapto, phosphino, phosphonyl, and or silyl groups, and/or one or more halogen atoms. Preferred 3-hydroxyaldehydes are those having in total from 3 to 12 carbon atoms, and more preferably from 3 to 8 carbon atoms. Most preferably the 3-hydroxyaldehyde is HPA, i.e. wherein each R is a hydrogen atom. The feed may be a solution containing the aldehyde where the solution may be an aqueous solution comprising at least 50 wt. %, or at least 70 wt. %, or at least 90 wt. %, or at least 95 wt. % water based on the weight of the aqueous feed solution, or an organic solution comprising at least 50 wt. %, or at least 70 wt. %, or at least 90 wt. %, or at least 95 wt. % of one or more organic solvents based on the weight of the organic feed solution. The aldehyde is preferably soluble in the feed solution, e.g. if the feed solution is aqueous the aldehyde is preferably soluble in the aqueous feed solution, and if the feed solution is organic the aldehyde is preferably soluble in the organic feed solution. In an embodiment, the aldehyde may be subject to dehydration under conditions for hydrogenating the aldehyde, and the feed solution may contain at least 1 wt. %, or at least 5 wt. %, or at least 20 wt. %, or at least 70 wt. % of water, where the water may inhibit dehydration of the aldehyde under hydrogenation conditions. The feed solution may contain at least 0.1 wt. % of the aldehyde, at least 0.2 wt. % of the aldehyde, at least 0.3 wt. % of the aldehyde, at least 0.5 wt. % of the aldehyde, or at least 1 wt. % of the aldehyde based on the liquid weight of the feed solution. The feed solution may contain at most 15 wt. % of the aldehyde, at most 12 wt. % of the aldehyde, at most 10 wt. % of the aldehyde, or at most 8 wt. % of the aldehyde based on the liquid weight of the feed solution. The feed solution may contain from 0.1 wt. % to 15 wt. % of the aldehyde, from 0.2 wt. % to 10 wt. % of the aldehyde, or from 0.3 wt. % to 8 wt. % of the aldehyde based on the liquid weight of the solution. If the aldehyde is present in the feed solution in an amount greater than 15 wt. %, or greater than the desired amount within the ranges set forth above, the feed solution may be diluted with solvent to obtain the desired concentration of aldehyde. For example, if the aldehyde is HPA in an aqueous solution at a concentration of greater than 15 wt. %, the aqueous solution may be diluted to the desired concentration by the addition of an aqueous liquid, e.g. water or aqueous PDO. It may be desirable to dilute the feed solution to reduce the concentration of the aldehyde in order to reduce the likelihood of formation of undesirable byproducts. In an embodiment, the feed is a solution comprising the aldehyde, where the feed may comprise the product of an oxirane hydroformylation reaction or an aqueous extract of the product of an oxirane hydroformylation reaction. The oxirane hydroformylation reaction product may be formed by reacting an oxirane with syngas in a solvent in the presence of a hydroformylation catalyst, for example a cobalt or a rhodium based hydroformylation catalyst. The oxirane may be, for example, ethylene oxide. The solvent may be, for example, an alcohol or an ether of the formula R2—O—R1 in which R1 is hydrogen or a C1-20 linear, branched, cyclic, or aromatic hydrocarbyl or a mono- or polyalkylene oxide. Preferred hydroformylation solvents include, for example, methyl-t-butyl ether, ethyl-t-butyl ether, diethyl ether, phenylisobutyl ether, ethoxyethyl ether, diphenyl ether, phenylisobutyl ether, ethoxyethyl ether, and diisopropyl ether. Blends of solvents such as tetrahydrofuran/toluene, tetrahydrofuran/heptane, and t-butylalcohol/hexane may also be used as the hydroformylation solvent. The syngas (i.e. synthesis gas) may comprise a mixture of H2 and carbon monoxide having an H2:CO ratio of at least 0.5:1 or at least 1:1 and at most 10:1 or at most 5:1. The syngas may be obtained from a commercially available source, or may be derived, for example, from a conventional water-gas shift reaction process. In an embodiment, the feed may be an aqueous extract of an oxirane hydroformylation reaction mixture that contains the aldehyde. The aqueous extractant used to extract the oxirane hydroformylation reaction mixture may be water, and an optional miscibilizing agent. In an embodiment, the amount of water used to extract the oxirane hydroformylation reaction mixture may generally be an amount sufficient to provide a water: reaction mixture volume ratio of from 1:1 to 1:20, or from 1:5 to 1:15. In an embodiment, the aqueous extraction may be carried out at a temperature of from 25° C. to 55° C. In an embodiment, the aqueous extraction may be carried out under 0.34 MPa (50 psig) to 1.37 MPa (200 psig) carbon monoxide partial pressure to maximize retention of hydroformylation catalyst in the hydroformylation reaction mixture and minimize extraction of the hydroformylation catalyst into the aqueous extractant. In an embodiment, the aqueous extractant comprising the feed containing the aldehyde may include some metal of the hydroformylation catalyst, which may be, for example, a water soluble species of cobalt or rhodium. The aqueous extract containing an aldehyde and hydroformylation catalyst may be used as the feed for the hydrogenation without removing the hydroformylation catalyst metal species. Alternatively, in another embodiment, the hydroformylation catalyst may be oxidized and removed from the feed, either a hydroformylation reaction mixture or an aqueous extract of a hydroformylation mixture, prior to hydrogenating the aldehyde in the feed. The hydroformylation catalyst may be oxidized, for example, by passing an oxidizing gas, e.g. air or oxygen, through the feed to oxidize the metal of the hydroformylation catalyst. The oxidized metal may be removed from the feed, for example, by contacting the feed with an acid ion exchange resin. The acid ion exchange resin may be a strong acid ion exchange resin or a weak acid ion exchange resin. In an embodiment, carbon monoxide may be stripped from the hydroformylation reaction mixture or aqueous extract of the hydroformylation reaction mixture containing the aldehyde prior to using either as a feed for hydrogenating the aldehyde. Carbon monoxide may poison the hydrogenation catalyst during hydrogenation, and is preferably removed from the feed containing the aldehyde prior to contact with the hydrogenation catalyst. Carbon monoxide may be removed from the hydroformylation reaction mixture or the aqueous extract of the hydroformylation reaction mixture by adjusting the pressure on the reaction mixture or aqueous extract to near atmospheric pressure and passing a stripping gas through the reaction mixture or aqueous extract to remove carbon monoxide from the reaction mixture or aqueous extract. The stripping gas may be air, oxygen, nitrogen, and/or a light hydrocarbon such as methane or natural gas. Most preferably, the feed may be an aqueous extract of an ethylene oxide hydroformylation reaction mixture, where the feed comprises HPA. The ethylene oxide hydroformylation reaction mixture may be formed by hydroformylating ethylene oxide with syngas in a methyl-t-butyl ether solvent in the presence of a cobalt carbonyl or rhodium carbonyl catalyst to produce HPA. The feed may be produced by extracting the ethylene oxide hydroformylation reaction mixture with water or an aqueous solution. In an embodiment the hydroformylation reaction mixture may be extracted with water or an aqueous solution under a carbon monoxide pressure of from 0.34 MPa (50 psig) to 1.37 MPa (200 psig) to minimize extraction of the hydroformylation catalyst into the aqueous extractant that forms the feed. In an embodiment, the aqueous extract feed containing the HPA may be stripped of carbon monoxide by depressurizing the aqueous extract and passing a stripping gas through the aqueous extract, where the stripping gas may be a light hydrocarbon, oxygen, air, and/or nitrogen. In an embodiment, residual hydroformylation catalyst may be removed from the aqueous extract feed containing the HPA by passing an oxidizing gas such as air or oxygen through the aqueous extract to oxidize the residual hydroformylation catalyst, then passing the aqueous extract through an acid ion exchange resin. The aldehyde in the feed is reacted with hydrogen in the presence of the catalyst using methods known in the art. A fixed-bed hydrogenation reactor is preferred for conducting the hydrogenation on an industrial scale with the catalyst used in the process of the invention. In such a reactor, the liquid reaction mixture flows or trickles over the catalyst in a fixed-bed together in the presence of hydrogen. To ensure good distribution of the hydrogen in the reaction mixture and uniform distribution of the gas/liquid mixture over the entire cross-section of the fixed bed, the liquid reaction mixture and hydrogen may be passed together through static mixers before being passed through the catalyst bed. In the process of the present invention, hydrogen is provided for contact with the aldehyde and the hydrogenation catalyst to hydrogenate the aldehyde in the feed. In an embodiment, hydrogen may be provided in an amount in excess of the amount necessary to convert all of the aldehyde in the feed. In an embodiment, hydrogen is provided at a hydrogen partial pressure of at least 1 MPa, or at least 2 MPa, or at least 4 MPa, or at least 5 MPa. In an embodiment, hydrogen is provided at a hydrogen partial pressure of at most 70 MPa, or at most 20 MPa, or at most 10 MPa. In an embodiment, hydrogen is provided at a hydrogen partial pressure of from IMPa to 70 MPa, or from 2MPa to 20 MPa, or from 4 MPa to 10 MPa. The feed comprising an aldehyde may be contacted with hydrogen and the hydrogenation catalyst to hydrogenate the aldehyde in the feed at a pH effective to selectively promote hydrogenation of the aldehyde. The feed containing the aldehyde may have a pH, or may be adjusted to a pH, at which the aldehyde may be inhibited from converting to undesirable byproducts, for example, acetals. The initial feed solution containing the aldehyde may also have a pH, or may be adjusted to a pH, at which the aldehyde may be efficiently converted in the hydrogenation reaction. Preferably the initial feed solution containing the aldehyde may have a pH, or may be adjusted to a pH, at which the aldehyde may be efficiently converted in a hydrogenation reaction and at which the aldehyde may be inhibited from converting to undesirable byproducts. In one embodiment, the aldehyde may be contacted with hydrogen and the hydrogenation catalyst at a pH of at least 2.0, at least 3.0, or at least 4.0 to hydrogenate the aldehyde. In one embodiment, the aldehyde may be contacted with hydrogen and the hydrogenation catalyst at a pH of at most 7.0, at most 6.5, at most 6.0, or at most 5.5 to hydrogenate the aldehyde. In one embodiment, the aldehyde may be contacted with hydrogen and the hydrogenation catalyst at a pH of from 2.0 to 7.0, from 3.0 to 6.5, from 4.0 to 6.0, or from 4.0 to 5.5 to hydrogenate the aldehyde. In an embodiment, the pH of the hydrogenation reaction mixture changes little during the reaction, and selecting or adjusting the pH of the initial feed comprising the aldehyde is effective to determine the pH at which the aldehyde is contacted with hydrogen and the hydrogenation catalyst during the course of the hydrogenation reaction. The temperature of the mixture of hydrogen, hydrogenation catalyst, and the feed containing the aldehyde (the “reaction mixture”) may be controlled within a desired range to hydrogenate the aldehyde. In an embodiment of the present invention, the reaction mixture is treated at a temperature of at least 40° C., at least 50° C. or at least 60° C. and a temperature of at most 190° C., at most 180° C., or at most 170° C. to hydrogenate the reaction mixture. In an embodiment of the invention the reaction mixture is treated at a temperature of from 40° C. to 190° C., or a temperature of from 50° C. to 180° C., or a temperature of from 60° C. to 170° C. to hydrogenate the reaction mixture. In an embodiment of the invention, the hydrogenation is conducted in two or more hydrogenation stages where a first hydrogenation stage has a first temperature, and each subsequent hydrogenation stage has a respective temperature that is higher than the preceding hydrogenation stage. The hydrogenation stages may occur in and be located in separate hydrogenation reactors, separate hydrogenation zones in a single hydrogenation reactor, or a single hydrogenation zone in a hydrogenation reactor where the temperature in the single hydrogenation zone is raised in accordance with a predetermined sequence while retaining the reaction mixture within the single hydrogenation zone. In one embodiment the reaction mixture containing the aldehyde, hydrogen and the hydrogenation catalyst is hydrogenated in a first hydrogenation stage having a temperature of from 40° C. to 90° C., alternatively from 50° C. to 85° C., until at least 40% at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 85%, or at least 95% of the aldehyde is converted. Subsequent to the first hydrogenation stage, the reaction mixture may be hydrogenated in a second hydrogenation stage having a temperature of from 50° C. to 120° C., alternatively from 60° C. to 110° C, where the temperature of the second hydrogenation stage is higher than the temperature of the first hydrogenation stage. The reaction mixture may be hydrogenated in the second stage until at least 70%, or at least 80%, or at least 90%, or at least 95%, or at least 99.5% of the aldehyde is converted. Such a stepped temperature hydrogenation is believed to inhibit the production of byproducts such as acetals by limiting the temperature of the hydrogenation reaction when high concentrations of the aldehyde are present. In an embodiment of the invention, the reaction mixture may be hydrogenated in a third hydrogenation stage having a temperature of from 120° C. to 190° C., alternatively from 130° C. to 180° C., subsequent to hydrogenation of the reaction mixture in the second hydrogenation stage where the temperature of the third hydrogenation stage is higher than the temperature of the second hydrogenation stage. Hydrogenation of the reaction mixture in the third hydrogenation stage may be effective to convert at least 98% or at least 99% or at least 99.9% of the aldehyde and also may be effective to revert byproduct acetals to desired product. For example, when the aldehyde in the reaction mixture is 3-hydroxypropionaldehyde, the acetal formed by combination of 3-hydroxypropionaldehyde and its hydrogenation product 1,3-propanediol may be reverted to 1,3-propanediol and 3-hydroxypropionaldehyde, and the 3-hydroxypropionaldehyde may then be hydrogenated to 1,3-propanediol. In another embodiment of the invention, the nickel-molybdenum α-alumina supported catalyst, as described herein, may be used as a catalyst to convert acetals to an alcohol containing material such as an alcohol, diol, triol, or polyol product by contacting the acetal with the catalyst in the presence of hydrogen. An acetal may be converted to an alcohol containing material by first being converted to an aldehyde and an alcohol under hydrogenation conditions, and second, contacting the resulting aldehyde with the catalyst in the presence of hydrogen to form an alcohol, where the alcohol containing material may contain the alcohol derived from the conversion of the acetal to an aldehyde and an alcohol and the alcohol derived from hydrogenation of the resulting aldehyde. In an embodiment the nickel-molybdenum α-alumina supported catalyst may be used in a second or subsequent hydrogenation stage to revert acetals in a hydrogenation reaction product derived from one or more prior hydrogenation stages in which a different conventional hydrogenation catalyst is used to hydrogenate an aldehyde to the alcohol, diol, triol, or polyol product. For example, a conventional hydrogenation catalyst such as a Raney nickel catalyst or a supported catalyst utilizing Pt and/or Ru as active metals on a support such as carbon, Al2O3, SiO2 or TiO2 may be utilized to hydrogenate a reaction mixture containing an aldehyde in a first hydrogenation stage at temperatures up to 120° C., and the nickel-molybdenum α-alumina supported catalyst may be used to hydrogenate the reaction mixture from the first hydrogenation stage in a second hydrogenation stage at temperatures of from 120° C. to 190° C. to revert acetals and convert remaining aldehyde to product. The hydrogenation catalyst used in the process of the present invention comprises a support and non-support metal components dispersed on the surface of the support. The support comprises at least 95 wt. %, at least 96 wt. %, at least 97 wt. %, at least 98 wt. %, at least 99 wt. %, or at least 99.5 wt. % α-alumina as measured by powder x-ray diffraction, and may contain at most 99.9 wt. % α-alumina phase as measured by powder x-ray diffraction. The support may contain up to 0.6 wt. % silica as measured by x-ray fluorescence. The support of the catalyst may contain little or no other phases of alumina other than α-alumina such as gamma-alumina, eta-alumina, delta-alumina, theta-alumina, or kappa-alumina. Other forms of alumina have substantially more porosity than α-alumina, and do not provide the desired mechanical strength or chemical resistance. In a preferred embodiment, the support of the catalyst contains no other forms of alumina as measured by powder X-ray diffraction than α-alumina. In a preferred embodiment, the support of the hydrogenation catalyst consists essentially of alumina in the α-alumina phase. The support of the catalyst has a high degree of mechanical strength and a small surface area/pore volume relative to supports utilized in conventional supported hydrogenation catalysts. The support may have few or no pores less than 500 Å in diameter, and a median pore diameter of from about 1400 Å to around 1800 Å, as measured by mercury porosimetry at a 140° contact angle. The support preferably may have a pore volume of from 0.30 ml/g to 0.50 ml/g. As used herein, pore size distribution (including median pore diameter determinations) and pore volume are defined as measured by mercury porosimetry at a 140° contact angle, an Hg surface tension of 485 dyne/cm, over a pressure range of from 14.37 to 59774 psia (0.099 to 412 MPa). Mercury porosimetry measurements may be made with an Autopore IV 9500 availiable from Micromeritics Instrument Corp. As a result of its limited porosity, the support may have an N2 BET surface area of less than 10 m2/g, and preferably has an N2 BET surface area of from 3 m2/g to 9 m2/g, and more preferably has a N2 BET surface area of from 4 m2/g to 7 m2/g. As used herein, N2 BET surface area refers to the surface area of a solid measured by the Brunauer, Emmett, and Teller method of calculation of the surface area of a solid by physical adsorption of nitrogen gas molecules, which is well known in the art. Generally, decreasing support surface area increases the mechanical strength of the support while decreasing the available area upon which to deposit the active metal components of the catalyst. The lack of small pores provides the support with a relatively high crush strength and inhibits breakdown of the catalyst into fines over the life of the catalyst. The high crush strength of the support provides the catalyst with the strength necessary for a long catalyst life as a fixed-bed hydrogenation catalyst. The support of the hydrogenation catalyst may have a shape, size, and structure such that the support can be placed and retained in a fixed hydrogenation bed such as a trickle bed reactor. Most preferably the support is a tri-lobal or cylindrical pellet. The non-support active metal components of the hydrogenation catalyst deposited on the surface of the support comprise nickel and/or one or more compounds thereof and molybdenum and/or one or more compounds thereof. The nickel and/or compound(s) thereof comprises from 3 wt. % to 9 wt. % of the weight of the catalyst, by metallic weight, or from 4 wt. % to 7 wt. % of the weight of the catalyst, by metallic weight. The molybdenum and/or compound(s) thereof comprises from 1 wt. % to 4 wt. % of the weight of the catalyst, by metallic weight, or from 2 wt. % to 3 wt. % of the weight of the catalyst, by metallic weight. The nickel and/or compound(s) thereof is preferably present in the catalyst in a weight ratio by metallic weight of at least 1:1 relative to the molybdenum and/or compound(s) thereof. In an embodiment, the nickel and/or compound(s) thereof is present in the catalyst in a weight ratio by metallic weight of from 1:1 to 3:1 relative to the molybdenum and/or compound(s) thereof. In an embodiment, small amounts of catalytically active metal components other than nickel and molybdenum and/or their compounds may be present in the catalyst on the surface of the support as non-support metal components, and may comprise up to 1 wt. % of the catalyst, by metallic weight. In an embodiment, cobalt and/or one or more compounds thereof comprise(s) from 0.1 wt. % to 1 wt. % of the catalyst, by metallic weight. Preferably, due to the expense of noble metals, the non-support active metal components do not include the noble metals ruthenium, platinum, and palladium (i.e. ruthenium, platinum, and palladium are excluded from non-support metal components that may be utilized in the catalyst). Preferably, the non-support active metal components of the hydrogenation catalyst consist essentially of nickel and/or one or more compounds of thereof and molybdenum and/or one or more compounds thereof. The nickel, as metallic nickel and/or one or more compounds of nickel, preferably comprises from 3 wt. % to 6 wt. % of the weight of the hydrogenation catalyst, by metallic weight. The molybdenum, as metallic molybdenum and/or one or more compounds of molybdenum, preferably comprises from 1 wt. % to 3 wt. % of the hydrogenation catalyst, by metallic weight. The non-support active metal components may substantially increase the surface area of the finished hydrogenation catalyst relative to the surface area of the support, thereby providing more surface area than the support alone to catalytically interact to convert aldehydes in the presence of hydrogen. The surface area of the finished catalyst may be from 1.5 to 5 times the surface area of the support, or may be from 1.5 to 3 times the surface area of the support. The finished catalyst may have an N2 BET surface area of from 10 m2/g to 30 m2/g, or from 15 m2/g to 25 m2/g. The non-support active metal components may decrease the pore volume of the finished catalyst relative to the pore volume of the support. Typically the pore volume (Hg) of the finished catalyst may range from 0.2 cc/g to 0.35 cc/g , measured by mercury porosimetry at a 140° contact angle. The median pore diameter of the finished catalyst may range from 1300 Å to 1700 Å. As noted above, the relatively high crush strength of the support provides the hydrogenation catalyst with strength that may inhibit the breakdown of the catalyst into fines, thereby enhancing the lifespan of the catalyst. The crush strength of the catalyst may be measured by a flat plate crush of individual catalyst pellets, and reported as the average force required to crush the pellet when placed length-wise between two flat plates per average length of the catalyst pellet. The flat plate crush strength is calculated according to the following formula: Side Crush Strength per Length = Σ ( All Individual Crush Strength Measurements ) Σ ( All Individual Length Measurements ) The hydrogenation catalyst used in the process of the present invention has a high crush strength. The catalyst, when having a length of from 2 mm to 6 mm and a diameter of from 0.8 mm to 1.6 mm, may have an initial crush strength, prior to being exposed to hydrogenation conditions, of at least 2.7 kg/mm, more preferably at least 2.8 kg/mm, more preferably at least 2.9 kg/mm, and more preferably at least 3.0 kg/mm. The hydrogenation catalyst used in the process of the present invention also preferably retains its crush strength after exposure to hydrogenation conditions, where spent hydrogenation catalyst, initially having the dimensions described above, preferably has a crush strength of at least 2.3 kg/mm, more preferably at least 2.4 kg/mm, and most preferably at least 2.5 kg/mm. The hydrogenation catalyst has substantial catalytic activity to convert the aldehyde under hydrogenation conditions, especially after an extended period of time. The catalyst may have an initial activity sufficient to catalyze hydrogenation of an aldehyde at a rate of at least 50 ml aldehyde/ml catalyst.hr at a temperature of from 50° C. to 90° C., a pH of from 4.5 to 6.0, and a hydrogen partial pressure of from 6.89 MPa to 10.68 MPa. In an embodiment of the invention, the catalyst has an activity sufficient to catalyze hydrogenation of an aldehyde at a rate of at least 30 ml aldehyde/ml catalyst.hr at a temperature of from 50° C. to 90° C., a pH of from 4.5 to 6.0, and a hydrogen partial pressure of from 6.894 MPa to 10.68 MPa after at least 24 hours exposure to the same hydrogenation conditions. In another embodiment of the invention, the catalyst has an activity sufficient to catalyze hydrogenation of an aldehyde at a rate of at least 35 ml aldehyde/ml catalyst.hr at a temperature of from 50° C. to 90° C., a pH of from 4.5 to 6.0, and a hydrogen partial pressure of from 6.89 MPa to 10.68 MPa after at least 24 hours of exposure to the same hydrogenation conditions, and preferably has an activity to catalyze hydrogenation of an aldehyde at a rate of at least 40 ml aldehyde/ml catalyst.hr under such conditions after at least 24 hours of exposure to the same hydrogenation conditions. In an embodiment of the invention, the hydrogenation catalyst used in the process of the present invention contains no halogens. Halogens may be deposited on the support of the catalyst in the preparation of the catalyst as a metal salt with the active metal components of the catalyst. Halogens, however, are known to corrode metal components of hydrogenation reactors, so it is desirable to avoid catalysts containing halogens. If metal salts are used to prepare the catalyst of the present invention, preferably the catalyst is prepared using metal salts of the active metals that are not halide salts. The hydrogenation catalyst used in the process of the present invention may be prepared by first preparing the support comprised of α-alumina; then depositing the non-support metal components on the support, where the non-support metal components include nickel and/or one or more compounds thereof, and molybdenum and/or one or more compounds thereof; calcining the support with the non-support metal components thereon to form a catalyst precursor; and reducing the metal of the non-support metal components of the catalyst precursor to form the catalyst. The α-alumina support may be prepared by calcining extruded alumina pellets. The extruded alumina pellets may be produced by mulling a mixture of pseudo-boehmite precipitated alumina powder with water and acid to form an extrudable mixture. The extrudable mixture may then be extruded through shaped dies to form the pellets, which may then be dried. The extruded pellets may then be dried and then calcined at a temperature of at least 1150° C., preferably from 1250° C. to 1350° C., for at least 1 hour to form the α-alumina phase support. The calcination reduces the pore volume (H2O) of the alumina pellets from above 0.8 cc/g to 0.3-0.5 cc/g, and reduces the N2 BET surface area of the pellets from above 225 m2/g to below 10 m2/g while increasing the median pore diameter of the pellets from about 100 Å to about 1400-1800 Å. Preferably the calcined α-alumina pellets used as the support have a tri-lobe or cylindrical shape. The nickel component is deposited on the support comprised of α-alumina. The nickel component should be dispersed relatively evenly over the surface of the support to ensure that the catalyst has high activity. The nickel component may be deposited on the support by any procedure that deposits a disperse desired quantity of metallic nickel onto the support. The nickel component is preferably deposited on the support by determining the water absorption capacity of the support, and loading the support in accordance with its water absorption capacity with an aqueous nickel solution that has a nickel content corresponding to the desired metallic nickel concentration in the finished catalyst—where the entire quantity of the solution is absorbed by the support. The nickel solution may be prepared to provide a concentration of nickel, by metallic weight, of 3 wt. % to 9 wt. % of the finished catalyst, or from 4 wt % to 7 wt. % of the finished catalyst by metallic weight. In an embodiment of the invention, the nickel solution is prepared to provide a concentration of nickel, by metallic weight, of 5 wt. % of the finished catalyst. Preferably, nickel carbonate is used in the aqueous nickel solution, although other water-soluble nickel compounds such as nickel nitrate or nickel acetate may be used either with nickel carbonate or in place of nickel carbonate in the aqueous nickel solution. Nickel halide salts may be used in the aqueous nickel solution, but are less preferred, since halides are known to be corrosive to steel components of hydrogenation reactors. Ammonium carbonate [(NH4)2CO3] and ammonium hydroxide may be included in the aqueous nickel solution to aid in the dissolution of the nickel and/or nickel compound(s) in the aqueous solution. The molybdenum component may also be deposited on the support with the nickel as a mixture or alloy of nickel and molybdenum. The molybdenum component may be included in a weight ratio relative to the nickel component, by metallic weight, of from 1:1 to 1:3. Preferably, the desired amount of molybdenum component is included in an aqueous base/water-soluble form in the aqueous nickel solution, which is then loaded onto the support. Molybdenum trioxide may be used in an aqueous nickel/molybdenum solution, although other aqueous base/water soluble molybdenum compounds may be used such as ammonium dimolybdate and ammonium heptamolybdate tetrahydrate. If desired additional metal components, for example cobalt or one or more cobalt compounds, may be deposited on the support with the nickel and molybdenum. The additional metal components may be included in an amount effective to produce a catalyst containing up to 1 wt. % of the additional metal components. If cobalt is used, the desired amount of cobalt may be included in an aqueous base/water soluble form in the aqueous nickel and molybdenum solution, which is then loaded onto the support. Cobalt may be included in the aqueous nickel/molybdenum solution as cobalt carbonate. After the support is impregnated with the nickel and molybdenum components, and other additional metal components if desired, the metal impregnated support may be aged. Preferably the metal impregnated support is aged at room temperature for a period of from 1 hour to 3 hours, most preferably for a period of 2 hours. The metal impregenated support may then be dried and calcined to form a catalyst precursor. The metal impregnated support may be dried at a temperature of from 25° C. to 250° C. for a period of from 1 hour to 4 hours, and most preferably at a temperature of 150° C. for a period of 3 hours. After the metal impregnated support is dry, it may be calcined at a temperature of from 350° C. to 500° C. for a period of from 30 minutes to 2 hours, and most preferably at a temperature of 483° C. for a period of 1 hour. The catalyst precursor may then be activated to form the catalyst by reducing the metals of the non-support metal components to their metallic, zero-oxidation states. The catalyst precursor may be reduced to form the catalyst by holding the catalyst precursor under a hydrogen atmosphere at an elevated temperature. In an embodiment, the catalyst precursor may be held at a temperature of from 100° C. to 500° C. for a period of from 20 minutes to 24 hours to reduce the metals of the non-support metal components and activate the catalyst. The catalyst is preferably activated by heating the catalyst precursor under a flowing H2 atmosphere. Most preferably, the catalyst is activated under flowing H2 atmosphere by heating at a temperature ramped up from room temperature to 107° C. at 0.4° C. per minute, holding the catalyst precursor at 107° C. for 1 hour, ramping the temperature up from 107° C. to 399° C. at 0.9° C. per minute, holding the catalyst precursor at 399° C. for 4 hours, and cooling to room temperature. The activated catalyst may be transferred to storage under an inert atmosphere and stored under liquid PDO or ethylene glycol prior to use. In a preferred process of the present invention, HPA is the aldehyde to be hydrogenated, and is hydrogenated to form PDO. PDO may be prepared by hydrogenating an aqueous solution of HPA in the presence of the catalyst in accordance with the process of the present invention. An aqueous solution of HPA may be prepared by a process involving the catalyzed hydroformylation (reaction with synthesis gas, H2/CO) of ethylene oxide to form a dilute mixture of HPA in an organic solvent, typically methyl t-butyl ether (MTBE). The HPA in the organic solvent can be extracted into water to form a more concentrated HPA solution. U.S. Pat. No. 5,786,524 describes such a process wherein ethylene oxide and synthesis gas are contacted at 50° C. to 100° C. and at 3.44 MPa to 34.4 MPa in the presence of a cobalt or rhodium hydroformylation catalyst and a catalyst promoter to produce a product mixture containing HPA. Water is added to the HPA mixture and most of the HPA is extracted into the water to provide an aqueous phase comprising a higher concentration of HPA and an organic phase containing at least a portion of the hydroformylation catalyst. Alternatively, an aqueous solution of HPA may be prepared by hydration of acrolein, as described in detail in U.S. Pat. No. 5,015,789. In that process, acrolein and water are reacted in a weight ratio of 1:2 to 1:20, preferably from 1:3 to 1:6, at 30° C. to 120° C., preferably at 50° C. to 90° C., and a pressure in a range from 0.1 MPa to 2.0 MPa, preferably 0.2 MPa to 0.5 MPa, in the presence of an acidic cation exchanger resin to form HPA. After production of HPA, the HPA solution is separated from the ion exchanger, preferably by sedimentation or filtration, and the reaction mixture is separated from unreacted acrolein to provide a concentrated aqueous solution of HPA. The separation of acrolein may be carried out by distillation under reduced pressure, preferably in a thin-layer evaporator. However obtained, the aqueous solution of HPA may be supplied to at least one hydrogenation reactor containing the hydrogenation catalyst described above, preferably in a fixed-bed configuration, for hydrogenation to PDO. The preferred hydrogenation catalyst may contain from 3 wt. % to 7 wt. % nickel and from 2 wt. % to 3 wt. % molybdenum, by metallic weight, on a support containing at least 95 wt. % α-alumina. The catalyst may be formed in the shape of tri-lobal or cylindrical pellets. The aqueous solution of HPA may contain HPA in a concentration in the range of 0.2 wt. % to 50 wt. %, based on the weight of the aqueous liquid, which is usually water or a combination of water and PDO. It is desirable to use a dilute solution of HPA with a fixed-bed catalyst, preferably having an HPA concentration of at most 15 wt. % HPA, more preferably having an HPA concentration of from 0.2 wt. % to 15 wt. %, and most preferably having an HPA concentration of at most 8 wt. %, particularly an HPA concentration of from 0.5 wt. % to 8 wt. %. Diffusion of H2 through the fixed-bed catalyst is the rate limiting step in hydrogenating HPA to PDO, and the selectivity of hydrogenation of HPA to PDO is increased by utilizing an aqueous solution having a dilute concentration of HPA to ensure that HPA is catalyzed in the presence of H2 to form PDO, rather than catalyzed to form undesirable side products in the absence of H2. Although any aqueous liquid that will not interfere with hydrogenation of HPA, including water, may be used to dilute the aqueous solution of HPA to the desired concentration, it is preferred to employ an aqueous PDO containing solution such as a portion of the product stream from the hydrogenation step. Dilution with such a PDO-containing solution serves to concentrate PDO in the system water, thus avoiding the high cost and recovery of dilute PDO from water which would result from the use of water alone as diluent. The HPA in the dilute aqueous HPA solution may be reacted with hydrogen in the presence of the catalyst using methods known in the art. A fixed-bed hydrogenation reactor is preferred for conducting the hydrogenation on an industrial scale with the catalyst of the invention. In such a reactor, the liquid reaction mixture flows or trickles over the catalyst in a fixed-bed together with the hydrogen. To ensure good distribution of the hydrogen in the reaction mixture and uniform distribution of the gas/liquid mixture over the entire cross-section of the fixed bed, the liquid reaction mixture and hydrogen may be passed together through static mixers before the catalyst bed. The hydrogenation process may be carried out in one stage or in two or more sequential stages. Generally, the hydrogenation may be carried out at a temperature of from 30° C. to 190° C. and at a hydrogen partial pressure of from 3.44 MPa to 68.9 MPa. In a preferred embodiment, hydrogenation is initially carried out at a temperature of from 40° C. to 90° C. and a hydrogen partial pressure of from 8.96 MPa to 10.3 MPa, followed by a second stage hydrogenation carried out at a temperature higher than that of the first stage and within the range of from 50° C. to 120° C. and a hydrogen partial pressure of from 7.56 MPa to 10.3 MPa, and then optionally in a third stage hydrogenation at a temperature greater than the temperature of the second stage and with a temperature of 120° C. or greater, preferably from 120° C. to 190° C. and a hydrogen partial pressure of from 6.89 MPa to 10.3 MPa. The second hydrogenation stage and any subsequent hydrogenation stages may be carried out at higher temperatures without negatively affecting selectivity since most of the HPA is hydrogenated in the first stage, and the solution has a very dilute concentration of HPA in the second and later hydrogenation stages. In this preferred process, the hydrogenation is optionally carried out in two or more separate hydrogenation vessels. The hydrogenation reaction is preferably carried out at acidic conditions below pH 6.5 since HPA tends to form aldol condensation products and heavy end byproducts at higher pHs. Preferably the hydrogenation is carried out at a pH of from 4.0 to 6.5. The hydrogenation reaction may be carried out in a batch process or in a continuous process. For industrial scale production of PDO from HPA it is preferred to utilize a continuous process. The process of hydrogenating HPA to PDO of the present invention with the catalyst of the present invention provides a high degree and rate of conversion of HPA by hydrogenation, particularly over an extended period of time. HPA may be initially converted in the hydrogenation reaction at a rate of at least 50 ml HPA/ml catalyst.hr at a temperature of from 40° C. to 90° C., a pH of from 4.0 to 6.5, and a hydrogen partial pressure of from 6.89 MPa to 11.0 MPa. HPA may still be hydrogenated in the hydrogenation reaction with a high degree of activity after the catalyst is exposed to hydrogenation reaction conditions for an extended period of time. In an embodiment of the invention, HPA is hydrogenated at a rate of at least 30 ml HPA/ml catalyst.hr at a temperature of from 40° C. to 90° C., a pH of from 4.0 to 6.5, and a hydrogen partial pressure of from 6.89 MPa to 11.0 MPa after at least 24 hours exposure to HPA hydrogenation conditions. In another embodiment, HPA is hydrogenated at a rate of at least 35 ml HPA/ml catalyst.hr at a temperature of from 40° C. to 90° C., a pH of from 4.0 to 6.5, and a hydrogen partial pressure of from 6.89 MPa to 11.0 MPa after at least 24 hours of exposure to HPA hydrogenation conditions, and most preferably HPA is hydrogenated at a rate of at least 40 ml HPA/ml catalsyt.hr under such conditions after at least 24 hours of exposure to HPA hydrogenation conditions. EXAMPLE 1 HPA was converted to PDO in accordance with the present invention using a catalyst comprising an α-alumina support with 5 wt. % nickel and 2 wt. % molybdenum deposited thereon, where the α-alumina support was comprised of at least 95% α-alumina. The catalyst was prepared as follows. Gamma-alumina pellets were calcined at 1275° C. to prepare the α-alumina support. An aqueous nickel and molybdenum solution was prepared by dissolving 7.1 grams of ammonium carbonate in 20 ml of ammonium hydroxide solution (28-30%) with moderate heat and stirring, followed by the addition and dissolution of 3.9 grams of ammonium dimolybdate in the ammonium carbonate/ammonium hydroxide solution, after which 13.71 grams of nickel carbonate was added and dissolved in the ammonium carbonate/ammonium hydroxide/ammonium dimolybdate solution. The solution volume was brought to 40 ml with additional ammonium hydroxide solution (28-30%). 100 grams of the α-alumina support was impregnated with the solution containing the nickel and molybdenum, absorbing 100% of the solution volume. The nickel/molybdenum solution impregnated support was then aged for 1 hour at room temperature. The nickel/molybdenum impregnated support was then dried at 150° C. for 3 hours, and then calcined at 453° C. for 1 hour in air to produce a catalyst containing 5 wt. % nickel and 2 wt. % molybdenum. Prior to use the catalyst was reduced under a flow of hydrogen gas. 50 grams of the catalyst was heated under a flow of hydrogen gas from room temperature to 107° C. at 0.4° C./minute and then held at 107° C. for 1 hour, after which the temperature was ramped to 399° C. at 0.9° C./minute and the catalyst was held at 399° C. for 4 hours. The catalyst was then cooled to room temperature and dropped into 1,3-propanediol without air contact. The hydrogenation was conducted as follows. A 21 ml volume of the nickel/molybdenum catalyst, with a catalyst density of 0.62 g/cm3 and a void fraction of 0.42, was loaded into a batch hydrogenation wire basket to provide a catalyst charge of 13.1 grams, which was then topped with a ⅛ inch (0.32 cm) layer of inert denstone to prevent the catalyst from moving during the hydrogenation. The basket containing the catalyst was then secured in the cooling coils of a batch hydrogenation reactor. The catalyst was then rinsed three times with deionized nitrogen sparged water. The catalyst was then subjected to 20 batch hydrogenation cycles, each cycle lasting for 120 minutes. Importantly, the catalyst was not renewed or refreshed between batches, so each batch sequentially aged the catalyst. Initially the reactor was loaded with 300 ml of an aqueous HPA/PDO feed mixture containing 1% n-butanol internal standard by weight, and after each batch cycle the hydrogenation reactor was drained through a dip tube then reloaded with 300 ml of aqueous HPA/PDO feed mixture. The feed mixture of aqueous HPA/PDO for the 20 batch hydrogenation cycles in Example 1 was mixed as shown in Table 1 below. TABLE 1 Cycle 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 HPA 60 60 60 60 150 150 150 150 150 150 150 150 150 150 150 150 60 60 60 60 (ml) PDO/ 240 240 240 240 150 150 150 150 150 150 150 150 150 150 150 150 240 240 240 240 H2O (ml) Total 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 (ml) The HPA content of the HPA portion of the feed mixture was between 5 wt. % and 30 wt. % prior to dilution with the PDO/H2O solution. For each cycle, the loaded reactor was pressured with hydrogen to 2.07 MPa and then vented slowly three times to remove air from the system. The vented, loaded reactor was then pressured to a range of 5.5 MPa to 6.2 MPa with hydrogen. The temperature of the pressurized loaded reactor was then raised to 60° C. After the temperature of the reactor was stable at 60° C., the hydrogen pressure was increased to the final hydrogenation reaction pressure of 7.17 MPa. The hydrogenation reaction of each cycle was run for 120 minutes, and samples were taken of the reaction mixture at 0 minutes, 30 minutes, 60 minutes, and 120 minutes. The samples were analyzed by gas chromatograph for 3-hydroxypropionaldehyde and 1,3-propanediol in a solution of sample and tetrahydrofuran in a ratio, by volume, of sample to THF of 1:5. Kinetics were determined by the rate of disappearance of HPA. The initial HPA content, final HPA content, and amount of HPA converted by the catalyst are shown in Table 2. Table 2 also shows the HPA conversion rate initially and the average HPA conversion rate for cycles 13-15 (catalyst activity after 24 hours of exposure to hydrogenation conditions, for hours 24-30). Finally, Table 2 shows the initial PDO content and the final PDO content of each cycle. TABLE 2 HPA Average HPA Initial Final HPA conversion conversion rate cycles HPA HPA converted rate 13-15 Initial PDO Final PDO Cycle (wt. %) (wt. %) (g) (ml/ml · hr) (ml/ml · hr) (wt. %) (wt. %) 1 3.03 0.00 9.09 >50 — 19.5 23.8 2 2.63 0.00 7.90 >50 — 19.7 24.0 3 2.61 0.01 7.80 72.3 — 20.2 23.6 4 2.80 0.01 8.37 68.6 — 21.6 25.1 5 7.31 0.21 21.3 51.2 — 14.3 23.2 6 7.22 0.40 20.5 41.2 — 14.4 23.4 7 7.40 0.57 20.5 36.1 — 14.7 22.8 8 7.85 0.58 21.8 37.4 — 15.0 24.2 9 6.61 0.33 18.8 44.6 — 14.4 23.9 10 6.94 0.50 19.3 37.0 — 14.3 22.2 11 6.92 0.67 18.8 33.0 — 14.8 22.3 12 6.64 0.73 17.7 31.7 — 15.1 23.9 13 6.57 0.56 18.0 35.6 33.5 14.3 22.7 14 6.88 0.59 18.9 34.3 33.5 14.0 22.0 15 7.00 0.77 18.7 30.5 33.5 14.1 22.2 16 7.50 0.92 19.7 29.9 — 15.2 24.0 17 2.32 0.00 7.0 — — 20.0 24.0 18 2.33 0.00 7.0 — — 19.9 24.6 19 2.30 0.00 6.9 — — 20.2 23.5 20 2.76 0.00 8.29 — — 23.58 26.81 As shown in Table 2, the nickel/molybdenum catalyst is highly effective for converting HPA at a high activity rate over the entire set of batches. As shown by the initial PDO and final PDO measurements in Table 2, HPA was converted substantially into PDO. EXAMPLE 2 HPA was converted to PDO in accordance with the present invention using a catalyst comprising an α-alumina support with 5 wt. % nickel, 2 wt. % molybdenum, and 0.5 wt. % cobalt deposited thereon, where the α-alumina support was comprised of at least 95% α-alumina. The catalyst was prepared as follows. Gamma-alumina pellets were calcined at 1275° C. to prepare the α-alumina support. An aqueous nickel/molybdenum/cobalt solution was prepared by dissolving 3.6 grams of ammonium carbonate in 12 ml of ammonium hydroxide solution (28-30%) with moderate heat and stirring, followed by the addition and dissolution of 2.0 grams of ammonium dimolybdate in the ammonium carbonate/ammonium hydroxide solution, after which 6.9 grams of nickel carbonate was added and dissolved in the ammonium carbonate/ammonium hydroxide/ammonium dimolybdate solution, and then 0.6 grams of cobalt carbonate was added and dissolved therein. The solution volume was brought to 20 ml with additional ammonium hydroxide solution (28-30%). 50 grams of the α-alumina support was impregnated with the solution containing the nickel, molybdenum and cobalt, absorbing 100% of the solution volume. The nickel/molybdenum/cobalt solution impregnated support was then aged for 1 hour at room temperature. The nickel/molybdenum/cobalt impregnated support was then dried at 150° C. for 3 hours, and then calcined at 453° C. for 1 hour in air to produce a catalyst containing 5 wt. % nickel, 2 wt. % molybdenum, and 0.5 wt. % cobalt. Prior to use the catalyst was reduced under a flow of hydrogen gas as described above in Example 1. The hydrogenation was conducted in the same manner as set forth in Example 1 for 20 cycles. The initial HPA content, final HPA content, and amount of HPA converted by the catalyst are shown in Table 3. Table 3 also shows the HPA conversion rate initially and the average HPA conversion rate for cycles 13-15 (catalyst activity after 24 hours of exposure to hydrogenation conditions, for hours 24-30). Finally, Table 3 shows the initial PDO content and the final PDO content of each cycle. TABLE 3 HPA Average HPA Initial Final HPA conversion conversion rate cycles HPA HPA converted rate (ml/ 13-15 Initial PDO Final PDO Cycle (wt. %) (wt. %) (g) ml · hr) (ml/ml · hr) (wt. %) (wt. %) 1 3.85 0.00 11.6 >50 — 18.3 19.9 2 3.38 0.00 10.1 >50 — 15.9 18.8 3 3.40 0.00 10.2 >50 — 17.6 18.8 4 3.51 0.00 10.5 >50 — 18.1 19.9 5 8.80 0.89 23.7 32.1 — 13.9 19.5 6 9.00 1.35 23.0 25.8 — 14.0 19.5 7 9.17 1.78 22.2 22.2 — 14.2 19.9 8 9.48 2.03 22.4 20.8 — 14.6 19.9 9 9.11 1.93 21.6 21.4 — 14.0 18.4 10 9.01 2.34 20.0 17.8 — 13.9 17.8 11 9.33 2.43 20.7 18.0 — 13.7 18.2 12 9.79 2.42 22.1 18.3 — 14.3 18.4 13 9.92 2.50 22.3 18.0 16.8 14.3 19.6 14 9.84 2.76 21.2 16.6 16.8 14.4 19.2 15 9.87 2.91 20.9 15.9 16.8 14.2 18.3 16 10.15 3.08 21.2 16.2 — 14.6 18.9 17 3.90 0.21 11.1 — — 16.6 20.0 18 3.36 0.13 9.7 — — 17.9 18.5 19 3.41 0.09 10.0 — — 18.5 19.0 20 3.49 0.08 10.2 — — 18.0 18.8 As shown in Table 3, the nickel/molybdenum/cobalt catalyst is effective for converting HPA at a relatively high activity rate over the entire set of batches. As shown by the intial PDO and final PDO measurements in Table 3, HPA was converted substantially into PDO. EXAMPLE 3 For comparative purposes, HPA was converted to PDO with a catalyst comprising an α-alumina support with 5 wt. % nickel deposited thereon, a process not in accordance with the present invention, where the α-alumina support was comprised of at least 95% α-alumina. The catalyst was prepared as follows. Gamma-alumina pellets were calcined at 1275° C. to prepare the α-alumina support. An aqueous nickel solution was prepared by dissolving 6.9 grams of ammonium carbonate in 20 ml of ammonium hydroxide solution (28-30%) with moderate heat and stirring, followed by the addition and dissolution of 13.3 grams of nickel carbonate in the ammonium carbonate/ammonium hydroxide solution. The solution volume was brought to 40 ml with additional ammonium hydroxide solution (28-30%). 100 grams of the α-alumina support was impregnated with the nickel solution, absorbing 100% of the solution volume. The nickel solution impregnated support was then aged for 1 hour at room temperature. The nickel impregnated support was then dried at 150° C. for 3 hours, and then calcined at 453° C. for 1 hour in air to produce a catalyst containing 5 wt. % nickel. Prior to use the catalyst was reduced as set forth in Example 1. HPA was hydrogenated to PDO in accordance with the procedure set forth in Example 1 using the nickel catalyst rather than the nickel/molybdenum catalyst. A 21 ml volume of the catalyst (12.1 grams) was used with a catalyst density of 0.58 g/cm3 and a void fraction of 0.42 The initial HPA content, final HPA content, and amount of HPA converted by the catalyst are shown in Table 4. Table 4 also shows the HPA conversion rate initially and the average HPA conversion rate for cycles 13-15 (catalyst activity after 24 hours of exposure to hydrogenation conditions, for hours 24-30). Finally, Table 4 shows the initial PDO content and the final PDO content of each cycle. TABLE 4 HPA Average HPA Initial HPA conversion conversion rate cycles HPA Final HPA converted rate (ml/ 13-15 Initial PDO Final PDO Cycle (wt. %) (wt. %) (g) ml · hr) (ml/ml · hr) (wt. %) (wt. %) 1 3.53 0.00 10.58 >50 — 19.5 23.9 2 3.10 0.00 9.31 >50 — 20.4 23.7 3 3.09 0.65 7.32 20.59 — 20.9 23.3 4 3.21 1.21 6.00 12.98 — 21.5 23.63 5 8.33 6.48 5.56 3.61 — 15.9 17.7 6 9.52 7.62 5.71 2.77 — 15.4 16.4 7 9.67 8.09 4.74 2.15 — 15.2 15.4 8 10.47 8.97 4.50 2.56 — 16.0 16.2 9 9.48 8.58 2.69 1.49 — 15.5 15.9 10 9.36 8.57 2.37 0.89 — 14.6 14.7 11 9.38 8.76 1.88 1.33 — 14.2 14.7 12 10.12 9.63 1.48 0.53 — 15.3 15.7 13 9.49 9.01 1.44 1.00 2.1 14.6 14.9 14 9.66 7.86 5.40 3.03 2.1 14.5 12.7 15 9.66 8.21 4.33 2.33 2.1 14.5 13.4 16 10.52 10.11 1.22 0.16 — 15.8 15.6 17 4.58 4.24 0.99 0.74 — 19.6 19.4 18 3.71 3.56 0.44 0.51 — 19.7 20.5 19 3.70 3.35 1.06 1.10 — 20.8 20.3 20 3.79 3.78 0.04 0.54 21.1 22.7 As shown in Table 4, particularly in comparison with Tables 2 and 3, the 5 wt. % nickel catalyst was not as effective for converting HPA at a high activity rate over the entire set of batches as the catalyst used in Example 1 or Example 2. EXAMPLE 4 For comparative purposes, HPA was converted to PDO in accordance with a method not of the present invention using a catalyst comprising an α-alumina support with 5 wt. % nickel and 2 wt. % tungsten deposited thereon, where the α-alumina support was comprised of at least 95% α-alumina. The catalyst was prepared as follows. Gamma-alumina pellets were calcined at 1275° C. to prepare the α-alumina support. An aqueous nickel and tungsten solution was prepared by dissolving 7.1 grams of ammonium carbonate in 20 ml of ammonium hydroxide solution (28-30%) with moderate heat and stirring, followed by the addition and dissolution of 13.6 grams of nickel carbonate in the ammonium carbonate/ammonium hydroxide solution, after which 3.0 grams of ammonium meta tungstate was added and dissolved in the ammonium carbonate/ammonium hydroxide/nickel carbonate solution. The solution volume was brought to 40 ml with additional ammonium hydroxide solution (28-30%). 100 grams of the α-alumina support was impregnated with the solution containing the nickel and tungsten, absorbing 100% of the solution volume. The nickel/tungsten solution impregnated support was then aged for 1 hour at room temperature. The nickel/tungsten impregnated support was then dried at 150° C. for 3 hours, and then calcined at 453° C. for 1 hour in air to produce a catalyst containing 5 wt. % nickel and 2 wt. % tungsten. Prior to use the catalyst was reduced under a flow of hydrogen gas as described above in Example 1. The hydrogenation was conducted in the same manner for 20 cycles as set forth in Example 1, except the catalyst had a catalyst density of 0.57 g/cm3 and a void fraction of 0.42, and the 21 ml volume of catalyst provided a catalyst charge of 11.9 grams. The initial HPA content, final HPA content, and amount of HPA converted by the catalyst are shown in Table 5. Table 5 also shows the HPA conversion rate initially and the average HPA conversion rate for cycles 13-15 (catalyst activity after 24 hours of exposure to hydrogenation conditions, for hours 24-30). Finally, Table 5 shows the initial PDO content and the final PDO content of each cycle. TABLE 5 HPA Average HPA Initial Final HPA conversion conversion rate cycles HPA HPA converted rate 13-15 Initial PDO Final PDO Cycle (wt. %) (wt. %) (g) (ml/ml · hr) (ml/ml · hr) (wt. %) (wt. %) 1 3.26 0.00 9.8 >50 — 19.5 23.3 2 2.83 0.00 8.5 >50 — 19.2 21.8 3 3.09 0.17 8.8 39.9 — 21.1 23.3 4 3.13 0.38 8.3 28.1 — 21.8 23.3 5 7.69 3.73 11.9 9.2 — 15.6 18.8 6 8.30 5.25 9.2 5.7 — 14.6 16.9 7 8.82 6.41 7.2 4.3 — 14.6 16.7 8 9.48 7.33 6.4 2.8 — 15.3 16.4 9 8.66 7.49 3.5 1.6 — 14.4 14.9 10 8.66 7.95 1.8 1.1 — 13.3 14.5 11 9.16 8.13 3.1 1.5 — 14.0 14.8 12 9.99 8.63 4.1 1.6 — 14.9 15.5 13 8.86 7.91 2.9 1.4 1.3 14.6 15.0 14 9.11 8.18 2.8 1.1 1.3 14.0 14.2 15 9.00 8.17 2.5 1.3 1.3 13.9 14.6 16 9.58 8.73 2.6 1.1 — 14.6 15.1 17 4.29 3.75 1.6 1.4 — 18.7 18.6 18 3.45 3.02 1.3 1.9 — 19.0 19.3 19 3.31 2.91 1.2 1.3 — 19.2 19.6 20 3.35 2.97 1.1 1.5 — 19.2 20.1 As shown in Table 5, particularly in comparison with Tables 2 and 3, the 5 wt. % nickel and 2 wt. % tungsten catalyst was not as effective for converting HPA at a high activity rate over the entire set of batches as the catalyst used in Example 1 or Example 2.
|
C
|
C07
|
C07C
|
29
|
14
|
|||
11778440
|
US20080011129A1-20080117
|
SCREW PRESTRESSING DEVICE AND METHOD
|
ACCEPTED
|
20080102
|
20080117
|
[]
|
B25B23151
|
["B25B23151"]
|
7856909
|
20070716
|
20101228
|
81
|
057380
|
74296.0
|
SHAKERI
|
HADI
|
[{"inventor_name_last": "WEIMER", "inventor_name_first": "Peter", "inventor_city": "Markdorf", "inventor_state": "", "inventor_country": "DE"}]
|
A screw prestressing device having a piston and a draw pin structured and arranged to be disconnectably coupled to an element and movable, via the piston, to apply a defined prestressing force in the element.
|
1. A screw prestressing device comprising: a piston; and a draw pin structured and arranged to be disconnectably coupled to an element and movable, via the piston, to apply a defined prestressing force in the element. 2. The screw prestressing device of claim 1, wherein the element comprises a threaded assembly comprising: a screw; a flat washer; and a nut. 3. The screw prestressing device of claim 2, wherein the draw pin is structured and arranged to be disconnectably coupled to the screw via a threaded connection. 4. The screw prestressing device of claim 1, wherein the draw pin is movable in a pull direction. 5. The screw prestressing device of claim 1, wherein the piston comprises a water hydraulic piston. 6. The screw prestressing device of claim 1, wherein the draw pin comprises a high-strength draw pin. 7. The screw prestressing device of claim 1, further comprising a plurality of O-rings, wherein the piston is sealed with the O-rings. 8. The screw prestressing device of claim 1, further comprising a connecting adaptor structured and arranged to releasably couple a high-pressure water hand pump to the screw prestressing device for generating a water hydraulic pressure. 9. The screw prestressing device of claim 8, further comprising at least one calibrated pressure sensor structured and arranged to detect and document the water hydraulic pressure. 10. The screw prestressing device of claim 1, further comprising a bleeding device structured and arranged to bleed air locks. 11. The screw prestressing device of claim 1, further comprising a locking device structured and arranged to prevent inadmissible movements of the piston. 12. The screw prestressing device of claim 2, further comprising a cylinder, structured and arranged to guide the piston therein, having an end structured and arranged to be placed on the flat washer of the threaded assembly to be tightened. 13. The screw prestressing device of claim 12, further comprising a nut drive unit rotatably-mounted between the draw pin and the cylinder, wherein: the cylinder further comprises a nut drive opening, the nut drive unit is accessible from an outside of the cylinder via the nut drive opening, and the nut drive unit is structured and arranged to maintain the nut of the threaded assembly in a constant engagement during a tightening operation. 14. The screw prestressing device of claim 13, wherein the nut drive unit and a pin applied externally to the nut drive unit are structured and arranged to rotate the nut of the threaded assembly when the defined prestressing force has been reached until the nut is in contact with the flat washer of the threaded assembly. 15. The screw prestressing device of claim 13, wherein the nut drive unit comprises at least one hole on a circumference of the nut drive unit at a level of the nut drive opening, wherein the at least one hole is accessible from the outside of the cylinder via the nut drive opening. 16. The screw prestressing device of claim 2, further comprising a prestressing detector structured and arranged to detect a prestressing force applied to the screw. 17. The screw prestressing device of claim 16, wherein the prestressing detector comprises: a contact unit arranged within the draw pin and having an ultrasonic sensor structured and arranged to transmit and receive an ultrasonic signal; a connector structured and arranged to provide an electrical connection to the contact unit; and an insulation sleeve arranged within the draw pin, and electrically connecting the contact unit and the connector. 18. The prestressing device of claim 17, wherein the ultrasonic sensor comprises a piezo sensor. 19. The prestressing device of claim 17, wherein the contact unit is spring-loaded. 20. The prestressing device of claim 13, wherein the draw pin and the nut drive unit are interchangeable with a plurality of draw pins and a plurality of corresponding nut drive units, respectively, wherein each of the respective plurality of draw pins and each of the plurality of corresponding nut drive units is structured for a particular threaded assembly size. 21. The prestressing device of claim 2, wherein the threaded assembly has a size of or between M4 and M12. 22. A method of prestressing a threaded assembly in a screw prestressing device, comprising: disconnectably coupling a draw pin to a screw of the threaded assembly; and moving the draw pin, via a moving of a water hydraulic piston, to apply a defined prestressing force in the threaded assembly. 23. The method of claim 22, further comprising: maintaining a nut of the threaded assembly in a constant engagement during a tightening operation; and when the defined prestressing force has been reached, rotating the nut of the threaded assembly, via a nut drive unit, until the nut is in contact with a flat washer of the threaded assembly. 24. The method of claim 22, further comprising detecting a prestressing force applied to the screw by transmitting an ultrasonic signal through the screw; and receiving a reflected signal through the screw indicative the prestressing force applied to the screw. 25. The method of claim 22, further comprising detecting a prestressing force applied to the screw by at least one of a prestressing detector and sensing and documenting of water hydraulic pressure.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to a water hydraulic screw prestressing device free of torque with integrated ultrasonic prestressing monitoring. 2. Discussion of Background Information Threaded assemblies provide detachable connections of components. The important factor for these connections is the spring action of the screw and screwed parts (flange). Tightening a screw with a prestressing force causes a stretching of the screw and a compression of the flange. The resulting friction produces a connection of the two parts in the radial direction, where the prestressing force itself blocks the axial degree of freedom of the parts involved. The most common tightening methods, i.e., methods of applying a prestressing, can be divided into two groups. With the first group, the shanks of the screws are strained by the nuts being rotated. The screws, or studs, are stretched and strained by the rotary motion according to the pitch of the thread. These standard threaded assemblies have the disadvantage that if the maximum prestressing forces are utilized in the screw, or stud, torques are inevitably transferred via the unavoidable thread friction. This leads to a superimposition of the stress in the screw, or stud, (tensile stress plus shearing stress) and furthermore, to a transfer of the thread torque to the flange to be tightened. Due to the superimposition of the stress in the screw, or stud (tensile stress plus shearing stress), the threaded assembly cannot be tightened up to the maximum permissible tensile stress. Furthermore, in the case of delicate parts, such as, e.g., the ceramic mirrors of a spectrometer (e.g., in the NirSpec space project), the transfer of the thread torque to the flange to be tightened leads to an unacceptable and inadmissible deformation of the mirror surface. In the NirSpec space project (the follow-up project to the Hubble telescope) and, as expected in all future optical space projects, all optical mirrors (e.g., ceramic) have to be tightened via frictional contact and a three-screw attachment with the highest prestressing force and, as far as possible, free of torque. In-house tests with conventional tightening methods have shown that torques transferred to the ceramic mirror foot have a negative impact (i.e., performance loss) on the high demands on the mirror surface. With the second group of tightening methods, the shanks of the screws are first stretched (e.g., with the aid of hydraulic cylinders), then the nuts are applied in the stretched state of the screws, or studs. After the stretching force is removed, the connection is braced. Torsional friction effects are thus of only secondary importance; shearing stresses in the studs virtually do not occur. In the prior art, hydraulic screw prestressing units are known from the construction of nuclear power plants and wind turbine generator systems. However, these units are known only for very large threaded assemblies (from diameter M24 upwards) and all operate on the basis of oil hydraulics. A hydraulic screw prestressing device for threaded assemblies from M4 to M12 is not known in the prior art. Additionally, water hydraulic screw prestressing devices are not known in the prior art. Through the use of an oil hydraulic system, these screw prestressing devices have the disadvantage that in practice they are not suitable for cleanroom applications, such as are necessary, e.g., in applications in the field of space flight. An oil hydraulic system can be used in a cleanroom only to a limited extent, namely with special, complex additional measures. The known hydraulic screw prestressing units, which are known only for very large threaded assemblies, furthermore have the disadvantage that, in the case of damage, they would lead to a destruction of sensitive elements, e.g., highly sensitive optical elements, such as are used in the field of space flight. In space flight projects, most reduced-weight threaded assemblies have to be monitored and tightened with the highest prestressing forces. In particular, with the use of so-called optical benches, threaded assemblies are to be tightened if possible without the influence of torque, while at the same time with the highest cleanness class. Every friction produced (e.g., metal on metal, but also metal on ceramic) inevitably leads to abrasive wear, which in turn can impact the optical surfaces. The subject matter of the invention solves these problems in particular in an optimal manner.
|
<SOH> SUMMARY OF THE PRESENT INVENTION <EOH>An aim of the current invention is a screw prestressing device and method for tightening threaded assemblies, if possible, without the influence of torque, while at the highest cleanness class. According to the invention, a screw prestressing device comprises a first device that is mounted on a second device such that the first device can be moved outwards in a preferred direction to apply a defined prestressing force in the second device via a third device. Further advantageous embodiments of the invention are contained in the dependent claims. One advantage of the screw prestressing device according to the invention is that this screw prestressing device is suitable for cleanroom applications without special complex additional measures being necessary. Another advantage of the screw prestressing device according to the invention is that this screw prestressing device is suitable for applications in connection with highly sensitive optical elements; i.e., these highly sensitive optical elements are not destroyed by the use of the screw prestressing unit. Another advantage of the screw prestressing device according to the invention is that this screw prestressing device is able to tighten screws utilizing the maximum permissible prestressing, without the influence of torque, and while at the same time with the highest cleanness class. In particular, when used on so-called optical benches, threaded assemblies are to be tightened, if possible, without the influence of torque, while at the same time maintaining the highest cleanness class. Every friction produced (e.g., metal on metal, but also metal on ceramic) inevitably leads to abrasive wear, which in turn can also impact the optical surfaces. Another advantage of the screw prestressing device according to the invention is that this screw prestressing device supports the possibility of monitoring threaded assemblies during the tightening process in a two-fold manner (via hydraulic pressure monitoring and via ultrasonic stretching measurement). Another advantage of the screw prestressing device according to the invention is that this screw prestressing device is able to tighten threaded assemblies with the highest prestressing forces. Thus, for example, depending on the screw material used (e.g., titanium, steel, or inconel), the screws can be tightened to within a few percent of their permissible yield point. According to an aspect of the invention, a screw prestressing device comprises a piston, and a draw pin structured and arranged to be disconnectably coupled to a second device and to move outwards in a prestressing direction, via the piston, to apply a defined prestressing force in the second device. According to a further aspect of the invention, the element comprises a threaded assembly comprising a screw, a flat washer, and a nut. According to a further aspect of the invention, the draw pin is structured and arranged to be disconnectably coupled to the screw via a threaded connection. According to a further aspect of the invention, the draw pin is movable in a pull direction. According to a further aspect of the invention, the piston comprises a water hydraulic piston. According to a further aspect of the invention, the draw pin comprises a high-strength draw pin. According to a further aspect of the invention, the screw prestressing device further comprises a plurality of O-rings, wherein the piston is sealed with the O-rings. According to a further aspect of the invention, the screw prestressing device further comprises a connecting adaptor structured and arranged to releasably couple a high-pressure water hand pump to the screw prestressing device for generating a water hydraulic pressure. According to a further aspect of the invention, the screw prestressing device further comprises at least one calibrated pressure sensor structured and arranged to detect and document the water hydraulic pressure. According to a further aspect of the invention, the screw prestressing device further comprises a bleeding device structured and arranged to bleed air locks. According to a further aspect of the invention, the screw prestressing device further comprises a locking device structured and arranged to prevent inadmissible movements of the piston. According to a further aspect of the invention, the screw prestressing device further comprises a cylinder, structured and arranged to guide the piston therein, having an end structured and arranged to be placed on the flat washer of the threaded assembly to be tightened. According to a further aspect of the invention, the screw prestressing device further comprises a nut drive unit rotatably-mounted between the draw pin and the cylinder, wherein the cylinder further comprises a nut drive opening, the nut drive unit is accessible from an outside of the cylinder via the nut drive opening, and the nut drive unit is structured and arranged to maintain the nut of the threaded assembly in a constant engagement during a tightening operation. According to a further aspect of the invention, the nut drive unit and a pin applied externally to the nut drive unit are structured and arranged to rotate the nut of the threaded assembly when the defined prestressing force has been reached until the nut is in contact with the flat washer of the threaded assembly. According to a further aspect of the invention, the nut drive unit comprises at least one hole on a circumference of the nut drive unit at a level of the nut drive opening, wherein the at least one hole is accessible from the outside of the cylinder via the nut drive opening. According to a further aspect of the invention, the screw prestressing device further comprises a prestressing detector structured and arranged to detect a prestressing force applied to the screw. According to a further aspect of the invention, the prestressing detector comprises a contact unit arranged within the draw pin and having an ultrasonic sensor structured and arranged to transmit and receive an ultrasonic signal, a connector structured and arranged to provide an electrical connection to the contact unit, and an insulation sleeve arranged within the draw pin, and electrically connecting the contact unit and the connector. According to a further aspect of the invention, the ultrasonic sensor comprises a piezo sensor. According to a further aspect of the invention, the contact unit is spring-loaded. According to a further aspect of the invention, the draw pin and the nut drive unit are interchangeable with a plurality of draw pins and a plurality of corresponding nut drive units, respectively, wherein each of the respective plurality of draw pins and each of the plurality of corresponding nut drive units is structured for a particular threaded assembly size. According to a further aspect of the invention, the threaded assembly has a size of or between M4 and M12. According to a further aspect of the invention, a method of prestressing a threaded assembly in a screw prestressing device comprises disconnectably coupling a draw pin to a screw of the threaded assembly, and moving the draw pin, via a moving of a water hydraulic piston, to apply a defined prestressing force in the threaded assembly. According to a further aspect of the invention, a method of prestressing a threaded assembly in a screw prestressing device further comprises maintaining a nut of the threaded assembly in a constant engagement during a tightening operation, and when the defined prestressing force has been reached, rotating the nut of the threaded assembly, via a nut drive unit, until the nut is in contact with a flat washer of the threaded assembly. According to a further aspect of the invention, a method of prestressing a threaded assembly in a screw prestressing device further comprises detecting a prestressing force applied to the screw by transmitting an ultrasonic signal through the screw and receiving a reflected signal through the screw indicative the prestressing force applied to the screw. According to a further aspect of the invention, a method of prestressing a threaded assembly in a screw prestressing device further comprises detecting a prestressing force applied to the screw by at least one of a prestressing detector and sensing and documenting of water hydraulic pressure.
|
CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority under 35 U.S.C. § 119 of German Application No. 10 2006 033 320.9-12 filed Jul. 17, 2006, the disclosure of which is expressly incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a water hydraulic screw prestressing device free of torque with integrated ultrasonic prestressing monitoring. 2. Discussion of Background Information Threaded assemblies provide detachable connections of components. The important factor for these connections is the spring action of the screw and screwed parts (flange). Tightening a screw with a prestressing force causes a stretching of the screw and a compression of the flange. The resulting friction produces a connection of the two parts in the radial direction, where the prestressing force itself blocks the axial degree of freedom of the parts involved. The most common tightening methods, i.e., methods of applying a prestressing, can be divided into two groups. With the first group, the shanks of the screws are strained by the nuts being rotated. The screws, or studs, are stretched and strained by the rotary motion according to the pitch of the thread. These standard threaded assemblies have the disadvantage that if the maximum prestressing forces are utilized in the screw, or stud, torques are inevitably transferred via the unavoidable thread friction. This leads to a superimposition of the stress in the screw, or stud, (tensile stress plus shearing stress) and furthermore, to a transfer of the thread torque to the flange to be tightened. Due to the superimposition of the stress in the screw, or stud (tensile stress plus shearing stress), the threaded assembly cannot be tightened up to the maximum permissible tensile stress. Furthermore, in the case of delicate parts, such as, e.g., the ceramic mirrors of a spectrometer (e.g., in the NirSpec space project), the transfer of the thread torque to the flange to be tightened leads to an unacceptable and inadmissible deformation of the mirror surface. In the NirSpec space project (the follow-up project to the Hubble telescope) and, as expected in all future optical space projects, all optical mirrors (e.g., ceramic) have to be tightened via frictional contact and a three-screw attachment with the highest prestressing force and, as far as possible, free of torque. In-house tests with conventional tightening methods have shown that torques transferred to the ceramic mirror foot have a negative impact (i.e., performance loss) on the high demands on the mirror surface. With the second group of tightening methods, the shanks of the screws are first stretched (e.g., with the aid of hydraulic cylinders), then the nuts are applied in the stretched state of the screws, or studs. After the stretching force is removed, the connection is braced. Torsional friction effects are thus of only secondary importance; shearing stresses in the studs virtually do not occur. In the prior art, hydraulic screw prestressing units are known from the construction of nuclear power plants and wind turbine generator systems. However, these units are known only for very large threaded assemblies (from diameter M24 upwards) and all operate on the basis of oil hydraulics. A hydraulic screw prestressing device for threaded assemblies from M4 to M12 is not known in the prior art. Additionally, water hydraulic screw prestressing devices are not known in the prior art. Through the use of an oil hydraulic system, these screw prestressing devices have the disadvantage that in practice they are not suitable for cleanroom applications, such as are necessary, e.g., in applications in the field of space flight. An oil hydraulic system can be used in a cleanroom only to a limited extent, namely with special, complex additional measures. The known hydraulic screw prestressing units, which are known only for very large threaded assemblies, furthermore have the disadvantage that, in the case of damage, they would lead to a destruction of sensitive elements, e.g., highly sensitive optical elements, such as are used in the field of space flight. In space flight projects, most reduced-weight threaded assemblies have to be monitored and tightened with the highest prestressing forces. In particular, with the use of so-called optical benches, threaded assemblies are to be tightened if possible without the influence of torque, while at the same time with the highest cleanness class. Every friction produced (e.g., metal on metal, but also metal on ceramic) inevitably leads to abrasive wear, which in turn can impact the optical surfaces. The subject matter of the invention solves these problems in particular in an optimal manner. SUMMARY OF THE PRESENT INVENTION An aim of the current invention is a screw prestressing device and method for tightening threaded assemblies, if possible, without the influence of torque, while at the highest cleanness class. According to the invention, a screw prestressing device comprises a first device that is mounted on a second device such that the first device can be moved outwards in a preferred direction to apply a defined prestressing force in the second device via a third device. Further advantageous embodiments of the invention are contained in the dependent claims. One advantage of the screw prestressing device according to the invention is that this screw prestressing device is suitable for cleanroom applications without special complex additional measures being necessary. Another advantage of the screw prestressing device according to the invention is that this screw prestressing device is suitable for applications in connection with highly sensitive optical elements; i.e., these highly sensitive optical elements are not destroyed by the use of the screw prestressing unit. Another advantage of the screw prestressing device according to the invention is that this screw prestressing device is able to tighten screws utilizing the maximum permissible prestressing, without the influence of torque, and while at the same time with the highest cleanness class. In particular, when used on so-called optical benches, threaded assemblies are to be tightened, if possible, without the influence of torque, while at the same time maintaining the highest cleanness class. Every friction produced (e.g., metal on metal, but also metal on ceramic) inevitably leads to abrasive wear, which in turn can also impact the optical surfaces. Another advantage of the screw prestressing device according to the invention is that this screw prestressing device supports the possibility of monitoring threaded assemblies during the tightening process in a two-fold manner (via hydraulic pressure monitoring and via ultrasonic stretching measurement). Another advantage of the screw prestressing device according to the invention is that this screw prestressing device is able to tighten threaded assemblies with the highest prestressing forces. Thus, for example, depending on the screw material used (e.g., titanium, steel, or inconel), the screws can be tightened to within a few percent of their permissible yield point. According to an aspect of the invention, a screw prestressing device comprises a piston, and a draw pin structured and arranged to be disconnectably coupled to a second device and to move outwards in a prestressing direction, via the piston, to apply a defined prestressing force in the second device. According to a further aspect of the invention, the element comprises a threaded assembly comprising a screw, a flat washer, and a nut. According to a further aspect of the invention, the draw pin is structured and arranged to be disconnectably coupled to the screw via a threaded connection. According to a further aspect of the invention, the draw pin is movable in a pull direction. According to a further aspect of the invention, the piston comprises a water hydraulic piston. According to a further aspect of the invention, the draw pin comprises a high-strength draw pin. According to a further aspect of the invention, the screw prestressing device further comprises a plurality of O-rings, wherein the piston is sealed with the O-rings. According to a further aspect of the invention, the screw prestressing device further comprises a connecting adaptor structured and arranged to releasably couple a high-pressure water hand pump to the screw prestressing device for generating a water hydraulic pressure. According to a further aspect of the invention, the screw prestressing device further comprises at least one calibrated pressure sensor structured and arranged to detect and document the water hydraulic pressure. According to a further aspect of the invention, the screw prestressing device further comprises a bleeding device structured and arranged to bleed air locks. According to a further aspect of the invention, the screw prestressing device further comprises a locking device structured and arranged to prevent inadmissible movements of the piston. According to a further aspect of the invention, the screw prestressing device further comprises a cylinder, structured and arranged to guide the piston therein, having an end structured and arranged to be placed on the flat washer of the threaded assembly to be tightened. According to a further aspect of the invention, the screw prestressing device further comprises a nut drive unit rotatably-mounted between the draw pin and the cylinder, wherein the cylinder further comprises a nut drive opening, the nut drive unit is accessible from an outside of the cylinder via the nut drive opening, and the nut drive unit is structured and arranged to maintain the nut of the threaded assembly in a constant engagement during a tightening operation. According to a further aspect of the invention, the nut drive unit and a pin applied externally to the nut drive unit are structured and arranged to rotate the nut of the threaded assembly when the defined prestressing force has been reached until the nut is in contact with the flat washer of the threaded assembly. According to a further aspect of the invention, the nut drive unit comprises at least one hole on a circumference of the nut drive unit at a level of the nut drive opening, wherein the at least one hole is accessible from the outside of the cylinder via the nut drive opening. According to a further aspect of the invention, the screw prestressing device further comprises a prestressing detector structured and arranged to detect a prestressing force applied to the screw. According to a further aspect of the invention, the prestressing detector comprises a contact unit arranged within the draw pin and having an ultrasonic sensor structured and arranged to transmit and receive an ultrasonic signal, a connector structured and arranged to provide an electrical connection to the contact unit, and an insulation sleeve arranged within the draw pin, and electrically connecting the contact unit and the connector. According to a further aspect of the invention, the ultrasonic sensor comprises a piezo sensor. According to a further aspect of the invention, the contact unit is spring-loaded. According to a further aspect of the invention, the draw pin and the nut drive unit are interchangeable with a plurality of draw pins and a plurality of corresponding nut drive units, respectively, wherein each of the respective plurality of draw pins and each of the plurality of corresponding nut drive units is structured for a particular threaded assembly size. According to a further aspect of the invention, the threaded assembly has a size of or between M4 and M12. According to a further aspect of the invention, a method of prestressing a threaded assembly in a screw prestressing device comprises disconnectably coupling a draw pin to a screw of the threaded assembly, and moving the draw pin, via a moving of a water hydraulic piston, to apply a defined prestressing force in the threaded assembly. According to a further aspect of the invention, a method of prestressing a threaded assembly in a screw prestressing device further comprises maintaining a nut of the threaded assembly in a constant engagement during a tightening operation, and when the defined prestressing force has been reached, rotating the nut of the threaded assembly, via a nut drive unit, until the nut is in contact with a flat washer of the threaded assembly. According to a further aspect of the invention, a method of prestressing a threaded assembly in a screw prestressing device further comprises detecting a prestressing force applied to the screw by transmitting an ultrasonic signal through the screw and receiving a reflected signal through the screw indicative the prestressing force applied to the screw. According to a further aspect of the invention, a method of prestressing a threaded assembly in a screw prestressing device further comprises detecting a prestressing force applied to the screw by at least one of a prestressing detector and sensing and documenting of water hydraulic pressure. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is further described in the detailed description which follows, in reference to the noted plurality of drawings by way of non-limiting examples of exemplary embodiments of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein: FIG. 1 shows the prestressing device according to the invention; FIG. 2 shows an external view of the prestressing device according to the invention; FIG. 3 shows a plan view of the prestressing device according to the invention; and FIG. 4 shows the prestressing device according to the invention placed on a threaded assembly. DETAILED DESCRIPTION OF THE INVENTION The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice. Embodiments of the screw prestressing device according to the invention are described below in connection with the drawings. The invention relates to a water hydraulic screw prestressing unit that is suitable in particular for small screw diameters (e.g., from M4 to M12 of the metric ISO standard, or equivalent sizes). However, the invention is not restricted to screw diameters from M4 to M12. Rather, the invention is suitable for all screw diameters. In particular, the water hydraulic system does not restrict the application for large screws, since the maximum possible water pressure can be consistently adjusted by enlarging the piston. FIG. 1 shows a screw prestressing device 1 according to the invention. A high-strength draw pin 2 is screwed on the thread of a threaded assembly 17 (see FIG. 4), wherein the thread projects into draw pin 2 a distance 18 of at least 1.5 d, wherein d is the thread diameter of the screw or the stud. According to the invention, the draw pin 2 is moved outwards (upwards) in a pull direction 3 to apply a defined prestressing force in the threaded assembly 17. The force is applied via a water hydraulic piston 4 sealed with O-rings 5. Since it is contemplated that high-strength threaded assemblies may be tightened by the present invention, the thread of the draw pin 2 must have at least the strength of the highest strength threaded assembly 17 that is to be tightened. This strength of the draw pin 2 corresponds approximately to a yield point of greater than or equal to 1000 N/mm2. The water hydraulic pressure is generated via a commercial high-pressure water hand pump (not shown) and read out and documented via calibrated pressure sensors (not shown). The hydraulic prestressing device 1 is connected to the commercial high-pressure water hand pump, with the aid of a commercial high-pressure metal pleated hose, via the connecting adapter 6 of the prestressing device 1. Any air locks can be bled via the bleed screw 7 before startup. The piston 4 is guided in a cylinder 8. Additionally, an end 19 (see FIGS. 2 and 3) of the cylinder 8 is supported or placed on a flat washer (not shown) of the threaded assembly 17 to be tightened (shown in FIG. 4). The applied prestressing force leads to a stretching of the threaded assembly 17 and to the lifting of the nut of the threaded assembly 17, which was previously applied only with manual force. Inadmissible piston paths are prevented via the snap ring 9 (mechanical stop). The nut of the threaded assembly 17 is in constant engagement during the tightening operation with a nut drive unit 10 that is rotatably mounted between draw pin 2 and cylinder 8 and accessible from outside via the nut drive opening 11 (see FIG. 2). Once the defined prestressing force has been reached, the nut of the threaded assembly 17 is rotated clockwise via the nut drive unit 10 and a pin (not shown) applied externally to the nut drive unit 10 until the nut is in contact with the flat washer of the threaded assembly 17. To this end, the nut drive unit 10 has one or more holes 12 drilled around the circumference of the nut drive unit 10 at a level of the nut drive opening 11. Further, as shown in FIG. 2, these holes 12 may be accessible from outside the cylinder 8. If nine holes 12 are used, for example, the nut of the threaded assembly can be applied via these holes 12 in 40° steps in a torque-free manner. In the case of a different number of holes 12 being used, the number of degrees of the steps is altered accordingly. In order to facilitate a prestressing of threaded assemblies having different thread sizes, both the draw pin 2 and the nut drive unit 10 may be replaced with a few hand movements. More specifically, the draw pin 2 may be pulled off upwards, the nut drive unit 10 may be removed downwards after a setscrew 13 has been opened. Furthermore, the invention relates to a device that comprises the above-described screw prestressing device 1, and additionally a prestressing detector device, which detects the prestressing during the tightening operation. This prestressing detection device comprises a commercially available ultrasonic measuring unit (not shown). Additionally, the prestressing detector device comprises a spring-loaded contact unit 14, which is integrated into the draw pin unit 2 (which may differ according to thread size) via an insulation sleeve 15. The contact unit 14 can control and read out an ultrasonic sensor (e.g., an ultrasonic piezo sensor) mounted on a thread overhang. An electrical connection to the contact unit 14 is made via a commercial plug-and-socket connector 16 (e.g., a bayonet Neill-Concelman (BNC) connector). In the case of the ultrasonic piezo sensor, an ultrasonic signal is transmitted via a piezo element to the opposite end of the threaded assembly, reflected there and received by the piezo element again. The real stretching of the threaded assembly can be detected via the different run length of the signal. Thus, the existing prestressing in the screw, or stud, can be read out and documented. Additionally, according to a further aspect of the invention, the prestressing may be measured and quantified by utilizing the pressure readings of the water hydraulic pressure from the pressure sensors. Thus, according to the invention, small to medium-sized (e.g., diameters M4 to M12), high-strength threaded assemblies, monitored and documented in a twofold manner (by hydraulic pressure and ultrasonic measurement) with the aid of the water hydraulic screw prestressing device 1, can be tightened up to the limit of their load capacity without any torque superimposition. The screw prestressing device 1 is suitable in particular for use in space integration rooms, since no impermissible contaminations or no contaminations that cannot be easily removed occur even in the event of technical failure (water as hydraulic medium, lowest volumes in the high-pressure area (approx. 3 to 10 cm3)). Through the use of the prestressing unit 1, threaded assemblies can be optimized in terms of weight within space applications. Moreover, losses of performance/efficiency caused by torque are reduced to a minimum, in particular with the use of optical satellites. It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
|
B
|
B25
|
B25B
|
231
|
51
|
|||
11744758
|
US20070204252A1-20070830
|
Methods and Systems for Placement
|
ACCEPTED
|
20070815
|
20070830
|
[]
|
G06F1750
|
["G06F1750"]
|
7669160
|
20070504
|
20100223
|
716
|
009000
|
98137.0
|
TAT
|
BINH
|
[{"inventor_name_last": "Furnish", "inventor_name_first": "Geoffrey", "inventor_city": "Austin", "inventor_state": "TX", "inventor_country": "US"}, {"inventor_name_last": "LeBrun", "inventor_name_first": "Maurice", "inventor_city": "Austin", "inventor_state": "TX", "inventor_country": "US"}, {"inventor_name_last": "Bose", "inventor_name_first": "Subhasis", "inventor_city": "Austin", "inventor_state": "TX", "inventor_country": "US"}]
|
Simultaneous Dynamical Integration modeling techniques are applied to placement of elements of integrated circuits as described by netlists specifying interconnection of devices. Solutions to a system of coupled ordinary differential equations in accordance with Newtonian mechanics are approximated by numerical integration. A resultant time-evolving system of nodes moves through a continuous location space in continuous time, and is used to derive placements of the devices having one-to-one correspondences with the nodes. Nodes under the influence of net attractive forces, computed based on the interconnections between the morphable devices, tend to coalesce into well-organized topologies. Nodes are also affected by spreading forces determined by density fields that are developed based on local spatial node populations. The forces are optionally selectively modulated as a function of simulation time. The placements of the devices are compatible with various design flows, such as standard cell, structured array, gate array, and field-programmable gate array.
|
1. A method of generating a cell placement from a circuit netlist, the method comprising: modeling the circuit netlist as an analogous continuous dynamic physical system of nodes and nets of a first plurality of the nodes, wherein a second plurality of the nodes are represented by analogous physical state variables including position and velocity; formulating a system of continuous coupled simultaneous ordinary differential equations describing motion of the nodes and the nets in accordance with a plurality of forces including attractive and spreading forces; and integrating the equations of motion to at least approximate a continuous evolution of the analogous physical state variables over time. 2. The method of claim 1, wherein the analogous physical state variables representing the second plurality of nodes further include mass. 3. The method of claim 1, further wherein; the cell placement is adapted for use in a circuit layout to specify locations for a plurality of cells, the circuit netlist representing the cells and interconnect between the cells, the circuit layout including the cell placement; and the modeling, the formulating, and the integrating are performed at least in part to perform a global placement that determines an initial placement of the cells. 4. The method of claim 3, wherein the circuit layout further includes routing of the interconnect. 5. The method of claim 1, wherein at least some of the attractive forces include connectivity forces corresponding to at least some interconnections described by the circuit netlist. 6. The method of claim 5, wherein the connectivity forces bias movement of at least a portion of the nodes to shorten at least some of the interconnections. 7. The method of claim 1, wherein at least some of the attractive forces include retention forces corresponding to at least some grouping constraints arising from predetermined requirements. 8. The method of claim 7, wherein the predetermined requirements include layout floorplanning requirements. 9. The method of claim 1, wherein at least some of the spreading forces correspond to spatial concentrations of at least some of the nodes. 10. The method of claim 1, wherein at least some of the spreading forces include exclusion forces corresponding to predetermined layout floorplan constraints. 11. The method of claim 10, wherein the layout floorplan constraints include reserved locations for at least some floorplan elements. 12. The method of claim 1, wherein at least a portion of the circuit netlist is a gate-level netlist. 13. A computer readable medium having a set of instructions stored therein which when executed by a processing device causes the processing device to perform procedures comprising: modeling a circuit netlist as an analogous continuous dynamic physical system of nodes and nets of a first plurality of the nodes, wherein a second plurality of the nodes are represented by analogous physical state variables including position, velocity, and mass; formulating a system of continuous coupled simultaneous ordinary differential equations describing motion of the nodes and the nets in accordance with a plurality of forces including attractive and spreading forces; integrating the equations of motion to at least approximate a continuous evolution of the analogous physical state variables over time; and generating a cell placement from the circuit netlist in accordance with the modeling, the formulating, and the integrating. 14. The computer readable medium of claim 13, wherein at least some of the attractive forces include connectivity forces corresponding to at least some interconnections described by the circuit netlist. 15. The computer readable medium of claim 13, wherein at least some of the attractive forces include retention forces corresponding to at least some grouping constraints determined from predetermined requirements. 16. The computer readable medium of claim 13, wherein at least some of the spreading forces correspond to spatial concentrations of at least some of the nodes. 17. The computer readable medium of claim 13, wherein at least some of the spreading forces include exclusion forces corresponding to predetermined layout floorplan constraints. 18. The computer readable medium of claim 13, wherein at least a portion of the circuit netlist is a gate-level netlist. 19. A method comprising: modeling a circuit netlist as an analogous continuous dynamic physical system of nodes and nets of a first plurality of the nodes, wherein a second plurality of the nodes are represented by analogous physical state variables including position, velocity, and mass; integrating a system of continuous coupled simultaneous ordinary differential equations describing motion of the nodes and the nets in accordance with a plurality of forces to at least approximate a continuous evolution of the analogous physical state variables over time; and generating a cell placement from the circuit netlist in accordance with the modeling, the formulating, and the integrating. 20. The method of claim 19, wherein at least one of the forces is an attractive connectivity force corresponding to at least one interconnection described by the circuit netlist. 21. The method of claim 19, wherein at least one of the forces is an attractive retention force corresponding to at least one grouping constraint determined from predetermined requirements. 22. The method of claim 19, wherein at least one of the forces is a spreading force corresponding to at least one spatial concentration of at least a portion of the nodes. 23. The method of claim 19, wherein at least one of the forces is an exclusion spreading force corresponding to at least one predetermined layout floorplan constraint. 24. The method of claim 19, wherein at least a portion of the circuit netlist is a gate-level netlist. 25. A system comprising: means for modeling a circuit netlist as an analogous continuous dynamic physical system of nodes and nets of a first plurality of the nodes, wherein a second plurality of the nodes are represented by analogous physical state variables including position, velocity, and mass; means for integrating a system of continuous coupled simultaneous ordinary differential equations describing motion of the nodes and the nets in accordance with a plurality of forces to at least approximate a continuous evolution of the analogous physical state variables over time; and means for generating a cell placement from the circuit netlist in accordance with the means for modeling, the means for formulating, and the means for integrating. 26. The system of claim 25, wherein the forces comprise attractive forces and spreading forces. 27. The system of claim 26, wherein at least some of the attractive forces include connectivity forces corresponding to at least some interconnections described by the netlist.
|
<SOH> BACKGROUND <EOH>1. Field Advancements in integrated circuit design, including placement and routing of elements in a Computer Aided Design (CAD) context, are needed to provide improvements in performance, efficiency, and utility of use. 2. Related Art Unless expressly identified as being publicly or well known, mention herein of techniques and concepts, including for context, definitions, or comparison purposes, should not be construed as an admission that such techniques and concepts are previously publicly known or otherwise part of the prior art. All references cited herein (if any), including patents, patent applications, and publications, are hereby incorporated by reference in their entireties, whether specifically incorporated or not, for all purposes.
|
<SOH> BRIEF DESCRIPTION OF DRAWINGS <EOH>FIG. 1 is a flow diagram illustrating selected details of an embodiment of placing, routing, analyzing, and generating fabrication data for any portion of an integrated circuit according to a Simultaneous Dynamical Integration (SDI)-based flow. FIG. 2 is a flow diagram illustrating selected details of an embodiment of placing and routing any portion of an integrated circuit according to an SDI-based flow. FIG. 3A is a flow diagram illustrating selected details of an embodiment of global placement according to SDI-based modeling and simulation. FIG. 3B is a flow diagram illustrating selected details of an embodiment of initial placement operations for global placement. FIG. 3C is a flow diagram illustrating selected details of an embodiment of density field based force component computation. FIG. 3D is a flow diagram illustrating selected details of an embodiment of gate density accumulation. FIG. 3E is a conceptual diagram illustrating an embodiment of two-point interpolation of node mass to grid points. FIG. 3F is a conceptual diagram illustrating an embodiment of three-point interpolation of node mass to grid points. FIG. 3G is a conceptual diagram illustrating an embodiment of applying boundary grid point masses to interior grid points. FIG. 3H is a flow diagram illustrating selected details of an embodiment of digital density filtering. FIG. 3I is a flow diagram illustrating selected details of an embodiment of interpolating gate fields to nodes. FIG. 4 is a flow diagram illustrating selected details of an embodiment of SDI-based modeling and simulation. FIG. 5A is a flow diagram illustrating selected details of a first embodiment of resource reconciliation, as a first example of legalization. FIG. 5B is a flow diagram illustrating selected details of a second embodiment of resource reconciliation, as a second example of legalization. FIG. 5C is a flow diagram illustrating selected details of an embodiment of partitioning. FIG. 6 is a flow diagram illustrating selected details of an embodiment of detailed placement (also referred to as detail placement elsewhere herein). FIG. 7A is a flow diagram illustrating selected aspects of an embodiment of delay path reduction and minimization, as an example of timing closure. FIG. 7B illustrates a conceptual view of selected elements of an embodiment of timing-driven forces. FIG. 7C illustrates a spatial organization of the driver and the coupled loads of FIG. 7B . FIG. 7D illustrates an embodiment of Net Boundary Box (NBB) estimation of routing to cover the driver and the loads of FIG. 7C . FIG. 7E illustrates an embodiment of a rectilinear Steiner Route Tree (SRT) estimation to cover the driver and loads of FIG. 7C . FIG. 7F illustrates an embodiment of estimated RC parasitics associated with the RST of FIG. 7E . FIGS. 8A and 8B collectively are a flow diagram illustrating selected details of an embodiment of an integrated circuit Electronic Design Automation (EDA) flow using one or more techniques including SDI-directed global placement, legalization, legalization-driven detailed placement, timing optimization, and routing. FIG. 9 illustrates selected details of an embodiment of manufacturing integrated circuits, the circuits being designed in part based on SDI-directed design techniques. FIG. 10 illustrates selected details of an embodiment of a computer system to execute EDA routines to perform SDI-directed place and route operations. FIG. 11 illustrates an embodiment of an SDI-based detailed placement flow. FIGS. 12A and 12B illustrate concepts relating to an embodiment of netlist elaboration. FIG. 13 illustrates an embodiment of detailed placement of a Q-block. FIG. 14 illustrates an embodiment of an additional pass of detailed placement of a Q-block. FIG. 15A illustrates a form of the form-level net of FIG. 12A . In this view the resource-level nodes are shown internal to the form. FIG. 15B illustrates another form that uses different resources to implement the same function as the form of FIG. 15A . In at least one embodiment, the form of FIG. 15B is substituted for the form of FIG. 15A through a morphing process. FIG. 16A illustrates the supply and demand for resources R 1 through R 6 corresponding to target functions of an integrated circuit design having a first selection of forms for the target functions. For at least some of the resources, the demand exceeds the available supply. FIG. 16B illustrates the supply and demand for resources R 1 through R 6 for the same target functions, but using a second selection of forms for the target functions obtained by morphing certain forms to use different resources. For each of the resources shown, the demand is less than or equal to the supply. FIG. 17A illustrates an example circuit with a plurality of critical paths. FIG. 17B illustrates example computations relating to an embodiment of CPF scoring. FIG. 18 illustrates an embodiment of a cascade of buffers of increasing drive strength. FIG. 19 illustrates example computations relating to an embodiment of SDF calculation. FIG. 20A illustrates an overall procedural control flow in an illustrative relative slack embodiment. FIG. 20B illustrates the adjustment of timing driven weight in the relative slack embodiment of FIG. 20A . FIG. 21A illustrates a driver in the interior of a net bounding box region. FIG. 21B illustrates a driver to one side of a net bounding box region. FIGS. 22A and 22B illustrate an example circuit excerpt before and after processing according to an embodiment of timing driven buffering and resizing for an array architecture. FIG. 23 illustrates a flow diagram of an integrated circuit design flow including an embodiment of processing in accordance with an embodiment of timing driven buffering and resizing for an array architecture. FIG. 24A illustrates a top-level view of an embodiment of timing driven buffering and resizing for an array architecture. FIG. 24B illustrates a detail view of selected details of an embodiment of timing driven resizing for an array architecture. FIGS. 25A and 25B illustrate an example route tree as processed by an embodiment of segmenting a portion of the route for timing driven buffering and resizing. FIG. 26 illustrates example results of an embodiment of logic replication and tunneling for an array architecture. FIG. 27 illustrates a control flow in an illustrative embodiment, as used for density modification. FIG. 28 illustrates a control flow of an illustrative embodiment, as used to determine the Steiner-cuts congestion term on the SDI grid. FIG. 29 illustrates procedures of an illustrative embodiment, showing creation of a congestion array. FIG. 30 illustrates procedures of an illustrative embodiment, showing calculation of a final congestion density enhancement array. FIG. 31 illustrates an embodiment of a processing flow for node tunneling out of exclusion zones in an SDI-based integrated circuit design flow. FIG. 32 illustrates an embodiment of SDI-related force calculations in a tunneling congestion relief context. FIG. 33 illustrates an embodiment of evaluation of tunneling transition criteria. FIG. 34A illustrates an example clock tree suitable for input to a Clock Tree Synthesis (CTS) tool for Structured Array Fabric (SAF)-based design flows. FIG. 34B illustrates an example clock tree output from the CTS tool operating on the input illustrated in FIG. 34A . FIG. 34C illustrates an example clock tree network. FIG. 35 illustrates an overview of an embodiment of a CTS flow. FIG. 36A illustrates an example die floorplan of a design having embedded Random Access Memory (RAM) or other Intellectual Property (IP) blocks. FIG. 36B illustrates a portion of a clock net in a context of a portion of FIG. 36A . FIG. 37A illustrates an example of timing driven pin swapping. FIG. 37B illustrates an example of effects of clock tree partitioning. FIG. 38 illustrates an analysis according to an embodiment of clock domain and sub-domain partitioning. detailed-description description="Detailed Description" end="lead"?
|
CROSS REFERENCE TO RELATED APPLICATIONS Priority benefit claims for this application are made in the accompanying Application Data Sheet, Request, or Transmittal (as appropriate, if any). To the extent permitted by the type of the instant application, this application incorporates by reference for all purposes the following applications, all owned by the owner of the instant application: PCT Application Serial No. PCT/US2006/025294 (Docket No. LS.2006.01B), filed Jun. 28, 2006, first named inventor Geoffrey Mark Furnish, and entitled METHODS AND SYSTEMS FOR PLACEMENT; U.S. Provisional Application Ser. No. 60/805,086 (Docket No. LS.2006.01PB), filed Jun. 18, 2006, first named inventor Geoffrey Mark Furnish, and entitled METHODS AND SYSTEMS FOR PLACEMENT AND ROUTING; U.S. Provisional Application Ser. No. 60/804,826 (Docket No. LS.2006.14), filed Jun. 15, 2006, first named inventor Geoffrey Mark Furnish, and entitled SIMULTANEOUS DYNAMICAL INTEGRATION APPLIED TO DETAILED PLACEMENT U.S. Provisional Application Ser. No. 60/804,690 (Docket No. LS.2006.13), filed Jun. 14, 2006, first named inventor Subhasis Bose, and entitled GENERALIZED CLOCK TREE SYNTHESIS FOR STRUCTURED ARRAY FABRIC; U.S. Provisional Application Ser. No. 60/804,643 (Docket No. LS.2006.11), filed Jun. 13, 2006, first named inventor Maurice J. LeBrun, and entitled TUNNELING AS A BOUNDARY CONGESTION RELIEF MECHANISM; U.S. Provisional Application Ser. No. 60/804,574 (Docket No. LS.2006.05), filed Jun. 13, 2006, first named inventor Maurice J. LeBrun, and entitled INCREMENTAL RELATIVE SLACK TIMING FORCE MODEL; U.S. Provisional Application Ser. No. 60/804,448 (Docket No. LS.2006.10), filed Jun. 12, 2006, first named inventor Maurice J. LeBrun, and entitled NODE SPREADING VIA ARTIFICIAL DENSITY ENHANCEMENT AS A MEANS TO REDUCE ROUTING CONGESTION; U.S. Provisional Application Ser. No. 60/804,173 (Docket No. LS.2006.09), filed Jun. 8, 2006, first named inventor Geoffrey Mark Furnish, and entitled MORPHING FOR GLOBAL PLACEMENT USING INTEGER LINEAR PROGRAMMING; U.S. Provisional Application Ser. No. 60/803,032 (Docket No. LS.2006.06), filed May 24, 2006, first named inventor Subhasis Bose, and entitled TIMING DRIVEN FORCE DIRECTED PLACEMENT FLOW; U.S. Provisional Application Ser. No. 60/747,651 (Docket No. LS.2006.07), filed May 18, 2006, first named inventor Subhasis Bose, and entitled TIMING DRIVEN BUFFERING AND RESIZING FOR STRUCTURED ARRAY ARCHITECTURES; U.S. Provisional Application Ser. No. 60/697,902 (Docket No. LS.2005.01C), filed Jul. 9, 2005, first named inventor Geoffrey Furnish, and entitled METHODS AND SYSTEMS FOR PLACEMENT AND ROUTING; U.S. Provisional Application Ser. No. 60/696,661 (Docket No. LS.2005.01B), filed Jul. 5, 2005, first named inventor Geoffrey Furnish, and entitled METHODS AND SYSTEMS FOR PLACEMENT AND ROUTING; and U.S. Provisional Application Ser. No. 60/694,949 (Docket No. LS.2005.01), filed Jun. 29, 2005, first named inventor Geoffrey Furnish, and entitled METHODS AND SYSTEMS FOR PLACEMENT AND ROUTING; and U.S. application Ser. No. 10/447,465 (Docket No. 6485.00002), filed May 28, 2003, first named inventor Eric Dellinger, and entitled MODULAR ARRAY DEFINED BY STANDARD CELL LOGIC. BACKGROUND 1. Field Advancements in integrated circuit design, including placement and routing of elements in a Computer Aided Design (CAD) context, are needed to provide improvements in performance, efficiency, and utility of use. 2. Related Art Unless expressly identified as being publicly or well known, mention herein of techniques and concepts, including for context, definitions, or comparison purposes, should not be construed as an admission that such techniques and concepts are previously publicly known or otherwise part of the prior art. All references cited herein (if any), including patents, patent applications, and publications, are hereby incorporated by reference in their entireties, whether specifically incorporated or not, for all purposes. Synopsis The invention may be implemented in numerous ways, including as a process, an article of manufacture, an apparatus, a system, a composition of matter, and a computer readable medium such as a computer readable storage medium or a computer network wherein program instructions are sent over optical or electronic communication links. In this specification, these implementations, or any other form that the invention may take, may be referred to as techniques. The Detailed Description provides an exposition of one or more embodiments of the invention that enable improvements in performance, efficiency, and utility of use in the field identified above. The Detailed Description includes an Introduction to facilitate the more rapid understanding of the remainder of the Detailed Description. The Introduction includes Example Embodiments of one or more of systems, methods, articles of manufacture, and computer readable media in accordance with the concepts described herein. As is discussed in more detail in the Conclusions, the invention encompasses all possible modifications and variations within the scope of the issued claims. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a flow diagram illustrating selected details of an embodiment of placing, routing, analyzing, and generating fabrication data for any portion of an integrated circuit according to a Simultaneous Dynamical Integration (SDI)-based flow. FIG. 2 is a flow diagram illustrating selected details of an embodiment of placing and routing any portion of an integrated circuit according to an SDI-based flow. FIG. 3A is a flow diagram illustrating selected details of an embodiment of global placement according to SDI-based modeling and simulation. FIG. 3B is a flow diagram illustrating selected details of an embodiment of initial placement operations for global placement. FIG. 3C is a flow diagram illustrating selected details of an embodiment of density field based force component computation. FIG. 3D is a flow diagram illustrating selected details of an embodiment of gate density accumulation. FIG. 3E is a conceptual diagram illustrating an embodiment of two-point interpolation of node mass to grid points. FIG. 3F is a conceptual diagram illustrating an embodiment of three-point interpolation of node mass to grid points. FIG. 3G is a conceptual diagram illustrating an embodiment of applying boundary grid point masses to interior grid points. FIG. 3H is a flow diagram illustrating selected details of an embodiment of digital density filtering. FIG. 3I is a flow diagram illustrating selected details of an embodiment of interpolating gate fields to nodes. FIG. 4 is a flow diagram illustrating selected details of an embodiment of SDI-based modeling and simulation. FIG. 5A is a flow diagram illustrating selected details of a first embodiment of resource reconciliation, as a first example of legalization. FIG. 5B is a flow diagram illustrating selected details of a second embodiment of resource reconciliation, as a second example of legalization. FIG. 5C is a flow diagram illustrating selected details of an embodiment of partitioning. FIG. 6 is a flow diagram illustrating selected details of an embodiment of detailed placement (also referred to as detail placement elsewhere herein). FIG. 7A is a flow diagram illustrating selected aspects of an embodiment of delay path reduction and minimization, as an example of timing closure. FIG. 7B illustrates a conceptual view of selected elements of an embodiment of timing-driven forces. FIG. 7C illustrates a spatial organization of the driver and the coupled loads of FIG. 7B. FIG. 7D illustrates an embodiment of Net Boundary Box (NBB) estimation of routing to cover the driver and the loads of FIG. 7C. FIG. 7E illustrates an embodiment of a rectilinear Steiner Route Tree (SRT) estimation to cover the driver and loads of FIG. 7C. FIG. 7F illustrates an embodiment of estimated RC parasitics associated with the RST of FIG. 7E. FIGS. 8A and 8B collectively are a flow diagram illustrating selected details of an embodiment of an integrated circuit Electronic Design Automation (EDA) flow using one or more techniques including SDI-directed global placement, legalization, legalization-driven detailed placement, timing optimization, and routing. FIG. 9 illustrates selected details of an embodiment of manufacturing integrated circuits, the circuits being designed in part based on SDI-directed design techniques. FIG. 10 illustrates selected details of an embodiment of a computer system to execute EDA routines to perform SDI-directed place and route operations. FIG. 11 illustrates an embodiment of an SDI-based detailed placement flow. FIGS. 12A and 12B illustrate concepts relating to an embodiment of netlist elaboration. FIG. 13 illustrates an embodiment of detailed placement of a Q-block. FIG. 14 illustrates an embodiment of an additional pass of detailed placement of a Q-block. FIG. 15A illustrates a form of the form-level net of FIG. 12A. In this view the resource-level nodes are shown internal to the form. FIG. 15B illustrates another form that uses different resources to implement the same function as the form of FIG. 15A. In at least one embodiment, the form of FIG. 15B is substituted for the form of FIG. 15A through a morphing process. FIG. 16A illustrates the supply and demand for resources R1 through R6 corresponding to target functions of an integrated circuit design having a first selection of forms for the target functions. For at least some of the resources, the demand exceeds the available supply. FIG. 16B illustrates the supply and demand for resources R1 through R6 for the same target functions, but using a second selection of forms for the target functions obtained by morphing certain forms to use different resources. For each of the resources shown, the demand is less than or equal to the supply. FIG. 17A illustrates an example circuit with a plurality of critical paths. FIG. 17B illustrates example computations relating to an embodiment of CPF scoring. FIG. 18 illustrates an embodiment of a cascade of buffers of increasing drive strength. FIG. 19 illustrates example computations relating to an embodiment of SDF calculation. FIG. 20A illustrates an overall procedural control flow in an illustrative relative slack embodiment. FIG. 20B illustrates the adjustment of timing driven weight in the relative slack embodiment of FIG. 20A. FIG. 21A illustrates a driver in the interior of a net bounding box region. FIG. 21B illustrates a driver to one side of a net bounding box region. FIGS. 22A and 22B illustrate an example circuit excerpt before and after processing according to an embodiment of timing driven buffering and resizing for an array architecture. FIG. 23 illustrates a flow diagram of an integrated circuit design flow including an embodiment of processing in accordance with an embodiment of timing driven buffering and resizing for an array architecture. FIG. 24A illustrates a top-level view of an embodiment of timing driven buffering and resizing for an array architecture. FIG. 24B illustrates a detail view of selected details of an embodiment of timing driven resizing for an array architecture. FIGS. 25A and 25B illustrate an example route tree as processed by an embodiment of segmenting a portion of the route for timing driven buffering and resizing. FIG. 26 illustrates example results of an embodiment of logic replication and tunneling for an array architecture. FIG. 27 illustrates a control flow in an illustrative embodiment, as used for density modification. FIG. 28 illustrates a control flow of an illustrative embodiment, as used to determine the Steiner-cuts congestion term on the SDI grid. FIG. 29 illustrates procedures of an illustrative embodiment, showing creation of a congestion array. FIG. 30 illustrates procedures of an illustrative embodiment, showing calculation of a final congestion density enhancement array. FIG. 31 illustrates an embodiment of a processing flow for node tunneling out of exclusion zones in an SDI-based integrated circuit design flow. FIG. 32 illustrates an embodiment of SDI-related force calculations in a tunneling congestion relief context. FIG. 33 illustrates an embodiment of evaluation of tunneling transition criteria. FIG. 34A illustrates an example clock tree suitable for input to a Clock Tree Synthesis (CTS) tool for Structured Array Fabric (SAF)-based design flows. FIG. 34B illustrates an example clock tree output from the CTS tool operating on the input illustrated in FIG. 34A. FIG. 34C illustrates an example clock tree network. FIG. 35 illustrates an overview of an embodiment of a CTS flow. FIG. 36A illustrates an example die floorplan of a design having embedded Random Access Memory (RAM) or other Intellectual Property (IP) blocks. FIG. 36B illustrates a portion of a clock net in a context of a portion of FIG. 36A. FIG. 37A illustrates an example of timing driven pin swapping. FIG. 37B illustrates an example of effects of clock tree partitioning. FIG. 38 illustrates an analysis according to an embodiment of clock domain and sub-domain partitioning. DETAILED DESCRIPTION A detailed description of one or more embodiments of the invention is provided below along with accompanying figures illustrating selected details of the invention. The invention is described in connection with the embodiments. It is well established that it is neither necessary, practical, or possible to exhaustively describe every embodiment of the invention. Thus the embodiments herein are understood to be merely exemplary, the invention is expressly not limited to or by any or all of the embodiments herein, and the invention encompasses numerous alternatives, modifications and equivalents. To avoid monotony in the exposition, a variety of word labels (including but not limited to: first, last, certain, various, further, other, particular, select, some, and notable) may be applied to separate sets of embodiments; as used herein such labels are expressly not meant to convey quality, or any form of preference or prejudice, but merely to conveniently distinguish among the separate sets. The order of some operations of disclosed processes is alterable within the scope of the invention. Wherever multiple embodiments serve to describe variations in process, method, and/or program instruction features, other embodiments are contemplated that in accordance with a predetermined or a dynamically determined criterion perform static and/or dynamic selection of one of a plurality of modes of operation corresponding respectively to a plurality of the multiple embodiments. Numerous specific details are set forth in the following description to provide a thorough understanding of the invention. These details are provided for the purpose of example and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the invention is not unnecessarily obscured. Introduction This introduction is included only to facilitate the more rapid understanding of the Detailed Description; the invention is not limited to the concepts presented in the introduction (including explicit examples, if any), as the paragraphs of any introduction are necessarily an abridged view of the entire subject and are not meant to be an exhaustive or restrictive description. For example, the introduction that follows provides overview information limited by space and organization to only certain embodiments. There are many other embodiments, including those to which claims will ultimately be drawn, discussed throughout the balance of the specification. As described herein, “dynamic time-evolving SDI” refers to SDI techniques for the modeling and simulation of elements for integrated circuit placement and routing. Dynamic time-evolving SDI includes applying principles of Newtonian mechanics to an “analogy-system” based on a netlist that is a specification of the integrated circuit as part of an EDA flow (such as during physical design development of the integrated circuit). In some usage scenarios the analogy-system (often referred to simply as “system”) includes a single point particle corresponding to each device in the netlist. The system further includes a set of one or more forces acting on each of the particles, in certain embodiments computed as a weighted sum. Various numerical integration techniques are used to apply Newton's second law of motion to the system, forming a time-evolving representation of the system in state-space. In other words a simulation determines paths of the particles in a plane (or three dimensions). Then resultant locations of the point particles are mapped back into resultant placements of the corresponding devices, thus providing SDI-directed placements. Using dynamic time-evolving SDI, elements of the system are pushed simultaneously forward in time through a smooth integration in which the model for the system dynamics is an abstraction utilizing continuous variables and simultaneous exploration. Departures from idealizations of continuous variables and simultaneity are artifacts of techniques for solving the system of coupled simultaneous governing equations, such as that occur with numerical integration on a digital computer. In such digital computer implementations, the departures are limited to specifiable tolerances determined by the quality of result goals and economic considerations (such as available solution time, supply of computing power available, and other similar constraints). The system forces include attractive and spreading components, used to model effects of interconnect, resource usage (such as device area), and to drive various optimizations (such as timing closure). Some of the system forces are directly expressed as functions of the positions of other devices (such as attractive forces between connected devices), some of the forces are indirect functions of the positions of other devices and are computed by way of various fields (such as one or more density fields), and some of the forces that act on some of the devices are independent of the positions of the other devices in the system. Computing selected forces as fields in certain embodiments affords more computational efficiency. SDI-directed placement is useful in various integrated circuit design flows and related implementation architectures, including full custom, semi-custom, standard cell, structured array, and gate array design flows and related implementation architectures. Several variations in the context of structured array design flows enable efficient processing of numerous constraints imposed by the partially predetermined nature of the arrays. A library of composite cells or “morphable-devices” is provided to a synthesis tool (such as Synopsys Design Compiler or any other similar tool). The morphable-devices are used as target logic elements by the synthesis tool to process a netlist (either behavioral or gate-level) provided by a user. A synthesis result is provided as a gate-level netlist (such as a Verilog gate-level netlist) expressed as interconnections of morphable-devices. The synthesis tool assumes the morphable-devices represent the final implementation, subject to device sizing to resolve circuit timing issues. The morphable-devices are, however, subject to additional modifications in the structured array design flow context (see “Structured Arrays”, elsewhere herein), as each morphable-device may be implemented in a plurality of manners using varying resources of the structured array. During phases of resource reconciliation (where attempts are made to satisfy required resources with locally available resources), one or more of the morphable-devices may be transformed to a logically equivalent implementation. For example, an AND function may be implemented by an AND gate, by a NAND gate and an Inverter, or by any other equivalent formulation. Functionally equivalent alternatives are grouped according to implementation function, and individual realizations within a given function are referred to as “forms”. Thus any morphable-device may be implemented as any instance of any form having an equivalent function. Subsequent operations account for variation between logically equivalent forms (such as differences in area, timing behavior, routing resources used or provided, and any other characteristic distinguishing one form from another). Operations relating to interchanging implementations of morphable-devices to satisfy structured array resource limitations and underlying topology, as well as meeting spatial organization constraints, are termed “morphing”. The SDI-directed placement, in various contexts including structured array design flows, includes several phases: global placement, legalization, and detailed placement. Global placement in certain embodiments provides a first-cut location for each morphable-device in a netlist. The first-cut location is subject to additional refinement by subsequent processing (including legalization and detailed placement). Global placement is considered complete when a configuration is attained that is determined to be sufficiently close to legality to proceed to legalization, i.e. the configuration is likely to be reducible to a satisfactory implementation. Legalization starts with the global placement configuration and produces a final configuration in which demand for resources in every region is determined to be no greater than corresponding supply in each region. Detailed placement starts with the legalized placement configuration and assigns every element implementing a morphable-device to specific resources in an implementation (such as a set of specific resource-slots in a structured array architecture). Some simple functions may have degenerate forms requiring only a single resource instance, but more complex forms are composite, requiring more than one physical resource instance plus internal interconnect to correctly implement the function. Various morphing and similar transformation operations may be used in any combination of phases including global placement, legalization, and detailed placement, according to various embodiments. Morphing techniques used in one phase may be distinct or may be substantially similar to morphing techniques used in another phase, varying according to implementation. In some embodiments, different processing phases proceed with morphing operations operating according to respective morphing classes, i.e. a set of morphing classes for global placement, a set of morphing classes for legalization, and set of morphing classes for detailed placement. The morphing classes according to phases may be distinct or may be substantially similar to one another, according to embodiment. SDI-directed placement operations, when applied in a structured array design flow context, may include specialized forces relating to various “morphing classes” representing categories of structured array resources or related functionality. For example, resources for combinational circuitry may be grouped in a combinational morphing class, while resources for sequential circuitry may be grouped in a sequential morphing class. In some situations morphable-devices are restricted to implementation by resources belonging to a limited set of morphing-classes. Continuing with the example, combinational logic morphable-devices may be restricted to implementation by resources of the combinational morphing class, while sequential logic morphable-devices may be restricted to implementation by sequential morphing class elements. One or more specialized forces relating to each of the morphing classes may be used during global placement to effect spreading of morphable-devices according to corresponding morphing classes. Continuing with the example, a combinational spreading force may be selectively applied to combinational logic morphable-devices, while a sequential spreading force may be selectively applied to sequential logic morphable-devices. In certain embodiments, it is useful to subject all devices in the netlist (whether morphable or not) to a single spreading force that acts to drive the circuit toward a density that is sustainable on the implementation architecture, and augment the spreading force with the specialized resource-class-specific spreading forces to further tune the placement. Structured Arrays In some usage scenarios structured arrays are implementation vehicles for the manufacture of integrated circuits, as described elsewhere herein. Structured arrays in certain embodiments include fundamental building blocks (known as “tiles”) instantiated one or more times across an integrated circuit substrate to form a Structured Array Fabric (SAF). In some embodiments structured arrays are homogeneous (i.e. all of the tiles are identical), while in some embodiments the arrays are heterogeneous (i.e. some of the tiles are distinct with respect to each other). Heterogeneity may occur as a result of tile type, arrangement, or other differences. Irregardless of tile number and arrangement, however, the SAF tiles are fixed (i.e. prefabricated) and independent of any specific design implemented thereupon. SAF tiles, according to various embodiments, may include any combination of fully or partially formed active elements (such as transistors, logic gates, sequential elements, and so forth), as well as fully or partially formed passive elements (such as metallization serving as wires and vias providing interconnection between layers of metal). In some SAF embodiments “lower” layers of interconnect are included in SAF tiles (as the lower layers are formed relatively early in fabrication), while “upper” layers of interconnect are specific to a design (as the upper layers are formed relatively later in fabrication). Such SAF embodiments permit the lower prefabricated (and thus non-customizable) layers to be shared between different design implementations, while the higher/customizable layers provide for design-specific specialization or personalization. SAF structures may be used to construct an entire chip, or may constitute only a portion of the floorplan of an encompassing circuit, allowing for design variation. The size of the SAF tiles is generally irrelevant to design flows, and a tile may be as small and simple as a single inverter or as large and complex as a Randomly Accessible read-write Memory (RAM) block or other large-scale Intellectual Property (IP) element. EDA flows targeting designs based on structured array technology (such as the SDI-directed flow described elsewhere herein) account for the predetermined nature of the array, from gate-level netlist synthesis through subsequent implementation processing including layout of cells and interconnect. Such EDA flows enable realizing advantages of manufacture of integrated circuits including SAF tiles. The advantages include reduced manufacturing cost, as fewer mask layers (for example those corresponding to upper layers of interconnect) are customized for each design, as well as reduced characterization cost (for example by re-use of known structures such as the SAF tiles). High-Level Integrated Circuit Physical Design Flow FIG. 1 is a flow diagram illustrating selected details of an embodiment of placing, routing, analyzing, and generating fabrication data for any portion of an integrated circuit according to an SDI-based flow. A representation of all or any portion of the integrated circuit is provided (“Design Description” 120), in certain embodiments including a gate-level netlist, placement constraints, timing requirements, and other associated design specific data. The gate-level netlist may be provided in any proprietary or standard format, or a hardware description language (such as Verilog). A representation of fabrication flow is also provided (“Technology Description” 121), in certain embodiments including information relating to fabrication material starting state and manufacturing flow. The fabrication material information may include data describing wafers and any associated predetermined processing on the wafers (for example fabrication of lower layers of devices). The predetermined processing may be associated with transistors, combinatorial logic gates, sequential logic devices, storage arrays, regular structures, power distribution, clock distribution, routing elements, and other similar portions of active and passive circuitry. The manufacturing flow information may include information relating to physical and electrical design rules and parameters for extraction of parasitic information for analyzing results during physical design flow processing. Flow begins (“Start” 101) and continues (“Pre-Process” 102), where the design and technology descriptions are parsed and various design-specific data structures are created for subsequent use. The design description in certain embodiments includes a gate-level netlist describing interconnections of devices (morphable-devices, according to some embodiments), as well as constraints specific to implementation of the design (such as timing and placement requirements). The technology description includes information such as library definitions, fabrication technology attributes, and descriptions of manufacturing starting material (for example data describing SAF tile arrangement and composition of active and passive elements). Physical locations of some or all of the devices are then determined (“SDI Place & Route” 103), i.e. the design is placed, and wiring according to the netlist is determined (i.e. the design is routed). Place and route processing in certain embodiments includes multiple iterations of one or more internal processes (see “Place and Route Flow”, elsewhere herein). The placed and routed design is then analyzed (“Result Analysis” 104), in certain embodiments with one or more analysis tools performing various functions such as parasitic extraction, timing verification, physical and electrical rule checking, and Layout-Versus-Schematic (LVS) formal verification. Results of the analysis are examined by any combination of automatic (such as software) and manual (such as human inspection) techniques (“OK?” 105). If the results are acceptable, then flow continues (“Yes” 105Y) to produce information to manufacture the design according to the results (“Generate Fabrication Data” 106). The fabrication data varies by embodiment and design flow context, and may include any combination of mask describing data, FPGA switching-block programming data, and FPGA fuse/anti-fuse mapping and programming data. Processing is then complete (“End” 199). If the results are not acceptable, then flow loops back (“No” 105N) to repeat some portion of the place and route operations. In some usage scenarios (not illustrated) one or more modifications to any combination of the design and the technology may be made before repeating some of the place and route operations. For example, synthesis may be repeated (with any combination of changes to functionality as specified by behavioral or gate-level inputs and synthesis commands), a different technology may be chosen (such as a technology having more metal layers), or a different starting material may be selected (such as choosing a “larger” structured array having more SAF tiles). Processing functions (“Pre-Process” 102, “SDI Place & Route” 103, “Result Analysis” 104, “OK?” 105, and “Generate Fabrication Data” 106) are responsive to various instructions and input data (“Commands and Parameters” 130), according to various embodiments. The effects of the commands and parameters on the processing are represented conceptually in the figure (arrows 102C, 103C, 104C, 105C, and 106C, respectively). In various embodiments information is communicated between the processing functions (and other processing elements not illustrated) in various forms and representations, as shown conceptually (“Working Data” 131 and associated arrows 102D, 103D, 104D, and 106D, respectively). The working data may reside in any combination of processor cache, system memory, and non-volatile storage (such as disks), according to implementation and processing phase. The illustrated placement, route, and analysis processing is applied, in various embodiments, to integrated circuits implemented in various design flows or contexts, including application specific, structured array (homogenous and heterogeneous varieties), mask-definable gate array, mask-programmable gate array, Field-Programmable Gate Array (FPGA), and full custom. The processing may be applied to an entire integrated circuit, or one or more portions or sub-sections of an integrated circuit, according to various usage scenarios. For example, an otherwise full custom integrated circuit may include one or more regions of standard cells, and each of the standard cell regions may be processed according to all or portions of the illustration. For another example, an Application Specific Integrated Circuit (ASIC) may include some regions of standard cells and other regions of SAF tiles. Any combination of the standard cell and SAF tile regions may be processed according to all or portions of the illustrated flow. These and all similar variations are contemplated. Place and Route Flow FIG. 2 is a flow diagram illustrating selected details of an embodiment of placing and routing any portion of an integrated circuit, according to an SDI-based flow, such as operations referred to elsewhere herein (“SDI Place & Route” 103, of FIG. 1, for example). Overall the flow includes determining approximate (i.e. subject to subsequent refinement) locations for devices, reconciling resources, determining nearly final locations and implementations for the devices, minimizing critical delay paths, and wiring the devices according to a netlist. In certain embodiments each of the elements of the flow includes internal functions to determine acceptability of results, iterate as necessary to improve the results, and to direct feedback to earlier processing functions of the flow as needed. Processing begins (“Start” 201), in certain embodiments by receiving one or more data structures and files describing a netlist having devices and associated connectivity, along with manufacturing technology information. The structures and files may result from parsing design and technology information (“Pre-Process” 102, of FIG. 1, for example). Approximate locations for the devices of the netlist are then determined (“SDI Global Placement” 202) according to the netlist, the technology, and commands/parameters (such as those from “Commands and Parameters” 130, of FIG. 1). If global placement results are acceptable (i.e. suitable as a starting point for further processing), then flow proceeds (“OK” 202Y). If the global placement results are not acceptable, then flow loops back (“Not OK” 202N, “Repeat” 220, and “Revise” 202R) to repeat all or portions of the global placement. Revised global placement processing (via “Revise” 202R) in certain embodiments includes modifying any combination of the netlist, global placement commands and parameters, and manufacturing technology (such as specifying a larger die, or a denser device fabrication process) based in part upon previous processing. Subsequent to acceptable global placement, resources are reconciled according to the global placement and manufacturing information (“Legalization” 203), resulting in elimination of areas of oversubscribed resources. In certain embodiments modifications are made to the global placement results (effecting “movement” of placed elements) thus producing a legalized placement. If legalization results are acceptable, then flow proceeds (“OK” 203Y). If the legalized placement is not acceptable (or not computed), then flow loops back for additional processing (“Not OK” 203N). In certain embodiments the additional processing is based on previous processing, and may include repeating any portion of global placement (“Revise” 202R via “Repeat” 220) and continuing onward, or repeating any portion of legalization (“Revise” 203R via “Repeat” 220), according to various usage scenarios and embodiments. After acceptable legalization, then nearly final (or “exact”) locations and implementations for the devices are determined (“(SDI) Detailed Placement” 204). Relatively small-scale adjustments are made to legalization results, via any combination of placed element movement and placed element implementation, according to embodiment. In certain structured array embodiments, the placed element implementation includes morphing of selected devices to functionally equivalent alternatives. If detailed placement results are acceptable, then flow proceeds (“OK” 204Y). If the detailed placement is not acceptable (or not computed), then flow loops back for additional processing (“Not OK” 204N). In certain embodiments the additional processing is based in part upon previous processing, and may include repeating any portion of previous place and route functions and then continuing onward (such as via any of “Revise” 204R, “Revise” 203R, and “Revise” 202R by way of “Repeat” 220). Subsequent to detailed placement, delay paths are minimized (“Timing Closure” 205), in certain embodiments to meet user specified timing, in various ways according to embodiment and/or user option or configuration. In certain embodiments the detailed placement is analyzed and buffers (or buffer trees) are inserted in high fanout and timing-critical nets. In some embodiments drivers are resized and optimized to meet maximum capacitance and/or required time constraints with respect to timing critical receivers. In some embodiments clock networks are synthesized, while in other embodiments the clock networks are predefined. In either case the appropriate clock network elements are inserted into the netlist for clock distribution and to meet clock skew constraints. Further according to embodiment and/or user option or configuration, other timing closure driven optimizations are performed (see “Timing Closure”, elsewhere herein). If the timing closure results are acceptable, then flow proceeds (“OK” 205Y). If the timing closure is not acceptable, then flow loops back for additional processing (“Not OK” 205N). The additional processing may include repeating any portion of previous place and route functions, based in part upon previous processing and then continuing onward (such as via any of “Revise” 205R, “Revise” 204R, “Revise” 203R, and “Revise” 202R by way of “Repeat” 220). Note that in some embodiments flow loops back as a natural consequence of timing closure processing, rather than merely as a result of not-acceptable timing closure results. For example, certain timing closure techniques call for repetition of previous processing (such as one or more of “SDI Global Placement” 202, “Legalization” 203, and “(SDI) Detailed Placement” 204), using various combinations of modified behaviors and parameters, along with optional changes to the netlist and constraints, according to various embodiments. After timing closure is complete (or considered “close enough”), the resultant devices are wired together according to the resultant netlist (“Routing” 206), and corresponding interconnect is generated. If the routing results are acceptable, then flow proceeds (“OK” 206Y). Place and route processing is then complete (“End” 299), and results are available for further use, such as any combination of analysis and mask generation (“Generate Fabrication Data” 106 of FIG. 1, for example). If the routing results are not acceptable, then flow loops back for additional processing (“Not OK” 206N). In certain embodiments the additional processing is based in part upon previous processing, and may include repeating any portion of previous place and route functions and then continuing onward (such as via any of “Revise” 206R, “Revise” 205R, “Revise” 204R, “Revise” 203R, and “Revise” 202R by way of “Repeat” 220). Various combinations of place and route processing functions (such as “SDI Global Placement” 202, “Legalization” 203, “(SDI) Detailed Placement” 204, “Timing Closure” 205, and “Routing” 206) may include reading and writing shared information (such as references to “Working Data” 131, of FIG. 1). Examples of working data include netlists, constraints, progress indicators, and other similar shared processing items. Various combinations of the aforementioned place and route processing functions also may include receiving one or more inputs specifying requested behaviors or processing (such as information from “Commands and Parameters” 130, of FIG. 1). Examples of commands and parameters include scripts specifying iteration closure conditions, control parameters, goal descriptions, and other similar information to guide processing. The commands and parameters may be provided via any combination of scripts, command line inputs, and graphical user interfaces, according to various embodiments. In some embodiments processing of one or more elements of FIG. 2 is optional, or performed only for selected iterations though the illustrated flow. For example, timing closure operations may be operative in a first processing mode where legalization and detailed placement are skipped, and processing relating to timing closure is partially performed as part of global placement. Alternatively the first processing mode may be viewed as global placement operations being performed to a limited extent, then analyzed and further directed by timing closure operations (without legalization or direct placement), and then additional global placement operations being performed. Eventually a second mode of processing may be entered where legalization and detailed placement are performed, optionally followed by additional timing closure operating as in the first mode or operating in a manner specifically tailored to the second mode (see “Timing Closure”, elsewhere herein). Simultaneous Dynamical Integration (SDI) Directed Global Placement Conceptually SDI may be understood as modeling each individual device of the netlist as a node, or point particle, having an associated mass, position (or location), and velocity. The nodes representing the devices of the netlist are coupled by and interact with each other via attractive and spreading forces. The forces may include attractive forces representing electrical connections between the devices (as specified by the netlist), and spreading forces modeling resource requirements versus availability (such as a density of logic gates needed versus a density of logic gates on hand). The nodes and effects of the coupling forces are simulated as evolving over time as governed by a system of coupled ordinary differential equations using continuous variables, according to classical Newtonian mechanics (i.e. force equals mass multiplied by acceleration, or F=ma). Thus locations of nodes (corresponding to device placements) evolve over time from initial positions to subsequent positions (corresponding eventually to the global placement result for the devices). More specifically, the independent variables in the dynamical system simulation include configuration-space variables (position and velocity) of the nodes. In certain embodiments the position and velocity representations are multi-dimensional quantities (two or three dimensions, for example), according to usage scenario and embodiment. Force terms in the coupled equations of motion are related to any combination of the topology of the connections of the devices, timing analysis of evolving device locations (placement), obstructions, and region constraints (fixed and floating), according to embodiment. Force terms may also be related to any combination of partial node density, partial resource usage density, viscous damping, energetic pumping, interconnect congestion effect modeling, power or clock distribution, and signal integrity representation, according to embodiment. Force terms may include any function of the independent variables, provided commands and parameters, and other similar mathematical devices useful in managing numerical behavior of continuous time integration of the system of nodes and forces. In certain embodiments the obstructions are represented as exclusion zones, and arise as a result of architectural considerations, location-fixed (or predetermined) blocks (such as large RAM arrays or IP elements), and other similar placement limiting conditions. In certain embodiments the region constraints are represented as fixed, relative, or floating location requirements on selected devices of the netlist. Corresponding position requirements (such as an initial position with no subsequent change during system simulation time) are imposed for the corresponding nodes in the dynamical simulation. Various combinations of region constraints (relating to integrated circuit floorplan specifications, for example) may be developed by any combination of automatic techniques (by software, for example) and manual techniques (by users), according to usage scenarios and embodiments. Conceptually the system of coupled simultaneous differential equations is operational in continuous variables. While it is envisioned that certain embodiments will perform at least some of the integration according to true analog integration techniques, in which the state variables are actually continuous, in digital computer embodiments, the integration is performed using digital integration techniques. Digital computers are limited to representing all quanta with finite-precision variables and that continuous time integration may be implemented on digital computers using “pseudo-continuous” numerical approximation techniques, a.k.a. “numerical methods.” Even when implemented using finite-precision approximations, the “continuous variables” abstraction is a useful way to conceive and describe some of the techniques described herein and to distinguish compared to other approaches using conceptually discrete variables. Thus the term continuous as used throughout this disclosure should be interpreted in accordance with the foregoing. In digital computer embodiments, continuous state variables (including those variables representing simulation time, mass, location, and velocity) are approximated as any combination of single, double, or extended floating-point numbers. The continuous time integration of the simultaneous coupled dynamical governing equations may be performed in digital computer embodiments by any suitable digital integration technique, such as Runge-Kutta, predictor-corrector, leap-frog, and any similar technique adaptable to continuous multi-variable state space integration. In some embodiments the integration technique is chosen for suitability based at least in part on adaptability to parallel processing (see “Computer System Executing SDI-Directed EDA Routines”, elsewhere herein). The forces acting in the system provide coupling between the nodes and act to accelerate the nodes over time, resulting in movement of the nodes throughout the state-space over time. A set of attractive forces (known as “net attractive forces”) is modeled to represent connectivity between the devices of the netlist, or more specifically between pins (i.e. terminals of circuit elements) of devices. In some embodiments the net attractive forces are modeled as individual springs between a pin of one device and a pin of another device, with every interconnection between any two pins being modeled as a corresponding spring. Force associated with each spring is computed according to Hooke's law (force is proportional to distance between the pins). The net attractive force acting on each device is a vector sum of all net attractive forces acting on all of the pins of the respective device. In some embodiments the constant of proportionality used to calculate spring force is identical for all springs. In some embodiments the constant of proportionality is dependent on the fanout of a net (i.e. the number of pins connected together). In some embodiments relatively high fanout nets are considered to be one or more drivers providing a signal to one or more loads. Springs between the loads of the relatively high fanout nets are eliminated (while springs from drivers to loads are retained). In some embodiments springs between drivers and loads have a different constant of proportionality than other springs. Modeling of net attractive forces is not restricted to ideal springs, and may instead be based on a general linear or non-linear force model, according to various embodiments. A set of spreading forces (known as “spatial spreading forces”) is modeled based on one or more macroscopic density fields. In certain embodiments the density fields are computed based on analysis of metrics associated with respective devices corresponding to the nodes (and their locations) in the dynamical system. The metrics may include any combination of standard cell area (in, for example, standard cell flow processing), fabric resource consumption (in, for example, SAF flow processing), equivalent gate count, and other similar functions of node properties. In some embodiments the spatial spreading forces (see “Field-Based Force Components”, elsewhere herein) are with respect to a density field based on resource utilization of corresponding nodes in a local region. In some embodiments resource utilization may be evaluated using an area averaging or summation of nearby devices or an equivalent-gate count rating (cost function) of spatially close devices. In some embodiments a plurality of density fields are computed with respect to a plurality of metrics. In some embodiments any combination of first, second, and third density fields are computed with respect to first, second, and third categories of logic devices (such as combinational logic devices, sequential logic devices, and total logic devices). In some embodiments each of a plurality of partial density fields is computed according to a set of respective non-interchangeable morphing classes (such as combinational and sequential morphing classes) associated with an underlying SAF. In some embodiments (such as selected standard cell based design flows) the density fields are computed based wholly or partially on device area. In some embodiments (such as selected structured array based design flows) the density fields are computed based wholly or partially on resource utilization as measured by counts of the number of each type of resource needed to implement the function associated with each device in the netlist. Other attractive and spreading forces may also be included, according to usage scenario and embodiment. Floorplan constraints, or various region constraints, may be expressed as attractive or spreading forces, or as potential wells (with a tendency to retain nodes in a region) or potential barriers (with a tendency to disperse nodes from a region), according to usage scenario and embodiment. For example, boundaries of a die, or locations of input/output (IO) rings may be expressed as fixed constraints that are mapped to attractive forces acting on nodes having interconnect to the IO ring. For another example, a selected region of the die may be excluded from use (such as for yield improvement or noise reduction) by fixed or relative (i.e. floating) constraints that are mapped to spreading forces acting on nearby or all nodes (see “Exclusion Zones”, elsewhere herein). In other embodiments or modes of operation, such floorplan constraints may be implemented through coordinate clipping inside the integrator, thereby preventing the motion of devices into disallowed regions. User specified circuit timing constraints may warrant that certain pins in the netlist be moved closer together to improve the performance of the design. A corresponding set of attractive forces between drivers and select loads is fed into the system as attractive forces with configurable binding strength. Viscous Damping Forces other than attractive and spreading forces between nodes or other elements may also be accounted for. As an example, a viscous damping force may be included as a way to (a) compensate for the effect of numerical errors (potentially incurred by the time integration and spatial differencing techniques used) contributing toward numerical heating, and (b) change the ratio between kinetic and potential energy of the node distribution. The damping serves to decelerate the ballistic motion of a node. One embodiment of such a force on a given node is a term proportional to the negative of the node velocity, with the proportionality constant being equal to μ, the global coefficient of viscosity. The value of μ may be supplied by direct manual input (by a user) or via automatic control, (under software control) according to embodiment, to provide partial control of the node distribution as a whole. While μ is a global constant, it may have a local effect, and thus in some embodiments other parameters are selected for manipulation to provide control of the node distribution as a whole. For example, in some implementations a ratio of KE/TE, where KE is the kinetic energy of the node distribution and TE is the total energy of the system, is a convenient control parameter. In some embodiments, the global viscosity coefficient is split into two terms, a gradually drifting term and a dynamically calculated term. The gradually drifting term enables the system to gradually adapt to time varying forces or parameter changes, while the dynamical term prevents runaway acceleration on a per-timestep basis. Each timestep the total effective μ is adjusted in response to normalized kinetic energy (KE/TE) changes from a selected target value. In certain embodiments the adjustment to R is given by: If KE/TE>target then: dm=cdm1*((KE/TE/target)−1)+cdm2*((KE/TE/target)−10)ˆ2 μ—eff=μ*(1+dm) μ=(1+<small adjustment>) If KE/TE<target then: dm=cdm1*((target/KE/TE)−1)+cdm2*((target/KE/TE)−10)ˆ2 μ—eff=μ/(1+dm) μ/=(1+<small adjustment>) where: double mu_max=1.e+8; double cdm1=1.; double cdm2=0.01; and Note that “double” refers to double-precision variables used in some embodiments. The <small adjustment> may vary with the relative difference between the target and actual values of KE/TE, and tends to be small compared to 1. The term “mu_max” limits μ to prevent numerical problems with a timestepper used for numerical integration. The quadratic term contributes little until KE/TE differs from the target by a factor of 10, and quenches runaway conditions. By splitting the calculation of μ into a purely dynamical term and a slowly varying term, the system remains generally stable while retaining an ability to react quickly to energy spikes. Further, by using a constant μ during the course of the time integration, performance may be enhanced, as operation counts are substantially reduced and adaptive integrator timesteps (if relevant) may be allowed to increase. In some embodiments a viscous damping proportionality constant is identical for all nodes in the system, while in other embodiments one or more distinct proportionality constants may be employed. For example, in certain embodiments the viscous damping proportionality constant is modeled as a scalar field of position and the value of the constant at the position of each circuit device is computed. Moreover, in certain embodiments the scalar field is analytically specified, and selectively includes a dependence upon the independent time variable. In other embodiments the scalar field is a derived quantity computed from other numerical characteristics that may be evaluated for the time-evolving simulation. Additionally, the viscous force is not limited to being proportional to the velocity of a node. In certain embodiments the viscous force instead follows a functional form based on other selected state of the system. The aforementioned forces are merely representative examples. Forcing terms may be associated with interactions between one or more nodes, and between one or more fixed (or immovable) elements. Forcing terms may also be associated with fields that may be dependent in some way upon one or more nodes, or with fields that are independent of nodes. These and all similar types of forcing terms are contemplated in various embodiments. Thus forces on the nodes of the system include direct interactions with topological neighbors (according to the netlist), collective interactions involving numerical constructs associated with temporal bulk properties of the node distribution, and with architectural features of the implementation. The result of the combination forces impinging on the system nodes is a complex dynamical interaction where individual nodes meander through the placement domain under the influence of the forces and wherein the forces vary continuously with the motion of all nodes in the netlist. The motion exhibits both chaotic and coherent behaviors. The motion of a given node may appear chaotic in the sense that the node trajectory may meander back and forth as a result of connections to other nodes. Yet the system may also exhibit coherent (or collective) motion in the sense that tightly connected nodes will tend to move in bulk and remain in proximity to topological neighbors even as the tightly connected nodes collectively move far from respective starting points. The integration of the governing equations of motion proceeds using standard techniques of numerical integration. (See for example, a reference describing numerical integration.) As an example, the next several paragraphs assume the use of a Runge-Kutta integrator. The computation of the forcing terms is referred to as “computing the derivatives”. Differentiation is denoted with respect to time by ′ (prime), so that dx/dt=x′, d2x/dt2=x″, and so forth. The following variables are introduced to set up the governing equations for solution by numerical integration: vx,i=(xi)′ vy,i=(yi)′ The subset of the system of equations relating to the ith node (for a two-dimensional layout application) is: (xi)′=vx,i (yi)′=vy,i (vx,i)′=Fx,i (vy,i)′=Fy,i Thus the system of simultaneous second order differential equations is transformed to a (larger) system of simultaneous first order differential equations, where the right hand side of each equation is the derivative of the respective left hand side. Conceptually computation of a derivative per se is not required (unless some element of the forcing terms is itself expressed as a derivative of something else), but rather the right hand sides of the equations are the derivatives. There is time-varying complexity in the behavior (character of motion) of the moveable nodes in the netlist when the forcing terms are time varying. In some embodiments a time varying timestep is used to preserve numerical accuracy and to continue processing until convergence criteria (error limits) are met during each timestep in the integration. The integrator accepts as input a specification of a desired timestep, and then processes the timestep in two ways: once directly, and once as two half-steps. If the results are not close enough as determined by a specifiable error-norm, then the target timestep is reduced until it is possible to perform the one-step plus the two-half-steps approaches with results within an error norm. Besides new coordinate values for the independent variables, the integrator also returns the length of the timestep just taken and the advised length for the next timestep. Thus during periods of laminar motion when numerical convergence is readily achieved, the timestep trends longer on successive calls to the integrator. But in periods of turbulent or chaotic motion, where convergence requires more effort, the timesteps become as small as needed to ensure the accuracy of the integration. FIG. 3A is a flow diagram illustrating selected details of an embodiment of global placement according to SDI modeling and simulation, such as operations referred to elsewhere herein (“SDI Global Placement” 202, of FIG. 2, for example). Overall the flow includes various functions to enable and perform a series of dynamical simulations based on Newtonian mechanics on a system representing the netlist and associated design constraints and targets. The simulations use SDI techniques to orchestrate the interactions between particles (representing netlist devices). The SDI techniques make use of fields that are calculated as functions of the particle positions. The functions include determining a set of nodes corresponding to the devices in the netlist, initialization of state variables (including mass, location, and velocity associated with each node), adjusting forces, and evolving the resultant system of simultaneous dynamical governing equations forward in time via integration. The flow is repeated beginning at the adjustment processing until a suitable result is available, or it is determined that a suitable result will not become available without further processing outside of the illustrated flow. Processing begins (“Start” 301) with receipt of pre-processed information, in certain embodiments as data structures representing the netlist and the associated devices and connectivity (“Pre-Process” 102, of FIG. 1, for example). Further data structures for representing a system of nodes and forces are created and initialized (“Determine Nodes and Forces” 302), with each node in the system corresponding one-to-one with each device of the netlist, and with each node having a corresponding set of forces acting on it. State variables for the dynamical simulation are initialized (“Initialize State Variables” 303), including determining starting values for mass, location, and velocity state variables for each node. The initial node locations correspond to initial placements of the corresponding netlist devices (see “Initial Placement”, elsewhere herein). Initial force values are also determined. Large-scale goal-driven modifications to the forces in the system are then made (“Macro Adjust Forces” 304). In some embodiments one or more attractive forces are over- or under-weighted for periods of time, and one or more spreading forces may also be reduced or increased in relative proportion to the attractive forces. For example, a “condensing” phase may inflate attractive forces and deflate spreading forces, and an “extending” phase may deflate attractive forces and inflate spreading forces. Operations associated with the macroscopic force adjustment track simulation time and change the forces according to condensing and extending phases. During the phases of system evolution, the coordinates of individual nodes continue to evolve separately based on the governing equations for each individual node. Consequently, the behavior of any individual node may vary from the bulk behavior of the collective system. Other large-scale force adjustments may also be made, according to embodiment, including entirely removing one or more forces for a period of simulation time, and introducing a new force. The removal (or introduction) of a force may be at a predetermined point in simulation time, at a point in simulation time determined by computation of a test condition, any similar mechanism, and/or at the discretion of a human operator of the system, according to various embodiments. In certain embodiments the removal (or introduction) of a force is gradual, and the rate of change of the removal (or introduction) may vary over simulation time or be constant, according to implementation. In some embodiments the macroscopic force adjustments are in response to various force-control instructions and input data (such as represented conceptually by “Commands and Parameters” 130, of FIG. 1). Large-scale goal-driven modifications to the effects of masses in the system are then made (“Macro Adjust Masses” 305). In certain embodiments the effects of masses are modified during phases where node densities are being adjusted to more evenly distribute resource consumption, or to more evenly match resources needed with resources available. For example, in usage scenarios including global placement of devices according to SAF tiles, macroscopic mass adjustments may be made to “encourage” cells in over-subscribed regions to “move” to less subscribed regions (see “Depletion Weighting”, located elsewhere herein). As in the case of macroscopic force adjustments, macroscopic mass adjustments may be varied according to simulation time phase, and may be gradually introduced (or removed) over the course of system evolution throughout simulation time. In some embodiments the macroscopic mass effect adjustments are in response to various mass-control instructions and input data (such as represented conceptually by “Commands and Parameters” 130, of FIG. 1). Note that adjusting the effects of mass, in certain embodiments, is with respect to densities and forces brought about by the masses, while the momentum of each of the nodes having adjusted mass effects remains unchanged. A dynamical simulation of the nodes (as point particles) according to the mass, location, velocity, force, and other state variables is performed (“SDI Simulation” 306) for some amount of system simulation time. The time may be a predetermined interval, dependent on specific completion criteria (as provided to the SDI simulation), and any similar interval specification scheme, according to various embodiments. At the end of the simulation time the system arrives at a new state. In certain embodiments the new state includes new locations for one or more of the nodes, and the new locations of the nodes are interpreted as corresponding to new locations for the devices being placed. According to various embodiments, any combination of the system variables (including simulation time and node mass, location, and velocity) and corresponding interpretations of the system variables in the context of the netlist (including device location and density) are examined to determine if portions of the flow should be repeated (“Repeat?” 307) or if flow is complete (“OK Result?” 308). If repeating the flow would likely improve results, and no other end condition has been met, then flow loops back (“Yes” 307Y) to macro adjustment of selected forces and masses. In some embodiments configurable settings are adjusted prior to or in conjunction with force and mass macro adjustments (such as settings associated with “Commands and Parameters” 130, of FIG. 1). If the global placement is close enough (“No” 307N), then flow is complete (“OK” 202Y) and processing continues to legalization (see FIG. 2). If there would likely be no benefit in iterating the global placement (“No” 307N), and the results are not acceptable, then flow is also complete (“Not OK” 202N), but subsequent processing then includes one or more revisions (see FIG. 2). Tests to determine if the flow is to be repeated may be made for a predetermined end condition, a predetermined rate of change, other similar criteria, and any combination thereof according to assorted implementations. In some embodiments the flow is not repeated even if improvement is likely possible (for example if an interval of simulation time has expired). Determinations (“Repeat?” 307 and “OK Result?” 308) are according to any combination of automatic (software program) and manual (human user) techniques, according to various embodiments. For example, an automatic technique may include software determining if the most recent iteration is a significant improvement over a previous iteration. If so, then repeating the flow is beneficial. As another example, a manual technique may include a user observing the time-evolving locations of devices and noticing that further improvements are possible and that repeating the flow would be beneficial. Another manual technique may include a user determining that the placement as changing over time is “stuck”, perhaps due to some incorrectly specified constraints, and that additional iterations of the global placement flow are not likely to be beneficial unless modifications are made to the constraints. Any portion (or all) of global placement may be performed according to various techniques, in addition to the aforementioned SDI directed technique. The additional techniques include simulated annealing, objective minimization techniques such as conjugate-gradient, chaotic processing, and other similar mechanisms to provide approximate or “close enough” device coordinates, according to various embodiments. Initial Placement FIG. 3B is a flow diagram illustrating selected details of an embodiment of initial placement operations for global placement, such as selected operations performed while initializing state variables (as in “Initialize State Variables” 303 of FIG. 3A). Processing begins (“Start” 310) and then one of a plurality of starting location definition techniques is chosen (“Select Technique” 310A), based, in some embodiments, on instructions provided by a user (such as information from “Commands and Parameters” 130, of FIG. 1). A first technique determines an initial placement based on a placement performed in the past (“Prior Solution” 311). A second technique formulates an initial placement based on randomization (“Random” 312). A third technique develops an initial placement according to any of a number of other mechanisms (“Selected Algorithm” 313), chosen by any combination of software and user input. The chosen technique is then performed and processing is complete (“End” 314). Mass Determination In some embodiments, determination of mass (as in “Determine Nodes and Forces” 302, for example) is dependent on the design flow or implementation context (such as application specific, structured array, mask-definable gate array, mask-programmable gate array, FPGA, and full custom). For example, in a standard cell context, the mass of a node may be computed as a function (such as a linear function) of area occupied by the corresponding device in the netlist. For another example, in a structured array context, the mass of a node may be computed with respect to consumption of resources provided by the structured array, or with respect to local availability or scarcity of the resources, according to the corresponding device as implemented by the resources. For another example, in an FPGA context, the mass of a node may be computed according to consumption of Look Up Table (LUT) resources, or similar switching and/or routing resources. In some embodiments the spatial spreading forces (see “Field-Based Force Components”, located elsewhere herein) are with respect to a density field based on resource utilization (such as an area averaging or summation of nearby devices or an equivalent-gate count cost function of spatially close devices) of corresponding nodes in a local region. In some embodiments first and second density fields are computed with respect to first and second categories of logic devices (such as combinational logic devices and sequential logic devices). Field-Based Force Components In some embodiments various elements of the spatial spreading forces are with respect to one or more resource usage based density fields, or other types of density fields. The density fields are managed independently, and may include any combination of all nodes, combinational nodes, and sequential nodes. Computation of density fields and resultant spreading forces conceptually includes calculating local densities according to a discrete grid, computing density fields, allocating field strengths according to the discrete grid to system nodes, and calculating resultant spatial spreading forces acting on the system nodes. In some embodiments the discrete grid is a uniform (or non-variable) grid, and in some embodiments the grid is a non-uniform (or variable) grid, the grid being implemented according to architectural considerations. Local density calculation includes summing resource usage computed in continuous spatial variables (i.e. node location and mass) according to the discrete grid and digitally filtering the resultant gridded scalar field. The local density calculation includes special accounting for edges of the grid. The digital filter result is suitable for processing by a field solver. Density field computation performed by the field solver includes determining density fields (given density values on the grid) and digitally filtering the result. Allocating field strengths includes interpolating field strengths to nodes (in continuous location space) while accounting for edges of the grid. Repulsive (or spreading) forces are then computed according to the allocated field strengths. In some embodiments the grid is a unit grid, and the region enclosed by adjacent grid lines is termed a “cell”. The grid may be two-dimensional (i.e. x and y) or the grid may be three-dimensional (i.e. x, y, and z), according to implementation technology and other design-flow related parameters. In some embodiments resource usage density is proportional to the respective mass of each node, and the mass is in turn directly proportional to a “gate rating” that is a measure of relative cost of implementing a logic function corresponding to the node. In some embodiments the gate rating of the node is measured in “gate-equivalents” commonly associated with design-flow device selection criteria. FIG. 3C is a flow diagram illustrating selected details of an embodiment of density field based force component computation, in a specific context of resource usage densities expressed in certain embodiments as mass that is proportional to gate rating. The operations of the flow are performed for each of a possible plurality of density fields, each field having separate accounting. Flow begins (“Start” 330), and proceeds to determine local resource usage density by accumulating system node masses with respect to a scalar field organized as a regular grid (in the illustrated embodiment) according to the SDI simulation spatial field (“Accumulate Gate Densities” 331). The grid is finite in size, completely covering space in the system simulation corresponding to the area available for the devices of the netlist (either an entire die or a portion thereof). The grid is extended, via one or more guard grid locations (or grid cells) one or more units around each border of the area (the boundaries of the area) to more accurately and efficiently model edge effects. The guard grid elements are then included in the gate density calculation (“Fold Guard Cell Contributions” 332). The single-unit guard-cell buffer is used in some embodiments employing two and three-point allocation/interpolation schemes, and a multi-unit guard-cell buffer is used in some embodiments having higher order allocation schemes. The resultant density values are then further optionally processed (“Digitally Filter Density” 333), according to embodiment, to smooth variations caused by grid element representation inaccuracies. Density values for guard grid elements are then determined (“Calculate Density Guard Cell Values” 334) to enable straightforward and efficient field solver implementations. Density field computations (“Solve Gate Fields” 335) are then performed by the field solver, determining the field value at each point as equal to minus the gradient at the point (i.e. field=−Grad(n)). Any field solution technique applicable to calculating a derivative with respect to a discrete grid may be used, such as a second order finite difference formula, or any other suitable technique, according to embodiment. In some embodiments the second order finite difference formula is given as the derivative at grid point “i”, and is equal to one-half the quantity equal to the difference of the values at adjacent grid points along one of the orthogonal dimensions (i.e. field(i)=(density(i+1)−density(i−1))/2). Derivatives are calculated for each orthogonal dimension of the system node space (two or three dimensions, according to embodiment). The result is a gridded vector field for each gridded density (such as all, combinational, and sequential). In some embodiments vector field values are stored in a data structure as a tuple. Each member of the tuple corresponds to a value associated with an orthogonal dimension of the vector field, and there is a tuple associated with each grid point. In some embodiments vector field values are stored separately as scalar fields, according to each vector field orthogonal component. Each respective scalar field represents all grid points. In some embodiments vector field values are stored according to other arrangements that are mathematically equivalent to tuples or scalar fields. In addition, vector fields may be stored in various combinations of tuple, scalar field, and other forms, according to embodiment. The representation employed for the vector fields may also change during processing to enable more efficient computations. Further, during processing, any portion of vector field representations may be stored in any combination of processor cache memory (or memories), processor main memory (or memories), and disk (or other similar non-volatile long-term) storage, according to usage scenario and implementation. The gridded vector fields are then processed according to a digital filter (“Digitally Filter Fields” 336). In some embodiments the filtering of the gridded vector fields is according to operations identical, except for edge processing, to the smoothing performed on density values (as in “Digitally Filter Density” 333). The difference between the filter operations is that for density filtering even parity is used when processing the boundaries, while for field filtering even parity is used for field components parallel to the boundary and odd parity is used for field components perpendicular to the boundary. The difference in parity accounts for the differentiation operation performed between density and field domains, such that parity is reversed from even (for density) to odd (for field) when differentiation is directed into a boundary. For a (scalar) density, even parity means values associated with guard grid points are added to interior grid points. For a (vector) field, even parity means the guard grid points are equal to respective closest inner grid points for, and odd parity means that the guard grid points are equal to the negative of respective closest inner grid points (“Calculate Field Guard Cell Values” 337). Thus the average field directed into (or out of) a boundary vanishes at the boundary. Assigning guard point field values enables subsequent efficient computation of field values in the continuous location representation of nodes from the discrete field values (“Interpolate Gate Fields to Nodes” 338). Corresponding forces may then be calculated according to node field values and node masses. Processing is then complete (“End” 339). FIG. 3D is a flow diagram illustrating selected details of an embodiment of gate density accumulation, such as operations referred to elsewhere herein (“Accumulate Gate Densities” 331, of FIG. 3C, for example). Conceptually mass associated with each node (represented in continuous location space) is allocated to a local neighborhood portion of the discrete grid points. Guard grid points are added around the boundary of the grid to efficiently process edge conditions. In some embodiments a two-point linear spline, also known as a Cloud-In-Cell (CIC) or area weighting technique, is used to allocate the mass of each node to four neighboring grid points. In some embodiments a three-point spline technique is used to allocate node mass to nine neighboring grid points. More specifically, flow begins (“Start” 340) by initializing accumulation variables (such as to zero), and then a check is made to determine if processing is complete for all nodes in the simulated system (“Iterated Over All Nodes?” 341). If so, (“Yes” 341Y), then gate field interpolation processing is complete (“End” 345). If not, then a first (and subsequently a next) node is selected for processing, and flow continues (“No” 341N). Spline coefficients are then determined for the node (“Determine Spline Weights” 342), based on distances from the respective node to each field grid point (see the discussion of FIG. 3E, elsewhere herein). After all of the spline weights for all of the grid points have been calculated, a check is made to determine if all fields the respective node contributes to have been processed (“Iterated Over all Fields” 343). If so (“Yes” 343Y), then processing loops back to check if all nodes have been processed. If not, then a first (and subsequently a next) field is selected for processing, and flow continues (“No” 343N). The effect of the node is then accumulated to the respective field array at each of the grid points currently subject to interpolation (“Apply Node Weight to Field Array” 344). Processing then loops back to determine if all fields have been processed. FIG. 3E is a conceptual diagram illustrating an embodiment of two-point interpolation of node mass to grid points, as performed during mass accumulation (such as “Determine Spline Weights” 342, of FIG. 3D). Boundary 394 is shown to represent edges of the system simulation space (and corresponding edges of an integrated circuit region or die). Several points of the discrete grid are illustrated: interior point I1 381, boundary points B1 371, B2 372, and B3 373, and guard points G1 386, G2 388, and G3 389. Mass from node N1 375 is shown accumulating to four grid points (G1, G2, G3, and B2), according to distance along orthogonal dimensions of the system simulation location space (δx1 390 and δy1 392). Conceptually grid points B2 and G1 together receive (1−δx1) of the mass of N1, while grid points G2 and G3 together receive δx1 of the mass of N1. More specifically each dimension is processed in a geometric fashion, so the total mass contribution from N1 to B2, for example, is (1−δx1)*(1−δy1), and so forth. As illustrated in the figure, δx1 is the projected distance along the x-axis from B2 to N1, and similarly for δy1 with respect to the y-axis, B2, and N1. The figure also illustrates mass allocation of node N2 376 to four neighboring grid points (B1, B2, B3, and I1), none of which are guard points. The mass contribution from N2 to point B2 is additive with the mass contribution from N1 to B2. Also, there may be any number of other nodes (not illustrated) within the same grid cell as either of nodes N2 and N1, and masses from the respective nodes are accumulated in the same manner as illustrated for N2 and N1. FIG. 3F is a conceptual diagram illustrating an embodiment of three-point interpolation of node mass to grid points, as performed during mass accumulation (such as “Determine Spline Weights” 342, of FIG. 3D). The figure is representative of operations similar to FIG. 3E, except the node being processed according to mass accumulation affects masses accumulating for nine nearest-neighbor grid points (B0 370, B1 371, B2 372, B3 373, B4 374, I4 384, I3 383, I2 382, and I1 381). The formula representing accumulation to a point (such as I1) is implementation dependent. FIG. 3G is a conceptual diagram illustrating an embodiment of applying guard grid point masses to interior grid points, such as operations referred to elsewhere herein (“Fold Guard Cell Contributions” 332 of FIG. 3C, for example). The elements and representations are similar to FIG. 3E. In a first stage of processing, contributions of “right-hand column” guard elements (G2 388, G3 389, and G4 390) are summed, or “folded” into corresponding guard and interior elements of the adjacent column (G1 386, B2 372, and B3 373, respectively), as suggested conceptually by curved arrows 396. In a second stage of processing, contributions of “top row” guard elements (G1 386 and G0 385) are summed to (or folded into) corresponding interior elements of the adjacent row (B1 371 and B2 372, respectively), as suggested conceptually by curved arrows 395. The summation processing corresponds to even parity. Similar processing is performed for the other two edges of the region. FIG. 3H is a flow diagram illustrating selected details of an embodiment of digital density filtering, such as operations referred to elsewhere herein (“Digitally Filter Density” 333, of FIG. 3C, for example). Conceptually each density grid is filtered, alone or in combination with other density grids, according to embodiment. Filtering each density grid may include filtering all of the elements of the respective grid, although in certain embodiments filtered elements may be selected. Applying the digital density filtering process includes determining edge conditions for each grid element, “smoothing” temporary copies of elements of the grid, and replacing the original grid elements with the smoothed elements. More specifically, flow begins (“Start” 350) and a working copy of grid elements is created. Then additional elements are added “outside” the spatial boundaries of the temporary grid (“Populate Guard Cells” 351). The added guard elements enable more useful smoothing results in some usage scenarios. Then a local averaging is performed on elements of the temporary grid, including the guard elements (“Apply Spreading Function” 352). In some implementations the spreading function reduces numerical artifacts associated with short-wavelength density fluctuations. In some usage scenarios the numerical artifacts arise due to inaccuracies in representation of a grid or grid elements. Any combination of smoothing functions may be used, according to various embodiments, including relatively conservative and relatively more aggressive techniques. In some embodiments a binomial weighting function implementing a 1-2-1 spreading (with a subsequent division by four to preserve total mass) over spatially neighboring grid element values is used. In some embodiments the binomial weighting is performed in any number of orthogonal dimensions, up to and including the maximum number of spatial dimensions represented in the SDI simulation. After completing the spreading processing, the temporary elements are used to replace the original array elements (“Copy to Original Array” 353) and flow is complete (“End” 354). In some embodiments all of the filtering operations for all of the elements of all of density grids are completed before any of the associated temporary results replace the original elements, as the original elements are required as inputs to respective filtering computations for each grid. Alternatively, temporary copies of all of the original elements may be made, and the copying may occur as filtering result are made available. Other similar arrangements of original and temporary element management with respect to filtering computations are envisioned. As mentioned elsewhere herein, processing according to the illustrated flow is entirely optional, according to embodiment. In addition, in some embodiments multiple iterations of the flow may be performed, in some usage scenarios using varying filter functions. Consequently zero or more iterations of the illustrated flow are performed (the iterations are not explicitly shown), according to application requirements and implementation. FIG. 3I is a flow diagram illustrating selected details of an embodiment of interpolating gate fields to nodes, such as operations referred to elsewhere herein (“Interpolate Gate Fields to Nodes” 338, of FIG. 3C, for example). Conceptually field components calculated according to the (discrete) grid are mapped onto the continuous spatial coordinates of node locations. In some embodiments the mapping is according to the node mass accumulation (such as summations performed in “Accumulate Gate Densities” 331). In other words, if an N-point spline technique is used to accumulate densities, then an N-point spline technique is also used to interpolate fields to nodes, and the value of N is the same for both techniques. Using matched spline weights during accumulation and interpolation prevents “self-forces” that would otherwise arise and spontaneously propel a node inconsistently with forces acting on the node. More specifically, flow begins (“Start” 360) by initializing node force values (such as to zero), and then a check is made as to whether processing is complete for all nodes in the simulated system (“Iterated Over All Nodes?” 361). If so, (“Yes” 361Y), then gate field interpolation processing is complete (“End” 365). If not, then a first (and subsequently a next) node is selected for processing, and flow continues (“No” 361N). Spline coefficients are then determined for the node (“Determine Spline Weights” 362), based in part on user input in some embodiments (such as those from “Commands and Parameters” 130, of FIG. 1). In some embodiments the user input is chosen to drive balancing corresponding device distribution throughout an integrated circuit die. After all the spline weights for the respective node have been determined, a check is made to determine if all fields affecting the respective node have been processed (“Iterated Over all Fields” 363). If so (“Yes” 363Y), then processing loops back to check if all nodes have been processed. If not, then a first (and subsequently a next) field is selected for processing, and flow continues (“No” 363N). The force contributed according to the respective field is accumulated with forces associated with other fields (“Sum Field Contributions to Force on Node” 364). The accumulation is according to each orthogonal spatial dimension associated with force modeling (i.e. x and y for two-dimensional systems and x, y, and z for three-dimensional systems). Flow then loops back to determine if all fields have been processed. Depletion Weighting The effect a node has on local density and resultant forces may be “artificially” increased (or decreased) to expedite nodes moving to more satisfactory placements more quickly. Local density modification may be considered to be a result of manipulating a weighting associated with the mass of one or more nodes, and is referred to as depletion weighting. In other words, depletion weighting is a technique that may be used to drive the system to the point of legality in an SAF flow via dynamical means. By providing a dynamical solution to the problem, a higher quality result may be obtained in some usage scenarios. In certain embodiments depletion weighting operates by attaching a modifier to the density contributed by a node and the expansion field force acting upon it. In some embodiments an expansion field without depletion weighting is used. In some embodiments an expansion field with depletion weighting is used. In some usage scenarios the depleting weighting improves any combination of actual node resource footprint, block footprint, and block capacity. In some usage scenarios the depleting weighting results in nodes being driven apart only as far as necessary to achieve legality. In certain embodiments the depletion weight is calculated from a weighted sum of the differences between the available resources and the node resource footprint onto a quantization block, i.e. the amount of resource depletion caused by presence of the node in its current state. The depletion weight acts as a simple linear weight modification to both the density contributed by the node (in accumulation processing phases) and force acting on the node (in interpolation processing phases), and dependencies computed as: dpwt=(1+m)ˆpdpwt where pdpwt is the power-law configuration parameter (that in certain embodiments defaults to 0, i.e. no modification), and the modifier “m” is as defined below. There is in addition a linear term and configuration parameter cdpwt (that in certain embodiments defaults to 1, i.e. no modification) that in some usage scenarios enables improved results compared to the power-law form alone. The weights are computed differently if the quantization block is depleted in any one of the resources required for the node. For example, a node may be oversubscribed in only a single resource, but undersubscribed for others, leading to no net result unless resources are considered individually. Thus, if any resource appears depleted with respect to requirements for a node, then only the depleted resources are considered. In some usage scenarios the node is thus “coerced” out of a quantization block by depletion weighting related expansion forces. The following equations are used when there is depletion for at least one resource. Nomenclature: f_a node footprint for atom (a) b_f_a block footprint for atom (a) b_c_a block capacity for atom (a) For overfull (i.e. depleted) quantization blocks, the modifier m is given by: m=cdpwt*sum—a{f—a*(b—f—a−b—c—a)/b—c—a} where only terms with (b_f_a−b_c_a)>0 are considered, sum_a indicates a sum over all values of iteration variable “a”, and the term atom refers to a slot in an underlying SAF. The modifier ensures that (a) resources that are more limited are given higher weight, and (b) nodes possessing multiple depleted resources have higher weight. For the case of no depletion, the modifier m is given by: m=sum—a{f—a*(b—f—a−b—c—a)/b—c—a/b—c—a}/sum_a{f—a/b—c—a} where (compared to the depleted block case) additional terms serve to map the amount of depletion onto the range [−1,0] (resulting in a weight in the range [0,1]). Thus m=−1 is the minimum when the block is completely empty and m>0 when the block is full. In some embodiments depletion zones may be treated differently from one another. In some embodiments a simpler normalization multiplier is used, i.e. 1/sum_a{f_a}, having the effect of treating all depletion zones equally. In some embodiments where depletion zones are treated differently from one another, depletion weighting tends to reduce density contributed by nodes that “fit” and to increase density for nodes that “don't fit”. Also, nodes that fit tend to be affected by weaker expansion forces and nodes that don't fit tend to be affected by stronger expansion forces. Thus the net effect of the depletion weighting is that nodes that easily fit contribute a smaller density and are affected by a lesser force from the expansion fields, but nodes that don't fit contribute a larger density and are affected by a stronger force. The variation in forces tends to contribute to forward progress in several ways. The density differential between nodes that are fitting and those that are not creates a situation where the system naturally (thermodynamically) evolves to a lower energy state, where everything fits. Also, the force differential provides a direct dynamical mechanism to cause non-fitting nodes to leave an overfull block (as a result of the density surplus and the attendant local expansion field) before other nodes get a chance to leave the block. In some embodiments a depletion weight technique calculates the node depletion weight at each of the nearest neighbor grid points used in the accumulation and interpolation, so that nodes near a block boundary are subject to forces due to the inclusion of the node in the neighboring block as well the bock the node is included in. In certain usage scenarios this prevents nodes from oscillating (or “sloshing”) between blocks when there is likely no benefit to be gained from the oscillation. The induced per-block expansion field tends to drive non-fitting nodes towards the boundary where they may tend to cluster temporarily if the neighboring block does not have the capacity to accept them. The cluster may be, however, a transient effect. Nodes that are bunched near the edge of a block either slide along the edge until reaching an accepting block on either side, or hover at the edge until conditions in the nearest neighboring block become favorable for transit. Exclusion Zones In some embodiments various regions, or exclusion zones, may be defined that are not allowed to include any morphable-devices, any placed elements, or any elements of certain types, according to various usage scenarios. During later stages of global placement iterations, exclusion zones may be processed to provide gradually growing regions of higher density fields that result in repulsing forces that tend to expel nodes from the exclusion zones. In certain embodiments the exclusion zones “grow” as simulation time moves forward, starting out as point particles (like nodes), as miniature representations of the desired exclusion zone (the miniature having an overall shape and aspect ratio equal or nearly equal to the desired exclusion zone), or as two-dimensional lines, according to various usage scenarios. Subsequently the starting representation evolves into an ever-growing object until the object matches the desired exclusion zone in size and location. Similarly exclusion zones specified as strips across the entire area being placed and routed begin as an exclusion line and grow over simulation time into an exclusion area equal in dimension and location to the required exclusion zone. Exclusion zones (also referred to as “xzones”) are a way to model architectural entities that explicitly prohibit inclusion of all non-qualifying node (or corresponding device) types, while preserving the SDI-based numerical model. In certain embodiments all adjacent xzones are collapsed into a single xzone, to simplify treatment. In some embodiments simulation proceeds according to the laws of motion defined elsewhere herein, ignoring xzones, allowing the netlist a relatively large amount of time for detangling. Once the nodes are suitably spread, a transition is made to “exclusion mode” where the xzone constraints are obeyed. A first technique to manage the transition is to explicitly move nodes out of the way, starting from the center of the exclusion zone and continuing outward. In some embodiments the outward processing is gradual to reduce disruption caused by spatial shifting of the nodes. The center of the xzone and moving xzone boundaries are defined to push nodes in a desired direction, i.e. in the direction of accessible final placement states. For exclusion zones that are in the form of a stripe along the entire chip area, nodes are moved to one or both sides as appropriate. For exclusion zones that are in the form of isolated rectangles, the nodes are moved in a ray from the center point to the affected node, to spread out the distribution in an isotropic manner. A second technique is to apply an artificial density enhancement to the area inside the exclusion zone as it slowly expands. In this technique, twice the average density on the xzone boundary is imposed in the interior of the xzone during transition. This provides a dynamical shove against the nodes in advance of the approaching barrier. After the xzone transition is complete, simulation continues as during the xzone transition, but with added constraints including: Nodes are snapped to xzone boundaries at the end of each timestep. A node may “tunnel” to the other side of an xzone if energetically favorable (see “Tunneling Congestion Relief” located elsewhere herein for additional information); and The density fields obey specified parity boundary conditions at the edge of each xzone, to ensure physically relevant behavior at the boundary. In some implementations even parity is used, and in some implementations periodic parity is used. Simultaneous Dynamical Integration (SDI) Simulation SDI simulation (also known as Particle In Cell (PIC) simulation) provides approximations to solutions of Newton's second law (i.e. force equals mass multiplied by acceleration, or F=ma), as expressed by a system of coupled ordinary differential equations. For each node, the sum of the forces (also known as forcing terms) acting on the respective node is equal to the mass of the respective node multiplied by the second derivative with respect to time of the state-space representation of the node. In some embodiments nodes are restricted to planar (i.e. two-dimensional) movements, and there are four equations per node (x-position, y-position, x-velocity component, and y-velocity component). In some embodiments nodes are not so restricted (i.e. allowed three-dimensional movements), and there are six equations per node (x, y, and z-positions, and corresponding velocity components). FIG. 4 is a flow diagram illustrating selected details of an embodiment of SDI modeling and simulation, such as operations referred to elsewhere herein (“SDI Simulation” 306, of FIG. 3A, for example). Overall the illustrated processing serves to advance a dynamical system simulation forward in time, updating state-space variables according to Newtonian mechanics. Processing begins (“Start” 401) and the system of coupled ordinary differential equations is approximately solved by numerical integration for a short delta simulation time interval (“Integrate Time Forward” 402). Changes to all of the state variables for all of the nodes are then simultaneously processed (“Update State Variables” 403), based on the numerical integration. In some embodiments relatively small-scale changes are then made to one or more of the forces and masses of the system (“Micro Adjust Forces” 404 and “Micro Adjust Masses” 405), according to a specified or a computed rate of change, in certain usage scenarios to provide more nearly continuous changes to state-space variables than would otherwise be possible. The changes to the force(s) are in addition to changes naturally arising due to the advancement of simulation time. For example, in some embodiments large-scale force (and mass) changes (such as “Macro Adjust Forces” 304 and “Macro Adjust Masses” 305, of FIG. 3A) are partially effected by incremental changes. The new system state is examined (“Finished” 406) to determine if the SDI simulation is complete via a test of an end condition. An example termination condition is completion of simulation of a specified time interval. If the SDI simulation is finished (“Yes” 406Y), then processing is complete (“End” 499). If the end condition is not satisfied, then flow loops back for further simulation forward in time (“No” 406N). In some embodiments configurable settings are adjusted prior to or in conjunction with continuing SDI simulation (such as settings associated with “Commands and Parameters” 130, of FIG. 1). Numerical integration techniques compatible with the time-integration include Runge-Kutta, predictor-corrector, leap-frog, and other similar integration techniques. Various embodiments use any combination of integration techniques. In some embodiments the time-integration is according to a fixed timestep, while in other embodiments the integration is according to an adaptive timestep. The adaptive timestep results in reduced integration costs during system simulation time periods of slowly changing state variables and improved numerical accuracy during system simulation time periods of rapidly changing state variables, or otherwise “stiff” governing equations. In some embodiments the integrator (such as used in “Integrate Time Forward” 402) receives an input Delta-t (an amount to advance system simulation time). In some embodiments the integrator provides an actual Delta-t (an amount system simulation time actually advanced during the integration) and a suggested Delta-t for use in succeeding integration timesteps. In some of the adaptive timestep embodiments one or more of the actual and suggested Delta-t values are used to control the adaptive timestep. While the discussion of SDI is specific to global placement, the technique is applicable to other functions of the aforementioned place and route flow, including any combination of global placement, legalization, detailed placement, and routing. Legalization Conceptually legalization determines if the global placement is likely to be usable for a successful detailed place and route, and if not, legalization attempts to improve placement before proceeding to detailed placement. The determination of suitability for detailed placement includes assessing one or more metrics correlated with local solvability of placement (and routing) problems not addressed by global placement. In some embodiments one of the metrics includes sectioning all of the devices according to a grid (such as a regular grid) of analysis windows, and determining locally if within each analysis window resources exceed (or fall below) requirements. If all of the analysis windows are simultaneously solvable (i.e. available resources meet or exceed requirements), then detailed placement and routing is likely to succeed without additional refinements to the global placement. Improvements, or corrective actions, may take various forms including any combination of “moving” devices from one region to another, transforming devices from one implementation form to another, and partitioning-related strategies. FIG. 5A is a flow diagram illustrating selected details of a first embodiment of resource reconciliation, as a first example of legalization (such as “Legalization” 203, of FIG. 2). Overall the flow includes determining a size of an analysis window and allocating all devices in groups to their respective containing windows, and sub-dividing and transforming logic functions to reduce resource over-subscription. The flow also includes checks to determine if the devices allocated to each window may be implemented with the resources available in the window (i.e. no analysis window is over-subscribed), and if continued iterations are likely to provide improved results. Processing begins (“Start” 501) with global placement information (such as produced by “SDI Global Placement” 202, of FIG. 2, for example). The global placement result may not be legal (i.e. in a standard cell flow devices may be overlapping, or in a structured array flow more resources may be used than are locally available), but is good enough to continue processing via refinement techniques implemented in legalization. An analysis window is determined (“Quantize” 502), corresponding to a quantization block size, and conceptually replicated in a regular contiguous (but not overlapping) fashion such that all of the devices in the netlist are allocated to one (and only one) window (some windows may be devoid of devices). In some embodiments relating to a structured array design flow, the analysis window is a rectangular shape having a size that is an integer multiple of a corresponding SAF tile. In some embodiments the analysis window is aligned with respect to SAF tiles. A first determination as to whether all of the analysis windows (also referred to as quantization blocks or simply “Q-Blocks”) are simultaneously legal, i.e. none are over-subscribed, is made (“All Q-Blocks OK?” 503). If all of the Q-Blocks are legal, then legalization processing is complete (“OK” 203Y) and processing continues to detailed placement (see FIG. 2). Otherwise (“No” 503N) the devices are sub-divided (“Partition” 504) via partitioning strategies including any combination of fixed blocks, recursive bisection, and other similar techniques, according to embodiment. A second legalization check is performed (“All Q-Blocks OK?” 505) that is substantially similar to the first check. As in the first checking case, if all of the Q-Blocks are legal, then processing is complete (“OK” 203Y) and the legalized result is ready for detailed placement. Otherwise (“No” 505N) the devices are transformed (individually or in groups) to logically equivalent formulations having reduced resource over-subscription (“Morph” 506). The transformation, or morphing, operations are directed to manipulate the netlist such that logic functions requiring resources not available in a Q-Block are implemented as logic functions using resources that are available. As an example, an OR function required in a Q-Block exhausted of OR gates may instead be implemented as a NOR gate followed by an inverting gate, if a NOR gate and an inverting gate are available in the Q-Block. Morphing may be used in usage scenarios including structured array regions. A third legalization check is performed (“All Q-Blocks OK?” 507) that is also substantially similar to the first check. As in the first checking case, if all of the Q-Blocks are legal, then processing is complete (“OK” 203Y) and the legalized result is ready for detailed placement. Otherwise (“No” 507N) a determination is made as to whether further legalization iterations are likely to result in improvement (“Continue?” 508). If continuing is potentially beneficial (“Yes” 508Y), then one or more adjustments are made to the analysis windows (“Adjust Q-Blocks” 509), and flow loops back to repeat processing starting with quantization. In some embodiments the adjustments include increasing the Q-Block size in one or more dimensions according to a granularity that is an integer multiple of a corresponding dimension of an underlying SAF tile. For example, the Q-Block size may start out as “1 by 1” (i.e. equal in size to the SAF tile), then be increased by one in the first dimension to “2 by 1” (i.e. twice the SAF tile size in the first dimension), and then be increased by one in the second dimension to “2 by 2” (i.e. twice the SAF tile size in the second dimension). Alternatively, the Q-Block size may be successively lowered, or may be increased in one dimension while being decreased in another, according to various embodiments. More than one Q-Block size choice may result in legal or otherwise useful results, according to various characteristics of the results (such as minimum and maximum local resource utilization, and other similar metrics). If it is determined that continuing legalization processing is not useful (i.e. not likely to further a solution), then processing is also complete (“Not OK” 203N) and subsequent processing includes one or more revisions (see FIG. 2). In some embodiments checking if a Q-Block size equals or exceeds a predetermined value (either before or after one or more adjustments) is part of the continuation determination, as legalization achieved with relatively smaller Q-Block sizes, in some usage scenarios, is more likely to result in successful detailed placement. FIG. 5B is a flow diagram illustrating selected details of a second embodiment of resource reconciliation, as a second example of legalization (such as “Legalization” 203, of FIG. 2). Flow begins (“Start” 520) and proceeds to determine a window for quantizing (“Quantize at Specified Window Size” 521), binning elements into Q-blocks and optionally morphing selected elements to find a legal result. All Q-Blocks are then tested to determine if or to what extent resource conflicts exist (“All Q-Blocks Legal?” 522). If all Q-Blocks are simultaneously free of resource conflicts (“Yes” 522Y), then processing proceeds to mark the current state as a possible solution (“Nominate Current System State as Candidate Solution” 531). A test is then made to determine if the current Q-Block is a minimum size Q-Bock (“Q-Block Window Size at Smallest Possible Dimensions?” 532). If so (“OK” 203Y), then processing is complete and the result is ready for detailed placement. If the current Q-Block is not the minimum size (“No” 532N), then processing proceeds with a smaller window (“Reduce Target Q-Block Window Size” 533). Flow then loops back (“Go to Start” 535) to attempt processing with the reduced window size. If at least one Q-Block has a resource conflict (“No” 522N), then a determination is made as to the severity of the remaining conflicts (“Characterize Extent of Quantization Failure” 523). In some embodiments the determinations include “Easy”, “Hard”, and “Extreme” cases. Relatively simple conflicts (“Easy” 528) are processed by depletion weighting (“Activate/Tune Depletion Weighting” 524), and relatively more difficult cases (“Hard” 529) are processed by modifications to repulsive (or spreading) force sources (“Adjust Spreading Field Strengths” 525). Processing for the Easy and Hard cases then flows back to repeat all or portions of global placement (as revisions in the context of FIG. 2) according to depletion weighting activation/tuning or adjusted spreading strengths (“Back to Global Placement” 527 and then “Not OK” 203N). Substantially more difficult cases (“Extreme” 530) are processed by partitioning (“Go to Partitioning” 526). The determination of conflict severity or difficulty may include examination of objective factors (such as a ratio of resources demanded compared to supplied in the Q-Blocks or other computable figures of merit), and may also include examination of subjective factors (such as how much processing time has already been expended during legalization, and other similar progress indicators), according to various embodiments. In certain usage scenarios, upon entry to legalization, there may be a subjective perception that the system is far from legal due, for example, to over-concentration of nodes of one or more resource classes (such as Nand2, Nor2, Mux2, Inverter, and so forth) in certain regions. In some usage scenarios the strength of the spreading forces acting on the over-concentrated resource class is increased, and earlier processing (such as global placement processing with revisions via “Not OK” 203N of FIG. 2) is repeated. In other usage scenarios, if the resource imbalance is mild, then an attempt may be made to gently nudge the system with depletion weighting activated as revised global placement processing (such as via “Not OK” 203N of FIG. 2). However, if extended time-evolution with increasingly powerful depletion weighting does not resolve the conflicts, then in certain embodiments the quantization failure may ultimately be deemed “Extreme” even though only a comparative paucity of Q-Blocks show only slightly over-subscribed resources. As the depletion weighting influencing factors become increasingly strong, the governing dynamical equations become stiff, and the overall assessment of legalization difficulty may be escalated to extreme, even though over-subscription is small. According to various embodiments assessment of legalization difficulty includes any combination of examining the system state, the netlist topology, the timing constraints and the architecture definition. In some embodiments of the flow for standard cell implementation technologies, legalization may be pursued via modifications or adjustments to the spreading force strength. For example, the masses of nodes may be directly correlated to the areas of the standard cells, and the capacity of each Q-Block directly correlated to the respective Q-Block area. Thus spreading forces may be used to drive density so that area consumed by nodes within a Q-Block is no greater than the area of the Q-Block. When achieved, legalization is complete and flow proceeds to detail placement. In some embodiments legalization may be pursued via partitioning, optionally in combination with spreading force strength adjustments. Partitioning FIG. 5C is a flow diagram illustrating selected details of an embodiment of partitioning (such as processing performed as a result of “Go to Partitioning” 526, of FIG. 5B). Flow begins (“Start” 540) and then a technique for partitioning is chosen (“Select Partitioning Algorithm” 541) via any combination of manual (user directed) or automatic (software determined) mechanisms, according to various embodiments. If a Q-Block technique is chosen (“Q-Block Edge Flow” 542), then processing is performed for each Q-Block (“For Each Q-Block” 543). If a Bi-Section technique is chosen (“Recursive Bi-Section” 548), then processing is performed for each of a set of progressively smaller windows (“For Each Window” 549), starting, in some embodiments, with a window size equal to the entire place and route region, and proceeding to progressively smaller and smaller windows. Processing for each Q-Block according to the Q-Block edge flow technique includes determining nodes causing resource conflicts (“Identify Nodes Impinging on Over-Subscribed Resources” 544), followed by choosing an exit edge (“Pick Edge to Flow Through” 545) for the nodes that are impinging. Then the nodes are ranked, for example, by separation from the chosen exit (“Prioritize by Distance to Edge” 546) and then moved across the exit edge (“Push Nodes Across Edge Until Legal or Balanced With Respect to Resource Class” 547), thus entering a different Q-Block. After all Q-Blocks have been processed, a determination is made as to whether a legal result has been obtained (“Legal Result?” 559). If a legal result has not been obtained, then one or more revisions are indicated and earlier processing is repeated ((No) “Not OK” 203N). If a legal result has been obtained (“Yes” 559Y), then the current configuration is nominated as a candidate solution, as in other legalization techniques (“Nominate Current State as Candidate Solution” 560). Processing may then proceed to detailed placement (“OK” 203Y), or may return for further legalization processing with a goal of achieving a legal result at a smaller Q-Block size (Not OK, 203N), conceptually as a revision to legalization processing as described with respect to FIG. 2. Processing for each window according to the recursive Bi-Section technique includes formulating two sections to break the window into (“Introduce Cut Line Across” 550) and then determining resource requirements and availability in each of the sections (“Count Resource Supply/Demand in Each Region” 551). Nodes are then moved between the sections (“Exchange Circuit Nodes Across Cut Lines Until Legal or Fail” 552) until successful (“Legal” 557) or no further improvements are possible (“Fail” 556). If the result is legal, then the current state is marked as a possible result (“Nominate Current State as Candidate Solution” 553) and then a determination is made as to whether a smaller Q-Block should be attempted (“Desired Q-Block Configuration?” 554). If a target Q-Block size has not been reached, then flow returns back (“No” 558) to continue bisecting windows. If the target Q-Block size has been reached, then processing is complete and flow may proceed to detailed placement (“OK” 203Y). In some embodiments the recursion operations are according to a tail recursion formulation, and testing for the desired Q-Block configuration may include a tail recursion end check (for example, if the next region is smaller than a predetermined end condition size) as an iteration termination condition for recursive window processing. In some embodiments for use in an SAF flow context the predetermined end size is equal to an SAF tile size. If no further improvements are possible (via “Fail” 556), then flow continues (“Done” 555) where a determination is made as to whether an acceptable candidate solution has been found (“OK” 203Y) and detailed placement may follow, or whether revisions and repetition of earlier processing are indicated (“Not OK” 203N). Nodes may be selected for speculative migration across the cut line according to any combination of various criteria, including proximity to an edge, a footprint onto over-subscribed resources, and any other related reason, according to embodiment. In some embodiments speculative expulsion of a node from one side of the cut line to the other side may include morphing operations on any combination of nodes on the one side, the other side, and both sides. The morphing operations are directed to discover suitable implementation forms for all nodes such that nodes in each containing region may be fully implemented using only resources in the respective containing region. Detailed Placement Conceptually detailed placement serves to fine-tune placement as produced by legalization, determining final placement of all the devices of the netlist. In certain embodiments operations are relatively limited in scope, focusing on optimizations and refinements generally limited to a region corresponding to a Q-Block. Particular detail placement techniques are described in detail in the SAF embodiments illustrated herein. Nevertheless, any of a variety of detail placement procedures and techniques may instead be employed, as the specific mechanism for performing detail placement (assignment of devices to specific, non-conflicting locations) is not a limiting aspect of the SAF techniques described herein. In some SAF embodiments illustrated herein legalization produces Q-Blocks where supply is known to meet demand. Since the SAF already has the resources laid out in some structured manner, there is thus certainty of the existence of a fitting assignment of resource instances in the netlist to resource slots in the SAF. Consequently, there is no risk of failure to find a detailed placement solution, and moreover the Q-Blocks can be detail placed independently, including in certain embodiments, in parallel, concurrent operation. Some embodiments use continuous variables during global placement to specify placement position. Conceptually, the position coordinates determined by global placement in these embodiments may be considered as “optimal” locations for each node, when interpreted as being representative of the collective configuration of all circuit elements. Detail placement attempts to find actual resource slots in the SAF for each resource instance in the netlist such that all resource instances are simultaneously slotted as close as possible to the coordinate calculated during SDI-directed global placement. Stated differently, a collective assignment of all resource instances to resource slots is sought for each resource class in the SAF, such that the overall variance from the coordinates assigned by global placement (and possibly modified during legalization) is minimized or reduced. Some embodiments slot each node independently in the closest available unoccupied slot (instead of prioritizing individual nodes). FIG. 6 is a flow diagram illustrating selected details of an embodiment of detailed placement useful in a variety of applications (such as processing performed in relation to “Detailed Placement” 204 of FIG. 2). The illustrated flow may be used in design techniques relating to SAFs. Overall the flow includes determining a prioritized order to satisfy resource requirements and performing limited-scope optimizations, according to various embodiments. The flow may iterate internally to provide successively more refined solutions, and terminates when an acceptable result is found, or when it is determined that further iterations are not likely to produce improved results. Flow begins (“Start” 601) upon receipt of placement information as produced by legalization (such as “Legalization” 203 of FIG. 2, for example). As represented by “Assign Resources” 602, resources are prioritized by class. In an illustrative embodiment the prioritization is in accordance with a function of demand for resources of a respective class and supply of SAF resource slots, the slots being consumed by the resource instances of the respective resource class. The prioritization is carried out such that as the percentage of consumed slot supply increases, the priority of the respective resource class is increased, and as the supply of resource slots increases (irrespective of demand), the priority of the respective resource class is decreased. The function is used to evaluate the priority of each resource class, and assignment of resource instances to resource slots is performed one resource class at a time, in the determined priority order of resource classes. In some of embodiments the prioritization is done on a Q-Block basis. That is, the function is evaluated with respect to the demand, supply, and consumption local to each Q-Block. Iterating through resource classes in priority order, within each resource class the resource instances impinging upon the respective resource class are identified, and an initial assignment of resource instances to resource slots is generated, with each resource instance drawing the closest still-unoccupied resource slot currently available. Closeness is measured in terms of distance from a slot center to the coordinate assigned by global placement (and possibly modified by legalization), for the node containing the resource instance. Processing continues with a first form of limited-scope refinement (“Pairwise Interchange” 603), where selected pairs of allocated resources are interchanged in an attempt to discover an improved solution. In certain embodiments, within the set of resource instances previously assigned slots, speculative interchanges are considered between every instance and every other slot (whether occupied or not). In other words, a resource instance may be swapped with the instance occupying another slot, or may simply be moved to an empty slot. Each speculative interchange is scored according to a function of the slot position and the preferred position of the occupying resource (as assigned by global placement and possibly modified by legalization). An example function is the sum of the squares of the distances between the slot centers and the preferred positions. Speculative interchanges are accepted with strictly greedy semantics, on the demonstration of a reduced sum of squared distances from instance to slot. The interchange process will eventually stall when the collective variance of resource instances from desired positions can no longer be strictly reduced. In some embodiments pairwise interchanges may be evaluated according to a predicate: D(p—i,s—j′)ˆ2+D(p—i′,s—j)ˆ2<?D(p—i,s—j)ˆ2+D(p—i′,s—j′)ˆ2 where p_i is the ideal position of node I; s_j is the actual location of slot j; and D(p_i,s_j) is the distance between p_i and s_j. The sum of D(p_i,s_j′)ˆ2 over all assignments (i->j) is minimized, according to the predicate. When the collective variance may no longer be reduced, any resource instances of other resource classes that are associated with composite forms (i.e. forms realizable from resources of more than one slot, such as an And2 realized from a Nand2 slot and an Inverter slot) participating in the pairwise interchange are placed in an available slot (corresponding to an ancillary resource) that is closest to the resource instance of the respective composite form. The (ancillary) resource instance slot assignments are then marked as locked, and the ancillary instances are thereafter excluded from the set of assignable and revisable resource instances to be placed when a corresponding resource class is subsequently processed. When all resource classes in the SAF have been processed as described above, a complete and valid initial detail placement for one Q-Block has been rendered, and subsequent optimization processes are enabled. In certain embodiments, the above processes (“Assign Resources” 602 and “Pairwise Interchange” 603) are used in combination with “Dynamic Morphing” 604. In some dynamic morphing embodiments note is made of resource instances that are placed farthest from a respective desired location and improved placement of the forms is attempted by morphing to a functionally equivalent available destination form having a more suitable placement configuration of resources instances. In certain dynamic morphing embodiments, such speculation over implementation form for netlist nodes is combined with iteration over slot assignment and pairwise interchange. In the latter dynamic morphing embodiments various visited states are scored according to collective variance from preferred locations (as described above) and the best state that can be found is taken as a result. In certain embodiments states visited are limited by a computational cost criteria. Flow then continues to a third form of limited scope refinement (“Pin Swap” 605), where pin swapping directed to improve routability is performed. Here, speculation is performed over various functionally equivalent mappings of netlist nets to instance pins. As an example, the inputs of a NAND gate may be interchanged without changing the function implemented in the gate. This and other similar equivalent mappings for other gates and circuitry are selectively evaluated. By considering such netlist transformations, attempts are made to reduce the difficulty of achieving a fully routed circuit layout. In some embodiments an optional first-cut attempt at improving timing paths is then performed (“Size Devices” 606). As an example, driver sizing is selectively performed by revising the netlist to employ forms composed of resources with higher drive strengths. Optimization is not limited to such up-sizing. Selective down-sizing of drivers on non-critical paths is also performed, to free up high drive strength resources (such as in an SAF) for use by paths that are more critical. A determination is then made (“Repeat?” 607) as to whether additional iterations of all or part of the detailed placement flow is likely to improve results. If so (“Yes” 607Y), then processing loops back to resource assignment and continues forward again from there. If further iterations are found to be unlikely to offer improvement (“No” 607N), then a determination is made as to whether the results are acceptable (“OK Result?” 608). If so (“OK” 204Y), then processing is complete and ready for routing. If the results are not acceptable (“Not OK” 204N), then processing is also complete and subsequent processing includes one or more revisions (see FIG. 2). The repeat and acceptable determinations are made by any combination of automatic (such as software) and manual (such as human inspection) techniques, according to various embodiments. FIG. 6 is an illustrative example of detailed placement, as the order and/or presence of operations 602 through 606 will vary according to embodiment. That is, many combinations of “Assign Resources” 602, “Pairwise Interchange” 603, “Dynamic Morphing” 604, “Pin Swap” 605, and “Size Devices” 606, will have utility as embodiments of detailed placement, including combinations reordering and/or omitting one or more of these operations. As specific examples, some embodiments perform “Assign Resources” 602 and “Pairwise Interchange” 603 but omit “Dynamic Morphing” 604 and “Pin Swap” 605, while other embodiments selectively perform “Dynamic Morphing” 604 and then subsequently perform “Assign Resources” 602 and “Pairwise Interchange” 603. Another embodiment of detail placement re-employs SDI-directed placement methodology (targeted at a resource-level netlist) optionally constrained to a reduced sub-circuit present in a specific Q-Block. In the SDI-directed detail placement embodiment, the specific forcing terms in the system of simultaneous governing equations are modified from that described in global placement, and force models more appropriate to detail placement are substituted. For example, in detail placement, once the Q-blocks are formed and legalized, there is no further need to perform inter-Q-Block interchange of nodes. Consequently the bulk density fields that were used in global placement to control unsustainable over-concentrations of specific resource types are unnecessary by construction in the detail placement context. Thus the bulk density fields are replaced by forcing terms that represent a spring drawing the resource-level instances of each form toward the position assigned by global placement. Simultaneously, overlap repulsions arising from pair-wise occupancy exclusions between resource instances of each resource class act to drive the resource instances toward feasible slots while preserving the topological disentanglement that was a key result of the global placement previously obtained by SDI-directed techniques. The illustrated SAF embodiments emphasize a conceptual separation between global placement, legalization and detail placement, as facilitated by the described form-level netlist abstraction and the technique of morphing and facilitating data structures and SAF enabling properties. The approaches to detail placement used in the illustrative SAF embodiments herein are not meant to be limiting and other detail placement approaches may be substituted. In some standard cell implementation technologies, there is no concept of resource classes. In some usage scenarios “slots” correspond to tiled regions of a defined size. Any standard cell may be positioned at any location on a so-called standard cell grid, with the understanding that each standard cell consumes some number of contiguous abutting slots, and that neighboring standard cell instances are non-overlapping. In some implementations assessment of Q-Block legality by comparing demand for standard cell slots to the capacity of the Q-Block (determined by counting the number of contained standard cell slots), is an uncertain predictor of detail placement success. As an example, consider a Q-Block that is 10 standard cell rows high by 100 standard cell columns wide. The assigned standard cells in the Q-Block would be organized into no more than 10 rows, each row limited to 100 units (standard cell columns) in length. A detail placer may be unable to construct row-sets of instances. Continuing the example, consider 11 standard cell instances of a single cell type, the single cell requiring 51 standard cell columns. Then the Q-Block would be infeasible, even though the slot supply comfortably exceeded demand. As a result, standard cell embodiments may use a quantization (a Q-Block sizing) that is enough larger than the largest frequently occurring standard cell (in certain usage scenarios standard cells having sequential logic, a.k.a. “sequentials”) to improve the likelihood that over-concentrations of unwieldy standard cells will succeed during the slot assignment phase of detail placement. In some embodiments of a detail placer for standard cell design flows the detail placer may include a mechanism for feeding back from detail placement to legalization. In one representative standard cell embodiment, the feedback includes operating an iterative partitioner included in the detail placer. Solution of each Q-Block is attempted. If any fail, then the capacity of the failing Q-Blocks is artificially depressed. The partitioner then runs to attempt to redistribute the netlist nodes to distort the net topologies to the least possible extent, while still achieving resource legality in each Q-Block, including the effect of the artificially depressed capacity of certain Q-Blocks for the purpose of inducing the system to move some cells to different neighboring Q-Blocks in the hopes of finding a soluble configuration. Some embodiments targeting standard cell flows are based upon a conceptual framework where the global-placement position coordinates assigned to each netlist node are deemed ideal when considered as a collective determination, not as an individual determination. Consequently, the standard cell embodiment partitioner preferably seeks to move across the failing Q-Block edges whatever is already closest to the edge, and that can therefore be displaced slightly with the least distortion in the overall netlist net topology. In another representative standard cell embodiment, the cells in a Q-Block are grouped into rows, determined through considering relative juxtaposition of the cells in the coordinate that varies perpendicularly to the standard cell rows (such as the y coordinate). Thus cells at higher y position coordinate will be promoted to the row above in preference to cells with lower y position coordinate. Once the rows are formed and the contents optimized until each row fits in the width of the containing Q-Block, layout within the rows proceeds in a similar fashion. Specifically, cells are laid out horizontally within each row, and the global placement assigned x position coordinates are used to determine relative packing order along the standard cell row within each Q-Block. In another representative standard cell embodiment, the detail placement is solved via a re-employment of the SDI-directed techniques described previously for global placement. The spreading fields of global placement are replaced with forcing terms modeling a spring drawing each netlist cell instance toward the respective node position coordinate determined by global placement. Moreover, pairwise overlap repulsion interactions between neighboring nodes are included and tend to tile the nodes toward net disentanglement. In variations of embodiments of detail placement for standard cells, further optimizations may be performed through orientation speculation and pin swapping, e.g. to reduce routing congestion. The optimizations are based upon the observation that each net that crosses a given line contributes to demand for tracks crossing the line. If the demand for the tracks crossing the line exceeds the supply of perpendicular-running tracks, then routing is more difficult. However, the condition of over-demand for routing tracks may be highly localized. If nets crossing the line from opposite directions to reach pins on either side can be swapped, then the track demand is reduced by two. Techniques include pin swapping by exploitation of pin permutability semantics on an underlying standard cell (such as swapping inputs on a NAND gate) and by rotation and flipping a standard cell according to standard rules of the implementation architecture. Timing Closure and Timing-Driven Placement Conceptually timing closure and timing-driven placement operate to reduce critical timing delays to facilitate higher-speed operation of an implementation of a netlist. A high fidelity timing kernel, in conjunction with precise modeling of interconnect parasitics, specifies timing-driven attractive forces, or modifies effects of one or more net attractive forces used during SDI-directed global placement. Timing-driven forces are derived from a snapshot of state variables of the time-evolving dynamical system simulation. As the dynamical system changes (due to influences of various forces, for example), electrical characteristics of a placement of the associated netlist also change, and effects of the new state variables (such as longer or shorter interconnects) are fed back into a timing kernel to reevaluate timing characteristics of a placement corresponding to the state variables. In some embodiments timing-driven forces are calculated and applied to nets selectively, in certain embodiments as a function of any combination of one or more slack coefficients, worst negative slack values, and total negative slack values. In some embodiments timing forces may also be derived using a path-based approach, where the paths include various critical and near-critical paths according to a placement of the netlist as indicated by the state variables. Various quanta of SDI simulation time may advance between timing-driven force re-calculation, from as frequently as a single SDI iteration to as infrequently as an unbounded number of SDI iterations. For example, timing-driven forces may be adjusted on every iteration of the integration timestep or every N iterations, where N may be provided by a user, or determined by software, according to embodiment. In some embodiments, the frequency of timing update may be automatically computed by the timing kernel (in an “auto timing-directed-force update mode”) depending on the state of the dynamical system. For example, when the system is “hot” (i.e. has a relatively high ratio of kinetic energy to total energy), timing force updating is performed more frequently than when the system is “cold” (i.e. has a relatively low ratio of kinetic energy to total energy). In some embodiments the update frequency is determined in part by tracking system parameters including any combination of a cumulative node displacement since last update, a maximum displacement per net, and other similar metrics to trigger an auto-update of timing forces. An incremental timing update is performed on a timing graph when relatively small displacements of nodes are detected with respect to the prior update. Iterative slack allocation and net delay budgets are computed on the instantaneous placement every N iterations to adapt the timing budgets based on the time-evolving placements. Certain high fanout (or portions of high fanout) nets are identified as non-critical with respect to timing and have little or no timing-driven forces associated with them. False timing paths and non-critical multi-cycle timing paths are also identified as non-critical and receive little or no timing-driven force enhancements. In some usage scenarios control nets such as reset and one or more clocks may be recognized as timing non-critical. Timing critical nets (or portions of nets) are identified and receive relatively stronger timing-driven forces, in certain embodiments based on normalized timing slack determined for the net. Thus a distinct timing-driven force component may be associated with every pin on every net (or any sub-grouping thereof). In embodiments where the connectivity-based net attractive force is equal for each pin on a net, the timing-driven force tends to enable prioritizing resultant physical location according to greater timing criticality. At a macroscopic level, timing-driven forces tend to keep timing critical and near timing critical devices in relatively close physical proximity, thus reducing associated parasitics and improving timing performance. The timing-driven forces also tend to guide placements toward solutions where relatively higher drive strength devices are associated with relatively greater parasitic loads (corresponding to longer wire lengths) and relatively lower drive strength devices are associated with relatively lower parasitics (corresponding to shorter wire lengths). In some embodiments parasitics (for example parasitics of relatively short interconnects) are estimated using a simple bounding box model (i.e. net parasitics are estimated as the product of a semi perimeter of a bounding box of the pins on the net multiplied by a constant wire capacitance per unit length). In some embodiments transformations including buffering, clock tree synthesis, driver resizing, timing-based restructuring, and incremental timing post fixes are ignored during parasitic estimation, while in other embodiments the transformations are accounted for by various estimation techniques. In some embodiments parasitics (for example parasitics of relative long or relatively high fanout interconnects) are estimated after inserting buffer trees and building heuristically constructed near-Minimal Rectilinear Steiner Trees (MRST) of the high fanout nets to accurately and efficiently estimate circuit timing. In some embodiments devices are modeled as having an effective resistance that ignores input ramp time and non-linear timing response effects of the device based on output capacitive load. In some embodiments a high fidelity timing kernel propagates input ramp rise and fall times (treating them separately), and simultaneously propagates circuit ramp time from various timing start points to various timing end points. Timing exceptions (such as false and multi-cycle paths) are propagated through the timing graph to account for effects of the exceptions. In some embodiments, during placement, a lumped capacitive interconnect delay model that ignores effects of distributed Resistance-Capacitance (RC) trees is used to estimate selected parasitic effects. In some embodiments actual net routing information (or approximations thereof) forms a basis for generation of one or more distributed RC trees for estimating selected parasitic effects. In some embodiments timing closure is implemented in a Timing Kernel (TK) that dynamically updates a timing graph based on current placement state (that is in turn derived from the locations of the nodes in the SDI simulation). Net and device delays are computed and propagated to slack results on each pin, normalized slack coefficient(s) are determined, and then updated timing-driven forces are generated for use by subsequent SDI simulation. The timing graph is a graph data structure representing the netlist and includes pre-computations and pre-propagations of user-defined constraints including any combination of clock period, false path and multi-cycle path identifications, arrival times at primary inputs, and required times at primary outputs. In certain embodiments the timing graph is organized as a Directed Acyclic Graph (DAG) data structure. In certain embodiments the pre-computations and pre-propagations are generated only when a new netlist is provided or modifications are made to the current netlist. The timing graph includes timing node elements and timing edge elements. A timing node element represents pins of a macro (such as a morphable-device), and a timing edge element represents connectivity of timing node elements (such as a flattened or non-hierarchical net of the netlist). Timing delay through a timing node element (also known as a stage delay) is a function of several parameters, including a cell delay (Dc) and a wire delay (Dw). The cell delay is a function of input transition time and cell output loading. In some embodiments cell delay values are determined via a cell delay table lookup. The cell delay table may be representative of non-linear timing behavior and is specified in a timing library (such as a portion of “Technology Description” 121 of FIG. 1). Cell output transition times are also a function of input transition times and output loads, and are computed by the TK and propagated from inputs to outputs. A Steiner buffered tree constructor creates an interconnect tree based on coordinates of pins of morphable-devices. RC parasitics are then computed from the interconnect tree, and corresponding cell delays are computed according to pi-models of the RC parasitics. Wire delays are computed using Elmore-Penfield-Rubenstein delay models according to estimated net and pin parasitics. FIG. 7A is a flow diagram illustrating selected aspects of an embodiment of delay path reduction and minimization, as an example of timing closure (such as “Timing Closure” 205, of FIG. 2). As described with respect to FIG. 2, in some embodiments timing closure is essentially operative within global placement, rather than, or in addition to, operative external to global placement. In other words, in some embodiments timing closure operations are performed intimately with operations of global placement (such as those illustrated in FIG. 3A). Flows having closely associated global placement and timing improvement are known as having timing-driven global placement. For example, timing-driving forces may be adjusted (such as in “Macro Adjust Forces” 304) on every iteration (via “Repeat?” 307), or the timing-driven forces may be adjusted every N iterations, where N is computed or is provided by a user (such as via “Commands and Parameters” 130, of FIG. 1). The following discussion is according to timing closure operation within global placement, however the technique is applicable in other contexts. Processing begins (“Start” 701) with new morphable-device locations as derived from SDI simulated time advancement and resultant node location evolution. Timing node element locations and associated pin spatial positions are updated accordingly in a timing graph (“Update Pin Coordinates” 702). Approximate interconnect distributed resistance and capacitance values are determined (“Estimate Parasitics” 703) via any combination of an NBB technique (such as for short interconnects) and a Steiner-route technique (such as for long interconnects). Driver trees are then added for long and high fanout nets, and nets exceeding a specified maximum capacitance threshold (“Insert Buffers” 704). In some embodiments the driver tress are constructed according to recursive bipartition-based buffering, until a maximum drive capacity has been met. If one or more new devices are added, thus changing the netlist, then processing loops back to repeat parasitic estimation (“Changes”, 704C). If no new devices are added (for example since current buffering is sufficient or maximum drive capacity has been met), then more nearly accurate parasitic approximations are determined, in certain embodiments via Steiner-route techniques, and processing continues (“No Changes” 704N). Delays are then disseminated through the timing graph, including computing new timing edge element specific transition times (“Propagate” 705). Arrival times and required times are also propagated through the timing graph in topological order. Arrival times are propagated via a Depth-First Search (DFS) order while required times are propagated in reverse DFS order. Spare delay time is then derived for each timing node element of the timing graph (“Compute Slack” 706). The resultant slack times are then normalized and used to determine revised timing weight coefficients and associated timing-driven forces for one or more pins (“Normalize Slack” 707). In some embodiments timing-driven forces are reevaluated only for pins participating in timing critical nets. A determination is then made as to whether the timing closure is acceptable (“OK Result?” 708). If so, then flow is complete (“OK” 205Y), and processing continues to routing (see FIG. 2). If not, then flow is also complete (“No OK” 205N), but subsequent processing then includes one or more revisions (see FIG. 2). FIG. 7B illustrates a conceptual view of selected elements of an embodiment of timing-driven forces, such as used during timing-driven global placement. Driver D 715 is coupled to pins of three loads L1 711, L2 712, and L3 713, and L4 714. Each node is shown with an associated timing slack in parentheses (−2, −1, 0, and −1, respectively). Corresponding timing-driven forces are shown as F1 721, F2 722, F3 723, and F4 724 respectively. Since the timing slack for L1 711 is the most negative (−2), the corresponding timing-driven force F1 721 is the largest of the three illustrated. Similarly, since the timing slack for L3 713 is the least negative (0), the corresponding timing-driven force F3 723 is the smallest of the three illustrated. During SDI-directed placement, the action of timing forces F1 721, F2 722, F3 723, and F4 724 would be such that the dynamical system nodes corresponding to D 715 and L1 711 would experience a stronger mutual attraction than that between D 715 and L2 712, L3 713, or L4 714 other things being equal. However, in a realistic circuit, many other factors would be simultaneously considered, and moreover, more than one independent critical path could flow through any of the participating nodes. Consequently, the actual motion of the nodes may not turn out to be the same as might be indicated by such a consideration-in-isolation, as the full complexity of the dynamical system may still overcome timing forces acting on any given node. Steiner Route Tree Construction In some embodiments Steiner-route tree construction is according to a heuristic-based modified Prim-Dijkstra algorithm, including elements of Prim's Minimum Spanning Tree (MST) algorithm and Dijkstra's Shortest Path Tree (SPT) algorithm, using a coefficient alpha that is between 0 and 1. As MST yields minimum wire length (or a spanning tree) and SPT yields a minimum radius tree, the coefficient alpha enables efficient trade-offs between MST and SPT. Resistance/Capacitance (RC) Parasitic Estimation In certain embodiments, interconnect delay, or wire delay, is determined by modeling a net as a distributed RC network, with load devices presenting a capacitive load on the net. Various approximation schemes may be used, according to embodiment, to estimate the eventual routing for the net before the routing is performed (during placement, for example). The estimated routing is used in turn to derive associated approximate RC network parameters, and the RC approximations are then used to estimate timing delays, as described elsewhere herein. The RC network is divided into segments, and a wire segment delay is computed for each segment. In some embodiments the wire segment delay is computed according to an Elmore delay model (wire segment delay equals wire segment resistance multiplied by the sum of the wire segment capacitance and all of the associated input capacitances). In some embodiments the wire segment delay is computed according to a higher order moment delay calculation. In some embodiments routing associated with large (or high fanout) nets is approximated by Steiner tree graph analysis. Delays from a driver to each respective load are then determined as the sum of resistance in series between the driver and the load multiplied by the sum of the capacitance between the driver and the load, where “between” refers to the tree graph segments coupling the driver to the load. In some embodiments parasitics for short nets are estimated using net contributing factor heuristics. For example, wire capacitance from a driver to a load is equal to a load contribution factor multiplied by a “NetMSRT” multiplied by a capacitance per unit length. NetMSRT is equal to a Net Semi-Perimeter (NSP) multiplied by an “NSP-FanOut-Scaling” factor. The NSP-FanOut-Scaling factor is equal to one-half the quantity equal to the square root of the number of net loads plus one. The load contribution factor describes a relative contribution of a load with respect to all of the loads on the net, and may be expressed as the distance to the load divided by the entire length of the net. Wire resistance is derived similarly to wire capacitance, except resistance per unit length is used instead of capacitance per unit length. FIG. 7C illustrates a spatial organization (or topology) of driver D 715 and coupled loads L1 711, L2 712, and L3 713 and L4 714 of FIG. 7B. FIG. 7D illustrates an embodiment of NBB estimation of routing to cover the driver and the loads of FIG. 7C. As shown, NBB 725 covers all of the loads and the driver, and is defined by the spatial locations of D 715, L1 711, and L4 714. FIG. 7E illustrates an embodiment of a rectilinear SRT estimation to cover the driver and loads of FIG. 7C. FIG. 7F illustrates an embodiment of estimated RC parasitics associated with the RST of FIG. 7E. Timing Weights Computation In certain embodiments a timing weight is computed for all pins having a negative timing slack. All other pins are considered non-critical. Non-critical nets are marked as inactive nets and no timing forces are applied to them. Non-critical pins are assigned timing weights of zero (and thus affect no timing-driven forces). The timing weight of a pin may be modeled as a function of various timing parameters including pin slack, worst negative slack, total negative slack, interconnect length, and other similar parameters, according to implementation. In some embodiments the timing weight for a pin is equal to the square of the quantity equal to the slack of the pin divided by the worst negative slack of the entire netlist, and in various embodiments the timing weight is computed according to any number of linear and high-order calculations. The timing-driven forces are computed according to Hooke's law with a coefficient equal to the respective timing weights (i.e. timing force equal to negative timing weight multiplied by distance between driver node and load node). Selected Timing Closure User Commands Timing closure and timing-driven placement are automated to varying degrees according to embodiment. In certain embodiments the automation is controlled or directed by a plurality of control parameters provided in data files or scripts (such as via “Commands and Parameters” 130, of FIG. 1). In some embodiments a relatively small number of control parameters may be provided by a Graphical User Interface (GUI). Timing constraints are used to perform timing closure and timing-driven placement, and the GUI may also provide for user input of timing constraints files, such as Synopsys Design Constraint (SDC) compatible information, via a “source SDC” command or menu item. In some embodiments and usage scenarios design automation software (including timing closure and timing-driven placement) may be operated in a batch mode. In the batch mode any combination of selected switches may be specified in a file (such as a “schedule file”, that may be included in “Commands and Parameters” 130, of FIG. 1). A first control switch instructs SDI-driven (sometimes also referred to as force-driven) placement operations (such as operations performed by a placement engine) to apply timing-driven forces at each timestep. By default, the forces are turned off in some embodiments. Timing-driven forces are recomputed at predefined intervals, or at a selected frequency with respect to timesteps, as specified by another control switch. A second control switch instructs SDI-driven placement to perform timing analysis at predefined time intervals of the SDI simulation, and to report a specified number of critical paths or selected critical paths. In certain usage scenarios the report includes some or all of the most critical paths. If the first control switch is on, then the second control switch is automatically turned on also. However, in some usage scenarios, users may keep the first control switch off with the second control on to perform a timing analysis based on a current system configuration. Selected critical paths may then be reported at predefined intervals during SDI-driven placement. The interval may be user specified, and the reported paths may include a selection of the most critical paths, with the report including worst-negative-slack information. A third control switch controls how frequently a timing update is performed and timing-driven force computation is performed in the SDI simulation (i.e. when the first control switch is on). In some embodiments a default value for a parameter associated with the third control switch is 50; i.e. every 50 timesteps timing-driven forces are determined anew. In certain usage scenarios a larger value is specified for lager designs. For example if a design is more than one million gates, then an iteration frequency of 100 may be specified. In some usage scenarios the frequency may be adjusted dynamically (either manually by a user or automatically by software). For example, at stages of placement where changes are relatively small (such as later stages of placement), the interval may be increased. In some embodiments GUI “radio buttons” may be provided to enable a user to enable (or disable) any combination of the control switches. In some embodiments a command window (either separate from or associated with the GUI) may be used to specify the third control switch and the associated parameter. SDI-Directed Electronic Design Automation (EDA) Flow FIGS. 8A and 8B collectively are a flow diagram illustrating selected details of an embodiment of an integrated circuit Electronic Design Automation (EDA) flow using one or more techniques including SDI-directed global placement, legalization, legalization-driven detailed placement, timing optimization, and routing. In the illustrations dashed-boxes represent information provided in certain embodiments by users of the flow. In some embodiments element 815 is provided by users of the flow while in other embodiments it is generated by element 813, and thus 815 is shown having a unique dashed-box patterning. As a starting point, a design to be implemented is provided as a Hardware Description Language (HDL) or Register Transfer Language (RTL) specification (“User Verilog/VHDL RTL Design” 812). Libraries are provided describing functional and timing characteristics associated with all library cells that may be implemented on a base wafer, such as a predetermined or prefabricated structured array wafer (“Cell Timing Models (.lib)” 811). The libraries may be accessed by various tools shown later in the flow. The design is then converted to a specific implementation description according to the library and the design specification (“Synthesis” 813). Semiconductor vendor process information such as the number and type of metal layers and via layers, process design rules, and process parameters are provided (“Base Die Description” 814). The die description also includes all die floorplan information associated with implementation as a structured array, i.e. descriptions of SAF tiles. The die description is processed (“Design Create Import Verilog/VHDL” 816) in conjunction with a gate-level netlist produced by synthesis (“Gate-level Netlist (Verilog/VHDL)” 815) resulting in a parsed netlist. Selected improvements are performed, such as buffer deletion, dead logic removal, inverter pair elimination, and constant propagation (“Design Pre-optimization (buffer deletion, dead logic removal)” 817). Then directives to guide the physical design are processed (“Load Floorplanning Constraints (IOs, RAMs, group, region constraints)” 818). In certain usage scenarios the floorplan constraints are used to “lock” selected elements into desired regions of the die. For example IO pads may be assigned to the perimeter, and RAMs may be allocated to specific zones. Core logic may be guided to selected areas or grouped together as desired. In some embodiments the floorplan constraints are provided via one or more scripts (“Place Script; Floorplan Script” 822). Timing performance criteria are then processed (“Load Timing Constraints” 819), in some embodiments according to timing libraries (“SDC Timing Libraries (.lib)” 823). Information in the timing libraries may be according to an SDC format, and includes input arrival times, output required times, false path identification, and multi-cycle path notations. In certain embodiments subsequently locations are determined for all of the elements in the netlist (“Placement” 820), guided by previously provided constraints. Timing performance improvements are then made to effect timing closure (“Buffering Clock Tree Synthesis Timing Driven Buffering/Resizing” 821). Clock tree synthesis strives to meet desired clock skew constraints, and buffer resizing serves to meet user specified timing constraints. Processing then flows (via 824) to output post layout design data (“Export: DEF/Verilog” 831). In certain usage scenarios a format compatible with Design Exchange Format (DEF) is used to facilitate interchange with various EDA tools. The output DEF (“DEF” 832) specifies the structure of the design and all placement information. The output Verilog (“Verilog” 834) specifies the post-layout gate-level netlist. The DEF output is provided along with information describing routing technology (“LEF” 833) to compute interconnect details (“Router” 835). The resultant geometry is output as DEF (“Routed DEF” 836) that is processed (“3D Extractor” 837) along with the routing technology information to determine connectivity and parasitic information (“SPEF” 839). The parasitic information is according to a Standard Parasitic Exchange Format (SPEF). A timing performance check is then made (“Timing Analysis” 840) using the parasitic information, the post-layout gate-level netlist, and device characterization information (“StdCell Library” 838). A correctness check is also made (“Formal Verification” 826) by comparing a pre-layout gate-level netlist (“Pre-layout Gate-level Netlist” 825) with the intended-to-correspond post-layout gate-level netlist. In some usage scenarios the pre-layout gate-level netlist is identical to the netlist output from synthesis. The illustrated EDA flow is an example only, as some of the illustrated operations may be omitted or performed in slightly different orderings according to various embodiments. Manufacture of Devices Designed Via SDI-Directed Techniques Conceptually a structured array architecture is defined to satisfy a plurality of user-specific designs. The architecture is optionally based on a pre-characterized standard cell library. A plurality of user-specific designs are targeted for the defined architecture, and physical layout is generated at least in part based on a SDI-directed place and route flow. An inventory of wafers (or die) built according to the structured array architecture is used as a starting point to manufacture instances of the user-specific designs. Thus a single structured array architecture (and corresponding predetermined wafer inventory) serves to implement more than one user-specific design via a SDI-directed placement and routing. FIG. 9 illustrates an embodiment of selected details of manufacturing integrated circuits, the circuits being designed in part based on SDI-directed design techniques. The manufacturing flow begins (“Start” 901) by receiving objectives for a design or a group of designs (“Goals” 902) along with optional information (“Standard Cell Library” 904) regarding relatively fixed-function elements previously manufactured and characterized according to a selected integrated circuit production facility or “fab”. The received items are processed to determine one or more SAF tiles to be arrayed to form a structured array integrated circuit (“Define Structured Array” 903). The standard cell library information may be used to develop SAF tiles with lower cost than developing SAF tiles from “scratch”. Fabrication images are produced from the structured array design (“Produce Lower Layer Masks” 905). The lower layer masks are combined with starting materials (“Wafers” 906) to produce an inventory of pre-fabricated structured array die (“Fabricate Lower Layers” 907). A first and a second device are designed according to a SDI-driven place and route flow, and the resultant design databases are provided to the flow (“Device 1 SDI P&R Result” 908 and “Device 2 SDI P&R Result” 909). Each of the databases is then used to produce corresponding sets of upper layer fabrication images (“Produce Device 1 Upper Layer Masks” 910 and “Produce Device 2 Upper Layer Masks” 911, respectively). The upper layer masks are used to manufacture (“Fabricate Device 1 Upper Layers” 912 and “Fabricate Device 2 Upper Layers” 913, respectively) one or more integrated circuits according to each of the respective designs, using portions of the previously developed inventory (“Fabricate Lower Layers” 907). The manufactured devices are then tested (“Test Device 1” 914 and “Test Device 2” 915, respectively) and the flow is complete (“End” 999). Computer System Executing SDI-Directed EDA Routines FIG. 10 illustrates an embodiment of selected details of a computer system to execute EDA routines to perform SDI-directed place and route operations. There are multiple sub-systems illustrated including computing and storage complexes (System 1001A and System 1001B) and workstations (local WS 1017B and remote WS 1017C). Similar elements have identifiers using the same numerical base, and a letter suffix is used to distinguish different instances. For brevity, unless there is a notable difference between the instances, only the first instance of similar elements is described. A data processing machine (System 1001A) includes a pair of computational elements (Processors 1014A and 1015A). Each processor includes a Central Processing Unit (CPUs 1010A and 1011A, respectively) as well as working memory (RAMs 1012A and 1013A, respectively). The machine is coupled to a storage array, such as disk 1018A, that includes images of EDA software (SW 1019A) and design database information (DD 1020A). An interconnection resource (Local Area Network LAN 1016) enables local communication between System 1001A, System 101B, and workstation/PC (WS 1017B) enables local users to access the facilities to direct and observe computations. Systems 1001A and System 1001B are also coupled to Wide Area Network WAN 1030, such as a corporate intranet, the Internet, or both. Remote WS 1017C communicates with any combination of System 1001A and System 1001B via WAN 1030. In certain embodiments, WS 1017C has a disk 1018C, that includes images of EDA software (SW 1019C) and design database information (DD 1020C). In some embodiments at least part of the EDA software images may be compressed or encrypted while stored on disk. SW 1019A may include one or more machine-readable executable files corresponding to any combination of processing operations illustrated in FIG. 1, as well as any processing operations performed on behalf or under control of elements in FIG. 1. For example, global placement (such as SDI-directed global placement), legalization, detailed placement, timing closure, and routing operations may be encoded as portions of SW 1019A for execution by System 1001A. Similarly, design data (such as data corresponding to any combination of portions of “Commands and Parameters” 130 and “Working Data” 131) may be stored in portions of DD 1020A. In operation the CPUs (in conjunction with associated RAMs) execute portions of SW 1019A to perform assorted EDA functions. In some embodiments SW 1019A may include routines that are chosen (or optimized) in part to facilitate parallel execution of EDA routines (such as SDI-directed global placement, legalization, detailed placement, and routing) on CPUs 1010A and 1011A. In some embodiments the parallel execution may be carried out on System 1001A simultaneously (or overlapping) with System 1001B (via LAN 1016) such that CPUs 1010A, 1011A, 1010B, and 1011B are operating together to provide a SDI-directed EDA solution for a single user-specific design. The parallel processing is not limited to two machines, nor to machines with multiple internal processors. Rather, the parallel computation may be performed on a collection of processors, however organized or subdivided amongst independent machines. For example, the software may run on a massively parallel supercomputer, or on a network of multiprocessor computers, or on a network of single processor computers. In certain embodiments, each of System 1001A, WS 1017B, or WS 1017C may have an associated removable media drive, represented respectively by drives 1040A, 1040B, and 1040C. The removable media drives are used to load at least parts of the EDA software images, such as those discussed above, from removable media, represented respectively by disks 1045A, 1045B, and 1045C. The removable media and the associated drives can take many forms, including but not limited to optical, magnetic, and flash media, including such media as floppy disks, CD-ROMs, DVD-ROMs, and flash disks. In certain embodiments, WS 1017C transfers at least parts of EDA software images SW 1019C from either or both of System 1001A and System 1001B via WAN 1030. With or without a local EDA software image, according to various embodiments, WS 1017C may interact with either or both of System 1001A and System 1001B for the purpose of locally or remotely executing or controlling any of the global placement (such as SDI-directed global placement), legalization, detailed placement, timing closure, and routing operations, as otherwise taught throughout this disclosure. In various embodiments, WS 1017C selectively has control interactions and/or data transfers (including data related to the design database information) with respect to either or both of System 1001A and System 1001B. In various embodiments, the transfers are selectively compressed or encrypted. At least parts of the EDA software images, the control interactions, or the data transfers, are thus observable as propagated signals at points that include signal observation point 1035C and point 1035A. In various embodiments, the propagated signals selectively include interactions related to enabling and/or licensing of WS 1017C (or a particular user of WS 1017C) to locally and/or remotely execute and/or control any of the EDA operations taught herein. In certain embodiments, an FTP service is made available to WS 1017C for downloading of at least parts of EDA software image 1019C via WAN 1030. In related embodiments, the downloaded software is adapted to be a demonstration embodiment, with either limited functionality or that functions only for a predetermined interval. In other related embodiments, a software key is used by WS 1017C (obtained via WAN 1030 or other means of distribution) to enable or restore functionality of at least parts of the EDA software, whether the EDA software was loaded from removable media 1045C or propagated via WAN 1030. In related embodiments, the management and distribution of the software key is a component of the licensing process. The licensing is not limited to workstations. In an analogous embodiment, at least part of System 1001A and System 1001B are licensed using selective aspects of the above described techniques. In certain embodiments, executing EDA software, as otherwise taught herein, selectively reports license related events via WAN 1030 to license management processes running on at least one designated server. In related embodiments, the reported license related events are evaluated in accordance with predetermined criteria and alerts, reports, control events, and/or billings are selectively and/or automatically created and/or updated. SDI-Based Detailed Placement Embodiments FIG. 11 illustrates an embodiment of an SDI-based detailed placement flow useful in a variety of applications. The SDI-based detailed placement flow may replace and/or augment operations performed after global placement and before routing (such as any combination of processing relating to “Legalization” 203 and “(SDI) Detailed Placement” 204 of FIG. 2). In 1101 a legal global placement is developed (such as via “SDI Global Placement” 202 of FIG. 2). In 1102 nodes are (optionally) prevented from moving between Q-blocks, thus increasing the likelihood that a fitting (i.e. legal) global placement is retained during continued system evolution. In some usage scenarios where circuit density is at or near a threshold of what can be supported in a structured ASIC architecture, the processing of 1102 is invoked. In some usage scenarios where the processing of 1102 is omitted, subsequent legalization processing is used. In 1103 spreading force strengths are increased, and in some usage scenarios the spreading forces are substantially increased. According to various embodiments the spreading forces are increased by any combination of reducing digital filtering of fields sourcing the spreading forces, and increasing spatial resolution of a grid the spreading fields are calculated with respect to. In some usage scenarios the (substantial) increase in spreading forces does not result in (substantial) bulk motion since nodes (such as form-level nodes) are prevented from moving between Q-blocks. In some usage scenarios the (substantial) increase in spreading forces does add energy to the system, and various techniques for changing the ratio between kinetic and potential energy of the system may be employed (as described elsewhere herein). In some usage scenarios processing in 1103 serves to overcome tight packing of form-level nodes that causes local density of the form level nodes (on relatively short spatial length scales) to exceed slot density (i.e. supply) of the underlying SAF. In some usage scenarios the exceeding of supply increases effort required by a slot assigner to discriminate between alternate slot assignments. By spreading out the form-level nodes and reducing large density fluctuations on short spatial length scales, the form-level nodes within the Q-block are driven farther apart, and thus closer to coordinates of ultimate slot assignments. In some usage scenarios the reduction of density fluctuations serves to reduce dislocation during detail slot assignment, thus improving quality of the detail placement overall. In 1104 morphing is optionally repeated, with new target locations for form-centers. In some usage scenarios nodes demanding a resource may be unevenly distributed in a region, and thus some of the resource-level nodes are moved a comparatively long distance to reach a slot. The movement results in “cut inflation”, where nets are forced to be routed over relatively longer distances and thus consume more routing resources than were anticipated by the form-level placement. The cut inflation results in decreased routability. The cut inflation may be overcome by the optional morphing, to improve the balance between spatial distribution of resource slots and nodes. Nodes are then moved shorter distances during slot assignment, reducing cut inflation and routability degradation. In 1105 the netlist is elaborated with resource-level nodes and nets spanning pins on the resource-level nodes (see the discussion relating to FIG. 12A and FIG. 12B). Forces are included to tie resources to respective parent forms. In some embodiments information relating to the resource-level nodes (and associated spanning nets) is retained in extended data structures to facilitate SDI-based processing of the resource-level nodes. In 1106 forces and interaction coefficients are initialized to relatively low values for the new resource-level elements of the combined (i.e. elaborated) netlist. Integration is then resumed in 1107. The resumed integration is according to the forces and interaction coefficients for the new elements in addition to the forces and the interaction coefficients “inherited” from the global SDI-based processing. In some usage scenarios using the new and inherited forces and coefficients together results in disentanglement of the resource-level nodes now present in the netlist. Enabling the resource-level nodes to move independently of each other provides a context for resources to move left (or right) or up (or down) with respect to sibling resources of the same parent form. The movement of the resource-level forms enables more efficient slot assignments otherwise indistinguishable when only the center of the parent form is examined. In 1108 integration (i.e. time evolution of the system) is stopped according to selected criteria. In some embodiments dampening effects are increased to drive the system toward a new state reflecting separation of resource-level nodes and to prevent or reduce thrashing. In some embodiments the dampening effects are auto-regulated. The selected criteria may include any combination of a number of integrator steps, an amount of “system time”, system kinetic energy (i.e. temperature) falling to a threshold value, system kinetic energy falling by a threshold percentage with respect to an initial value, and system kinetic energy falling by a threshold percentage in a single time step. The number, the amount, the threshold value, and the threshold percentages may be predetermined or programmatically varied according to various implementations and usage scenarios. In 1109 all Q-blocks are processed. In some embodiments the processing for each Q-block is according to functions described elsewhere herein with respect to FIG. 13. In 1110 processing relating to 1109 is repeated until stopping criteria are met. In some embodiments the criteria include full placement of all resource classes. In some embodiments processing then continues according to functions described elsewhere herein with respect to FIG. 14. FIGS. 12A and 12B illustrate concepts relating to an embodiment of netlist elaboration. FIG. 12A illustrates a portion of a system with three form-level nodes located on computational grid 1210 and coupled by a plurality of form-level nets. FIG. 12B illustrates the system of FIG. 12A with resource-level nodes (corresponding to resource-level forms) for each of the form-level nodes “added” to the system. Also illustrated are connections between resource-level nodes and corresponding parent nodes, as well as resource-level nets. The parent connections and resource-level nets are representative of corresponding forces and interaction coefficients that are added to the system as a result of elaboration and in preparation for SDI-based detailed placement time evolution. The resource-level nodes and nets may be retained in extended data structures for the SDI-based processing. FIG. 13 illustrates an embodiment of detailed placement of a Q-block. In 1301 priority of each resource class in a Q-block is assessed, based on a combination of factors relating to resource supply and consumption. Less supply makes for higher priority, and more consumption makes for higher priority. Note that prioritization results naturally vary from one Q-block to another, as nodes (demand) and available slots (supply) vary from one Q-block to another. Processing according to 1310, 1320, and 1330 is then performed for each resource class in order according to the resource class prioritization. In 1310 slot dˆ2 optimized slot assignment for nodes of the respective resource class is performed via one or more techniques identical to or similar to processing associated with elements illustrated or discussed with respect to FIG. 6 (such as “Pairwise Interchange” 603). In some embodiments the slot assignment is performed using an implementation dependent technique. In 1320 resource-level macros of the respective resource class are assigned to computed (or destination) slots. The assignments are then “fixed” (i.e. prevented from moving or being reassigned). According to various embodiments the fixing may be via any combination of a variety of techniques. The techniques include: Instantaneous enactment, i.e. a node is moved directly to the destination slot and locked; Gradual enactment; i.e. a node is propelled toward the destination slot using a slow but overwhelming force, stronger than all other forces acting on the node, so that the node reaches the destination slot in an adiabatic motion over some reasonable number of timesteps and is locked there; and Direct parametric motion; i.e. a line is drawn from the current position of the node to the destination slot, and the node is moved directly along the line toward the destination slot over a series of timesteps and is locked there. In 1330 remaining unfixed elements are optionally enabled to relax according to new coordinates corresponding to the destination slot assignments most recently made in 1320. In some embodiments (such as various embodiments using instantaneous enactment) processing in 1330 is performed. In some embodiments (such as various embodiments using gradual enactment or direct parametric motion) processing in 1330 is skipped. FIG. 14 illustrates an embodiment of an additional pass of detailed placement of a Q-block. Processing according to 1410, 1420, 1430, and 1440 is performed for each resource class in order according to the resource class prioritization determined in 1301 of FIG. 13. Each resource class is unfixed in turn to enable additional relaxation. In some usage scenarios a plurality of iterations of processing of all resource classes according to FIG. 14 is performed. Unfixing each resource class enables higher priority resource classes (i.e. classes processed ahead of other classes) to relax with respect to lower priority resource classes (i.e. classes processed behind other classes). Additional Morphing Embodiments In at least some structured ASICs the supply of fundamental hardware resources is predetermined and fixed. Careful apportionment of netlist nodes into function-realization-entities (forms) can help to improve the quality of the physical solution of the EDA flow. However, size and performance constraints cause the form selections of different nodes in the netlist to be coupled, resulting in an extremely complex and thus potentially expensive computational optimization problem. A procedural approach to generating a solution includes a technique making use of Integer Linear Programming (ILP). Illustrative embodiments for circuit placement are described. A schema for representation of a circuit netlist when nodes of an initial (e.g. synthesis- or schematic-derived) gate level netlist are interchangeable with functionally equivalent alternatives implemented using different hardware resources is used. Herein, each functionally equivalent realization is called a “form”, and the initial gate level netlist is called the form-level netlist. Exchanging a form instance in the form-level netlist with a functionally equivalent alternate form is herein called “morphing”. FIG. 12A illustrates a form-level net of form-level nodes overlaid on a computational grid. FIG. 12B illustrates one type of view of an elaboration of the form-level net of FIG. 12A to include resource-level nodes in a resource-level net. FIG. 15A illustrates a form of the form-level net of FIG. 12A. In this view the resource-level nodes are shown internal to the form. FIG. 15B illustrates another form that uses different resources to implement the same function as the form of FIG. 15A. In at least one embodiment, the form of FIG. 15B is substituted for the form of FIG. 15A through a morphing process. In a structured ASIC, the supply of hardware resources is predetermined and fixed. The optimal selection of implementation form for each node in the form-level netlist is a complex problem involving many coupled considerations. For example, certain hardware resources in a structured ASIC might be faster than others, but if all form-level nodes were morphed into forms that utilize the faster resource, then the total silicon area required to implement a circuit could be greater than otherwise necessary, thus increasing cost of manufacture. A denser placement may be obtained if the form-level instances in the netlist are morphed amongst available forms so aggregate demand for each resource type across all form instances in the netlist follows the same proportional relationship as the supply thereof in the structured ASIC architecture being used to implement the circuit. However, since in such an apportionment, many form instances will be implemented using forms that require slower hardware resources, the circuit may perform slower overall. Careful apportionment of the forms among the nodes of the netlist to optimize overall performance of the circuit is important. Each change of a given form instance from one implementation form to another results in a change to timing characteristics of all logic paths through the affected node, hence providing another coupling pathway in the form determination process. Similarly, if resource exhaustion forces a node to be implemented using a form such that the nearest available implementation resources are far from the ideal location of the node, then routability degradation may occur. There are many uses of morphing in structured ASIC EDA. The following list of examples is provided for illustration only, and should not be taken as limiting. As one illustrative example, consider the case of a netlist that is to be placed in a structured ASIC logic array instance. Knowledge of whether the netlist can be packed to fit into the available resource supply of the specified structured ASIC is desired. A simple tabulation of the resources demanded by the forms in the initial gate level netlist can be performed and compared to the supply of resources in the structured ASIC logic array instance. FIG. 16A illustrates the supply and demand for resources R1 through R6 corresponding to target functions of an integrated circuit design having a first selection of forms for the target functions. For at least some of the resources, the demand exceeds the available supply. However, even if the demand for any resource exceeds supply in the structured ASIC logic array instance, then a fit may still be possible. It may be possible to morph some or all of the nodes in the form-level netlist by exchanging selected form instances with functionally equivalent alternate forms, to relieve the over demand for certain resources while increasing the demand for other underutilized resources. FIG. 16B illustrates the supply and demand for resources R1 through R6 for the same target functions as for FIG. 16A, but using a second selection of forms for the target functions obtained by morphing certain forms to use different resources. For each of the resources shown, the demand is less than or equal to the supply. In this way, a morphing operation can yield a determination of the feasibility of fitting a netlist into a structured ASIC logic array instance. As another illustrative example, consider the case of a netlist that is to be placed into the smallest possible accepting logic array instance of the structured ASIC. In this situation the size of the structured ASIC is not predetermined, but is to be an output of the netlist packing optimization problem. Possible approaches include: A) A succession of structured ASIC logic array instances of different sizes are individually evaluated using the fit-checking procedure described in the preceding example. The smallest structured ASIC logic array instance that is large enough to hold the netlist is the result. B) Morph the form-level netlist until the stoichiometric ratios of the resources demanded by the forms matches as nearly as possible with the stoichiometric provisioning proportions in the structured ASIC. Then the ratio between the corresponding elements in the resource demand versus provisioning yields the required logic array size. In yet another illustrative example, consider the case of the placement of a netlist within a specified structured ASIC logic array instance. In this case, in addition to determining if a netlist can fit, a complete final placement is sought, such that all resources consumed by forms of a form-level netlist are uniquely assigned to resource “slots” in the structured ASIC logic array instance. One approach is to divide available area into abutting blocks, and then attempt to find a morphing solution that fits a respective portion of the netlist over each block into the respective resource complement of the respective block. As with the netlist fit-checking operation described above, there may be an initial imbalance between the resources demanded by the forms and the structured ASIC logic array supply in a given region that can be relieved through morphing. Only a subset of the nodes in the netlist participate in the morphing operation, and only a portion of the resources of the structured ASIC logic array instance are available for utilization. The block morphing operation is performed on the subset of the netlist that is contained within each of the blocks. The blocks need not be of uniform shape or size. Of course, embodiments such domain decomposition and netlist subsection morphing are not the only approaches to placement generation. As long as the whole netlist is morphed to fit within the resources of the whole structured ASIC logic array instance, there will be some way that the resources of the form instances in the netlist could be assigned to resource slots. As an additional illustrative example, consider the case of placement of a netlist into a dynamically sized structured ASIC logic array instance, where the final size of the logic array is determined simultaneously with generation of a legal placement. Such a facility might work by “spreading” the netlist until nodal density fell to a point where block-based morphing (as described above) was successful for all domains containing circuit elements. The size of the final fitting configuration determines the size of the structured ASIC logic array to be used for the netlist. This example is distinct from the minimum logic array size determination example above, in that the former represents a theoretical maximum packing density determination, where all the netlist form-level nodes participate in the morph, whereas in this case there are many independent morphing problems where a reduced subset of the netlist nodes participate in the morphing operation. The size of the logic array instance that can be obtained in this way will in general be lower bounded by the former “theoretical maximum density” logic array size described in the earlier example. In general, the fewer the number of form-level instances that participate in a morphing operation, the less space-efficient the solution will be. As an additional illustrative example, consider the case of a placement flow that aims to generate a placement of a netlist using iterative refinement of morphing regions. In this scenario, processing starts with a structured ASIC logic array instance size known to be big enough to hold a morphed version of the netlist (at least as big as the minimum theoretical size produced by the logic array size minimization example in the previous section). A morphing window is defined, initially to be the size of the full structured ASIC logic array instance. The netlist is globally placed within the window using any available global placement or partitioning technique and morphing operations are attempted in subdomains (or subwindows) of the (previous) morphing window. The subwindows may be constructed by bisection of the enclosing window, or by any other suitable subdivision technique. When the global placement has evolved to the point that each subwindow is morphing soluble, the netlist nodes are constrained to stay within the subwindows, and the subwindows themselves are taken to define a reduced spatial domain for further global placement or partitioning refinement. In this way, the process proceeds by recursive subdivision of morphing windows, until some limiting cutoff criteria is reached. For example, the process might terminate when the morphing windows reach a size of 10 nanometersˆ2, or any other similar stopping criteria. Note in particular, that spatial resolution of the recursively refined morphing window grid is not required to be spatially uniform. Indeed, nonuniform spatial resolution refinement grids may be of special utility in situations with complex floorplans. Morphing Techniques Now consider a detailed description of some specific techniques for implementing morphing according to various embodiments. Morphing Techniques: Interchange Morpher An illustrative interchange morphing (problem) solver uses three specification components: 1) A library. The library is a statement of available forms, the function each form implements, and quantity of each resource that is utilized by each form. 2) Netlist nodes, each node of some particular initial form type. The netlist nodes may be a subset of the netlist. 3) Capacity of resources provided by the structured ASIC. The capacity may be a subset of total resources available for placement. In some usage scenarios the capacity is specified as an array of integers, indexed by an identifier of the resources in the structured ASIC logic array architecture. Interchange morphing proceeds in stages, as follows: 1) Assess initial demand for resources by accumulating demand for each resource type by the form of each participating node. In pseudo-code: for_each node n do: f=n.form for_each resource r do: footprint(r)=footprint(r)+library.resource_demand(f,r) If footprint(r)<=capacity(r) for each r, then the nodes fit on entry and no additional morphing is required in order to achieve a fit. In some usage scenarios additional morphing may be desirable, since there are many factors of interest besides just placement feasibility. 2) Take forms without alternates. Depending on the specific construction details of the structured ASIC library, there may be forms with no alternates, i.e., functions with only one way to be implemented in the structured ASIC architecture (that is specified in the library). Forms without alternates will not be morphing since there are no interchange possibilities, so the forms without alternates are taken as is. One way to do this is to remove the forms from the morphing participation set, and remove resources consumed by the removed forms from the resource capacity vector. Alternatively other bookkeeping strategies may be used. 3) Register balancing. In some structured ASIC architecture configurations, the forms implementing sequential (register) functions are restricted, having much reduced morphability (fewer alternate implementation forms) compared to combinational forms. For example, there may be only one or two sequential resources (flip flops) in the structured ASIC architecture, from which the sequential forms can be built. Often there is only a single sequential form per sequential resource type, for the sequential functions. In contrast, it is not uncommon for combination functions to have a dozen alternate implementation forms, with corresponding resource demand touching each non-inverter resource type. Because of the reduced implementation flexibility, it may be desirable to resolve sequential balancing next. This can be done, for example, by the following procedure. Score sequential nodes according to respective footprints onto oversubscribed resources. Sort the nodes by the scores, so the higher scoring nodes are considered first for morphing into alternate forms. For each sequential node with a footprint onto an oversubscribed resource, score each respective alternate form according to an objective function, and select the best scoring form. If the selected form is different from the current form, then a morph is performed. After each morph, check to see if the sequential resources have been brought into alignment with the resource supply. If so, then exit the register balancing processing, and otherwise continue to the next node. Aspects of certain objective functions will now be detailed. Other objective functions may also be used, thus these embodiments are merely illustrative and not limiting. For scoring sequential forms, founding some usage scenarios it may be useful to accumulate 1 (one) for each combinational resource utilized, plus 10 times the number of any oversubscribed resources used by the form. Lower scores are thus preferable. For combinational forms, in some usage scenarios it may be useful to accumulate for each resource ‘a’ utilized by the form, the quantity: double sa=(100.*cfpa*tfpa)/capacity—a*(tfpa>capacity[a]?(100.*tfpa/capacity—a): 1.); where cfpa is the form footprint onto resource a, tfpa is the total footprint onto resource a if the form were to be chosen, capacity[a] is available supply for resource ‘a’ in the current morphing context, and capacity_a is the same as capacity[a], unless capacity[a] equals zero, in which case capacity_a is 0.01 (to avoid division by zero). The formula has the property of heavily costing demand for oversubscribed resources, and of accentuating the cost of using forms with a footprint onto resources that are provided in smaller proportions by the structured ASIC architecture. In some embodiments alternate mathematical formulas provide similar behavior. 4) Morph combinational nodes. Similar to register balancing, remaining as yet unmorphed non-sequential (e.g. combinational) nodes that have a footprint onto an over subscribed resource are identified. The alternate forms are scored according to the objective function, and the best (lowest cost) morph selected. In some usage scenarios the combinational node morphing results in a collection of nodes that have been morphed to fit within a resource supply of a specified problem context. In some usage scenarios the combination node morphing results are insufficient, and the following additional procedures may be optionally invoked. 5) A morph away from an oversubscribed resource may be blocked because alternate forms all have a footprint onto some resource that will become oversubscribed if the morph is taken. Thus ways to “make room” for forms that will be coming out of oversubscribed resources and impinging upon different resources than a starting configuration are searched for. One technique is to “extract” inverter forms. Since the inverter function can be implemented with essentially any combinational resource, there is really no danger of an inverter being unable to be reinserted, if there is room. The technique comprises extracting inverters, scoring forms with a footprint onto oversubscribed resources using the objective function, and then taking the best scoring alternate form. Finally, the inverters (the forms implementing the inverter function) are added back in, morphing as necessary to attempt to achieve a fit. In some usage scenarios 5) is run after the procedures 1 through 4, although this is not required. 6) Building on 5), morphing may be inhibited whenever a destination resource is fully occupied. Thus in addition to extracting the inverters, any forms that impinge on almost-full resources are also extracted. The extracting opens up additional space so that when iterating through the forms impinging on over-subscribed resources, there is more room in resources that previously appeared full. Then the full set of removed nodes are reinserted, morphing as needed. In some usage scenarios 6) is run after 5), but this is not required. Morphing Techniques Integer Linear Programming Based Morphing Some morphing embodiments use integer linear programming. A linear program is constructed comprising a system of equations and constraints specified over a set of state variables representing the number of forms of each form-type. The formulation includes: 1) Function instance conservation constraint equations 2) Resource capacity constraints 3) An objective function The independent system variables are taken to be the number of each form to be utilized. The system variables are constrained to be non-negative integers. The count of instances of a given form type cannot be either fractional (a given netlist node is implemented exactly and entirely using one specific form in any valid morph state) or negative. Once the constraint equations and the objective function are specified, the ILP solver returns with the number of each form to be utilized, which optimizes the objective function and satisfies the constraints. Of course, it is possible that no solution exists, if for example, the number of form instances assigned to a region is so great that the forms cannot be packed in, or if there is inadequate morphability in any of the functions. If there is no solution, then the ILP solver returns a status indicating that no solution could be found. The function instance conservation constraint equations state that the result will have the same number of instances of each function type as were in the original configuration of the subset of the netlist participating in the morph. Stated another way, the intent of morphing is to select alternate forms implementing the same circuit function, so the action of the morpher on a set of nodes should preserve the number of instances implementing each function. Within a function, the distribution of nodes implemented in different forms can change, but the total number of nodes in all the forms implementing the function is the same in the output as in the input. Morphing per se does not change the Boolean algebraic structure of the form-level netlist. (Other optimization technologies unrelated to morphing do that, and use of morphing does not preclude use of the other technologies.) For example, suppose that the number of form instances implementing the NAND2 function is 5, apportioned on input as 3 form instances using form NAND2—1 and 2 using form NAND2—2, and that the number of form instances implementing a MUX4 function is 7, apportioned as 3 form instances using MUX4—1, 2 using MUX4—2 and 2 using MUX4—3. Further assume that the state variables x_0, x_1, x_2, x_3, x_4 represent the number of form instances of the forms NAND2—1, NAND2—2, MUX4—1, MUX4—2 and MUX4—3 respectively. Then the following two constraint equations would be among the set of function instance conservation equations: 1*x—0+1*x—1+0*x—2+0*x—3+0*x—4+0*x—5+ . . . =5 0*x—0+0*x—1+1*x—2+1*x—3+1*x—4+0*x—5+ . . . =7 The resource capacity constraints are inequalities that state that the resources utilized by a given form allocation may not exceed resources that are available. There is one respective constraint inequality for each resource in the structured ASIC architecture. In the respective inequality constraint for each resource, the coefficient of each state variable is the number of that resource consumed by the corresponding form. The right hand side is the capacity of that resource in the current region context. For example, consider a morphing problem for a structured ASIC architecture containing NAND2, NOR2 and INV resources (among others). There are INV_INV, INV_ND2 and INV_NR2 implementing an inverter function each using one of the INV, NAND2 and NOR2 resources respectively. There is a form XNOR2—1 implementing an XNOR2 function using three NAND2 resources and one NOR2 resource. There is a form XNOR2—2 implementing an XNOR2 function using two NAND2 and two NOR2 resources. In the current region there are 400 INV, 100 NAND2, and 150 NOR2 resources. Then the resource capacity constraints would include terms like these: 1*x—0+1*x—1+1*x—2+0*x—3+0*x—4+ . . . <=400 0*x—0+0*x—1+0*x—2+*x—3+2*x—4+ . . . <=100 0*x—0+0*x—1+0*x—2+1*x—3+2*x—4+ . . . <=150 where x—0 represents the number of INV_INV forms, x_1 the number of INV_ND2 forms, x_2 the number of INV_NR2 forms, x_3 the number of XNOR2—1 forms and x_4 the number of XNOR2—2 forms. Some structured ASIC architectures have resources that can be reconfigured to switch between different primitive Boolean functions. For example, in some structured ASIC architectures, a mask reconfiguration might allow an abstract resource to be switched between implementing either a NAND2 function or a NOR2 function. Morphing support for such architectures can be accommodated in variations of the integer linear programming formulation by including combination constraint inequalities to constrain the sum of forms implemented using the reconfigurable resources to be no larger than the total possible. For example, posit a structured ASIC architecture such that within a given region there are 100 NAND2 resources, 100 NOR2 resources, and 100 NAND2/NOR2 combination resources. Label the NAND2 resource 0, the NOR2 resource 1, and the NAND2/NOR2 combination resource 2. Further, represent the footprint of form i onto resource j as R_ij and the supply of resource i as S_i. Then constraint inequalities would include terms like: R—00*x—0+R—10*x—1+R—20*x—2+ . . . <=S—0+S—2 R—01*x—0+R—11*x—1+R—21*x—2+ . . . <=S—1+S—2 (R—00+R—01)*x—0+(R—10+R—11)*x—1+(R—20+R—21)*x—2+ . . . <=S—0+S—1+S—2 The above formulation enables exploration of solutions where the combination resources are allocated flexibly between either resource behavior, but simultaneously excludes solutions that oversubscribe the simple plus combinational resource supply. Morphing Techniques: Objective Function In some usage scenarios an ILP solver package allows a user to specify an objective function of the system variables to optimize, as there may be many solution vectors that satisfy the various constraint equations. Without the ILP solver, the best choice of the many available solutions may not be apparent. An objective function is a function specified as a linear combination of the system state variables. The ILP solver then returns the best solution found, as measured by the objective function. That is, of the range of solutions satisfying the constraint equations, the chosen solution will be the one that maximizes the objective function. F=sum—iO—ix—i where i ranges over the number of variables in the system, x_i is the ith system variable, and O_i is the coefficient to be applied to the ith system variable. More specifically, 0<=i<N_forms, where N_forms is the number of forms in the library and x_i is the number of the corresponding form in the solution. One particularly useful objective function to use is a so-called “form efficiency”. The form efficiency measures efficiency of implementation of each form in terms of respective Boolean computational work that the respective form performs divided by a similar measure of Boolean computational work that could be performed using resources consumed implementing the respective form. In some usage scenarios the efficiency of a form varies between 0 and 1, although the normalization is immaterial to the optimization problem. Other embodiments use optimization objectives other than form efficiency. Morphing Techniques Software Implementation An illustrative usage scenario of form morphing follows. The structured ASIC logic array is divided into regions, and a global placer apportions circuit nodes to the various regions. A morphing controller function then cycles through the regions, identifies respective resource capacities and respective netlist nodes contained within each region, and calls the morpher, passing in the resource capacities, nodes (with the current form assignments), possibly a choice of objective function, and possibly also an indication of the priority of the nodes, and possibly also a function for evaluating the suitability of any given form for any given node. The morpher evaluates the number of nodes implementing each function present in the set of participating nodes as respective function instance counts according to a library. The function instance counts, along with the resource capacities, are used to formulate the system of equations and inequality constraints, as described above. The coefficients of the objective function are supplied, and the ILP solver is invoked. If a solution is found, then the resulting quota of forms (i.e., a particular distribution of form types determined by the ILP solver) is apportioned to the participating nodes in some manner. One illustrative example technique is to pass through the nodes, and test to see if the full quota of the respective current form has been reached yet. If not, take the form, and move to the next node. If so, morph this node to the next not-yet-exceeded form type within its function group. An additional illustrative, but not limiting, example technique for apportioning forms is as follows. Order input nodes according to a priority indicator supplied by a caller. Assign each node to a “preferred” form type (for example, whatever form type the node was assigned by the tool (e.g. a timing-driven synthesis tool) that produced the original form-level structural netlist), if available. If unavailable, then assign to one of the other forms in the function group (e.g. a lower or higher drive strength logically equivalent form). An additional illustrative, but not limiting, example technique for apportioning forms is as follows. When a preferred form quota for a node is exhausted, then instead of assigning the node, push the node back onto a queue for subsequent consideration. After all nodes have been visited once, and either assigned or queued, the queue of blocked nodes is reprocessed. Each node of the queue is assigned any of the available alternate forms in a corresponding function group. An additional illustrative, but not limiting, example technique for apportioning forms is as follows. Use the supplied evaluator function to evaluate the form-ranking on a per node basis, thus enabling factors outside the scope of the ILP formulation to affect determination of the apportionment of the quota of forms developed by the ILP based morpher. In other words, the morpher is responsible for determining a fitting set of form quotas, but other systems or techniques are responsible for apportioning available forms based on more detailed per-node considerations. For example, timing critical path nodes may receive special treatment. Path-Based Timing Force Embodiments Timing Driven Force Computation Timing driven SDI-based placement uses timing forces to systematically influence and optimize timing performance of a placement of elements such as in a design for an integrated circuit. In some embodiments timing characteristics of a circuit are modeled in a timing graph from a time-evolving placement and timing forces are applied by a placement engine as a feedback mechanism. A timing graph may be a Directed Acyclic Graph (DAG) that has nodes that represent pins of a circuit netlist (e.g. provided by a user of the engine and an associated design flow) and edges that represents timing arcs within a library cell and interconnections of the netlist. The timing forces are applied in conjunction with net connectivity forces and spreading forces to improve placement quality as measured by circuit timing performance and routability. One approach for modeling timing force for use in a timing driven SDI-based placement flow is known as a Path-Based Timing Force (PBTF) model. PBTF heuristics apply proportionate timing forces on each node (or element) of various critical paths, so that when spreading forces are applied according to each critical path, the elements are pushed away or held together based on respective contribution to overall circuit performance. In various embodiments of a PBTF system, any combination of factors may be used in determining timing force on an element. The factors include: Critical Paths influence Factor (CPF); Drive Resistance Factor (DRF); and Stage Delay Factor (SDF). Critical Paths influence Factor (CPF) CPF models contributions of a node to all or any portion of critical paths of a circuit. In various embodiments of a PBTF model usage scenario a timing driven placement seeks to improve any combination of the Worst Negative Slack (WNS) and the Total Negative Slack (TNS) of the circuit. Contributions of a node to the critical paths of the circuit are accounted for to improve the TNS of the circuit. FIG. 17A illustrates an example circuit with a plurality of critical paths. The critical paths include: Path 1, P1={N0, N2, N3}; Path 2, P2={N0, N2, N4}; Path 3, P3={N1, N2, N3}; and Path 4, P4={N1, N2, N4}. Node N2 is common to all the paths, while all the other nodes are present in two of the four paths. Thus in some embodiments a CPF computation for node N2 will be higher than CPF computations for the other nodes. In some usage scenarios all critical paths of the circuit are explicitly enumerated. In some usage scenarios not all critical paths of the circuit are explicitly enumerated, since there are an exponential number of timing paths, and CPF modeling builds a heuristic based CPF model for each node of a timing graph. A CPF score is computed by topologically traversing nodes of the timing graph in forward Depth-First-Search (DFS) order and reverse DFS order. Two scores are computed for each node: transitive FanIn CPF (FICPF) and transitive FanOut CPF (FOCPF). The respective CPF score of each node is the product of FICPF and FOCPF. FICPF is computed during the forward DFS traversal as a sum of FICPFs of all immediate predecessor nodes of a node if the respective predecessor node is a critical node: node—FICPF=Sum (critical fanin—FICPF). Similarly, during reverse DFS traversal, an FOCPF of each timing graph node is computed as a sum of FOCPFs of all immediate successor nodes if the respective successor node is a critical node: node—FOCPF=Sum (critical fanout—FOCPF). Then each node CPF score is computed by multiplying the respective FICPF and the respective FOCPF: node CPF score=node—FICPF*node—FOCPF. CPF is then normalized by dividing the CPF score by the maximum CPF of the timing graph: normalized_node—CPF=(node CPF score)/Max (node CPF score). (Eq. 1) FIG. 17B illustrates example computations relating to an embodiment of CPF scoring. Tuples in the figure represent (FICPF, FOCPF) pairs, and underlined numbers represent slack on each node. Drive Resistance Factor (DRF) DRF models contributions of each node on a critical path based on drive resistances of node drivers. In some usage scenarios drive resistance of a node driver is a significant delay contributor to overall path timing. In one modeling equation that considers first-order effects, stage delay of a gate is computed as follows. gate delay=Ti+Rd*Cl; (Eq. 2) where Ti: intrinsic delay of the gate; Rd: drive resistance of the gate; and Cl=interconnect capacitance+pin capacitances (i.e. total capacitive load on the output of a gate). In some embodiments pin capacitances are fixed (or unchanged) during timing driven placement, and thus the timing driven force model is directed to influence interconnect capacitance. According to Eq. 2, improving the product of drive resistance and total output load tends to improve stage delay of a critical path node. The product may be improved by arranging for drivers with relatively higher driver resistance (Rd) to drive relatively lower capacitive loads, resulting in drivers having relatively low driver resistance (such as some drivers on critical paths) driving higher capacitive loads (such as relatively long wires). In some usage scenarios an incremental delay cost associated with driving a “stretched” wire with a strong driver is less than with a weak driver. FIG. 18 illustrates an embodiment of a cascade of buffers of increasing drive strength (i.e. decreasing drive resistance). Five levels of buffer are illustrated with relative drive strengths of x1, x2, x4, x8, and x16 (i.e. each stage provides a factor of two more drive than the preceding stage). Nodes driven by the buffers are illustrated respectively as N1, N2, N3, N4, and N5. Overall delay of the path illustrated in FIG. 18 is minimized if all the logic levels have equal delay. Ignoring intrinsic gate delays, the delay for each element of the path is balanced by equalizing respective products of Rd*Cl. Since Rd(x1)>Rd(x2)>Rd(x4)>Rd(x8)>Rd(x16) the PBTF system attempts to maintain the following relative capacitive loading ordering: Cl(x1)<Cl(x2)<Cl(x4)<Cl(x8)<Cl(x16). Since Cl is directly proportional to wire length, and higher timing force tends to result in shorter wire lengths, timing forces are made proportionate to drive resistance. Relative DRF is normalized by dividing a respective DRF weight of each node by the DRF weight of the node having the least drive resistance: node DRF=(node—DRF_weight)/Min(node—DRF_weights of all nodes) (Eq. 3) where node_DRF_weight=Drive resistance of the driver gate for the node under consideration. Stage Delay Factor (SDF) Stage Delay Factor (SDF) models stage delay contributions of each driver on a critical net (or net on a critical path) and accounts for the maximum path length of each load pin on the critical net. The SDF combines stage delay and maximum path length factors to assign an SDF force component to each load pin. An SDF force is proportional to the maximum path length associated with the load pin. The SDF is computed as follows: SDF Factor=dcoeff*exp(lpwpd/min_cycle−1) (Eq. 4) where lpwpd=load pin: worst path delay; min_cycle=clock period delay of the clock controlling the net; and dcoeff=driver stage delay coefficient. The dcoeff is computed as follows: dcoeff=(dgsd/dpwpd)*path_levels where dgsd=stage delay of the driver gate; dpwpd=driver pin: worst path delay; and path_levels=number of logic levels in the path. Load pin: worst path delay is computed as follows: lpwpd=AT(load_pin)+clock_cycle−RT(load_pin) Driver pin: worst path delay is computed as follows: dpwpd=AT(driver_pin)+clock_cycle−RT(driver_pin) where AT: Arrival time; and RT: Required time. FIG. 19 illustrates example computations relating to an embodiment of SDF calculation. In the figure: lpwpd(L1)=12; lpwpd(L2)=11; lpwpd(L3)=7; dpwpd=12; clock_cycle=10; dgsd=1; SDF(L1)=dcoeff*exp(12/10−1); SDF(L2)=dcoff*exp(11/10−1); and SDF(L3)=0. A stage delay of a driver gate is the sum of the driver gate delay and the interconnect wire delay that is driven by the driver. The driver gate stage delay discriminates the load based on criticality by factoring in the worst path delay of the load pin. If a load pin is part of a slower critical path, then a higher force coefficient is associated with the load pin than a load pin that is part of a relatively faster critical path. The exponential term provides discrimination between two critical paths of unequal lengths. For example, if a first critical path is missing by a target by 2 ns while a second critical path is missing the target by 1 ns, then a higher multiplying factor is associated with the first path (compared to the second path) due to the exponential term. Thus critical paths with worse violations are weighted more. Bounding Box Based Pin Force In some embodiments timing forces are not applied in association with non-critical loads that fanout from a critical driver, thus enabling some relaxation of some (non-critical) loads so that more critical load pins of a net may be pulled closer to the driver. In some embodiments timing forces are applied for non-critical pins, if the pins form any portion of a bounding box of a critical net. A bounding box is defined as a rectangle around all the pins of a net. If a non-critical pin is on the edge of the bounding box, then an attractive force is applied to the load pin, thus in some cases reducing total interconnect capacitance (or at least preventing an increase in capacitance). Path Based Timing Force A first variant of a path-based-timing-force is: PBTF1=CPF*RDF+SDF where CPF: Normalized_node_CPF (as in Eq. 1); RDF: Normalized_node_DRF (as in Eq. 3); and SDF: Normalized_node_sdf (as in Eq. 4). A second variant of a path-based-timing-force is: PBTF2=CPF*RDF+RSF where CPF: Normalized_node_CPF (as in Eq. 1); RDF: Normalized_node_DRF (as in Eq. 3); RSF: Normalized_node_RSF; and Normalized_node_RSF=node_slack/Minimum slack of timing graph. Relative-Slack-Based Timing Force Embodiments The SDI technique of optimizing chip placement relies on a variety of forces affecting nodes in a dynamical fashion, integrated forward in time. These forces are chosen to simultaneously improve metrics that constitute a desirable placement, including routability and timing performance, while achieving a physically realizable (legal) configuration. An approach to timing-driven placement is described in what are referred to herein as “relative slack” embodiments. Relative slack embodiments provide improved results (in both absolute performance as well as numerical behavior) in some usage scenarios. In a first illustrative, but not limiting, class of relative slack embodiments forces affecting pins on a critical path (as well as pins on shared nets) are increased or decreased in an incremental fashion, rather than being directly calculated by a timing kernel. In the first class of embodiments, pin-to-pin forces (so-called timing-based or timing-driven forces) affecting nets (e.g. timing-critical nets) are governed by a force law equation having a linear increase with distance (Hooke's law) and a driver-to-load connectivity model. Other classes of relative slack embodiments may employ any arbitrary functional variation with distance, as well as alternate connectivity models. A set of weights governing the timing-based force attraction are periodically updated, and adjusted in to result in successively better relative node configurations with regard to overall circuit performance. Relative slack embodiments assume existence of a timing kernel that is called during an SDI run to provide relative slack data used in updating the timing driven forces. Specific details of the timing kernel implementation are irrelevant since only r data from a timing graph and propagated pin slacks analysis are needed. The frequency of update can be controlled in a variety of ways: e.g. at regular timestep intervals, in response to a triggering event (dynamical or otherwise), or in response to external (user, script, or graphical) input. Each update provides a “snapshot” of the critical path analysis for every net and pin in the system at that moment of time. The relative slack as calculated for each pin, as well as the position of connected pins (to handle boundary box effects as noted below), results in an adjustment in the “timing weight” associated with each pin. The timing weight is then used as a multiplier in the force law equation governing pin-to-pin attraction. Pins that need to be moved closer together to satisfy timing constraints tend to have weights increased (modulo possible normalization, noted below), in some usage scenarios in a manner varying with the amount of slack available. That is, the less slack (or more negative slack), the greater the positive adjustment to the attraction. Pins that have excess slack tend to have weights decreased. The reduction in weight on pins that have become “over-tightened” creates additional room for relaxation towards an optimal timing state. At least some relative slack embodiments seek to improve timing of nets that do not meet target slack through “bounding box” (or bbox) contraction. Because increases to total net length result in increased capacitance, the associated timing can be negatively impacted by long distance nets—even if the associated load pin is not on the critical path. The long distance net effect may be especially pronounced on large designs. The bounding box contraction considers a range of distances from the net bounding box, to help ensure that the bounding box is continuously contracted (otherwise pins on the bounding box may merely trade places). The incremental approach to change in timing forces provides a quiet and consistent approach to timing closure during the course of an SDI run. In some cases where the timing constraints have been unrealistically set, it may be necessary to introduce a maximum to the total timing forces exerted by the system (for example, adding an upper limit to the ratio of timing net energy to total net energy, through a normalization term). A wide variety of other tunable controls are possible, including but not limited to: baseline relative tightening factor (typically small compared to unity); target min pin slack (typically zero); positive pin slack where relaxation may occur; minimum change in pin slack to consider it in an “improving state”; distance between driver and load pins when no further tightening occurs; distance from net bounding box where tightening starts to occur; min bounding box size when no further “bbox” tightening occurs; and relative strength of bounding box vs. critical path tightening terms. Illustrative Detailed Relative Slack Procedure An illustrative, but not limiting, relative slack procedural flow is as follows. First, in at least some embodiments, a pre-processing phase is performed (in other embodiments this might occur as a post-processing phase), where timing weight adjustment criteria or timing weights themselves are adjusted to control properties of distribution of the timing weights as a whole. The pre-processing permits balancing resulting timing-driven forces with other effects in the system, such as connectivity forces (affecting routability) and expansion fields (affecting routability as well as utilization). Second, update a timing graph using a Timing Kernel (TK). Using the updated timing graph, for every pin on every timing critical net, the slack associated with the respective pin is calculated (See 20,200 of FIG. 20A). Third, iterate over all timing critical nets 20,300, and all load pins on the nets 20,400. Fourth, for each load pin on a respective timing critical net, calculate a respective pin timing weight adjustment (20,500 of FIG. 20A and the entirety of FIG. 20B): 1. Calculate worst slack on the respective net and find bounding box pins. The pins are taken from some region around the bounding box of the net (the size of which is determined by performance tuning, scaling by system size). 2. Determine if the respective driver pin needs to be factored into the bbox calculation. That is, when the driver pin determines the bounding box position, increasing the attraction to nearby pins that are farther from the bbox may be counterproductive. The attraction to pins on the far side of the bbox is likely more influential in decreasing the overall capacitance. FIG. 21A illustrates a driver D in the interior of a net bounding box region determined by loads L1, L2, and L4. FIG. 21B illustrates a driver D to one side of a net bounding box region determined by the driver and loads L1, L2, and L4. 2a. To focus on connections of loads to the driver, the effect of a driver on a bbox is indirectly applied to the loads themselves, through a multiplication factor on any tightening term. 3. For each pin, modify a respective timing weight as needed (see FIG. 20B). 4. For pins that meet target slack (Yes-path from 21,210 to 21,250): 4a. If the slack for the associated is net is negative (No-path from 21,250 to 21,270), then to continue to make positive progress bounding box effects are considered. By taking into account a range of distances from the bbox, rather than a hard boundary, sloshing (oscillations) as pins move onto or off of the bbox is reduced. If (see decision 21,270) a net is near or on the bounding box of a critical net, then determine how much to tighten up the connection. If (see decision 21,280) a load pin is within a specified (small) distance from the driver, do nothing (End 21,285), as further tightening of the connection is counterproductive (e.g. result in increased oscillatory motion between the load and driver). Otherwise, strategies for tightening (increase weight 21,290) include: if the bbox size is sufficiently small, then do nothing; if a pin is on bbox, then tighten at full strength; if a pin is farther than a specified distance from the bbox, then do nothing; and otherwise (in between), then tighten from O-Ix full strength, depending linearly on distance. 4b. If the pin was not tightened (Yes-path from 21,250 to 21,260), then the pin may be considered as a candidate for relaxation (21,260). By allowing connections to either strengthen or weaken, the ability of the system to evolve and relax to an optimal configuration is improved. 4b1. The amount of relaxation allowed for the pin connection is dependent on the worst slack for the net. If the pin has positive slack, but the worst case slack on the net is negative, then the amount of relaxation allowed is reduced. Recall that the pin was not tightened, so little is added to the total capacitance on the net. 4b2. Further, the relaxation is subject to a reasonable upper bound. Otherwise the weights may drop from substantial to nonexistent in a single pass. 4b3. In both of these cases, by moderating the relaxation allowed during one update cycle, we help prevent sudden movement away from what was potentially a fairly optimal solution. This is manifested as increased sloshing in the overall timing performance. 5. For pins having negative slack (No-path from 21,210 to 21,220): 5a. If (see decision 21,220) slack of a constrained pin is improving according to a specified criterion, then let the pin continue to evolve without change (Yes-path to End 21,225). 5b. If (see decision 21,230) the driver and load are within a critical distance, then no tightening is performed (Yes-path to End 21,235). Otherwise tighten the connection (increase weight 21,240), in a manner varying with the ratio of the slack on the pin and the worst negative slack, thus pins most affecting the critical path are likely affected the most. Timing Driven Buffering Embodiments Timing Driven Buffering Overview Timing driven buffering and resizing for integrated circuit designs, e.g. structured array architectures, provides increased performance, reduced cost, or both. Nets having high capacitance and/or fanout and timing critical nets are preferentially processed to reduce maximum delay and/or transition time, enabling allocation of limited structured array resources to more important nets. Timing driven buffering is performed to generate trees of buffers. Timing driven sizing is performed to upsize selected elements. During the buffering Steiner tree routes are segmented and various buffering options are evaluated for each segment according to buffer cost, required time, and lumped capacitance. The options are sorted and partitioned according to the sort. Computational efficiency is improved by eliminating all but a topmost portion of each partition. Options are further evaluated according to performance including timing and routing costs. Displacement coefficients of macros are computed during the sizing to evaluate desirability of reallocating resources implementing less critical macros to more critical macros. A plurality of low-level implementations of each macro are evaluated and compared. Logic replication and tunneling may be performed according to timing improvements and routing costs. Hold time fixes may be implemented by delaying clocks and/or replacing a fast FlipFlop (FF) with a slower element. In some embodiments of design flows relating to array architecture based integrated circuits (e.g. structured arrays or other similar Application Specific Integrated Circuit (ASIC) implementations), timing driven buffering is used to “reconstruct” or “re-synthesize” nets having high capacitive loads or having high fanouts. In some usage scenarios modifying the nets reduces a maximum capacitive load driven by any buffer or driver, or group of elements. In some usage scenarios the modifying reduces a maximum fanout associated with any net or group of nets. In some embodiments a high capacitive load may be driven by a dedicated buffer, or a dedicated tree of buffers. In various embodiments any combination of maximum transition time, maximum rise/fall time, and maximum delay are minimized when performing timing driven buffering. In some embodiments the timing driving buffering is according to fixed resources available in various structured array architectures. In some embodiments the timing driven buffering is iterative (e.g. to achieve timing closure). In some embodiments the timing driven buffering accounts for any combination of local and global congestion. In some embodiments the timing driven buffering includes morphing non-buffer resources and allocating the morphed resources as buffers. In some embodiments of array architecture design flows, timing driven gate resizing is used to improve performance of various combinations of highly capacitive and high fanout nets. Logic gates are upsized (i.e. replaced with a gate having an equivalent logic function but greater drive strength) as necessary to reduce maximum delay and/or transition times. In some embodiments the upsizing is via so-called “form replacement” or replacing a form level macro with an alternate form level macro (such as substituting a gate with a higher drive strength for a gate with a lower drive strength). In some embodiments timing driven gate resizing is constrained according to fixed resources available in various structured array architectures. In some embodiments a plurality of resources are simultaneously “swapped” (i.e. deallocated from a first use and reallocated to a second use) to improve critical path timing. In some embodiments the timing driven gate resizing includes morphing non-buffer resources and allocating the morphed resources as “upsized” gates or buffers. In various embodiments of timing driven buffering and resizing for structured array architectures, timing driven hold time fixes are implemented by any combination of morphing, delaying clock signals, and buffering. In some embodiments any combination of logic replication and tunneling are used to improve circuit performance of designs implemented according to a structure array fabric. FIGS. 22A and 22B illustrate, respectively, an example circuit excerpt before and after processing according to an embodiment of timing driven buffering and resizing for an array architecture. FIG. 22A illustrates critical load C2 driven by buffer b2 that is driven by buffer b1 that is in turn coupled to Driver. Thus there are two buffers between the driver and the critical load. Non-critical loads NC1 and NC2 are also driven by buffer b2. Loads on a critical path from Driver to C2 include c0 driven by Driver and C1 driven by buffer b1. FIG. 22B illustrates a result of timing driven buffering and resizing, as applied to the topology of FIG. 22A, where critical load C2 is driven from new/modified buffer b1′ that is directly coupled to Driver. Thus there is only one buffer between the driver and the critical load, providing enhanced arrival time for the critical load compared to the topology of FIG. 22A. Structured ASIC Timing Closure FIG. 23 illustrates a flow diagram of an integrated circuit design flow including an embodiment of processing in accordance with an embodiment of timing driven buffering and resizing for an array architecture, e.g. a structured ASIC. Timing Driven Buffering FIG. 24A illustrates a top-level view of an embodiment of timing driven buffering and resizing for an array architecture. In some usage scenarios timing driven buffering and resizing serves to reduce delays of critical path elements and decrease transition times associated with drivers (or nets or both). Routing-aware buffering is used to reduce maximum congestion in otherwise heavily congested regions. In some embodiments an initial buffering phase is performed ignoring timing-driven constraints, while in other embodiments the initial buffering accounts for timing-driven constraints. According to various implementations timing-driven buffering and resizing includes any combination of net prioritization, global Steiner tree routing, evaluating multiple route trees, computing buffering options, pruning, and determining and selecting a solution. In some embodiments a buffering subsystem processes nets individually, prioritizing the nets according to timing criticality, enabling preferential treatment for more critical nets. The preferential treatment is according to any combination of buffering resources, wiring resources, and routing congestion (measured according to a metric). In structured array usage scenarios, buffer resources are finite and several nets may be simultaneously competing for the same resources. Ordering nets and processing the most critical nets (or the nets having the highest negative slack) first provides the more critical nets with access to the buffer resources first. In addition, as more nets are processed, the most critical of the remaining nets have access to wire routing regions most beneficial to routing the remaining nets through. Less critical nets are relegated to more meandering routes to meet region congestion constraints. In some embodiments the buffering subsystem initially constructs global Steiner tree routes for all nets to estimate heavily congested regions. Routing and/or congestion hotspots that should be avoided while buffering (at least for non-critical nets) are identified. In some embodiments the buffering subsystem initially builds multiple route trees for each driver that couple the respective driver to all loads of the driver. The route trees are heuristic based, and the heuristics include prioritizing critical loads differently than non-critical loads and operating with an awareness of the previously identified hotspots. The route tree building includes any combination of shortest path weight and net spanning factor techniques, enabling results having different topologies. In one embodiment of one of the route tree heuristics, loads are first grouped into multiple partitions based on load (or pin) criticality. More critical loads are prioritized for Steiner tree route construction first. Then less critical loads are processed, enabling the more critical loads to have a more direct route from driver to load. In addition, the more critical loads are presented with higher shortest path weight, thus reducing branching of the route tree from the more critical loads to the less critical loads. In some implementations a Steiner tree based route is decomposed into several segments, such as according to a global cell granularity used when constructing the Steiner tree based route. A dynamic programming technique is used to compute a buffer solution for each of the route trees. The dynamic technique includes maintaining several solutions for each segment to be considered for use to implement a sub-tree of the respective route tree. The respective route tree is processed bottom-up, i.e. all of the load terminals of the tree are visited before the driver. Buffering options at a segment are computed by combining solutions of all predecessor sub-trees with a current solution. FIG. 25A illustrates a portion of a route tree having several branches decomposed into segments according to processing by an embodiment of timing driven buffering. Child options are a function of downstream options. For example: Options at S0=Product(Options at S1, Options at S2). FIG. 25B illustrates several segment options for segment S0 of FIG. 25A. The options include no buffering (Opt1), a buffer before the branch to segment S2 (Opt2), a buffer on segment S1 (after the branch as Opt3), a buffer on segment S2 (after the branch as Opt4), and two buffers after the branch, one on each of segments S1 and S2 (Opt5). If a segment currently being processed is a branch point, then the current segment has multiple sub-trees below it, and each of the sub-trees contains an array of options. The options are merged by performing a cross product of option sets. After computing the cross product, each feasible solution for the sub-tree is combined with a buffering solution for the current segment. Multiple segment options are computed for each segment. The number of options produced is proportional to the number of buffer types (or buffer electrical characteristics) available according to technology associated with an integrated circuit design (such as a standard cell library). In some implementations various options are computed for each segment, including a non-buffered option, a high-drive strength buffer option, and a low-drive strength buffer option. For each option, several parameters are determined, including Buffer Cost (BC), Required Time (RT), and lumped Capacitive Load (CL). The parameters are subsequently used to determine option cost and feasibility. BC measures cost according to the buffering solution for the entire sub-tree “underneath” the segment being evaluated. RT measures expected required time for a signal at the input of the segment. CL measures cumulative capacitive load of the segment and all associated child segments. Pruning techniques are used to limit computation, maintaining selected options for each route segment. The selected options chosen are those most likely to result in a “good” solution according to the root of the route tree. A first pruning technique includes deleting any infeasible solutions, such as a buffering option that has accumulated capacitance exceeding the maximum drive capability according to available buffers. A second pruning technique removes redundant options. An option having higher BC, smaller RT, and higher BC compared to an existing option is considered redundant. A third pruning technique includes trimming the number of options according to an upper bound. In some embodiments the upper bound is variable, while in other embodiments the upper bound is predetermined (at a value such as 10, 20, 50, or 100). In some implementations the options are sorted in order of RT (highest RT first). In some embodiments a contiguous portion of the top of the sorted options is retained, the portion being equal in number to the upper bound (i.e. the “best” options are kept). In some embodiments the sorted options are partitioned into four quarters, and a number of options are preserved from each quarter. In some embodiments the number is chosen to be one-fourth of the upper bound. In some usage scenarios the preserving according to partitions enables discovery of solutions that appear locally inferior, but when combined with parent segments appear superior. In some embodiments determining and selecting a buffering solution includes evaluating options according to performance (such as arrival time) and (estimated) routing congestion. A disproportionately higher weighting is applied to timing cost when evaluating a critical net. A buffering solution having lower hotspot (i.e. congestion) cost is preferentially chosen for non-critical nets. Timing Driven Sizing FIG. 24B illustrates a detail view of selected details of an embodiment of timing driven resizing for an array architecture. Timing-driven form sizing (or resizing) selects alternate forms to improve any combination of drive capability and stage delay, for example by replacing a lower drive strength gate with a relatively higher drive strength gate. In some usage scenarios macro or form sizing is preferred over buffering when cost of upsizing a driver is less than buffering a net. In some structured ASIC usage scenarios buffer sites are predetermined according to block tiles, and thus the fixed locations of buffer sites may result in relatively high intrinsic buffer cost or associated congestion cost. In some situations there may be no available sites (or slots) near a macro targeted for resizing. In some embodiments a form-sizing subsystem attempts to discover nearby sites by (re)implementing the macro using a different set of primitives. According to various embodiments the primitives correspond to standard cells, structured array tile elements, or other similar low-level resources. In some implementations the form-sizing subsystem is enabled to “displace” (or “move”) selected forms (such as forms on non-critical paths) that are initially near the macro that is to be resized. In structured array integrated circuit designs, strictly speaking the forms are not moved, but instead fixed-location sites are deallocated in one area and reallocated in another area. A Displacement Coefficient (DC) of a macro is computed as follows: DC of macro=Sum (DC of each morphable form within the macro); and DC of a morphable form=Product(primitive densities of all the primitives within the morphable form). The DC is a conceptual measurement of “placeability” or ease of placement of an element when the element is currently unplaced. A macro is more placeable if it may be implemented with more morphable alternatives. A morphable alternative is more placeable if the primitives of the morphable alternative are placeable (or relatively more placeable), such as when there are available (or unused) sites for the primitives. The primitive densities relating to the DCs of morphable forms are computed as follows. A site density grid is constructed that is a two-dimensional matrix of grid resource usage. For each element of the density grid, a number of available resources and used resources are computed for each resource type. Relatively sharp density gradients are smoothed by accumulating density from eight neighboring grid elements to a respective grid element. Thus the computed density at each grid element is an average density at the element in conjunction with eight nearest neighboring elements. The site density grid values are then used to determine the DCs of the morphable forms. The DC of a morphable form is computed by looking up the density of each of the primitives of the morphable form, within the site density grid and according to respective primitive types. The morphable form DC computation continues by multiplying the look up results (i.e. primitive densities) together. If a particular resource or resource type is depleted (or nearly depleted) within the grid, then the morphable form DC is zero (or nearly zero). Thus the resource depletion results in the placeability of the morphable form being low. Resizing a macro includes selecting a form from a plurality of implementation choices. Each of the choices is speculatively selected and evaluated with respect to the macro being resized. A timing score is computed that is equal to arrival time at an output of the macro assuming the macro is implemented with the speculatively selected form. If the timing score is poorer than previously saved possible implementation choices, then the current choice is rejected. If the timing score is better, and the drive strength of the speculatively selected form is sufficient to drive the capacitive load at the output, then the speculatively selected form is saved as a possible implementation choice. In some embodiments placing a macro after determining an implementation according to one or more morphable forms proceeds as follows. New coordinates of the (now form level) macro are computed based on all of the connections of the form level macro. The coordinates of drivers of nets connected to all of the input pins of the form level macro as well as associated net fanouts are used to compute the new coordinates. In some embodiments a form placing sub-system performs an attempted placement of each of the possible implementation choices determined during the resizing of the macro. The underlying morphable forms are already prioritized based on the respective timing scores, and the attempted placements are performed in priority order (i.e. morphable forms resulting in better arrival times are tried first). Each primitive of each respective morphable form is placed individually as follows. A site locator (or slot locator) searches all possible sites around a given coordinate within a certain window size. If a respective site is unoccupied, then the unoccupied site is assigned to the primitive. If the respective site is occupied, then the DC of the parent form level macro of the occupied site is looked up. If the DC is below a threshold value, then the parent macro is left untouched and other sites are tried. If the DC is above the threshold, then the parent macro is scheduled to move from the site (i.e. the primitive in the site will be placed elsewhere) and the primitive is assigned to the site. The parent macro that is scheduled to move is queued to be visited later based on criticality of the parent macro. Timing Driven Logic Replication and Tunneling In some embodiments a driver node is logically replicated for nets having high capacitive loading or high fanout. The replication is performed selectively according to evaluations of timing improvements and routing costs. In some embodiments tunneling is performed to move the driver closer to a cluster of loads. In some embodiments the tunneling is performed after evaluating the timing improvements and routing costs. FIG. 26 illustrates example results of an embodiment of logic replication and tunneling for an array architecture. The example illustrates a single FF driving three clusters of load (C1, C2 and C3). After replication and tunneling (shown in the lower portion of the figure), the FF is replicated as FF1, FF2, and FF3. Each of the replicated FFs is then placed near the respective cluster driven by the FF. Timing Driven Hold Time Fixes In some embodiments timing driven hold time fixes proceed as follows. Excess setup time (or slack setup time) is determined for each launch FF that is a root of a hold time violation. If there is excess setup time, then in some embodiments the clock signal feeding the launch FF is delayed. In some implementations the delay is via addition of a dummy load. In other embodiments a hold time violation is addressed by morphing the launch FF to a slower FF. In some implementations the morphing is via swapping the (original) launch FF with an unused (or available) slower FF. Density Enhancement Embodiments Node density in various SDI embodiments is influenced by a variety of effects, including netlist connectivity, circuit performance, and expansion fields. The former two exert an attractive force between nodes that depends upon netlist topology considerations or critical path analysis. For brevity these are referred to as “connectivity forces”. Without the presence of expansion fields, the connectivity forces tend to draw together nodes into a highly clumped configuration that may exceed local slot resource supply. Spreading of nodes by the expansion fields then serves a twofold purpose: (a) provide solutions to slot assignment over some suitably chosen sub-discretization of a die, and (b) enhance routability, since localized clumping of nodes implies greater local demand for routing resources. In a chip floorplan that is free of obstructions, very strong expansion fields result in a node distribution that is almost perfectly uniform. However this situation may not be desirable, since some amount of clumping may be beneficial. Once the node distribution reaches the point of routability, further increases to the expansion field strength may only worsen the routing problem by forcing nodes further apart than is optimal, seen by examining cutscores or circuit performance as a function of expansion field strength. Further, the demand for routing resources may exceed supply only in very localized regions, while the bulk of the node distribution presents a tractable routing problem. The localized regions may occur due to netlist (topological) or floorplan effects. Increasing the expansion field strength to compensate for the “lumpiness” of the node distribution in selected regions affects the distribution as a whole, and in some usage scenarios may be suboptimal. In cases where the floorplan contains obstructions, the supply of routing resources can be a complex function of position on the die, and here a global approach can fail to have the desired effect entirely. The illustrative but not limiting density-driven approaches presented here for addressing the problem of routing congestion in SDI can be categorized as follows: 1. Region Based a. By factor b. By function 2. Steiner Cuts Based a. Relative b. Absolute (i.e. supply vs demand) In the illustrative density enhancement embodiments, the density enhancement is inserted between the “fold” and “filtering” phases of node density computation. The flow 27,100 for density modification is illustrated in FIG. 27. Note effects introduced by procedures 27,100b, 27,100c, and 27,100d are completely independent of each other and can therefore be applied in any combination. In procedure 27,100a, the normalization factor is typically taken as the average density, not counting that in excluded regions. In procedure 27,100b, for each defined region that possesses a density scaling factor, the density is multiplied by the associated factor at each density field gridpoint contained within the region. Note this technique is essentially the same as increasing the effective mass for each node contained therein. Given a statistically uniform node distribution to start with, the scale factor density enhancement tends to drive nodes out of the specified region, ultimately resulting in a node density on the order of (average density)/(scale factor) there, edge effects notwithstanding. Any number of such regions and scale factors can be defined. Regions may overlap if so desired. In procedure 27,100c, for each defined region that possesses a density enhancement function, the associated spatial variation multiplied by the normalization factor is added to the existing density. The spatial variation is evaluated at each density field gridpoint contained within the region. In some embodiments an arbitrary functional variation is supported by expressing the function in Tcl (Tool Command Language) and using an embedded Tcl interpreter to return the result of the given expression at each gridpoint. The functional variation enhancement may be well suited for the case where the node density becomes very rarefied, e.g. in small channels between obstructions. In rareified density situations, the scale factor approach becomes less effective for pushing nodes out of the region, since there are fewer nodes to “push against”. The functional variation serves essentially as a background density, only depending on the existing node density through the normalization factor (which is global). As in procedure 27,100b, there is no limit to the number of regions and functions that can be defined, and regions may overlap if desired. In procedure 27,100d, a Steiner-cuts congestion density enhancement term is added. At this point in the flow, for this density enhancement embodiment, a congestion enhancement value at each gridpoint is available (described in detail below). Adding the congestion enhancement term (times a suitable normalization factor, e.g. the average density) for each gridpoint gives a final result. The flow 28,200 used to determine the Steiner-cuts congestion term on the SDI grid in the density enhancement embodiment is given in FIG. 28. In procedure 28,200a, a so-called “congestion array” is generated that is a measure of routing congestion output, taken from a Steiner cuts measurement. Since the calculation of routing congestion may be computationally expensive, the congestion array need only be calculated initially and at specified intervals as a run proceeds. An intermediate grid is used to assert the independence of the congestion array from the particular form of the routing congestion diagnostic, as well as from the SDI grid resolution. The procedures used to create the congestion array are illustrated in FIG. 29. In procedure 28,200b, the congestion array is run-length averaged according to a specified relaxation factor. This helps prevent sudden “shock” to the system (which can cause unphysical fluctuations) every time the congestion array is recalculated, by phasing the change in gradually. The relaxation parameter is chosen to vary from zero (static; congestion array never changes) to unity (congestion array changes instantaneously). In procedure 28,200c, a final congestion density enhancement array is calculated. The calculation may be performed once each timestep, in response to configuration changes, or both. Further details are illustrated in FIG. 30. In procedure 29,300a, the Steiner-cuts array is fetched from the generator. In some embodiments a timing kernel (TK) performs procedure 29,300a. The calculation may include an idealized buffer tree, at implementor or user discretion. In procedure 29,300b, the Steiner-cuts array is subject to a filtering operation to increase smoothness, which helps improve accuracy of a subsequent interpolation procedure. In some embodiments a number of binomial digital filter passes are used. In procedure 29,00c, the value at each gridpoint in the intermediate grid discretization is calculated using a linear spline approach. In procedure 30,400a, the congestion array is smoothed using filtering similar procedure 29,300b, in part to improve the accuracy of the interpolation. But filtering is also considered the “final smoothing” phase of the field and is subject to the most user and/or programmatic control, to improve the quality of the final result. The smoothing is most effective when the scale lengths associated with the variation of the density enhancement are “semi-global”, e.g. small compared to the die size, but large compared to motion of a node in a single timestep. In procedure 30,400b, the congestion array is normalized as needed. First it is clipped at a pre-determined value of maximum congestion, to constrain resulting density gradients within reasonable limits. In relative spreading mode, a normalization of unity is imposed, thus inducing a density-driven outflow from congested areas without regard to actual routing supply. In absolute spreading mode, the routing demand versus supply is compared to the maximum allowable relative demand (e.g. 80% capacity). Only at gridpoints where congestion exceeds the allowed limit does the enhancement field take on substantial values (while enforcing a reasonably smooth variation). In the case of a density-gradient model for calculating the expansion fields, the congestion density field that results is flat everywhere that routing supply satisfies demand, rising smoothly into elevated “mounds” at locations where the demand exceeds supply. The congestion array is then modified according to desired strength of the density enhancement effect. Both multiplicative and power-law transformations may be applied. The strength of the enhancement may be increased over time to allow for the gradual movement of nodes out of congested areas. In procedure 30,400c, the value of the congestion array at each SDI gridpoint is calculated using a linear spline approach. Tunneling Congestion Relief Embodiments In some SDI-based integrated circuit design flow embodiments “tunneling” is used to relieve congestion at boundaries. Tunneling governs transitions of nodes through one or more obstructed regions not available for node placement, i.e. xzones, of a chip (or portion thereof). In some embodiments the transition is according to a mathematical criterion. In some embodiments nodes are selected as tunneling candidates according to node attraction into one of the obstructed regions. In some embodiments the criterion is affected by node density. In some embodiments the criterion is affected by node interconnections (or connectivity). In some embodiments the criterion is affected by circuit performance (i.e. timing). Tunneling enables further placement progress, according to selected metrics such as routability and circuit performance, while taking into account xzones. Tunneling has several aspects including candidate node selection, nodal move speculation, and node tunneling criteria (i.e. keep move/tunnel or reject). In some embodiments tunneling is performed at the end of an SDI timestep. Any intervening sub-steps taken by the time integrator (e.g. part steps taken by a Runge-Kutta (RK) integrator) are not considered. During the course of a timestep (and any associated sub-steps) the nodes are allowed to drift into xzones in order to allow the time integrator to proceed at full speed, since in some usage scenarios a smooth trajectory in a numerical simulation enables more accurate integration, and thus may enable a longer timestep (given a predetermined accuracy target). At the end of one full timestep, only nodes that have been coerced into xzones are considered for tunneling speculation. FIG. 31 illustrates an embodiment of a processing flow for node tunneling out of exclusion zones in an SDI-based integrated circuit design flow. In some implementations any combination of the illustrated elements are performed by software routines known collectively as a “node mover”. In 31,100a nodes are selected as candidates for tunneling based on respective positions. Nodes that have moved into an xzone are included in a set of all transiting nodes. Each respective node will have arrived at the respective position (or point) due to (discounting inertial effects) the vector sum of all forces acting on the respective node. For example, some of the forces may be due to netlist connectivity (i.e. the respective node is drawn towards topologically close nodes) and some of the forces may be due to a local overabundance of nodes (density buildup). In some usage scenarios selecting nodes in xzones for tunneling consideration is an efficient selection criteria that discriminates nodes likely to benefit from a tunneling transition to another side of an xzone or multiple abutting xzones. In 31,100b, having determined candidate nodes, per-node initialization is performed. In some usage scenarios total tunneling candidate nodes are a small fraction of total nodes, and for efficiency a secondary set of data structures is used to process the candidate nodes. A transiting node class contains a node id (that maps to an original node entry) and any ancillary data required for accurate tunneling speculation. Henceforth, the class of all node candidates for tunneling is referred to as “transiting nodes”. In 31,100c, all transiting nodes are snapped to the nearest xzone boundary. The snapped position is identical to the resulting node position were no tunneling to occur, and assures a baseline for proper field computation and comparison to the post-transit result. In 31,100d, the forces on transiting nodes at the current positions (pre-speculation) are evaluated. See the discussion relating to FIG. 32 located elsewhere herein for further information. In 31,100e, the position of the transiting node is restored to the positions before processing relating to 31,100c. The node mover then finds the intercept on the xzone boundary that results from application of the force vector components on the node. In some embodiments node inertia is also taken into account when determining the xzone boundary intercept. The node is speculatively moved to just past the intercept position, outside the original xzone. In the event that multiple abutting xzones exist and the node lands in yet another xzone, the mover is invoked again using the original trajectory to direct the move. The speculative movement procedure is continued as many times as necessary for the node to arrive in a region external to any xzone. In 31,100f, the forces on transiting nodes at the new positions (post-speculation) are evaluated. See the discussion relating to FIG. 32 located elsewhere herein for further information. In 31,100g, the transition criteria are evaluated and examined. If the transition is accepted, then the node associated with the transiting node acquires the new coordinates. Otherwise the coordinates as determined in 31,100c are retained. See the discussion relating to FIG. 33 located elsewhere herein for further information. FIG. 32 illustrates an embodiment of SDI-related force calculations in a tunneling congestion relief context. In 32,200a, forces on the node are cleared and preparations are made for the field calculation. In 32,200b, forces on each node due to all non-field interactions are summed, including all connectivity and timing based pin to pin forces, as well as any other nodal interaction forces present. In 32,200c, gate field components are computed. The first time through (pre-speculation phase), a full field calculation is performed. The pre-speculation phase is with the nodes snapped to the nearest xzone boundary, so the result represents a result assuming no nodes transit. The second time through (post-speculation phase), the field calculation from the first phase is used, but applied to the speculative nodal coordinates. That is, it is assumed that the fields are not significantly changed on a global scale as a result of tunneling. In some usage scenarios, since only a small number of transitions are considered relative to the total number of nodes, the assumption serves as a reasonable approximation, and may be beneficial for computational efficiency since field computations for each individual speculation are avoided. FIG. 33 illustrates an embodiment of evaluation of tunneling transition criteria. In 33,300a, the speculative node coordinates are examined to see if there are violations of any node region constraints and if nodes fall into a legal logic area. If there is any violation, then the transition is rejected. In 33,300b, a statistical window on how many transitions are considered is applied. In some implementations the window is small (such as 1%, 2%, 5%, or 10%) compared to unity but not so small that an inordinate number of passes through speculator routines are required to process all qualifying nodes. The windowing helps prevent sloshing, where many nodes tunnel from a high to a low density region at once, altering density so much that nodes tunnel back later. In other words, the statistical window helps to ensure that approximations made with respect to 32,200c (of FIG. 32) are valid. In 33,300c, a variety of biasing factors are applied. In some implementations the factors are multiplied together. In some implementations one or more of the factors is less than unity. The factors include any combination of the following. A default biasing factor. A bias against multiple transitions in a row, to ensure longer relaxation time. A distance based biasing, to make it more difficult to travel long distances. The distance based biasing may involve either a hard limit or a functional dependence on distance traveled (e.g. linear or quadratic). A distance based biasing specific to timing critical nodes. Nodes on a critical path may have an unpredictable effect on timing due to tunneling, so the critical path nodes may be selectively more further constrained than other nodes. In 33,300d, the magnitude of the forces on the node at the old and the new positions are computed. If the new force magnitude after biasing is less than the old force magnitude, then the transition is considered to be energetically favorable and therefore accepted. Otherwise the transition is rejected. Clock Tree Synthesis (CTS) Embodiments CTS is a process for creating a clock network in an Integrated Circuit (IC) physical design flow. CTS has general applicability to design flows having limited placement options for clock buffers, such as SAF-based design flows. Note that although CTS is described herein within a general context of an SDI-based flow, there are applications to other types of design flows using conventional EDA tools. In some usage scenarios a structured ASIC design has one or more clock signals that fan out to many (perhaps thousands) of register clock pins. A register clock pin may be a clock pin of a flip-flop, a latch, or clock pins of embedded memory and other IP blocks. Clock nets produced by logic synthesis or derived from schematics act as placeholders for CTS-produced clock nets. Each of the logic synthesized clock nets drives a high drive strength buffer (an ideal clock). Each of the CTS-produced clock nets includes one or more levels of buffers, interconnect wires, and other gating logic such as clock_and, clock_or, clock_mux, and other similar clock manipulation elements. In some embodiments CTS is run post placement so that precise coordinates of clock pins driven by each clock net are known (such as portions of processing performed in conjunction with “Buffering Clock Tree Synthesis Timing Driven Buffering/Resizing” 821 of FIG. 8A). In some implementations a CTS tool builds a clock network that strives to optimize characteristics of the clock network including skew and latency. Clock skew is the difference of signal arrival times at clock pins of two registers. The CTS tool optimizes a maximum clock skew of the circuit, i.e. the largest clock skew between any pair of registers that have timing paths (setup/hold) between them is minimized. Clock latency is delay from a root of a clock tree to a clock input pin of a register. The CTS tool optimizes the maximum latency, i.e. the largest delay is minimized. In addition to skew and latency metrics, there are other considerations such as power and routing congestion addressed by the CTS tool. The CTS tool attempts to optimize (i.e. minimize) the buffers and wire resources used for clock distribution since the resources directly impact circuit routing congestion and dynamic power usage. In some embodiments CTS is performed in a post detail placement phase to enable building optimized clock networks, based on locations of clock leaf pins. Gating logic enables power reduction by selectively turning on and off sub-trees of a clock tree. Clock selector logic (such as using a clock_mux) multiplexes multiple user clocks and test clocks. A clock tree may have several levels of clock selector logic gates and several levels of clock gating logic gates. In some usage scenarios clock gating circuitry is pre-designed by the user at a hardware description level and is then synthesized into gates by a synthesis tool. The CTS tool balances clock networks while taking into consideration delays of various gating logic, thus treating the gating logic transparently and automatically. FIG. 34A illustrates an example clock tree suitable for input to a CTS tool for SAF-based design flows. Primary clock domains are illustrated as pclk0 and pclk1. Gated clock sub-domains are illustrated as gclk0 and gclk1. A clock selector based clock sub-domain is illustrated as mclk. Clocks pins of registers are illustrated as ckp0, ckp1, . . . ckpn; ckg0, . . . ckgn; cks0, cks1, . . . cksn; and cksg0, . . . cksgn. Register clock pins ckg0, . . . ckgn and cksg0, cksgn are associated with gated clocks. Register pins cks0, cks1, . . . cksn are associated with selected clocks. Register clock pins cksg0, . . . cksgn are associated with two levels of clock processing (select and gate functions). FIG. 34B illustrates an example clock tree output from the CTS tool operating on the input illustrated in FIG. 34A. In the illustrated output various Clock Networks produced by the CTS tool (according to the input illustrated by FIG. 34A) are shown driving the register clock pins. FIG. 34C illustrates an example clock tree network. Leaf buffers are illustrated as b1, b2, b3, and b4. Each of the buffers are shown driving (or fanning out to) a respective sea of clock pins as illustrated conceptually by the triangular element at each respective driver output. Terminals of the clock network are illustrated as t1, t2, and t3. Selected terminal buffers are illustrated as tb1 and tb2. A clock root is illustrated as CT. The illustrated clock tree network is representative of some implementations of the Clock Networks of FIG. 34B. For example, consider the Clock Network of FIG. 34B driving register clock pins ckp0, ckp1, . . . ckpn. CT of FIG. 34C corresponds to the element driving pclk0. Leaf buffer b1 drives ckp0, leaf buffer b2 drives ckp1, and so forth. FIG. 35 illustrates an overview of an embodiment of a CTS flow. According to various embodiments the CTS flow includes any combination of floorplan driven clock partitioning, topological clock sorting, top-down recursive bi-partitioning, clock domain (and sub-domain) processing, bottom-up skew minimization, and top-down buffer placement. Floorplan driven clock partitioning (such as illustrated in FIG. 35) may be used when a die floorplan has extensive arrays of RAM and/or IP structures that lack suitable sites or slots for clock tree buffer elements. When the CTS tool builds a clock tree, buffer sites at intermediate points of each clock network are used to drive two sub-trees “underneath” the respective intermediate point. Having large rows(columns) of RAMs/IP blocks implies that there are extensive die regions that are either completely devoid of clock buffer sites or have the sites at sub-optimal locations. Therefore, CTS preprocesses the clock network and embeds Pseudo-clock Sub-Domains (PSDs) that are first balanced within each row(column). Subsequently, the clock sub-domains are deskewed across logic rows(columns). The first level PSDs can be deskewed by buffer resources within a row(column), thus alleviating the need to find sites over RAM and/or IP regions. FIG. 36A illustrates an example die floorplan of a design having embedded RAM or other IP blocks. Regions 36,300a represent an I/O ring. Regions 36,300b1, 36,300b2, and 36,300b3 represent rows of embedded RAMs. Regions 36,300c1, 36,300c2, and 36,300c3 represent rows of logic blocks. CTS clock preprocessing proceeds as follows. Within each PSD, all clock leaf pins in each contiguous logic region (such as each of regions 36,300c1, 36,300c2, and 36,300c3) are merged so the leaf pins fan out from a single Root Clock row(column) Buffer (RCB). The RCB is optimally placed at the centroid of the bounding-box encompassed by all the leaf clock pins within the respective logic region. All RAM clock pins are then combined with logic clock pins by drawing a partitioning line through the middle of each RAM region. For example, if there are RAM clock pins in region 36,300b2, then each one is merged with clock pins of one of adjacent regions 36,300c1 or 36,300c2 depending on proximity of the respective RAM clock pin to the adjacent regions (i.e. the closest one of the regions is chosen). Then each of the region PSDs are deskewed individually. In some usage scenarios the deskewing is by combining even and odd row(column) RCBs separately. In other words, every other row(column) is processed together. In situations where RAM (or IP) rows(columns) are alternated with logic block rows(columns), and the rows(columns) are of approximately the same size, processing even/odd rows(columns) separately simplifies equidistant placement of RCB pairs, since the center of each RCB pair will be in a logic block row(column). For example, RCBs associated with region 36,300c1 are processed with RCBs associated with region 36,300c3, and equidistant placement may be satisfied by region 36,300c2, a logic region. Note that the RCBs associated with a logic region may include RAM clock pins from adjacent RAM regions, such as region 36,300c1 RCBs include merge RAM clock pins from the upper half of region 36,300b2 and the lower half of region 36,300b1. Subsequently, the even and odd RCBs are deskewed at the clock root. The aforementioned merging, partitioning, and RCB placement processing is performed for each primary clock. The leaf clock pins driven by gated-clocks and clock selectors cells are treated transparently during the processing. If a gated-clock or clock-selector logic drives leaf clock pins in multiple logic regions, then the gating logic is replicated in each of the respective regions the gated clock fans out to, thus enabling transparent merging of un-gated and gated-clock leaf pins. FIG. 36B illustrates a portion of a clock net in a context of a portion of FIG. 36A. Clock net “clk” feeds both un-gated and gated clock pins that span out to logic regions 36,300c1 and 36,300c2. The gated clock is replicated in region 36,300c2 so that the RCB in each region is enabled to independently drive both the un-gated and the gated branches of the clock trees. The replication technique reduces multi-level clock balancing across RAM regions and introduction of skew uncertainties. Topological clock sorting, or domain ordering (such as illustrated in FIG. 35) is performed so that the CTS tool visits the clock domains in an order that facilitates deskewing of lower level sub-domains prior to higher level sub-domains. In some embodiments various clock sorting functions are performed by software routines implemented in a topological sorter. In some usage scenarios a primary clock has several gated-clock and select-clock logic based sub-domains. As shown in FIG. 34A, main clock (clk) fans out to several leaf level clock pins after several levels of gating (gclk0, mclk, and gclk1). The sub-domains gclk0, mclk, and gclk1 carry the same primary clock (clk), but are gated (controlled) by user logic to enable selectively turning off for one or more clock cycles. Clock distribution information of FIG. 34A is processed by the topological sorter to produce sub-domain ordering: gclk1->mclk->gclk0->pclk0->pclk1->clk. The ordering ensures that when the un-gated leaf level pins of clk nets are being deskewed with the gated-clock pin (gclk0), the gated clock pin has already been completely processed (expanded) and any associated clock network latency is determined. Clock domains(and sub-domain) processing (such as illustrated in FIG. 35) includes processing the domains according to the topological domain ordering. A Clock Domain Processor (CDP) of the CTS tool first collects all clock pins to be deskewed. A user may mark pins to be excluded for deskewing and the CDP obeys the marking. The CDP forms two level clusters. For all the leaf clock pins that are pins of a leaf level register (such as flipflops, latches, and RAM blocks), recursive partitioning forms bottom-up clusters that may be driven by a leaf level clock buffer. Clustering of leaf level clock pins (such as illustrated in FIG. 35) is performed via recursive partitioning of all the leaf level clock pins, and forms small well-formed clock pin clusters that may be driven by leaf level clock buffers, thus reducing complexity of leaf level clock buffer implementation. The partitioning uses recursive bipartitioning with an objective function that minimizes the diameter of the polygon formed by all pins in a partition. As the diameter of the polygon computation has polynomial complexity, in some implementations a fast heuristic technique with linear complexity is used. The linear complexity technique computes an NSP of a bounding box of all leaf level pins in a partition. Clusters are also formed to increase relative “closeness” to other clusters having common setup and hold paths. Cluster closeness of two clusters is the number of clock buffers common to the clusters. In other words, tightly coupled leaf clock pins are grouped to share relatively many clock buffers, thus enabling more efficient skew reduction. FIG. 37A illustrates an example of timing driven pin swapping. As illustrated, it is preferable to partition clusters as P1={La, Ca}, P2={Lb, Cb} instead of P1={La, Lb} and P2={Ca, Cb}. The former promotes sharing of clock buffers between launch and capture flip-flops thereby reducing the skew between launch and capture flip-flops since unshared clock buffers may be subject to separate process, voltage, and temperature variations and thus may introduce skew. During recursive bipartitioning, each partition is scored based on timing relationships between each pin and every other pin of the partition. Cluster cost is a weighted sum of interconnect wiring cost and cluster-closeness cost. The interconnect wiring cost is determined from the NSP of the bounding box of all the pins constituting the cluster. For example, partition cost may be given by: Part_cost=0.5*cic*cic+0.5*ctc*ctc where cic: is cluster interconnect cost, given by: cic=(1−part_interconnect_cost/best_interconnect_cost); and ctc is cluster timing cost given by ctc=(1−part_timing_cost/best_timing_cost). Additionally, pairwise swapping of edge pins based on timing relationships of the pins within the cluster is performed. The swapping is directed to achieve maximal common launch and capture paths for a pair of clock pins that have either a setup path or a hold path in common. FIG. 37B illustrates an example of effects of (top-down) clock tree partitioning. A random distribution of clock pins is illustrated in the upper portion of the figure. Results of clock tree partitioning and cluster formation are illustrated in the lower portion of the figure. The CDP performs top-down partitioning using leaf-level buffer input pins and any clock sub-domain clock pins. Clock sub-domain clock input pins include input pins of gated clock cells, clock selector cells, and derived clock pins of flip-flops. The clock sub-domains are processed top-down instead of being clustered with leaf level clock pins, thus enabling insertion delay of the clock sub-domain to be utilized to balance the sub-domains. As illustrated, results of a first recursive partitioning pass are shown as 37,100. Results of a pair of (independent) second recursive partitioning passes are shown as 37,200a and 37,200b. Results of a third recursive partitioning pass are shown as 37,300b. Note that although the recursive portioning results are illustrated as straight cut-lines splitting contiguous regions, various embodiments and starting conditions may result in cut-lines of any shape or form, such as zig-zags, curves, and so forth. Further note that the split regions may be non-contiguous; i.e. form one or more “islands” driven by a single leaf-level buffer. FIG. 38 illustrates an analysis according to an embodiment of clock domain and sub-domain partitioning. A clock “Root” is illustrated with relationships to leaf buffers lb1, lb2, lb3, lb4, lb5, lb6, and lb7. A tree of clock terminals is illustrated by t1, t2, t3, t4, t5, t6, and t7. In some embodiments edges are added to represent timing relationships (such as setup and hold times) between leaf level buffers. One type of timing relationship between first and second buffers is when the first buffer drives a first storage element, the second buffer drives a second storage element, and the two storage elements are coupled via a path having a setup (or hold) timing constraint. An example setup(hold) timing relationship between a flip-flop driven by lb1 and a flip-flop driven by lb4 is represented conceptually as dashed-line 38,100. As illustrated, skew is minimized between the two flip-flops by driving lb1 and lb4 via the same clock terminal (t4). The CDP creates distinct clock domains for the following types of clock nets: Primary clock nets; Clock nets driven by gated clock cells; Clock nets driven by clock selector cells; Pseudo clock domains (if floorplan driven clock partitioning has been performed); and Derived clock nets. Timing relationships between the leaf level buffers are used to create optimum timing driven partitions. A scoring function for a partition is a function of interconnect cost and timing cost. To determine setup/hold timing relationships between leaf level buffers, an abstract graph is used as illustrated in the figure, having edges between two leaf level buffers if a setup/hold path exists between elements driven by the two leaf level buffers. The weight of the edge is the number of setup/hold paths between the two leaf level buffers. As a result of top-down partitioning, the clock tree has two types of nodes, terminals and paths. A terminal represents a graph node that is processed by downstream modules for skew minimization. Each of the terminals has a pair of paths that represent the respective buffer path from the respective parent terminal to the respective pair of child terminals. Clock domain edges are analyzed so that clock clusters recursively propagate the clock edge (e.g. a rising edge or a falling edge) used by the clock pin clusters at leaf level. Thus only one of rise time or fall time is propagated for all intervening levels of logic cells (including buffers and non-buffers). During skew minimization (such as illustrated in FIG. 35) each internal terminal of a clock network is analyzed in a bottom-up visitation order and an ideal delay for each respective buffer pair is determined that will minimize the skew of the terminal. Skew minimization uses a successive approximation approach to determine types of buffer(s) and interconnect lengths associated with each of the buffers. During a first pass skew optimization (or minimization), a default input transition time is used to compute delays of all clock buffers. For each terminal, respective locations of buffer pairs to be placed are determined that would minimize skew for an entire sub-tree. If the skew cannot be minimized by placing the buffer pair between two child terminals, then an amount of meandering interconnect/buffers to minimize the skew is determined. An iterative skew improver portion of the CTS tool performs multi-pass skew computation and idealized delay allocation for each stage of a buffer tree. The skew improver performs a multi-pass optimization because skew minimization is done bottom-up but input transition is propagated top-down. Therefore during the first pass, a skew minimizer uses a default input transition for each buffer stage of a clock network and performs skew minimization at each level. Subsequently, a clock network timing update is performed that updates transition times at each level, top-down, using an estimated output load on each of the buffers of the network. A second pass of skew minimization is performed that uses the propagated input transition time at each of the clock buffers. Subsequent passes are performed (such as 1, 2, 3, 4, or 5 iterations) seeking convergence of the skew minimizer. Clock network timing is updated in accordance with buffer placement, delays of buffer gates, and interconnect delays. Since cell delays are functions of input transition time and phase, the clock network timing (arrival time and transition time) is relatively accurate to ensure that buffer cell delays computed at each of the terminals matches closely with post-routed-extracted delays. Transition time at an output of a gate is a function of input transition time at the gate and effective output load (Ceff) driven by the gate. The proper phase of transition times is propagated down a clock network to accurately estimate transition times and cell delays at a next level of the clock network. In some usage scenarios (such as an SAF-based design flow) buffers may not be placed at ideal locations (i.e. there is no logic block in a proper buffer position). Thus clock buffer placement is performed iteratively. Whenever a buffer is placed at a somewhat non-ideal location, the effect of that buffer placement is propagated throughout the clock sub-tree. A buffer placer module of the CTS tool inserts a pair of buffers at each terminal of a clock network. Unlike standard cell design flows where a buffer may be placed anywhere in a row of standard cell logic, structured ASICs are constrained in where buffer resources may be placed. Buffer placement is performed recursively down the clock tree. At each terminal, the buffer placer evaluates a finite number of buffer pair sites for suitability as a buffer pair of the respective terminal. The buffer pairs are located by using a search window around an ideal buffer pair location. The buffer placer uses a speculative scoring function to score each pair of buffers. Each buffer pair is scored on the basis of the objective function: buf_pair_cost=0.9*buf_delay_cost+0.1*buf_dist_cost; where buf_delay_cost=dd0*dd0+dd1*dd1+dd2*dd2; where dd0=(1−est_delay/ideal_delay) for the respective parent terminal; dd1=(1−est_delay/ideal_delay) for the respective left terminal; and dd2=(1−est_delay/ideal_delay) for the respective right terminal. Similarly, buf—dist_cost=dbb*dbb+msd1*msd1+msd2*msd2; and dbb=manhattan distance between the pair of buffer. Ideally the pair of buffers should be as close as possible to reduce any delay uncertainty between a parent buffer and respective buffer pairs. Using a dbb term penalizes any pair of buffers that are far apart. msd1(2)=distance between left/right buffer and merging segment. A merging segment is a line that goes between a pair of idealized buffer locations. The distance of the buffer location and the merge segment are measured. The idealized buffer locations for the downstream sub-tree are computed with the parent buffer being ideally placed on the merging segment. If actual placement of the buffer deviates too much from the idealized line segment then the estimates for the downstream terminal are no longer valid. When two sub-trees have considerable differences in accumulated insertion delays then delay buffers are inserted to match insertion delay at a parent terminal. Differences in insertion delays may occur in some usage scenarios where one branch of the clock sub-tree is a (relatively large) gated-clock sub-domain and remaining branches are relatively smaller gated or un-gated clock-sub-domains. Delay buffers are scored using an objective scoring function: delay—buf_cost=0.70*dcost*dcost+0.2*ncost*ncost+0.1*pcost*pcost; where dcost=(1−(accum_delay+incr_delay)/ideal_delay); ncost=(1−actual_length/ideal_length); and pcost=(1−path_remaining_length/path_ideal_remaining_length). Besides the delay cost (which has the highest weighting), delay buf_cost uses two other metrics to evaluate a candidate delay buffer. Ncost factors in any deviation from ideal length of an interconnect for a respective path, and pcost factors in deviation of path length from a respective ideal path length. If the skew minimizer determines that the path requires some amount of meandering interconnect to add extra delay at the buffer, then a dummy-load insertion technique is used to implement the incremental meandering wire resource. A dummy load inserter portion of the CTS tool searches for optimal dummy load sites (typically a low drive strength inverter) on an SAF-based chip and connects the buffer to the dummy load. The CTS tool balances for max and min corners simultaneously as optimum skew for a max corner is not the optimum skew for min corner. In some usage scenarios skew at the max corner typically affects the setup timing paths whereas clock skew for the min corner affects the hold time paths. During deskewing monitored by the CTS tool, timing for both max and min corners (also known as mixed mode) is considered, and the CTS tool uses scoring functions (as described elsewhere herein) that uses a weighted sum of max and min scoring functions. Post-routed-extracted parasitics are used to perform clock tree optimization. The clock optimization is used to achieve timing closure in designs having correlation issues with predicted clock skew and post-extracted clock skew. In some usage scenarios, the CTS tool achieves a high degree of correlation with post-extracted skew using several techniques as described elsewhere herein. The CTS tool performs several clock tree optimizations, such as replacement of a clock gating cell, replacement of terminal buffers, dummy load insertion, and swapping a CTS buffer for some other morphable element that may be implemented as a buffer. CONCLUSION Certain choices have been made in the description merely for convenience in preparing the text and drawings and unless there is an indication to the contrary the choices should not be construed per se as conveying additional information regarding structure or operation of the embodiments described. Examples of the choices include: the particular organization or assignment of the designations used for the figure numbering and the particular organization or assignment of the element identifiers (i.e., the callouts or numerical designators) used to identify and reference the features and elements of the embodiments. Although the foregoing embodiments have been described in some detail for purposes of clarity of description and understanding, the invention is not limited to the details provided. There are many embodiments of the invention. The disclosed embodiments are exemplary and not restrictive. It will be understood that many variations in construction, arrangement, and use are possible, which are consistent with the description and are within the scope of the claims of the issued patent. For example, interconnect and function-unit bit-widths, clock speeds, and the type of technology used are variable according to various embodiments in each component block. The names given to interconnect and logic are merely exemplary, and should not be construed as limiting the concepts described. The order and arrangement of flowchart and flow diagram process, action, and function elements are variable according to various embodiments. Also, unless specifically stated to the contrary, value ranges specified, maximum and minimum values used, or other particular specifications (such as integration techniques and design flow technologies), are merely those of the described embodiments, are expected to track improvements and changes in implementation technology, and should not be construed as limitations. Functionally equivalent techniques known in the art are employable instead of those described to implement various components, sub-systems, functions, operations, routines, and sub-routines. It is also understood that many functional aspects of embodiments are realizable selectively in either hardware (i.e., generally dedicated circuitry) or software (i.e., via some manner of programmed controller or processor), as a function of embodiment dependent design constraints and technology trends of faster processing (facilitating migration of functions previously in hardware into software) and higher integration density (facilitating migration of functions previously in software into hardware). Specific variations in various embodiments include, but are not limited to: differences in partitioning; different form factors and configurations; use of different operating systems and other system software; use of different interface standards, network protocols, or communication links; and other variations to be expected when implementing the concepts described herein in accordance with the unique engineering and business constraints of a particular application. The embodiments have been described with detail and environmental context well beyond that required for a minimal implementation of many aspects of the embodiments described. Those of ordinary skill in the art will recognize that some embodiments omit disclosed components or features without altering the basic cooperation among the remaining elements. It is thus understood that much of the details disclosed are not required to implement various aspects of the embodiments described. To the extent that the remaining elements are distinguishable from the prior art, components and features that are omitted are not limiting on the concepts described herein. All such variations in design comprise insubstantial changes over the teachings conveyed by the described embodiments. It is also understood that the embodiments described herein have broad applicability to other computing and networking applications, and are not limited to the particular application or industry of the described embodiments. The invention is thus to be construed as including all possible modifications and variations encompassed within the scope of the claims of the issued patent.
|
G
|
G06
|
G06F
|
17
|
50
|
|||
11856173
|
US20090072768A1-20090319
|
USE OF AN ACCELEROMETER TO CONTROL VIBRATOR PERFORMANCE
|
ACCEPTED
|
20090304
|
20090319
|
[]
|
H02P718
|
["H02P718"]
|
8084968
|
20070917
|
20111227
|
318
|
114000
|
69925.0
|
DUDA
|
RINA
|
[{"inventor_name_last": "Murray", "inventor_name_first": "Matthew J.", "inventor_city": "Raleigh", "inventor_state": "NC", "inventor_country": "US"}, {"inventor_name_last": "Eaton", "inventor_name_first": "William Chris", "inventor_city": "Cary", "inventor_state": "NC", "inventor_country": "US"}]
|
A mobile device includes a vibrator, an accelerometer that senses a parameter of rotation, and a processor. The vibrator includes a drive motor and a drive circuit. The accelerometer senses a speed of rotation of the vibrator. The processor analyzes the sensed speed of rotation and generates a drive voltage that is received by the drive circuit to adjust the drive motor to produce a pre-determined, desired rotational speed. In another embodiment, the accelerometer senses an amplitude of a vibration produced by the vibrator. The processor analyzes the sensed amplitude of a vibration and generates a drive voltage that is received by the drive circuit to adjust the drive motor to produce a pre-determined, desired vibration amplitude. The processor may also compare the sensed parameter with a pre-determined desired parameter of rotation and generate a signal responsive to a result of the comparison and based on stored vibrator calibration curves.
|
1. A mobile device comprising: a vibrator, the vibrator including a drive motor and a drive circuit; an accelerometer, the accelerometer sensing a speed of rotation of the vibrator; and a processor, the processor analyzing the sensed speed of rotation and generating a drive voltage that is received by the drive circuit to adjust the drive motor to produce a pre-determined, desired rotational speed. 2. The mobile device according to claim 1, wherein the mobile device comprises a mobile phone. 3. The mobile device according to claim 1, wherein the processor compares the speed of rotation with the pre-determined desired rotational speed and generates the drive voltage responsive to a result of the comparison. 4. The mobile device according to claim 1, wherein the processor compares the speed of rotation with the pre-determined desired rotational speed and generates the drive voltage responsive to a result of the comparison and based on stored vibrator calibration curves. 5. The mobile device according to claim 4, wherein the processor updates the stored vibrator calibration curves based on the result of the comparison. 6. The mobile device according to claim 1, wherein the accelerometer continually senses the speed of rotation of the vibrator and in response, the processor generates the drive voltage to control the drive circuit to maintain the drive motor at the pre-determined desired rotational speed. 7. The mobile device according to claim 1, wherein the accelerometer senses an amplitude of a vibration produced by the vibrator, the processor analyzing the sensed amplitude of a vibration and generating a drive voltage that is received by the drive circuit to adjust the drive motor to produce a pre-determined, desired vibration amplitude. 8. The mobile device according to claim 7, wherein the processor compares the amplitude of the vibration with the pre-determined desired vibration amplitude and generates the drive voltage responsive to a result of the comparison. 9. The mobile device according to claim 7, wherein the processor compares the amplitude of the vibration with the pre-determined desired vibration amplitude and generates the drive voltage responsive to a result of the comparison and based on stored vibrator calibration curves. 10. The mobile device according to claim 9, wherein the processor updates the stored vibrator calibration curves based on the result of the comparison. 11. The mobile device according to claim 9, wherein the accelerometer continually senses the amplitude of the vibration of the vibrator and in response, the processor generates the drive voltage to control the drive circuit to maintain the drive motor at the pre-determined desired vibration amplitude. 12. A method for controlling a vibrator in a mobile device comprising: sensing a speed of rotation of a vibrator; and generating a signal to control the vibrator to produce a pre-determined desired rotational speed responsive to the sensed speed of rotation. 13. The method according to claim 12, further comprising sensing the speed of rotation using an accelerometer. 14. The method according to claim 12, further comprising comparing the speed of rotation with the pre-determined desired speed of vibration and generating the signal responsive to a result of the comparison. 15. The method according to claim 12, further comprising comparing the speed of rotation with the pre-determined desired speed of rotation and generating the signal responsive to a result of the comparison and based on stored vibrator calibration curves. 16. The method according to claim 15, further comprising updating the stored vibrator calibration curves based on the result of the comparison. 17. The method according to claim 12, further comprising sensing an amplitude of a vibration produced by a vibrator and generating a signal to control the vibrator to produce a pre-determined desired vibration amplitude responsive to the sensed amplitude of the vibration. 18. The method according to claim 17, further comprising sensing the amplitude of the vibration using an accelerometer. 19. A mobile device comprising: a vibrator, the vibrator including a drive motor and a drive circuit; a sensor, the sensor sensing a parameter of rotation of the vibrator; and a processor, the processor analyzing the sensed parameter of rotation and generating a signal that is received by the drive circuit to adjust the drive motor to produce a pre-determined, desired parameter of rotation. 20. The mobile device according to claim 19, wherein the parameter of rotation comprises at least one of a speed of rotation or an amplitude of vibration.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>The present invention is related to controlling a vibrator in a mobile phone, and more specifically to use of an accelerometer to control vibrator performance. Mobile phones generally have a means of informing the user to incoming calls via silent alerting, e.g., vibrating. This is helpful in instances where an alerting sound is inappropriate or where an alerting sound is not adequate. Thus, tactile sensation can be used to make the mobile user aware of calls or other events, such as alarms, calendar reminders, etc. Many mobile phones use eccentric mass vibrator motors for silent alerting. Eccentric mass vibrator motors tend to be driven at a single direct current (DC) voltage in mobile phone handsets. This voltage is one of the main factors that determines the vibrator motor's rotational speed. Internal variation in the vibrator may cause the speed of one motor (at the phone's drive voltage) to rotate at a different speed than another vibrator from the same manufacturer. In addition, as eccentric mass vibrators are used they wear which causes the motors to speed up beyond their original functional speed. Humans are sensitive to different frequency ranges of vibration. Acceleration increases as rotational speed increases. However, beyond a certain rotational speed, the human perception of vibration begins to diminish. Thus, if a target rotational speed can be identified for a given vibrator/phone implementation such that this speed maximizes tactile sensation, it would be optimum if the vibrator motor always functioned at this rotational speed.
|
<SOH> BRIEF SUMMARY OF THE INVENTION <EOH>Embodiments of the present invention are related to a mobile device that includes a vibrator, the vibrator including a drive motor and a drive circuit, an accelerometer, the accelerometer sensing a speed of rotation of the vibrator; and a processor, the processor analyzing the sensed speed of rotation and generating a drive voltage that is received by the drive circuit to adjust the drive motor to produce a pre-determined, desired rotational speed. Embodiments of the present invention are also related to a method for controlling a vibrator in a mobile device that includes sensing a speed of rotation of a vibrator, and generating a signal to control the vibrator to produce a pre-determined desired rotational speed responsive to the sensed speed of rotation. Embodiments of the present invention are further related to a mobile device that includes a vibrator, the vibrator including a drive motor and a drive circuit, a sensor, the sensor sensing a parameter of rotation of the vibrator, and a processor, the processor analyzing the sensed parameter of rotation and generating a signal that is received by the drive circuit to adjust the drive motor to produce a pre-determined, desired parameter of rotation.
|
BACKGROUND OF THE INVENTION The present invention is related to controlling a vibrator in a mobile phone, and more specifically to use of an accelerometer to control vibrator performance. Mobile phones generally have a means of informing the user to incoming calls via silent alerting, e.g., vibrating. This is helpful in instances where an alerting sound is inappropriate or where an alerting sound is not adequate. Thus, tactile sensation can be used to make the mobile user aware of calls or other events, such as alarms, calendar reminders, etc. Many mobile phones use eccentric mass vibrator motors for silent alerting. Eccentric mass vibrator motors tend to be driven at a single direct current (DC) voltage in mobile phone handsets. This voltage is one of the main factors that determines the vibrator motor's rotational speed. Internal variation in the vibrator may cause the speed of one motor (at the phone's drive voltage) to rotate at a different speed than another vibrator from the same manufacturer. In addition, as eccentric mass vibrators are used they wear which causes the motors to speed up beyond their original functional speed. Humans are sensitive to different frequency ranges of vibration. Acceleration increases as rotational speed increases. However, beyond a certain rotational speed, the human perception of vibration begins to diminish. Thus, if a target rotational speed can be identified for a given vibrator/phone implementation such that this speed maximizes tactile sensation, it would be optimum if the vibrator motor always functioned at this rotational speed. BRIEF SUMMARY OF THE INVENTION Embodiments of the present invention are related to a mobile device that includes a vibrator, the vibrator including a drive motor and a drive circuit, an accelerometer, the accelerometer sensing a speed of rotation of the vibrator; and a processor, the processor analyzing the sensed speed of rotation and generating a drive voltage that is received by the drive circuit to adjust the drive motor to produce a pre-determined, desired rotational speed. Embodiments of the present invention are also related to a method for controlling a vibrator in a mobile device that includes sensing a speed of rotation of a vibrator, and generating a signal to control the vibrator to produce a pre-determined desired rotational speed responsive to the sensed speed of rotation. Embodiments of the present invention are further related to a mobile device that includes a vibrator, the vibrator including a drive motor and a drive circuit, a sensor, the sensor sensing a parameter of rotation of the vibrator, and a processor, the processor analyzing the sensed parameter of rotation and generating a signal that is received by the drive circuit to adjust the drive motor to produce a pre-determined, desired parameter of rotation. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is further described in the detailed description which follows in reference to the noted plurality of drawings by way of non-limiting examples of embodiments of the present invention in which like reference numerals represent similar parts throughout the several views of the drawings and wherein: FIG. 1 is a diagram of a mobile device according to an example embodiment of the present invention; FIG. 2 is a flowchart of a process for controlling a vibrator according to an example embodiment of the present invention; FIG. 3 is a flowchart of a process for controlling a vibrator according to another example embodiment of the present invention; FIG. 4 is a flowchart of a process for controlling a vibrator using a calibration profile according to an example embodiment of the present invention; FIG. 5 is a flowchart of a process for controlling a vibrator using a calibration profile according to another example embodiment of the present invention; FIG. 6 is a diagram of a vibrator calibration graph according to an example embodiment of the present invention; and FIG. 7 is a diagram of a vibrator calibration graph according to another example embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION As will be appreciated by one of skill in the art, the present invention may be embodied as a method, system, computer program product, or a combination of the foregoing. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may generally be referred to herein as a “system.” Furthermore, the present invention may take the form of a computer program product on a computer-usable storage medium having computer-usable program code embodied in the medium. Any suitable computer usable or computer readable medium may be utilized. The computer usable or computer readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer readable medium would include the following: an electrical connection having one or more wires; a tangible medium such as a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a compact disc read-only memory (CD-ROM), or other tangible optical or magnetic storage device; or transmission media such as those supporting the Internet or an intranet. Note that the computer usable or computer readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. In the context of this document, a computer usable or computer readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, platform, apparatus, or device. The computer usable medium may include a propagated data signal with the computer-usable program code embodied therewith, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted using any appropriate medium, including but not limited to the Internet, wireline, optical fiber cable, radio frequency (RF) or other means. Computer program code for carrying out operations of the present invention may be written in an object oriented, scripted or unscripted programming language such as Java, Perl, Smalltalk, C++ or the like. However, the computer program code for carrying out operations of the present invention may also be written in conventional procedural programming languages, such as the “C” programming language or similar programming languages. The present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. Alternatively, computer program implemented steps or acts may be combined with operator or human implemented steps or acts in order to carry out an embodiment of the invention. Embodiments according to the present invention control vibration motor characteristics using a sensor. To illustrate embodiments of the present invention, the sensor is an accelerometer, however, embodiments of the present invention are not limited by the use of an accelerometer as any type sensor that monitors the speed of rotation and/or an amplitude of a vibration signal is within the scope of the present invention. An accelerometer may be used to control the speed and/or amplitude of a vibration generator. The rotational speed of a vibrator may be sensed with the onboard accelerometer and, in response, an optimum drive voltage may be determined and fed back to a vibrator driver circuit in the accelerometer thus causing the vibration motor to produce a pre-determined optimum rotational speed. In other embodiments, an amplitude of a vibration signal of the vibrator may be sensed with the accelerometer and, in response, an optimum drive voltage may be determined and fed back to a vibrator driver circuit in the accelerometer thus causing the vibration motor to produce a pre-determined optimum amplitude. Generally, DC-motors increase in speed as the DC drive voltage supplied to them is increased. Embodiments according to the present invention may also be viable for use with linear travel vibrator transducers and multi-mode actuators. These devices can often be driven with a known frequency. However, their transducer sensitivity may vary based on the internal efficiency of their coil windings and magnetic motor. Thus, different vibration levels may be achieved with different samples of a given transducer. In a given phone design, there may be a maximum vibration level that is desired in a set of phone mechanics. Going beyond this level may increase sensation but also cause audible rattles and buzzes from associated phone mechanics. In certain cases, if the vibration transducer is in close proximity to electrical contacts or vibration sensitive components, there may be a maximum vibration level imposed by these constituent parts as well. In contrast, being too far below the maximum vibration limit may reduce the effectiveness of the vibration transducer. Therefore, in embodiments according to the present invention, when the limit of acceptable vibration is known in a handset, the use of an accelerometer to provide vibration feedback information to the vibration driver may be used to adjust each phone/motor combination independently. This adjustment may be used to help with operating the motor/vibration transducer at the maximum allowable vibration without exceeding predetermined vibration levels. According to embodiments of the present invention, vibrators that are driven by either DC (direct current) voltages or AC (alternating current) voltages may be monitored. An associated vibration frequency and/or amplitude of vibration of a vibrator may be monitored and controlled according to a desired frequency of vibration or amplitude of vibration signal. If the vibrator uses DC voltage to control the frequency of vibration, a DC voltage may be supplied to the vibrator to control the frequency of vibration (speed of rotation). If a vibrator is driven by an AC signal to control the frequency of vibration, the frequency is typically known based on the frequency of the AC signal used to drive the vibrator. Therefore, according to embodiments of the present invention, an accelerometer may be used to control an amplitude of the vibration signal where the accelerometer may monitor an amplitude of the vibration signal and supply appropriate AC voltages to a vibrator to ensure that the amplitude of a vibration signal generated by the vibrator is maintained at a desired amplitude. FIG. 1 shows a diagram of a mobile device according to an example embodiment of the present invention. The mobile device 100 may include a processor 101 interconnected to a transceiver 102 for transmitting and receiving information. The information may be text data, audio, video, other type data or a combination thereof. The processor 101 may also be connected to an accelerometer 103, a vibrator 104, and one or more memory devices 105. The vibrator may include a drive circuit 106, a drive motor 107, and a rotating mass 108. The processor 101 may receive information via the transceiver 102 that may require a vibration to be generated from the vibrator 104 (e.g., incoming call, incoming page, etc.). The processor may then send a drive signal to the drive circuit 106 in the vibrator 104 to cause the vibrator 104 to generate a vibration. Further, the processor may alternatively receive a signal from the accelerometer 103 that, in combination with some programming logic, results in a controlled voltage being sent to the drive circuit 106 in the vibrator 104 to cause the vibrator 104 to vibrate at a specific speed of rotation or a specific frequency. Since speed of rotation and frequency are interchangeable, either term may be used throughout the present disclosure. While not shown, in instances where the drive motor 107 is an AC-driven motor, there may be a frequency generator and associated components for driving the AC-driven motor at a desired frequency. As discussed above, embodiments of the present invention include a sensor associated with the vibrator for sensing operation of the vibrator. For illustration purposes, the sensor 103 is shown as an accelerometer for sensing vibration signals generated by the vibrator 104. The sensor 103 provides feedback regarding operation of the vibrator 104, and in particular, detects a level related to a vibration output by the vibrator 104. Either or both the frequency of vibration or amplitude of vibration may be monitored. Typically, where the vibrator 104 is driven by a DC motor, the sensed vibration signal may be analyzed for vibration frequency, and where the vibrator 104 is driven by an AC motor, the sensed vibration signal may be analyzed for the amplitude of the vibration signal. In the illustrated embodiment, the output of the sensor 103, in this case an accelerometer, is provided to the processor 101 for analysis and use in providing an appropriate drive signal (selected voltage or frequency) to the drive circuit 106 of the vibrator 104. In some embodiments, the processor 101 may use stored threshold values for vibration frequency and/or vibration amplitude. The processor 101 may compare the vibration signal to one or both of these threshold values and adjust the output to the drive circuit 106 accordingly. In other embodiments of the present invention, the processor 101 may use vibrator calibration curves stored in the memory 105 to determine what voltage or frequency the accelerometer 103 may need to generate to achieve a desired vibration signal from the vibrator 104. The vibrator calibration curves may be a single curve or multiple curves and may be established during or after manufacture of the vibrator. Further, the curves may be determined with the vibrator installed or not installed in a mobile device 100. The accelerometer 103 may monitor and sense a speed of rotation of the vibrator 104 and supply this sensed speed of rotation to the processor 101. The processor 101 may then compare the sensed speed received from the accelerometer 103 with a desired speed. The desired speed may be preset or may be dynamically inputted into the processor 101. Further, the desired speed, as noted previously, may be retrieved from vibrator calibration curves stored in a memory 105. Depending on the result of the comparison, the processor 101 may generate and send appropriate voltage levels to the drive circuit 106 to control the vibrator 104 to produce a desired speed of rotation of the drive motor 107 (i.e., associated with the desired vibration frequency). Therefore, as a vibrator ages and undergoes burn-in, any fluctuations in a desired vibration frequency may be immediately corrected and adjusted in order to maintain a desired vibration frequency (i.e., speed of rotation). The processor 101, after receiving the sensed speed of rotation of the vibrator 104 from the accelerometer 103, may also generate or update the stored vibrator calibration curves. Therefore, the vibration calibration curves may be kept updated based on knowing what past voltage levels supplied to the vibrator 104 produced what speeds of rotation or vibration frequencies. FIG. 2 shows a flowchart of a process for controlling a vibrator according to an example embodiment of the present invention. In the process 200, in block 201, a signal may be generated to initiate a vibration. In block 202, a vibration may be generated by a vibrator in response to the signal. In block 203, a speed of rotation of the vibrator (or frequency of vibration) may be sensed. In block 204, the sensed speed maybe compared with a desired speed. In block 205, it may be determined whether the sensed speed is the same as a desired speed, and if so, the process returns to block 203 where the speed of rotation of the vibrator is sensed. If the sensed speed is not the same as the desired speed based on the comparison in block 205, in block 206, it may be determined what appropriate correction is needed to obtain the desired speed. In this regard, it may be determined how far away, plus or minus, the sensed speed is from the desired speed and what voltage level may be needed to be sent to the vibrator to cause the vibrator to produce a sensed speed value that is the same as the desired speed. In block 207, an appropriate voltage may be sent to the vibrator based on the determined needed correction. In block 208, the speed of rotation (frequency of vibration) may be adjusted based on the voltage received and the process return to block 203, where the speed of rotation of the vibrator is sensed. FIG. 3 shows a flowchart of a process for controlling a vibrator according to another example embodiment of the present invention. In the process 300, in block 301, a signal to initiate a vibration may be generated. In this regard, an incoming call may be received, a pager may receive an incoming call, a reminder regarding a calendar/schedule entry, etc. that requires a vibration to be generated from the vibrator to alert a user or holder of the mobile device of the received communication. In block 302, a vibration may be generated by a vibrator in response to the signal. In block 303, an amplitude of a vibration from the vibrator may be sensed. In block 304, the sensed amplitude may be compared with a desired amplitude. In block 305, it may be determined whether the sensed amplitude is the same as the desired amplitude, and if so, the process returns to block 303 where an amplitude of a vibration of the vibrator may be again sensed. If the sensed amplitude is not the same as the desired amplitude as determined in block 305, in block 306, it may be determined what appropriate correction is needed. In this regard, it may be determined how far away, plus or minus, the sensed amplitude is from the desired amplitude and what voltage level may be needed to bring the sensed amplitude value to the desired amplitude. In block 307, an appropriate voltage may be sent to the vibrator based on the determined needed correction. In block 308, the amplitude may be adjusted based on the sent voltage, and the process return to block 303, where the amplitude of a vibration from the vibrator is sensed. FIG. 4 shows a flowchart of a process for controlling a vibrator using a calibration profile according to an example embodiment of the present invention. In the process 400, in block 401, a profile of voltages to rotational speed for a specific vibrator may be generated. The generated profile may be considered a vibrator calibration profile and may be used to determine what voltage should be supplied to the specific vibrator to achieve a desired rotational speed/vibration frequency. In block 402, the vibrator profile may be stored in a memory device. In block 403, a signal may be generated to initiate a vibration. In this regard, an incoming call may be received, a pager may receive an incoming call, a reminder regarding a calendar/schedule entry, etc. that requires a vibration to be generated from the vibrator to alert a user or holder of the mobile device of the received communication. In block 404, a vibration may be generated by the vibrator in response to the signal. In block 405, a speed of rotation/vibration frequency of the vibrator may be sensed. In block 406, the sensed speed of rotation may be compared with a desired speed. In block 407, it may be determined whether the sensed speed (i.e., vibration frequency) is the same as a desired speed (or desired vibration frequency), and if so, the process may return to block 405 where a speed of rotation of the vibrator may be sensed again. If the sensed speed is not the same as a desired speed, as determined in block 407, in block 408 it may be determined what appropriate correction is needed based on the vibrator profile. In this regard, the sensed speed may be analyzed to see how far away it is from the desired speed and how these two map onto the existing vibrator profile. The analysis may also include determining what new voltage level may need to be supplied to the vibrator in order to achieve the desired speed. The voltage may be increased or decreased accordingly. For example, if a voltage that corresponds to the desired speed according to the profile was supplied, but the sensed speed was different, using the profile, the voltage may be adjusted. In block 409, an appropriate voltage may be sent to the vibrator based on the determined correction. In block 410, the speed of rotation (vibration frequency) may be adjusted based on the voltage. In block 411, the vibrator profile may be revised/updated based on the previous voltage and sensed speed and the revised/updated profile stored. The process may then move to block 405 where a speed of the rotation of the vibrator may be again sensed. FIG. 5 shows a flowchart of a process for controlling a vibrator using a calibration profile according to another example embodiment of the present invention. In the process 500, in block 501, a profile of voltages to vibration signal amplitude for a vibrator may be generated. In block 502, the profile may be stored. In block 503, a signal may be generated to initiate a vibration from a vibrator. In block 504, a vibration may be generated by the vibrator in response to the signal. In block 505, an amplitude of a vibration of the vibrator may be sensed. In block 506, the sensed amplitude may be compared with a desired amplitude. In block 507, it may be determined if the sensed amplitude is the same as the desired amplitude, and if so, the process returns to block 505 where an amplitude of a vibration of the vibrator is again sensed. If the sensed amplitude is not the same as the desired amplitude, block 507, in block 508, an appropriate correction that is needed based on a vibrator profile may be determined. Similar to the speed of rotation correction determination, the sensed amplitude may be analyzed to determine how close or far away it is from the desired amplitude as well as what voltage was generated to produce the sensed amplitude, and then the vibrator profile used to determine what voltage should be supplied to the vibrator to produce the desired amplitude. For example, if a voltage that corresponds to the desired amplitude according to the profile was supplied, but the sensed amplitude was different, using the profile, the voltage may be adjusted. In block 509, an appropriate voltage may be sent to the vibrator based on the determined needed correction. In block 510, the amplitude may be adjusted based on the sent voltage. In block 511, the vibrator profile may be revised/updated based on the previous voltage used that produced the sensed amplitude, and the revised profile is then stored. The process may then return to block 505 where again an amplitude of a vibration of the vibrator may be sensed. FIG. 6 shows a diagram of a vibrator calibration graph according to an example embodiment of the present invention. The graph 600 may include a first axis 601 that represents a voltage supplied to a vibrator and a second axis 602 that represents an associated rotational speed or vibration frequency associated with a vibration generated by the vibrator at a specific voltage based on the intersection of the vibration frequency and voltage on a vibration curve 603. The graph 600 may include one or more vibration curves. In this example embodiment, a vibrator associated with the curve 603 may produce a vibration frequency of 140 hertz when a DC voltage of 2.7 volts is supplied to the vibrator. Although not shown, other voltages and frequencies may be displayed on this graph in order to determine what voltage needs to be supplied to a vibrator in order for the vibrator to produce a certain frequency of vibration. Should, at a later time, a supplied voltage of 2.7 volts produces a different frequency than the 140 hertz, the vibration curve 603 may be updated and adjusted accordingly. Further, the graph 600 may contain multiple vibration curves where one curve may be based on actual measurements from the vibrator and the other curves based on possible or estimated future vibrator characteristic variations over time. FIG. 7 shows a diagram of a vibrator calibration graph according to another example embodiment of the present invention. In this embodiment, a graph 700 may include one or more vibrator calibration curves 703. The graph 700 may include a first axis 701 that shows various voltages that may be supplied to a vibrator to produce specific amplitudes of a vibration signal. The graph 700 may also include a second axis 702 that shows various values of an amplitude of a vibration signal generated by a vibrator. Points on the calibration curve 703 where a specific voltage intersects with a specific amplitude denotes that this voltage may be supplied to the vibrator in order to produce this specific amplitude of the vibration signal. The calibration curve 703 may be updated where the curve looks different based on sensed amplitudes of vibrations being generated based on certain voltages supplied to the vibrator. In this example embodiment, a DC voltage of 2.7 volts being supplied to the vibrator may produce a vibration signal with an amplitude of 3 m/s2(meters/second2). Should, at a later time, a supplied voltage of 2.7 volts produce a different amplitude than the 3 m/s2, the vibration curve 703 may be updated and adjusted accordingly. Further, the graph 700 may contain multiple vibration curves where one curve may be based on actual measurements from the vibrator and the other curves based on possible or estimated future vibrator characteristic variations over time. The flowcharts and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art appreciate that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown and that the invention has other applications in other environments. This application is intended to cover any adaptations or variations of the present invention. The following claims are in no way intended to limit the scope of the invention to the specific embodiments described herein.
|
H
|
H02
|
H02P
|
7
|
18
|
|||
11911886
|
US20080152603A1-20080626
|
Antioxidants
|
ACCEPTED
|
20080612
|
20080626
|
[]
|
A61K844
|
["A61K844", "C07C21554", "A61Q1700", "A61Q1908", "A61Q1904", "C07C6984", "C07C22938"]
|
8106233
|
20071018
|
20120131
|
560
|
075000
|
75275.0
|
CUTLIFF
|
YATE
|
[{"inventor_name_last": "Rudolph", "inventor_name_first": "Thomas", "inventor_city": "Darmstadt", "inventor_state": "", "inventor_country": "DE"}, {"inventor_name_last": "Buchholz", "inventor_name_first": "Herwig", "inventor_city": "Frankfurt", "inventor_state": "", "inventor_country": "DE"}]
|
The present invention relates to the use of compounds of the formula (I), with radicals defined in the description, as antioxidants, to corresponding novel compounds and compositions, and to corresponding processes for the preparation of compounds and compositions.
|
1. A method of achieving an antioxidant effect comprising employing on an antioxidant, compounds of the formula I where Ar stands for an unsubstituted or mono- or polysubstituted aromatic ring or condensed ring systems having 6 to 18 C atoms, at least one ring of which has an aromatic character and in which one or two CH groups per ring may be replaced by C═O, N, O or S and one or two CH2 groups in a condensed ring system may be replaced by C═O or C═CH2, R1 stands for H or a branched or unbranched C1-30-alkyl or C1-30-hydroxyalkyl radical or a radical Ra or Rb where m stands for an integer from the range from 1 to 30, and A1-A3 each, independently of one another, stand for a benzyl radical or a —(CH2O)n(CH2)o(O)pH radical, where m and o each, independently of one another, stand for an integer from the range from 0 to 30, and p stands for 0 or 1, X stands for a group selected from —H, —CN, —C(═O)—R1 and —C(═O)-Z2-R1, Y stands for H or Ar, Z1 and Z2 each, independently of one another, stand for O, S, CR7R8, NR7 or a single bond, R7 and R8 are each, independently of one another, selected from H, OH, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, or salts of the compounds of the formula I, as antioxidants. 2. A method according to claim 1, characterised in that the compounds of the formula I are compounds of the formula Ia where R1, R7 and R8, Z1 and Z2, X and Y have the meaning given in claim 5, R2 to R6 are each, independently of one another, selected from H, OH, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, where one of the radicals R2 to R6 may also stand for a branched or unbranched C1-20-alkoxy or branched or unbranched C2-20-alkyleneoxy spacer which is bonded to an oligo- or polysiloxane chain via an Si atom, or salts of the compounds of the formula Ia. 3. A method according to claim 1 for the preparation of cosmetic or pharmaceutical, in particular dermatological compositions or of foods or food supplements or for the preparation of domestic products. 4. A method of claim 2, characterised in that R3 and R5 are each, independently of one another, selected from H, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, where R3 and R5 are each, independently of one another, preferably selected from straight-chain or branched C1- to C4-alkoxy groups, in particular methoxy, isopropoxy and tert-butoxy, and straight-chain or branched C1- to C6-alkyl groups, in particular methyl, isopropyl and tert-butyl, and R2, R4 and R6 are each, independently of one another, selected from H, OH, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, where R2, R4 and R6 are preferably selected from H and OH, and where one of the radicals R2 to R6 may also stand for a branched or unbranched C1-20-alkoxy or branched or unbranched C2-20-alkyleneoxy spacer which is bonded via an Si atom to an oligo- or polysiloxane chain, which in turn contains one or more compounds of the formula I. 5. A method of claim 2, characterised in that at least one group from R2, R4 and R6 stands for OH. 6. A method of claim 2, characterised in that Z2 stands for a single bond. 7. A method of claim 1, characterised in that R1 stands for a branched or unbranched C7-30-alkyl or C6-30-hydroxyalkyl radical. 8. A method of claim 2, characterised in that R4 stands for a branched or unbranched C1-20-alkoxy or branched or unbranched C2-20-alkyleneoxy spacer which is bonded via an Si atom to an oligo- or polysiloxane chain which contains one or more compounds of the formula I, where R4 preferably stands for a propanyloxy, isopropanyloxy, propenyloxy, isopropenyloxy or in particular an allyloxy spacer, where a silicon atom is preferably bonded to the 1-C or 2-C of the spacer double bond. 9. A method of claim 1, characterised in that X stands for —C(═O)-Z1-R1, where the two radicals -Z1-R1 are identical and R2 to R6 each, independently of one another, preferably stand for H, hydroxyl or methoxy. 10. A method of claim 1, characterised in that the at least one compound is selected from 4-hydroxyphenylpropionic acid, 2-ethylhexyl 4-hydroxyphenylpropionate, di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylmalonate, di-2-ethylhexyl 4-methoxybenzylmalonate, 2-ethylhexyl 4-methoxyphenylpropionate, 2-ethylhexyl 4-hydroxy-3,5-dimethoxyphenylpropionate, di-2-ethylhexyl 3,4,5-trimethoxybenzylmalonate, 2-ethylhexyl 4-hydroxy-3-methoxyphenylpropionate, di-2-ethylhexyl 4-hydroxy-3-methoxybenzylmalonate, di-2-ethylhexyl 3,4-dihydroxybenzylmalonate, 2-ethylhexyl 3,4-dihydroxyphenylpropionate, 3,4-dihydroxyphenylpropionic acid, phenethyl 3,4-dihydroxyphenylpropionate, 2-ethylhexyl 2-cyano-3,3-diphenylpropionate and oligo- and polysiloxanes which contain benzylmalonic acid derivatives or phenylpropionic acid derivatives, such as, preferably, diethyl p-benzylmalonate, bonded via propanyloxy, isopropanyloxy, propenyloxy, isopropenyloxy or allyloxy spacers. 11. A method of claim 1, characterised in that Z1 stands for NH, and R1 stands for a radical Ra or Rb where m stands for an integer from the range from 1 to 3, and A1-A3 each, independently of one another, stand for H or a radical —(CH2)o(O)pH, where o stands for 1, 2 or 3, and p stands for 0 or 1. 12. A method according to claim 11, characterised in that the compound is selected from compounds Ib to Iah and salts thereof, in particular chlorides thereof, 13. Compound of the formula I where Ar stands for an unsubstituted or mono- or polysubstituted aromatic ring or condensed ring systems having 6 to 18 C atoms, at least one ring of which has an aromatic character and in which one or two CH groups per ring may be replaced by C═O, N, O or S and one or two CH2 groups in a condensed ring system may be replaced by C═O or C═CH2, R1 stands for H or a branched or unbranched C1-30-alkyl or C1-30-hydroxyalkyl radical or a radical Ra or Rb where m stands for an integer from the range from 1 to 30, and A1-A3 each, independently of one another, stand for a benzyl radical or a —(CH2O)n(CH2)o(O)pH radical, where m and o each, independently of one another, stand for an integer from the range from 0 to 30, and p stands for 0 or 1, X stands for a group selected from —H, —CN, —C(═O)—R and —C(═O)-Z2-R1, Y stands for H or Ar, Z1 and Z2 each, independently of one another, stand for O, S, CR7R8, NR7 or a single bond, R7 and R8 are each, independently of one another, selected from H, OH, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, or salts of the compounds of the formula I. 14. Compound according to claim 13, characterised in that the compounds of the formula I are compounds of the formula Ia where R1, R7 and R8, Z1 and Z2, X and Y have the meaning given in claim 5, R2 to R6 are each, independently of one another, selected from H, OH, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, where one of the radicals R2 to R6 may also stand for a branched or unbranched C1-20-alkoxy or branched or unbranched C2-20-alkyleneoxy spacer which is bonded to an oligo- or polysiloxane chain via an Si atom, or salts of the compounds of the formula Ia. 15. Compound of the formula I or Ia according to claim 13, characterised in that Z1 stands for a single bond. 16. Compound of the formula Ia according to claim 14, characterised in that R3 and R5 are each, independently of one another, selected from straight-chain or branched C1- to C4-alkoxy groups, in particular methoxy, isopropoxy and tert-butoxy, and straight-chain or branched C1- to C6-alkyl groups, in particular methyl, isopropyl and tert-butyl, and R2, R4 and R6 are selected from H and OH. 17. Compound of the formula Ia according to claim 14, characterised in that at least one group from R2, R4 and R6 stands for OH. 18. Compound of the formula I or Ia according to claim 13, characterised in that R1 stands for a branched or unbranched C7-30-alkyl or C6-30-hydroxyalkyl radical. 19. Compound of the formula I or Ia according to claim 13, characterised in that X stands for —C(═O)-Z2-R1, where the two radicals -Z2-R1 are identical, and R2 to R6 each, independently of one another, preferably stand for H, hydroxyl or methoxy. 20. Composition comprising at least one vehicle which is suitable for cosmetic or pharmaceutical, in particular dermatological compositions, foods or food supplements or domestic products, and at least one compound of the formula I or Ia containing radicals according to claim 1. 21. Composition according to claim 20, characterised in that the compositions comprise one or more compounds of formula I or Ia in an amount of 0.01 to 20% by weight, preferably in an amount of 0.1 to 10% by weight. 22. Composition according to claim 1 for the protection of body cells against oxidative stress, in particular for reducing skin ageing, characterised in that it preferably comprises one or more further antioxidants and/or vitamins, preferably selected from vitamin A palmitate, retinol, vitamin C and derivatives thereof, DL-α-tocopherol, tocopherol E acetate, nicotinic acid, pantothenic acid and biotin. 23. Composition according to claim 1, characterised in that the composition comprises at least one self-tanning agent, where the at least one self-tanning agent is preferably selected from trioses and tetroses, and at least one self-tanning agent is particularly preferably dihydroxyacetone. 24. Use of compounds of formula I or Ia containing radicals according to claim 1 for product protection, in particular for the protection of oxidation-sensitive formulation constituents, such as organic or inorganic dyes, antioxidants, vitamins, perfume components, oil components or matrix constituents, such as emulsifiers, thickeners, film formers and surfactants. 25. Use of compounds of formula I or Ia containing radicals according to claim 1 for pigmentation control, in particular for lightening skin areas. 26. Process for the preparation of a composition, characterised in that a compound of the formula I or Ia containing radicals according to claim 1 is mixed with a vehicle which is suitable cosmetically or pharmaceutically or for foods or food supplements or for domestic products. 27. Process for the preparation of a compound of the formula I according to claim 5, characterised in that at least one compound of the formula I ena or I enb where the radicals Ar, X, Y, Z1 and Z2 and R1 correspond to those of the desired formula I, is hydrogenated.
|
The present invention relates to the use of compounds as antioxidants or for product protection or for pigmentation control, to corresponding novel compounds and compositions, and to corresponding processes for the preparation of compounds and compositions. One area of application of the compounds according to the invention is, for example, cosmetics. The object of care cosmetics is wherever possible to obtain the impression of youthful skin. In principle, there are various ways of achieving this object. For example, existing skin damage, such as irregular pigmentation or the formation of wrinkles, can be compensated for by covering powders or creams. Another approach is to protect the skin against environmental influences which lead to permanent damage and thus ageing of the skin. The idea is therefore to intervene in a preventative manner and thus to delay the ageing process. An example of this are UV filters, which, as a result of absorption of certain wavelength ranges, pre-vent or at least reduce skin damage. Whereas in the case of UV filters the damaging event, the UV radiation, is screened off by the skin, another route involves attempting to support the skin's natural defence or repair mechanisms against the damaging event. Finally, a further approach involves compensating for the weakening defence functions of the skin against harmful influences with increasing age by externally supplying substances which are able to replace this diminishing defence or repair function. For example, the skin has the ability to scavenge free radicals generated by external or internal stress factors. This ability diminishes with increasing age, causing the ageing process to accelerate with increasing age. A further difficulty in the preparation of cosmetics is that active ingredients which are intended to be incorporated into cosmetic compositions are frequently unstable and can be damaged in the composition. The damage may be caused, for example, by a reaction with atmospheric oxygen or by absorption of UV rays. The molecules damaged in this way may, for example, change their colour and/or lose their activity through their structural change. Corresponding difficulties generally occur in the preparation, storage or use of compositions comprising oxidation-sensitive ingredients. A known way of dealing with the problems described consists in adding antioxidants to the compositions. According to CD Römpp Chemie Lexikon [CD Römpp Lexicon of Chemistry]—Version 1.0, Stuttgart/New York: Georg Thieme Verlag 1995, antioxidants are compounds which inhibit or prevent undesired changes in the substances to be protected caused by the action of oxygen, inter alia oxidative processes. Areas of application are, for example, in plastics and rubber for protection against ageing; in fats for protection against rancidity, in oils, cattle feeds, automotive gasoline and jet fuels for protection against gumming, in transformer and turbine oil against sludge formation, and in flavours against odour impairment. Compounds that are effective as antioxidants are, inter alia, phenols, hydroquinones, pyrocatechols, aromatic compounds and amines, each of which are substituted by sterically hindering groups, and metal complexes thereof. According to Römpp, the action of the antioxidants usually consists in that they act as free-radical scavengers for the free radicals which arise during autoxidation. However, there continues to be a demand for skin-tolerated antioxidants which are also suitable for use in skin-care compositions. The object of the invention is therefore to provide a composition which has a protective action against UV rays and/or exerts a protective action against oxidative stress on body cells and/or counters skin ageing. The present invention therefore relates firstly to the use of compounds of the formula I where Ar stands for an unsubstituted or mono- or polysubstituted aromatic ring or condensed ring systems having 6 to 18 C atoms, at least one ring of which has an aromatic character and in which one or two CH groups per ring may be replaced by C═O, N, O or S and one or two CH2 groups in a condensed ring system may be replaced by C═O or C═CH2, R1 stands for H or a branched or unbranched C1-30-alkyl or C1-30-hydroxyalkyl radical or a radical Ra or Rb where m stands for an integer from the range from 1 to 30, and A1-A3 each, independently of one another, stand for a benzyl radical or a —(CH2O)n(CH2)o(O)pH radical, where m and o each, independently of one another, stand for an integer from the range from 0 to 30, and p stands for 0 or 1, X stands for a group selected from —H, —CN, —C(═O)—R1 and —C(═O)-Z2-R1, Y stands for H or Ar, Z1 and Z2 each, independently of one another, stand for O, S, CR7R8, NR7 or a single bond, R7 and R8 are each, independently of one another, selected from H, OH, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, or salts of the compounds of the formula I. Preference is given in accordance with the invention to the use of compounds of the formula Ia where R1, R7 and R8, Z1 and Z2, X and Y have the meaning given in claim 5, R2 to R6 are each, independently of one another, selected from H, OH, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, where one of the radicals R2 to R6 may also stand for a branched or unbranched C1-20-alkoxy or branched or unbranched C2-20-alkyleneoxy spacer which is bonded to an oligo- or polysiloxane chain via an Si atom, or salts of the compounds of the formula Ia. In a particularly preferred embodiment of the present invention, Z1 in the compound of the formula Ia stands for a single bond. In this case, the formula Ia is simplified to It may furthermore be particularly preferred in accordance with the invention for Counterions which can be employed here for salts according to the invention are all anions which are acceptable for the corresponding application. Salts of strong acids are advantageous here. It is particularly preferred in accordance with the invention for the salts to be chlorides or bromides. The compounds described can be used in accordance with the invention as active ingredient for topical application or for the preparation of cosmetic or dermatological compositions or for the preparation of domestic products. The compounds described can be employed for product protection. For the purposes of this application, product protection means, in particular, the protection of oxidation-sensitive formulation constituents, such as organic or inorganic dyes, antioxidants, vitamins, perfume components, oil components or matrix constituents, such as emulsifiers, thickeners, film formers and surfactants. This application relates to the corresponding use. The invention also relates to the use of the compounds for the preparation of cosmetic or pharmaceutical, in particular dermatological compositions or of foods or food supplements or for the preparation of domestic products. The present invention furthermore relates to the novel compounds of the formula I or Ia. Preference is given here to the use of compounds of the formula I or Ia in which R3 and R5 are each, independently of one another, selected from H, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, where R3 and R5 are each, independently of one another, preferably selected from straight-chain or branched C1- to C4-alkoxy groups, in particular methoxy, isopropoxy and tert-butoxy, and straight-chain or branched C1- to C6-alkyl groups, in particular methyl, isopropyl and tert-butyl, and R2, R4 and R6 are each, independently of one another, selected from H, OH, straight-chain or branched C1- to C20-alkoxy groups, straight-chain or branched C1- to C20-alkyl groups, straight-chain or branched C3- to C20-alkenyl groups, straight-chain or branched C1- to C20-hydroxyalkyl groups, where the hydroxyl group may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, straight-chain or branched C1- to C20-hydroxyalkoxy groups, where the hydroxyl group(s) may be bonded to a primary or secondary carbon atom of the chain and furthermore the alkyl chain may also be interrupted by oxygen, where R2, R4 and R6 are preferably selected from H and OH, and where one of the radicals R2 to R6 may also stand for a branched or unbranched C1-20-alkoxy or branched or unbranched C2-20-alkyleneoxy spacer which is bonded via an Si atom to an oligo- or polysiloxane chain, which in turn contains one or more compounds of the formula I. In a variant of the invention, particular preference may be given to the use of at least one compound of the formula I which is characterised in that at least one group from R2, R4 and R6 stands for OH. These compounds exhibit a particularly pronounced antioxidative performance. In a further variant of the invention, particular preference may be given to the use of at least one compound of the formula I which is characterised in that at least one group from R3 and R5 stands for t-butyl. These compounds exhibit a particularly pronounced antioxidative performance. Preference may furthermore be given in accordance with the invention to the use of at least one compound of the formula I or Ia containing long-chain hydrocarbon radicals, in particular branched long-chain hydrocarbon radicals. These compounds are often particularly readily miscible with vehicles, such as, in particular, oils, and can thus be employed particularly easily in formulations. It is particularly preferred in this variant of the invention for R1 to stand for a branched or unbranched C7-30-alkyl or C6-30-hydroxyalkyl radical. In a further variant of the invention, it may be preferred to use compounds of the formula I or Ia which are characterised in that R4 stands for a branched or unbranched C1-20-alkoxy or branched or unbranched C2-20-alkyleneoxy spacer which is bonded via an Si atom to an oligo- or polysiloxane chain which contains one or more compounds of the formula I, where R4 preferably stands for a propanyloxy, isopropanyloxy, propenyloxy, isopropenyloxy or in particular an allyloxy spacer, where a silicon atom is preferably bonded to the 1-C or 2-C of the spacer double bond. It may furthermore be preferred in accordance with the invention to use at least one compound of the formula I in which X stands for —C(═O)-Z2-R1, where the two radicals -Z2-R1 are identical and R2 to R6 each, independently of one another, preferably stand for H, hydroxyl or methoxy. Particular preference is given here to the use of at least one compound of the formula I which is selected from 4-hydroxyphenylpropionic acid, 2-ethylhexyl 4-hydroxyphenylpropionate, di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylmalonate, di-2-ethylhexyl 4-methoxybenzylmalonate, 2-ethylhexyl 4-methoxyphenylpropionate, 2-ethylhexyl 4-hydroxy-3,5-di-methoxyphenylpropionate, di-2-ethylhexyl 3,4,5-trimethoxybenzylmalonate, 2-ethylhexyl 4-hydroxy-3-methoxyphenylpropionate, di-2-ethylhexyl 4-hydroxy-3-methoxybenzylmalonate, di-2-ethylhexyl 3,4-dihydroxybenzylmalonate, 2-ethylhexyl 3,4-dihydroxyphenylpropionate, 3,4-dihydroxyphenylpropionic acid, phenethyl 3,4-dihydroxyphenylpropionate, 2-ethylhexyl 2-cyano-3,3-diphenylpropionate and oligo- and polysiloxanes which contain benzylmalonic acid derivatives or phenylpropionic acid derivatives, such as, preferably, diethyl p-benzylmalonate, bonded via propanyloxy, isopropanyloxy, propenyloxy, isopropenyloxy or allyloxy spacers. It may be particularly preferred here for the compounds 2-ethylhexyl 4-hydroxy-3,5-di-t-butylphenylpropionate, ethyl 4-hydroxy-3,5-di-t-butylphenylpropionate, methyl 4-hydroxy-3,5-di-t-butylphenylpropionate, 2-ethylhexyl 4-hydroxy-3-t-butylphenylpropionate, ethyl 4-hydroxy-3-t-butylphenylpropionate, methyl 4-hydroxy-3-t-butylphenylpropionate, ethyl 4-hydroxy-3-methoxyphenylpropionate, methyl 4-hydroxy-3-methoxyphenylpropionate, ethyl 4-hydroxy-3,5-dimethoxyphenylpropionate, methyl 4-hydroxy-3,5-dimethoxyphenylpropionate, diethyl 4-hydroxy-3-methoxybenzylmalonate, diethyl 4-hydroxy-3,5-di-t-butylbenzylmalonate, dimethyl 4-hydroxy-3,5-di-t-butylbenzylmalonate not to be used in accordance with the invention. It may furthermore be preferred in accordance with the invention for at least one compound of the formula I in which Z1 stands for NH, and X stands for —C(═O)-Z2-R1, where the two radicals -Z2-R1 are identical, and R2 to R6 each, independently of one another, preferably stand for H, hydroxyl or methoxy, to be used. Preference is furthermore given to the use of compounds of the formula I in which Z1 stands for NH, and R1 stands for a radical Ra or Rb where m stands for an integer from the range from 1 to 3, and A1-A3 each, independently of one another, stand for a radical —(CH2)o(O)pH, where o stands for 1, 2 or 3, and p stands for 0 or 1. Particular preference is furthermore given in accordance with the invention to the use of compounds selected from compounds Ib to Iah and salts thereof, in particular chlorides thereof, The invention furthermore relates to compositions comprising at least one compound of the formula I. The compositions are usually either compositions which can be applied topically, for example cosmetic or dermatological formulations, or foods or food supplements or domestic products. In this case, the compositions comprise a cosmetically or dermatologically, food-suitable or domestic product-suitable vehicle and, depending on the desired property profile, optionally further suitable ingredients. Advantages of the compounds according to the invention or the use of compounds according to the invention or the compositions according to the invention may, in particular, be the following: an antioxidant action against free radicals, which are induced, for example, by UV light or thermolytic processes, such as smoking, such as, for example, against the superoxide free-radical anion or the NO free radical, or against reactive oxygen species, such as, for example, against singlet oxygen and peroxides, preferred compounds combine a strong antioxidant activity with high molecular stability, a product-stabilising action on cosmetic, pharmaceutical, in particular dermatological products or domestic products or foods and food supplements, in particular those which comprise dyes, consistency sub-stances or odour substances, preferred compounds of the formula I are suitable as oil component in compositions, preferred compounds of the formula I are suitable for improving pharmaceutical properties, such as, for example, the skin feel, of compositions, preferred compounds of the formula I exhibit good solubility and solvent properties, preferably, for example, as solvents for crystalline components, a preferred group of compounds according to the invention can also cause skin tanning or improve the action of skin-tanning substances, such as dihydroxyacetone, well tolerated by the skin, in particular in the case of the ammonium compounds of the formula I, the adsorption behaviour onto keratinic fibres, such as, in particular, hair, is excellent, a product-stabilising action on pigments and surface coatings, preferred compounds of the formula I are suitable for the production or boosting of light protection factors, such as LSF, SPF, PPD or IPD, or free-radical protection factors, a stabilising action on autooxidisable polyethylene glycol (PEG) or polyglycerin (PG) derivatives, such as, in particular, PEG- or PG-containing emulsifiers, as mentioned below in this application, or a reduction in the damaging action of the degradation products of autooxidisable polyethylene glycol (PEG) or polyglycerin (PG) derivatives, a stabilising action on colorants, consistency substances or odour substances, or on antioxidants or vitamins, and UV filters as well as titanium dioxide-containing pigments, in particular in cosmetic, pharmaceutical, in particular dermatological products or domestic products or foods and food supplements, while most antioxidants become ineffective after reaction with free radicals, preferred compounds of the formula I exhibit a UV-filtering action after this reaction and thus continue their protective function, preferred compounds according to the invention having antioxidant properties can also be employed for pigmentation control since they can have a lightening action on skin areas. In addition, preferred compounds of those described here are colourless or only weakly coloured and thus do not result in discoloration of the compositions, or only do so to a minor extent. As already stated above, the present invention furthermore relates to compositions comprising at least one vehicle which is suitable for cosmetic or dermatological compositions or domestic products and at least one compound of the above-mentioned formula I or Ia. It may be particularly preferred in accordance with the invention for the composition to comprise at least one compound of the formula I ena or I enb where the radicals Ar, X, Y, Z1 and Z2 and R1 each, independently of one another and independently of the radicals of the compounds of the formula I, have the meaning indicated above for the compounds of the formula I. It is particularly preferred here for the composition to comprise at least one compound of the formula Ia ena or Ia enb where the radicals X, Y, Z1 and Z2 and R1-R6 each, independently of one another and independently of the radicals of the compounds of the formula Ia, have the meaning indicated above for the compounds of the formula Ia. It is particularly preferred here for the radicals X, Y, Z1 and Z2 and R1-R6 in the at least one compound of the formula I and the at least one compound of the formula I ena or I enb or the at least one compound of the formula Ia and the at least one compound of the formula Ia ena or Ia enb to be identical. In this case, the compound of the formula I or Ia can simultaneously serve as reservoir for the UV absorption potential of the compound of the formula I ena or I enb or Ia ena or Ia enb. In other words, the use of the compounds of the formula I or Ia thus facilitates a reduction in the use concentration of the UV filter of the formula I ena or I enb. The adjustment of the use concentration presents the person skilled in the art with absolutely no difficulties. It is particularly preferred here for at least one compound of the formula I ena or I enb or Ia ena or Ia enb to be a compound selected from 4 hydroxycinnamic acid, 2-ethylhexyl 4-hydroxycinnamate, di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylidenemalonate, di-2-ethylhexyl 4-methoxybenzylidenemalonate, 2-ethylhexyl 4-methoxycinnamate, 2-ethylhexyl 4-hydroxy-3,5-dimethoxycinnamate, di-2-ethylhexyl 3,4,5-trimethoxybenzylidenemalonate, 2-ethylhexyl 4-hydroxy-3-methoxycinnamate, di-2-ethylhexyl 4-hydroxy-3-methoxybenzylidenemalonate, di-2-ethylhexyl 3,4-dihydroxybenzylidenemalonate, 2-ethylhexyl 3,4-dihydroxycinnamate, 3,4-dihydroxycinnamic acid, phenethyl 3,4-dihydroxycinnamate, 2-ethylhexyl 2-cyano-3-phenylcinnamate and oligo- and polysiloxanes which contain benzylidene-malonic acid derivatives or cinnamic acid derivatives, such as, preferably, diethyl p-benzylidenemalonate, bonded via propanyloxy, isopropanyloxy, propenyloxy, isopropenyloxy or allyloxy spacers. The compounds of the formula Ii or Ia are typically employed in accordance with the invention in amounts of 0.01 to 20% by weight, preferably in amounts of 0.1% by weight to 10% by weight and particularly preferably in amounts of 1 to 8% by weight. The person skilled in the art is presented with absolutely no difficulties in selecting the amounts appropriately depending on the intended action of the composition. In order that the compounds according to the invention are able to develop their positive action as free-radical scavengers on the skin particularly well, it may be preferred to allow the compounds according to the invention to penetrate into deeper skin layers. Several possibilities are available for this purpose. Firstly, the compounds according to the invention can have an adequate lipophilicity in order to be able to penetrate through the outer skin layer into epidermal layers. As a further possibility, corresponding transport agents, for example liposomes, which enable transport of the compounds according to the invention through the outer skin layers may also be provided in the composition. Finally, systemic transport of the compounds according to the invention is also conceivable. The composition is then designed, for example, in such a way that it is suitable for oral administration. In general, the substances of the formula I act as free-radical scavengers. Free radicals of this type are not generated exogenously only by sunlight, but also by the action of reactive substances, such as ozone, nitrogen oxides (for example cigarette smoke) or exposure to heavy metals (for example in the food). Further examples are anoxia, which blocks the flow of electrons upstream of the cytochrome oxidases and causes the formation of superoxide free-radical anions; inflammation associated, inter alia, with the formation of superoxide anions by the membrane NADPH oxidase of the leucocytes, but also associated with the formation (through disproportionation in the presence of iron(II) ions) of the hydroxyl free radicals and other reactive species which are normally involved in the phenomenon of phagocytosis; and lipid autoxidation, which is generally initiated by a hydroxyl free radical and produces lipidic alkoxy free radicals and hydroperoxides. Owing to these properties, the compounds and compositions according to the invention are, in general, suitable for immune protection and for the protection of DNA and RNA. In particular, the compounds and compositions are suitable for the protection of DNA and RNA against oxidative attack, against free radicals and against damage due to radiation, in particular UV radiation. A further advantage of the compounds and compositions according to the invention is cell protection, in particular protection of Langerhans cells against damage due to the above-mentioned influences. All these uses and the use of the compounds according to the invention for the preparation of compositions which can be employed correspondingly are expressly also a subject-matter of the present invention. In particular, preferred compounds and compositions according to the invention are also suitable for the treatment of skin diseases associated with a defect in keratinisation which affects differentiation and cell proliferation, in particular for the treatment of acne vulgaris, acne comedonica, polymorphic acne, acne rosaceae, nodular acne, acne conglobata, age-induced acne, acne which arises as a side effect, such as acne solaris, medicament-induced acne or acne professionalis, for the treatment of other defects in keratinisation, in particular ichthyosis, ichthyosiform states, Darier's disease, keratosis palmoplantaris, leukoplakia, leukoplakiform states, herpes of the skin and mucous membrane (buccal) (lichen), for the treatment of other skin diseases associated with a defect in keratinisation and which have an inflammatory and/or immunoallergic component and in particular all forms of psoriasis which affect the skin, mucous membranes and fingers and toenails, and psoriatic rheumatism and skin atopy, such as eczema or respiratory atopy, or hypertrophy of the gums, it furthermore being possible for the compounds to be used for some inflammation which is not associated with a defect in keratinisation, for the treatment of all benign or malignant excrescence of the dermis or epidermis, which may be of viral origin, such as verruca vulgaris, verruca plana, epidermodysplasia verruciformis, oral papillomatosis, papillomatosis florida, and excrescence which may be caused by UV radiation, in particular epithelioma baso-cellulare and epithelioma spinocellulare, for the treatment of other skin diseases, such as dermatitis bullosa and diseases affecting the collagen, for the treatment of certain eye diseases, in particular corneal diseases, for overcoming or combating light-induced skin ageing associated with ageing, for reducing pigmentation and keratosis actinica and for the treatment of all diseases associated with normal ageing or light-induced ageing, for the prevention or healing of wounds/scars of atrophy of the epidermis and/or dermis caused by locally or systemically applied corticosteroids and all other types of skin atrophy, for the prevention or treatment of defects in wound healing, for the prevention or elimination of stretch marks caused by pregnancy or for the promotion of wound healing, for combating defects in sebum production, such as hyperseborrhoea in acne or simple seborrhoea, for combating or preventing cancer-like states or pre-carcinogenic states, in particular promyelocytic leukaemia, for the treatment of inflammatory diseases, such as arthritis, for the treatment of all virus-induced diseases of the skin or other areas of the body, for the prevention or treatment of alopecia, for the treatment of skin diseases or diseases of other areas of the body with an immunological component, for the treatment of cardiovascular diseases, such as arteriosclerosis or hypertension, and of non-insulin-dependent diabetes, for the treatment of skin problems caused by UV radiation. The antioxidant actions of the compounds according to the invention can be demonstrated, for example, by means of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. 2,2-Diphenyl-1-picrylhydrazyl is a free radical which is stable in solution. The unpaired electron results in a strong absorption band at 515 nm, and the solution has a dark-violet colour. In the presence of a free-radical scavenger, the electron is paired, the absorption disappears, and the decoloration proceeds stoichiometrically taking into account the electrons taken up. The absorbance is measured in a photometer. The anti-free-radical property of the substance to be tested is determined by measuring the concentration at which 50% of the 2,2-diphenyl-1-picrylhydrazyl employed has reacted with the free-radical scavenger. This concentration is expressed as EC50, a value which should be regarded as a property of the substance under the given measurement conditions. The substance investigated is compared with a standard (for example tocopherol). The EC50 value here is a measure of the capacity of the respective compound to scavenge free radicals. The lower the EC50 value, the higher the capacity to scavenge free radicals. For the purposes of this invention, the expression “a large or high capacity to scavenge free radicals” is used if the EC50 value is lower than that of tocopherol. A further important aspect for the action of the antioxidants is the time in which this EC50 value is achieved. This time, measured in minutes, gives the TEC50 value, which allows a conclusion to be drawn on the rate at which these antioxidants scavenge free radicals. For the purposes of this invention, antioxidants which achieve this value within less than 60 minutes are regarded as fast, those which only achieve the EC50 value after more than 120 minutes are regarded as having a delayed action. The anti-free-radical efficiency (AE) (described in C. Sanchez-Moreno, J. A. Larrauri and F. Saura-Calixto in J. Sci. Food Agric. 1998, 76(2), 270-276) is given by the above-mentioned quantities in accordance with the following relationship: AE = 1 EC 50 T EC 50 A low AE (×103) is in the range up to about 10, a moderate AE is in the range from 10 to 20 and a high AE has in accordance with the invention values above 20. It may be particularly preferred in accordance with the invention to combine fast-acting antioxidants with those having a slow or time-delayed action. Typical weight ratios of the fast-acting antioxidants to time-delayed antioxidants are in the range from 10:1 to 1:10, preferably in the range from 10:1 to 1:1, and for skin-protecting compositions particularly preferably in the range from 5:1 to 2:1. In other compositions which are likewise preferred in accordance with the invention, it may, however, be advantageous for the purposes of action optimisation for more time-delayed anti-oxidants than fast-acting antioxidants to be present. Typical compositions then exhibit weight ratios of the fast-acting antioxidants to time-delayed antioxidants in the range from 1:1 to 1:10, preferably in the range from 1:2 to 1:8. The protective action against oxidative stress or against the effect of free radicals can thus be further improved if the compositions comprise one or more further antioxidants, the person skilled in the art being presented with absolutely no difficulties in selecting suitably fast-acting or time-delayed anti oxidants. In a preferred embodiment of the present invention, the composition is therefore a composition for the protection of body cells against oxidative stress, in particular for reducing skin ageing, characterised in that it preferably comprises one or more further antioxidants besides the one or more compounds of the formula I. There are many proven substances known from the specialist literature which can be used as antioxidants, for example amino acids (for example glycine, histidine, tyrosine, tryptophan) and derivatives thereof, imidazoles (for example urocanic acid) and derivatives thereof, peptides, such as D,L-carnosine, D-carnosine, L-carnosine and derivatives thereof (for example anserine), carotinoids, carotenes (for example α-carotene, β-carotene, lycopene) and derivatives thereof, chlorogenic acid and derivatives thereof, lipoic acid and derivatives thereof (for example dihydrolipoic acid), aurothioglucose, propylthiouracil and other thiols (for example thioredoxin, glutathione, cysteine, cystine, cystamine and the glycosyl, N-acetyl, methyl, ethyl, propyl, amyl, butyl and lauryl, palmitoyl, oleyl, γ-linoleyl, cholesteryl and glyceryl esters thereof) and salts thereof, dilauryl thiodipropionate, distearyl thiodipropionate, thiodipropionic acid and derivatives thereof (esters, ethers, peptides, lipids, nucleotides, nucleosides and salts), and sulfoximine compounds (for example buthionine sulfoximines, homocysteine sulfoximine, buthionine sulfones, penta-, hexa- and hepta-thionine sulfoximine) in very low tolerated doses (for example pmol to μmol/kg), and also (metal) chelating agents, (for example α-hydroxy fatty acids, palmitic acid, phytic acid, lactoferrin), α-hydroxy acids (for example citric acid, lactic acid, malic acid), humic acid, bile acid, bile extracts, bilirubin, biliverdin, EDTA, EGTA and derivatives thereof, unsaturated fatty acids and derivatives thereof, vitamin C and derivatives (for example ascorbyl palmitate, magnesium ascorbyl phosphate, ascorbyl acetate), tocopherols and derivatives (for example vitamin E acetate), vitamin A and derivatives (for example vitamin A palmitate), and coniferyl benzoate of benzoin resin, rutinic acid and derivatives thereof, α-glycosyl rutin, ferulic acid, furfurylideneglucitol, carnosine, butylhydroxytoluene, butylhydroxyanisole, nordihydroguaiaretic acid, trihydroxybutyrophenone, quercetin, uric acid and derivatives thereof, mannose and derivatives thereof, zinc and derivatives thereof (for example ZnO, ZnSO4), selenium and derivatives thereof (for example selenomethionine), stilbenes and derivatives thereof (for example stilbene oxide, trans-stilbene oxide). Mixtures of antioxidants are likewise suitable for use in the cosmetic compositions according to the invention. Known and commercial mixtures are, for example, mixtures comprising, as active ingredients, lecithin, L-(+)-ascorbyl palmitate and citric acid (for example Oxynex® AP), natural tocopherols, L-(+)-ascorbyl palmitate, L-(+)-ascorbic acid and citric acid (for example Oxynex® K LIQUID), tocopherol extracts from natural sources, L-(+)-ascorbyl palmitate, L-(+)-ascorbic acid and citric acid (for example Oxynex® L LIQUID), DL-α-tocopherol, L-(+)-ascorbyl palmitate, citric acid and lecithin (for example Oxynex® LM) or butylhydroxytoluene (BHT), L-(+)-ascorbyl palmitate and citric acid (for example Oxynex® 2004). Anti-oxidants of this type are usually employed in such compositions with compounds according to the invention in ratios in the range from 1000:1 to 1:1000, preferably in amounts of 100:1 to 1:100. The compositions according to the invention may comprise vitamins as further ingredients. The cosmetic compositions according to the invention preferably comprise vitamins and vitamin derivatives selected from vitamin A, vitamin A propionate, vitamin A palmitate, vitamin A acetate, retinol, vitamin B, thiamine chloride hydrochloride (vitamin B1), riboflavin (vitamin B2), nicotinamide, vitamin C (ascorbic acid), vitamin D, ergocalciferol (vitamin D2), vitamin E, DL-α-tocopherol, tocopherol E acetate, tocopherol hydrogensuccinate, vitamin K1, esculin (vitamin P active ingredient), thiamine (vitamin B1), nicotinic acid (niacin), pyridoxine, pyridoxal, pyridoxamine (vitamin B6), pantothenic acid, biotin, folic acid and cobalamine (vitamin B12), particularly preferably vitamin A palmitate, retinol, vitamin C and derivatives thereof, DL-α-tocopherol, tocopherol E acetate, nicotinic acid, pantothenic acid and biotin. Vitamins are usually employed here with compounds according to the invention in ratios in the range from 1000:1 to 1:1000, preferably in amounts of 100:1 to 1:100. It has been found here that antioxidants, such as, for example, beta-carotene and tocopherol, can accelerate the conversion of the compounds according to the invention into UV-filtering compounds. The present application therefore furthermore relates to the use of antioxidants for activating the compounds according to the invention. Compounds preferably to be employed in accordance with the invention have—after irradiation—a UV absorption in the UV-A and/or UV-B region. The compounds to be employed in accordance with the invention include precursors of broadband UV filters, which can be employed alone or in combination with further UV filters. Other compounds according to the invention which are likewise preferred are precursors of UV filters having an absorption maximum in the boundary region between UV-B and UV-A radiation. As UV-A II filters, they can therefore advantageously supplement the absorption spectrum of commercially available UV-B and UV-A I filters. Furthermore, preferred compounds have advantages on incorporation into the compositions: straight-chain or branched C1- to C20-alkoxy groups, in particular the long-chain alkoxy functions, such as ethylhexyloxy groups, increase the oil solubility of the compounds, in some cases, compounds of this type are in the form of oil components and can easily be incorporated into the composition or can function as solvent for other formulation constituents. In likewise preferred embodiments of the invention, however, the compositions according to the invention may also comprise compounds according to the invention which have low solubility or are insoluble in the composition matrix. In this case, the compounds are preferably dispersed in the cosmetic composition in finely divided form. Compositions which are particularly preferred in accordance with the invention can also serve as sunscreens and then also comprise UV filters in addition to the compounds according to the invention. On use of the dibenzoylmethane derivatives, which are particularly preferred as UV-A filters, but are also used as UV-B filters, or the cinnamic acid derivatives, which are employed, in particular, as UV-B filters, in combination with the compounds according to the invention, an additional advantage arises: the UV-sensitive dibenzoylmethane derivatives and cinnamic acid derivatives are additionally stabilised by the presence of the compounds according to the invention. The present invention therefore furthermore relates to the use of the compounds according to the invention for the stabilisation of dibenzoylmethane derivatives and/or cinnamic acid derivatives in compositions. In principle, all UV filters are suitable for combination with the compounds according to the invention. Particular preference is given to UV filters whose physiological acceptability has already been demonstrated. Both for UV-A and UV-B filters, there are many proven substances known from the specialist literature, for example benzylidenecamphor derivatives, such as 3-(4′-methylbenzylidene)-dl-camphor (for example Eusolex® 6300), 3-benzylidenecamphor (for example Mexoryl® SD), polymers of N-{(2 and 4)-[(2-oxoborn-3-ylidene)methyl]-benzyl}acrylamide (for example Mexoryl® SW), N,N,N-trimethyl-4-(2-oxoborn-3-ylidenemethyl)anilinium methylsulfate (for example Mexoryl® SK) or (2-oxoborn-3-ylidene)toluene-4-sulfonic acid (for example Mexoryl® SL), benzoyl- or dibenzoylmethanes, such as 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione (for example Eusolex® 9020) or 4-isopropyldibenzoylmethane (for example Eusolex® 8020), benzophenones, such as 2-hydroxy-4-methoxybenzophenone (for example Eusolex® 4360) or 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid and its sodium salt (for example Uvinul® MS-40), methoxycinnamic acid esters, such as octyl methoxycinnamate (for example Eusolex® 2292), isopentyl 4-methoxycinnamate, for example as a mixture of the isomers (for example Neo Heliopan® E 1000), salicylate derivatives, such as 2-ethylhexyl salicylate (for example Eusolex® OS), 4-isopropylbenzyl salicylate (for example Megasol®) or 3,3,5-trimethylcyclohexyl salicylate (for example Eusolex® HMS), 4-aminobenzoic acid and derivatives, such as 4-aminobenzoic acid, 2-ethylhexyl 4-(dimethylamino)benzoate (for example Eusolex® 6007), ethoxylated ethyl 4-aminobenzoate (for example Uvinul® P25), phenylbenzimidazolesulfonic acids, such as 2-phenylbenzimidazole-5-sulfonic acid and potassium, sodium and triethanolamine salts thereof (for example Eusolex® 232), 2,2-(1,4-phenylene)bisbenzimidazole-4,6-disulfonic acid and salts thereof (for example Neoheliopan® AP) or 2,2-(1,4-phenylene)bisbenzimidazole-6-sulfonic acid; and further substances, such as 2-ethylhexyl 2-cyano-3,3-diphenylacrylate (for example Eusolex® OCR), 3,3′-(1,4-phenylenedimethylene)bis(7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1-ylmethanesulfonic acid and salts thereof (for example Mexoryl® SX) and 2,4,6-trianilino-(p-carbo-2′-ethylhexyl-1′-oxy)-1,3,5-triazine (for example Uvinul® T 150) hexyl 2-(4-diethylamino-2-hydroxybenzoyl)benzoate (for example Uvinul®UVA Plus, BASF). The compounds mentioned in the list should only be regarded as examples. It is of course also possible to use other UV filters. These organic UV filters are generally incorporated into cosmetic formulations in an amount of 0.5 to 10 percent by weight, preferably 1-8%. Further suitable organic UV filters are, for example, 2-(2H-benzotriazol-2-yl)-4-methyl-6-(2-methyl-3-(1,3,3,3-tetramethyl-1-(trimethylsilyloxy)disiloxanyl)propyl)phenol (for example Silatrizole®), 2-ethylhexyl 4,4′-[(6-[4-((1,1-dimethylethyl)aminocarbonyl)phenylamino]-1,3,5-triazine-2,4-diyl)diimino]bis(benzoate) (for example Uvasorb®HEB), α-(trimethylsilyl)-ω-[trimethylsilyl)oxy]poly[oxy(dimethyl [and approximately 6% of methyl[2-[p-[2,2-bis(ethoxycarbonyl]vinyl]phenoxy]-1-methyleneethyl] and approximately 1.5% of methyl[3-[p-[2,2-bis(ethoxycarbonyl)vinyl)phenoxy)propenyl) and 0.1 to 0.4% of (methylhydrogen]-silylene]] (n≈60) (CAS No. 207 574-74-1) 2,2′-methylenebis(6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)-phenol) (CAS No. 103 597-45-1) 2,2′-(1,4-phenylene)bis(1H-benzimidazole-4,6-disulfonic acid, monosodium salt) (CAS No. 180 898-37-7) and 2,4-bis{[4-(2-ethylhexyloxy)-2-hydroxy]phenyl}-6-(4-methoxyphenyl)-1,3,5-triazine (CAS No. 103 597-45-, 187 393-00-6). 2-ethylhexyl 4,4′-[(6-[4-((1,1-dimethylethyl)aminocarbonyl)phenylamino]-1,3,5-triazine-2,4-diyl)diimino]bis(benzoate) (for example Uvasorb® HEB), Further suitable UV filters are also methoxyflavones corresponding to the earlier German patent application DE-A-1 0232595. Organic UV filters are generally incorporated into cosmetic formulations in an amount of 0.5 to 20 percent by weight, preferably 1-15%. Conceivable inorganic UV filters are those from the group of the titanium dioxides, such as, for example, coated titanium dioxide (for example Eusolex® T-2000, Eusolex® T-AQUA, Eusolex® T-AVO), zinc oxides (for example Sachtotec®), iron oxides or also cerium oxides. These inorganic UV filters are generally incorporated into cosmetic compositions in an amount of 0.5 to 20 percent by weight, preferably 2-10%. Preferred compounds having UV-filtering properties are 3-(4′-methylbenzylidene)-dl-camphor, 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione, 4-isopropyldibenzoylmethane, 2-hydroxy-4-methoxybenzophenone, octyl methoxycinnamate, 3,3,5-trimethylcyclohexyl salicylate, 2-ethylhexyl 4-(dimethylamino)benzoate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, 2-phenylbenzimidazole-5-sulfonic acid and the potassium, sodium and triethanolamine salts thereof. Combination of one or more compounds according to the invention with further UV filters enables the protective action against damaging effects of UV radiation to be optimised. Optimised compositions may comprise, for example, the combination of the organic UV filters 4′-methoxy-6-hydroxyflavone with 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)propane-1,3-dione and 3-(4′-methylbenzylidene)-dl-camphor. This combination gives rise to broad-band protection, which can be supplemented by the addition of inorganic UV filters, such as titanium dioxide microparticles. All the said UV filters and the compounds according to the invention can also be employed in encapsulated form. In particular, it is advantageous to employ organic UV filters in encapsulated form. In detail, the following advantages arise: The hydrophilicity of the capsule wall can be set independently of the solubility of the UV filter or the compound of the formula I. Thus, for example, it is also possible to incorporate hydrophobic UV filters or compounds according to the invention into purely aqueous compositions. In addition, the oily impression on application of the composition comprising hydrophobic UV filters, which is frequently regarded as unpleasant, is suppressed. Certain UV filters, in particular dibenzoylmethane derivatives, exhibit only reduced photostability in cosmetic compositions. Encapsulation of these filters or compounds which impair the photostability of these filters, such as, for example, cinnamic acid derivatives, enables the photostability of the entire composition to be increased. Skin penetration by organic UV filters and the associated potential for irritation on direct application to the human skin is repeatedly being discussed in the literature. The encapsulation of the corresponding sub-stances which is proposed here suppresses this effect. In general, encapsulation of individual UV filters or compounds according to the invention or other ingredients enables composition problems caused by the interaction of individual composition constituents with one another, such as crystallisation processes, precipitation and agglomerate formation, to be avoided since the interaction is suppressed. It is therefore preferred in accordance with the invention for one or more of the above-mentioned UV filters or compounds according to the invention to be in encapsulated form. It is advantageous here for the capsules to be so small that they cannot be viewed with the naked eye. In order to achieve the above-mentioned effects, it is furthermore necessary for the capsules to be sufficiently stable and the encapsulated active ingredient (UV filter) only to be released to the environment to a small extent, or not at all. Suitable capsules can have walls of inorganic or organic polymers. For example, U.S. Pat. No. 6,242,099 B1 describes the production of suitable capsules with walls of chitin, chitin derivatives or polyhydroxylated polyamines. Capsules which can particularly preferably be employed in accordance with the invention have walls which can be obtained by a sol-gel process, as described in the applications WO 00/09652, WO 00/72806 and WO 00/71084. Preference is again given here to capsules whose walls are built up from silica gel (silica; undefined silicon oxide hydroxide). The production of corresponding capsules is known to the person skilled in the art, for example from the cited patent applications, whose contents expressly also belong to the subject-matter of the present application. The capsules in compositions according to the invention are preferably present in amounts which ensure that the encapsulated UV filters are pre-sent in the composition in the above-indicated amounts. The compositions according to the invention may in addition comprise further conventional skin-protecting or skin-care active ingredients. These may in principle be any active ingredients known to the person skilled in the art. Particularly preferred active ingredients are pyrimidinecarboxylic acids and/or aryl oximes. Pyrimidinecarboxylic acids occur in halophilic microorganisms and play a role in osmoregulation of these organisms (E. A. Galinski et al., Eur. J. Biochem., 149 (1985) pages 135-139). Of the pyrimidinecarboxylic acids, particular mention should be made here of ectoin ((S)-1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) and hydroxyectoin ((S,S)-1,4,5,6-tetrahydro-5-hydroxy-2-methyl-4-pyrimidinecarboxylic acid and derivatives thereof. These compounds stabilise enzymes and other biomolecules in aqueous solutions and organic solvents. Furthermore, they stabilise, in particular, enzymes against denaturing conditions, such as salts, extreme pH values, surfactants, urea, guanidinium chloride and other compounds. Ectoin and ectoin derivatives, such as hydroxyectoin, can advantageously be used in medicaments. In particular, hydroxyectoin can be employed for the preparation of a medicament for the treatment of skin diseases. Other areas of application of hydroxyectoin and other ectoin derivatives are typically in areas in which, for example, trehalose is used as additive. Thus, ectoin derivatives, such as hydroxyectoin, can be used as protectant in dried yeast and bacterial cells. Pharmaceutical products, such as non-glycosylated, pharmaceutically active peptides and proteins, for example t-PA, can also be protected with ectoin or its derivatives. Of the cosmetic applications, particular mention should be made of the use of ectoin and ectoin derivatives for the care of aged, dry or irritated skin. Thus, European patent application EP-A-0 671 161 describes, in particular, that ectoin and hydroxyectoin are employed in cosmetic compositions, such as powders, soaps, surfactant-containing cleansing products, lipsticks, rouge, make-up, care creams and sunscreen preparations. Preference is given here to the use of a pyrimidinecarboxylic acid of the following formula in which R1 is a radical H or C1-8-alkyl, R2 is a radical H or C1-4-alkyl, and R3, R4, R5 and R6 are each, independently of one another, a radical from the group H, OH, NH2 and C1-4-alkyl. Preference is given to the use of pyrimidinecarboxylic acids in which R2 is a methyl or ethyl group, and R1 or R5 and R6 are H. Particular preference is given to the use of the pyrimidinecarboxylic acids ectoin ((S)-1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) and hydroxyectoin ((S,S)-1,4,5,6-tetrahydro-5-hydroxy-2-methyl-4-pyrimidinecarboxylic acid). The compositions according to the invention preferably comprise pyrimidinecarboxylic acids of this type in amounts of up to 15% by weight. The pyrimidinecarboxylic acids are preferably employed here in ratios of 100:1 to 1:100 with respect to the compounds according to the invention, with ratios in the range 1:10 to 10:1 being particularly preferred. Of the aryl oximes, preference is given to the use of 2-hydroxy-5-methyllaurophenone oxime, which is also known as HMLO, LPO or F5. Its suitability for use in cosmetic compositions is disclosed, for example, in DE-A-41 16 123. Compositions which comprise 2-hydroxy-5-methyllaurophenone oxime are accordingly suitable for the treatment of skin diseases which are accompanied by inflammation. It is known that compositions of this type can be used, for example, for the therapy of psoriasis, various forms of eczema, irritative and toxic dermatitis, UV dermatitis and further allergic and/or inflammatory diseases of the skin and skin appendages. Compositions according to the invention which, in addition to the compound of the formula I, additionally comprise an aryl oxime, preferably 2-hydroxy-5-methyllaurophenone oxime, exhibit surprising antiinflammatory suitability. The compositions here preferably comprise 0.01 to 10% by weight of the aryl oxime, it being particularly preferred for the composition to comprise 0.05 to 5% by weight of aryl oxime. In a further, likewise preferred embodiment of the present invention, the composition according to the invention comprises at least one self-tanning agent. Advantageous self-tanning agents which can be employed are, inter alia, trioses and tetroses, such as, for example, the following compounds: Mention should also be made of 5-hydroxy-1,4-naphthoquinone (juglone), which can be extracted from the shells of fresh walnuts, and 2-hydroxy-1,4-naphthoquinone (lawsone), which occurs in henna leaves. The flavonoid diosmetin and its glycosides or sulfates can also be employed. These compounds can be employed here in the form of pure substances or plant extracts. Diosmetin can preferably be employed, for example, in the form of a chrysanthemum extract. Very particular preference is given to 1,3-dihydroxyacetone (DHA), a tri-functional sugar which occurs in the human body, and derivatives thereof. The said self-tanning agents can be employed alone or as a mixture. It is particularly preferred here for DHA to be employed in a mixture with a further self-tanning agent of those mentioned above. It has been found that the combination of self-tanning agents with the compounds according to the invention results in accelerated tanning compared with the use of the self-tanning agents alone. The present invention therefore furthermore relates to the corresponding use of the compounds according to the invention for accelerating the tanning action of self-tanning agents. All compounds or components which can be used in the compositions are either known and commercially available or can be synthesised by known processes. The one or more compounds according to the invention can be incorporated into cosmetic or dermatological compositions in the customary manner. Suitable compositions are those for external use, for example in the form of a cream, lotion, gel or as a solution which can be sprayed onto the skin. Suitable for internal use are administration forms such as capsules, coated tablets, powders, tablet solutions or solutions. Examples which may be mentioned of application forms of the compositions according to the invention are: solutions, suspensions, emulsions, PIT emulsions, pastes, ointments, gels, creams, lotions, powders, soaps, surfactant-containing cleansing preparations, oils, aerosols and sprays. Examples of other application forms are sticks, shampoos and shower compositions. Any desired customary vehicles, auxiliaries and, if desired, further active ingredients may be added to the composition. Preferred auxiliaries originate from the group of the preservatives, antioxidants, stabilisers, solubilisers, vitamins, colorants, odour improvers. Ointments, pastes, creams and gels may comprise the customary vehicles, for example animal and vegetable fats, waxes, paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, silica, talc and zinc oxide, or mixtures of these substances. Powders and sprays may comprise the customary vehicles, for example lactose, talc, silica, aluminium hydroxide, calcium silicate and polyamide powder, or mixtures of these substances. Sprays may additionally comprise the customary propellants, for example chlorofluorocarbons, propane/butane or dimethyl ether. Solutions and emulsions may comprise the customary vehicles, such as solvents, solubilisers and emulsifiers, for example water, ethanol, isopropanol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butyl glycol, oils, in particular cottonseed oil, peanut oil, wheatgerm oil, olive oil, castor oil and sesame oil, glycerol fatty acid esters, polyethylene glycols and fatty acid esters of sorbitan, or mixtures of these substances. Suspensions may comprise the customary vehicles, such as liquid diluents, for example water, ethanol or propylene glycol, suspension media, for example ethoxylated isostearyl alcohols, polyoxyethylene sorbitol esters and polyoxyethylene sorbitan esters, microcrystalline cellulose, aluminium metahydroxide, bentonite, agar-agar and tragacanth, or mixtures of these substances. Soaps may comprise the customary vehicles, such as alkali metal salts of fatty acids, salts of fatty acid monoesters, fatty acid protein hydrolysates, isothionates, lanolin, fatty alcohol, vegetable oils, plant extracts, glycerol, sugars, or mixtures of these substances. Surfactant-containing cleansing products may comprise the customary vehicles, such as salts of fatty alcohol sulfates, fatty alcohol ether sulfates, sulfosuccinic acid monoesters, fatty acid protein hydrolysates, isothionates, imidazolinium derivatives, methyl taurates, sarcosinates, fatty acid amide ether sulfates, alkylamidobetaines, fatty alcohols, fatty acid glycerides, fatty acid diethanolamides, vegetable and synthetic oils, lanolin derivatives, ethoxylated glycerol fatty acid esters, or mixtures of these substances. Face and body oils may comprise the customary vehicles, such as synthetic oils, such as fatty acid esters, fatty alcohols, silicone oils, natural oils, such as vegetable oils and oily plant extracts, paraffin oils, lanolin oils, or mixtures of these substances. Further typical cosmetic application forms are also lipsticks, lip-care sticks, mascara, eyeliner, eye shadow, rouge, powder make-up, emulsion make-up and wax make-up, and sunscreen, pre-sun and after-sun preparations. The preferred composition forms according to the invention include, in particular, emulsions. Emulsions according to the invention are advantageous and comprise, for example, the said fats, oils, waxes and other fatty substances, as well as water and an emulsifier, as usually used for a composition of this type. The lipid phase may advantageously be selected from the following group of substances: mineral oils, mineral waxes; oils, such as triglycerides of capric or caprylic acid, furthermore natural oils, such as, for example, castor oil; fats, waxes and other natural and synthetic fatty substances, preferably esters of fatty acids with alcohols having a low carbon number, for example with isopropanol, propylene glycol or glycerol, or esters of fatty alcohols with alkanoic acids having a low carbon number or with fatty acids; silicone oils, such as dimethylpolysiloxanes, diethylpolysiloxanes, diphenylpolysiloxanes and mixed forms thereof. For the purposes of the present invention, the oil phase of the emulsions, oleogels or hydrodispersions or lipodispersions is advantageously selected from the group of the esters of saturated and/or unsaturated, branched and/or unbranched alkanecarboxylic acids having a chain length of 3 to 30 C atoms and saturated and/or unsaturated, branched and/or unbranched alcohols having a chain length of 3 to 30 C atoms, or from the group of the esters of aromatic carboxylic acids and saturated and/or unsaturated, branched and/or unbranched alcohols having a chain length of 3 to 30 C atoms. Ester oils of this type can then advantageously be selected from the group isopropyl myristate, isopropyl palmitate, isopropyl stearate, isopropyl oleate, n-butyl stearate, n-hexyl laurate, n-decyl oleate, isooctyl stearate, isononyl stearate, isononyl isononanoate, 2-ethylhexyl palmitate, 2-ethylhexyl laurate, 2-hexyldecyl stearate, 2-octyldodecyl palmitate, oleyl oleate, oleyl erucate, erucyl oleate, erucyl erucate and synthetic, semi-synthetic and natural mixtures of esters of this type, for example jojoba oil. The oil phase may furthermore advantageously be selected from the group of the branched and unbranched hydrocarbons and waxes, silicone oils, dialkyl ethers, the group of the saturated or unsaturated, branched or unbranched alcohols, and fatty acid triglycerides, specifically the triglycerol esters of saturated and/or unsaturated, branched and/or unbranched alkanecarboxylic acids having a chain length of 8 to 24, in particular 12-18, C atoms. The fatty acid triglycerides may advantageously be selected, for example, from the group of the synthetic, semi-synthetic and natural oils, for example olive oil, sunflower oil, soya oil, peanut oil, rapeseed oil, almond oil, palm oil, coconut oil, palm kernel oil and the like. Any desired mixtures of oil and wax components of this type may also advantageously be employed for the purposes of the present invention. It may also be advantageous to employ waxes, for example cetyl palmitate, as the only lipid component of the oil phase. The oil phase is advantageously selected from the group 2-ethylhexyl isostearate, octyldodecanol, isotridecyl isononanoate, isoeicosane, 2-ethylhexyl cocoate, C12-15-alkyl benzoate, caprylic/capric acid triglyceride and dicapryl ether. Particularly advantageous are mixtures of C12-15-alkyl benzoate and 2-ethylhexyl isostearate, mixtures of C12-15-alkyl benzoate and isotridecyl isononanoate, as well as mixtures of C12-15-alkyl benzoate, 2-ethylhexyl isostearate and isotridecyl isononanoate. Of the hydrocarbons, paraffin oil, squalane and squalene may advantageously be used for the purposes of the present invention. Furthermore, the oil phase may also advantageously have a content of cyclic or linear silicone oils or consist entirely of oils of this type, although it is preferred to use an additional content of other oil-phase components in addition to the silicone oil or the silicone oils. The silicone oil to be used in accordance with the invention is advantageously cyclomethicone (octamethylcyclotetrasiloxane). However, it is also advantageous for the purposes of the present invention to use other silicone oils, for example hexamethylcyclotrisiloxane, polydimethylsiloxane or poly(methylphenylsiloxane). Also particularly advantageous are mixtures of cyclomethicone and isotridecyl isononanoate, of cyclomethicone and 2-ethylhexyl isostearate. The aqueous phase of the compositions according to the invention optionally advantageously comprises alcohols, diols or polyols having a low carbon number, and ethers thereof, preferably ethanol, isopropanol, propylene glycol, glycerol, ethylene glycol, ethylene glycol monoethyl or monobutyl ether, propylene glycol monomethyl, monoethyl or monobutyl ether, diethylene glycol monomethyl or monoethyl ether and analogous products, furthermore alcohols having a low carbon number, for example ethanol, isopropanol, 1,2-propanediol, glycerol, and, in particular, one or more thickeners, which may advantageously be selected from the group silicon dioxide, aluminium silicates, polysaccharides and derivatives thereof, for example hyaluronic acid, xanthan gum, hydroxypropylmethylcellulose, particularly advantageously from the group of the polyacrylates, preferably a polyacrylate from the group of the so-called Carbopols, for example Carbopol grades 980, 981, 1382, 2984 or 5984, in each case individually or in combination. In particular, mixtures of the above-mentioned solvents are used. In the case of alcoholic solvents, water may be a further constituent. Emulsions according to the invention are advantageous and comprise, for example, the said fats, oils, waxes and other fatty substances, as well as water and an emulsifier, as usually used for a formulation of this type. In a preferred embodiment, the compositions according to the invention comprise hydrophilic surfactants. The hydrophilic surfactants are preferably selected from the group of the alkylglucosides, acyl lactylates, betaines and coconut amphoacetates. The alkylglucosides are themselves advantageously selected from the group of the alkylglucosides which are distinguished by the structural formula where R represents a branched or unbranched alkyl radical having 4 to 24 carbon atoms, and where DP denotes a mean degree of glucosylation of up to 2. The value DP represents the degree of glucosidation of the alkylglucosides used in accordance with the invention and is defined as DP _ = p 1 100 · 1 + p 2 100 · 2 + p 3 100 · 3 + … = ∑ p i 100 · i in which p1, p2, p3 . . . pi represent the proportion of mono-, di-, tri- . . . i-fold glucosylated products in percent by weight. Advantageous in accordance with the invention is the selection of products having degrees of glucosylation of 1-2, particularly advantageously of 1.1 to 1.5, very particularly advantageously of 1.2-1.4, in particular of 1.3. The value DP takes into account the fact that alkylglucosides are generally, as a consequence of their preparation, in the form of mixtures of mono- and oligoglucosides. A relatively high content of monoglucosides, typically in the order of 40-70% by weight, is advantageous in accordance with the invention. Alkylglycosides which are particularly advantageously used in accordance with the invention are selected from the group octyl glucopyranoside, nonyl glucopyranoside, decyl glucopyranoside, undecyl glucopyranoside, dodecyl glucopyranoside, tetradecyl glucopyranoside and hexadecyl glucopyranoside. It is likewise advantageous to employ natural or synthetic raw materials and auxiliaries or mixtures which are distinguished by an effective content of the active ingredients used in accordance with the invention, for example Plantaren® 1200 (Henkel KGaA), Oramix® NS 10 (Seppic). The acyllactylates are themselves advantageously selected from the group of the substances which are distinguished by the structural formula where R1 denotes a branched or unbranched alkyl radical having 1 to 30 carbon atoms, and M+ is selected from the group of the alkali metal ions and the group of ammonium ions which are substituted by one or more alkyl and/or one or more hydroxyalkyl radicals, or corresponds to half an equivalent of an alkaline earth metal ion. For example, sodium isostearyl lactylate, for example the product Pathionic® ISL from the American Ingredients Company, is advantageous. The betaines are advantageously selected from the group of the sub-stances which are distinguished by the structural formula where R2 denotes a branched or unbranched alkyl radical having 1 to 30 carbon atoms. R2 particularly advantageously denotes a branched or unbranched alkyl radical having 6 to 12 carbon atoms. For example, capramidopropylbetaine, for example the product Tego® Betain 810 from Th. Goldschmidt AG, is advantageous. A coconut amphoacetate which is advantageous in accordance with the invention is, for example, sodium coconut amphoacetate, as available under the name Miranol® Ultra C32 from Miranol Chemical Corp. The compositions according to the invention are advantageously characterised in that the hydrophilic surfactant(s) is (are) present in concentrations of 0.01-20% by weight, preferably 0.05-10% by weight, particularly preferably 0.1-5% by weight, in each case based on the total weight of the composition. For use, the cosmetic and dermatological compositions according to the invention are applied to the skin and/or the hair in an adequate amount in the usual manner for cosmetics. Cosmetic and dermatological compositions according to the invention may exist in various forms. Thus, they may be, for example, a solution, a water-free composition, an emulsion or microemulsion of the water-in-oil (W/O) type or of the oil-in-water (O/W) type, a multiple emulsion, for example of the water-in-oil-in-water (W/O/W) type, a gel, a solid stick, an ointment or an aerosol. It is also advantageous to administer active ingredients in encapsulated form, for example in collagen matrices and other conventional encapsulation materials, for example as cellulose encapsulations, in gelatine, wax matrices or liposomally encapsulated. In particular, wax matrices, as described in DE-A 43 08 282, have proven favourable. Preference is given to emulsions. O/W emulsions are particularly preferred. Emulsions, W/O emulsions and O/W emulsions are obtainable in a conventional manner. Emulsifiers that can be used are, for example, the known W/O and O/W emulsifiers. It is advantageous to use further conventional co-emulsifiers in the preferred O/W emulsions according to the invention. Co-emulsifiers which are advantageous in accordance with the invention are, for example, O/W emulsifiers, principally from the group of the sub-stances having HLB values of 11-16, very particularly advantageously having HLB values of 14.5-15.5, so long as the O/W emulsifiers have saturated radicals R and R′. If the O/W emulsifiers have unsaturated radicals R and/or R′ or in the case of isoalkyl derivatives, the preferred HLB value of such emulsifiers may also be lower or higher. It is advantageous to select the fatty alcohol ethoxylates from the group of ethoxylated stearyl alcohols, cetyl alcohols, cetylstearyl alcohols (cetearyl alcohols). Particular preference is given to the following: polyethylene glycol (13) stearyl ether (steareth-13), polyethylene glycol (14) stearyl ether (steareth-14), polyethylene glycol (15) stearyl ether (steareth-15), polyethylene glycol (16) stearyl ether (steareth-16), polyethylene glycol (17) stearyl ether (steareth-17), polyethylene glycol (18) stearyl ether (steareth-18), polyethylene glycol (19) stearyl ether (steareth-19), polyethylene glycol (20) stearyl ether (steareth-20), polyethylene glycol (12) isostearyl ether (isosteareth-12), polyethylene glycol (13) isostearyl ether (isosteareth-13), polyethylene glycol (14) isostearyl ether (isosteareth-14), polyethylene glycol (15) isostearyl ether (isosteareth-15), polyethylene glycol (16) isostearyl ether (isosteareth-16), polyethylene glycol (17) isostearyl ether (isosteareth-17), polyethylene glycol (18) isostearyl ether (isosteareth-18), polyethylene glycol (19) isostearyl ether (isosteareth-19), polyethylene glycol (20) isostearyl ether (isosteareth-20), polyethylene glycol (13) cetyl ether (ceteth-13), polyethylene glycol (14) cetyl ether (ceteth-14), polyethylene glycol (15) cetyl ether (ceteth-15), polyethylene glycol (16) cetyl ether (ceteth-16), polyethylene glycol (17) cetyl ether (ceteth-17), polyethylene glycol (18) cetyl ether (ceteth-18), polyethylene glycol (19) cetyl ether (ceteth-19), polyethylene glycol (20) cetyl ether (ceteth-20), polyethylene glycol (13) isocetyl ether (isoceteth-13), polyethylene glycol (14) isocetyl ether (isoceteth-14), polyethylene glycol (15) isocetyl ether (isoceteth-15), polyethylene glycol (16) isocetyl ether (isoceteth-16), polyethylene glycol (17) isocetyl ether (isoceteth-17), polyethylene glycol (18) isocetyl ether (isoceteth-18), polyethylene glycol (19) isocetyl ether (isoceteth-19), polyethylene glycol (20) isocetyl ether (isoceteth-20), polyethylene glycol (12) oleyl ether (oleth-12), polyethylene glycol (13) oleyl ether (oleth-13), polyethylene glycol (14) oleyl ether (oleth-14), polyethylene glycol (15) oleyl ether (oleth-15), polyethylene glycol (12) lauryl ether (laureth-12), polyethylene glycol (12) isolauryl ether (isolaureth-12), polyethylene glycol (13) cetylstearyl ether (ceteareth-13), polyethylene glycol (14) cetylstearyl ether (ceteareth-14), polyethylene glycol (15) cetylstearyl ether (ceteareth-15), polyethylene glycol (16) cetylstearyl ether (ceteareth-16), polyethylene glycol (17) cetylstearyl ether (ceteareth-17), polyethylene glycol (18) cetylstearyl ether (ceteareth-18), polyethylene glycol (19) cetylstearyl ether (ceteareth-19), polyethylene glycol (20) cetylstearyl ether (ceteareth-20). It is furthermore advantageous to select the fatty acid ethoxylates from the following group: polyethylene glycol (20) stearate, polyethylene glycol (21) stearate, polyethylene glycol (22) stearate, polyethylene glycol (23) stearate, polyethylene glycol (24) stearate, polyethylene glycol (25) stearate, polyethylene glycol (12) isostearate, polyethylene glycol (13) isostearate, polyethylene glycol (14) isostearate, polyethylene glycol (15) isostearate, polyethylene glycol (16) isostearate, polyethylene glycol (17) isostearate, polyethylene glycol (18) isostearate, polyethylene glycol (19) isostearate, polyethylene glycol (20) isostearate, polyethylene glycol (21) isostearate, polyethylene glycol (22) isostearate, polyethylene glycol (23) isostearate, polyethylene glycol (24) isostearate, polyethylene glycol (25) isostearate, polyethylene glycol (12) oleate, polyethylene glycol (13) oleate, polyethylene glycol (14) oleate, polyethylene glycol (15) oleate, polyethylene glycol (16) oleate, polyethylene glycol (17) oleate, polyethylene glycol (18) oleate, polyethylene glycol (19) oleate, polyethylene glycol (20) oleate, An ethoxylated alkyl ether carboxylic acid or salt thereof which can advantageously be used is sodium laureth-11 carboxylate. An alkyl ether sulfate which can advantageously be used is sodium laureth-14 sulfate. An ethoxylated cholesterol derivative which can advantageously be used is polyethylene glycol (30) cholesteryl ether. Polyethylene glycol (25) soyasterol has also proven successful. Ethoxylated triglycerides which can advantageously be used are the polyethylene glycol (60) evening primrose glycerides. It is furthermore advantageous to select the polyethylene glycol glycerol fatty acid esters from the group polyethylene glycol (20) glyceryl laurate, polyethylene glycol (21) glyceryl laurate, polyethylene glycol (22) glyceryl laurate, polyethylene glycol (23) glyceryl laurate, polyethylene glycol (6) glyceryl caprate/caprinate, polyethylene glycol (20) glyceryl oleate, polyethylene glycol (20) glyceryl isostearate, polyethylene glycol (18) glyceryl oleate/cocoate. It is likewise favourable to select the sorbitan esters from the group polyethylene glycol (20) sorbitan monolaurate, polyethylene glycol (20) sorbitan monostearate, polyethylene glycol (20) sorbitan monoisostearate, polyethylene glycol (20) sorbitan monopalmitate, polyethylene glycol (20) sorbitan monooleate. Optional W/O emulsifiers, but ones which may nevertheless be advantageously employed in accordance with the invention are the following: fatty alcohols having 8 to 30 carbon atoms, monoglycerol esters of saturated and/or unsaturated, branched and/or unbranched alkanecarboxylic acids having a chain length of 8 to 24, in particular 12-18 C atoms, diglycerol esters of saturated and/or unsaturated, branched and/or unbranched alkanecarboxylic acids having a chain length of 8 to 24, in particular 12-18 C atoms, monoglycerol ethers of saturated and/or unsaturated, branched and/or unbranched alcohols having a chain length of 8 to 24, in particular 12-18 C atoms, diglycerol ethers of saturated and/or unsaturated, branched and/or unbranched alcohols having a chain length of 8 to 24, in particular 12-18 C atoms, propylene glycol esters of saturated and/or unsaturated, branched and/or unbranched alkanecarboxylic acids having a chain length of 8 to 24, in particular 12-18 C atoms, and sorbitan esters of saturated and/or unsaturated, branched and/or unbranched alkanecarboxylic acids having a chain length of 8 to 24, in particular 12-18 C atoms. Particularly advantageous W/O emulsifiers are glyceryl monostearate, glyceryl monoisostearate, glyceryl monomyristate, glyceryl monooleate, diglyceryl monostearate, diglyceryl monoisostearate, propylene glycol monostearate, propylene glycol monoisostearate, propylene glycol monocaprylate, propylene glycol monolaurate, sorbitan monoisostearate, sorbitan monolaurate, sorbitan monocaprylate, sorbitan monoisooleate, sucrose distearate, cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, isobehenyl alcohol, selachyl alcohol, chimyl alcohol, polyethylene glycol (2) stearyl ether (steareth-2), glyceryl monolaurate, glyceryl monocaprinate, glyceryl monocaprylate. Preferred compositions in accordance with the invention are particularly suitable for protecting human skin against ageing processes and against oxidative stress, i.e. against damage caused by free radicals, as are generated, for example, by solar irradiation, heat or other influences. In this connection, they are in the various administration forms usually used for this application. For example, it may, in particular, be in the form of a lotion or emulsion, such as in the form of a cream or milk (O/W, W/O, O/W/O, W/O/W), in the form of oily-alcoholic, oily-aqueous or aqueous-alcoholic gels or solutions, in the form of solid sticks or may be formulated as an aerosol. The composition may comprise cosmetic adjuvants which are usually used in this type of composition, such as, for example, thickeners, softeners, moisturisers, surface-active agents, emulsifiers, preservatives, antifoams, perfumes, waxes, lanolin, propellants, dyes and/or pigments which colour the composition itself or the skin, and other ingredients usually used in cosmetics. The dispersant or solubiliser used can be an oil, wax or other fatty substance, a lower monoalcohol or lower polyol or mixtures thereof. Particularly preferred monoalcohols or polyols include ethanol, isopropanol, propylene glycol, glycerol and sorbitol. A preferred embodiment of the invention is an emulsion in the form of a protective cream or milk which, apart from the compound(s) according to the invention, comprises, for example, fatty alcohols, fatty acids, fatty acid esters, in particular triglycerides of fatty acids, lanolin, natural and synthetic oils or waxes and emulsifiers in the presence of water. Further preferred embodiments are oily lotions based on natural or synthetic oils and waxes, lanolin, fatty acid esters, in particular triglycerides of fatty acids, or oily-alcoholic lotions based on a lower alcohol, such as ethanol, or a glycerol, such as propylene glycol, and/or a polyol, such as glycerol, and oils, waxes and fatty acid esters, such as triglycerides of fatty acids. The composition according to the invention may also be in the form of an alcoholic gel which comprises one or more lower alcohols or polyols, such as ethanol, propylene glycol or glycerol, and a thickener, such as siliceous earth. The oily-alcoholic gels also comprise natural or synthetic oil or wax. The solid sticks consist of natural or synthetic waxes and oils, fatty alcohols, fatty acids, fatty acid esters, lanolin and other fatty substances. If a composition is formulated as an aerosol, the customary propellants, such as alkanes, fluoroalkanes and chlorofluoroalkanes, are generally used. The cosmetic composition may also be used to protect the hair against photochemical damage in order to prevent colour changes, bleaching or damage of a mechanical nature. In this case, a suitable formulation is in the form of a rinse-out shampoo, lotion, gel or emulsion, the composition in question being applied before or after shampooing, before or after colouring or bleaching or before or after permanent waving. It is also possible to select a composition in the form of a lotion or gel for styling and treating the hair, in the form of a lotion or gel for brushing or blow-waving, in the form of a hair lacquer, permanent waving composition, colorant or bleach for the hair. Besides the compound(s) according to the invention, the composition having light-protection properties may comprise various adjuvants used in this type of composition, such as surface-active agents, thickeners, polymers, softeners, preservatives, foam stabilisers, electrolytes, organic solvents, silicone derivatives, oils, waxes, antigrease agents, dyes and/or pigments which colour the composition itself or the hair, or other ingredients usually used for hair care. If the composition according to the invention is a hair-care composition, it is preferred for this composition to comprise at least one compound of the formula I in which R1 stands for a radical Ra or Rb where m stands for an integer from the range from 1 to 3, and A1-A3 each, independently of one another, stand for a radical —(CH2)o(O)pH, where o stands for 1, 2 or 3, and p stands for 0 or 1, where it is very particularly preferred for the at least one compound of the formula I to be a compound selected from compounds Iah and Ib to Iv, as described above. The present invention furthermore relates to a process for the preparation of a composition which is characterised in that at least one compound which itself does not exhibit significant UV absorption in the UV-A or UV-B region, but is reactive under application conditions and produces UV-A or UV-B protection, is mixed with a vehicle which is suitable cosmetically or dermatologically or for foods or for domestic products, and to the use of a compound of the formula I for the preparation of a composition having antioxidant properties. The compositions according to the invention can be prepared with the aid of techniques which are well known to the person skilled in the art. The mixing can result in dissolution, emulsification or dispersion of the compound according to the invention in the vehicle. In a process which is preferred in accordance with the invention, the compound of the formula I is prepared by hydrogenation of at least one compound of the formula I ena or I enb where the radicals Ar, X, Y, Z1 and Z2 and R1 correspond to those of the desired formula I. Molecular hydrogen, for example, is suitable for the hydrogenation. If molecular hydrogen is used for the hydrogenation of the compounds of the formula I ena or I enb, the hydrogenation is preferably carried out in the presence of a catalyst or catalyst system. Suitable catalysts for the hydrogenation are all common homogeneous and heterogeneous catalysts, particularly preferably at least one noble metal, preferably selected from the elements Pt, Pd and Rh, or a transition metal, such as Mo, W, Cr, but particularly Fe, Co and Ni, either individually or in a mixture. The catalyst(s) or catalyst mixture(s) here may also be employed on supports, such as carbon, activated carbon, aluminium oxide, barium carbonate, barium sulfate, calcium carbonate, strontium carbonate or kieselguhr. The metal here may also be employed in the form of the Raney compound, for example Raney nickel. If the catalysis is carried out in a homogeneous process, it is preferred for the catalyst employed to be one or more complex compounds of the said metals, such as, for example, Wilkinson's catalyst [chlorotris(triphenylphosphine)rhodium]. It is furthermore possible to employ salts of the said metals, which can be reduced in situ by a reducing agent and form a finely divided metal(0) species in situ. Suitable noble-metal salts are, for example, palladium acetate, palladium bromide and palladium chloride, suitable reducing agents are, for example, hydrogen, hydrazine, sodium borohydride and formates. In a preferred variant of the present invention, a heterogeneous catalyst is employed, it being particularly preferred for the catalyst employed in the process according to the invention to be Pd or Pt, preferably on activated-carbon support, for example 5% by weight of Pd or Pt on C. The hydrogenation is usually carried out at a temperature in the range from 20-150° C. The hydrogenation is furthermore advantageously carried out at a hydrogen pressure of 1 to 200 bar. Suitable solvents are protic solvents, in particular the usual protic solvents known to the person skilled in the art, such as water, lower alcohols, such as, for example, methanol, ethanol and isopropanol, and primary and secondary amines, and mixtures of protic solvents of this type, where it may be particularly preferred for the solvent employed to be water. Suitable solvents for this reaction are furthermore also conventional aprotic solvents. For example, diethyl ether, tetrahydrofuran, benzene, toluene, acetonitrile, dimethoxyethane, dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone can be employed. In a likewise preferred embodiment of the preparation process according to the invention, the hydrogenation is carried out in the solid state, i.e. no additional solvent is necessary. When the reaction is complete, the work-up can be carried out by conventional methods. For example, the catalyst can be filtered off, the filtrate freed from solvent, for example by heating at reduced pressure compared with atmospheric pressure, and the resultant product purified further by conventional methods. The further purification of the reaction products can likewise be carried out by conventional methods, for example by recrystallisation from a suitable solvent, or by chromatographic methods. It has also been noted that compounds according to the invention can have a stabilising effect on the composition. When used in corresponding products, the latter thus also remain stable for longer and do not change their pharmaceutical and sensory nature. In particular, the effectiveness of the ingredients, for example vitamins, is retained even in the case of application over extended periods or extended storage. This is, inter alia, particularly advantageous in the case of compositions for protecting the skin against the effect of UV rays since these cosmetics are exposed to particularly high stresses by UV radiation. The positive effects of compounds according to the invention give rise to their particular suitability for use in cosmetic or pharmaceutical compositions. The properties of compounds of the formula I should likewise be regarded as positive for use in foods or as food supplements or as functional foods. The further explanations given for foods also apply correspondingly to food supplements and functional foods. The foods which can be enriched with one or more compounds according to the invention in accordance with the present invention include all materials which are suitable for consumption by animals or consumption by humans, for example vitamins and provitamins thereof, fats, minerals or amino acids. (The foods may be solid, but also liquid, i.e. in the form of a beverage). The present invention accordingly furthermore relates to the use of a compound of the formula I as food additive for human or animal nutrition, and to compositions which are foods or food supplements and comprise corresponding vehicles. Foods which can be enriched with one or more compounds according to the invention in accordance with the present invention are, for example, also foods which originate from a single natural source, such as, for example, sugar, unsweetened juice, squash or puree of a single plant species, such as, for example, unsweetened apple juice (for example also a mixture of different types of apple juice), grapefruit juice, orange juice, apple compote, apricot squash, tomato juice, tomato sauce, tomato puree, etc. Further examples of foods which can be enriched with one or more compounds according to the invention in accordance with the present invention are corn or cereals from a single plant species and materials produced from plant species of this type, such as, for example, cereal syrup, rye flour, wheat flour or oat bran. Mixtures of foods of this type are also suitable for being enriched with one or more compounds according to the invention in accordance with the present invention, for example multivitamin preparations, mineral mixtures or sweetened juice. As further examples of foods which can be enriched with one or more compounds according to the invention in accordance with the present invention, mention may be made of food compositions, for example prepared cereals, biscuits, mixed drinks, foods prepared especially for children, such as yoghurt, diet foods, low-calorie foods or animal feeds. The foods which can be enriched with one or more compounds according to the invention in accordance with the present invention thus include all edible combinations of carbohydrates, lipids, proteins, inorganic elements, trace elements, vitamins, water or active metabolites of plants and animals. The foods which can be enriched with one or more compounds according to the invention in accordance with the present invention are preferably administered orally, for example in the form of meals, pills, tablets, capsules, powders, syrup, solutions or suspensions. The foods according to the invention enriched with one or more compounds according to the invention can be prepared with the aid of techniques which are well known to the person skilled in the art. Due to their action as antioxidants or free-radical scavengers, compounds according to the invention are also suitable as medicament ingredient, where they support or replace natural mechanisms which scavenge free radicals in the body. The compounds according to the invention can in some cases be compared in their action with free-radical scavengers, such as vitamin C. Compounds according to the invention can be used, for example, for the preventative treatment of inflammation and allergies of the skin and in certain cases for preventing certain types of cancer. Compounds according to the invention are particularly suitable for the preparation of a medicament for the treatment of inflammation, allergies and irritation, in particular of the skin. It is furthermore possible to prepare medicaments which act as vein tonic, as agent for increasing the strength of blood capillaries, as cuperose inhibitor, as inhibitor of chemical, physical or actinic erythemas, as agent for the treatment of sensitive skin, as decongestant, as dehydration agent, as slimming agent, as anti-wrinkle agent, as stimulators of the synthesis of components of the extracellular matrix, as strengthening agent for improving skin elasticity, and as anti-ageing agent. Furthermore, compounds according to the invention which are preferred in this connection exhibit anti-allergic and anti-inflammatory and anti-irritative actions. They are therefore suitable for the preparation of medicaments for the treatment of inflammation or allergic reactions. The invention is explained in greater detail below with reference to examples. The invention can be carried out throughout the scope claimed and is not restricted to the examples given here. EXAMPLES Example 1 Preparation of di-2-ethylhexyl 4-hydroxy-3,5-dimethoxy-benzylmalonate Di-2-ethylhexyl (4-hydroxy-3,5-dimethoxybenzylidene)malonate (the synthesis of this compound is described in WO-A-2003/007906, the disclosure content of which in this respect is expressly part of the subject-matter of the present application) is dissolved in methanol (14 ml/mmol), and 5% Pd/C (56% water; Merck: Art. No. 275175; 0.54 g/mmol) is added. The hydrogenation is subsequently carried out with hydrogen 3.0 at room temperature and atmospheric pressure. The catalyst is separated off by filtration. The filtrate is freed from solvent in vacuo, and the greenish oil remaining is taken up in tert-butyl methyl ether (MTBE) and extracted 2× with 1 N HCl, 1× with saturated, aqueous NaHCO3 solution and 1× with saturated, aqueous NaCl solution. The organic phase is dried over sodium sulfate, and the solvent is removed in vacuo. The purification is carried out by filtration through silica gel. To this end, the crude product is taken up in petroleum ether (PE) and eluted with PE/MTBE, giving analytically pure product as colourless oil. Example 2 Preparation of 2-ethylhexyl 2-cyano-3,3,-diphenyl-propionate 2-Ethylhexyl 2-cyano-3,3-diphenylacrylate (Eusolex® OCR; Merck) is dissolved in tetrahydrofuran (THF), and 5% Pd/C (56% water; Merck: Art. No. 275175) is added. The hydrogenation is subsequently carried out with hydrogen 3.0 at room temperature and atmospheric pressure. The catalyst is separated off by filtration. The filtrate is freed from solvent in vacuo, and the residue is washed. The organic phase is dried over sodium sulfate, and the solvent is removed in vacuo. The purification is carried out by filtration through silica gel, giving analytically pure product. In principle, all compounds of the formula I can be prepared analogously to Example 1 or 2. For example, the following compounds can be obtained from the respective corresponding benzylidene compounds: di-2-ethylhexyl 4-methoxybenzylmalonate, 2-ethylhexyl 4-methoxyphenylpropionate, 2-ethylhexyl 4-hydroxy-3,5-dimethoxyphenylpropionate, diethyl 4-hydroxy-3,5-dimethoxybenzylmalonate, 2-ethylhexyl 4-hydroxyphenylpropionate, di-2-ethylhexyl 4-hydroxybenzylmalonate, 2-ethylhexyl 3-hydroxyphenylpropionate, di-2-ethylhexyl 3-hydroxybenzylmalonate, 2-ethylhexyl 2-hydroxyphenylpropionate, di-2-ethylhexyl 2-hydroxybenzylmalonate, di-2-ethylhexyl 3,4,5-trimethoxybenzylmalonate, 2-ethylhexyl 3,4,5-trimethoxyphenylpropionate, di-2-ethylhexyl 2,4,5-trimethoxybenzylmalonate, 2-ethylhexyl 2,4,5-trimethoxyphenylpropionate, di-2-ethylhexyl 2,3,4-trimethoxybenzylmalonate, 2-ethylhexyl 2,3,4-trimethoxyphenylpropionate, di-2-ethylhexyl 2,3,5-trimethoxybenzylmalonate, 2-ethylhexyl 2,3,5-trimethoxyphenylpropionate, di-2-ethylhexyl 2,3,6-trimethoxybenzylmalonate, 2-ethylhexyl 2,3,6-trimethoxyphenylpropionate, di-2-ethylhexyl 2,4,6-trimethoxybenzylmalonate, 2-ethylhexyl 2,4,6-trimethoxyphenylpropionate, di-2-ethylhexyl 2,4-dimethoxybenzylmalonate, 2-ethylhexyl 2,4-dimethoxyphenylpropionate, di-2-ethylhexyl 2,3-dimethoxybenzylmalonate, 2-ethylhexyl 2,3-dimethoxyphenylpropionate, di-2-ethylhexyl 2,5-dimethoxybenzylmalonate, 2-ethylhexyl 2,5-dimethoxyphenylpropionate, di-2-ethylhexyl 3,4-dimethoxybenzylmalonate, 2-ethylhexyl 3,4-dimethoxyphenylpropionate, di-2-ethylhexyl 3,5-dimethoxybenzylmalonate, 2-ethylhexyl 3,5-dimethoxyphenylpropionate, 2-ethylhexyl 4-hydroxy-3-methoxyphenylpropionate, di-2-ethylhexyl 4-hydroxy-3-methoxybenzylmalonate, di-2-ethylhexyl 3,4,5-trihydroxybenzylmalonate, 2-ethylhexyl 3,4,5-trihydroxyphenylpropionate, di-2-ethylhexyl 2,4,5-trihydroxybenzylmalonate, 2-ethylhexyl 2,4,5-trihydroxyphenylpropionate, di-2-ethylhexyl 2,3,4-trihydroxybenzylmalonate, 2-ethylhexyl 2,3,4-trihydroxyphenylpropionate, di-2-ethylhexyl 2,4-dihydroxybenzylmalonate, 2-ethylhexyl 2,4-dihydroxyphenylpropionate, di-2-ethylhexyl 2,3-dihydroxybenzylmalonate, 2-ethylhexyl 2,3-dihydroxyphenylpropionate, di-2-ethylhexyl 2,5-dihydroxybenzylmalonate, 2-ethylhexyl 2,5-dihydroxyphenylpropionate, di-2-ethylhexyl 3,4-dihydroxybenzylmalonate, 2-ethylhexyl 3,4-dihydroxyphenylpropionate, di-2-ethylhexyl 3,5-dihydroxybenzylmalonate, 2-ethylhexyl 3,5-dihydroxyphenylpropionate, 2-ethylhexyl 3-hydroxy-4-methoxyphenylpropionate, di-2-ethylhexyl 3-hydroxy-4-methoxybenzylmalonate, 4-methoxybenzylmalonic acid, 4-methoxyphenylpropionic acid, 4-hydroxy-3,5-dimethoxyphenylpropionic acid, 4-hydroxyphenylpropionic acid, 4-hydroxybenzylmalonic acid, 3-hydroxyphenylpropionic acid, 3-hydroxybenzylmalonic acid, 2-hydroxyphenylpropionic acid, 2-hydroxybenzylmalonic acid, 3,4,5-trimethoxybenzylmalonic acid, 3,4,5-trimethoxyphenylpropionic acid, 2,4,5-trimethoxybenzylmalonic acid, 2,4,5-trimethoxyphenylpropionic acid, 2,3,4-trimethoxybenzylmalonic acid, 2,3,4-trimethoxyphenylpropionic acid, 2,3,5-trimethoxybenzylmalonic acid, 2,3,5-trimethoxyphenylpropionic acid, 2,3,6-trimethoxybenzylmalonic acid, 2,3,6-trimethoxyphenylpropionic acid, 2,4,6-trimethoxybenzylmalonic acid, 2,4,6-trimethoxyphenylpropionic acid, 2,4-dimethoxybenzylmalonic acid, 2,4-dimethoxyphenylpropionic acid, 2,3-dimethoxybenzylmalonic acid, 2,3-dimethoxyphenylpropionic acid, 2,5-dimethoxybenzylmalonic acid, 2,5-dimethoxyphenylpropionic acid, 3,4-dimethoxybenzylmalonic acid, 3,4-dimethoxyphenylpropionic acid, 3,5-dimethoxybenzylmalonic acid, 3,5-dimethoxyphenylpropionic acid, 4-hydroxy-3-methoxyphenylpropionic acid, 4-hydroxy-3-methoxybenzylmalonic acid, 3,4,5-trihydroxybenzylmalonic acid, 3,4,5-trihydroxyphenylpropionic acid, 2,4,5-trihydroxybenzylmalonic acid, 2,4,5-trihydroxyphenylpropionic acid, 2,3,4-trihydroxybenzylmalonic acid, 2,3,4-trihydroxyphenylpropionic acid, 2,4-dihydroxybenzylmalonic acid, 2,4-dihydroxyphenylpropionic acid, 2,3-dihydroxybenzylmalonic acid, 2,3-dihydroxyphenylpropionic acid, 2,5-dihydroxybenzylmalonic acid, 2,5-dihydroxyphenylpropionic acid, 3,4-dihydroxybenzylmalonic acid, 3,4-dihydroxyphenylpropionic acid, 3,5-dihydroxybenzylmalonic acid, 3,5-dihydroxyphenylpropionic acid, 3-hydroxy-4-methoxyphenylpropionic acid, 3-hydroxy-4-methoxybenzylmalonic acid, diethyl 4-methoxybenzylmalonate, ethyl 4-methoxyphenylpropionate, ethyl 4-hydroxy-3,5-dimethoxyphenylpropionate, diethyl 3,4,5-trimethoxybenzylmalonate, ethyl 3,4,5-trimethoxyphenylpropionate, diethyl 2,4,5-trimethoxybenzylmalonate, ethyl 2,4,5-trimethoxyphenylpropionate, diethyl 2,3,4-trimethoxybenzylmalonate, ethyl 2,3,4-trimethoxyphenylpropionate, diethyl 2,3,5-trimethoxybenzylmalonate, ethyl 2,3,5-trimethoxyphenylpropionate, diethyl 2,3,6-trimethoxybenzylmalonate, ethyl 2,3,6-trimethoxyphenylpropionate, diethyl 2,4,6-trimethoxybenzylmalonate, ethyl 2,4,6-trimethoxyphenylpropionate, diethyl 2,4-dimethoxybenzylmalonate, ethyl 2,4-dimethoxyphenylpropionate, diethyl 2,3-dimethoxybenzylmalonate, ethyl 2,3-dimethoxyphenylpropionate, diethyl 2,5-dimethoxybenzylmalonate, ethyl 2,5-dimethoxyphenylpropionate, diethyl 3,4-dimethoxybenzylmalonate, ethyl 3,4-dimethoxyphenylpropionate, diethyl 3,5-dimethoxybenzylmalonate, ethyl 3,5-dimethoxyphenylpropionate, ethyl 4-hydroxy-3-methoxyphenylpropionate, diethyl 4-hydroxy-3-methoxybenzylmalonate, diethyl 3,4,5-trihydroxybenzylmalonate, ethyl 3,4,5-trihydroxyphenylpropionate, diethyl 2,4,5-trihydroxybenzylmalonate, ethyl 2,4,5-trihydroxyphenylpropionate, diethyl 2,3,4-trihydroxybenzylmalonate, ethyl 2,3,4-trihydroxyphenylpropionate, diethyl 2,4-dihydroxybenzylmalonate, ethyl 2,4-dihydroxyphenylpropionate, diethyl 2,3-dihydroxybenzylmalonate, ethyl 2,3-dihydroxyphenylpropionate, diethyl 2,5-dihydroxybenzylmalonate, ethyl 2,5-dihydroxyphenylpropionate, diethyl 3,4-dihydroxybenzylmalonate, ethyl 3,4-dihydroxyphenylpropionate, diethyl 3,5-dihydroxybenzylmalonate, ethyl 3,5-dihydroxyphenylpropionate, ethyl 3-hydroxy-4-methoxyphenylpropionate, diethyl 3-hydroxy-4-methoxybenzylmalonate, diphenethyl 4-methoxybenzylmalonate, phenethyl 4-methoxyphenylpropionate, phenethyl 4-hydroxy-3,5-dimethoxyphenylpropionate, diphenethyl 3,4,5-trimethoxybenzylmalonate, phenethyl 3,4,5-trimethoxyphenylpropionate, diphenethyl 2,4,5-trimethoxybenzylmalonate, phenethyl 2,4,5-trimethoxyphenylpropionate, diphenethyl 2,3,4-trimethoxybenzylmalonate, phenethyl 2,3,4-trimethoxyphenylpropionate, diphenethyl 2,3,5-trimethoxybenzylmalonate, phenethyl 2,3,5-trimethoxyphenylpropionate, diphenethyl 2,3,6-trimethoxybenzylmalonate, phenethyl 2,3,6-trimethoxyphenylpropionate, diphenethyl 2,4,6-trimethoxybenzylmalonate, phenethyl 2,4,6-trimethoxyphenylpropionate, diphenethyl 2,4-dimethoxybenzylmalonate, phenethyl 2,4-dimethoxyphenylpropionate, diphenethyl 2,3-dimethoxybenzylmalonate, phenethyl 2,3-dimethoxyphenylpropionate, diphenethyl 2,5-dimethoxybenzylmalonate, phenethyl 2,5-dimethoxyphenylpropionate, diphenethyl 3,4-dimethoxybenzylmalonate, phenethyl 3,4-dimethoxyphenylpropionate, diphenethyl 3,5-dimethoxybenzylmalonate, phenethyl 3,5-dimethoxyphenylpropionate, phenethyl 4-hydroxy-3-methoxyphenylpropionate, diphenethyl 4-hydroxy-3-methoxybenzylmalonate, diphenethyl 3,4,5-trihydroxybenzylmalonate, phenethyl 3,4,5-trihydroxyphenylpropionate, diphenethyl 2,4,5-trihydroxybenzylmalonate, phenethyl 2,4,5-trihydroxyphenylpropionate, diphenethyl 2,3,4-trihydroxybenzylmalonate, phenethyl 2,3,4-trihydroxyphenylpropionate, diphenethyl 2,4-dihydroxybenzylmalonate, phenethyl 2,4-dihydroxyphenylpropionate, diphenethyl 2,3-dihydroxybenzylmalonate, phenethyl 2,3-dihydroxyphenylpropionate, diphenethyl 2,5-dihydroxybenzylmalonate, phenethyl 2,5-dihydroxyphenylpropionate, diphenethyl 3,4-dihydroxybenzylmalonate, phenethyl 3,4-dihydroxyphenylpropionate, diphenethyl 3,5-dihydroxybenzylmalonate, phenethyl 3,5-dihydroxyphenylpropionate, phenethyl 3-hydroxy-4-methoxyphenylpropionate, diphenethyl 3-hydroxy-4-methoxybenzylmalonate, ethyl 2-cyano-3,3-diphenylpropionate, 2-ethylhexyl 2-cyano-3,3-diphenylpropionate, 2-cyano-3,3-diphenylpropionic acid, chloride of N,N′-bis[3-(ethyldimethylammonium)propyl]-2-(4-hydroxy-3,5-dimethoxybenzyl)malonamide, chloride of N,N′-bis[3-(ethyldimethylammonium)ethyl]-2-(4-hydroxy-3,5-dimethoxybenzyl)malonamide, chloride of N,N′-bis[3-(trimethylammonium)propyl]-2-(4-hydroxy-3,5-dimethoxybenzyl)malonamide, chloride of N,N′-bis[3-(trimethylammonium)ethyl]-2-(4-hydroxy-3,5-dimethoxybenzyl)malonamide, chloride of N,N′-bis[3-(ethyldimethylammonium)propyl]-2-(4-hydroxy-3-methoxybenzyl)malonamide, chloride of N,N′-bis[3-(ethyldimethylammonium)ethyl]-2-(4-hydroxy-3-methoxybenzyl)malonamide, chloride of N,N′-bis[3-(trimethylammonium)propyl]-2-(4-hydroxy-3-methoxybenzyl)malonamide, chloride of N,N′-bis[3-(trimethylammonium)ethyl]-2-(4-hydroxy-3-methoxybenzyl)malonamide, oligo- and polysiloxanes which contain benzylmalonic acid derivatives or phenylpropionic acid derivatives bonded via alkyleneoxy functions, such as, for example, diethyl 4-alkyleneoxybenzylmalonate. Example 3 Oxidation in UV Light FIG. 1 shows the change in the UV spectrum of di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylmalonate (from Example 1) on irradiation with UV light. The curves stand for the unirradiated substance (exposed to 0 kJ/m2), after irradiation for 15 min (exposure to 86 kJ/m2), after irradiation for 65 min (exposure to 373 kJ/m2), after irradiation for 235 min (exposure to 1349 kJ/m2) and after irradiation for 405 min (exposure to 2325 kJ/m2). The spectra are recorded on a Carry 300 bio spectrometer. The irradiation is carried out by means of an Atlas Sun Test CPS, xenon lamp with UV special-glass filter at a power of 95.69 W/m2 in the range 290-400 nm. After only 65 min, a significantly increased UV absorption by the compound in the UV-A region (Emax in the range 320-340 nm), which increases further on longer irradiation, is evident. Example 3a Oxidation in UV Light in the Presence of Further Antioxidants FIG. 2 shows the change in the UV/VIS spectrum of emulsions comprising 0.5% by weight of beta-carotene and 4% by weight of di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylmalonate (curves A and B) compared with an emulsion comprising 0.5% by weight of beta-carotene, but no di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylmalonate (curves C and D) on irradiation with UV light (cf. Example 3). The curves stand for the unirradiated emulsions (curves A and C) and the emulsions after irradiation for 90 min (curves B and D). The spectra are recorded on a Carry 50 spectrometer. The irradiation is carried out by means of an Atlas Sun Test CPS+ xenon lamp with UV special-glass filter. The results are from 4-fold determinations (n=4). For the irradiated sample (B) comprising di-2-ethylheyl 4-hydroxy-3,5-dimethoxybenzylmalonate, the absorption of the reaction product in the UVA region (Emax in the range 320-340 nm) is again evident. In addition, however, it can be seen that the absorption of the beta-carotene (Emax in the range 440-480 nm) in this sample is significantly stronger compared with the irradiated sample D. Consequently, beta-carotene degradation in the emulsion according to the invention is reduced; di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylmalonate stabilises the beta-carotene. Example 3b DPPH Assay The free-radical-reducing action can be shown, for example, by means of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. 2,2-Diphenyl-1-picrylhydrazyl is a free radical which is stable in solution. The unpaired electron results in a strong absorption band at 515 nm, and the solution has a dark-violet colour. In the presence of a free-radical scavenger, the electron is paired, the absorption disappears, and the decoloration proceeds stoichiometrically taking into account the electrons taken up. The absorbance is measured in a photometer. The anti-free-radical property of the substance to be tested is determined by measuring the concentration at which 50% of the 2,2-diphenyl-1-picrylhydrazyl employed have reacted with the free-radical scavenger. This concentration is expressed as EC50, a value which should be regarded as a substance property under the given measurement conditions. The substance investigated is compared with a standard (for example tocopherol). The EC50 value here is a measure of the capacity of the respective compound to scavenge free radicals. The lower the EC50 value, the higher the capacity to scavenge free radicals. Procedure: A stock solution of 2,2-diphenyl-1-picrylhydrazyl (DPPH) in ethanol is prepared (0.025 g/l of DPPH free radicals). Various concentrations of the compound to be tested are added to aliquots of this solution. The absorbance is measured in each case at 515 nm, 25° C. and 1 cm. The EC50 determined is the value at which 50% of the original DPPH free-radical concentration is still present. The lower this value, the higher the corresponding free-radical-reducing activity. The reaction time needed to achieve this value is indicated in the value TEC50 (in minutes). The table compares activities and stabilities of some common antioxidants (determined in accordance with the DPPH assay described above) with the antioxidants according to the invention. Activity Stability EC50 TEC50 [μmol/l] [min] Hydroxy dimethoxybenzyl malonate 0.30 600 Hydroxy dimethoxybenzylidene malonate 6.66 1200 Ascorbic acid 0.29 <5 Ascorbyl (2-O) phosphate 8.61 1200 alpha-Tocopherol 0.25 30 alpha-Tocopheryl acetate 5040 600 Example 4 Compositions Illustrative formulations of cosmetic compositions which comprise compounds according to Example 1 or 2 are indicated below. Corresponding compositions can be prepared in the same way with all compounds according to the invention. In addition, the INCI names of the commercially available compounds are indicated. UV-Pearl, OMC stands for the composition having the INCI name: Water (for EU: Aqua), Ethylhexyl Methoxycinnamate, Silica, PVP, Chlorphenesin, BHT; this composition is commercially available from Merck KGaA, Darmstadt, under the name Eusolex®UV Pearl™ OMC. The other UV-Pearls indicated in the tables each have an analogous composition, with OMC being replaced by the UV filters indicated. TABLE 1 W/O emulsions (numbers in % by weight) 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 Titanium Dioxide 2 5 3 Di-2-ethylhexyl 4-hydroxy- 5 3 2 1 2 1 2 1 1 1 3,5-dimethoxybenzyl- malonate Zinc Oxide 5 2 UV-Pearl, OMC 30 15 15 15 15 15 15 15 15 15 Polyglyceryl 3-Dimerate 3 3 3 3 3 3 3 3 3 3 Cera Alba 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Hydrogenated Castor Oil 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Paraffinium Liquidum 7 7 7 7 7 7 7 7 7 7 Caprylic/Capric Triglyceride 7 7 7 7 7 7 7 7 7 7 Hexyl Laurate 4 4 4 4 4 4 4 4 4 4 PVP/Eicosene Copolymer 2 2 2 2 2 2 2 2 2 2 Propylene Glycol 4 4 4 4 4 4 4 4 4 4 Magnesium Sulfate 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Tocopherol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Tocopheryl Acetate 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Cyclomethicone 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Propylparaben 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 1-11 1-12 1-13 1-14 1-15 1-16 1-17 1-18 Titanium Dioxide 3 2 3 2 5 Benzylidene Malonate Polysiloxane 1 0.5 2-Ethylhexyl 4-hydroxyphenyl- 1 1 0.5 propionate Di-2-ethylhexyl 4-hydroxy-3,5- 5 3 2 5 1 3 7 2 dimethoxybenzylmalonate Polyglyceryl 3-Dimerate 3 3 3 3 Cera Alba 0.3 0.3 0.3 0.3 2 2 2 2 Hydrogenated Castor Oil 0.2 0.2 0.2 0.2 Paraffinium Liquidum 7 7 7 7 Caprylic/Capric Triglyceride 7 7 7 7 Hexyl Laurate 4 4 4 4 PVP/Eicosene Copolymer 2 2 2 2 Propylene Glycol 4 4 4 4 Magnesium Sulfate 0.6 0.6 0.6 0.6 Tocopherol 0.5 0.5 0.5 0.5 Tocopheryl Acetate 0.5 0.5 0.5 0.5 1 1 1 1 Cyclomethicone 0.5 0.5 0.5 0.5 Propylparaben 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Dicocoyl Pentyerythrityl Citrate (and) 6 6 6 6 Sorbitan Sesquioleate (and) Cera Alba (and) Aluminium Stearate PEG-7 Hydrogenated Castor Oil 1 1 1 1 Zinc Stearate 2 2 2 2 Oleyl Erucate 6 6 6 6 Decyl Oleate 6 6 6 6 Dimethicone 5 5 5 5 Tromethamine 1 1 1 1 Glycerin 5 5 5 5 Allantoin 0.2 0.2 0.2 0.2 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 1-19 1-20 1-21 1-22 1-23 1-24 1-25 1-26 1-27 1-28 1-29 Titanium Dioxide 2 5 3 3 Benzylidene Malonate Polysiloxane 1 1 1 Methylene Bis-Benzotriazolyl 1 2 1 1 Tetramethylbutylphenol Zinc Oxide 5 2 2-Ethylhexyl 4-hydroxyphenyl- 5 5 5 5 7 5 5 5 5 5 8 propionate UV-Pearl, OCR 10 5 UV-Pearl, EthylhexylDimethylPABA 10 Di-2-ethylhexyl 4-hydroxy-3,5- 2 4 5 6 3 1 6 10 1 2 5 dimethoxybenzylmalonate UV-Pearl, Homosalate, BP-3 10 UV-Pearl, Ethylhexyl Salicylate, 10 BP-3 BMDBM 2 UV-Pearl OMC, 25 4-Methylbenzylidene Camphor Polyglyceryl 3-Dimerate 3 3 3 3 3 3 3 3 3 3 3 Cera Alba 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Hydrogenated Castor Oil 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Paraffinium Liquidum 7 7 7 7 7 7 7 7 7 7 7 Caprylic/Capric Triglyceride 7 7 7 7 7 7 7 7 7 7 7 Hexyl Laurate 4 4 4 4 4 4 4 4 4 4 4 PVP/Eicosene Copolymer 2 2 2 2 2 2 2 2 2 2 2 Propylene Glycol 4 4 4 4 4 4 4 4 4 4 4 Magnesium Sulfate 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Tocopherol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Tocopheryl Acetate 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Phenethyl 3,4-dihydroxyphenyl- 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 propionate Propylparaben 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Water to 100 TABLE 2 O/W emulsions, numbers in % by weight 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 2-10 Titanium Dioxide 2 5 3 Methylene Bis-Benzotriazolyl 1 2 1 Tetramethylbutylphenol Phenethyl 3,4-Dihydroxyphenyl- 1 2 1 1 propionate 2-Ethylhexyl 4-Hydroxyphenyl- 1 3 2 5 5 2 propionate Di-2-ethylhexyl 4-Hydroxy-3,5- 5 5 5 5 5 5 5 5 5 5 dimethoxybenzylmalonate Di-2-ethylhexyl 2-Cyano-3,3- 1 5 4 6 7 2 1 diphenylpropionate 4-Methylbenzylidene Camphor 2 3 4 3 2 BMDBM 1 3 3 3 3 3 3 Stearyl Alcohol (and) Steareth-7 3 3 3 3 3 3 3 3 3 3 (and) Steareth-10 Glyceryl Stearate (and) Ceteth- 3 3 3 3 3 3 3 3 3 3 20 Glyceryl Stearate 3 3 3 3 3 3 3 3 3 3 Microwax 1 1 1 1 1 1 1 1 1 1 Cetearyl Octanoate 11.5 11.5 11.5 11.5 11.5 11.5 11.5 11.5 11.5 11.5 Caprylic/Capric Triglyceride 6 6 6 6 6 6 6 6 6 6 Oleyl Oleate 6 6 6 6 6 6 6 6 6 6 Propylene Glycol 4 4 4 4 4 4 4 4 4 4 Glyceryl Stearate SE Stearic Acid Persea Gratissima Propylparaben 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Tromethamine 1.8 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 2-11 2-12 2-13 2-14 2-15 2-16 2-17 2-18 Titanium Dioxide 3 2 2 5 Benzylidene Malonate Polysiloxane 1 0.5 Phenethyl 3,4-Dihydroxyphenyl- 1 1 0.5 propionate Di-2-ethylhexyl 4-Hydroxy-3,5- 1 2 dimethoxybenzylmalonate Di-2-ethylhexyl 2-Cyano-3,3- 1 3 2 5 5 diphenylpropionate 5,6,7-Trihydroxyflavone 5 5 5 5 5 5 5 5 2-Ethylhexyl 4-Hydroxyphenyl- 1 5 4 6 7 propionate Zinc Oxide 2 UV-Pearl, OMC 15 15 15 30 30 30 15 15 4-Methylbenzylidene Camphor 3 BMDBM 1 Phenylbenzimidazole Sulfonic Acid 4 Stearyl Alcohol (and) Steareth-7 3 3 3 3 (and) Steareth-10 Glyceryl Stearate (and) Ceteth-20 3 3 3 3 Glyceryl Stearate 3 3 3 3 Microwax 1 1 1 1 Cetearyl Octanoate 11.5 11.5 11.5 11.5 Caprylic/Capric Triglyceride 6 6 6 6 14 14 14 14 Oleyl Oleate 6 6 6 6 Propylene Glycol 4 4 4 4 Glyceryl Stearate SE 6 6 6 6 Stearic Acid 2 2 2 2 Persea Gratissima 8 8 8 8 Propylparaben 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Tromethamine 1.8 Glycerin 3 3 3 3 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 2-19 2-20 2-21 2-22 2-23 2-24 2-25 2-26 2-27 2-28 Titanium Dioxide 3 3 2 Benzylidene Malonate 1 2 1 1 1 0.5 Polysiloxane 7,8,3′,4′-Tetrahydroxyflavone 1 2 1 1 2-Ethylhexyl 4-Hydroxyphenyl- 1 3 2 5 5 2 propionate Di-2-ethylhexyl 2-Cyano-3,3- 5 5 5 5 5 5 5 5 5 5 diphenylpropionate Di-2-ethylhexyl 4-Hydroxy-3,5- 1 5 4 6 7 2 1 dimethoxybenzylmalonate Phenethyl 3,4-Dihydroxy- 1 2 1 1 1 0.5 phenylpropionate Zinc Oxide 5 2 2 UV-Pearl, OMC 15 15 15 15 15 15 15 15 15 15 Caprylic/Capric Triglyceride 14 14 14 14 14 14 14 14 14 14 Oleyl Oleate Propylene Glycol Glyceryl Stearate SE 6 6 6 6 6 6 6 6 6 6 Stearic Acid 2 2 2 2 2 2 2 2 2 2 Persea Gratissima 8 8 8 8 8 8 8 8 8 8 Propylparaben 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Glyceryl Stearate, Ceteareth- 20, Ceteareth-10, Cetearyl Alcohol, Cetyl Palmitate Ceteareth-30 Dicaprylyl Ether Glycerin 3 3 3 3 3 3 3 3 3 3 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 TABLE 3 Gels, numbers in % by weight 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9 3-10 A = aqueous gel Titanium Dioxide 2 5 3 5,6,7-Trihydroxyflavone 1 2 1 1 Di-2-ethylhexyl 4-Hydroxy-3,5- 1 3 2 5 5 2 dimethoxybenzylmalonate Di-2-ethylhexyl 2-Cyano-3,3- 5 5 5 5 5 5 5 5 5 5 diphenylpropionate 2-Ethylhexyl 4-Hydroxyphenyl- 1 5 4 6 7 2 1 propionate Benzylidene Malonate Polysiloxane 1 1 2 1 1 Methylene Bis-Benzotriazolyl 1 1 2 1 Tetramethylbutylphenol Zinc Oxide 2 5 2 UV-Pearl, Ethylhexyl 30 15 15 15 15 15 15 15 15 15 Methoxycinnamate 4-Methylbenzylidene Camphor 2 Butylmethoxydibenzoylmethane 1 Phenylbenzimidazole Sulfonic Acid 4 Prunus Dulcis 5 5 5 5 5 5 5 5 5 5 Tocopheryl Acetate 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Caprylic/Capric Triglyceride 3 3 3 3 3 3 3 3 3 3 Octyldodecanol 2 2 2 2 2 2 2 2 2 2 Decyl Oleate 2 2 2 2 2 2 2 2 2 2 PEG-8 (and) Tocopherol (and) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Ascorbyl Palmitate (and) Ascorbic Acid (and) Citric Acid Sorbitol 4 4 4 4 4 4 4 4 4 4 Polyacrylamide (and) C13-14 3 3 3 3 3 3 3 3 3 3 Isoparaffin (and) Laureth-7 Propylparaben 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Tromethamine 1.8 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 3-11 3-12 3-13 3-14 3-15 3-16 3-17 3-18 a = aqueous gel A a a a a Titanium Dioxide 3 2 Benzylidene Malonate Polysiloxane 1 0.5 1 2 Methylene Bis-Benzotriazolyl 1 1 0.5 1 2 1 Tetramethylbutylphenol Di-2-ethylhexyl 4-Hydroxy-3,5- 1 2 dimethoxybenzylmalonate 2-Ethylhexyl 4-Hydroxyphenylpropionate 1 3 2 5 5 Di-2-ethylhexyl 2-Cyano-3,3-diphenyl- 5 5 5 5 5 5 5 5 propionate 6,3′,4′-Trihydroxyflavone 1 5 4 6 7 Zinc Oxide 2 UV-Pearl, Ethylhexyl Methoxycinnamate 15 15 15 15 15 15 15 15 Prunus Dulcis 5 5 5 Tocopheryl Acetate 0.5 0.5 0.5 Caprylic/Capric Triglyceride 3 3 3 Octyldodecanol 2 2 2 Decyl Oleate 2 2 2 PEG-8 (and) Tocopherol (and) Ascorbyl 0.05 0.05 0.05 Palmitate (and) Ascorbic Acid (and) Citric Acid Sorbitol 4 4 4 5 5 5 5 5 Polyacrylamide (and) C13-14 3 3 3 Isoparaffin (and) Laureth-7 Carbomer 1.5 1.5 1.5 1.5 1.5 Propylparaben 0.05 0.05 0.05 Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Allantoin 0.2 0.2 0.2 0.2 0.2 Tromethamine 2.4 2.4 2.4 2.4 2.4 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 3-19 3-20 3-21 3-22 3-23 3-24 3-25 3-26 3-27 3-28 7,8,3′,4′-Tetrahydroxyflavone 1 2 1 1 Di-2-ethylhexyl 4-Hydroxy-3,5- 1 3 2 5 5 2 dimethoxybenzylmalonate Di-2-ethylhexyl 2-Cyano-3,3- 5 5 5 5 5 5 5 5 5 5 diphenylpropionate 2-Ethylhexyl 4-Hydroxyphenyl- 1 5 4 6 7 2 1 propionate UV-Pearl, OMC 30 30 15 15 15 11 12 15 15 15 Phenylbenzimidazole Sulfonic 4 4 Acid Sorbitol 5 5 5 5 5 5 5 5 5 5 Carbomer 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Propylparaben Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Allantoin 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Tromethamine 2.4 4.2 4.2 2.4 2.4 2.4 2.4 2.4 2.4 2.4 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 3-29 3-30 3-31 3-32 3-33 3-34 3-35 3-36 2-Ethylhexyl 4-Hydroxyphenylpropionate 1 2 Di-2-ethylhexyl 2-Cyano-3,3-diphenylpropionate 1 3 2 5 5 Di-2-ethylhexyl 4-Hydroxy-3,5-dimethoxybenzyl- 5 5 5 5 5 5 5 5 malonate 5,6,7-Trihydroxyflavone 1 5 4 6 7 UV-Pearl, OMC 15 10 10 10 10 15 10 UV-Pearl, OCR 10 UV-Pearl, OMC, Methylene Bis-Benzotriazolyl 7 6 Tetramethylbutylphenol UV-Pearl, Ethylhexyl Salicylate, BMDBM 10 Disodium Phenyl Dibenzimidazole 3 3 3 Tetrasulfonate Phenylbenzimidazole Sulfonic Acid 2 2 3 3 Prunus Dulcis 5 5 5 Tocopheryl Acetate 0.5 0.5 0.5 Caprylic/Capric Triglyceride 3 3 3 Octyldodecanol 2 2 2 Decyl Oleate 2 2 2 PEG-8 (and) Tocopherol (and) Ascorbyl 0.05 0.05 0.05 Palmitate (and) Ascorbic Acid (and) Citric Acid Sorbitol 4 4 4 5 5 5 5 5 Polyacrylamide (and) C13-14 Isoparaffin (and) 3 3 3 Laureth-7 Carbomer 1.5 1.5 1.5 1.5 1.5 Propylparaben 0.05 0.05 0.05 Methylparaben 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 Allantoin 0.2 0.2 0.2 0.2 0.2 Tromethamine 2.4 2.4 2.4 2.4 2.4 Water to 100 to 100 to 100 to 100 to 100 to 100 to 100 to 100 Example 5 Hair Mascara Ingredients [%] A PEARLESCENT PIGMENT 20.00 B CETEARETH-25 1.80 CETEARYL ALCOHOL 5.00 DIMETHICONE 1.00 PHENOXYETHANOL, BUTYLPARABEN, 0.50 ETHYLPARABEN, PROPYLPARABEN, METHYLPARABEN C AQUA (WATER) to 100 POLYQUATERNIUM-16 3.0 PROPYLENE GLYCOL 1.80 COMPOUND OF FORMULA IB-IAH 0.5 D AQUA (WATER) 9.50 HYDROXYPROPYLCELLULOSE 0.50 E AQUA (WATER) 9.50 MAGNESIUM ALUMINIUM SILICATE 0.50 IMIDAZOLIDINYL UREA 0.30 Preparation Process: Heat phase B to 75° C., phase C to 80° C. Slowly add phase B to phase C with stirring. Cool to 65° C. with stirring, and homogenise. Cool to 40° C., and add phases D, E and F to phase B/C with stirring, and again homogenise. Now add the pearlescent pigment with stirring. Cool to room temperature, and adjust the pH to 6.0-6.5. Hair mascara compositions which have the following modifications can be prepared analogously: POLYQUATERNIUM-16 0 COMPOUND OF FORMULA IB-IAH 4.0 POLYQUATERNIUM-16 0.5 COMPOUND OF FORMULA IB-IAH 3.0 POLYQUATERNIUM-16 1 COMPOUND OF FORMULA IB-IAH 3 POLYQUATERNIUM-16 1 COMPOUND OF FORMULA IB-IAH 3.5 POLYQUATERNIUM-16 2 COMPOUND OF FORMULA IB-IAH 2 POLYQUATERNIUM-16 1.5 COMPOUND OF FORMULA IB-IAH 1 POLYQUATERNIUM-16 2.5 COMPOUND OF FORMULA IB-IAH 1.5 POLYQUATERNIUM-16 1 COMPOUND OF FORMULA IB-IAH 2.5 Example 6 Conditioner Comprising IR3535® Ingredients [%] A ETHYLBUTYL ACETYLAMINOPROPIONATE 10.00 PVP/VA COPOLYMER 4.00 PERFUME 0.30 QUATERNIUM-80 1.0 PEG-40 HYDROGENATED CASTOR OIL 1.00 ALCOHOL 15.00 COMPOUND OF FORMULA IB-IAH 2.0% B CETRIMONIUM CHLORIDE 0.50 AQUA (WATER) To 100 C COCAMIDOPROPYL BETAINE 4.00 Preparation process: Mix phases A and B separately. Add phase B to phase A with stirring. Add phase C. Conditioner compositions which have the following modifications can be prepared analogously: QUATERNIUM-80 2.0 COMPOUND OF FORMULA IB-IAH 1.0 QUATERNIUM-80 0 COMPOUND OF FORMULA IB-IAH 3.0 QUATERNIUM-80 1.0 COMPOUND OF FORMULA IB-IAH 2.5 QUATERNIUM-80 2.0 COMPOUND OF FORMULA IB-IAH 1.5 QUATERNIUM-80 2.0 COMPOUND OF FORMULA IB-IAH 3.0 QUATERNIUM-80 0.5 COMPOUND OF FORMULA IB-IAH 2.5 QUATERNIUM-80 1.0 COMPOUND OF FORMULA IB-IAH 3.0 QUATERNIUM-80 2.5 COMPOUND OF FORMULA IB-IAH 1.5 QUATERNIUM-80 1.8 COMPOUND OF FORMULA IB-IAH 2.1 Example 7 Hair Conditioner Comprising Pearlescent Pigment Ingredients [%] A PEARLESCENT PIGMENT 3.00 DISODIUM EDTA 0.05 AQUA (WATER) to 100 B CETEARYL ALCOHOL, BEHENTRIMONIUM 5.00 METHOSULFATE OCTYLDODECANOL 1.10 CETYL ALCOHOL 1.00 GLYCERIN 1.00 BEHENTRIMONIUM CHLORIDE 0.70 METHOXY PEG/PPG-7/3 AMINOPROPYL 0.70 DIMETHICONE QUATERNIUM-80 1.0 COMPOUND OF FORMULA IB-IAH 2.0 C COCODIMONIUM HYDROXYPROPYLSILICAMINO 0.70 ACIDS PHENOXYETHANOL, BENZOIC ACID, 0.40 DEHYDROACETIC ACID CITRIC ACID 0.20 PERFUME 0.60 Preparation Process: Disperse the pearlescent pigment and Titriplex III in the water of phase A. Heat the constituents of phases A and B to 75° C. Add phase B to phase A with stirring, and homogenise. Cool to 40° C., and add the constituents of phase C. Cool to 30° C., and again homogenise for about 30 sec. Adjust the pH to 3.6-4.0. Notes: recommended pearlescent pigments are TIMIRON® silver pigments and TIMIRON® interference pigments from Merck. Conditioner compositions which have the following modifications can be prepared analogously to Example 7: QUATERNIUM-80 2.0 COMPOUND OF FORMULA IB-IAH 1.0 QUATERNIUM-80 0 COMPOUND OF FORMULA IB-IAH 3.0 QUATERNIUM-80 1.0 COMPOUND OF FORMULA IB-IAH 2.5 QUATERNIUM-80 2.0 COMPOUND OF FORMULA IB-IAH 1.5 QUATERNIUM-80 2.0 COMPOUND OF FORMULA IB-IAH 3.0 QUATERNIUM-80 0.5 COMPOUND OF FORMULA IB-IAH 2.5 QUATERNIUM-80 1.0 COMPOUND OF FORMULA IB-IAH 3.0 QUATERNIUM-80 2.5 COMPOUND OF FORMULA IB-IAH 1.5 QUATERNIUM-80 1.8 COMPOUND OF FORMULA IB-IAH 2.1 Index of the Figures FIGS. 1a and 1b: FIG. 1 (FIG. 1b represents a detail of FIG. 1a) shows the change in the UV spectrum of di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylmalonate on irradiation with UV light (cf. Example 3): the curves stand for the unirradiated substance (exposed to 0 kJ/m2), after irradiation for 15 min (exposure to 86 kJ/m2), after irradiation for 65 min (exposure to 373 kJ/m2), after irradiation for 235 min (exposure to 1349 kJ/m2) and after irradiation for 405 min (exposure to 2325 kJ/m2). The spectra are recorded on a Carry 300 bio spectrometer. The irradiation is carried out by means of an Atlas Sun Test CPS, xenon lamp with UV special-glass filter at a power of 95.69 W/m2 in the range 290-400 nm. The results are from 4-fold determinations (n=4). FIG. 2: FIG. 2 shows the change in the UV/VIS spectrum of emulsions comprising 0.5% by weight of beta-carotene and 4% by weight of di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylmalonate (curves A and B) compared with an emulsion comprising 0.5% by weight of beta-carotene, but no di-2-ethylhexyl 4-hydroxy-3,5-dimethoxybenzylmalonate (curves C and D) on irradiation with UV light (cf. Example 3a): the curves stand for the unirradiated emulsions (curves A and C) and the emulsions after irradiation for 90 min (curves B and D). The spectra are recorded on a Carry 300 bio spectrometer. The irradiation is carried out by means of an Atlas Sun Test CPS, xenon lamp with UV special-glass filter at a power of 95.69 W/m2 in the range 290-400 nm. The results are from 4-fold determinations (n=4).
|
A
|
A61
|
A61K
|
8
|
44
|
|||||
11919658
|
US20100071646A1-20100325
|
Engine
|
ACCEPTED
|
20100310
|
20100325
|
[]
|
F01L102
|
["F01L102", "F02B7700", "B21D3903"]
|
8430076
|
20071031
|
20130430
|
123
|
193500
|
62033.0
|
MCMAHON
|
MARGUERITE
|
[{"inventor_name_last": "Kono", "inventor_name_first": "Shohei", "inventor_city": "Saitama", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Hashimoto", "inventor_name_first": "Manabu", "inventor_city": "Saitama", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Honda", "inventor_name_first": "Souhei", "inventor_city": "Saitama", "inventor_state": "", "inventor_country": "JP"}]
|
An engine includes: a crankshaft 12; a camshaft 36; and a timing transmission system 37 which has a drive rotation member 45, a driven rotation member 46, and an endless power transmission member 47, and which provides connection between the crankshaft 12 and the camshaft 36. An access window 55 through which the driven rotation member 46 is attached to and detached from the camshaft 36 is opened in an outer end surface 5c of the cylinder head 5. A lid body 57 for closing the access window 55 is jointed to the outer end surface 5c. The outer end surface 5c of the cylinder head 5 comprises a slanted surface 5c which is inclined so that at least a part of an outer periphery of the driven rotation member 46 on a side opposite from the drive rotation member 45 is exposed from the access window 55. Thus, it is possible to facilitate the operation of attaching the endless power transmission member to the driven rotation member and mounting the driven rotation member to the camshaft, and also contributing to downsizing of the engine.
|
1. An engine comprising: a crankshaft (12) supported on a crankcase (2); a valve-operating camshaft (36) supported on a cylinder head (5); and a timing transmission system (37) which includes a drive rotation member (45) fixedly mounted to the crankshaft (12), a driven rotation member (46) fixedly mounted to the camshaft (36), and an endless power transmission member (47) wound around the two rotation members (45, 46), and which provides connection between the crankshaft (12) and the valve-operating camshaft (36); an access window (55) through which the driven rotation member (46) is attached to and detached from the camshaft 36 being opened in an outer end surface (5c) of the cylinder head (5), and a lid body (57) for closing the access window (55) being jointed to the outer end surface (5c) of the cylinder head (5), characterized in that the outer end surface (5c) of the cylinder head (5) comprises a slanted surface (5c) which is inclined so that at least a part of an outer periphery of the driven rotation member (46) on a side opposite from the drive rotation member (45) is exposed from the access window (55). 2. The engine according to claim 1, wherein the slanted surface (5c) is formed so that a half-round portion or more of the driven rotation member (46) on the side opposite from the drive rotation member (45) is exposed from the access window (55). 3. The engine according to claim 1, wherein the cylinder head (5) is superposed, via a gasket (4), on a cylinder block (3) which is connected to the crankcase (2) and which includes a cylinder bore (3a) and a timing transmission chamber (48) that is present on one side of the cylinder bore (3a) and houses the timing transmission system (37); the cylinder head (5) is fastened to the cylinder block (4) by a plurality of main connecting bolts (6) arranged around the cylinder bore (3a); and the cylinder head (5) is fastened to the cylinder block (4) at a portion outward of one side of the timing transmission chamber (48) by an auxiliary connecting bolt (7) disposed below the access window (55). 4. The engine according to claim 1, wherein a side wall of the lid body (57) is inclined along the slanted surface (5c) of the cylinder head (5). 5. The engine according to claim 1, further comprising: a first match mark (62a) indicated on an outer side surface of the driven rotation member (46); a second match mark (62b) indicated on an engine main body (1) so as to coincide with the first match mark (62a) when the crankshaft (12) is in a predetermined rotational position; a bolt hole (60) provided in an end wall of a hub (46a) of the driven rotation member (46) which is fitted into an end portion of the camshaft (36); a positioning groove (61) extending radially from the bolt hole (60); a positioning pin (67) projectingly provided on an end surface of the camshaft (36) in a position eccentric from a center of the end surface in a certain direction, and engaged with the positioning groove (61) when the camshaft (36) is in a predetermined phase relationship to the crankshaft (12) in the predetermined rotational position; a threaded hole (66) which is provided on the end surface of the camshaft (36) and corresponds to the bolt hole (60) when the camshaft (36) is in a predetermined phase relationship to the crankshaft (12) in the predetermined rotational position; and a mounting bolt (68) penetrating through the bolt hole (60) and screwed into the threaded hole (66) to fix the hub (46a) to the camshaft (36). 6. The engine according to claim 1, wherein when the camshaft (36) is in the predetermined phase relationship to the crankshaft (12) in the predetermined rotational position, the first and second match marks (62a, 62b), the positioning groove (61) and the positioning pin (67) are arranged on a straight line (L) passing through centers of the crankshaft (12) and the camshaft (36). 7. The engine according to claim 1, wherein the bolt hole (60) and the threaded hole (66) are arranged in positions eccentric from centers of the hub (46a) and the camshaft (36), respectively. 8. The engine according to claim 7, wherein the threaded hole (66) and the positioning pin (67) are arranged in positions which are eccentric from the center of the camshaft (36) in directions opposite from each other. 9. The engine according to claim 2, wherein the cylinder head (5) is superposed, via a gasket (4), on a cylinder block (3) which is connected to the crankcase (2) and which includes a cylinder bore (3a) and a timing transmission chamber (48) that is present on one side of the cylinder bore (3a) and houses the timing transmission system (37); the cylinder head (5) is fastened to the cylinder block (4) by a plurality of main connecting bolts (6) arranged around the cylinder bore (3a); and the cylinder head (5) is fastened to the cylinder block (4) at a portion outward of one side of the timing transmission chamber (48) by an auxiliary connecting bolt (7) disposed below the access window (55). 10. The engine according to claim 2, wherein a side wall of the lid body (57) is inclined along the slanted surface (5c) of the cylinder head (5). 11. The engine according to claim 2, further comprising: a first match mark (62a) indicated on an outer side surface of the driven rotation member (46); a second match mark (62b) indicated on an engine main body (1) so as to coincide with the first match mark (62a) when the crankshaft (12) is in a predetermined rotational position; a bolt hole (60) provided in an end wall of a hub (46a) of the driven rotation member (46) which is fitted into an end portion of the camshaft (36); a positioning groove (61) extending radially from the bolt hole (60); a positioning pin (67) projectingly provided on an end surface of the camshaft (36) in a position eccentric from a center of the end surface in a certain direction, and engaged with the positioning groove (61) when the camshaft (36) is in a predetermined phase relationship to the crankshaft (12) in the predetermined rotational position; a threaded hole (66) which is provided on the end surface of the camshaft (36) and corresponds to the bolt hole (60) when the camshaft (36) is in a predetermined phase relationship to the crankshaft (12) in the predetermined rotational position; and a mounting bolt (68) penetrating through the bolt hole (60) and screwed into the threaded hole (66) to fix the hub (46a) to the camshaft (36). 12. The engine according to claim 3, further comprising: a first match mark (62a) indicated on an outer side surface of the driven rotation member (46); a second match mark (62b) indicated on an engine main body (1) so as to coincide with the first match mark (62a) when the crankshaft (12) is in a predetermined rotational position; a bolt hole (60) provided in an end wall of a hub (46a) of the driven rotation member (46) which is fitted into an end portion of the camshaft (36); a positioning groove (61) extending radially from the bolt hole (60); a positioning pin (67) projectingly provided on an end surface of the camshaft (36) in a position eccentric from a center of the end surface in a certain direction, and engaged with the positioning groove (61) when the camshaft (36) is in a predetermined phase relationship to the crankshaft (12) in the predetermined rotational position; a threaded hole (66) which is provided on the end surface of the camshaft (36) and corresponds to the bolt hole (60) when the camshaft (36) is in a predetermined phase relationship to the crankshaft (12) in the predetermined rotational position; and a mounting bolt (68) penetrating through the bolt hole (60) and screwed into the threaded hole (66) to fix the hub (46a) to the camshaft (36). 13. The engine according to claim 4, further comprising: a first match mark (62a) indicated on an outer side surface of the driven rotation member (46); a second match mark (62b) indicated on an engine main body (1) so as to coincide with the first match mark (62a) when the crankshaft (12) is in a predetermined rotational position; a bolt hole (60) provided in an end wall of a hub (46a) of the driven rotation member (46) which is fitted into an end portion of the camshaft (36); a positioning groove (61) extending radially from the bolt hole (60); a positioning pin (67) projectingly provided on an end surface of the camshaft (36) in a position eccentric from a center of the end surface in a certain direction, and engaged with the positioning groove (61) when the camshaft (36) is in a predetermined phase relationship to the crankshaft (12) in the predetermined rotational position; a threaded hole (66) which is provided on the end surface of the camshaft (36) and corresponds to the bolt hole (60) when the camshaft (36) is in a predetermined phase relationship to the crankshaft (12) in the predetermined rotational position; and a mounting bolt (68) penetrating through the bolt hole (60) and screwed into the threaded hole (66) to fix the hub (46a) to the camshaft (36). 14. The engine according to claim 2, wherein when the camshaft (36) is in the predetermined phase relationship to the crankshaft (12) in the predetermined rotational position, the first and second match marks (62a, 62b), the positioning groove (61) and the positioning pin (67) are arranged on a straight line (L) passing through centers of the crankshaft (12) and the camshaft (36). 15. The engine according to claim 3, wherein when the camshaft (36) is in the predetermined phase relationship to the crankshaft (12) in the predetermined rotational position, the first and second match marks (62a, 62b), the positioning groove (61) and the positioning pin (67) are arranged on a straight line (L) passing through centers of the crankshaft (12) and the camshaft (36). 16. The engine according to claim 4, wherein when the camshaft (36) is in the predetermined phase relationship to the crankshaft (12) in the predetermined rotational position, the first and second match marks (62a, 62b), the positioning groove (61) and the positioning pin (67) are arranged on a straight line (L) passing through centers of the crankshaft (12) and the camshaft (36). 17. The engine according to claim 5, wherein when the camshaft (36) is in the predetermined phase relationship to the crankshaft (12) in the predetermined rotational position, the first and second match marks (62a, 62b), the positioning groove (61) and the positioning pin (67) are arranged on a straight line (L) passing through centers of the crankshaft (12) and the camshaft (36).
|
<SOH> BACKGROUND ART <EOH>Such an engine has already been known as disclosed in Patent Publication 1. Patent Publication 1: Japanese Patent Application Laid-Open No. 10-54296.
|
<SOH> BRIEF DESCRIPTION OF DRAWINGS <EOH>FIG. 1 is a sectional plan view of a general-purpose four-cycle engine according to the present invention. (first embodiment) FIG. 2 is a sectional view along line 2 - 2 in FIG. 1 . (first embodiment) FIG. 3 is a sectional view along line 3 - 3 in FIG. 1 . (first embodiment) FIG. 4 is an enlarged view of an area around a crankshaft in FIG. 1 . (first embodiment) FIG. 5 is a view from arrow 5 in FIG. 4 . (first embodiment) FIG. 6 is a sectional view along line 6 - 6 in FIG. 2 . (first embodiment) FIG. 7 is a sectional view along line 7 - 7 in FIG. 2 . (first embodiment) FIG. 8 is a sectional view along line 8 - 8 in FIG. 6 . (first embodiment) FIG. 9 is a sectional view along line 9 - 9 in FIG. 7 . (first embodiment) FIG. 10 is a view from arrow 10 in FIG. 8 . (first embodiment) FIG. 11 is a view, corresponding to FIG. 10 , in a state in which a driven pulley is removed. (first embodiment) FIG. 12 are views for describing a procedure of mounting the driven pulley on a camshaft. (first embodiment) detailed-description description="Detailed Description" end="lead"?
|
TECHNICAL FIELD The present invention relates to an improvement of an engine comprising: a crankshaft supported on a crankcase; a valve-operating camshaft supported on a cylinder head; and a timing transmission system which includes a drive rotation member fixedly mounted to the crankshaft, a driven rotation member fixedly mounted to the camshaft, and an endless power transmission member wound around the two rotation members, and which provides connection between the crankshaft and the valve-operating camshaft; an access window through which the driven rotation member is attached to and detached from the camshaft being opened in an outer end surface of the cylinder head, and a lid body for closing the access window being jointed to the outer end surface of the cylinder head. BACKGROUND ART Such an engine has already been known as disclosed in Patent Publication 1. Patent Publication 1: Japanese Patent Application Laid-Open No. 10-54296. DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the conventional engines as disclosed in Patent Publication 1, a cylinder head is formed so that an outer end surface of the cylinder head in which the access window opens is present outward in the axial direction of the driven rotation member, and hence the driven rotation member is disposed deeply inside the access window. Therefore, the operation of attaching the endless rotation member to the driven rotation member and mounting the driven rotation member to the camshaft is obstructed by the cylinder head around the driven rotation member, thus deteriorating the operability. Further, the entirety of the lid body joined to the outer end surface of the cylinder head is inevitably spaced largely away from the driven rotation member in the axial direction, thus hindering downsizing of the engine. The present invention has been achieved in view of such circumstances, and has an object to provide a compact engine exhibiting a good operability in attaching an endless rotation member to a driven rotation member and in mounting the driven rotation member to a camshaft. The present invention has another object to easily and reliably establish a predetermined phase relationship between the crankshaft and the camshaft when a timing transmission system is assembled to the crankshaft and the camshaft, in the case where the camshaft is mounted beforehand on an engine main body. Means for Solving the Problems In order to achieve the above objects, according to a first feature of the present invention, there is provided an engine comprising: a crankshaft supported on a crankcase; a valve-operating camshaft supported on a cylinder head; and a timing transmission system which includes a drive rotation member fixedly mounted to the crankshaft, a driven rotation member fixedly mounted to the camshaft; and an endless power transmission member wound around the two rotation members, and which provides connection between the crankshaft and the valve-operating camshaft; an access window through which the driven rotation member is attached to and detached from the camshaft being opened in an outer end surface of the cylinder head, and a lid body for closing the access window being jointed to the outer end surface of the cylinder head, characterized in that the outer end surface of the cylinder head comprises a slanted surface which is inclined so that at least a part of an outer periphery of the driven rotation member on a side opposite from the drive rotation member is exposed from the access window. According to a second feature of the present invention, in addition to the first feature, the slanted surface is formed so that a half-round portion or more of the driven rotation member on the side opposite from the drive rotation member is exposed from the access window. According to a third feature of the present invention, in addition to the first or second feature, the cylinder head is superposed, via a gasket, on a cylinder block which is connected to the crankcase and which includes a cylinder bore and a timing transmission chamber that is present on one side of the cylinder bore and houses the timing transmission system; the cylinder head is fastened to the cylinder block by a plurality of main connecting bolts arranged around the cylinder bore; and the cylinder head is fastened to the cylinder block at a portion outward of one side of the timing transmission chamber by an auxiliary connecting bolt disposed below the access window. According to a fourth feature of the present invention, in addition to the first or second feature, a side wall of the lid body is inclined along the slanted surface of the cylinder head. According to a fifth feature of the present invention, in addition to any of the first to fourth features, the engine further comprises: a first match mark indicated on an outer side surface of the driven rotation member; a second match mark indicated on an engine main body so as to coincide with the first match mark when the crankshaft is in a predetermined rotational position; a bolt hole provided in an end wall of a hub of the driven rotation member which is fitted into an end portion of the camshaft; a positioning groove extending radially from the bolt hole; a positioning pin projectingly provided on an end surface of the camshaft in a position eccentric from a center of the end surface in a certain direction, and engaged with the positioning groove when the camshaft is in a predetermined phase relationship to the crankshaft in the predetermined rotational position; a threaded hole which is provided on the end surface of the camshaft and corresponds to the bolt hole when the camshaft is in a predetermined phase relationship to the crankshaft in the predetermined rotational position; and a mounting bolt penetrating through the bolt hole and screwed into the threaded hole to fix the hub to the camshaft. According to a sixth feature of the present invention, in addition to the fifth feature, when the camshaft is in a predetermined phase relationship to the crankshaft in the predetermined rotational position, the first and second match marks, the positioning groove and the positioning pin are arranged on a straight line passing through centers of the crankshaft and the camshaft. According to a seventh feature of the present invention, in addition to the sixth feature, that the bolt hole and the threaded hole are arranged in positions eccentric from centers of the hub and the camshaft, respectively. According to an eighth feature of the present invention, in addition to the seventh feature, that the threaded hole and the positioning pin are arranged in positions which are eccentric from the center of the camshaft in directions opposite from each other. The drive rotation member, the driven rotation member and the endless transmission device correspond respectively to a driving pulley 45, a driven pulley 46 and a timing belt 47 in an embodiment of the present invention which will be described later. EFFECTS OF THE INVENTION With the first feature of the present invention, a part of the driven pulley exposed to outside the access window can be easily held by a tool or the like without being obstructed by the cylinder head. Therefore, the operation of mounting the driven pulley to the camshaft is facilitated, and also the removal thereof is facilitated. Therefore, this arrangement can contribute to an improvement in assemblability and maintainability. With the second feature of the present invention, the operation of attaching and detaching of the driven pulley to and from the camshaft is further facilitated, and hence the assemblability and maintainability is further improved. With the third feature of the present invention, also at a portion around the timing transmission chamber, the surface pressures of the cylinder block and the cylinder head acting on the gasket is sufficiently increased by securing the cylinder head to the cylinder block by the main connecting bolts and the auxiliary connecting bolt. Further, the presence of the slanted surface above the auxiliary connecting bolt provides a space sufficient for accepting a tool for operating the auxiliary connecting bolt, thereby facilitating the operation of fastening the auxiliary connecting bolt and contributing to downsizing of the engine. With the fourth feature of the present invention, the engine case obtains a head portion whose width is narrowing toward its tip end, thereby contributing to downsizing of the engine. With the fifth feature of the present invention, the first and second match marks, the bolt hole, the threaded hole, the positioning groove, and the positioning pin can be arranged all together on a straight line passing through the centers of the crankshaft and the camshaft, by sequentially performing the steps of: fixing the crankshaft in a rotational position corresponding to a specified position of the piston; inserting the driven rotation member into the endless power transmission member already wound around the drive rotation member, while aligning the first match mark of the driven rotation member with the second match mark of the engine main body; fitting the positioning pin of the camshaft into the bolt hole of the driven rotation member; and guiding the positioning pin to the positioning groove of the driven rotation member. Therefore, advantageously in this state where the crankshaft and the camshaft have been mounted beforehand to the engine main body, if the mounting bolt is screwed into the threaded hole of the camshaft through the bolt hole of the driven rotation member and fastened, the timing transmission system can be easily and appropriately attached to the crankshaft and the camshaft in their predetermined phase relationship. With the sixth feature of the present invention, by visually observing the state where the first and second match marks, the positioning groove, and the positioning pin are arranged on the straight line passing through the centers of the crankshaft and the camshaft, it can be easily confirmed that the crankshaft and the cam shaft have established the predetermined phase relationship therebetween. With the seventh feature of the present invention, the rotation of the driven rotation member is reliably transmitted to the camshaft via the single eccentric mounting bolt, and the mounting bolt is prevented from being loosened. With the eighth feature of the present invention, it is possible to give a sufficient amount of eccentricity to each of the bolt hole and the positioning groove which are formed on the narrow end wall of the hub of the driven rotation member, thereby improving the positioning effect of the positioning groove on the positioning pin and increasing the torque capacity of the mounting bolt. The above-mentioned object, other objects, characteristics, and advantages of the present invention will become apparent from a preferred embodiment which will be described in detail below by reference to the attached drawings. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a sectional plan view of a general-purpose four-cycle engine according to the present invention. (first embodiment) FIG. 2 is a sectional view along line 2-2 in FIG. 1. (first embodiment) FIG. 3 is a sectional view along line 3-3 in FIG. 1. (first embodiment) FIG. 4 is an enlarged view of an area around a crankshaft in FIG. 1. (first embodiment) FIG. 5 is a view from arrow 5 in FIG. 4. (first embodiment) FIG. 6 is a sectional view along line 6-6 in FIG. 2. (first embodiment) FIG. 7 is a sectional view along line 7-7 in FIG. 2. (first embodiment) FIG. 8 is a sectional view along line 8-8 in FIG. 6. (first embodiment) FIG. 9 is a sectional view along line 9-9 in FIG. 7. (first embodiment) FIG. 10 is a view from arrow 10 in FIG. 8. (first embodiment) FIG. 11 is a view, corresponding to FIG. 10, in a state in which a driven pulley is removed. (first embodiment) FIG. 12 are views for describing a procedure of mounting the driven pulley on a camshaft. (first embodiment) EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS E engine 1 engine main body 3 cylinder block 3a cylinder bore 4 gasket 5 cylinder head 5c outer end face=inclined face 6 main connecting bolt 7 auxiliary connecting bolt 12 crankshaft 35 valve operating system 36 camshaft 37 timing transmission system 45 drive rotation member (drive pulley) 46 driven rotation member (driven pulley) 46a hub 47 endless power transmission member (timing belt) 48 timing transmission chamber 48a lower chamber 48b middle chamber 48c upper chamber 55 access window 57 lid body 60 bolt hole 61 positioning groove 62a first match mark 62b second match mark 66 threaded hole 67 positioning pin 68 mounting bolt BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of the present invention is explained below with reference to the accompanying drawings. Embodiment 1 Referring first to FIG. 1 to FIG. 4, an engine main body 1 of a general-purpose four-cycle engine E includes: as components a crankcase 2 having on its lower part a mounting seat 2a; a cylinder block 3 connected integrally to the crankcase 2 and having an upwardly inclined cylinder bore 3a; and a cylinder head 5 joined to an upper end face of the cylinder block 3 via a gasket 4. Four main connecting bolts 6 disposed at four positions around the cylinder bore 3a and two auxiliary connecting bolts 7 and 7, which will be described later, are used and for joining, that is, securing the cylinder head 5 to the cylinder block 3. The crankcase 2 has one open side face; a plurality of steps 8 are formed integrally on an inner peripheral wall slightly close to the inside relative to the open side face, the steps 8 being arranged in the peripheral direction so as to face toward the open side face, and a bearing bracket 10 is secured to these steps 8 via a plurality of bolts 11. This bearing bracket 10 and another side wall of the crankcase 2 support opposite end parts of a horizontally disposed crankshaft 12 via bearings 13 and 13′. Furthermore, opposite end parts of a balancer shaft 14 disposed adjacent to and in parallel with the crankshaft 12 are similarly supported via bearings 15 and 15 by the bearing bracket 10 and said other side wall of the crankcase 2. As shown in FIG. 4 and FIG. 5, a continuous reinforcing rib 16 is formed integrally with the outer periphery of the crankcase 2 so as to surround the plurality of steps 8, and an end part of the reinforcing rib 16 is connected integrally to an outside wall of the cylinder block 3, which is integral with the crankcase 2. Since the reinforcing rib 16 provides, on the outer periphery of the crankcase 2, mutual connection between the plurality of steps 8, which are inside the reinforcing rib 16, the rigidity with which the bearing bracket 10 is supported by these steps 8 and, consequently, the rigidity with which the crankshaft 12 is supported by the bearing bracket 10, can be increased effectively. As a result, the crankcase 2 can be made thin and light. In particular, since an end part of the reinforcing rib 16 is connected integrally to the outside wall of the cylinder block 3, the reinforcing function of the reinforcing rib 16 can be enhanced, thus further increasing the rigidity with which the bearing bracket 10 is supported. A side cover 17 is joined to the crankcase 2 via a plurality of bolts 24 to close the open face on said one side of the crankcase 2. One end part of the crankshaft 12 runs through the side cover 17 and projects outward as an output shaft part, and an oil seal 18 is mounted on the side cover 17 to be in intimate contact with the outer periphery of the output shaft part. Referring again to FIG. 1, the other endpart of the crankshaft 12 runs through said other side wall of the crankcase 2, and an oil seal 19 is mounted on said other side wall of the crankcase 2 to be in intimate contact with said other end part of the crankshaft 12 so as to be adjacent to the outside of the bearing 13′. A flywheel 21, which also functions as a rotor of a generator 20, is secured to said other end part of the crankshaft 12, and a cooling fan 22 is attached to an outside face of the flywheel 21. Furthermore, a recoil-type starter 23, which is supported on the crankcase 2, is disposed so as to face said other end part of the crankshaft 12. In FIG. 1 and FIG. 3, a piston 25 fitted into the cylinder bore 3a is connected to the crankshaft 12 via a connecting rod 26. A combustion chamber 27 communicating with the cylinder bore 3a, and an intake port 28i and an exhaust port 28e each opening in the combustion chamber 27 are formed in the cylinder head 5. An intake valve 29i and an exhaust valve 29e are mounted in the cylinder head 5 for opening and closing the ends of the intake and exhaust ports 28i and 28e respectively that open to the combustion chamber 27. Valve springs 30i and 30e are fitted onto the intake and exhaust valves 29i and 29e to urge these valves 29i and 29e in a direction in which they close. The intake and exhaust valves 29i and 29e are opened and closed by a valve operating system 35 operating in cooperation with these valve springs 30i and 30e. The valve operating system 35 is described by reference to FIG. 3, FIG. 4, and FIG. 6 to FIG. 12. Referring first to FIG. 3, FIG. 4, and FIG. 6, the valve operating system 35 comprises a camshaft 36, a timing transmission system 37, an intake rocker arm 38i, and an exhaust rocker arm 38e. The camshaft 36 is supported on the cylinder head 5 so as to be parallel to the crankshaft 12, and includes an intake cam 36i and an exhaust cam 36e. The timing transmission system 37 provides a connection between the crankshaft 12 and the camshaft 36. The intake rocker arm 38i provides an operative connection between the intake cam 36i and the intake valve 29i. The exhaust rocker arm 38e provides an operative connection between the exhaust cam 36e and the exhaust valve 29e. The camshaft 36 has opposite end parts supported by a pouch-shaped bearing hole 39 and a ball bearing 41, the bearing hole 39 being formed in one side wall 5a of the cylinder head 5, and the ball bearing 41 being fitted into a bearing fitting hole 40 of a dividing wall 5b in a middle section of the cylinder head 5. One common rocker shaft 42 swingably supporting the intake and exhaust rocker arms 38i and 38e has opposite end parts supported by first and second support holes 43′ and 43 formed in said one side wall 5a and the dividing wall 5b, respectively. The first support hole 43′ of said one side wall 5a is pouch-shaped, and the second support 43 of the dividing wall 5b is a through hole. A fixing bolt 44 having its extremity abutting against the outer end of the rocker shaft 42 is screwed into the dividing wall 5b at an outer end part of the second support hole 43. The rocker shaft 42 is thus prevented from moving in a thrust direction by the pouch-shaped first support hole 43′ and the fixing bolt 44. The fixing bolt 44 has on its head part an integral flange seat 44a having a relatively large diameter, the flange seat 44a abutting against an outer end face of an outer race 41a of the ball bearing 41 supporting the camshaft 36. An inner race 41b of the ball bearing 41 is press-fitted onto the camshaft 36. Thus, when the flange seat 44a of the fixing bolt 44 abuts against the outer end of the outer race 41a as described above, the camshaft 36 is prevented from moving in a thrust direction by the pouch-shaped bearing hole 39 and the flange seat 44a. Therefore, it is possible to prevent movement in the thrust direction for both the rocker shaft 42 and the camshaft 36 by means of one fixing bolt 44, thus reducing the number of components of the valve operating system 35, simplifying the structure thereof, contributing to making it compact, and contributing to an improvement in the assemblability of the system 35. The timing transmission system 37 comprises a toothed drive pulley 45 secured to the crankshaft 12, a toothed driven pulley 46 secured to the camshaft 36, and an endless timing belt 47 wound around the drive and driven pulleys 45 and 46, the number of teeth of the driven pulley 46 being twice of that of the drive pulley 45. Rotation of the crankshaft 12 is therefore reduced by ½ by this timing transmission system 37, and transmitted to the camshaft 36. Due to rotation of the camshaft 36, the intake and exhaust cams 36i and 36e make the intake and exhaust rocker arms 38i and 38e swing against the urging forces of the valve springs 30i and 30e respectively, thereby opening and closing the intake and exhaust valves 29i and 29e. This timing transmission system 37 is housed in a timing transmission chamber 48 formed by connecting in sequence a lower chamber 48a, a middle chamber 48b, and an upper chamber 48c, the lower chamber 48a being defined between the bearing bracket 10 and the side cover 17, the middle chamber 48b being formed in the cylinder block 3 on one side of the cylinder bore 3a, and the upper chamber 48c being formed on one side of the cylinder head 5. That is, the drive pulley 45 is disposed in the lower chamber 48a, the driven pulley 46 is disposed in the upper chamber 48c, and the timing belt 47 is disposed so as to run through the middle chamber 48b. In this way, the space between the bearing bracket 10 and the side cover 17 is utilized effectively for arranging the timing transmission system 37, thereby making the engine E compact. A valve operating chamber 49 having an open upper face is formed in the cylinder head 5 between said one side wall 5a and the dividing wall 5b, and the intake and exhaust cams 36i and 36e of the camshaft 36 and the intake and exhaust rocker arms 38i and 38e, etc. are housed in the valve operating chamber 49. The open upper face of the valve operating chamber 49 is closed by a head cover 52 joined to the cylinder head 5 via a bolt 53. The upper chamber 48c of the timing transmission chamber 48 and the valve operating chamber 49 communicate with each other via an oil passage hole 75 (see FIG. 8 and FIG. 11) provided in the dividing wall 5b and a plurality of oil passage channels 76 (see FIG. 6 and FIG. 11) provided on an inner peripheral face of the bearing fitting hole 40. In FIG. 6 to FIG. 9, an access window 55 is provided on an outer end face 5c of the cylinder head 5, the access window 55 opening the upper chamber 48c so that the outer side face of the driven pulley 46 faces the access window 55. The access window 55 is used for inserting the driven pulley 46 within the timing belt 47, and mounting the driven pulley 46 on the camshaft 36. A lid body 57 closing the access window 55 is joined to the outer end face 5c via a seal 56 by means of a plurality of bolts 58. As clearly shown in FIG. 6, the outer end face 5c of the cylinder head 5, to which the lid body 57 is joined, comprises an inclined face 5c that is inclined so that at least part of the outer periphery of the driven pulley 46 on the side opposite to the drive pulley 45 is exposed through the access window 55, and preferably at least half the periphery of the driven pulley 46 on the side opposite to the drive pulley 45 is exposed through the access window 55. The structure with which the driven pulley 46 is mounted on the camshaft 36 is now described. As shown in FIG. 6, the driven pulley 46 comprises a bottomed cylindrical hub 46a, a web 46b that widens radially from the hub 46a, and a toothed rim 46c formed on the outer periphery of the web 46b. The hub 46a is fitted onto the outer periphery of an outer end part of the camshaft 36 projecting toward the upper chamber 48c side. An end wall of the hub 46a is provided with a bolt hole 60 positioned eccentrically to the center of the hub 46a, and a positioning groove 61 extending from one side of the bolt hole 60 to the side exactly opposite to the direction of the eccentricity. Furthermore, a first match mark 62a is cut into an outer side face of the rim 46c, and a second match mark 62b corresponding to the first match mark 62a is cut into the outer end face 5c of the cylinder head 5. Moreover, the web 46b is provided with a plurality of through holes 64, 64 that penetrate it. The outer end part of the camshaft 36 is provided, as shown in FIG. 6 and FIG. 11, with a threaded hole 66 corresponding to the bolt hole 60 and a positioning pin 67 corresponding to the positioning groove 61. When the crankshaft 12 is at a predetermined rotational position corresponding to a specified position (for example, top dead center) of the piston 25, and the camshaft 36 is at a position in a predetermined phase relationship with respect to the crankshaft 12, the first match mark 62a and the second match mark 62b, the bolt hole 60 and the threaded hole 66, and the positioning groove 61 and the positioning pin 67 each coincide with each other on a straight line L running through the centers of the two shafts 12 and 36. When the driven pulley 46 is mounted on the camshaft 36, the crankshaft 12 is first fixed at the rotational position corresponding to the specified position of the piston 25. Subsequently, as shown in FIG. 12(A), the driven pulley 46 is put inside the timing belt 47, which has been wound around the drive pulley 45 in advance, while making the first match mark 62a of the rim 46c match the second match mark 62b of the cylinder head 5. Next, as shown in FIG. 12(B), when the driven pulley 46 is moved together with the timing belt 47 so that the bolt hole 60 of the driven pulley 46 receives the positioning pin 67 of the camshaft 36 and the positioning pin 67 is then guided into the positioning groove 61, the camshaft 36 rotates in response thereto; and when the positioning pin 67 reaches the extremity of the positioning groove 61, as shown in FIG. 12(C), the bolt hole 60 and the threaded hole 66 match each other at the same time as the camshaft 36 and the hub 46a are coaxially aligned. In this way, by the remarkably simple operation of guiding the positioning pin 67 received by the bolt hole 60 to the positioning groove 61, the first and second match marks 62a and 62b, the bolt hole 60 and the threaded hole 66, and the positioning groove 61 and the positioning pin 67 are all aligned on the straight line L running through the centers of the crankshaft 12 and the camshaft 36. By visually checking this state, it can easily be confirmed that the crankshaft 12 and the camshaft 36 are in the predetermined phase relationship. As shown in FIG. 6, screwing and tightening the mounting bolt 68 into the threaded hole 66 through the bolt hole 60 enables the hub 46a to be fixed to the camshaft 36. In this way, the timing transmission system 37 is mounted on the crankshaft 12 and the camshaft 36, which are mounted on the crankcase 2 and the cylinder head 5 in advance, in the predetermined phase relationship. In this case, since the bolt hole 60 and the threaded hole 66 are positioned eccentrically to the centers of the hub 46a and the camshaft 36 respectively, rotation of the driven pulley 46 can be transmitted reliably to the camshaft 36 via one eccentric mounting bolt 68, and it is also possible to prevent the mounting bolt 68 from loosening. Furthermore, since the threaded hole 66 and the positioning pin 67 are positioned eccentrically, in mutually opposite directions, to the center of the camshaft 36, a sufficient degree of eccentricity can be given to each of the bolt hole 60 and the positioning groove 61, which are formed in a narrow end wall of the hub 46a of the driven pulley 46, thereby enhancing the positioning effect of the positioning groove 61 relative to the positioning pin and the torque capacity of the mounting bolt 68. As described above, since the outer end face of the cylinder head 5 on which the access window 55 opens is the inclined face 5c, and part of the outer periphery of the driven pulley 46 is exposed through the access window 55, the part of the driven pulley 46 exposed outside the access window 55 can easily be held by a tool, etc. without interference by the cylinder head 5, thereby facilitating the mounting of the driven pulley 46 on the camshaft 36 and the removal thereof. Therefore, this contributes to an improvement in the assemblability and the ease of maintenance. A side wall 73 of the lid body 57 joined to the outer end face 5c of the cylinder head 5, that is, the inclined face 5c, is formed so as to be inclined along the inclined face 5c. With this arrangement, a head part of the engine main body 1 is shaped such that its lateral width narrows toward the extremity side, thus making the engine E compact. As shown in FIG. 7 to FIG. 9, a pair of projecting parts 70 and 70 projecting outwardly of the access window 55 beneath the access window 55 are formed on the cylinder head 5; these projecting parts 70 and 70 are superimposed on an upper end face, on the outside of the middle chamber 48b, of the cylinder block 3 via the gasket 4, and secured to the cylinder block 3 via the auxiliary connecting bolts 7 and 7. In accordance with such securing by the auxiliary connecting bolts 7 and 7, it is possible to adequately increase the surface pressure acting on the gasket 4 from the cylinder block 3 and the cylinder head 5 even outside the middle chamber 48b housing the timing belt 47. Moreover, since the presence of the inclined face 5c secures a sufficient space above the auxiliary connecting bolts 7 and 7, for receiving a tool for operating the auxiliary connecting bolts 7 and 7, tightening of the auxiliary connecting bolts 7 and 7 can easily be carried out. This means that the extent to which the projecting parts 70 and 70 project outwardly of the access window 55 can be made small, and this also contributes to making the engine E compact. Tightening the auxiliary connecting bolts 7 and 7 is carried out prior to the lid body 57 being mounted. Lubrication of the valve operating system 35 is now described. In FIG. 1 to FIG. 3, FIG. 6, and FIG. 8, the lower chamber 48a of the timing transmission chamber 48 communicates with the interior of the crankcase 2, that is, the crank chamber 9, through the plurality of steps 8 on the inner wall of the crankcase 2 supporting the bearing bracket 10, and a predetermined amount of lubricating oil 71 that is common to the crank chamber 9 and the lower chamber 48a accumulates in these chambers. As shown in FIG. 3, an impeller type oil slinger 72 is disposed in the lower chamber 48a so that part of the oil slinger 72 is submerged in the oil 71 that accumulates in the lower chamber 48a. The oil slinger 72 is driven by the crankshaft 12 via gears 74 and 74′. This oil slinger 72 scatters the oil 71 around by its rotation, and an oil guide wall 73 for guiding the scattered oil to the timing belt 47, side is formed integrally with an outer side face of the bearing bracket 10 so as to surround the oil slinger 72 and the periphery of the timing belt 47 on the drive pulley 45 side. Since the bearing bracket 10 is a relatively small component, this can easily be cast together with the oil guide wall 73. Further, since the bearing bracket 10 integrally has the oil guide wall 73, its rigidity is strengthened and this is also effective in enhancing the rigidity with which the crankshaft 12 is supported. In the lower chamber 48a, oil scattered by the oil slinger 72 is guided by the oil guide wall 73 to the timing belt 47 side; the oil that has been deposited on the timing belt 47 is transferred to the upper chamber 48c by the belt 47; scattered around by being shaken off due to centrifugal force when the timing belt 47 becomes wound around the driven pulley 46; and made to collide with the surrounding wall to thus form an oil mist; and the upper chamber 48c is filled with this oil mist, thereby lubricating not only the entire timing transmission system 37 but also the ball bearing 41 of the camshaft 36. In particular, in the upper chamber 48c, when part of the oil shaken off the timing belt 47 collides with the inclined inner face of the lid body 57, it bounces off toward the web 46b of the driven pulley 46. This oil passes through the through holes 64 and 64 of the driven pulley 46, and is scattered over the ball bearing 41, thus lubricating the ball bearing 41. Part of the oil scattered over the ball bearing 41 moves to the valve operating chamber 49 through the oil passage channel 76 on the outer periphery of the bearing 41, and the ball bearing 41 is therefore lubricated also from the valve operating chamber 49 side. Lubrication of the ball bearing 41 is thus carried out very well. As shown in FIG. 3, a base part of the valve operating chamber 49 communicates with the crank chamber 9 via a series of oil return passages 77 formed in the cylinder head 5 and the cylinder block 3 along one side of the cylinder bore 3a. The oil return passage 77 is inclined downward toward the crank chamber 9 so that oil flows down from the valve operating chamber 49 to the crank chamber 9. While the engine E is running, pressure pulsations occur in the crank chamber accompanying the rise and fall of the piston 25, and when the pressure pulsations are transmitted to the valve operating chamber 49 and the timing transmission chamber 48 through the oil return passage 77, the oil passage hole 75 and the oil passage channel 76, oil mist moves to and fro between the valve operating chamber 49 and the timing transmission chamber 48, thereby effectively lubricating the entire valve operating system 35. After lubrication, oil that has collected in the valve operating chamber 49 flows down the oil return passage 77 and returns to the crank chamber 9. Furthermore, since the base face of the timing transmission chamber 48 is inclined downward toward the lower chamber 48a, oil that has collected in the upper chamber 48c flows down the middle chamber 48b and returns to the lower chamber 48a. In this way, by utilizing the operation of the oil slinger 72 and the timing transmission system 37 and the pressure pulsations of the crank chamber 9, the interiors of the timing transmission chamber 48 and the valve operating chamber 49, which are separated from each other, can be lubricated with oil mist. Therefore, it is unnecessary to employ an oil pump exclusively used for lubrication, whereby structure of the engine E can be simplified and made compact, and the cost can be reduced. Further, it is possible to maintain the arrangement in which the camshaft 36 is disposed above the intake and exhaust valves 29i and 29e, thereby ensuring a desired output performance for the engine. The present invention is not limited to the above-mentioned embodiment, and may be modified in a variety of ways as long as the modifications do not depart from the spirit and scope thereof. For example, the belt type timing transmission system 37 may be replaced with a chain type.
|
F
|
F01
|
F01L
|
1
|
02
|
|||
11712007
|
US20070200288A1-20070830
|
Sheet feed tray and image forming apparatus
|
ACCEPTED
|
20070816
|
20070830
|
[]
|
B65H3136
|
["B65H3136"]
|
7770886
|
20070228
|
20100810
|
271
|
171000
|
79978.0
|
MCCULLOUGH
|
MICHAEL
|
[{"inventor_name_last": "Yoshiuchi", "inventor_name_first": "Katsuhiro", "inventor_city": "Osaka-shi", "inventor_state": "", "inventor_country": "JP"}]
|
A sheet feed tray has a bottom plate on which a sheet is to be placed; two side fences for positioning opposite widthwise sides of a sheet placed on the bottom plate; and an interlocking mechanism for interlocking movements of the side fences toward and away from each other. The interlocking mechanism includes two racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate. The pinion is rotatable about its central axis and is engageable with the pair of racks. Locking projections are disposed at the respective rack sides and project toward the bottom plate side. Contact portions are disposed at the bottom plate side and engage the locking projections with the pair of side fences maximally or minimally spaced apart from each other.
|
1. A sheet feed tray, comprising: a bottom plate on which a sheet is to be placed; a pair of side fences for positioning the opposite widthwise sides of a sheet placed on the bottom plate; an interlocking mechanism for interlocking movements of the pair of side fences in directions toward and away from each other, the interlocking mechanism including a pair of racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate rotatably about its central axis thereof and engageable with the pair of racks; locking projections disposed at the respective rack sides and projecting toward the bottom plate side; and contact portions disposed at the bottom plate side and engageable with the locking projections with the pair of side fences maximally or minimally spaced apart from each other. 2. A sheet feed tray according to claim 1, wherein: the bottom plate is recessed to form a recessed groove which extends in moving directions of the side fences and into which the locking projections are fittable, and the contact portions are end walls formed at ends of the recessed groove. 3. A sheet feed tray according to claim 1, wherein the contact portions are bottom-plate side locking projections projecting from the bottom plate in correspondence with the locking projections. 4. A sheet feed tray, comprising: a bottom plate on which a sheet is to be placed; a pair of side fences for positioning the opposite widthwise sides of a sheet placed on the bottom plate; an interlocking mechanism for interlocking movements of the pair of side fences in directions toward and away from each other, the interlocking mechanism including a pair of racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate rotatably about its central axis thereof and engageable with the pair of racks; locking projections disposed at the bottom plate side and projecting toward the rack sides; and contact portions disposed at the respective rack sides and engageable with the locking projections with the pair of side fences maximally or minimally spaced apart from each other. 5. An image forming apparatus, comprising: an apparatus main body for applying an image forming process to a sheet; a sheet feeder attached to the apparatus main body to feed a sheet or a document to be read toward a specified position of the apparatus main body; and a sheet feed tray provided in the sheet feeder and adapted to bear the sheet or the document, wherein the sheet feed tray includes: a bottom plate on which a sheet is to be placed; a pair of side fences for positioning the opposite widthwise sides of a sheet placed on the bottom plate; an interlocking mechanism for interlocking movements of the pair of side fences in directions toward and away from each other, the interlocking mechanism including a pair of racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate rotatably about its central axis thereof and engageable with the pair of racks; locking projections disposed at the respective rack side and projecting toward the bottom plate side; and contact portions disposed at the bottom plate side and engageable with the locking projections with the pair of side fences maximally or minimally spaced apart from each other. 6. An image forming apparatus according to claim 5, wherein: the bottom plate is recessed to form a recessed groove which extends in moving directions of the side fences and into which the locking projections are fittable, and the contact portions are end walls formed at ends of the recessed groove. 7. An image forming apparatus according to claim 5, wherein the contact portions are bottom-plate side locking projections projecting from the bottom plate in correspondence with the locking projections. 8. An image forming apparatus, comprising: an apparatus main body for applying an image forming process to a sheet; a sheet feeder attached to the apparatus main body to feed a sheet or a document to be read toward a specified position of the apparatus main body; and a sheet feed tray provided in the sheet feeder and adapted to bear the sheet or the document, wherein the sheet feed tray includes: a bottom plate on which a sheet is to be placed; a pair of side fences for positioning the opposite widthwise sides of a sheet placed on the bottom plate; an interlocking mechanism for interlocking movements of the pair of side fences in directions toward and away from each other, the interlocking mechanism including a pair of racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate rotatably about its central axis thereof and engageable with the pair of racks; locking projections disposed at the bottom plate side and projecting toward the rack sides; and contact portions disposed at the respective rack side and engageable with the locking projections the pair of side fences maximally or minimally spaced apart from each other.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a sheet feed tray to have sheets placed thereon and an image forming apparatus to which this sheet feed tray is applied. 2. Description of the Background Art There has been conventionally known a sheet feed tray to have a stack of sheets placed thereon in order to feed sheets to an image forming apparatus as disclosed in Japanese Unexamined Patent Publication No. H09-272635 (hereinafter, document 1) or Japanese Unexamined Patent Publication No. 2002-240964 (hereinafter, document 2). Such a sheet feed tray includes a pair of side fences opposed to each other in widthwise direction normal to the conveyance direction of sheets and extending in the conveyance direction, a pair of racks fixed to the corresponding side fences, extending in width direction and having toothed surfaces opposed to each other, and a pinion interposed between the respective racks in such a manner as to be engaged with the teeth of the respective racks. In this construction, one side fence is moved in width direction, whereby this movement is transmitted to the other side fence via one rack, the pinion and the other rack, with the result that the other side fence is moved by the same amount in opposite direction. The pair of side fences needs to be accurately positioned relative to each other beforehand in order to feed sheets held therebetween to a specified position in the image forming apparatus in such a state as not to be displaced in sheet width direction. Accordingly, in the sheet feed tray of document 1, the respective side fences are engaged with the pinion while being stopped by stoppers or outer stoppers transversely symmetrically disposed with respect to the pinion in order to be accurately positioned at the time of assembling the sheet feed tray. Thus, the respective side fences are accurately positioned relative to each other. Contrary to this, in the sheet feed tray of document 2, positioning index are provided at one side of the pair of racks integral to the respective side fences and at one side of the pinion engaged with the respective racks, whereas applicable range marks corresponding to these index are provided on the other sides, and the index are caused to conform to the applicable range marks upon assembling the racks and the pinion into the sheet feed tray. Thus, the respective side fences are arranged at proper positions on the sheet feed tray. However, in the sheet feed tray of document 1, the positional relationship of the side fences may deviate from the proper one since the side fences are merely stopped by the inner or outer stoppers. Further, in the sheet feed tray of document 2, the positions of the index vary within a range defined by the applicable range marks even if the index are positioned within range defined by the applicable range marks. Therefore, there still exists a problem that the respective side fences cannot be accurately positioned.
|
<SOH> SUMMARY OF THE INVENTION <EOH>An object of the present invention is to provide a sheet feed tray in which a pair of side fences can be easily and securely positioned at the time of assembling a pinion and a pair of racks, and an image forming apparatus to which this sheet feed tray is applied. In order to accomplish this object, one aspect of the present invention is directed to a sheet feed tray, comprising a bottom plate on which a sheet is to be placed; a pair of side fences for positioning the opposite widthwise sides of a sheet placed on the bottom plate; an interlocking mechanism for interlocking movements of the pair of side fences in directions toward and away from each other, the interlocking mechanism including a pair of racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate rotatably about its central axis thereof and engageable with the pair of racks; locking projections disposed at the respective rack sides and projecting toward the bottom plate side; and contact portions disposed at the bottom plate side and engageable with the locking projections with the pair of side fences maximally or minimally spaced apart from each other. Another aspect of the present invention is directed to an image forming apparatus, comprising an apparatus main body for applying an image forming process to a sheet; a sheet feeder attached to the apparatus main body to feed a sheet or a document to be read toward a specified position of the apparatus main body; and a sheet feed tray provided in the sheet feeder, adapted to bear the sheet or the document and having the inventive construction. BRFSUM description="Brief Summary" end="tail"?
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feed tray to have sheets placed thereon and an image forming apparatus to which this sheet feed tray is applied. 2. Description of the Background Art There has been conventionally known a sheet feed tray to have a stack of sheets placed thereon in order to feed sheets to an image forming apparatus as disclosed in Japanese Unexamined Patent Publication No. H09-272635 (hereinafter, document 1) or Japanese Unexamined Patent Publication No. 2002-240964 (hereinafter, document 2). Such a sheet feed tray includes a pair of side fences opposed to each other in widthwise direction normal to the conveyance direction of sheets and extending in the conveyance direction, a pair of racks fixed to the corresponding side fences, extending in width direction and having toothed surfaces opposed to each other, and a pinion interposed between the respective racks in such a manner as to be engaged with the teeth of the respective racks. In this construction, one side fence is moved in width direction, whereby this movement is transmitted to the other side fence via one rack, the pinion and the other rack, with the result that the other side fence is moved by the same amount in opposite direction. The pair of side fences needs to be accurately positioned relative to each other beforehand in order to feed sheets held therebetween to a specified position in the image forming apparatus in such a state as not to be displaced in sheet width direction. Accordingly, in the sheet feed tray of document 1, the respective side fences are engaged with the pinion while being stopped by stoppers or outer stoppers transversely symmetrically disposed with respect to the pinion in order to be accurately positioned at the time of assembling the sheet feed tray. Thus, the respective side fences are accurately positioned relative to each other. Contrary to this, in the sheet feed tray of document 2, positioning index are provided at one side of the pair of racks integral to the respective side fences and at one side of the pinion engaged with the respective racks, whereas applicable range marks corresponding to these index are provided on the other sides, and the index are caused to conform to the applicable range marks upon assembling the racks and the pinion into the sheet feed tray. Thus, the respective side fences are arranged at proper positions on the sheet feed tray. However, in the sheet feed tray of document 1, the positional relationship of the side fences may deviate from the proper one since the side fences are merely stopped by the inner or outer stoppers. Further, in the sheet feed tray of document 2, the positions of the index vary within a range defined by the applicable range marks even if the index are positioned within range defined by the applicable range marks. Therefore, there still exists a problem that the respective side fences cannot be accurately positioned. SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feed tray in which a pair of side fences can be easily and securely positioned at the time of assembling a pinion and a pair of racks, and an image forming apparatus to which this sheet feed tray is applied. In order to accomplish this object, one aspect of the present invention is directed to a sheet feed tray, comprising a bottom plate on which a sheet is to be placed; a pair of side fences for positioning the opposite widthwise sides of a sheet placed on the bottom plate; an interlocking mechanism for interlocking movements of the pair of side fences in directions toward and away from each other, the interlocking mechanism including a pair of racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate rotatably about its central axis thereof and engageable with the pair of racks; locking projections disposed at the respective rack sides and projecting toward the bottom plate side; and contact portions disposed at the bottom plate side and engageable with the locking projections with the pair of side fences maximally or minimally spaced apart from each other. Another aspect of the present invention is directed to an image forming apparatus, comprising an apparatus main body for applying an image forming process to a sheet; a sheet feeder attached to the apparatus main body to feed a sheet or a document to be read toward a specified position of the apparatus main body; and a sheet feed tray provided in the sheet feeder, adapted to bear the sheet or the document and having the inventive construction. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing one example of a sheet feeder to which a sheet feed tray according to one embodiment of the invention is applied. FIG. 2 is an exploded perspective view partly cut away showing one embodiment of a side-fence retaining member. FIG. 3 is an assembled perspective view of the side-fence retaining member shown in FIG. 2. FIG. 4 is a perspective view of the side-fence retaining member shown in FIG. 3 when viewed from below. FIG. 5 is a section along V-V of the side-fence retaining member shown in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view showing one example of a sheet feeder 20 to which a sheet feed tray 30 according to one embodiment is applied. It should be noted that, in FIG. 1, X-X directions and Y-Y directions are respectively referred to as transverse directions and forward and backward directions, wherein, particularly, −X direction is leftward direction, +X direction rightward direction, −Y direction forward direction and +Y direction backward direction. As shown in FIG. 1, the sheet feeder 20 is applied as a component of a copier 10 as one type of an image forming apparatus. The copier 10 is provided with an apparatus main body 11 in which various members for image formation are mounted, and the sheet feeder 20 arranged atop this apparatus main body 11. An image of a document (sheet) P fed by the sheet feeder 20 is read by an unillustrated optical member disposed at a top part of the apparatus main body 11. A specified image forming process is performed in an unillustrated image forming unit based on the read image, and a transfer sheet stored in an unillustrated transfer sheet storing unit is fed to the image forming unit, whereby an image based on the image forming process is transferred to the transfer sheet. The sheet feeder 20 includes a cover member 21 having a rectangular plan view and adapted to cover the upper surface of the apparatus main body 11, an image reader 22 bulging upward at a substantially left half of the cover member 21, and the sheet feed tray 30 mounted in the image reader 22 in such a state as to project to right from the right end surface of this image reader 22. The rear bottom edge of the sheet feeder 20 is coupled to the top part of the apparatus main body 11 via unillustrated hinge members. The sheet feeder 20 is turned back and forth about these hinge members, thereby being displaceable between a closing posture to close the top part of the apparatus main body 11 and an opening posture to open this top part. An unillustrated contact glass is fitted in the top part of the apparatus main body 11. Upon reading an image, for example, from a book document, the sheet feeder 20 (cover member 21) is opened once to place the document on the contact glass and, successively, a document surface of the document placed on the contact glass is read with the cover member 21 closed. The sheet feed tray 30 is mounted on the upper part of the right surface of the image reader 22. A sheet feed opening 23 through which the document P is fed into the image reader 22 is defined between the upper surface of the left side of the sheet feed tray 30 and a ceiling plate 221 of the image reader 22. A sheet discharge tray 25 for receiving the document P having the image read by the image reader 22 is formed on the upper surface of the cover member 21 right below the sheet feed tray 30. A sheet discharge opening 24 is formed at a position of the right surface of the image reader 22 below the sheet feed tray 30. The document P having the image read is discharged to the sheet discharge tray 25 through this sheet discharge opening 24. The sheet feed tray 30 includes a tray main body 31 L-shaped in plan view, and a side-fence retaining member 40 provided at the left side of the tray main body 31 and elongated in forward and backward directions. A front right corner portion of the tray main body 31 is cut out to form a hook-shaped cutout portion 311, whereby the tray main body 31 is L-shaped in plan view. By forming the cutout portion 311, a user can easily place the document P holding in hand on the sheet feed tray 30 and remove it from the sheet feed tray 30. The tray main body 31 includes a leading-side tray main body 32 having a width thereof in forward and backward directions shortened by forming the cutout portion 311, and a base-side tray main body 33 located at the left side of the leading-side tray main body 32 and having a longer width in forward and backward directions than the leading-side tray main body 32. The width of the base-side tray main body 33 in forward and backward directions is set slightly shorter than that of the sheet feed opening 23. The sheet feed tray 30 is mounted into the image reader 22 by fitting the base-side tray main body 33 into the sheet feed opening 23. The base-side tray main body 33 is formed with a mounting recess 34 which is flat and has a rectangular plan view longer in forward and backward directions and into which the side-fence retaining member 40 is fittable. The depth of this mounting recess 34 is set such that the upper surface of the side-fence retaining member 40 fitted in the mounting recess 34 is flush with the upper surface of the tray main body 31. The side-fence retaining member 40 can be stably mounted in the tray main body 31 by being fitted into the mounting recess 34. With a bottom plate 41 fitted in the mounting recess 34, small clearances are defined between the left and right edges of the mounting recess 34 and those of the bottom plate 41. Thus, parts of supporting members 60 to be described in detail later are movable in forward and backward directions through these clearances. FIG. 2 is an exploded perspective view partly cut away showing one embodiment of the side-fence retaining member 40, FIG. 3 is an assembled perspective view of this side-fence retaining member 40, FIG. 4 is a perspective view showing the side-fence retaining member 40 shown in FIG. 3 when viewed from below and FIG. 5 is a section along V-V of the side-fence retaining member 40 shown in FIG. 3. It should be noted that directions indicated by X and Y in FIGS. 2 to 5 are similar to the case of FIG. 1 (X are transverse directions (−X: leftward direction, +X: rightward direction) and Y are forward and backward directions (−Y: forward direction, +Y: backward direction)). As shown in FIG. 2, the side-fence retaining member 40 includes the bottom plate 41, side fence members 50, the supporting members 60, racks 70 and a pinion member 80. Documents P are placed on the bottom plate 41. A pair of front and rear side fence members 50 are so mounted on the bottom plate 41 as to be movable in forward and backward directions. A pair of front and rear supporting members 60 are arranged at the underside of the bottom plate 41 such that the pair of side fence members 50 can be so supported as not to be detached from the bottom plate 41. A pair of front and rear racks 70 are fixed to the corresponding supporting members 60 at the underside of the bottom plate 41. The pinion member 80 is mounted in the middle of the underside of the bottom plate 41 while being engaged with the pair of racks 70. The size of the bottom plate 41 in plan view is so set as to be fittable into the mounting recess 34 of the tray main body 31 (see FIG. 1). A pair of guide rails 42 parallel to each other are so arranged at the underside of the bottom plate 41 as to extend over the entire length in forward and backward directions while being spaced apart in transverse direction by a specified distance. Further, a through hole 43 through which a pinion shaft 84 is inserted to attach the pinion member 80 to the bottom plate 41 is formed in the middle of the bottom plate 41. This through hole 43 is comprised of a small-diameter hole 431 and a large-diameter hole 432 formed concentrically with the small-diameter hole 431 in the upper surface of the bottom plate 41 and having a larger diameter than the small-diameter hole 431. A recessed groove 44 extending in forward and backward directions is formed at a transverse middle position of the underside of the bottom plate 41. This recessed groove 44 extends forward and backward by the same distance from the center of the bottom plate 41 with respect to forward and backward directions (specifically, from the center of the through hole 43). End walls (contact portions) 441 for hindering the side fence members 50 from moving any further outward are formed at the front and rear ends of such a recessed groove 44. Accordingly, the pair of side fence members 50 are maximally spaced apart with outward movements of both front and rear side fence members 50 hindered by the end walls 441. In addition, hooks 45 each having a locking claw projecting outward project downward at middle positions of the left and right edges of the bottom plate 41 with respect to forward and backward directions. These hooks 45 are engaged with unillustrated locking holes formed at the corresponding edges of the mounting recess 34 by fitting the bottom plate 41 into the mounting recess 34 (see FIG. 1) of the tray main body 31. In this way, the detachment of the bottom plate 41 from the mounting recess 34 can be prevented. The pair of side fence members 50 are for holding the document P placed on the bottom plate 41 therebetween and guiding the document P to the image reader 22 while preventing displacements of the document P in width direction. The respective side fence members 50 are a front side fence member 501 and a rear side fence member 502 that are arranged in mirror-image symmetry with respect to forward and backward directions. Since the front and rear side fence members 501, 502 are identically constructed except that they are in mirror-image symmetry, components thereof are identified by the same reference numerals in the following description. Each of the front and rear side fence members 501, 502 includes a fence supporting plate 51 to be slidably placed in close contact with the upper surface of the bottom plate 41, having a substantially rectangular plan view and elongated in transverse direction, and a side fence 52 standing on the fence supporting plate 51 and extending in transverse direction. The length of the fence supporting plate 51 in transverse direction is set slightly longer than the width of the bottom plate 41 in transverse direction. Thus, the fence supporting plate 51 bulges out to the left and right from the bottom plate 41 while being placed on the bottom plate 41. The side fences 52 are for holding the document P placed on the bottom plate 41 in a pair. A substantially transverse middle part of each side fence 52 bulges upward and an arcuate edge portion extends obliquely downward to the left from the top of the bulged-out part along a concave curve, thereby making the side fence 52 excellent in design. The side fence 52 extends in transverse direction at a front position of the fence supporting plate 51 in the front side fence member 501 while extending in transverse direction at a back position of the fence supporting plate 51 in the rear side fence member 502. In each side fence member 50 constructed as above, through holes 53 are formed at four corners of the fence supporting plate 51. The side fence member 50 is mounted on the corresponding supporting member 60 by inserting screws B through the through holes 53 and spirally engaging the screws B with internally threaded holes 631 of the supporting member 60 to be described later. The supporting members 60 are for supporting the side fence members 50 placed on the bottom plate 41 lest the side fence members 50 should be detached from the bottom plate 41. Each supporting member 60 includes a bridging plate 61, sliding contact pieces 62 and connecting pieces 63. The bridging plate 61 is a member that is elongated in transverse direction and is mounted to span between the pair of guide rails 42 arranged on the underside of the bottom plate 41 and extending in forward and backward directions while being held in sliding contact therewith. The sliding contact pieces 62 are a pair of left and right members that are elongated in forward and backward directions and have the surfaces thereof facing each other held in sliding contact with the outer wall surfaces of the pair of guide rails 42. The sliding contact pieces 62 extend in opposite directions from the upper surfaces of the left and right ends of the respective bridging plates 61. The connecting pieces 63 are a pair of members that project upward from the corresponding sliding contact pieces 62 to slidably hold the bottom plate 41 therebetween and are used to mount the side fence members 50. A distance between the inner surfaces of the sliding contact pieces 62 is set slightly larger than a distance between the outer surfaces of the pair of guide rails 42. Thus, the supporting member 60 is movable in forward and backward directions while being guided by the guide rails 42 by engaging the pair of sliding contact pieces 62 with the pair of guide rails 42. The connecting pieces 63 are formed with the internally threaded holes 631 at positions facing the four through holes 53 formed in the fence supporting plate 51 of the side fence member 50. The side fence member 50 is mounted on the supporting member 60 by inserting the screws B through the respective through holes 53 and spirally engaging the screws B with the internally threaded holes 631 for tightening with the fence supporting plate 51 placed on the pair of connecting pieces 63. Each bridging plate 61 is formed with a rib 611 extending in forward and backward directions at a position slightly to the right from the transverse center with the supporting member 60 oriented such that the sliding contact pieces 62 extend forward from the bridging plate 61. A mounting recess 612 for fixing the corresponding rack 70 is formed between the rib 611 and the sliding contact piece 62 closer to the rib 611. On the other hand, a sliding contact recess 614 for receiving the mating rack 70 while being held in sliding contact therewith is formed between the rib 611 and the sliding contact piece more distant from the rib 611. Further, at a transverse middle position of the bridging plate 61, a locking projection 64 projects from the edge of the bridging plate 61 opposite to the one where the sliding contact pieces 62 project in a direction opposite to the projecting direction of the sliding contact pieces 62. The locking projection 64 is comprised of a tongue piece 641 projecting from the bridging plate 61 and a hooking piece 642 formed at the leading end of this tongue piece 641. A locking wall surface 642a projecting upward is formed at the base end of the hooking piece 642. Such a locking projection 64 is dimensioned such that the hooking piece 642 is fitted into the recessed groove 44 of the bottom plate 41 with the supporting member 60 attached to the bottom plate 41 as shown in FIG. 4. That “the locking projection is disposed at the rack side” is defined in a claim of the present application. A concept of the rack side is used as opposed to the bottom plate side. In other words, it means that the locking projection 64 is not provided at the side of the bottom plate 41, but at the side of the rack 70 facing the bottom plate 41. A mode in which the locking projection 64 is disposed at the supporting member 60 integral to the rack 70 as in this embodiment falls under “disposed at the rack side”. The thus constructed supporting members 60 having a completely identical shape are employed for the front and rear side fence members 501, 502, and are mounted on the front and rear side fence members 501, 502 while having the orientations thereof changed so that the respective locking projections 64 facing each other. Each rack 70 is elongated in forward and backward directions and includes a plurality of rack teeth (toothed surface) 71 formed at specified pitches at one of the edges thereof extending in longitudinal direction. The width of the rack 70 in transverse direction is set slightly smaller than that of the mounting recess 612 of the supporting member 60 so as to be fittable into the mounting recess 612. A through hole 72 is formed at the base end of the rack 70 where no rack teeth 71 are formed. On the other hand, an internally threaded hole 613 corresponding to the through hole 72 is formed at the bottom of the mounting recess 612. The rack 70 is mounted on the supporting member 60 by inserting a screw B into the through hole 72 with the base end of the rack 70 fitted in the mounting recess 612 and spirally engaging this screw B with the internally threaded hole 613 for tightening. The pinion member 80 is engaged with the pair of racks 70. The pinion member 80 includes a pinion 81 having a plurality of teeth formed at specified pitches on the outer circumferential surface thereof, and a flange 82 concentrically and integrally superimposed below the pinion 81 and having a diameter slightly larger than that of the pinion 81. An effective diameter of the pinion 81 is set such that the pinion 81 is engageable with the rack teeth of the pair of racks 70 facing each other at the underside of the bottom plate 41. Such a pinion member 80 is formed with a center hole 83 at its center position, and is attached to the underside of a central part of the bottom plate 41 by inserting a pinion shaft 84 passed through the through hole 43 into this center hole 83. On the other hand, the pinion shaft 84 includes a pinion-shaft main body 841 insertable into the small-diameter hole 431 of the through hole 43 formed in the bottom plate 41 while being held in sliding contact therewith, and a head portion 842 concentrically and integrally formed at the upper end of the pinion-shaft main body 841 and fittable into the large-diameter hole 432 of the through hole 43 while being held in sliding contact therewith. The pinion-shaft main body 841 has an internally threaded hole 843 concentrically formed in an end surface thereof opposite to the head portion 842. The pinion member 80 is mounted at a center position of the underside of the bottom plate 41 by spirally engaging a screw B with the internally threaded hole 843 for tightening with the center hole 83 thereof engaged with the pinion shaft 84 passed through the through hole 43. As described above, in this embodiment, the pair of racks 70 provided for the respective side fences 52 via the supporting members 60 and the pinion member 80 engaged with these racks 70 are employed as an interlocking mechanism for interlocking a movement of one side fence 52 with that of the other side fence 52. Next, the assembling of the side-fence retaining member 40 thus constructed is described. Upon assembling, two supporting members 60 and two racks 70 are first prepared. Subsequently, the base ends of the racks 70 are fitted in the mounting recesses 612 (see FIG. 2) formed on the bridging plates 61 of the respective supporting members 60 with the rack teeth 71 faced toward the locking projections 64, and then the screws B are inserted through the through holes 72 of the racks 70 and spirally engaged with the internally threaded holes 613 formed in the bottoms of the mounting recesses 612 for tightening. The thus obtained two supporting members 60 equipped with the racks 70 are respectively attached to the bottom plate 41. The supporting members 60 are attached to the bottom plate 41 by fitting the pairs of sliding contact pieces 62 formed in the respective supporting members 60 to the pair of guide rails 42. By fitting the pairs of sliding contact pieces 62 to the pair of guide rails 42, the bottom plate 41 is tightly held between the pairs of connecting pieces 63 of the supporting members 60. The side fence members 50 are placed on the top surface of the bottom plate 41 in this state to tightly hold the bottom plate 41 by the side fence members 50 and the supporting members 60. At this time, the hooking pieces 642 of the locking projections 64 disposed at the bridging plates 61 of the supporting members 60 are fitted into the recessed groove 44 of the bottom plate 41. Subsequently, the screws B are inserted through the respective through holes 53 formed at the four corners of each fence supporting plate 51 and spirally engaged with the internally threaded holes 631 formed in the respective connecting pieces 63 of each supporting member 60 for tightening, whereby the side fence members 50 and the supporting members 60 are attached to the bottom plate 41. The respective side fence members 50 are moved in directions away from each other with the pair of side fence members 50 and the pair of supporting members 60 attached to the bottom plate 41. In this way, the locking wall surfaces 642a of the hooking pieces 642 of the respective supporting members 60 come into contact with the front and rear end walls 441 of the recessed groove 44 of the bottom plate 41, i.e. the respective side fence members 50 are maximally spaced apart as shown in FIG. 5. In this state, the pinion shaft 84 is inserted through the through hole 43 of the bottom plate 41 from the top side, the center hole 83 of the pinion member 80 is fitted on the pinion-shaft main body 841 projecting from the underside of the bottom plate 41, and the pinion 81 is engaged with the rack teeth 71 of the respective racks 70 facing each other. Subsequently, the screw B is spirally engaged with the internally threaded hole 843 formed in the end surface of the pinion-shaft main body 841 for tightening. In this way, the pinion member 80 is attached to and retained at the central part of the underside of the bottom plate 41. The assembling of the side-fence retaining member 40 is thus completed. Immediately after the side-fence retaining member 40 is assembled, the pair of side fence members 50 are held maximally spaced apart and positioned symmetrically at the front and rear sides with respect to the center position of the bottom plate 41. Accordingly, if either one of the side fence members 50 is moved thereafter, the other side fence member 50 is moved by the same distance in an opposite direction via the rack 70 and the pinion member 80, wherefore the respective side fences 52 are constantly located at symmetrical positions. By fitting the side-fence retaining member 40 thus assembled into the mounting recess 34 of the tray main body 31, the pair of hooks 45 of the side-fence retaining member 40 are engaged with the opposite left and right edges of the mounting recess 34, whereby the sheet feed tray 30 as shown in FIG. 1 is completed. As described in detail above, the sheet feed tray 30 according to this embodiment includes the bottom plate 41 on which the document P is placed, the pair of side fences 52 for positioning the opposite sides of the document P placed on the bottom plate 41 and facing each other in width direction normal to a conveyance direction of the document P, and the interlocking mechanism for interlocking movements of the pair of side fences 52 in directions toward and away from each other. The interlocking mechanism is comprised of the pair of racks 70 integrally attached to the respective side fences 52 with the rack teeth 71 opposed to each other and movable while facing the bottom plate 41, and the pinion 81 attached to the bottom plate 41 rotatably about its central axis and engaged with the pair of racks 70. According to this construction, if one side fence 52 is moved in the width direction of a document P in conformity with the size of the document P upon placing the document P on the bottom plate 41 of the sheet feed tray 30, such a movement is transmitted to the other side fence 52 via one rack 70, the pinion 81 and the other rack 70. Thus, the other side fence 52 is moved by the same distance in a direction opposite to the one side fence 52. Therefore, both side fences 52 are positioned only by positioning one side fence 52, wherefore the side fences 52 can be easily positioned. The locking projection 64 projecting toward the bottom plate 41 is disposed at each rack 70, whereas the bottom plate 41 is formed with the recessed groove 44. Further, the recessed groove 44 has the end walls 441 to be held in contact with the locking projections 64 with the respective side fences 52 maximally spaced apart. Thus, the pair of side fences 52 is maximally spaced apart by engaging the locking projections 64 with the end walls 441 upon assembling the sheet feed tray 30, and can be properly positioned relative to each other by assembling the pinion 81 in such a manner as to be engaged with the respective racks 70 in this state. Therefore, the phase alignment of the side fences 52 (centering of a document P to be fed) can be easily and properly performed. Accordingly, the sheet feed tray 30 can be quickly and easily assembled with the pair of side fences 52 properly positioned without using a jig such as a scale. Thus, operability in assembling the side fences 52 can be remarkably improved and maintainability, for example, upon conducting a repair can also be improved. The bottom plate 41 is recessed to form the recessed groove 44 into which the locking projections 64 are fitted and which extend in the moving directions of the side fences 52 and are formed with the end walls 441 as the contact portions. Thus, by fitting the locking projections 64 into the recessed groove 44, the side fences 52 can be moved back and forth within such a range that the locking projections 64 are movable within the recessed groove 44. Further, since the ends of the recessed groove 44 are used as the end walls 441, the respective side fences 52 can be easily positioned by bringing the respective locking projections 64 into contact with the end walls 441 of the recessed groove 44 upon assembling the sheet feed tray 30. Further, the racks 70 can be held in close contact with the bottom plate 41 since the locking projections 64 are fitted into the recessed groove 44, wherefore the total thickness of the racks 70 and the bottom plate 41 can be minimally held down. The present invention is not limited to the foregoing embodiment and also embraces the following contents. (1) Although the copier 10 is taken as an example of an apparatus, to which the sheet feed tray 30 is applied, in the description of the foregoing embodiment, the present invention is also applicable to other image forming apparatuses such as facsimile machines and printers. (2) Although the sheet feed tray 30 is for feeding documents P to the image feeder 22 provided in the sheet feeder 20 in the foregoing embodiment, the sheet feed tray 30 may be for transfer sheets to which images are transferred. In this case, a sheet according to the present invention is a transfer sheet. (3) In the foregoing embodiment, the recessed groove 44 is formed in the underside of the bottom plate 41 and the respective end walls 441 of this recessed groove 44 serve as contact portions according to the present invention. Instead of providing such a recessed groove 44, bottom-plate locking projections facing the locking projections 64 may be provided at the underside of the bottom plate 41. (4) In the foregoing embodiment, the bottom plate 41 is formed with the recessed groove 44, whereas the supporting members 60 are provided with the locking projections 64. Instead, the racks 70 may be formed with recessed grooves, whereas the bottom plate 41 may be provided with locking projections fittable into these recessed grooves. (5) In the foregoing embodiment, at the time of assembling the side-fence retaining member 40, the pinion member 80 is engaged with the respective racks 70 with the pair of side fences 52 positioned at a maximal distance from each other. Instead, the pinion member 80 may be engaged with the respective racks 70 with the pair of side fences 52 positioned at a minimum distance from each other. (6) Although the pair of side fences 52 is positioned symmetrically with respect to the center position of the bottom plate 41 in the foregoing embodiment, they may not be positioned symmetrically. The aforementioned specific embodiment mainly embraces features of the inventions having the following constructions. A sheet feed tray according one aspect of the present invention comprises a bottom plate on which a sheet is to be placed; a pair of side fences for positioning the opposite widthwise sides of a sheet placed on the bottom plate; an interlocking mechanism for interlocking movements of the pair of side fences in directions toward and away from each other, the interlocking mechanism including a pair of racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate rotatably about its central axis thereof and engageable with the pair of racks; locking projections disposed at the respective rack sides and projecting toward the bottom plate side; and contact portions disposed at the bottom plate side and engageable with the locking projections with the pair of side fences maximally or minimally spaced apart from each other. An image forming apparatus according to another aspect of the present invention comprises an apparatus main body for applying an image forming process to a sheet; a sheet feeder attached to the apparatus main body to feed a sheet or a document to be read toward a specified position of the apparatus main body; and a sheet feed tray provided in the sheet feeder, adapted to bear the sheet or the document and having the inventive construction. According to the above construction, the locking projections are disposed at the respective rack sides and the contact portion engageable with the locking projections with the respective side fences maximally or minimally spaced apart are disposed at the bottom plate side. Thus, upon assembling the sheet feed tray, the pair of side fences are maximally or minimally spaced apart by engaging the locking projections of the respective rack sides with the contact portions of the bottom plate side. By assembling the pinion to engage it with the respective racks in this state, the assembling of the sheet feed tray is completed while the relative positioning of the pair of side fences (phase alignment of the side fences) is properly performed. Accordingly, the sheet feed tray can be quickly and easily assembled with the pair of side fences properly positioned without using a jig such as a scale, wherefore assembling operability is remarkably improved and maintainability, for example, upon conducting a repair can also be improved. In the above construction, it is preferable that the bottom plate is recessed to form a recessed groove which extends in moving directions of the side fences and into which the locking projections are fittable, and that the contact portions are end walls formed at ends of the recessed groove. With such a construction, by fitting the locking projections into the recessed groove, the side fences are moved back and forth within such a range that the locking projections are movable in the recessed groove. At the time of assembling the sheet feed tray, the respective locking projections can be engaged with the end walls of the recessed groove. Further, the racks can be closely attached to the bottom plate by fitting the locking projections into the recessed groove, wherefore the total thickness of the racks and the bottom plate can be maximally held down. In the above construction, the contact portions are preferably bottom-plate side locking projections projecting from the bottom plate in correspondence with the locking projections. With such a construction, the locking projections are engaged with the bottom-plate side locking projections projecting from the bottom plate at the time of assembling the sheet feed tray. It is sufficient to provide the bottom plate with the bottom-plate side locking projections as the contact portions, which contributes to a reduction in the production cost of the sheet feed tray. A sheet feed tray according to another aspect of the present invention comprises a bottom plate on which a sheet is to be placed; a pair of side fences for positioning the opposite widthwise sides of a sheet placed on the bottom plate; an interlocking mechanism for interlocking movements of the pair of side fences in directions toward and away from each other, the interlocking mechanism including a pair of racks integrally attached to the respective side fences with toothed surfaces thereof opposed to each other and movable along the bottom plate, and a pinion provided on the bottom plate rotatably about its central axis thereof and engageable with the pair of racks; locking projections disposed at the bottom plate side and projecting toward the rack sides; and contact portions disposed at the respective racks and engageable with the locking projections with the pair of side fences maximally or minimally spaced apart from each other. With such a construction as well, operability in assembling the side fences can be remarkably improved similar to the above. This application is based on patent application No. 2006-053146 filed in Japan, the contents of which are hereby incorporated by references. As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to embraced by the claims.
|
B
|
B65
|
B65H
|
31
|
36
|
|||
11692558
|
US20070233715A1-20071004
|
RESOURCE MANAGEMENT SYSTEM, METHOD AND PROGRAM FOR SELECTING CANDIDATE TAG
|
ACCEPTED
|
20070920
|
20071004
|
[]
|
G06F700
|
["G06F700", "G06F1730"]
|
9069867
|
20070328
|
20150630
|
715
|
234000
|
94935.0
|
HILLERY
|
NATHAN
|
[{"inventor_name_last": "Rekimoto", "inventor_name_first": "Junichi", "inventor_city": "Tokyo", "inventor_state": "", "inventor_country": "JP"}]
|
Resource management system, method and program for selecting candidate tag are provided. The tag can be readily attached to a resource by presenting a candidate tag also to a resource newly registered in a database. The degree of similarity of a new registration resource to each of a plurality of already-registered resources that have been already registered in the database is calculated. A tag attached to an already-registered resource of which the degree of similarity is large is selected as a candidate for a tag to be attached to the new registration resource. Thereby, a candidate tag can be also presented to a resource newly registered in the database. A user can further readily attach a tag compared to a conventional system.
|
1. A resource management system comprising: degree-of-similarity calculating means for calculating the degree of similarity of a new registration resource newly registered in a database, to each of a plurality of already-registered resources that have been already registered in the database; and candidate tag selecting means for selecting a tag attached to an already-registered resource of which said degree of similarity calculated by said degree-of-similarity calculating means is large, as a candidate for a tag to be attached to said new registration resource. 2. The resource management system according to claim 1, wherein; said resource is a web page, and said degree-of-similarity calculating means calculates the degree of similarity between text date described in an already-registered web page and text data described in a new registration web page. 3. A method for selecting a candidate tag, comprising: the degree-of-similarity calculating step of calculating the degree of similarity of a new registration resource newly registered in a database, to each of a plurality of already-registered resources that have been already registered in the database; and the candidate tag selecting step of selecting a tag attached to an already-registered resource of which said degree of similarity calculated in said degree-of-similarity calculating step is large, as a candidate for a tag to be attached to said new registration resource. 4. A candidate tag selecting program embodied on a computer-readable medium for making an information processing unit executes: the degree-of-similarity calculating step of calculating the degree of similarity of a new registration resource newly registered in a database, to each of a plurality of already-registered resources that have been already registered in the database; and the candidate tag selecting step of selecting a tag attached to an already-registered resource of which said degree of similarity calculated in said degree-of-similarity calculating step is large, as a candidate for a tag to be attached to said new registration resource.
|
<SOH> BACKGROUND <EOH>The present invention relates to a resource management system, a method for selecting a candidate tag, and a candidate tag selecting program, and is applicable to the case of managing many resources by using a tag. Hereinafter, on the Internet, a system in which many users attach a tag to a common resource (a picture and a web bookmark) for arrangement has been generally used. For example, in the Flickr that is a picture sharing service for sharing a picture on the network (see http://www.flickr.com), an arbitrary tag such as “TOKYO”, “FOOD” or “PARTY” is attached to (associated with) a picture uploaded on a database, so that only a resource having a specified tag can be retrieved and extracted. Further, because resources are unnecessary to be classified in a specified hierarchical structure, a plurality of different images can be attached to one resource as tags, so that resources can be arranged further flexibly. This tag attachment may be individually performed. However, in the case where many users share the same resource, it works further effectively. For example, in the del.icio.us that is a social bookmark service for sharing an web bookmark on the network (see http://del.icio.us), a user can attach an arbitrary tag such as “PROGRAMMING”, “GUIDE”, “SERVICE” or “SHOPPING” to a bookmarked web page for arrangement. Further, this del.icio.us has a candidate tag present function in that if the same web page has been already bookmarked by other user, a tag attached by the above other user is presented as a candidate tag. Thereby, if a desired tag has been already attached by other user, it is unnecessary to enter the character string, and the user can readily perform tag attachment by selecting the presented candidate tag with a mouse or the like. However, in the aforementioned candidate tag present function, when in newly performing a bookmark registration of an web page that has not been bookmarked by other user, because existent tag information cannot be used, the user have to enter a tag explicitly. Therefore, there has been a tendency that as to a famous web page of which the degree of sharing is high such that many tags have been already attached, plentiful tags will be attached and it can be readily retrieved, however, as to an web page newly bookmarked, because a tag attachment operation is complicated, tag attachment is not performed so actively. As the above, in a conventional social bookmark service, there has been a problem that a tag attachment operation to a new bookmark is complicated.
|
<SOH> SUMMARY <EOH>In view of the foregoing, it is desirable to provide a resource management system, a method for selecting a candidate tag, and a candidate tag selecting program in that a tag can be readily attached to a resource newly registered. The present application can be applied to various resource management systems. According to an embodiment, there is provided degree-of-similarity calculating means for calculating the degree of similarity of a new registration resource newly registered in a database, to each of a plurality of already-registered resources that have been already registered in the database, and candidate tag selecting means for selecting a tag attached to an already-registered resource of which the degree of similarity calculated by the degree-of-similarity calculating means is large, as a candidate for a tag to be attached to the new registration resource. By selecting a tag attached to a resource of which the degree of similarity is high as a candidate tag, a candidate tag can be also presented to a resource newly registered in a database. Thereby, a user can further readily attach a tag compared to a conventional system. The nature, principle and utility of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings in which like parts are designated by like reference numerals or characters. Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures. BRFSUM description="Brief Summary" end="tail"?
|
CROSS REFERENCE TO RELATED APPLICATION The present application claims priority to Japanese Patent Application JP 2006-095051 filed in the Japanese Patent Office on Mar. 30, 2006, the entire contents of which is being incorporated herein by reference. BACKGROUND The present invention relates to a resource management system, a method for selecting a candidate tag, and a candidate tag selecting program, and is applicable to the case of managing many resources by using a tag. Hereinafter, on the Internet, a system in which many users attach a tag to a common resource (a picture and a web bookmark) for arrangement has been generally used. For example, in the Flickr that is a picture sharing service for sharing a picture on the network (see http://www.flickr.com), an arbitrary tag such as “TOKYO”, “FOOD” or “PARTY” is attached to (associated with) a picture uploaded on a database, so that only a resource having a specified tag can be retrieved and extracted. Further, because resources are unnecessary to be classified in a specified hierarchical structure, a plurality of different images can be attached to one resource as tags, so that resources can be arranged further flexibly. This tag attachment may be individually performed. However, in the case where many users share the same resource, it works further effectively. For example, in the del.icio.us that is a social bookmark service for sharing an web bookmark on the network (see http://del.icio.us), a user can attach an arbitrary tag such as “PROGRAMMING”, “GUIDE”, “SERVICE” or “SHOPPING” to a bookmarked web page for arrangement. Further, this del.icio.us has a candidate tag present function in that if the same web page has been already bookmarked by other user, a tag attached by the above other user is presented as a candidate tag. Thereby, if a desired tag has been already attached by other user, it is unnecessary to enter the character string, and the user can readily perform tag attachment by selecting the presented candidate tag with a mouse or the like. However, in the aforementioned candidate tag present function, when in newly performing a bookmark registration of an web page that has not been bookmarked by other user, because existent tag information cannot be used, the user have to enter a tag explicitly. Therefore, there has been a tendency that as to a famous web page of which the degree of sharing is high such that many tags have been already attached, plentiful tags will be attached and it can be readily retrieved, however, as to an web page newly bookmarked, because a tag attachment operation is complicated, tag attachment is not performed so actively. As the above, in a conventional social bookmark service, there has been a problem that a tag attachment operation to a new bookmark is complicated. SUMMARY In view of the foregoing, it is desirable to provide a resource management system, a method for selecting a candidate tag, and a candidate tag selecting program in that a tag can be readily attached to a resource newly registered. The present application can be applied to various resource management systems. According to an embodiment, there is provided degree-of-similarity calculating means for calculating the degree of similarity of a new registration resource newly registered in a database, to each of a plurality of already-registered resources that have been already registered in the database, and candidate tag selecting means for selecting a tag attached to an already-registered resource of which the degree of similarity calculated by the degree-of-similarity calculating means is large, as a candidate for a tag to be attached to the new registration resource. By selecting a tag attached to a resource of which the degree of similarity is high as a candidate tag, a candidate tag can be also presented to a resource newly registered in a database. Thereby, a user can further readily attach a tag compared to a conventional system. The nature, principle and utility of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings in which like parts are designated by like reference numerals or characters. Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a block diagram showing an overall configuration of a bookmark sharing system. FIG. 2 is a schematic diagram showing the configuration of a bookmark registration screen. FIG. 3 is a flowchart of a candidate tag selecting processing procedure. FIG. 4 is a schematic diagram for explaining the calculation of a tag factor corresponding to the attached number of tags. FIG. 5 is a schematic diagram for explaining a text management system to which an embodiment of the present invention is applied. DETAILED DESCRIPTION Preferred embodiments will be described with reference to the accompanying drawings. (1) Overall Configuration of Social Bookmark System Referring to FIG. 1, the reference numeral 1 designates a bookmark sharing system as a whole. The bookmark sharing system 1 is formed by that a plurality of user terminals 4 are connected to a bookmark server 2 via the Internet 3. Each user terminal 4 is an information processing unit having an Internet connection function such as a personal computer, a personal digital assistant (PDA) and a cellular phone. Each of them accesses an web server on the Internet 3 (not shown) according to a user operation, obtains web page data, and displays an web page based on the above obtained web page data to make a user view it. In addition to this, in the bookmark sharing system 1, by that the user of the user terminal 4 registers a user account on the bookmark server 2, a bookmark list peculiar to the above user account can be formed in the bookmark server 2. The registration user of the bookmark sharing system 1 (hereinafter, it is also simply referred to as “user”) can register the bookmark of an arbitrary web page in the user's own bookmark list (hereinafter, it is also simply referred to as “bookmark an web page”). Additionally, in the bookmark sharing system 1, when in registering a bookmark in the bookmark list, the user can attach an arbitrary tag to the above bookmark. Further, the user also can retrieve a bookmark registered by other user, by using an arbitrary tag as a keyword. That is, in the bookmark server 2, the lists of their respective bookmarks of each user have been stored in a bookmark database in a hard disk drive 11 (FIG. 2). If receiving a bookmark registration request from the user terminal 4, the Central Processing Unit (CPU) 10 of the bookmark server 2 enters this in the bookmark list of the registration user by associating an web page with a tag that are specified in the above bookmark registration request. Further, if receiving a bookmark retrieval request from the user terminal 4, the CPU 10 of the bookmark server 2 performs retrieval from the bookmark database, by using the tag specified by the above registration request as a keyword, extracts a bookmark to which the same tag as the specified tag has been attached as the retrieval result, and returns this to the user terminal 4. In this manner, in the bookmark sharing system 1, users can register their own bookmark lists in the bookmark server 2 respectively. At the same time, many bookmarks registered by each user can be shared among all of the registration users, and a desired bookmark can be retrieved using a tag from among the above many bookmarks. (2) Automatic Presentation of Candidate Tag (2-1) Configuration of Bookmark Registration Screen In addition to the above configuration, at the time when a user newly registers an arbitrary web page in a bookmark list, if this new registration page has been already registered by other user, the bookmark server 2 presents a tag attached to the already-registered page by the other user or the like as a candidate tag. That is, if accepting a predetermined bookmark registration operation by the user via input means such as a keyboard, the user terminal 4 transmits the Uniform Resource Locator (URL) of the new registration page that was specified by the user as an object of a bookmark in this operation to the bookmark server 2, with a bookmark registration temporary request. If receiving the bookmark registration temporary request transmitted from the user terminal 4, by responding this, the CPU 10 of the bookmark server 2 returns display data for displaying a bookmark registration screen 20 shown in FIG. 2 to the user terminal 4. Thereby, the bookmark registration screen 20 is displayed in the above user terminal 4. As shown in FIG. 2, in the bookmark registration screen 20, a URL display field 21 to display the URL of the new registration page specified as the bookmark object in the bookmark registration temporary request (hereinafter, it is referred to as “new registration URL”), a page name display field 22 to display the name of the new registration page, a tag display field 23 to display a tag to be attached to the new registration page, and a bookmark registration button 24 to register the new registration page in the user's bookmark list are displayed. In the URL display field 21, the page name display field 22 and the tag display field 23, an arbitrary character can be entered by the user via input means such as a keyboard provided in the user terminal 4. For example, in the page name display field 22, a page name attached to the new registration page is automatically displayed. However, the above page name can be freely changed by the user. Similarly, the URL displayed in the URL display field 21 can also be freely changed by the user. Thereby, a lower-order page, a higher-order page or the like in the web page can be arbitrary specified and set as a new registration URL. Further, in the tag display field 23, one or a plurality of character strings to be attached to a bookmark can be arbitrary entered by the user as a tag. Further, at a part lower than the tag display field 23 in the bookmark registration screen 20, one or a plurality of candidate tags 25 recommended by the bookmark server 2 for the new registration URL specified in the bookmark registration temporary request are displayed. This candidate tag 25 is that the bookmark server 2 selected a tag related to the new registration URL by candidate tag selecting processing that will be described later. Then, the user can select an arbitrary one of the displayed candidate tags 25 to make it display in the tag display field 23. That is, if accepting a candidate tag 25 selecting operation by the user via the input means such as a keyboard, by responding to this, the user terminal 4 copies the character string of the selected candidate tag 25, and displays it in the tag display field 23. In this manner, in the bookmark sharing system 1, the bookmark server 2 presents candidate tags 25 related to a new registration URL. Thereby, the user can readily perform tag attachment. Then, if accepting a pressing operation of the bookmark registration button 24 by the user via the input means, by responding to this, the user terminal 4 transmits the new registration URL and the page name, and an attached tag to the bookmark server 2 with a bookmark registration request. If receiving the bookmark registration request transmitted from the user terminal 4, by responding to this, the CPU 10 of the bookmark server 2 associates the page name and the tag with the new registration URL received at the same time, and registers this in this user's bookmark list as an already-registered URL. Further, at this time, the CPU 10 of the bookmark server 2 accesses an web page specified by the new registration URL, obtains a document described in the above web page as already-registered text data, and registers this in the bookmark list in association with the already-registered URL. (2-2) Candidate Tag Selecting Processing Next, the aforementioned candidate tag selecting processing for a new registration URL by the bookmark server 2 will be described in detail. If receiving a bookmark registration temporary request from the user terminal 4, the CPU 10 of the bookmark server 2 retrieves the same URL as the new registration URL that was received with the above bookmark registration temporary request from the bookmark lists of all of users on the bookmark database. If the same URL as the new registration URL has been registered in some bookmark lists as an already-registered URL, the CPU 10 obtains a tag attached to the above already-registered URL from the bookmark database, and transmits this to the user terminal 4 as a candidate tag with display data for displaying the bookmark registration screen 20. On the contrary, if the same URL as the new registration URL has not been registered in any bookmark lists (that is, if this URL will be registered in the bookmark database for the first time), the CPU 10 cannot select a candidate tag in this state. Therefore, the CPU 10 of the bookmark server 2 accesses a new registration page specified by the above new registration URL, and obtains a character string described in the above new registration page as new registration text data. Then, the CPU 10 compares the obtained new registration text data with all of already-registered text data stored in the bookmark database and calculates the degree of similarity respectively (the calculating method will be described later), selects a predetermined number of (for example, ten) already-registered text data of which the degree of similarity to the above new registration text data is high, and transmits a tag attached to the already-registered URL corresponding to the above selected already-registered text data of which the degree of similarity is high to the user terminal 4 as a candidate tag, with display data for displaying the bookmark registration screen 20. Then, the user terminal 4 displays the candidate tag received from the bookmark server 2 in the bookmark registration screen 20 to present this to the user. In this manner, the CPU 10 of the bookmark server 2 retrieves an already-registered page having the contents similar to a new registration page, and selects a tag attached to this as a candidate tag. Thereby, a candidate tag can be also presented to a bookmark registered in the bookmark database for the first time. (2-3) Calculation of Degree of Similarity and Selection of Candidate Tag Next, the aforementioned method for calculating the degree of similarity between new registration text data and already-registered text data, and a method for selecting a candidate tag will be described. As a method for calculating the degree of similarity between text data, a method for obtaining the number of co-occurrence of words, a method using Latent Semantics Analysis (LSA), and the like have been generally used. These various methods for calculating the degree of similarity can be used in the present invention. Further, as a method for selecting a candidate tag, if the degree of similarity between new registration text data and already-registered text data Sim(Newpage,Webi) was calculated as being within −1 to 1, a tag attached to the already-registered page is added by the following formula: W(Tagj)≡Σ{Sim(NewPage,Webi)*(Σ hasTag(Webi,Tagj))} (1) Here, the W(Tag) is an weighting factor to determine whether or not Tag should be set as a candidate. Further, if the tag Tagj has been attached to a certain web page Webi, the tag factor hasTag(Webi,Tagj) becomes 1, and if the tag Tagj has not been attached, it becomes 0. In this manner, the weighting factor W(Tag) can be calculated about the respective tags attached to all of the already-registered pages. Thereby, an adequate number of (for example, ten) tags of which the above weighting factor W(Tag) is large are selected, and are transmitted to the user terminal 4 as candidate tags. (2-4) Candidate Tag Selecting Processing Procedure Next, the procedure of the aforementioned processing that the bookmark server 2 selects a candidate tag for a new registration page and transmits this to the user terminal 4 will be described in detail, with reference to a flowchart shown in FIG. 3. The CPU 10 of the bookmark server 2 enters a candidate tag selecting processing procedure RT1 from the start step, and proceeds to step SP1. If receiving a new registration URL from the user terminal 4 with a bookmark registration temporary request, the CPU 10 proceeds to the next step SP2. In step SP2, the CPU 10 retrieves the same URL as the above new registration URL from already-registered URL in the bookmark database, by using the received new registration URL as a retrieval keyword, and proceeds to the next step SP3. In step SP3, the CPU 10 determines whether the same already-registered URL as the new registration URL has been registered in the bookmark database, based on the retrieval result. If an affirmative result is obtained in step SP3, this means that an web page that is going to be performed bookmark registration has already been registered in the bookmark database by other user. At this time, the CPU 10 proceeds to step SP4 to select a tag attached to the same already-registered URL as the new registration URL as a candidate tag, and proceeds to step SP7. On the contrary, if a negative result is obtained in this step SP3, this means that the above web page will be registered in the bookmark database for the first time. At this time, the CPU 10 proceeds to step SP5. In step SP5, the CPU 10 serving as degree-of-similarity calculating means accesses a new registration page specified by the new registration URL, obtains a character string described in the above page as new registration text data, and compares the above new registration text data with all of the already-registered text data stored in the bookmark database and calculates the degree of similarity respectively. Then, the CPU 10 proceeds to the next step SP6. In step SP6, the CPU 10 serving as candidate tag selection means calculates the respective weighting factors W(Tag) of tags attached to each already-registered page based on the calculated degree of similarity, and selects a tag of which the above weighting factor W(Tag) is large as a candidate tag. Then, the CPU 10 proceeds to the next step SP7. And then, in step SP7, the CPU 10 transmits the selected candidate tag to the user terminal 4, and proceeds to the next step SP8 to finish the candidate tag selecting processing procedure. (3) Operation and Effect According to the above configuration, if a new registration page accepted from the user terminal 4 has been already bookmarked by other user, the bookmark server 2 in the bookmark sharing system 1 selects a tag that has been attached to this page by that other user as a candidate tag, and transmits this to the user terminal 4. Thereby, a tag attachment operation to the above new registration page can be readily performed. Further, even if the new registration page accepted from the user terminal 4 has not been bookmarked by other user, the bookmark server 2 selects a tag that has been attached to a page having the similar contents to the new registration page, in all of the web pages that have been performed bookmark registration in the bookmark database as a candidate tag, and transmits this to the user terminal 4. Thereby, a tag attachment operation can be also readily performed to an web page that will be completely newly performed bookmark registration in the bookmark database. (4) Other Embodiments In the aforementioned embodiment, it has dealt with the case where a tag factor is calculated based on the presence of tag attachment, by setting a tag factor hasTag(Webi,Tagj)=1 when a tag Tagj has been attached to a certain web page Webi, and by setting a tag factor hasTag(Webi,Tagj)=0 when a tag Tagj has not been attached. However, the present invention is not only limited to this but also the tag factor may be calculated by considering the number of users who attached a tag. For example, it can be considered that when n pieces of tag Tagj have been attached to a certain web page Webi, a tag factor HasTag(Webi,Tagj)=n is set. That is, in a social tagging system as the bookmark sharing system 1 of an embodiment of the present invention, there is often a case where a plurality of users attach the same tag to a certain web page. For example, in FIG. 4, to a certain web page WebA, a tag “WINE” has been attached by three users, a tag “BAR” has been attached by two users, and a tag “RESTAURANT” has been attached by one user. A tag factor in this case is hasTag(WebA,WINE)=3, hasTag(WebA,BAR)=2, and hasTag(WebA,RESTAURANT)=1. In this manner, if calculating a weighting factor W(Tag) using a tag factor in consideration of the attached number of tags, a candidate tag which reflects tag attachment state and is highly accurate can be selected. Further, in the aforementioned embodiment, it has dealt with the case where the present invention is applied to tag attachment to an web page in the bookmark sharing system 1. However, the present invention is not only limited to this but also it can be widely applied to the case of attaching a tag to various resources of which the degree of similarity can be calculated. As such resources to which the present invention is applicable, audio data and image data, and the like can be considered. Then, as a method for calculating the degree of similarity for audio data, a similarity of power spectrum in musical compositions (J.-J. Aucouturier and F. Pachet: Music similarity measures: What's the use? Proc. ISMIR 2002, pp. 157•63 (2002)), a similarity of rhythm (J. Paulus and A. Klapuri: Measuring the similarity of rhythmic patterns. Proc. ISMIR 2002, pp. 150-156 (2002)), the feature amount of a modulation spectrum (Dixon, E. Pampalk and G. Widmer: Classification of dance music by periodicity patterns. Proc. ISMIR 2003, pp. 159•65 (2003), or the like can be used. On the other hand, as a method for calculating the degree of similarity for image data, a method based on fractal images (Takanori Yokoyama, Toshinori Watanabe and Ken Sugawara: “Feature Amount Based on Correspondence of Fractal Coded Images and Similarity Retrieval”, the technical report by the Institute of Image Information and Television Engineers, Vol. 26, No. 54, pp. 29-32, 2002), or the like can be used. Further, in the aforementioned embodiment, it has dealt with the case where the present invention is applied to a system in that a plurality of users attach a tag to a resource to manage information as a social tagging system. However, the present invention is not only limited to this but also can be applied to an individual information management system in that one user manages information. As an example of such individual information management system, a text management system in that a tag is attached to a text memo and is managed on a computer can be considered, for example. That is, as shown in FIG. 5, in the text management system, an arbitrary tag is attached to a text memo entered by a user, and the text memo can be retrieved using the above tag. Then, if a new text memo is entered by the user, the CPU of a computer executing the text management system calculates the degree of similarity between the above new text memo and existent text memos already entered, and presents a tag that has been attached to a text memo of which the degree of similarity is high as a candidate tag for the new text memo. Thereby, in this text management system, the user can perform tag attachment to a text memo with a simple operation. According to an embodiment, there is provided degree-of-similarity calculating means for calculating the degree of similarity of a new registration resource newly registered in a database, to each of a plurality of already-registered resources that have been already registered in the database, and candidate tag selecting means for selecting a tag attached to an already-registered resource of which the degree of similarity calculated by the degree-of-similarity calculating means is large, as a candidate for a tag to be attached to the new registration resource. Thereby, a resource management system, a method for selecting a candidate tag, and a candidate tag selecting program in that a candidate tag can be also presented to a resource newly registered in a database, and a user can further readily attach a tag compared to a conventional system can be realized. It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
|
G
|
G06
|
G06F
|
7
|
00
|
|||
11864354
|
US20090088790A1-20090402
|
RETRIEVAL CATHETER
|
ACCEPTED
|
20090318
|
20090402
|
[]
|
A61M2900
|
["A61M2900"]
|
9597172
|
20070928
|
20170321
|
606
|
191000
|
82264.0
|
RODJOM
|
KATHERINE
|
[{"inventor_name_last": "Parodi", "inventor_name_first": "Juan C.", "inventor_city": "Pinecrest", "inventor_state": "FL", "inventor_country": "US"}, {"inventor_name_last": "Cheer", "inventor_name_first": "John", "inventor_city": "Manasquan", "inventor_state": "NJ", "inventor_country": "US"}, {"inventor_name_last": "Cully", "inventor_name_first": "Edward H.", "inventor_city": "Flagstaff", "inventor_state": "AZ", "inventor_country": "US"}, {"inventor_name_last": "Vonesh", "inventor_name_first": "Michael J.", "inventor_city": "Flagstaff", "inventor_state": "AZ", "inventor_country": "US"}, {"inventor_name_last": "Young", "inventor_name_first": "Jeremy P.", "inventor_city": "Flagstaff", "inventor_state": "AZ", "inventor_country": "US"}]
|
A retrieval catheter operable by a single clinician that will neither displace a deployed stent nor cause undue trauma to the vascular lumen or lesion. The retrieval catheter may be sized to accommodate both a guidewire and a balloon wire. The retrieval catheter is easy to navigate through tortuous passageways and will cross a previously deployed stent or stent-graft easily with minimal risk of snagging on the deployed stent or stent graft. The sheath and dilator are adapted to allow a guidewire or balloon wire to pass through the walls of both and to allow the sheath and dilator to move axially with respect to each other.
|
1. A catheter assembly, comprising: a sheath having a sheath sidewall and a sheath exchange port through the sheath sidewall; and a dilator having a dilator sidewall, a tapered distal end, and a dilator exchange port through the dilator sidewall, said dilator positioned in the sheath adapted to slide relative to the sheath between an extended position and a retracted position wherein the tapered distal end is fully withdrawn into the sheath; wherein the assembly allows the dilator to slide between the extended and retracted positions while a guidewire extends through the sheath exchange port and dilator exchange port. 2. A catheter assembly as claimed in claim 1 wherein said sheath exchange port is an aperture through the sheath sidewall. 3. A catheter assembly as claimed in claim 2 wherein said dilator exchange port is a longitudinally oriented slot having a length that is greater than a length of said aperture through the sheath sidewall. 4. A catheter assembly as claimed in claim 1 wherein dilator exchange port is a longitudinally oriented slot that extends from a proximal end to the tapered distal end of the dilator. 5. A catheter assembly as claimed in claim 1 wherein said sheath exchange port has a greater length than said dilator exchange port. 6. A catheter assembly as claimed in claim 1 wherein at least a portion of said guidewire extends through a guidewire threading tube. 7. A catheter assembly as claimed in claim 1 configured for filter retrieval. 8. A catheter assembly as claimed in claim 1 configured for balloon retrieval. 9. A catheter assembly comprising: a tubular dilator component having a length extending between a tapered distal end and a proximal end thereof and having a wall, said tubular dilator component having a slot extending through the wall thereof, said slot having a length extending along a portion of the length of the tubular dilator component, said slot being located nearer to the tapered distal end of the tubular dilator component; and a tubular sheath component located around the tubular dilator component, said tubular sheath component having a wall and having a length extending between distal and proximal ends thereof, wherein the length of the tubular sheath component is less than the length of the tubular dilator component, said tubular sheath component having an aperture through the wall thereof and located nearer to the distal end of the tubular sheath component. 10. A catheter assembly according to claim 9 further comprising a guidewire having a length wherein a portion of said length is contained within a guidewire threading tube, said guidewire extending through the tapered distal end of the tubular dilator component, and said guidewire within the guidewire threading tube extending through the slot of the dilator component and through the aperture of the tubular catheter component. 11. A catheter assembly according to claim 9 wherein the tubular dilator component and the tubular sheath components may be moved axially with respect to each other for a length at least equal to the length of the slot of the dilator component and wherein when moved along the length of the slot, the tubular dilator component and the tubular sheath component move from a first axial positional relationship wherein the tapered distal end of the tubular dilator component extends beyond the distal end of the tubular sheath component, to a second axial positional relationship wherein the distal end of the tubular sheath component extends beyond the tapered distal end of the tubular dilator component. 12. A method of retrieving a first endoluminal device located distal to a second endoluminal device, wherein a guidewire extends proximally from the first endoluminal device past the second endoluminal device and beyond to a proximal end of the guidewire extending out of a patient's body, said method comprising: a.) providing a catheter assembly comprising an inner and an outer tube fifted around the inner tube, both tubes having walls with openings through the walls and distal ends with distal end openings, wherein the openings are provided through the walls of both tubes in cooperative relationship to allow a guidewire to pass through the walls of both tubes and wherein the inner and outer tubes are movable axially with respect to each other; and b.) positioning the distal end of the inner tube so that it extends distally beyond the distal end of the outer tube; and c.) inserting the proximal end of the guidewire into the distal end of the inner tube and continuing to pass the guidewire through the inner tube until the proximal end of the guidewire extends through the openings through the walls of both tubes; and d.) passing the catheter assembly in a distal direction over the guidewire until the distal ends of the inner tube and outer tube have passed beyond the second endoluminal device and the distal end of the inner tube is located proximal to the first endoluminal device; and e.) positioning the distal end of the outer tube so that it extends distally beyond the distal end of the inner tube; and f.) moving the distal end opening of the outer tube with respect to the first endoluminal device to cause the first endoluminal device to enter the distal end opening of the outer tube and reside in the distal end of the outer tube; and g.) withdrawing the catheter. 13. A method of retrieving a first endoluminal device through a sidewall of a second endoluminal device, said method comprising: a.) providing a catheter assembly comprising an inner and an outer tube fitted around the outer tube, both tubes having walls with openings through the walls and distal ends with distal end openings, wherein the openings are provided through the walls of both tubes in cooperative relationship to allow a guidewire to pass through the walls of both tubes and wherein the inner and outer tubes are movable axially with respect to each other; and b.) positioning the distal end of the inner tube so that it extends distally beyond the distal end of the outer tube; and c.) inserting the proximal end of the guidewire into the distal end of the inner tube and continuing to pass the guidewire through the inner tube until the proximal end of the guidewire extends through the openings through the walls of both tubes; and d.) inserting the catheter assembly through the sidewall of the second endoluminal device; and e.) passing the catheter assembly in a distal direction over the guidewire until the distal ends of the inner tube and outer tube have passed beyond the second endoluminal device and the distal end of the inner tube is located proximal to the first endoluminal device; and f.) positioning the distal end of the outer tube so that it extends distally beyond the distal end of the inner tube; and g.) moving the distal end opening of the outer tube with respect to the first endoluminal device to cause the first endoluminal device to enter the distal end opening of the outer tube and reside in the distal end of the outer tube; and h.) withdrawing the catheter.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>The field of endovascular surgery is rapidly becoming an alternative to more traditional surgeries such as carotid endarterectomy, coronary artery bypass grafting, aortic aneurysm repair, and vascular grafting. Percutaneous intervention is becoming the primary means for revascularization in many such procedures. Distal embolization of friable debris from within the diseased conduit remains a risk of endovascular surgery, potentially involving complications such as myocardial infarction and ischemia. Devices such as balloon catheters and embolic filters have been used to control and remove embolic debris dislodged from arterial walls during endovascular procedures, distal to an interventional procedure site. Percutaneous introduction of these devices typically involves access via the femoral artery lumen of the patient's groin vasculature. An introducer sheath may then be inserted in the wound, followed by a guide catheter that is advanced to the site to be treated. A guidewire is usually introduced into the lumen of the vasculature and advanced distally, via manipulation by the clinician, to cross the lesion or area of treatment. Then a catheter containing the device(s) may be employed to traverse the length of the guidewire to the desired deployment location. Once the distal protection device is deployed, the lesion or stenosis is available for treatment. A common practice for treating the lesion or stenosis is to deploy a stent at the target location to increase the lumen size of the vessel and maintain or increase patency. When feeding a guidewire through the lumen of a stent, there is a possibility that the tip of the wire will become diverted and/or ensnared by the stent. This possibility increases with increasing vessel tortuosity. This problem has been addressed through the use of a soft, flexible, floppy tip at the distal end of the wire to improve steerability and reduce the possibility of engaging the stent or peripheral vasculature. However, a flat-tipped catheter advanced over a guidewire with an inside diameter larger than the outside diameter of the guidewire, presents a sharp edge to the vessel or stent at the point of tangential contact. The exposure of this edge increases with vessel tortuosity and with an increase in differences between the guidewire outside diameter and catheter inside diameter. Embolic filters and balloons are often deployed by traversing the lesion being treated and deploying the device distally. If a balloon wire or embolic filter becomes caught in the patient's vasculature or is otherwise prevented from removal by a stent, such as the device becoming entrapped within the struts of a stent, then the clinician is typically required to perform higher risk procedures to retrieve them. These include subjecting the device to greater retrieval forces, and removal through invasive surgical techniques. The former increases the risk of the device becoming detached from its guidewire or catheter, whereas the latter exposes the patient to the increased risks of open surgical extraction. Successful retrieval of these devices in situations other than those originally anticipated, without intimal dissection, plaque, hemorrhage, or vessel occlusion, is an important advancement in the field of interventional endovascular surgery.
|
<SOH> SUMMARY OF THE INVENTION <EOH>A retrieval catheter assembly is described that may be operated by a single clinician and upon delivery will neither permanently displace a previously deployed stent nor cause undue trauma to the vascular lumen or lesion. The retrieval catheter assembly will enable a tubular retrieval sheath to be advanced over a wire between the outside diameter of a deployed stent and the vessel wall, or over a guidewire through the lumen of a stent and retrieve various devices, e.g., filters, balloons, etc. distal to the stent. The retrieval catheter may also enable a tubular sheath to be directed through the sidewall of a stent. The retrieval catheter assembly comprises a sheath having a balloon wire or guidewire exchange port through the sidewall of the sheath and a dilator, which is positioned in the sheath lumen. The sheath has a body with relatively stiff proximal and distal sections and with a flexible middle section, which aids in the operation of the device. The dilator is adapted to slide axially relative to the sheath between an extended position and a retracted position while a balloon wire or guidewire extends through the exchange port. When the dilator is withdrawn in a proximal direction into the sheath, it provides a space within the lumen of the distal end of the sheath to accommodate a filter or other device retrieved by the wire. The dilator includes a tapered tip, which allows the device to be inserted between the stent and the vasculature for retrieval of devices distal to the stent. The tip may be a soft or hard pliable thermoplastic, metal such as stainless steel, or ceramic and will have a radius, which averts snagging on the stent and vasculature. The inner diameter of the tip is sized to control the clearance between the tip inner diameter and the guidewire outer diameter, which aids in operation of the device. The catheter assembly preferably includes a hydrophilic and/or a lubricious coating applied to the dilator tip and also preferably applied to the sheath from tip to the exchange port.
|
FIELD OF THE INVENTION The present invention relates to catheters used for retrieving, positioning, or repositioning endoluminal devices located distal or adjacent to a stent or other previously implanted device. BACKGROUND OF THE INVENTION The field of endovascular surgery is rapidly becoming an alternative to more traditional surgeries such as carotid endarterectomy, coronary artery bypass grafting, aortic aneurysm repair, and vascular grafting. Percutaneous intervention is becoming the primary means for revascularization in many such procedures. Distal embolization of friable debris from within the diseased conduit remains a risk of endovascular surgery, potentially involving complications such as myocardial infarction and ischemia. Devices such as balloon catheters and embolic filters have been used to control and remove embolic debris dislodged from arterial walls during endovascular procedures, distal to an interventional procedure site. Percutaneous introduction of these devices typically involves access via the femoral artery lumen of the patient's groin vasculature. An introducer sheath may then be inserted in the wound, followed by a guide catheter that is advanced to the site to be treated. A guidewire is usually introduced into the lumen of the vasculature and advanced distally, via manipulation by the clinician, to cross the lesion or area of treatment. Then a catheter containing the device(s) may be employed to traverse the length of the guidewire to the desired deployment location. Once the distal protection device is deployed, the lesion or stenosis is available for treatment. A common practice for treating the lesion or stenosis is to deploy a stent at the target location to increase the lumen size of the vessel and maintain or increase patency. When feeding a guidewire through the lumen of a stent, there is a possibility that the tip of the wire will become diverted and/or ensnared by the stent. This possibility increases with increasing vessel tortuosity. This problem has been addressed through the use of a soft, flexible, floppy tip at the distal end of the wire to improve steerability and reduce the possibility of engaging the stent or peripheral vasculature. However, a flat-tipped catheter advanced over a guidewire with an inside diameter larger than the outside diameter of the guidewire, presents a sharp edge to the vessel or stent at the point of tangential contact. The exposure of this edge increases with vessel tortuosity and with an increase in differences between the guidewire outside diameter and catheter inside diameter. Embolic filters and balloons are often deployed by traversing the lesion being treated and deploying the device distally. If a balloon wire or embolic filter becomes caught in the patient's vasculature or is otherwise prevented from removal by a stent, such as the device becoming entrapped within the struts of a stent, then the clinician is typically required to perform higher risk procedures to retrieve them. These include subjecting the device to greater retrieval forces, and removal through invasive surgical techniques. The former increases the risk of the device becoming detached from its guidewire or catheter, whereas the latter exposes the patient to the increased risks of open surgical extraction. Successful retrieval of these devices in situations other than those originally anticipated, without intimal dissection, plaque, hemorrhage, or vessel occlusion, is an important advancement in the field of interventional endovascular surgery. SUMMARY OF THE INVENTION A retrieval catheter assembly is described that may be operated by a single clinician and upon delivery will neither permanently displace a previously deployed stent nor cause undue trauma to the vascular lumen or lesion. The retrieval catheter assembly will enable a tubular retrieval sheath to be advanced over a wire between the outside diameter of a deployed stent and the vessel wall, or over a guidewire through the lumen of a stent and retrieve various devices, e.g., filters, balloons, etc. distal to the stent. The retrieval catheter may also enable a tubular sheath to be directed through the sidewall of a stent. The retrieval catheter assembly comprises a sheath having a balloon wire or guidewire exchange port through the sidewall of the sheath and a dilator, which is positioned in the sheath lumen. The sheath has a body with relatively stiff proximal and distal sections and with a flexible middle section, which aids in the operation of the device. The dilator is adapted to slide axially relative to the sheath between an extended position and a retracted position while a balloon wire or guidewire extends through the exchange port. When the dilator is withdrawn in a proximal direction into the sheath, it provides a space within the lumen of the distal end of the sheath to accommodate a filter or other device retrieved by the wire. The dilator includes a tapered tip, which allows the device to be inserted between the stent and the vasculature for retrieval of devices distal to the stent. The tip may be a soft or hard pliable thermoplastic, metal such as stainless steel, or ceramic and will have a radius, which averts snagging on the stent and vasculature. The inner diameter of the tip is sized to control the clearance between the tip inner diameter and the guidewire outer diameter, which aids in operation of the device. The catheter assembly preferably includes a hydrophilic and/or a lubricious coating applied to the dilator tip and also preferably applied to the sheath from tip to the exchange port. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a perspective view of the catheter assembly. FIG. 1B is a longitudinal cross-sectional view of the catheter assembly tip with guidewire threading tube. FIG. 1C is a longitudinal cross-sectional view of the catheter assembly tip and relative position of the cooperative opening region during a first stage of device retrieval. FIG. 1D is a longitudinal cross-sectional view of the catheter assembly tip and relative position of the cooperative opening region during a second stage of device retrieval. FIG. 1E is a longitudinal cross-sectional view of the catheter assembly tip configured to have a slit type cooperative opening extending to the most distal tip of the assembly. FIG. 2A is a cross-sectional view of a vascular filter in situ, distal to a vascular lesion. FIG. 2B is a cross-sectional view of a vascular filter in situ, distal to a vascular lesion that has been covered by a deployed stent. FIG. 2C is a cross-sectional view of a retrieval catheter of prior art. FIG. 3A is a cross-sectional view of one embodiment of this invention showing a step in a method of using the retrieval device in a vascular filter retrieval procedure. FIG. 3B is a cross-sectional view of one embodiment of this invention showing a second step in a method of using the retrieval device in a vascular filter retrieval procedure. FIG. 3C is a cross-sectional view of one embodiment of this invention showing a third step in a method of using the retrieval device in a vascular filter retrieval procedure. FIG. 3D is a cross-sectional view of one embodiment of this invention showing a fourth step in a method of using the retrieval device in a vascular filter retrieval procedure. FIG. 4A is a cross-sectional view of an occlusion balloon with the balloon wire positioned between the deployed stent and the vasculature. FIG. 4B is a cross-sectional view of a retrieval catheter of prior art. FIG. 4C is a cross-sectional view of one embodiment of the present retrieval catheter showing a step in a method of using the retrieval device in a balloon retrieval procedure. FIG. 5 is perspective view of one embodiment of the present retrieval catheter showing the retrieval catheter exiting the lumen of a previously placed stent through the sidewall of the stent. DETAILED DESCRIPTION OF THE INVENTION As noted above, this catheter assembly includes a sheath, dilator and guidewire. FIG. 1A is a perspective view of catheter assembly 20, having a sheath 22, dilator 24, guidewire threading tube 25, and guidewire 26. Guidewire threading tube 25 may be constructed from a variety of polymeric materials such as polyimide. Guidewire threading tube 25 is provided to aid in the insertion of the guidewire 26 through sheath slot 30 and dilator slot 46 (per FIG. 1B), prior to use in a patient. This threading tube 25 is typically removed from catheter assembly 20 prior to insertion into a patient. Also shown in FIG. 1A is the proximal end of the dilator 24, or dilator hub 28 extending from the luer hub 29. FIG. 1A additionally depicts the distal section 23 of catheter assembly 20. FIGS. 1C-1E are longitudinal cross-sections of distal section 23 showing a sheath 22, dilator 24, dilator lumen 27, sheath slot 30, dilator slot 46, and guidewire 26. Note the relative distal movement of sheath 22 and sheath slot 30 with respect to dilator 24 and dilator slot 46. The sheath 22 and hubs 28 and 29 may comprise conventional medical grade materials such as nylon, acrylanitrile butadiene styrene, polyacrylamide, polycarbonate, polyethylene, polyformaldehyde, polymethylmethacrylate, polypropylene, polytetrafluoroethylene, polytrifluorochlorethylene, polyether block amide or thermoplastic copolyether, polyvinylchloride, polyurethane, elastomeric organosilicon polymers, and metals such as stainless steels and nitinol. The sheath 22 or dilator 24 may contain either radiopaque markers or contain radiopaque materials commonly known in the art. In one embodiment, the catheter assembly 20 may be used to retrieve a previously placed vascular filter 32. FIG. 2A illustrates a vascular filter 32 with filter wire 34 placed within the vasculature 36, distal to a lesion 37. In this application, a stent 38 is placed over the vascular lesion 37 creating a rough, tortuous region across which vascular filter 32 is to be retracted as shown in FIG. 2B. FIG. 2C depicts a retrieval catheter 40 of prior art. Note the relatively inflexible catheter shaft and the inability of the catheter 40 to maintain a concentric position within the lumen of the catheter shaft of filter wire 34. Also note the significant difference between catheter 40 inner diameter and filter wire 34 outer diameter, creating an opening which provides an opportunity for catheter 40 to engage with the stent 38. FIGS. 3A through 3D show sequential cross-sectional views of the retrieval catheter in use. In these figures, the catheter assembly 20 is used to retrieve a previously placed vascular filter 32. FIG. 3A illustrates an embodiment of the present retrieval catheter with sheath 22 and dilator 24 navigating the rough, tortuous region through the stent 38 toward the previously placed vascular filter 32. The sheath 22 may be constructed with varying stiffness along the length. Methods of construction to achieve variable stiffness in a sheath component are well known in the art and include varying cross sectional profile dimensions and/or wall thickness, changing the hardness or modulus of the sheath material, braid modification, and including the use of a removable stylet or stiffening wire. Additional methods of achieving variable stiffness in a sheath component are generally taught by U.S. Pat. No. 6,858,024 and U.S. Pat. Appl. No. 2007/0088323 A1. The sheath 22 may be made with an outer diameter that would vary depending on targeted vascular size. For example, a sheath used with a 0.36 mm guidewire would have an outer diameter that ranges from about 1.57 mm to 1.62 mm. The sheath 22 inner diameter would also vary with application and for use with a 0.36 mm guidewire typically ranges from about 1.22 mm to 1.27 mm. The sheath 22 includes a slot or aperture 30 functioning as a cooperative opening or exchange port through the sidewall of the sheath. The slot 30 may be formed through the side wall of the sheath 22 by methods known in the art which may include skiving by hand with a straight razor or cutting with a suitable tool. One or both ends of slot 30 may be formed to be perpendicular to the longitudinal axis of sheath 22. Alternately, one or both ends may be formed to have a taper to reduce the angle between the proximal end of slot 30 and the guidewire 26. As shown in FIG. 3A, the slot 30 may be a formed to have a length 42 that would vary with application but would preferably range from about 0.20 mm to 0.38 mm. Slot 30 may have a width 44 suitable to provide adequate clearance between the slot 30 and a guidewire 26 or balloon wire. Alternately, slot 30 may be formed as a slit thus providing an interference fit between the guidewire 26 or balloon wire and the slit walls. Slot 30 may also be configured with features to provide positive tactile feedback to a user during device use. These may include such features slot 30 being formed to have a barbell shape that provides stops at the proximal and distal ends of slot 30 for securing guidewire 26 or a balloon wire. Slot 30 may also be provided with rough surfaces or serrations along the edge the of slot 30 to provide enhanced tactile feedback. The slot 30 may be cut at a distance from the distal end of the sheath from about 1 cm to about 50 cm from the distal end of the sheath 22 depending on the specific design requirements. Preferably, the range would be from about 5 cm to about 31 cm from the distal end of the sheath 22. The most preferred range would be from about 25 cm to about 32 cm from the distal end of the sheath 22. The outer surface of sheath 22 may be provided with a hydrophilic/lubricious coating. The coating may be applied to the entire outer surface of the sheath. Most preferably, the coating may be applied from the most distal end continuing to about the slot 30 or aperture. The inner surface of sheath 22 component may be provided with a hydrophilic/lubricious coating. The coating may be applied to the entire inner surface of the sheath 22. Preferably, the coating may be applied to the distal most 40 cm of the sheath 22. Most preferably, the coating may be applied to the distal most 30 cm of the sheath 22. The coating may be any biocompatible polymer lubricant as commonly known in the art. Dilator 24 is typically formed from a lubricious plastic material such as polytetraflouroethylene, polyethylene, polyether block amide or thermoplastic copolyether to provide a high degree of lubricity in the blood vessel as well as with respect to movement of the sheath 22 over the dilator 24. Dilator 24 may also be formed of a lubricious plastic material in combination with a metal hypo tube. Dilator 24 is typically provided with a hub 28 at its proximal end and is of a length slightly greater than the length of the catheter assembly so that when the hub 28 of the dilator is advanced fully distally against the proximal end of catheter hub 29, the tip of dilator 24 will project beyond the distal end of the catheter. Thus, the length of dilator 24 will depend on the length of the sheath 22. The tip of dilator 24 is considered to be the tapered portion located at the distal most tip of dilator 24. A length of about 1 cm for the tapered portion will be applicable to most applications but could range from about 1 mm to 5 cm. Dilator 24 may be made with an outer diameter sized to pass through the lumen of the sheath 22 with which it is intended to be and may be supplied in various sizes dependant on the application and catheter sheath inner diameter. A typical range of outer diameters for the intended application of retrieving a vascular filter or balloon would be from about 1.14 mm to 1.19 mm. The clearance between a guidewire 26 or balloon wire and the lumen of dilator 24 is relatively small and would vary dependant on intended use. For the intended application involving use over a guidewire, a typical inner tip diameter would be from about 0.38 mm to 0.43 mm. Alternately, dilator 24 may be used with a balloon wire where a typical inner tip diameter would be from about 0.48 mm to 0.53 mm. Dilator 24 has a lumen 27 adapted for passage of a guidewire or balloon wire. Diameters of dilator lumens 27 will vary with intended use. A typical dilator lumen 27, suitable for use with a guidewire 26, would be from about 0.48 mm to 0.53 mm. Alternately, dilator 24 may be made with a lumen 27 suitable for balloon wires, typically ranging from about 0.61 mm to 0.66 mm. Dilator 24 may have a tip made of pliable thermoplastic such as Pebax® (polyether block amide or thermoplastic copolyether from Arkema, Beaumont Tex. 77704) or metal such as stainless steel, nitinol or any other material with appropriate stiffness, hardness and other properties suitable for use in the human body. The dilator tip may alternately be constructed of a combination of a biocompatible metal and thermoplastic in a variety of ways. The tip may also be of composite metal or ceramic and/or polymer construction. As shown in FIG. 3A (and similar to the slot 30 through the sidewall of sheath 22), dilator 24 has a slot 46 through the sidewall of the dilator 24. The dilator slot 46 may be formed through the sidewall of the dilator 24 by methods well known in the art which may include skiving by hand with a straight razor cutting with a suitable tool. One or both ends of dilator slot 46 may be formed to be perpendicular to the longitudinal axis of dilator 24. Alternately, one or both ends may be formed to have a taper to reduce the angle between the proximal end of dilator slot 46 and the guidewire 26. The dilator slot 46 may have a length 48 extending from about 1 cm proximal to the dilator tip to the distal end of the luer hub 29. Preferably, the dilator slot 46 may extend from about 1 cm proximal to the dilator tip to about 100 cm proximal to the tip. Most preferably, the dilator slot 46 may extend from about 1 cm proximal to the dilator tip to about 33 cm proximal to the tip. In still another embodiment, dilator slot 46 (particularly if configured as a slit as described below) may extend from the tip to about, for example, 33 cm proximal to the tip. Dilator slot 46 may have a width 48 suitable to provide adequate clearance between the dilator slot 46 and a guidewire 26 or balloon wire. Alternately, dilator slot 46 may be formed as a slit thus providing an interference fit between the guidewire 26 or balloon wire and the slit walls. Dilator slot 46 may also be configured with features to provide positive tactile feedback to a user during device use. These may include such features dilator slot 46 being formed to have a barbell shape that provides stops at the proximal and distal ends of dilator slot 46 for securing guidewire 26 or a balloon wire. Dilator slot 46 may also be provided with rough surfaces or serrations along the edge the of dilator slot 46 to provide enhanced tactile feedback. FIG. 3B shows the distal end of the catheter assembly 20 positioned in vasculature 36 in close proximity to a previously placed vascular filter 32. The catheter assembly 20 was advanced over the previously placed vascular filter wire 34. Note that dilator 24 protrudes from the sheath 22. As shown in FIG. 3C, the dilator 24 is retracted into sheath 22 in the direction as shown by arrow 50. Note the axial sliding movement of slot 30 and dilator slot 46 with respect to slot 30 of sheath 22. As shown in FIG. 3D, the dilator 24 remains retracted into the sheath 22. Sheath 22 is advanced in the direction as shown by arrow 52 thereby collapsing the vascular filter 32. After the filter 32 has been collapsed and contained within the sheath 22, the catheter assembly 20 is withdrawn from the target site. FIGS. 4A through 4C show sequential cross-sectional views of a retrieval catheter in use retrieving a balloon 54. FIG. 4A shows a stent 38 deployed over a balloon 54 and balloon wire 56, trapping the balloon 54 and/or balloon wire 56 between the stent 38 and vasculature 36. FIG. 4B depicts a retrieval catheter 40 of prior art. Note the relatively inflexible catheter shaft and the inability of the catheter 40 to maintain a concentric position within the lumen of the catheter shaft of balloon wire 56. FIG. 4C illustrates an embodiment of the invention with sheath 22 and dilator 24 navigating the rough tortuous region between the stent 38 and the vasculature 36 toward the trapped balloon 54. The remainder of the balloon retrieval procedure is similar to the procedure described in FIGS. 3B through 3D. The present invention may also be used to position or reposition a device located distal or adjacent to a stent or other previously implanted device. FIG. 5 depicts an embodiment of the present invention with sheath 22 and dilator 24 exiting the lumen of a previously placed stent 38 through the sidewall of the stent 38. This embodiment could be used to deploy or reposition an endoluminal device into the branch vasculature. The same embodiment could alternately be used to retrieve an endoluminal device from branch vasculature. EXAMPLES To construct a sheath, a 1.24 mm PTFE coated mandrel was loaded with a 1.29 mm inner diameter etched PTFE liner (1.29 mm inner diameter.×0.02 mm thick wall) and secured. A braided sleeving (0.25 mm×0.76 mm stainless steel flat wire, 2 over 2 under, 50 ppi) was loaded and secured at the proximal end of mandrel. The braid was stretched to the distal end of the mandrel and carefully trimmed to length with scissors so that the ends of the wires were uniform. Trimming of the braid length may be achieved with any suitable cutting or trimming tool. A marker band (platinum/iridium, 1 mm width minimum, inner diameter 14.7 mm, 0.25 mm minimum thickness) was slid onto the assembly from the proximal end of the loaded mandrel to the distal end. The marker band was carefully brought up to the end of the braid so that the marker band covered the end of the braid and so that no ends of wires were showing at the marker band. The location of the marker band should be from about 5.08 cm to 6.35 cm from the distal end of the mandrel. A hand crimper tool was used to secure the marker band. The braid was then stretched from the proximal end of the mandrel and re-secured. To pre-assemble the proximal and distal body stock components of the sheath, the proximal component (Pebax® 7233, 72 durometer and 1.57 mm inner diameter and 0.10 mm wall, gold pigment) was cut to about 125 cm and the distal body stock component (Pebax® 5533, 55 durometer and 0.157 cm inner diameter and 0.10 mm wall, grey pigment) was cut to about 32.5 cm. The distal body stock component was flared with the end of a pair of small tweezers so that it would slide over the proximal body stock component. The distal and proximal components were loaded onto a 0.15 mm PTFE mandrel (nonporous PTFE) and the two components were overlapped by 1 mm. A 2.54 cm long length of FEP heat shrink (EP4587-10T, Zeus, Orangeburg, S.C. 29116) was positioned over the center of the 1 mm overlap of the two body stock components and a heat gun was used to bond the two components together. The FEP heat shrink tube was removed after the bond had cooled. The pre-assembled body stock component was loaded onto the proximal end of the 1.24 mm PTFE coated mandrel bringing the end of the pre-assembled body stock component to within 2 cm to 3 cm past the marker band. A heat shrink tube (EP4587-10T FEP 1.9 mm minimum expanded inner diameter) was loaded over the entire assembly with the end of the heat shrink tube reaching the end of the pre-assembled body stock component distal end. The two ends were bonded together with a heat gun. The assembly was heated in a convection heat shrink reflow oven. The assembly was allowed to air cool, the heat shrink tube was removed and the ends were trimmed with a razor. The entire assembly was removed from the mandrel. The assembly was cut to a length of about 142 cm and the tip was trimmed. A hole was hand cut at about 29.7 cm from the distal end of the sheath. A female luer hub (Qosina part No. 41426 Qosina, Edgewood, N.Y. 11717) was bonded to the proximal end with adhesive (Loctite® 4011 Adhesive, Henkel Corp., Rocky Hill, Conn. 06067). A stock dilator (Pebax® 7233, light grey pigment, 0.48 mm inner diameter×0.12 mm outer diameter) was tipped down to 0.36 mm inner diameter and 0.66 mm outer diameter with a radio frequency tipping machine (Ameritherm Inc., Scottsville, N.Y. 14546). The dilator was then cut to about 152 cm in length. Any appropriate cutting method may be used. An 4.0 cm slot was hand skived in the dilator starting at about 27.2 cm from the distal end of the dilator. The proximal end of the dilator was heat flared to form a mechanical anchor. A female luer hub (Qosina part. No. 64018) was bonded onto the dilator proximal end with Loctite® 3311 Adhesive. To assemble the catheter assembly 20, a hemostasis valve (part No. RV0317-000, Qosina part No. 88416) was attached to the hub of the dilator 24. With the aid of a 0.36 mm guidewire, the sheath 22 and dilator 24 components were assembled and guidewire threading tube 25 (Phelps Dodge part No. Polyimide EP4649-10Z 0.38 mm inner diameter×0.47 mm outer diameter, Phelps Dodge HPC, Trenton, Ga. 30752) was installed in the assembly. The catheter assembly 20 was masked to expose the proximal and distal ends. A flexible mandrel (0.46 mm outer diameter) was inserted into the distal end of the assembly until it exited the cooperative opening 30. The loaded assembly was then placed into a vacuum plasma system. The entire assembly was plasma treated to enhance attachment of the polymer lubricant. The catheter assembly 20 was removed from plasma system. The sheath 22 and dilator 24 components of the catheter assembly 20 were then dip coated with a biocompatible polymer lubricant to reduce friction. The catheter assembly 20 with lubricious coating was then heat cured. The flexible mandrel was removed and catheter assembly 20 was then placed in a protective polymer coil and packaged for shipment. While particular embodiments of the present invention have been illustrated and described herein, the present invention should not be limited to such illustrations and descriptions. It should be apparent that changes and modifications may be incorporated and embodied as part of the present invention within the scope of the following claims.
|
A
|
A61
|
A61M
|
29
|
00
|
|||
11651913
|
US20080164021A1-20080710
|
Methods and systems for fracturing subterranean wells
|
ACCEPTED
|
20080625
|
20080710
|
[]
|
E21B4326
|
["E21B4326"]
|
7516793
|
20070110
|
20090414
|
166
|
308100
|
67634.0
|
BATES
|
ZAKIYA
|
[{"inventor_name_last": "Dykstra", "inventor_name_first": "Jason D.", "inventor_city": "Addison", "inventor_state": "TX", "inventor_country": "US"}]
|
New methods and systems for subterranean fracturing for hydrocarbon wells. A plan of the fracture propagation and in-fracture proppant distribution is used with a real-time model of the status of the fracture dimensions and in-fracture proppant concentration to automatically control flow rates and properties of a fracturing fluid flow stream being used to induce and prop the fracture. Real-time measurements of the status of the fracture are made using surface and/or down-hole sensors. Real-time control over the flow rate and properties of a fracturing fluid flow stream are made by manipulating the fracturing fluid supply equipment. Real-time modifications of the fracturing model are made by comparing fracture sensor measurements of actual fracture dimensions to the predicted dimensions, and then adjusting the model for inaccuracies. Real-time updates to the fracturing plan are made by comparing actual fracture and propping results to desired results, and then adjusting to achieve optimal results.
|
1. A method for performing fracturing on a well, comprising the actions of: (a) fracturing, in accordance with a fracturing model and a fracturing plan, while monitoring inputs used to estimate fracturing progress; (b) automatically modifying said fracturing model from time to time, as said monitoring action indicates that said fracturing model may be inaccurate; and (c) automatically modifying said fracturing plan, in dependence on said action (b). 2. The method of claim 1 wherein said fracturing plan is a time series of desired results for a subterranean fracturing process for a hydrocarbon well comprising: (i) target three-dimensional spatial coordinates defining the boundaries and interior space of a subterranean fracture, and (ii) the target volume of said fracture occupied by a proppant at said spatial coordinates. 3. The method of claim 1 wherein said fracturing plan is a time-based description of desired results for a subterranean fracturing process for a hydrocarbon well comprising: (i) the target propagation direction of a fracture from said well; (ii) at least two spatial dimensions defining the target geometry of said fracture as it propagates; and (iii) the target volume fraction of said fracture occupied by a proppant for at least some locations within said fracture as it propagates. 4. The method of claim 2 wherein said fracturing plan is further comprised of: (iii) target volume of said fracturing fluid pumped into said fracture; and (iv) the target pressure of said fluid at least at some spatial coordinates within said fracture and/or said well. 5. The method of claim 3 wherein said fracturing plan is further comprised of: (iv) target volume of said fracturing fluid pumped into said fracture; and (v) the target pressure of said fracturing fluid at some locations within said fracture and/or said well. 6. The method of claim 1 wherein said model comprises: (i) three-dimensional spatial coordinates defining the boundaries and interior space of the current state of a subterranean fracture, and (ii) the volume of said fracture currently occupied by a proppant at said spatial coordinates. 7. The method of claim 1 wherein said model comprises: (i) the current propagation direction of a subterranean fracture from a hydrocarbon well under-going a fracturing process; (ii) at least two spatial dimensions defining the current status of said fracture; and (iii) the volume fraction of said fracture currently occupied by a proppant for at least some locations within said fracture as it propagates. 8. The method of claim 6 wherein said model is further comprised of: (iii) actual volume of said fracturing fluid pumped into said fracture; and (iv) actual pressure of said fluid at least at some locations within said fracture. 9. The method of claim 7 wherein said model is further comprised of: (iv) actual volume of said fracturing fluid pumped into said fracture; and (v) actual pressure of said fluid at least at some locations within said fracture. 10. The method of claim 1 wherein said model receives sensed measurements of the status of the fracture dimensions from surface, down-hole, and/or off-set sensors. 11. The method of claim 1 wherein the properties of the fracturing fluid flow stream being used to conduct said fracturing are selected from the group consisting of volumetric flow rate, mass flow rate, temperature, pressure, viscosity, pH, percent proppant in the fluid, concentration of at least one chemical that modifies the rheologic properties of said fracturing fluid, and the concentration of a least one chemical that modifies the pH of said fracturing fluid, or combinations thereof. 12. The method of claim 1 wherein target down-hole properties of the fracturing fluid flow stream being used to conduct said fracturing comprises at least one transform that calculates real-time values for said properties by summing: (i) calculated values for each of said properties using a model of fracture propagation to achieve current said plan; and (ii) calculated adjustments for each of said properties based on the error between said plan and said current state of the fracture. 13. A subterranean fracturing process system for a hydrocarbon well, comprising: at least one pump for delivering a fracturing fluid flow stream into a hydrocarbon well; surface and/or down-hole actuators which jointly control the down-hole-values of one or more properties of said flow stream; and a control system which controls said actuators and said pump in relation to a subterranean fracturing plan using a fracturing model, to govern said down-hole values; wherein said control system further automatically modifies said fracturing model from time to time, when at least one monitoring action indicates that said fracturing model may be inaccurate; and wherein said control system automatically modifies said fracturing plan to optimize the results of the fracturing process. 14. The system of claim 13 wherein said fracturing plan is a time series of desired results for operating said subterranean fracturing process system comprising: (i) the target three-dimensional spatial coordinates defining the boundaries and interior space of a fracture, and (ii) the target volume of said fracture occupied by a proppant at said spatial coordinates. 15. The system of claim 13 wherein said fracturing plan is a time-based description of desired results for operating said subterranean fracturing process system comprising: (i) the target propagation direction of a fracture from said well; (ii) at least two spatial dimensions defining the target geometry of said fracture as it propagates; and (iii) the target volume fraction of said fracture occupied by a proppant for at least some locations within said fracture as it propagates. 16. The system of claim 14 wherein said desired fracturing plan is further comprised of: (iii) target volume of said fracturing fluid pumped into said fracture; and (iv) the target pressure of said fluid at least at some spatial coordinates within said fracture. 17. The system of claim 15 wherein said desired fracturing plan is further comprised of: (iv) target volume of fracturing fluid pumped into said fracture; and (v) the target pressure of said fracturing fluid at some locations within said fracture. 18. The system of claim 13 wherein said properties of said fracturing fluid flow stream are selected from the group consisting of volumetric flow rate, mass flow rate, temperature, pressure, viscosity, pH, percent proppant in the fluid, concentration of at least one chemical that modifies the rheologic properties of said fracturing fluid, and the concentration of a least one chemical that modifies the pH of said fracturing fluid, or various combinations thereof. 19. The system of claim 13 wherein said control system determines target down-hole properties of said fracturing fluid flow stream by using at least one transform that sums: (i) calculated values for each of said properties using a model of fracture propagation to achieve current said plan; and (ii) calculated adjustments for each of said properties based on the error between said plan and said current state of the fracture.
|
<SOH> BACKGROUND AND SUMMARY OF THE INVENTION <EOH>The present application relates to methods and systems for conducting the hydraulic fracturing of subterranean wells, and more particularly to the control of processes related to subterranean hydraulic fracturing used to stimulate the production of hydrocarbon wells, and most especially to real-time and automatic control of fracture propagation and placement of proppant therein. The following paragraphs contain some discussion, which is illuminated by the innovations disclosed in this application, and any discussion of actual or proposed or possible approaches in these paragraphs does not imply that those approaches are prior art.
|
<SOH> BACKGROUND AND SUMMARY OF THE INVENTION <EOH>The present application relates to methods and systems for conducting the hydraulic fracturing of subterranean wells, and more particularly to the control of processes related to subterranean hydraulic fracturing used to stimulate the production of hydrocarbon wells, and most especially to real-time and automatic control of fracture propagation and placement of proppant therein. The following paragraphs contain some discussion, which is illuminated by the innovations disclosed in this application, and any discussion of actual or proposed or possible approaches in these paragraphs does not imply that those approaches are prior art.
|
BACKGROUND AND SUMMARY OF THE INVENTION The present application relates to methods and systems for conducting the hydraulic fracturing of subterranean wells, and more particularly to the control of processes related to subterranean hydraulic fracturing used to stimulate the production of hydrocarbon wells, and most especially to real-time and automatic control of fracture propagation and placement of proppant therein. The following paragraphs contain some discussion, which is illuminated by the innovations disclosed in this application, and any discussion of actual or proposed or possible approaches in these paragraphs does not imply that those approaches are prior art. Background: Hydrocarbon Formation Fracturing and Propping Subterranean hydraulic fracturing is conducted to increase or “stimulate” production from a hydrocarbon well. To conduct a fracturing process, high pressure is used to pump special fracturing fluids, including some that contain propping agents (“proppants”) down-hole and into a hydrocarbon formation to split or “fracture” the rock formation along veins or planes extending from the well-bore. Once the desired fracture is formed, the fluid flow is reversed and the liquid portion of the fracturing fluid is removed. The proppants are intentionally left behind to stop the fracture from closing onto itself due to the weight and stresses within the formation. The proppants thus literally “prop-apart”, or support the fracture to stay open, yet remain highly permeable to hydrocarbon fluid flow since they form a packed bed of particles with interstitial void space connectivity. Sand is one example of a commonly-used proppant. The newly-created-and-propped fracture or fractures can thus serve as new formation drainage area and new flow conduits from the formation to the well, providing for an increased fluid flow rate, and hence increased production, of hydrocarbons. To plan a fracture's height, length, and width, many factors are considered, including the characteristics of the producing formation to be fractured, such as its size and geometry, its mechanical properties, its permeability to fluid flow, and any near-by water-bearing formations. In general, an optimum result of a fracture includes balancing the width, length, and height of the fracture with the fluid permeability of the formation and fluid conductivity of the propped fracture. To plan a fracturing fluid pumping process to create a targeted fracture, fracturing models can be used which predict the propagation of fractures through a formation of given mechanical properties in relation the pumped volume, pumping rate, and rheologic properties of the fracturing fluid being used. Two-dimensional models such as the Khristianovic-Geertsma-de-Klerk model and the Perkins-Kern-Nordgren model are well-known to those skilled in the art of fracturing. See Chapter 1 of “Mechanics of Hydraulic Fracturing” by Ching H. Yew, 1997, by Gulf Publishing Company, Houston, Tex., ISBN 0-88415-474-2, which is hereby incorporated by reference. Three dimensional fracturing planning models are also well-known to those skilled in the art of fracturing. See Chapter 5 of “Recent Advances in Hydraulic Fracturing” by John L. Gidley, Stephen A. Holditch, Dale E. Nierode, and Ralph W. Veatch Jr., Society of Petroleum Engineers Monograph Series, Richardson, Tex., 1989. To begin a fracturing process, at least one perforation is made at a particular down-hole location through the wall of the well casing to provide access to the formation for the fracturing fluid. Perforation technologies are well known to those skilled in the art of hydrocarbon well technology. The direction of the perforation attempts to determine at least the initial direction of the fracture. A first “mini-fracture” test is usually conducted in which a relatively small amount of proppant-free fracturing fluid is pumped into the formation to determine and/or confirm at least some of the properties of the formation, including the permeability of the formation itself. Accurately knowing the permeability allows for a prediction of the fluid leak-off rate at various pressures, whereby the amount of fracturing fluid that will flow into the formation can be considered in establishing a pumping and proppant schedule. Thus, the total amount of fluid to be pumped down-hole is at least the sum of the hold-up of the well, the amount of fluid that fills the fracture, and the amount of fluid that leaks-off into the formation during the fracturing process itself. Leak-off rate is an important parameter because once proppant-laden fluid is pumped into the fracture, leak-off can increase the concentration of the proppant in the fracturing fluid beyond a target level. Data from the mini-fracture test then is usually used by experts, either on-site or communicating from a distance, to confirm or modify the original desired target profile of the fracture and the process used to achieve the fracture. U.S. patent application Ser. No. 11/031,874, to Mohamed Soliman and David Adams, entitled “Method and System for Determining Formation Properties Based on Fracture Treatment”, published on Jul. 13, 2006, teaches mini-fracture technology, and is hereby incorporated by reference. Fracturing then begins in earnest by first pumping proppant-free fluid into the well-bore or through tubing. The fracture is initiated and begins to grow in height, length, and/or width. This first proppant-free stage is usually called the “pre-pad” and consists of a low viscosity fluid. A second fluid pumping stage is usually then conducted of a different viscosity proppant-free fluid called the “pad.” At a particular time in the pumping process, the proppant is then added to the fracturing and propping flow stream using a continuous blending process, and is usually gradually stepped-up in proppant concentration. Too high a concentration of proppant can lead to an undesirable and premature “screen-out” in which the solids concentration within the fracture becomes so high that the pumping pressure exceeds the design limits of the system. In essence, the proppant plugs the fracture and stops the fracturing process. The process must sometimes be stopped because in many situations, continuing pumping will damage surface equipment or the well casing itself, e.g. rupturing the well casing. In other situations, the proppant might collect at an obstruction or within a too-narrow of a fracture, resulting in screen-out as well. U.S. Pat. No. 6,935,424, to Lyle V. Lehman and Christopher A. Wright, entitled “Mitigating Risk by Using Fracture Mapping to Alter Formation Fracturing Process”, issued on Aug. 30, 2005, teaches aspects of proppant screen-out, and is hereby incorporated by reference. Another common problem for a fracturing process is that the current resulting fracture is of the wrong geometry, orientation, directional positioning, and/or dimensions, or tending to be of the wrong geometry, orientation, directional positioning, or dimensions. This type of problem can be related to the inconsistency of subterranean geologic formations such as variable rock or soil properties, variable formation dimensions, or the presence of natural faults or fractures. Those skilled in the art of fracturing usually conduct significant pre-fracturing studies such as the mini-fracture test or other investigative techniques. However, a mini-fracture treatment may be insufficiently conducted as to not reach out far enough from the well to detect, for example, a particular change in rock formations and properties. Those conducting fracturing processes can use mapping of the fracture geometry using, for example, tilt-meters. U.S. Pat. No. 6,935,424 also teaches aspects of fracture mapping. Another problem that can result during fracturing is that even though a fracture with correct geometry is formed, the fracture is not sufficiently propped, or is inconsistently propped. Thus, the fracture can fully or partially re-close once the hydraulic pressure is released. Or, the proppant is so unevenly distributed that it is not consistently held in place by the formation once the hydraulic pressure is released, i.e. the proppant is “unconsolidated.” So, once the well begins or resumes hydrocarbon flow after fracturing, the proppant can be swept-out of the fracture and carried back up the well in the hydrocarbon flow stream, and possibly damage or plug equipment. Thus, successful fracturing includes achieving desired fracture dimensions and a desired proppant distribution within the fracture. Because of the complexity of achieving both of these simultaneously, there is a need for real-time control of both fracture formation and proppant placement during a fracturing process to achieve total desired results. And, because of the rising cost of providing expert labor to conduct fracturing operations, there is a need for an automatic control method and system for conducting fracturing processes. Further, as the value of hydrocarbons continues to rise, there is an increasing need for reduction of risk of undesired results associated with fracturing. Methods and Systems for Fracturing Subterranean Wells The present application discloses methods and systems for conducting subterranean fracturing for hydrocarbon wells. Inputs from fracture sensors and/or fracturing fluid flow stream sensors are monitored and used to estimate the progress of the propagation of a subterranean fracture. The progress estimate is exploited in real-time to automatically manipulate surface and/or down-hole physical components providing fracturing and propping fluids to a hydrocarbon well. This can be advantageously implemented using a real-time model of the fracture and the proppant distribution therein to determine the error from the desired fracture dimensions and the error from the desired proppant distribution within the fracture. The errors can be used by control transforms to derive fracturing and proppant fluid set-points to be used to control processing equipment delivering the fluid. Real-time modifications of the fracturing model can be made by comparing fracture sensor measurements of actual fracture dimensions to the predicted dimensions, and then adjusting the model for inaccuracies. Real-time updates to the fracturing plan can be made by comparing actual fracture and propping results to desired results, and then adjusting to achieve optimal results. In some embodiments (but not necessarily all), the disclosed ideas are used to provide new fracturing and propping control methods and systems by sensing the status of the fracture propagation and automatically controlling the flow rates, compositions, and properties of fracturing and propping fluids. In some embodiments (but not necessarily all), the disclosed ideas are used to provide new fracturing and propping control methods and systems by modifying the desired fracture dimensions and desired proppant distribution in real time in response to an unforeseen fracturing and/or propping event or events. The disclosed innovations, in various embodiments provide one or more of at least the following advantages: Improved hydrocarbon production from a hydrocarbon well. Improved results of subterranean fracturing whereby the resulting fracture dimensions, directional positioning, orientation, and geometry, and the placement of a proppant within the fracture more closely resemble the desired results. Improved results when unforeseen events occur during a fracturing and propping process. Reduced dependency on human intervention and decision-making during hydrocarbon formation fracturing. BRIEF DESCRIPTION OF THE DRAWINGS The disclosed innovations will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference. FIG. 1 shows a preferred embodiment of the present innovations for a method for conducting a fracturing process consistent with the present application. FIG. 2 shows embodiments of desired fractures consistent with desired fracturing profiles of the present innovations. FIG. 2A shows an embodiment of the dimensional, directional positioning, orientation, and geometric attributes of a subterranean fracture. FIG. 2B shows embodiments of fractures consistent with the present innovations. FIG. 2C shows embodiments of further fractures consistent with the present innovations. FIG. 2D shows an embodiment of proppant placement within a fracture consistent with the present innovations. FIG. 2E shows embodiments of propped fracture widths consistent with the present innovations. FIG. 3 shows one embodiment of an exemplary subterranean hydrocarbon formation fracturing site, both surface and down-hole, to which the methods and systems of the present innovations can be applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment (by way of example, and not of limitation). FIG. 2 shows four embodiments of desired side-view profiles of resulting subterranean fractures, such as can be formed using the methods and systems of the present innovations, by way of examples, and not of limitations. In one embodiment, desired fracture profile 292 shows a side view of a subterranean fracture 294 emanating from perforation 293 in hydrocarbon well 290 that is perfectly contained vertically within pay zone (e.g. hydrocarbon-bearing formation or zone) 291. Any extension beyond the pay zone can be undesirable because no extra hydrocarbon-drainage area is opened-up for production and the fracturing time and fluid was wasted in achieving the non-paying fracture portion. In another embodiment, multiple horizontal pay zones or fractures 295 can be accessed and formed from the same hydrocarbon well with the resulting fractures perfectly vertically contained. In another embodiment 296, two or more perforations, e.g. multiple perforations, can be used to gain increased drainage from a single formation with the resulting formation perfectly contained. In another embodiment in a “horizontal” hydrocarbon well 297, one or more perforations can be used to create multiple fractures in a single formation or pay zone. The fractures shown in 297 are viewed end-wise rather than from a side view. FIG. 2A shows dimensional, orientation, directional positioning, and geometric attributes of fractures that can be controlled with the present innovations. Fracture 231 is a fracture oriented with its height in the vertical “z” direction 230, with reference to the surface of the earth. Such vertical orientation is the usual orientation resulting during a fracturing process. In another embodiment, fracture 231 can be oriented horizontally, such that its width 234 is in the vertical direction 230 with its length 235 along the “x” horizontal direction 232 or “y” horizontal direction 236 In another embodiment, fracture 231 can be tilted and not in-line with the orthogonal axes depicted in FIG. 2A. Width of fracture 234 is the smallest dimension of fracture 231, and usually on the order of magnitude of a fractions of a inch or inches. Length of fracture 235 is the dimension of growth generally away from the well. In one embodiment as shown of fracture 231, a desired fracture can have a generally constant height such that the height runs parallel to the top, and bottom, of a pay zone as shown in fracture 294 in FIG. 2. In other embodiments, the fracture can have a increasing or decreasing or variable height. In one embodiment as shown of fracture 231, a desired fracture can have a generally constant width. In other embodiments, the fracture can have a increasing or decreasing or variable width. In still other embodiments, the fracture can consist of multiple fractures that form a network. FIG. 2B shows top views and side views of embodiments of fractures that can be controlled or avoided using the methods and systems of the present innovations. In one embodiment, fracture 254A extends out of pay zone 252A along the vertical axis and can be considered undesirable because fracturing fluids are wasted. In one embodiment, fracture 254B undesirably extends vertically out of the pay zone 252B and into water bearing formation 260. In one embodiment fracture 254C forms in an unintended direction and out of the pay zone 252C but has a desirable vertical height. In one embodiment, the profile of fracture 254C can be considered undesirable. FIG. 2C shows further embodiments of fractures that can be controlled or avoided using the methods and systems of the present innovations. Fracture 254D formed horizontally instead of vertically but is completely within the pay zone 252D. In one embodiment, fracture 254D can be undesirable. Fracture 254E formed in a horizontally-tilted direction but is completely within the pay zone 252E. In one embodiment, fracture 254E can be undesirable. Fracture 254F formed in such a manner as one half of the fracture is vertical and the other half is oriented horizontally. In one embodiment, but still completely within pay zone 252F. In one embodiment, fracture 254F can be undesirable. FIG. 2D shows one embodiment of a desired proppant placement profile at a particular point in time of a fracturing and proppant process, by way of example and not of limitation, of proppant profiles that can be controlled by the methods and systems of the present innovations. In this embodiment, a single type of proppant can be distributed in varying concentration within the fracturing fluid down the length of a fracture 212. In this embodiment, no leak-off is assumed whereby the liquid portion of the fracturing fluids flow into the formation being fractured. Fracture 212 is shown extending from only one side of hydrocarbon well 208 for simplicity of illustration. Further, as fracturing and propping fluids are pumped down-hole, their direction of flow is shown as direction 210 within the fracture. For purposes of simple illustration, no other directions of flow are depicted, although many are possible. Additionally for purposes of simple illustration, the fracture is shown as constant height with no concentration gradient in the vertical dimension. As greater volumes of fracturing and propping fluids are pumped, fracture 212 grows in length. Time axis 218 shows the propagation of fracture over time. Assuming pure plug flow (e.g. no back-mixing in the opposite direction to direction 210) of the fluids, fracture zone 214A is the newest fracture zone but contains the fluid first pumped into the fracture. Likewise, fracture zone 214G is the oldest zone but contains the latest fluid. Fracturing and propping fluids pumping schedule 204 shows the variation of proppant concentration 202 in the fracturing flow stream over the duration in pumping time 206 (corresponding to time axis 218) in which fracturing and propping fluids 202A through 202G are pumped into well 208. Schedule 204 assumes a constant pumping rate for simplicity of illustration. The schedule 204 and the fracture 218 are pictorially aligned such that their time axes are directionally opposite to each other. Thus, fracturing fluid 204A, which has zero proppant, is the first to be pumped and it fills fracture zone 214A, which is the last to be formed. In one embodiment, the fracturing process depicted in FIG. 2B can be continued with a high degree of leak-off into the formation to the extent that virtually all of fracturing fluid 204A is leaked-off into the formation. In one embodiment, the process can be continued in such a manner as to not only have all of fracturing fluid 204A leak-off into the formation, but that just the correct amounts of the liquid portions of each of fracturing fluids 204B through 204G leak-off into the surrounding formation such that at the moment all of fracturing fluid 204A has leaked-off, the concentration of the proppant across all fluids 204B though 204G are equal. Then, at the moment the concentration of the proppant can be constant across fluids and zones, the hydraulic pressure is released and fracturing is halted. Then, the fracture can close upon itself and the liquid portion of the fracturing fluids can leak-off into the formation until the proppant consolidates to a bed such that the packed proppant bed supports or props the fracture. Assuming the fracture is of uniform width, the fracture would be uniformly propped with a uniformly packed bed of proppant down the length of fracture 212. Proppant placement profiles over time can incorporate different properties including variation of concentration of proppant in three dimensions in space, variation in the size, shape or chemical composition of the proppant, mechanical strength of the proppant, in composition of special ingredients in the propping fluids, in the time special ingredients have been mixed into the fluids, and in temperature of the fluid or fluids within the fracture. FIG. 2E shows embodiments of propped fracture widths that can be controlled or avoided with the methods and systems of the present innovations. A single grain of proppant 268, such as a grain of sand as can be used as a proppant, has a width 263. For simplicity of illustration, the width of all of the proppant particles is assumed constant. In a large fracture width 262 where the width of the fracture is significantly greater than the width of the proppant particles, the flow of a fracturing fluid containing proppant 268 can occur without the proppant collecting and causing a screen-out. In one embodiment, fracture 262 is desirable. In a small fracture width 264, the flow of a fracturing fluid containing proppant 268 is impeded because the proppant will collect and wedge in the small width fracture. In one embodiment, small width fracture 264 is undesirable. In a moderate width fracture 266, the flow of a fracturing fluid containing proppant 268 can occur within fracture 266 if the concentration of the proppant is low enough as to not collect to form screen-outs and the rheology of fluid is such that the proppant stays suspended and the fluid itself is not of an excessively high viscosity. In one embodiment, the methods and systems of the present innovations can simultaneously control the width of the fracture, the concentration of the proppant in the fracturing fluid, and the rheology of the fracturing fluid such that the fracturing process can be continue to be conducted without reaching a maximum operating pressure of the fracturing system whereby the desired fracture dimensions are increased, resulting in higher levels of drainage area being exposed to a hydrocarbon well. In one embodiment of the present innovations, proppant concentration as well as proppant particle diameter and shape can also be planned to be modified during a pumping schedule such as schedule 24. FIG. 3 shows a non-limiting embodiment of an exemplary subterranean hydrocarbon formation fracturing site 300 to which the methods and systems of the present innovations can be applied. Site 300 can be located on land or on or in a water environment. The embodiment will be described with reference to a land-based site. The site can contain one or more proppant stores 303 which contain one or more different proppant types or grades as would be known to one skilled in the art of proppant specification and design. The site can contain one or more fluid storage systems 304 for water, solvents, non-aqueous fluids, pad fluids, pre-pad-fluids, viscous fluids for suspending proppants, and liquid components to tailor-make fracturing fluids as would be known to open skilled in the art of fracturing fluid specification and design. The site can contain one or more special solid or liquid ingredient stores 306 which have specialized functions in the fracturing and propping processes. The flow actuation and control of proppants, fluids, and special ingredients can be controlled by activators 308, 308A, and 308B, respectively. Blender or blenders 310 can receive the proppants, the fluids and special ingredients to prepare fracturing and propping fluids in various proportions. Pump or pumps 314 can pump the fracturing and propping fluids down-hole into hydrocarbon well 316 beneath the surface of the earth 334. Components 303, 304, 306, 308, 308A, 308B, 310, 313, 314, 335, and 342 comprise surface components 330. Sensors 313 can monitor the fracturing and propping fluid flow rates, as well as the properties of the fluids, at positions either before or after pumps 314, or at both locations. Down hole tools 318 can act directly on the fracturing and propping fluids to control the values of the properties of the fluids as the fluids create and enter fracture 333, which is shown, for simplicity of illustration, in one direction from well 316. Down hole fluid property sensors 324 can measure the fluid property values as the fluids enter fracture 333. In-fracture fluid sensors 328 can sense the fluid property values of the fluid inside the fracture. Down hole fracture sensors 326 can sense the dimensions of fracture 333 from a down hole location. Off-set fracture sensors 340 can sense the dimensions of fracture 333 from an off set location down hole in a different well 338. Surface fracture sensors 335 can sense the dimensions of fracture 333 from the surface of the Earth. Control system 342 can be linked via signal links 336 to the listing of components as detailed in FIG. 2. Control system 342 can also be linked to external system 344 which in one embodiment can be an external data collection or supervisory control system. Control system 342 can contain various embodiments of the innovative control methods of the present application, such as the method of FIG. 1. Control system 342 can contain a desired subterranean fracture profile consistent with the present application. FIG. 1 shows a preferred embodiment of the fracturing methods of the present innovations. The method of FIG. 1 can be employed to conduct fracturing on a site such as fracturing site 300. The method of FIG. 1 can be employed as part of control system 342 or external system 344 to conduct fracturing on site 300. The method of FIG. 1 and system 300 can be used to conduct and control the fracturing and proppant process being used to create and prop fracture 333 within pay zone 334 in hydrocarbon well 316 using fracturing fluid flow stream 315. Fracturing plan 30 can be designed to achieve a particular increase in hydrocarbon production from an operating well as known to one skilled in the art of fracturing hydrocarbon production using techniques such as the mini-fracture test prior to actual fracturing, as described earlier. Fracturing plan 30 can also be designed for a newly created well to achieve a higher output upon start-up of the well had the fracturing operation not been conducted. Fracture profile matrix 31 can be outputted from fracturing plan stage 30 as fracturing plan 30A, where L(t) is the propagation function of the length dimension, L, over time, t, h(x, t) is the propagation function of the height dimension, h, over time and over the distance, x down the fracture length L, and w(x,t) is the propagation function of width dimension, w, over time and over x. SC(x,t) is the proppant placement function over time and over x. In one embodiment, the proppant placement function represents the concentration of the proppant at point x and time t. Conversion matrix 36 can use matrix 31 as a feed forward of the fracturing plan, as signal 30B, to determine a feed forward of the fracturing fluid flow stream properties such as flow rate, viscosity, and density, as signal 36A. Stage 36 can determine the fracturing fluid viscosity function μ(t), the fracturing fluid pumping flow rate function R(t), and fracturing fluid density function ρ(t). The fracturing plan matrix 31 as signal 30A can be compared against the current fracture state estimate matrix 48B in summing stage 32. The error 32A of the actual state versus the planned state can then be used to provide a correction of the fracturing fluid flow stream properties to summing stage 42. To provide the correction, the output of stage 32 can be multiplied by a pre-determined gain matrix 34 which can be processed through conversion inverse matrix 38. This stage this is the inverse of the fracturing model to convert the error correction input to a usable form (e.g. input viscosity, density, rate) for controlling the fracturing fluid flow stream properties. The inputs are derived by error correction vector [(L*−L)*k1, (W*−W)*k2, . . . ]*inverse(G). This decouples the cross couple of the states, so that L, w, h, and SC can be controlled independently. Depending on the hydrocarbon formation, this decoupling may or may not be possible, but this action at least minimizes the cross couple effects up to what is physically possible. and adjusted by cross coupled temporal delay stage 40. The delay is used to ensure all the inputs are driven at the same time context. For example, rate can be changed instantly, but viscosity is delayed by the pipe travel time due to the hold-up of the volume of the well. The output of stage 42 as corrected fluid property functions 43 can be used by stage 44 to generate drive vectors for the fracturing fluid making and supply system as surface components 330 in FIG. 3, as well as for down-hole tools 318, to be fed to control system 45. Control system 45 can then output signal 45A to control the surface and down-hole tools of the fracturing system, such as generally shown in site 300. The same information as signal 45B can then be used to update the current estimate of the state of the fracture and proppant placement therein. Signal 45B can be first conditioned using well delay stage 50 to adjust for the delay between when a fluid property such as density or viscosity is adjusted at the surface in the supply and making system and when such changes reach down-hole and begin to affect the mechanical fracturing process, if no down-hole tools are used to adjust those properties. If down-hole tools can be employed to adjust the properties, their use would effectively eliminate the need for the well delay stage 50. Additionally, changes in the fracturing fluid flow rate are essentially immediately effective down-hole and do not require adjustment by well delay 50. Fracturing model 48 can be used not only to create an initial fracture plan, but to estimate the current state of the fracture during fracturing in real-time. This estimate can use fracture well sensors 46, such as exemplified as down-hole sensors 326 and/or off-set sensors 340 and/or surface sensors 335 in FIG. 3. Model 48 can also use mechanical fracturing models known to a person skilled in the art of fracturing, as either two-dimensional or three dimensional, as described earlier, to estimate the propagation (e.g. the dimensions, geometry, orientation, and directional positioning) of fractures through a formation of given mechanical properties in relation the pumped volume, pumping rate, and rheologic properties of the fracturing fluid being used. Model 48 can also modify itself by comparing actual results of measurements of well sensors 46 to predicted results of the mechanical fracturing models to correct for any inaccuracies. Fracturing model 48 can generate an estimate of the current state of the fracture as signal 48B, where the signal 48B is used to determine the error in current state from planned state in summing stage 32 as described earlier. Model 48 can also supply the same information as signal 48A to allow fracturing plan 30 to be updated to a new fracture plan using an adaptive system within stage 30. Signal 45 as actuator saturation feedback can be used to inform the fracturing plan 30 that the system has reached an operational limit. In one embodiment, down hole fluid sensors can utilize the systems and methods of U.S. Pat. No. 6,978,831B2, to Phillip D. Nguyen, entitled “System and Method for Sensing Data in a Well During Fracturing”, granted Dec. 27, 2005, which is hereby incorporated by reference. In one embodiment, down hole viscosity can be adjusted using the methods of U.S. Pat. Nos. 6,719,055 and/or 6,959,773, both to Ali Mese and Mohamed Soliman, both entitled “Method for Drilling and Completing Boreholes with Electro-Rheological Fluids,” granted Apr. 13, 2004 and Nov. 1, 2005, respectively, which are hereby incorporated by reference. In one embodiment, down hole tools 318 can utilize the teaching, tools, and/or methods of U.S. Pat. No. 6,938,690, to Jim B. Surjaatmadja, entitled “Downhole Tool and Method for Fracturing a Subterranean Well Formation”, granted Sep. 6, 2005, which is hereby incorporated by reference. In one embodiment fracturing plan 30A is a time series of desired geometric parameters, locations, and dimensions of fracture 333 over the time the fracturing process is conducted, and the concentration and distribution of proppant within the fracture. In one embodiment, fracturing plan 30A is determined from a desired performance target for the fracturing operation where the target is a particular increase in production. Further to this embodiment, stage 30 uses the current fracture estimate 48A to predict a resulting fracture profile based on the progress and trends of the current fracture propagation and proppant placement. Further, a resulting hydrocarbon production performance increase of the finished and propped fracture is determined. The resulting performance increase is compared to the targeted performance increase. If the error is above a predetermined value, an adaptive model within stage 30 then adjusts the desired fracture profile over the remaining time for the process to better achieve the desired fracture performance increase. In one embodiment, well sensors 46 comprise tilt-meter measurements as known to one skilled in the art of seismic movement and displacement. In still another embodiment, the sensing measurements comprise micro-seismic event monitoring measurements as also known to such a skilled person. According to a disclosed class of innovative embodiments, there is provided a method for performing fracturing on a well, comprising the actions of (a) fracturing, in accordance with a fracturing model and a fracturing plan, while monitoring inputs used to estimate fracturing progress; (b) automatically modifying said fracturing model from time to time, as said monitoring action indicates that said fracturing model may be inaccurate; and (c) automatically modifying said fracturing plan, in dependence on said action (b). According to a disclosed class of innovative embodiments, there is provided a subterranean fracturing process system for a hydrocarbon well, comprising at least one pump for delivering a fracturing fluid flow stream into a hydrocarbon well, surface and/or down-hole actuators which jointly control the down-hole-values of one or more properties of said flow stream, and a control system which controls said actuators and said pump in relation to a subterranean fracturing plan using a fracturing model, to govern said down-hole values, wherein said control system further automatically modifies said fracturing model from time to time, when at least one monitoring action indicates that said fracturing model may be inaccurate; and wherein said control system automatically modifies said fracturing plan to optimize the results of the fracturing process. MODIFICATIONS AND VARIATIONS As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a range of applications, and accordingly the scope of patented subject matter is not limited by any of the specific exemplary teachings given. It is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims. The methods and systems of the present application can operate across a wide range of subterranean hydrocarbon formation fracturing and propping situations and conditions. One of ordinary skill in the art, with the benefit of this disclosure, will recognize the appropriate use of the methods and systems for a chosen application of a given or dynamic set of operating parameters. Optionally, the methods and systems of the present application can be configured or combined in various schemes. The combination or configuration depends partially on the required fracturing process control precision and accuracy and the operational envelope of the fracturing process. One of ordinary skill in the art of subterranean hydrocarbon formation fracturing, with the benefit of this disclosure, will recognize the appropriate combination or configuration for a chosen application. Optionally, flags such as a particular process variable out of range which may define the reliability of the data or provide variables to use for process control. One of ordinary skill in the art, with the benefit of this disclosure, will recognize the appropriate additional measurements that would be beneficial for a chosen application. Optionally, such measurements taken by the methods and systems of the present application may also be sent to the external system 344 of FIG. 3 for further processing or use. For example, if down-hole pressure exceeds a target by a certain amount, this fact could be used to re-tune process controllers, e.g. pump speed controllers. Or, for example, fluid viscosity having a large standard deviation beyond a preset level might be used for the same flagging determination to re-tune viscosity controllers. Optionally, rheologic property temperature compensation can be employed used to adjust for shifts in temperature using reference data sets relating temperature change to total fluid viscosity change, or curves fitted to such reference data. Optionally, because the viscosity changes of different fluid compositions or recipes can vary from application to application, or across different embodiments, different reference data sets or curves or hydraulic fracturing models fitted to such data sets may be employed, maintained, or stored in control system 342 or external system 344. One of ordinary skill in the art, with the benefit of this disclosure, will recognize the appropriate systems to employ for such viscosity compensation methods. Optionally, the methods of the present application can also be embodied in a set of instructions that can be used on a general purpose desktop or laptop computer or microprocessor system, or external system 344 in addition to being embodied in control system 342. The set of instructions can comprise input instructions that receives data or models from external system 344. Similarly, the input instructions can accept instructions from a user via one or more input devices, such as a keyboard, mouse, touchpad, or other input device. The instructions can cause the computer or microprocessor system to display information, such as the results of the methods of the present innovations, to a user, through a display monitor, printer, generated electronic file, or other such device. The instructions can also cause the computer or microprocessor system to transmit the results to a distant user via modem, cable, satellite, cell link, or other such means. For such digital communications, RS-422 or RS-485 can optionally be used to allow links control system 342 or external system 344 to multiple external units. Optionally, a 4-20 milliamp analog output signal can be used to allow external processing of the system measurements. Optionally, the methods of the present invention can also be embodied in a computer readable medium. None of the description in the present application should be read as implying that any particular element, step, or function is an essential element which must be included in the claim scope: THE SCOPE OF PATENTED SUBJECT MATTER IS DEFINED ONLY BY THE ALLOWED CLAIMS. Moreover, none of these claims are intended to invoke paragraph six of 35 USC section 112 unless the exact words “means for” are followed by a participle. The claims as filed are intended to be as comprehensive as possible, and NO subject matter is intentionally relinquished, dedicated, or abandoned.
|
E
|
E21
|
E21B
|
43
|
26
|
|||
11911682
|
US20080209842A1-20080904
|
Prefabricated Modular Tower
|
ACCEPTED
|
20080820
|
20080904
|
[]
|
E04H1212
|
["E04H1212"]
|
7770343
|
20071210
|
20100810
|
52
|
223500
|
96916.0
|
CANFIELD
|
ROBERT
|
[{"inventor_name_last": "Montaner Fraguet", "inventor_name_first": "Jesus", "inventor_city": "Huesca", "inventor_state": "", "inventor_country": "ES"}, {"inventor_name_last": "Mari Bernat", "inventor_name_first": "Antonio Ricardo", "inventor_city": "Huesca", "inventor_state": "", "inventor_country": "ES"}]
|
Prefabricated modular tower of the kind used as a support for wind generators and other applications, characterised in that it uses reduced-thickness prefabricated elements, reinforced with an internal structure of horizontal and vertical stiffeners, preferably made of reinforced concrete; said elements being tensioned both horizontally and vertically by means of flexible metal cables. The main advantages of the invention presented are that it enables fast construction of very high towers using a limited number of elements and that these elements are not heavy and are easy to transport, all of which leads to savings in manufacturing, transport and installation costs.
|
1. Prefabricated modular tower, of the kind used as a support for wind generators and other applications, characterised by being formed by a small number of tapered parts (1, 2, 3), each of which (1, 2, 3) is in turn formed by the lateral union of a small number of identical prefabricated modular elements (6,7,8), preferably made of reinforced concrete, in the right shape to form a tapered part of the tower when placed adjacently, their external wall (9) being smooth, characterised by the internal wall (10) having a plurality of prominent horizontal (11) and vertical (12) stiffeners that reinforce the reduced-thickness main wall (13) of the modular elements (6,7,8), the vertical sidewalls 14) having a groove all the way up, preferably of trapezoidal section, intended for the cement union joint (15). 2. Prefabricated modular tower, as described in claim 1, characterised by the fact that the horizontally arranged reinforcement stiffeners (11) in each of the prefabricated modular elements (6, 7, 8) have a central longitudinal tube (16) running all the way along them, that allows the passage of tensioning cables (17), preferably flexible and made of steel, which provide horizontal solidarity between the prefabricated modular elements (6, 7, 8) that make up each part of the tower (4), the prefabricated modules having appropriate access openings (18) to the horizontal central tubes (16). 3. Prefabricated modular tower, as described in claim 1, characterised by the fact that when the prefabricated modular elements (6, 7, 8) that make up each part of the tower (4) have been placed alongside one another and the horizontally arranged tensioning cables (17) have been tensed, the vertical union joints between each pair of modular elements (6, 7, 8) are closed, previously sealing the union from the outside and inside by means of a closure joint (19) and subsequently pouring a sealant, preferably of the liquid cement type (15), into the gap formed by the side grooves of the adjacent modular elements. 4. Prefabricated modular tower, as described in claim 1, characterised by the fact that the prefabricated modular elements (6,7,8) have a plurality of through-tubes (20) totally integrated inside the wall (13) and arranged vertically along it, through which the tensioning cables (21) that together provide vertical solidarization of the parts (1,2,3) comprising the tower, are passed, said vertical tensioning cables (21) being installed from the lower stiffener (22) of the prefabricated modular elements (6) that make up the lower part (1) of the tower (4), passing through the through-tubes (20) that are subsequently filled with mortar, solidarizing and integrating the cables inside the through-tubes (20) and thus inside the walls (13), remaining concealed both internally and externally and being preferably installed in groups of a single cable per tower part (4). 5. Prefabricated modular tower, as described in claim 1, characterised by the fact that the vertical components (1, 2, 3) of the tower are assembled on top of one another by means of a horizontal rotation equivalent to the angle distance that separates two vertical reinforcement stiffeners (12) from one another, so that the vertical jointing grooves (15) on each part between the prefabricated modular elements do not coincide vertically. 6. Prefabricated modular tower, as described in claim 1, characterised by the fact that in a preferred embodiment example the tower (4) is divided in three tapered parts (1, 2, 3), with an approximate height of 30 and 35 m each, which gives a total tower height of approximately 100 m, the lower part (1) comprising 5 identical prefabricated modular elements (6) placed alongside each other; the intermediate part (2) comprising a further 5 identical prefabricated modular elements (7), although of smaller diameter than the previous ones, also placed alongside each other and the upper part (3) being formed by only 3 prefabricated modular elements (8) which are the same as one another but different from the previous ones.
|
As its title indicates, the present descriptive report refers to a prefabricated modular tower of the kind used as a support for wind generators and other applications, characterised in that it uses reduced-thickness prefabricated elements, reinforced with an internal structure of horizontal and vertical stiffeners, preferably made of reinforced concrete; said elements being tensioned both horizontally and vertically by means of flexible metal cables. At present there is a wide range of kinds of wind-powered electricity generators, which are also known as wind generators. These generators comprise a turbine connected to blades that is supported on a tower. Most of the more commonly used generator support towers are metal and either have a lattice structure or a cylindrical or hollow tapered shape. These kinds of towers present a series of problems, among which we would mention the need for frequent maintenance with anti-rust treatments or paint, their short service life, which is usually less than 20 years due to exhaustion caused by material fatigue (because of the constant traction and compression cycles caused by the force of the wind they have to withstand) and the high manufacturing, transport and installation costs. An additional problem is the fact that they can only be used, from both the technical and economic viewpoint, for heights between 25 and 40 m. For heights over 50 m metal towers begin to be unfeasible, both because of their rigidity for withstanding stress and the high cost of the material involved, which greatly restricts the height of the wind generators. Current wind generator building trends are veering towards an increase in their power and much higher positioning of the turbine and the blades. Turbines are also being equipped with much larger blades in order to avoid the screen effect of mountains and in an endeavour to make use of the higher air layers where the flow is more constant and power production therefore much greater. This means that tower-building alternatives must be found to cater for heights well above 50 m and in fact closer to 90 or 100 m. The rigidity required means that it is no longer feasible to build these towers with metal structures and for this reason attempts have been made to build them with reinforced concrete, which is much more rigid and resistant and also far more economical. Some towers are built on site using casing in the form of latticework or a similar structure, just as buildings and skyscrapers are, but this has the disadvantage of being a slow, costly process, particularly due to the labour costs involved. An example of this building technique can be found in patent JP 200100658 “Very tall tower” or in patent DE 19936603 “Structural engineering method for hollow mast or concrete structure as a tower, for example, for a wind farm, comprising a guide structure for work used during the construction installed in the inside space”. Attempts have been made to find other solutions. For example patent WO 2004007955 “Method for the production of a cement segment for a wind farm tower” presents a construction system using full stackable tapered segments made in a prefabricated concrete factory and transported to the site, which has the problem that the segments have to be quite short if they are to be transported using conventional road transport methods, with all the relevant legal and practical limitations, which means that they have to use a very large number of stacked segments to make the tower, which generates high transport and labour costs, which are coupled with the cost of the constant use of cranes for installation and assembly. An added disadvantage of this method is the fact that, to build a tapered tower, each segment has different measurements, which means that there have to be as many moulds as there are segments in the tower, which increases the complexity of the production process. Furthermore, to achieve the necessary rigidity and solidity, the segment walls must be considerably thick, which increases their cost and the weight to be transported. In an endeavour to reduce the size of the parts to be transported attempts have been made to divide each tapered mast segment into separate pieces as described in Utility Model 200402304 “Improved modular tower structure for wind turbines and other applications”, and in Patent W003/069099 “Wind Turbine”, but both have the disadvantage of using very thick solid walls that are smooth both inside and outside in order to achieve structural rigidity and resistance, which puts up the price of the items considerably and also means that a large number of pieces are required to build the tower, with the consequent high cost both in terms of transport and assembly, apart from the high manufacturing cost generated by the large number of manufacturing moulds needed and the high structural weight involved. In addition, towers are known, such as that described in Utility Model 200402504 “Perfected structure of a modular tower for wind turbines and other applications”, which have in common with the others the fact that they use separate pieces to form the segments in which, to achieve the structural stiffness and resistance, solid walls of a considerable thickness are used, these being smooth on the inside and outside. Given the notable increase in weight of the pieces this produces the same problem as when a large number of pieces are needed to form the tower, with a high economic cost of both transport and assembly. Moreover, to reinforce the structure of the tower, this embodiment employs an external pre-tensioning system consisting of vertical tensioning cables that have the problem of having to be attached to the foundations of the tower, which must therefore be equipped with appropriate anchorages, also presenting the problem that the cables are only attached to the walls at the through-holes of the flanges on said walls, meaning that there is only partial contact with walls and that the reinforcement is therefore fairly poor. Moreover, most of the cables are left outside the wall, on the inside of the tower, and exposed to the air, which causes a negative visual impact as well as the added problem of deterioration that is caused by the stressing effort of the cables together with atmospheric wear and corrosion that enormously limits their useful life. The prefabricated modular tower that is the subject of the present invention was designed to solve the problems involved in the current issue of building very tall support towers for wind generators and other applications. It uses reduced-thickness prefabricated elements that are reinforced with an internal structure of horizontal and vertical stiffeners made preferably of reinforced concrete; the elements are tensioned both horizontally and vertically by means of flexible metal cables. The tower is divided into a small number of tapered parts, each of which is, in turn, formed by the lateral coupling of a reduced number of identical prefabricated modular elements made preferably of reinforced concrete. In a preferred embodiment example, the tower is divided into three tapered parts with a height of approximately 30 to 35 m each, which gives a total tower height of approximately 100 m. In this preferred embodiment example, the lower part is formed of 5 identical prefabricated modular elements placed alongside one another: the intermediate part is formed by a further 5 identical prefabricated modular elements, although obviously of smaller diameter than those referred to above, which are also placed alongside one another; the upper part is formed by only 3 prefabricated modular elements, which are the same as one another but different from the previous ones. This preferred embodiment example shows us how a 100 m tall tower is made using only 13 prefabricated modular elements of only 3 different kinds and therefore requiring only 3 manufacturing moulds. Each of the prefabricated modular elements is the right shape to form a tapered part of the tower when placed adjacently. Their external wall is smooth while the internal wall has numerous prominent horizontal and vertical reinforcement stiffeners that allow the main wall of the modular elements to be of limited thickness, while still providing high rigidity and resistance and thus leading to a considerable reduction in the weight of the prefabricated modular element. The vertical sidewalls, of a reduced width, have a groove all the way up, preferably of trapezoidal section, intended for the cement union joint. The horizontally-arranged reinforcement stiffeners each have a central longitudinal tube running all the way along them, through which the tensioning cables, preferably flexible and made of steel, are passed. They provide horizontal solidarity between the prefabricated modular elements that make up each part of the tower, thus helping to increase overall rigidity and stability. This solidarization will be achieved preferably by dividing each horizontal run into two cable sections, instead of having only one, so as to tense the cables more easily by means of the relevant jacks or similar tools. For this purpose, the prefabricated modules will have appropriate openings providing access to the horizontal central tubes. When the prefabricated modular elements that make up each part of the tower have been placed alongside one another and the horizontally arranged tensioning cables have been tensed, the vertical union joints between each pair of modular elements will be closed, first sealing the joint from the outside and inside by means of a closure seal and subsequently pouring a sealant, preferably of the liquid cement type, into the gap formed by the lateral grooves of the adjacent modular elements, which, when it sets will contribute to the solidity of the unit. The prefabricated modular elements also have a plurality of through-tubes arranged vertically on the wall and completely integrated in it, for the purpose of passing through them the preferably flexible, tensioning steel cables that provide vertical solidarization of the parts comprising the tower. These vertical tensioning cables will be installed from the lower stiffener of the prefabricated modular elements that form the lower part of the tower, passing through the through-tubes which are subsequently filled with mortar that secures and integrate the cables inside the through-tubes and hence inside the walls, being concealed both internally and externally and completely solidarized with the towers. Said cables are installed in groups of one cable per tower part (three cables in the preferred embodiment example), in such a way that the first cables in each group will be tensioned above the joint between the first part and the second part; the second cables of each group will be tensioned above the joint between the second part and the third part and so on. In this way, they help to tension the tower as a whole, all the way up. The through-tubes are subsequently filled with mortar and another similar element. The vertical cables are, in this way, totally integrated in the tower walls, contributing to its rigidity but remaining concealed from sight, both inside and outside the tower. As well as using the vertical tensioning cables for this purpose, the joining of the different parts that make up the tower vertically will be carried out using common jointing methods in prefabricated concrete products, such as bridle joints or a receptacle filled with liquid cement, protected by a gutter to keep rainwater out. A feature of the invention is that the vertical components of the tower will be assembled on top of one another with a horizontal rotation equivalent to the angle distance that separates two vertical reinforcement stiffeners from one another, so that the vertical jointing grooves on each part between the prefabricated modular elements do not coincide vertically, without altering the perfect support between the vertical stiffeners, thus improving its insulation against water. For each prefabricated modular element there will preferably be two complete vertical stiffeners and two semi-stiffeners at the ends, which, when joined together, form the equivalent of one stiffener, in order to make this rotation possible. The joining of the base of the first part of the tower with the foundation is carried out by means of conventional foundation-building and anchorage techniques used in construction, such as screwing down with rigid bars or similar, appropriately dimensioned in line with the size of the tower. The last part of the tower can be linked to another prefabricated concrete or metal section of the tower or it can directly support the wind generator enclosure and the blade support structure. The prefabricated modular tower presented has numerous advantages over currently available systems, the most important of which is to enable very tall towers to be constructed quickly using a reduced number of elements. In the preferred embodiment example one can see how a tower some 100 m tall is built using only 13 prefabricated modular elements, of which there only need to be 3 different kinds, thus requiring only 3 different manufacturing moulds. Another considerable advantage is that, because the prefabricated modular elements are equipped with reinforcement stiffeners, they weigh considerably less, which facilitates transport and therefore provides savings in manufacture, transport and installation costs. It is important to underline the unquestionable advantage of the fact that, in the preferred embodiment example the dimensions of each of the prefabricated modular elements are calculated according to their approximate length, which is between 30 and 35 m, while the maximum width of each element is 4.5 m to make normal road transport possible. Given that the remaining measurement is usually about 70 cm, temporary reinforcement in the form of metal latticework can be put in place to support parts during transport or during assembly on the site. Another advantage of the present invention is that the entire tower is perfectly tensed by cables both horizontally and vertically. Attention must be drawn to the important advantage of the vertical cables being totally integrated in the tower walls, passed through the through-tubes inserted in the walls and subsequently filled with mortar, contributing to their rigidity, but remaining concealed both on the inside and outside of the tower, which also greatly improves the duration of the cable since contact with the exterior and atmospheric degradation is avoided. For a better understanding of the subject of the present invention, a practical preferred embodiment of a prefabricated modular tower such as the one described above has been represented in the attached drawing. In this drawing FIG. -1- shows an elevation and plan view of the tower in which the three parts comprising it can be seen. FIG. -2- shows a partial view of one of the parts of the tower that has not been fully closed, showing the internal stiffeners and an enlarged detailed view of them showing the internal tube of the horizontal stiffeners. FIG. -3- shows a cross section of the base the first part of the tower, showing the five prefabricated modular elements of which it is comprised, with an enlarged detail of the closure of the lateral union between the elements. FIG. -4- shows a cross section of the first part of the tower at the level of one of the horizontal reinforcement stiffeners, showing the five prefabricated modular elements of which it is comprised, with an enlarged detail of the closure of the lateral union between the elements and a further one of the accesses for tensioning the horizontal cables. FIG. -5- shows a cross section of the first part of the tower at intermediate height, showing the five prefabricated modular elements of which it is comprised. FIG. -6- shows a cross section of the base of the second part of the tower, showing the five prefabricated modular elements of which it is comprised. FIG. -7- shows a cross section of the second part of the tower at the height of one of the horizontal reinforcement stiffeners, showing the five prefabricated modular elements of which it is comprised. FIG. -8- shows a cross section of the second part of the tower at an intermediate height, showing the five prefabricated modular elements of which it is comprised. FIG. -9- shows a cross section of the terminal part of the second part of the tower, showing the five prefabricated modular elements of which it is comprised. FIG. -10- shows a cross section of the third part of the tower at the height of one of the reinforcement horizontal stiffeners, showing the three prefabricated modular elements of which it is comprised. FIG. -11- shows a cross section of the third part of the tower at intermediate height, showing the three prefabricated modular elements of which it is comprised. FIG. -12- shows a cross section of the end part of the third part of the tower, showing the three prefabricated modular elements of which it is comprised. FIG. -13- shows the cross sections of the sidewalls of the three parts of the towers. FIG. -14- shows a side cross section illustrating the course of a set of three vertical tensioning cables. As can be seen in the attached drawing, the prefabricated modular tower (4) that is the subject of the present invention, basically comprises a small number of tapered parts (1,2,3), each of which (1,2,3) is in turn formed by the lateral union of a small number of identical prefabricated modular elements (6,7,8) preferably made of reinforced concrete. In a preferred embodiment example, the tower (4) is divided in three tapered parts (1,2,3), with an approximate height of 30 to 35 m in each part, which gives a total tower height of approximately 100 m. In this preferred embodiment example the lower part (1) is formed by 5 identical prefabricated modular elements (6) placed alongside each other; the intermediate part (2) is formed by a further 5 identical prefabricated modular elements (7), although of smaller diameter than the previous ones, which are also placed alongside one another and the upper part (3) is formed by only 3 prefabricated modular elements (8), which are the same as one another but different from the previous ones. As we have seen above, each of the prefabricated modular elements (6, 7, 8) is the right shape to form a tapered part of the tower when placed adjacently. Their external wall (9) is smooth while the internal wall (10) has numerous prominent horizontal (11) and vertical (12) reinforcement stiffeners that allow the main wall (13) of the modular elements (6,7,8) to be of limited thickness. The vertical sidewalls, of reduced width, have a groove (14) all the way up, preferably of trapezoidal section, intended for the cement union joint (15). The horizontally arranged reinforcement stiffeners (11) each have a central longitudinal tube (16) running all the way along them, through which the tensioning cables (17), preferably flexible and made of steel, are passed. They provide horizontal solidarity between the prefabricated modular elements (6, 7, 8) that make up each part of the tower (4), the prefabricated modules having appropriate access openings (18) to the horizontal central tubes (16). When the prefabricated modular elements (6, 7, 8) that make up each part of the tower (4) have been placed alongside one another and the horizontally arranged tensioning cables (17) have been tensed, the vertical union joints between each pair of modular elements (6, 7, 8) will be closed, previously sealing the joint from the outside and inside by means of a closure seal (19) and subsequently pouring a sealant, preferably of the liquid cement type (15) in the gap made by the lateral grooves of the adjacent modular elements. The prefabricated modular elements (6, 7, 8) also have a large number of through-tubes (20) arranged vertically along the wall (13), through which the tensioning cables (21) that provide vertical solidarization of the parts (1, 2, 3) comprising the tower, are passed. These vertical tensioning cables (21) will be installed from the lower stiffener (22) of the prefabricated modular elements (6), without having to prolong them to the foundations, that form the lower part (1) of the tower (4), passing through the through-tubes (20) that are subsequently filled with mortar, solidarizing and integrating the cables inside the through-tubes (20) and hence inside the walls (13), remaining concealed both internally and externally and being preferably installed in groups of a single cable per tower part (4) (three cables in this preferred embodiment example). In this way the vertical tensioning cables (21) are totally attached to the tower (4) all the way up. A feature of the invention is that vertical components (1, 2, 3) of the tower are assembled on top of one another by means of a horizontal rotation equivalent to the angle distance that separates two vertical reinforcement stiffeners (12) from one another, so that the vertical jointing grooves (15) on each part between the prefabricated modular elements do not coincide vertically. We voluntarily omit giving a detailed description of the other particularities of the system presented or its components as we consider that they are not subject to any claim. Having described the nature and a preferred embodiment of the present invention in sufficient detail, it only remains for us to say that the description is not restrictive and some variations may be made, both with regard to materials and shapes or sizes, provided such variations do not alter the essential characteristics that are claimed below.
|
E
|
E04
|
E04H
|
12
|
12
|
|||||
11943746
|
US20080074514A1-20080327
|
IMAGE DATA CORRECTION PROCESSING BASED ON SENSITIVITY
|
ACCEPTED
|
20080312
|
20080327
|
[]
|
H04N5217
|
["H04N5217"]
|
7978238
|
20071121
|
20110712
|
348
|
231600
|
97956.0
|
TREHAN
|
AKSHAY
|
[{"inventor_name_last": "HARADA", "inventor_name_first": "Osamu", "inventor_city": "Kanagawa", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Sakamoto", "inventor_name_first": "Hiromichi", "inventor_city": "Tokyo", "inventor_state": "", "inventor_country": "JP"}]
|
A signal processing device includes a memory which stores correction data in advance. The signal processing device modifies the correction data stored in the memory on the basis of an image sensing signal obtained by causing an image sensing unit to perform image sensing operation in a non-exposure state. The signal processing device corrects by using the modified correction data an image sensing signal obtained by causing the image sensing unit to perform image sensing operation in an exposure state.
|
1. An image sensing apparatus comprising: an image sensing device; and a correction unit that corrects noise in image data obtained by said image sensing device, the noise being due to at least dark current generated in said image sensing device, wherein said correction unit selects, at least based on setting state of said image sensing apparatus and environmental condition, either one of: correcting the image data using first correction data pre-stored in a storage medium; and obtaining second correction data, that is different from the first correction data, from the output of said image sensing device with being shielded from light and correcting the image data using the second correction data. 2. The image sensing apparatus according to claim 1 further comprising an operation member that is used for starting auto focus control and auto exposure control, wherein the first correction data is pre-stored in the storage medium before said operation member is operated, and the second correction data is obtained after said operation member is operated. 3. The image sensing apparatus according to claim 1, wherein said correction unit obtains the second correction data before acquiring the image data if a sequential image sensing is set as the setting state, and obtains the second correction data after acquiring the image data if a single-shot image sensing is set as the setting state. 4. The image sensing apparatus according to claim 1, wherein said correction unit corrects the image data using the second correction data if a sensitivity set in said image sensing apparatus is higher than a reference sensitivity. 5. The image sensing apparatus according to claim 1, wherein said correction unit corrects the image data using the second correction data if an exposure period of time for obtaining the image data is set longer than a predetermined period of time. 6. The image sensing apparatus according to claim 1, wherein said correction unit corrects the image data using the second correction data if temperature at the time of obtaining the image data is higher than a predetermined temperature.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Image processing apparatuses such as an electronic camera which uses a memory card having a solid-state memory element as a recording medium, and records and plays back still and moving images sensed by a solid-state image sensing device (to be described as an image sensing device hereinafter) such as a CCD or CMOS have commercially been available. This image processing apparatus such as an electronic camera allows the photographer to select a single-shot/sequential image sensing mode from the operation unit. The photographer can switch image sensing between single-shot image sensing for sensing an image for each frame every time he/she presses the shutter button and sequential image sensing for sequentially sensing images while he/she keeps pressing the shutter button. To sense an image by using the image sensing device such as a CCD or CMOS, the image processing apparatus can execute dark noise correction processing by calculation processing using dark image data read out after charge accumulation similar to actual image sensing while the image sensing device is not exposed, and image data of actual image sensing read out after charge accumulation while the image sensing device is exposed. A high-quality image can be attained by correcting the sensed image data for image quality degradation caused by dark current noise generated by the image sensing device, a defective pixel due to a slight scratch unique to the image sensing device, or the like. However, in order to cause the image processing apparatus to perform dark noise correction processing, a dark image must be sensed. This increases the release time lag, missing a good opportunity of capturing an image. To solve this problem, there is known an image processing apparatus which uses correction data stored in advance to cancel the horizontal shading (luminance level nonuniformity) of the image sensing device or a noise component (offset from a proper dark level) such as a dark current, and can sense a high-quality image while suppressing the release time lag small. The correction data stored in advance is an offset amount for canceling the horizontal shading of the image sensing device, or the difference between a proper dark level and image data obtained by performing dark image sensing but not performing correction using correction data in assembling an image processing apparatus. The dark level serves as a criterion for the luminance component and color components of image data in image processing. The image quality can therefore be improved by correcting the dark level of image data obtained by exposing the image sensing device. The prior art suffers the following problems. Some image sensing devices nonlinearly change the dark current noise state depending on the temperature characteristic of an output circuit. In an image processing apparatus having such an image sensing system, a noise component which should be canceled remains in sensed image data even by using a correction value stored in advance, degrading the image quality. In this case, correction by calculation using a temperature coefficient complicates the calculation. Calculation processing takes a long time in the presence of many pixels, increasing the release time lag. A correction value may be stored in advance for each temperature region, which requires a larger memory capacity and makes the apparatus bulky. In addition to dark noise correction processing, the image processing apparatus can execute shading correction processing by calculation processing using shading correction data stored in advance in a storage medium, and sensed image data read out after charge accumulation while the image sensing device is exposed. Noise generated in an image sensing circuit system, i.e., the voltage nonuniformity caused by the resistance component of the power line in a sensor, and shading by element variations or the like can be reduced, sensing a high-quality image. However, the prior art poses the following problems. In a conventional image processing apparatus such as an electronic camera, shading correction data is stored in a storage medium in advance. In image sensing, the shading correction data is read out from the storage medium, and calculation processing is performed using the shading correction data and sensed image data, achieving shading correction. If the change of the shading amount depending on image sensing conditions is not considered, appropriate shading correction cannot be done, and the image quality may degrade. If the change of the shading amount depending on image sensing conditions is considered, the number of shading correction data corresponding to respective image sensing conditions must be stored in the storage medium, which requires a large-capacity storage medium.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention has been made in consideration of the above situation, and has as its object to properly correct the noise and shading of a sensed image. According to the present invention, the foregoing object is attained by providing an apparatus comprising: (A) a memory adapted to store correction data; (B) a signal processing device adapted to modify the correction data stored in the memory by using an image sensing signal obtained by causing an image sensing unit to perform image sensing operation in a non-exposure state, and adapted to correct by using the modified correction data an image sensing signal obtained by causing the image sensing unit to perform image sensing operation in an exposure state. According to the present invention, the foregoing object is also attained by providing an apparatus comprising: (A) a memory adapted to store shading correction data; (B) a signal processing device adapted to modify the shading correction data stored in the memory in accordance with an image sensing condition and correct an image sensing signal by using the modified shading correction data. According to the present invention, the foregoing object is also attained by providing an image processing method comprising modifying correction data stored in a memory by using an image sensing signal obtained by causing an image sensing unit to perform image sensing operation in a non-exposure state, and correcting by using the modified correction data an image sensing signal obtained by causing the image sensing unit to perform image sensing operation in an exposure state. According to the present invention, the foregoing object is also attained by providing an image processing method comprising modifying shading correction data stored in a memory in accordance with an image sensing condition, and correcting an image sensing signal by using the modified shading correction data. Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
|
This application is a continuation of prior application Ser. No. 10/370,972, filed Feb. 20, 2003, to which priority under 35 U.S.C. §120 is claimed. This application also claims a benefit of priority based on Japanese Patent Applications No. 2002-042933, filed on Feb. 20, 2002, and No. 2002-064086, filed on Mar. 8, 2002, both of which are hereby incorporated by reference herein in their entirety as if fully set forth herein. FIELD OF THE INVENTION The present invention relates to correction processing and control such as shading correction performed on image data obtained from an image sensing device. BACKGROUND OF THE INVENTION Image processing apparatuses such as an electronic camera which uses a memory card having a solid-state memory element as a recording medium, and records and plays back still and moving images sensed by a solid-state image sensing device (to be described as an image sensing device hereinafter) such as a CCD or CMOS have commercially been available. This image processing apparatus such as an electronic camera allows the photographer to select a single-shot/sequential image sensing mode from the operation unit. The photographer can switch image sensing between single-shot image sensing for sensing an image for each frame every time he/she presses the shutter button and sequential image sensing for sequentially sensing images while he/she keeps pressing the shutter button. To sense an image by using the image sensing device such as a CCD or CMOS, the image processing apparatus can execute dark noise correction processing by calculation processing using dark image data read out after charge accumulation similar to actual image sensing while the image sensing device is not exposed, and image data of actual image sensing read out after charge accumulation while the image sensing device is exposed. A high-quality image can be attained by correcting the sensed image data for image quality degradation caused by dark current noise generated by the image sensing device, a defective pixel due to a slight scratch unique to the image sensing device, or the like. However, in order to cause the image processing apparatus to perform dark noise correction processing, a dark image must be sensed. This increases the release time lag, missing a good opportunity of capturing an image. To solve this problem, there is known an image processing apparatus which uses correction data stored in advance to cancel the horizontal shading (luminance level nonuniformity) of the image sensing device or a noise component (offset from a proper dark level) such as a dark current, and can sense a high-quality image while suppressing the release time lag small. The correction data stored in advance is an offset amount for canceling the horizontal shading of the image sensing device, or the difference between a proper dark level and image data obtained by performing dark image sensing but not performing correction using correction data in assembling an image processing apparatus. The dark level serves as a criterion for the luminance component and color components of image data in image processing. The image quality can therefore be improved by correcting the dark level of image data obtained by exposing the image sensing device. The prior art suffers the following problems. Some image sensing devices nonlinearly change the dark current noise state depending on the temperature characteristic of an output circuit. In an image processing apparatus having such an image sensing system, a noise component which should be canceled remains in sensed image data even by using a correction value stored in advance, degrading the image quality. In this case, correction by calculation using a temperature coefficient complicates the calculation. Calculation processing takes a long time in the presence of many pixels, increasing the release time lag. A correction value may be stored in advance for each temperature region, which requires a larger memory capacity and makes the apparatus bulky. In addition to dark noise correction processing, the image processing apparatus can execute shading correction processing by calculation processing using shading correction data stored in advance in a storage medium, and sensed image data read out after charge accumulation while the image sensing device is exposed. Noise generated in an image sensing circuit system, i.e., the voltage nonuniformity caused by the resistance component of the power line in a sensor, and shading by element variations or the like can be reduced, sensing a high-quality image. However, the prior art poses the following problems. In a conventional image processing apparatus such as an electronic camera, shading correction data is stored in a storage medium in advance. In image sensing, the shading correction data is read out from the storage medium, and calculation processing is performed using the shading correction data and sensed image data, achieving shading correction. If the change of the shading amount depending on image sensing conditions is not considered, appropriate shading correction cannot be done, and the image quality may degrade. If the change of the shading amount depending on image sensing conditions is considered, the number of shading correction data corresponding to respective image sensing conditions must be stored in the storage medium, which requires a large-capacity storage medium. SUMMARY OF THE INVENTION The present invention has been made in consideration of the above situation, and has as its object to properly correct the noise and shading of a sensed image. According to the present invention, the foregoing object is attained by providing an apparatus comprising: (A) a memory adapted to store correction data; (B) a signal processing device adapted to modify the correction data stored in the memory by using an image sensing signal obtained by causing an image sensing unit to perform image sensing operation in a non-exposure state, and adapted to correct by using the modified correction data an image sensing signal obtained by causing the image sensing unit to perform image sensing operation in an exposure state. According to the present invention, the foregoing object is also attained by providing an apparatus comprising: (A) a memory adapted to store shading correction data; (B) a signal processing device adapted to modify the shading correction data stored in the memory in accordance with an image sensing condition and correct an image sensing signal by using the modified shading correction data. According to the present invention, the foregoing object is also attained by providing an image processing method comprising modifying correction data stored in a memory by using an image sensing signal obtained by causing an image sensing unit to perform image sensing operation in a non-exposure state, and correcting by using the modified correction data an image sensing signal obtained by causing the image sensing unit to perform image sensing operation in an exposure state. According to the present invention, the foregoing object is also attained by providing an image processing method comprising modifying shading correction data stored in a memory in accordance with an image sensing condition, and correcting an image sensing signal by using the modified shading correction data. Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. FIG. 1 is a block diagram showing the configuration of an image processing apparatus according to embodiments of the present invention; FIG. 2 is a flow chart showing the main routine in the image processing apparatus according to the embodiments; FIG. 3 is a flow chart showing the main routine in the image processing apparatus according to a first embodiment of the present invention; FIG. 4 is a flow chart showing a distance measurement/photometry processing routine in the image processing apparatus according to the embodiments; FIG. 5 is a flow chart showing an image sensing processing routine in the image processing apparatus according to the embodiments; FIG. 6 is a flow chart showing a correction data change processing routine in the image processing apparatus according to the first embodiment of the present invention; FIG. 7 is a block diagram showing the arrangement of the main part of an image processing apparatus according to a second embodiment of the present invention; FIG. 8 is a flow chart showing the main routine according to the second embodiment of the present invention; FIG. 9 is a flow chart showing the main routine according to the second embodiment of the present invention; FIG. 10 is a flow chart showing a dark capturing processing routine according to the second embodiment of the present invention; FIG. 11 is a flow chart showing a shading correction data mapping routine according to the second embodiment of the present invention; FIGS. 12A to 12C are graphs for explaining shading correction data calculation processing according to the second embodiment of the present invention, in which FIG. 12A shows shading correction data at a reference ISO sensitivity, FIG. 12B shows gain-converted shading correction data, and FIG. 12C shows offset-converted shading correction data; and FIG. 13 is an explanatory view showing an image sensing operation flow according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail in accordance with the accompanying drawings. First Embodiment FIG. 1 is a block diagram showing the configuration of an image processing apparatus according to the first embodiment of the present invention. The image processing apparatus comprises an image processing apparatus (main body) 100, recording media 200 and 210 detachably mounted in the image processing apparatus main body 100, and a lens unit 300 detachably mounted on the image processing apparatus main body 100. In the image processing apparatus 100, a shutter 12 controls the exposure amount to an image sensing device 14. The image sensing device 14 converts an optical image of an object into an electrical signal. The image processing apparatus 100 of the first embodiment has the first image sensing mode in which charges are accumulated without exposing the image sensing device 14, and the second image sensing mode in which charges are accumulated while the image sensing device 14 is exposed. In a single-lens reflex camera, light incident on a lens 310 of the lens unit 300 is guided via a stop 312, a lens mount 306, and a lens mount 106, a mirror 130, and the shutter 12 of the image processing apparatus 100, forming an optical image on the image sensing device 14. An A/D converter 16 converts an analog signal output from the image sensing device 14 into a digital signal. A timing generator 18 supplies a clock signal and control signal respectively to the image sensing device 14, the A/D converter 16, and a D/A converter 26 under the control of a memory controller 22 and a system controller 50. An image processor 20 performs predetermined pixel interpolation processing and color conversion processing on data from the A/D converter 16 or data from the memory controller 22. If necessary, the image processor 20 performs predetermined calculation processing using sensed image data, and the system controller 50 performs TTL (Through-The-Lens) AF (Auto Focus) processing, AE (Auto Exposure) processing, and EF (pre-flash) processing with respect to a shutter controller 40 and a distance measurement unit 42 on the basis of the result of calculations. Further, the image processor 20 performs predetermined calculation processing using sensed image data, and performs TTL AWB (Auto White Balance) processing on the basis of the result of calculations. In the first embodiment, the image processing apparatus 100 comprises the dedicated distance measurement unit 42 and a dedicated photometry unit 46. It is also possible to perform AF processing, AE processing, and EF processing by using the distance measurement unit 42 and photometry unit 46, and not to perform AF processing, AE processing, and EF processing by using the image processor 20. It is also possible to perform AF processing, AE processing, and EF processing by using the distance measurement unit 42 and photometry unit 46, and further to perform AF processing, AE processing, and EF processing by using the image processor 20. The memory controller 22 controls the A/D converter 16, the timing generator 18, the image processor 20, an image display memory 24, the D/A converter 26, a memory 30, and a compression/expansion circuit 32. Data from the A/D converter 16 is written into the image display memory 24 or memory 30 via the image processor 20 and memory controller 22, or directly via the memory controller 22. The image display memory 24 stores display image data. The D/A converter 26 converts a digital signal output from the memory controller 22 into an analog signal. An image display unit 28 comprises a TFT LCD or the like. Display image data written in the image display memory 24 is displayed on the image display unit 28 via the D/A converter 26. An electronic finder function can be realized by sequentially displaying sensed image data on the image display unit 28. Further, the image display unit 28 arbitrarily turns ON/OFF its display in accordance with an instruction from the system controller 50. If the display is turned OFF, the electric consumption of the image processing apparatus 100 can be greatly reduced. The memory 30, used for storing sensed still images and moving images, has a sufficient storage capacity for storing a predetermined number of still images and a moving image for a predetermined period. In sequential image sensing to sequentially sense a plurality of still images or in panoramic image sensing, a large number of images can be written into the memory 30 at a high speed. The memory 30 may be used as a work area for the system controller 50. The compression/expansion circuit 32 compresses or expands image data by adaptive discrete cosine transformation (ADCT) or the like. The compression/expansion circuit 32 reads out an image stored in the memory 30, performs compression or expansion processing on the read image, and writes the processed data into the memory 30. Based on photometry information from the photometry unit 46, the shutter controller 40 controls the shutter 12 in association with a stop controller 340 which controls the stop 312 of the lens unit 300. The distance measurement unit 42 performs AF processing. Light incident on the lens 310 of the lens unit 300 is guided to enter the distance measurement unit 42 via the stop 312, the lens mount 306, and the lens mount 106, mirror 130, and distance measurement sub-mirror (not shown) of the image processing apparatus 100 in a single-lens reflex camera, thereby measuring the focus state of an image formed as an optical image. A thermometer 44 can detect the temperature of the image sensing environment. When the thermometer 44 is incorporated in the sensor (image sensing device 14), the dark current of the sensor can be more accurately expected. The photometry unit 46 performs AE (Auto Exposure) processing. Light incident on the lens 310 of the lens unit 300 is guided to enter the photometry unit 46 via the stop 312, the lens mount 306, and the lens mount 106, the mirror 130, a mirror 132, and a photometry lens (not shown) of the image processing apparatus 100 in a single-lens reflex camera, thereby measuring the exposure state of an image formed as an optical image. The photometry unit 46 has an EF processing function in association with a flash 48. The flash 48 has an AF auxiliary light projection function and a flash adjusting function. The system controller 50 can also perform exposure control and AF control by the video TTL method of controlling the shutter controller 40, the stop controller 340, and a distance measurement controller 342, on the basis of the result of calculations by the image processor 20 for image data sensed by the image sensing device 14. AF control may be performed using both the result of measurements by the distance measurement unit 42 and the result of calculations by the image processor 20 for image data sensed by the image sensing device 14. Exposure control may be done using both the result of measurements by the photometry unit 46 and the result of calculations by the image processor 20 for image data sensed by the image sensing device 14. The system controller 50 controls the overall image processing apparatus 100, and executes the processing of each flow chart to be described later on the basis of an internal program stored in, e.g., a memory 52 in the image processing apparatus 100 or an external program supplied to the image processing apparatus 100. The memory 52 stores constants, variables, programs, and the like for operating the system controller 50. A notification unit 54 comprises a liquid crystal display device and loudspeaker which display and output operating statuses, messages, and the like by using characters, images, sound, and the like in accordance with execution of a program by the system controller 50. One or a plurality of notification units 54 are arranged at easy-to-see positions near the operation unit of the image processing apparatus 100, and formed from a combination of LCDs, LEDs, sound generating devices, and the like. Some functions of the notification unit 54 are provided within an optical finder 104. The display contents of the notification unit 54, displayed on the LCD or the like, include indication of single-shot/sequential image sensing, a self timer, a compression ratio, an ISO (International Organization for Standardization) sensitivity, the number of recording pixels, the number of recorded images, the number of recordable images, a shutter speed, an f-number, exposure compensation, flash illumination, pink-eye effect mitigation, macro image sensing, a buzzer-set state, a remaining timer battery level, a remaining battery level, an error state, information of plural digit numbers, the attached/detached status of the recording media 200 and 210, the attached/detached status of the lens unit 300, the operation of a communication I/F, date and time, and a connection state to an external computer. Further, the display contents of the notification unit 54, displayed within the optical finder 104, include a focus state, an image sensing “ready” state, a camera shake warning, a flash charge state, a flash charge completion state, a shutter speed, an f-number, exposure compensation, and write operation into a recording medium. The display contents of the notification unit 54, displayed on the LED or the like, include a focus state, an image sensing “ready” state, a camera shake warning, a flash charge state, a flash charge completion state, write operation into a recording medium, a macro image sensing setting notification, and a secondary battery charge state. The display contents of the notification unit 54, displayed on the lamp or the like, include a self-timer notification lamp. The self-timer notification lamp may also be used for AF auxiliary light. A nonvolatile memory 56 is an electrically erasable and recordable memory such as an EEPROM. The nonvolatile memory 56 stores various parameters, set values such as the ISO sensitivity, set modes, and one-dimensional correction data used for horizontal dark shading correction. One-dimensional correction data is created and written in adjustment during the manufacturing process of the image processing apparatus. Operation means 60, 62, 64, 66, 68, 69, and 70 are used to input various operation instructions to the system controller 50, and comprise one or a plurality of combinations of switches, dials, touch panels, a device for pointing by line-of-sight detection, a voice recognition device, and the like. These operation means will be described in detail. The mode dial switch 60 allows switching and setting function image sensing modes such as an automatic image sensing mode, a programmed image sensing mode, a shutter speed priority image sensing mode, a stop priority image sensing mode, a manual image sensing mode, a focal depth priority (depth) image sending mode, a portrait image sensing mode, landscape image sensing mode, a close-up image sensing mode, a sports image sensing mode, a night view image sensing mode, and a panoramic image sensing mode. The shutter switch SW1 62 is turned ON by half stroke of the shutter button (not shown) to designate the start of the operations of AF processing, AE processing, AWB processing, and EF processing. The shutter switch SW2 64 is turned ON by full stroke of the shutter button (not shown) to designate the start of a series of processing operations: exposure processing to write a signal read from the image sensing device 14 into the memory 30 via the A/D converter 16 and memory controller 22; development processing by using calculations by the image processor 20 and memory controller 22; and recording processing to read out image data from the memory 30, compress the image data by the compression/expansion circuit 32, and write the image data into the recording medium 200 or 210. The playback switch 66 designates the start of playback operation to read out a sensed image from the memory 30 or the recording medium 200 or 210 in an image sensing mode and display the image on the image display unit 28. The single-shot/sequential image sensing switch 68 allows setting a single-shot image sensing mode in which an image of one frame is sensed and then the device stands by when the shutter switch SW2 64 is pressed, and a sequential image sensing mode in which images are sequentially sensed while the shutter switch SW2 64 is kept pressed. The ISO sensitivity setting switch 69 enables setting an ISO sensitivity (image sensing sensitivity) by changing the gain setting in the image sensing device 14 or image processor 20. The operation unit 70 comprises various buttons and touch panels including a menu button, a set button, a macro button, a multi-image reproduction/repaging button, flash set button, a single-shot/sequential/- self-timer image sensing switching button, a forward (+) menu item selection button, a backward (−) menu item selection button, a forward (+) reproduction image search button, a backward (−) reproduction image search button, an image sensing quality selection button, an exposure correction button, a date/time set button, a selection/switching button for selecting and switching various functions in executing image sensing and reproduction in a panoramic mode or the like, a determination/execution button for setting determination and execution of various functions in executing image sensing and reproduction in a panoramic mode or the like, an image display ON/OFF switch to set the ON/OFF state of the image display unit 28, and a quick review ON/OFF switch to set a quick review function of automatically reproducing sensed image data immediately after image sensing. The operation unit 70 also comprises a compression mode switch to select the compression ratio of JPEG (Joint Photographic Experts Group) compression or select a CCDRAW mode in which a signal from the image sensing device 14 is directly digitized and recorded on a recording medium, a reproduction switch capable of setting function modes such as a reproduction mode, multi-image reproduction/erase mode, and PC (Personal Computer) connection mode, and an AF mode set switch capable of setting a one-shot AF mode in which, if the shutter switch SW1 62 is pressed, auto focus operation starts and once the image is in focus, the focus state is maintained, and a servo AF mode in which auto focus operation is kept performed while the shutter switch SW1 is kept pressed. With a rotary dial switch, numerical values and functions can be more easily selected for the “+” and “−” buttons. A power switch 72 allows switching and setting the power ON/OFF mode of the image processing apparatus 100. The power switch 72 also allows switching and setting the power ON/OFF settings of various accessory devices including the lens unit 300, external flash (not shown), and recording media 200 and 210 which are connected to the image processing apparatus 100. A power controller 80 comprises a battery detection circuit, a DC/DC converter, a switch circuit to switch a block to be energized, and the like. The power controller 80 detects the attached/detached state of the battery, a battery type, and a remaining battery power level, controls the DC/DC converter based on the results of detection and an instruction from the system controller 50, and supplies a necessary voltage to the respective parts including the recording media 200 and 210 for a necessary period. Connectors 82 and 84 connect the power controller 80 and a power source 86. The power source 86 comprises a primary battery such as an alkaline battery or lithium battery, a secondary battery such as an NiCd battery, NiMH battery, or Li battery, an AC adaptor, and the like. Interfaces 90 and 94 interface the recording media 200 and 210 such as a memory card and hard disk. Connectors 92 and 96 connect the image processing apparatus 100 and the recording media 200 and 210 such as a memory card and hard disk. A recording medium attached/detached state detector 98 detects whether the recording medium 200 and/or 210 is attached to the connector 92 and/or 96. In the first embodiment, two systems of interfaces and connectors for connection with the recording medium are employed. However, one or a plurality of systems of interfaces and connectors for connection with the recording medium may be provided. Further, interfaces and connectors pursuant to different standards may be combined. As the interfaces and connectors, cards in conformity with PCMCIA (Personal Computer Memory Card International Association) card standards and cards in conformity with CF (Compact Flash.RTM.) card standards may be used. In a case where cards and connectors in conformity with the PCMCIA standards, CF (Compact Flash.RTM.) card standards, and the like are used as the interfaces 90 and 94 and the connectors 92 and 96, image data and management information attached to the image data can be transferred between the image processing apparatus and other peripheral devices such as a computer and printer by connecting various communication cards such as a LAN card, modem card, USB (Universal Serial Bus) card, IEEE (Institute of Electrical and Electronics Engineers) 1394 card, P1284 card, SCSI (Small Computer System Interface) card, and PHS (Personal Handyphone System) card. The optical finder 104 can receive light incident on the lens 310 of the lens unit 300 via the stop 312, the lens mount 306, and the lens mount 106 and mirrors 130 and 132 of the image processing apparatus 100 in a single-lens reflex camera, forming and displaying an image as an optical image. An image can be sensed by using only the optical finder 104 without using any electronic finder function on the image display unit 28. A communication unit 110 has various communication functions for RS232C, USB, IEEE 1394, P1284, SCSI, modem, LAN, and wireless communication. A connector/antenna 112 functions as a connector when the image processing apparatus 100 is connected to another device via the communication unit 110, and as an antenna for wireless communication. An interface 120 connects the image processing apparatus 100 to the lens unit 300 at the lens mount 106. A connector 122 electrically connects the image processing apparatus 100 to the lens unit 300. A lens attached/detached state detector 124 detects whether the lens unit 300 is mounted on the lens mount 106 and/or connector 122. The connector 122 transfers a control signal, state signal, data signal, and the like between the image processing apparatus 100 and the lens unit 300, and also has a function of supplying currents of various voltages. The connector 122 may perform not only electrical communication but also optical communication and sound communication. The mirrors 130 and 132 can guide light incident on the lens 310 to the optical finder 104 in a single-lens reflex camera. Note that the mirror 132 may be a quick-return mirror or half-mirror. The recording medium 200 comprises a memory card, hard disk, or the like. The recording medium 200 has a recording unit 202 of a semiconductor memory, magnetic disk, or the like, an interface 204 for the image processing apparatus 100, and a connector 206 for connection with the image processing apparatus 100. Also, the recording medium 210 comprises a memory card, hard disk, or the like. The recording medium 210 has a recording unit 212 of a semiconductor memory, magnetic disk, or the like, an interface 214 for the image processing apparatus 100, and a connector 216 for connection with the image processing apparatus 100. The lens unit 300 is of interchangeable lens type. The lens mount 306 mechanically couples the lens unit 300 to the image processing apparatus 100. The lens mount 306 incorporates various functions for electrically connecting the lens unit 300 to the image processing apparatus 100. The image sensing lens 310 transmits an object image. The stop 312 adjusts the quantity of light entering from the image sensing lens 310. An interface 320 interfaces the lens unit 300 to the image processing apparatus 100 within the lens mount 306. A connector 322 electrically connects the lens unit 300 to the image processing apparatus 100. The connector 322 transfers a control signal, state signal, data signal, and the like between the image processing apparatus 100 and the lens unit 300, and also has a function of receiving or supplying currents of various voltages. The connector 322 may perform not only electrical communication but also optical communication and audio communication. The stop controller 340 controls the stop 312 on the basis of photometry information from the photometry unit 46 of the image processing apparatus 100 in association with the shutter controller 40 which controls the shutter 12. The distance measurement controller 342 controls focusing of the image sensing lens 310. A zoom controller 344 controls zooming of the image sensing lens 310. A lens system controller 350 controls the whole lens unit 300. The lens system controller 350 has as a memory which stores operation constants, variables, programs, and the like, and a nonvolatile memory which holds identification information such as a number unique to the lens unit 300, management information, pieces of function information such as a full-aperture f-number, minimum f-number, and focal length, and current and past set values. The operation of the image processing apparatus 100 with the above arrangement according to the first embodiment will be described in detail below with reference to FIGS. 1 to 6. <Whole Processing of Image Processing Apparatus 100> FIGS. 2 and 3 are flow charts showing the main routine of the image processing apparatus 100 according to the first embodiment. The operation of the image processing apparatus 100 will be described with reference to FIGS. 2 and 3. If the image processing apparatus 100 is powered ON by, e.g., replacing batteries, the system controller 50 initializes flags such as a single-shot/sequential image sensing flag and flash flag (to be described later), control variables, and the like, and performs predetermined initial settings necessary for the respective parts of the image processing apparatus 100 (step S101). The system controller 50 checks the set position of the power switch 72 (step S102). If the power switch 72 is set to power-OFF (“power OFF” in step S102), the system controller 50 performs predetermined end processing such that the display of each notification unit is changed to an end state, necessary parameters including flags and control variables, set values, and set modes are stored in the nonvolatile memory 56, and unnecessary power supplies of the respective parts of the image processing apparatus 100 including the image display unit 28 are turned OFF by the power controller 80 (step S103). After that, the process returns to step S102. If the power switch 72 is set to power-ON (“power ON” in step S102), the system controller 50 causes the power controller 80 to check whether the remaining capacity or operation status of the power source 86 formed from a battery or the like inhibits the operation of the image processing apparatus 100 (step S104). If the power source 86 has any problem (NO in step S104), the system controller 50 generates a predetermined warning display output or warning sound output by an image or sound using the notification unit 54 (step S105), and the process returns to step S102. If the power source 86 has no problem (YES in step S104), the system controller 50 checks the set position of the mode dial switch 60 (step S106). If the mode dial switch 60 is set to an image sensing mode (“image sensing mode” in step S106), the process advances to step S108. If the mode dial switch 60 is set to another mode (“another mode” in step S106), the system controller 50 executes processing corresponding to the selected mode (step S107), and after ending the processing, the process returns to step S102. If the mode dial switch 60 is set to the image sensing mode, the system controller 50 checks whether the recording medium 200 or 210 is mounted in the image processing apparatus 100, acquires management information of image data recorded on the recording medium 200 or 210, and checks whether the operation state of the recording medium 200 or 210 inhibits the operation of the image processing apparatus 100, particularly image data recording/reproduction operation with respect to the recording medium (step S108). If the recording medium 200 or 210 has any problem as a result of determination (NO in step S108), the system controller 50 generates a predetermined warning display output or warning sound output by an image or sound using the notification unit 54 (step S105), and the process returns to step S102. If the recording medium 200 or 210 has no problem as a result of determination (YES in step S108), the system controller 50 advances to step S109. The system controller 50 checks the set state of the single-shot/sequential image sensing switch 68 which sets single-shot/sequential image sensing (step S109). If single-shot image sensing has been selected, the system controller 50 sets the single-shot/sequential image sensing flag to single-shot image sensing (step S110), and if sequential image sensing has been selected, to sequential image sensing (step S111). After the flag is set, the process shifts to step S112. The single-shot image sensing mode in which an image of one frame is sensed and then the device stands by when the shutter switch SW2 64 is pressed, and the sequential image sensing mode in which images are sequentially sensed while the shutter switch SW2 64 is kept pressed can be arbitrarily switched and set by operating the single-shot/sequential image sensing switch 68. Note that the state of the single-shot/sequential image sensing flag is stored in the internal memory of the system controller 50 or the memory 52. The system controller 50 generates display outputs and sound outputs for various set states of the image processing apparatus 100 by images and sound using the notification unit 54 (step S112). If the image display of the image display unit 28 is ON, the system controller 50 also uses the image display unit 28 to generate display outputs and sound outputs for various set states of the image processing apparatus 100 by images and sound. The system controller 50 confirms the state of the shutter switch SW1 62 (step S121), and if the shutter switch SW1 62 is not pressed (“OFF” in step S121), the process returns to step S102. If the shutter switch SW1 62 is pressed (“ON” in step S121), the system controller 50 performs distance measurement/photometry processing of focusing the image sensing lens 310 on an object to be sensed by distance measurement processing, and determining an f-number and shutter time by photometry processing (step S122). Thereafter, the process shifts to step S123. In photometry processing, the flash is also set, as needed. Details of distance measurement/photometry processing will be explained later with reference to FIG. 4. The system controller 50 reads out from the nonvolatile memory 56 one-dimensional correction data used for horizontal dark shading correction, and maps the data in the memory 30. At the end of mapping the one-dimensional correction data, the system controller 50 captures a dark image in the use of the one-dimensional correction data (meaning an accumulated charge output from the image sensing device 14 while keeping the shutter 12 closed). The system controller 50 changes the mapped correction data in accordance with the state of the dark image (step S123). Details of step S123 will be described later with reference to FIG. 6. The system controller 50 confirms the state of the shutter switch SW2 64 (step S124). If the shutter switch SW2 64 is not pressed (“OFF” in step S124), the process shifts to step S125, and if the shutter switch SW1 62 is not pressed, too, immediately returns to step S102. If the shutter switch SW1 62 is pressed, the process returns to step S124. If the shutter switch SW2 64 is pressed (“ON” in step S124), the system controller 50 checks whether the memory 30 has an image storage buffer area capable of storing image data sensed in the second image sensing mode (step S126). If the image storage buffer area of the memory 30 does not have any area capable of storing new image data (NO in step S126), the system controller 50 generates a predetermined warning display output or warning sound output by an image or sound using the notification unit 54 (step S127), and the process returns to step S102. This situation occurs when, for example, the first image which should be read out from the memory 30 and written into the recording medium 200 or 210 has not been recorded yet on the recording medium 200 or 210, and no free area even for one image can be ensured in the image storage buffer area of the memory 30 immediately after sequential image sensing by the maximum number of images which can be stored in the image storage buffer area of the memory 30. To store sensed image data in the image storage buffer area of the memory 30 after compression, whether the storage area can be ensured in the image storage buffer area of the memory 30 is checked in step S126 in consideration of the fact that the compressed image data amount changes depending on the settings of the compression mode. If the memory 30 has an image storage buffer area capable of storing sensed image data (YES in step S126), the system controller 50 executes image sensing processing of reading from the image sensing device 14 a sensed image signal accumulated for a predetermined time, and writing the sensed image data into a predetermined area of the memory 30 via the A/D converter 16, image processor 20, and memory controller 22, or via the memory controller 22 directly from the A/D converter 16 (step S128). Details of image sensing processing step S128 will be described later with reference to FIG. 5. The system controller 50 reads out via the memory controller 22 part of image data written in the predetermined area of the memory 30, performs WB (White Balance) integral calculation processing and OB (Optical Black) integral calculation processing necessary for developing processing, and stores the results of calculations in the internal memory of the system controller 50 or the memory 52. The system controller 50 reads out the sensed image data written in the predetermined area of the memory 30 by using the memory controller 22, and if necessary, the image processor 20. Also, the system controller 50 executes various developing processes including AWB (Auto White Balance) processing, gamma conversion processing, and color conversion processing by using the results of calculations stored in the internal memory of the system controller 50 or the memory 52 (step S129). In developing processing, the system controller 50 also executes dark correction calculation processing of canceling the dark current noise of the image sensing device 14 or the like by subtraction processing using the correction data which has been mapped and changed in step S123 in accordance with the state of the dark image data. By dark correction calculation processing using horizontal dark shading correction data, sensed image data can be corrected for image quality degradation caused by horizontal dark current noise or fixed pattern noise in the image sensing device 14, without performing dark image capturing processing for a sensed image in the entire image sensing region. The system controller 50 reads out the image data written in the predetermined area of the memory 30, and performs image compression processing corresponding to the set mode by the compression/expansion circuit 32 (step S130). The system controller 50 writes the image data having undergone a series of processes into a free portion of the image storage buffer area of the memory 30. Along with execution of a series of image sensing processes, the system controller 50 reads out the image data stored in the image storage buffer area of the memory 30, and writes the data into the recording medium 200 or 210 such as a memory card or Compact Flash.RTM. card via the interface 90 or 94 and the connector 92 or 96 (step S131). Recording processing is executed every time image data having undergone a series of processes is newly written into a free portion of the image storage buffer area of the memory 30. During write of image data into the recording medium 200 or 210, an LED, for instance, of the notification unit 54 is flickered in order to explicitly indicate that write operation is in progress. The system controller 50 checks whether the shutter switch SW1 62 is pressed (step S132), and if the shutter switch SW1 62 is not pressed, the process returns to step S102. If the shutter switch SW1 62 is pressed, the system controller 50 checks the state of the single-shot/sequential image sensing flag stored in the internal memory of the system controller 50 or the memory 52 (step S133). If single-shot image sensing has been set, the process returns to step S132 and waits until the shutter switch SW1 62 is turned off. If sequential image sensing has been set, the process returns to step S124 and prepares for image sensing of the next frame. A series of image sensing processes then end. <Distance Measurement/Photometry Processing> FIG. 4 is a flow chart showing details of distance measurement/photometry processing in step S122 of FIG. 3. In distance measurement/photometry processing, various signals are exchanged between the system controller 50 of the image processing apparatus 100 and the stop controller 340 or distance measurement controller 342 of the lens unit 300 via the interface 120, connector 122, connector 322, interface 320, and lens controller 350. The system controller 50 starts AF processing by using the image sensing device 14, the distance measurement unit 42, and the distance measurement controller 342 of the lens unit 300 (step S201). The system controller 50 executes AF control (step S202). More specifically, light incident on the lens 310 of the lens unit 300 is guided to enter the distance measurement unit 42 via the stop 312, the lens mount 306, and the lens mount 106, mirror 130, and distance measurement sub-mirror (not shown) of the image processing apparatus 100, thereby checking the focus state of an image formed as an optical image. While the lens 310 is driven by using the distance measurement controller 342 of the lens unit 300 until the image is determined to be in focus by distance measurement (AF) (YES in step S203), the focus state is detected by using the distance measurement unit 42 of the image processing apparatus 100 (step S202). If the image is determined to be in focus by distance measurement (AF) (YES in step S203), the system controller 50 determines a distance measurement point where the image is in focus from a plurality of distance measurement points within the image frame (step S204). The system controller 50 stores distance measurement data and set parameters (or either of distance measurement data and set parameters) in the internal memory of the system controller 50 or the memory 52 together with the determined distance measurement point data, and the process advances to step S205. The system controller 50 starts AE (Auto Exposure) processing by using the photometry unit 46 (step S205). The system controller 50 causes light incident on the lens 310 of the lens unit 300 to enter the photometry unit 46 via the stop 312, the lens mount 306, and the lens mount 106, mirrors 130 and 132, and photometry lens (not shown) of the image processing apparatus 100, thereby measuring the exposure state of an image formed as an optical image. The system controller 50 performs photometry processing by using the shutter controller 40 until exposure is determined to be proper (YES in step S207) (step S206). If exposure is determined to be proper (YES in step S207), the system controller 50 stores photometry data and set parameters (or either of photometry data and set parameters) in the internal memory of the system controller 50 or the memory 52, and advances to step S208. The system controller 50 determines an f-number (Av value) and shutter speed (Tv value) in accordance with the exposure (AE) result detected in photometry processing step S206 and an image sensing mode set by the mode dial switch 60. The system controller 50 determines the charge accumulation time of the image sensing device 14 in accordance with the determined shutter speed (Tv value), and performs image sensing processing and dark capturing processing for the same charge accumulation time. The system controller 50 determines from measurement data obtained in photometry processing step S206 whether the flash is required (step S208). If the flash is not required, the system controller 50 clears the flash flag, and ends distance measurement/photometry processing routine step S122 (FIG. 3). If the flash is required, the flash flag is set, and the flash 48 is charged (step S209) until the flash 48 is fully charged (step S210). If the flash 48 has been charged (YES in step S210), the system controller 50 ends the distance measurement/photometry processing routine (step S122 of FIG. 3). <Image Sensing Processing> FIG. 5 is a flow chart showing details of image sensing processing in step S128 of FIG. 3. In image sensing processing, various signals are exchanged between the system controller 50 of the image processing apparatus 100 and the stop controller 340 or distance measurement controller 342 of the lens unit 300 via the interface 120, connector 122, connector 322, interface 320, and lens controller 350. The system controller 50 moves the mirror 130 to a predetermined position (mirror-up position) outside the optical axis by a mirror driving unit (not shown) (step S301). The system controller 50 drives the stop 312 to a predetermined f-number by the stop controller 340 in accordance with photometry data stored in the internal memory of the system controller 50 or the memory 52 (step S302). The system controller 50 executes charge clear operation for the image sensing device 14 (step S303). After charge accumulation in the image sensing device 14 starts (step S304), the system controller 50 opens the shutter 12 by the shutter controller 40 (step S305), and starts exposure of the image sensing device 14 (step S306). The system controller 50 determines from the flash flag whether the flash 48 is required (step S307), and if the flash 48 is required, causes the flash 48 to emit light (step S308). The system controller 50 waits for the end of exposure of the image sensing device 14 in accordance with photometry data (step S309), closes the shutter 12 by the shutter controller 40 (step S310), and ends exposure of the image sensing device 14. The system controller 50 drives the stop 312 to a full-aperture f-number by the stop controller 340 of the lens unit 300 (step S311), and moves the mirror 130 to a predetermined position (mirror-down position) within the optical axis by the mirror driving unit (not shown) (step S312). Upon the lapse of a set charge accumulation time (YES in step S313), the system controller 50 ends charge accumulation in the image sensing device 14 (step S314). The system controller 50 reads a charge signal from the image sensing device 14, and writes sensed image data into a predetermined area of the memory 30 via the A/D converter 16, image processor 20, and memory controller 22, or via the memory controller 22 directly from the A/D converter 16 (step S315). After a series of processes end, the system controller 50 ends the image sensing processing routine (step S128 of FIG. 3). <Correction Data Change Processing> FIG. 6 is a flow chart showing details of correction data change processing in step S123 of FIG. 3. The system controller 50 of the image processing apparatus 100 reads out from the nonvolatile memory 56 one-dimensional correction data (to be referred to as “correction data” hereinafter) used for horizontal dark shading correction, and maps the data in the memory 30 (step S401). The system controller 50 executes charge clear operation for the image sensing device 14 (step S402), and starts charge accumulation in the image sensing device 14 in the first image sensing mode while keeping the shutter 12 closed (step S403). Upon the lapse of a set charge accumulation time (YES in step S404), the system controller 50 ends charge accumulation in the image sensing device 14 (step S405). The system controller 50 reads out a charge signal from the image sensing device 14, and writes only image data of a predetermined region (e.g., several lines) as part of the image sensing device 14 into a predetermined area of the memory 30 via the A/D converter 16, image processor 20, and memory controller 22, or via the memory controller 22 directly from the A/D converter 16 (step S406). The system controller 50 performs horizontal dark shading correction processing for the image data written in the memory 30 by using the correction data read out from the nonvolatile memory 56 (step S407). The system controller 50 calculates a dark level from the image data having undergone horizontal dark shading correction processing (step S408). As a calculation method, e.g., the average value of image data having undergone horizontal dark shading correction processing is calculated and used. If the dark level calculated in step S408 is not an allowable value (“outside allowable range” in step S409), the dark level varies under the influence of the ambient temperature on the output circuit (not shown) of the image sensing device 14. Thus, the system controller 50 changes the correction data so as to make the calculated dark level reach an allowable value (step S410), and ends the correction data change processing routine. Note that the change of correction data means the change of mainly the offset amount of correction data. Depending on the correction method, only the correction coefficient or both the offset amount and correction coefficient of correction data may be changed. The correction data is such data as to cancel a dark current component of the image sensing device 14 and the FPN (Fixed Pattern Noise) of the circuit system. If the dark level calculated in step S408 is an allowable value (“within allowable range” in step S409), the dark level falls within a proper range without any influence of the ambient temperature on the image sensing device 14. The system controller 50 therefore ends the correction data change processing routine without changing correction data. As described above, according to the first embodiment, image data which is obtained in the first image sensing mode and referred to in order to change correction data is data read from not the entire region but a predetermined region of the image sensing device 14, and this image data read time is very short. Even if the characteristic of the image sensing system changes under the influence of the ambient temperature, an increase in the release time lag along with dark image sensing can be prevented, compared to a case wherein correction data is not changed. Correction data is changed in accordance with image data obtained in the first image sensing mode every image sensing, and image data obtained in the second image sensing mode is corrected using the changed correction data. Even if the dark current noise of the image sensing device 14 nonlinearly changes depending on the temperature characteristic of the output circuit, the noise component can be easily canceled, preventing image quality degradation and obtaining a high-quality image. In the first embodiment, correction data for horizontal dark shading correction is mapped (step S401 of FIG. 6) after the shutter switch SW1 62 is pressed. Alternatively, correction data may be mapped after power-ON of the image processing apparatus. In the first embodiment, correction data is one-dimensional horizontal data, but may be one-dimensional vertical data or two-dimensional data. In the first embodiment, correction data is changed (step S123 of FIG. 3) after the shutter switch SW1 62 is pressed. Alternatively, correction data may be changed immediately before image sensing (immediately before step S129 of FIG. 3) after the shutter switch SW2 64 is pressed. In the first embodiment, processing of changing correction data (step S123 of FIG. 3) is performed regardless of the ambient temperature. Processing of correction data may be performed only when the ambient temperature falls outside a predetermined range. The predetermined range is an ambient temperature range where the output of the image sensing device 14 is free from any influence and horizontal dark shading correction data need not be changed. Second Embodiment The second embodiment of the present invention realizes effective shading correction even when the shading of an image sensing device changes depending on image sensing conditions (image sensing ISO (International Organization for Standardization) sensitivity) in an image processing apparatus such as an electronic camera. The second embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The arrangement of an image processing apparatus in the second embodiment is the same as that in the first embodiment shown in FIG. 1, and a description thereof will be omitted. In the second embodiment, a nonvolatile memory 56 stores various parameters, set values such as the image sensing ISO sensitivity, set modes, one-dimensional shading correction data at a reference image sensing ISO sensitivity that is used for horizontal dark shading correction, and a gain amount and offset amount corresponding to each image sensing ISO sensitivity. One-dimensional shading correction data is created and written in adjustment during the manufacturing process of the image processing apparatus. Alternatively, one-dimensional shading correction data may be generated based on a dark image captured right after the image processing apparatus is powered ON. FIG. 7 is a block diagram showing the arrangement of the main part of the image processing apparatus according to the second embodiment. The image processing apparatus comprises an image sensing lens 1 (310 in FIG. 1), a solid-state image sensing device 2 (14 in FIG. 1), an A/D converter 3 (16 in FIG. 1), a timing generator 4 (18 in FIG. 1), a memory controller 5 (22 in FIG. 1), an image processor 6 (20 in FIG. 1), a system controller 7 (50 in FIG. 1), and a nonvolatile memory 8 (56 in FIG. 1). The image sensing lens 1 forms an optical image of an object to be sensed onto the solid-state image sensing device 2. The solid-state image sensing device 2 converts the formed image data into an electrical signal. The A/D converter 3 A/D-converts an output signal from the solid-state image sensing device 2. The timing generator 4 determines the operation timings of the solid-state image sensing device 2 and A/D converter 3. The memory controller 5 controls the A/D converter 3, timing generator 4, image processor 6, and nonvolatile memory 8. The image processor 6 performs predetermined pixel interpolation processing and color conversion processing on data from the A/D converter 3 or data from the memory controller 5. The system controller 7 controls the overall image processing apparatus. The nonvolatile memory 8 is an electrically erasable and recordable memory, and stores various parameters, set values such as the ISO sensitivity, set modes, one-dimensional shading correction data at a reference image sensing ISO sensitivity that is used for horizontal dark shading correction, and a gain amount and offset amount corresponding to each image sensing ISO sensitivity. The operation of the image processing apparatus with the above arrangement according to the second embodiment will be described in detail below. <Whole Processing of Image Processing Apparatus 100> The whole processing of an image processing apparatus 100 in the second embodiment will be explained. A description of processing from steps S101 to S112 in FIG. 2 which is the same as that in the first embodiment will be omitted. Processing after step S112 will be described with reference to FIGS. 8 and 9. If a shutter switch SW1 62 is not pressed in step S521 of FIG. 8 (“OFF” in step S521), the flow returns to step S102 in FIG. 2. If the shutter switch SW1 62 is pressed (“ON” in step S521), a system controller 50 performs distance measurement/photometry processing of focusing the image sensing lens 1 on an object to be sensed by distance measurement processing, and determining an f-number and shutter time by photometry processing (step S522). The process then shifts to step S523. In photometry processing, the flash is also set, as needed. Details of distance measurement/photometry processing step S522 is the same as the processes described with reference to FIG. 4 in the above first embodiment, thus the detailed explanation of step S522 is omitted. The system controller 50 checks the set sensitivity of the image processing apparatus 100 (step S523). If the set sensitivity is lower than ISO 800, the process advances to step S524; if the set sensitivity is equal to or higher than ISO 800, to step S527. This is because the exposure amount is small, and image quality degradation by dark current noise generated by an image sensing device 14, a defective pixel due to a slight scratch unique to the image sensing device 14, or the like becomes conspicuous. In this case, the threshold to determine the set sensitivity is ISO 800, but may be ISO 1600 for a small sensor dark current. The system controller 50 checks whether the set sensitivity is lower than ISO 400 (step S524). If the set sensitivity is lower than ISO 400, the process shifts to step S530; if the set sensitivity is equal to or higher than ISO 400, to step S525. The system controller 50 checks whether a temperature Temp in the image sensing environment that is detected by a thermometer 44 is lower than 28.degree. C. (step S525). If the temperature Temp is lower than 28.degree. C., the process shifts to step S530; if the temperature Temp is equal to or higher than 28.degree. C., to step S526. The system controller 50 checks whether the shutter time Tv determined in distance measurement/photometry processing (step S522) is equal to or longer than 1 sec (step S526). If the shutter time is 1 sec or more, the system controller 50 sets a dark subtraction flag to 1 (step S527), and the process advances to step S528. If the shutter time is shorter than 1 sec. the system controller 50 clears the dark subtraction flag to 0 (step S530), and the process advances to step S531. After the dark subtraction flag is cleared, correction data corresponding to the image sensing ISO sensitivity is mapped (step S531). Details of correction data mapping processing step S531 will be described later with reference to FIG. 11. Note that “dark subtraction” is calculation processing of subtracting dark image data from image data of actual image sensing (see “BACKGROUND OF THE INVENTION”). After the dark subtraction flag is set, the system controller 50 checks a single-shot/sequential image sensing flag stored in the internal memory of the system controller 50 or a memory 52 (step S528). If single-shot image sensing has been set, the system controller 50 shifts to step S540; if sequential image sensing has been set, captures a dark image (step S529) and the process shifts to step S540. (By performing correction calculation processing using dark image data captured by dark image capturing processing, sensed image data can be corrected for image quality degradation caused by dark current noise generated by the image sensing device 14, a defective pixel due to a slight scratch unique to the image sensing device 14, or the like. Details of dark image capturing processing step S529 will be described with reference to FIG. 10.) If a shutter switch SW2 64 is not pressed (“OFF” in step S540), the process returns to step S521 and repeats processing up to step S540. If the shutter switch SW2 64 is pressed (“ON” in step S540), the system controller 50 checks whether a memory 30 has an image storage buffer area capable of storing sensed image data (step S542). If the image storage buffer area of the memory 30 does not have any area capable of storing new image data (NO in step S542), the system controller 50 generates a predetermined warning display output or warning sound output by an image or sound using a notification unit 54 (step S544), and the process returns to step S102 in FIG. 2. This situation occurs when, for example, the first image which should be read out from the memory 30 and written into a recording medium 200 or 210 has not been recorded yet on the recording medium 200 or 210, and no free area even for one image can be ensured in the image storage buffer area of the memory 30 immediately after sequential image sensing by the maximum number of images which can be stored in the image storage buffer area of the memory 30. To store sensed image data in the image storage buffer area of the memory 30 after compression, whether the storage area can be ensured in the image storage buffer area of the memory 30 is checked in step S542 in consideration of the fact that the compressed image data amount changes depending on the settings of the compression mode. If the memory 30 has an image storage buffer area capable of storing sensed image data (YES in step S542), the system controller 50 executes image sensing processing of reading from the image sensing device 14 an image sensing signal accumulated for a predetermined time, and writing the sensed image data into a predetermined area of the memory 30 via an A/D converter 16, image processor 20, and memory controller 22, or via the memory controller 22 directly from the A/D converter 16 (step S546). In image sensing processing step S546, the processing described with reference to FIG. 5 in the above first embodiment is performed, and thus the detailed description of the step S546 is omitted. After image sensing processing step S546 ends, the system controller 50 checks the state of the dark subtraction flag stored in the internal memory of the system controller 50 or the memory 52 (step S548). If no dark subtraction flag has been set, the process shifts to step S554. If the dark subtraction flag has been set, the system controller 50 checks the state of the single-shot/sequential image sensing flag stored in the internal memory of the system controller 50 or the memory 52 (step S550). If single-shot image sensing has been set, the process advances to step S552; if sequential image sensing has been set, to step S554. In single-shot image sensing setting, the system controller 50 performs dark capturing processing of accumulating a noise component such as the dark current of the image sensing device 14 for the same time as that of actual image sensing while keeping a shutter 12 closed, and reading the accumulated noise image signal (step S552). After that, the process shifts to step S554. Details of dark capturing processing step S552 will be described with reference to FIG. 10. The system controller 50 reads out via the memory controller 22 part of image data written in a predetermined area of the memory 30, performs WB (White Balance) integral calculation processing and OB (Optical Black) integral calculation processing necessary for developing processing, and stores the results of calculations in the internal memory of the system controller 50 or the memory 52. The system controller 50 reads out the sensed image data written in the predetermined area of the memory 30 by using the memory controller 22, and if necessary, the image processor 20. Also, the system controller 50 executes various developing processes including AWB (Auto White Balance) processing, gamma conversion processing, and color conversion processing by using the results of calculations stored in the internal memory of the system controller 50 or the memory 52 (step S554). In developing processing, the system controller 50 also executes dark correction calculation processing of canceling the dark current noise of the image sensing device 14 or the like by subtraction processing using horizontal dark shading correction data which corresponds to the image sensing ISO sensitivity value and has been mapped in step S531, or dark image data captured in dark image capturing processing (step S529 or S552). By correction calculation processing using horizontal dark shading correction data, a sensed image can be corrected for image quality degradation caused by horizontal dark current noise or fixed pattern noise in the image sensing device 14, without performing dark image capturing processing (step S529 or S552) for a sensed image. By correction calculation processing using dark image data obtained in dark image capturing processing, sensed image data can be corrected for image quality degradation caused by a two-dimensional factor such as a defective pixel due to a slight scratch unique to the image sensing device 14, in addition to horizontal dark current noise or fixed pattern noise in the image sensing device 14. The system controller 50 reads out the image data written in the predetermined area of the memory 30, and performs image compression processing corresponding to the set mode by a compression/expansion circuit 32 (step S556). The system controller 50 writes the image data having undergone a series of processes into a free portion of the image storage buffer area of the memory 30. Along with execution of a series of image sensing processes, the system controller 50 reads out the image data stored in the image storage buffer area of the memory 30, and writes the data into the recording medium 200 or 210 such as a memory card or Compact Flash.RTM. card via an interface 90 or 94 and a connector 92 or 96 (step S558). Recording processing on the recording medium 200 or 210 is executed for image data every time image data having undergone a series of processes is newly written into a free portion of the image storage buffer area of the memory 30. During write of image data into the recording medium 200 or 210, an LED, for instance, of the notification unit 54 flickered to explicitly indicate that write operation is in progress. The system controller 50 checks whether the shutter switch SW1 62 is pressed (step S560), and if the shutter switch SW1 62 is OFF, the process returns to step S102 in FIG. 2. If the shutter switch SW1 62 is ON, the system controller 50 checks the single-shot/sequential image sensing flag stored in the internal memory of the system controller 50 or the memory 52 (step S562). If single-shot image sensing has been set, the system controller 50 returns to step S560; if sequential image sensing has been set, returns to step S540 and repeats the above-described operation. <Dark Image Capturing Processing> FIG. 10 is a flow chart showing details of dark image capturing processing in step S529 of FIG. 8 and step S552 of FIG. 9. The system controller 50 of the image processing apparatus 100 executes charge clear operation for the image sensing device (CCD) 14 (step S601), and starts charge accumulation in the image sensing device 14 while keeping the shutter 12 closed (step S602). Upon the lapse of a set charge accumulation time (YES in step S603), the system controller 50 ends charge accumulation in the image sensing device 14 (step S604). The system controller 50 reads a charge signal from the image sensing device 14, and writes image data (dark image data) into a predetermined area of the memory 30 via the A/D converter 16, image processor 20, and memory controller 22, or via the memory controller 22 directly from the A/D converter 16 (step S605). The dark image data is used in developing processing when image sensing processing is executed before the dark image data is captured and sensed image data is read from the image sensing device 14 and written into the memory 30, and in developing processing when image sensing processing is executed after the dark image data is captured and sensed image data is read from the image sensing device 14 and written into the memory 30. By developing processing using the dark image data, sensed image data can be corrected for image quality degradation caused by dark current noise generated by the image sensing device 14, a defective pixel due to a slight scratch unique to the image sensing device 14, or the like. At the end of a series of processes, dark image capturing processing routine step S529 (FIG. 8) and step S552 (FIG. 9) end. <Correction Data Mapping Processing> FIG. 11 is a flow chart showing details of correction data mapping processing in step S531 of FIG. 8. The system controller 50 of the image processing apparatus 100 reads out from the nonvolatile memory 56 one-dimensional shading correction data which is obtained at a reference image sensing ISO sensitivity value and serves as reference data for one-dimensional shading correction data used for horizontal shading correction. The system controller 50 maps the one-dimensional shading correction data in the memory 30 (step S701). The system controller 50 reads out an image sensing ISO sensitivity value set in the internal memory of the system controller 50 or the memory 52 (step S702). The system controller 50 reads out a gain amount and offset amount corresponding to the readout image sensing ISO sensitivity value from the nonvolatile memory 56, and maps them in the memory 30 (step S703). The system controller 50 calculates one-dimensional shading correction data, mapped in the memory 30, corresponding to the image sensing ISO sensitivity by arithmetic calculation using the one-dimensional shading correction data at the reference image sensing ISO sensitivity and the gain amount and offset amount corresponding to each image sensing ISO sensitivity (step S704). FIGS. 12A to 12C are graphs showing the outline of arithmetic calculation processing in step S704. In FIG. 12A, the solid line represents one-dimensional shading correction data at the reference image sensing ISO sensitivity value that is mapped in the memory 30 in step S701. In FIG. 12B, the chain double-dashed line represents one-dimensional shading correction data at the reference ISO sensitivity. The solid line represents the calculation result of multiplying by the gain amount the one-dimensional shading correction data at the reference ISO sensitivity that is represented by the chain double-dashed line. In FIG. 12C, the chain double-dashed line represents one-dimensional shading correction data at the reference ISO sensitivity. The broken line represents the calculation result of multiplication by the gain. The solid line represents the result of adding/subtracting the offset amount to/from the broken-line calculation result of multiplying by the gain amount the one-dimensional shading correction data at the reference ISO sensitivity. That is, solid-line data is one-dimensional shading correction data corresponding to the image sensing ISO sensitivity. The system controller 50 maps in the memory 30 the one-dimensional shading correction data which corresponds to the image sensing ISO sensitivity and has been calculated in step S704 (step S705). By developing processing using the shading correction data corresponding to the image sensing ISO sensitivity, sensed image data can be corrected for image quality degradation caused by horizontal dark current noise or fixed pattern noise in the image sensing device 14. At the end of a series of processes, mapping processing routine step S531 (FIG. 8) for one-dimensional shading correction data ends. <Image Sensing Operation Flow> FIG. 13 is an explanatory view showing an image sensing operation flow according to the second embodiment. AF processing, AE processing, image sensing processing, and dark image capturing processing in FIG. 13 are the same as those described with reference to FIGS. 4 and 5, FIGS. 2, 8 and 9, and FIG. 10, respectively, and a description thereof will be omitted. As described above, according to the second embodiment of the present invention, shading correction data at a reference image sensing ISO sensitivity, and a gain amount and offset amount at each image sensing ISO sensitivity are stored in the nonvolatile memory 56 in an image processing apparatus which records a sensed still image and/or moving image on a recording medium. Even if the shading changes upon the change in image sensing ISO sensitivity, effective shading correction processing can be done. It suffices to store, in the nonvolatile memory 56 for each image sensing ISO sensitivity, shading correction data at a reference image sensing ISO sensitivity and a gain amount and offset amount which are much smaller in data amount than the shading correction data. The capacity of the nonvolatile memory 56 can be greatly saved in comparison with a method of storing shading correction data at all image sensing ISO sensitivities in a storage medium. In the description of the first and second embodiments, single-shot/sequential image sensing is switched using the single-shot/sequential image sensing switch 68. Alternatively, single-shot/sequential image sensing may be switched in accordance with operation mode selection by a mode dial switch 60. In the description of the above embodiments, the charge accumulation time of actual image sensing processing and that of dark image capturing processing are equal to each other. However, different charge accumulation times may be adopted as far as data enough to correct dark current noise or the like can be obtained. No image sensing operation can be done during execution of dark capturing processing operation in steps S524 and S531 of FIG. 8. A notification unit 54 and/or image display unit 28 may output an image or sound representing that an image processing apparatus 100 is busy. In the description of the first and second embodiments, image sensing operation is performed by moving the mirror 130 to a mirror-up position or mirror-down position. It is also possible to form a mirror 130 from a half-mirror and perform image sensing operation without moving the mirror 130. In the description of the first and second embodiments, the recording media 200 and 210 are memory cards such as a PCMCIA card or Compact Flash.RTM., hard disks, or the like. Recording media 200 and 210 may also be formed from optical disks such as a micro DAT, magneto-optical disk, CD-R, or CD-RW, or phase change optical disks such as a DVD. The recording media 200 and 210 may also be composite media of memory cards and hard disks. Part of the composite medium may be detachable. In the description of the first and second embodiments, the recording media 200 and 210 are separated from the image processing apparatus 100 and are arbitrarily connectable to it. Either or both of the recording media may be fixed to the image processing apparatus 100. The image processing apparatus 100 may be so constituted as to allow connecting one or an arbitrary number of recording media 200 or 210. In the description of the first and second embodiments, the recording media 200 and 210 are mounted in the image processing apparatus 100. However, one or a plurality of recording media may be mounted. The second embodiment does not particularly mention the mapping timing of one-dimensional shading correction data. Correction data may be mapped upon power-ON. Correction data is one-dimensional horizontal data, but may be one-dimensional vertical data or two-dimensional data. Further, only one correction data is stored, but a plurality of correction data may be stored. For a plurality of correction data, a method of selecting only one of a plurality of correction data, or a method of adding a plurality of correction data at an arbitrary ratio may be employed. Correction data is created and written in adjustment during the manufacturing process of the image processing apparatus, but the write stage is not limited to the manufacturing process. Other Embodiment The present invention can be applied to a system constituted by a plurality of devices or to an apparatus comprising a single device. Further, the object of the present invention can also be achieved by providing a storage medium storing program codes for performing the aforesaid processes to a computer system or apparatus (e.g., a personal computer), reading the program codes, by a CPU or MPU of the computer system or apparatus, from the storage medium, then executing the program. In this case, the program codes read from the storage medium realize the functions according to the embodiments, and the storage medium storing the program codes constitutes the invention. Further, the storage medium, such as a floppy disk, a hard disk, an optical disk, a magneto-optical disk, CD-ROM, CD-R, a magnetic tape, a non-volatile type memory card, and ROM, and computer network, such as LAN (local area network) and WAN (wide area network), can be used for providing the program codes. Furthermore, besides aforesaid functions according to the above embodiments are realized by executing the program codes which are read by a computer, the present invention includes a case where an OS (operating system) or the like working on the computer performs a part or entire processes in accordance with designations of the program codes and realizes functions according to the above embodiments. Furthermore, the present invention also includes a case where, after the program codes read from the storage medium are written in a function expansion card which is inserted into the computer or in a memory provided in a function expansion unit which is connected to the computer, CPU or the like contained in the function expansion card or unit performs a part or entire process in accordance with designations of the program codes and realizes functions of the above embodiments. In a case where the present invention is applied to the aforesaid storage medium, the storage medium stores program codes corresponding to the flowcharts shown in FIGS. 2-6, or FIGS. 2, 4, 5, 8-11 described in the embodiments. Further, the above embodiments or the technical elements thereof may be combined as necessary. The present invention is not limited to the above embodiments and various changes and modifications can be made within the spirit and scope of the present invention. Therefore to apprise the public of the scope of the present invention, the following claims are made.
|
H
|
H04
|
H04N
|
52
|
17
|
|||
11803447
|
US20080066662A1-20080320
|
Novel gauge wheel for use with a conventional row planter assembly
|
ACCEPTED
|
20080305
|
20080320
|
[]
|
A01C506
|
["A01C506"]
|
8104543
|
20070515
|
20120131
|
172
|
610000
|
99684.0
|
NOVOSAD
|
CHRISTOPHER
|
[{"inventor_name_last": "Hesla", "inventor_name_first": "Ron", "inventor_city": "Wakonda", "inventor_state": "SD", "inventor_country": "US"}]
|
A row planter assembly comprising: a frame; an opening disk rotatably mounted to the frame; and a gauge wheel rotatably mounted to the frame and disposed alongside, but spaced from, the opening disk so as to create a narrow gap therebetween; wherein the gauge wheel comprises at least one opening in the side wall thereof so as to permit soil to pass from the gap located between the opening disk and the gauge wheel to the region outside of the gauge wheel.
|
1. A row planter assembly comprising: a frame; an opening disk rotatably mounted to the frame; and a gauge wheel rotatably mounted to the frame and disposed alongside, but spaced from, the opening disk so as to create a narrow gap therebetween; wherein the gauge wheel comprises at least one opening in the side wall thereof so as to permit soil to pass from the gap located between the opening disk and the gauge wheel to the region outside of the gauge wheel. 2. A row planter assembly according to claim 1 wherein each of the at least one openings extends along at least 30% of the radius of the gauge wheel. 3. A row planter assembly according to claim 1 wherein each of the at least one openings extends along at least 50 degrees of the circumference of the gauge wheel. 4. A row planter assembly according to claim 1 wherein the gauge wheel comprises two openings. 5. A row planter assembly according to claim 4 wherein the two openings are diametrically opposed from one another. 6. A row planter assembly according to claim 1 wherein the assembly further comprises a scraper disposed in the gap between the opening disk and the gauge wheel and configured to remove soil from at least one of the opening disk and the gauge wheel and direct the removed soil out the at least one opening. 7. A row planter assembly according to claim 6 wherein the scraper comprises a surface for removing soil from the opening disk. 8. A row planter assembly according to claim 6 wherein the scraper comprises a surface for removing soil from the gauge wheel. 9. A row planter assembly according to claim 6 wherein the scraper comprises a curved body for directing the removed soil out the at least one opening. 10. A row planter assembly according to claim 6 wherein the scraper comprises a first surface for removing soil from the opening disk, a second surface for removing soil from the gauge wheel, and a curved body for directing the removed soil out the at least one opening. 11. A row planter assembly according to claim 6 wherein the scraper is mounted to the frame. 12. A row planter assembly according to claim 6 wherein the opening disk is rotatably mounted to the frame via an axle, and further wherein the scraper is mounted to the opening disk axle. 13. A row planter assembly according to claim 6 wherein the gauge wheel is rotatably mounted to the frame via an axle, and further wherein the scraper is mounted to the gauge wheel axle. 14. A row planter assembly according to claim 6 wherein the gauge wheel comprises at least one wheel liner disposed adjacent to the at least one opening, wherein the wheel liner comprises an inner rim surface to facilitate the egress of soil out the at least one opening. 15. A row planter assembly according to claim 6 wherein the gauge wheel comprises at least one soil deflector disposed adjacent to the at least one opening, wherein the soil deflector is positioned along a trailing edge of the at least one opening so as to facilitate the egress of soil out the at least one opening. 16. A row planter assembly according to claim 6 wherein the gauge wheel comprises at least one soil exit chute disposed adjacent to the at least one opening, wherein the soil exit chute comprises a floor and a side wall configured to move soil outboard as it emerges from the at least one opening. 17. A row planter assembly comprising: a frame; an opening disk rotatably mounted to the frame; a gauge wheel rotatably mounted to the frame and disposed alongside, but spaced from, the opening disk so as to create a narrow gap therebetween, wherein the gauge wheel comprises at least one opening in the side wall thereof so as to permit soil to pass from the gap located between the opening disk and the gauge wheel to the region outside of the gauge wheel; a scraper disposed in the gap between the opening disk and the gauge wheel and configured to remove soil from at least one of the opening disk and the gauge wheel and direct the removed soil out the at least one opening, and further wherein the scraper comprises a first surface for removing soil from the opening disk, a second surface for removing soil from the gauge wheel, and a curved body for directing the removed soil out the at least one opening in the gauge wheel; at least one wheel liner disposed adjacent to the at least one opening in the gauge wheel, wherein the wheel liner comprises an inner rim surface to facilitate the egress of soil out the at least one opening; at least one soil deflector disposed adjacent to the at least one opening in the gauge wheel, wherein the soil deflector is positioned along a trailing edge of the at least one opening so as to facilitate the egress of soil out the at least one opening; and at least one soil exit chute disposed adjacent to the at least one opening in the gauge wheel, wherein the soil exit chute comprises a floor and a side wall configured to move soil outboard as it emerges from the at least one opening.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Row planter assemblies are designed to plant rows in an agricultural field, with a plurality of parallel rows being planted with each pass of the row planter assembly. More particularly, with the row planter assembly, for each row, a unit opens a furrow in the soil, distributes the seed into the furrow, and then closes the furrow by pushing soil back over the seed. The row planter assemblies have a plurality of the aforementioned units, one for each row being planted. Each unit has four main components: (i) a pair of gauge wheels which support the unit on the soil being planted and which regulate the depth of the seed furrow; (ii) a pair of opening discs (sometimes referred to as a “double disk opener”) set at an angle to one another for opening the furrow in the soil, with the depth of the opening disks being set relative to the gauge wheels; (iii) a planter for distributing seeds in the open furrow; and (iv) a pair of closing wheels set at an angle to one another for pushing the soil back over the seeds. More particularly, and looking now at FIGS. 1-5 , there is shown a row planter assembly 1 . Planter assembly 1 generally comprises a pair of gauge wheels 5 which support the frame 15 of the row planter assembly 1 on the soil. The two disks 10 of the double disk opener are carried by frame 15 of row planter assembly 1 , with the two disks 10 of the double disk opener being configured in the shape of a V. The depth of the opening disks 10 protrude below the depth of the gauge wheels 5 and, as a result, when the unit is moved across the soil 20 , the opening disks 10 form a furrow 25 in the soil. The gauge wheels 5 are positioned on either side of the opening disks 10 , in close lateral proximity, and by virtue of their adjustable connection to frame 15 , set the depth of the opening disks 10 (i.e., the depth of penetration of the opening disks 10 into the soil 20 ). A planter 30 (e.g., a seed tube) is spaced just back from the opening disks 10 of the double disk opener and serves to deposit seeds into the opened furrow 25 . The closing wheels 35 are positioned at the back end of the unit, and comprise a pair of angled wheels which close the soil 20 back over the deposited seeds. As noted above, in order to properly set the depth of the opening disks 10 (i.e., the depth of penetration of the opening disks 10 into the soil 20 ), it is important for the gauge wheels 5 to be set in close lateral proximity to the opening disks 10 . In relatively dry soil conditions, this does not present a significant problem, since the dry soil can move easily through the gap (i.e., the intervening space) between the opening disks 10 and the gauge wheels 5 . However, in wet soil conditions, the soil is “sticky” (in the sense that it tends to bind to itself) and there is a significant problem with soil building up on the outsides of the opening disks 10 and the insides of the gauge wheels 5 . To this end, a scraper 40 is typically provided to scrape dirt off the face of opening disk 10 . However, when the soil is sticky, soil scraped off the face of opening disk 10 still builds up between the opening disk 10 and the inside of the gauge wheel 5 . Thus, the gap between the opening disks 10 and the gauge wheels 5 can become plugged with mud, which prevents the opening disks 10 and gauge wheels 5 from rotating on their axles. When the gauge wheels 5 stop rotating on their axles, the gauge wheels 5 tend to “drag” across the soil, so that the gauge wheels 5 can no longer reliably set the depth of the furrow 25 . Among other things, when the gauge wheels 5 get plugged with soil in the foregoing manner, the gauge wheels tend to skid across the top of the soil, destroying the seed furrow 25 , so that seed is left on top of the ground rather than deposited into a furrow. In this respect it should be appreciated that the depth of the furrow 25 is frequently quite important for proper crop growth. When the gauge wheels 5 stop rotating so that they can no longer accurately set furrow depth, the farmer must interrupt the planting operation, climb down from the tractor, manually remove the mud from the space between the opening disks 10 and the gauge wheels 5 , climb back up onto the tractor and resume planting—until the machinery clogs once again, in which case the planting operation must be halted once more while the machinery is cleaned in the foregoing manner. Planting in wet conditions, using conventional row planter assemblies, is extremely time-consuming and labor intensive. For example, if the operator of the planter assembly is required to stop the machinery approximately every ten minutes and spend approximately five minutes cleaning the gap between the opening disks 10 and the gauge wheels 5 , productivity is reduced by 33%. Furthermore, operator fatigue is significantly increased, due to the additional exertion of climbing down from the tractor, manually cleaning the space between the opening disks 10 and the gauge wheels 5 and climbing back up into the tractor to resume planting. This loss of productivity and increase in operator fatigue are significant problems, particularly in certain climates, and/or for certain crops, one or both of which may have very limited planting periods. Various efforts have been made in an effort to keep the gauge wheel free of soil build-up. Many of these approaches incorporate the use of scrapers for scraping soil build-up off of the opening disks. However, this type of solution is not entirely satisfactory, since in many cases the scrapers merely push the wet soil off of the opening disks and onto the gauge wheel. This problem can be further complicated due to the presence of various attachment arms for holding various parts to the planter chassis.
|
<SOH> SUMMARY OF THE INVENTION <EOH>It is, therefore, one object of the present invention to provide an improved gauge wheel for use with a conventional row planter assembly, wherein the improved gauge wheel facilitates the egress of soil (particularly sticky wet soil) from the gap located between the opening disk and the gauge wheel. Another object of the present invention is to provide an improved row planter assembly which utilizes the aforementioned improved gauge wheels so as to be less susceptible to clogging due to wet soil conditions. These and other objects are addressed by the present invention, which comprises the provision and use of a novel gauge wheel which prevents a buildup of soil in the gap between the opening disk and the gauge wheel. More particularly, the novel gauge wheel comprises at least one opening formed in the face of the gauge wheel which permits soil to exit the gap between the opening disk and the gauge wheel. As a result of this construction, soil does not build up in the gap between the opening disk and the gauge wheel, the gauge wheels continue to rotate freely, and the depth of the opening disks are properly maintained, whereby planting may continue without interruption, even in wet soil conditions. In one preferred form of the present invention, there is provided a row planter assembly comprising: a frame; an opening disk rotatably mounted to the frame; and a gauge wheel rotatably mounted to the frame and disposed alongside, but spaced from, the opening disk so as to create a narrow gap therebetween; wherein the gauge wheel comprises at least one opening in the side wall thereof so as to permit soil to pass from the gap located between the opening disk and the gauge wheel to the region outside of the gauge wheel. In another preferred form of the invention, there is provided a row planter assembly comprising: a frame; an opening disk rotatably mounted to the frame; a gauge wheel rotatably mounted to the frame and disposed alongside, but spaced from, the opening disk so as to create a narrow gap therebetween, wherein the gauge wheel comprises at least one opening in the side wall thereof so as to permit soil to pass from the gap located between the opening disk and the gauge wheel to the region outside of the gauge wheel; a scraper disposed in the gap between the opening disk and the gauge wheel and configured to remove soil from at least one of the opening disk and the gauge wheel and direct the removed soil out the at least one opening, and further wherein the scraper comprises a first surface for removing soil from the opening disk, a second surface for removing soil from the gauge wheel, and a curved body for directing the removed soil out the at least one opening in the gauge wheel; at least one wheel liner disposed adjacent to the at least one opening in the gauge wheel, wherein the wheel liner comprises an inner rim surface to facilitate the egress of soil out the at least one opening; at least one soil deflector disposed adjacent to the at least one opening in the gauge wheel, wherein the soil deflector is positioned along a trailing edge of the at least one opening so as to facilitate the egress of soil out the at least one opening; and at least one soil exit chute disposed adjacent to the at least one opening in the gauge wheel, wherein the soil exit chute comprises a floor and a side wall configured to move soil outboard as it emerges from the at least one opening.
|
REFERENCE TO PENDING PRIOR PATENT APPLICATIONS This patent application claims benefit of: (1) pending prior U.S. Provisional Patent Application Ser. No. 60/800,550, filed May 15, 2006 by Ron Hesla for GAUGE WHEEL FOR USE WITH A CONVENTIONAL ROW PLANTER ASSEMBLY (Attorney's Docket No. HESLA-1 PROV); and (2) pending prior U.S. Provisional Patent Application Ser. No. 60/922,867, filed Apr. 11, 2007 by Ron Hesla for GAUGE WHEEL FOR USE WITH A CONVENTIONAL ROW PLANTER ASSEMBLY (Attorney's Docket No. HESLA-2 PROV). The two above-identified patent applications are hereby incorporated herein by reference. FIELD OF THE INVENTION This invention relates to agricultural machinery in general, and more particularly to a novel gauge wheel for use with a conventional row planter assembly to facilitate planting in adverse conditions. BACKGROUND OF THE INVENTION Row planter assemblies are designed to plant rows in an agricultural field, with a plurality of parallel rows being planted with each pass of the row planter assembly. More particularly, with the row planter assembly, for each row, a unit opens a furrow in the soil, distributes the seed into the furrow, and then closes the furrow by pushing soil back over the seed. The row planter assemblies have a plurality of the aforementioned units, one for each row being planted. Each unit has four main components: (i) a pair of gauge wheels which support the unit on the soil being planted and which regulate the depth of the seed furrow; (ii) a pair of opening discs (sometimes referred to as a “double disk opener”) set at an angle to one another for opening the furrow in the soil, with the depth of the opening disks being set relative to the gauge wheels; (iii) a planter for distributing seeds in the open furrow; and (iv) a pair of closing wheels set at an angle to one another for pushing the soil back over the seeds. More particularly, and looking now at FIGS. 1-5, there is shown a row planter assembly 1. Planter assembly 1 generally comprises a pair of gauge wheels 5 which support the frame 15 of the row planter assembly 1 on the soil. The two disks 10 of the double disk opener are carried by frame 15 of row planter assembly 1, with the two disks 10 of the double disk opener being configured in the shape of a V. The depth of the opening disks 10 protrude below the depth of the gauge wheels 5 and, as a result, when the unit is moved across the soil 20, the opening disks 10 form a furrow 25 in the soil. The gauge wheels 5 are positioned on either side of the opening disks 10, in close lateral proximity, and by virtue of their adjustable connection to frame 15, set the depth of the opening disks 10 (i.e., the depth of penetration of the opening disks 10 into the soil 20). A planter 30 (e.g., a seed tube) is spaced just back from the opening disks 10 of the double disk opener and serves to deposit seeds into the opened furrow 25. The closing wheels 35 are positioned at the back end of the unit, and comprise a pair of angled wheels which close the soil 20 back over the deposited seeds. As noted above, in order to properly set the depth of the opening disks 10 (i.e., the depth of penetration of the opening disks 10 into the soil 20), it is important for the gauge wheels 5 to be set in close lateral proximity to the opening disks 10. In relatively dry soil conditions, this does not present a significant problem, since the dry soil can move easily through the gap (i.e., the intervening space) between the opening disks 10 and the gauge wheels 5. However, in wet soil conditions, the soil is “sticky” (in the sense that it tends to bind to itself) and there is a significant problem with soil building up on the outsides of the opening disks 10 and the insides of the gauge wheels 5. To this end, a scraper 40 is typically provided to scrape dirt off the face of opening disk 10. However, when the soil is sticky, soil scraped off the face of opening disk 10 still builds up between the opening disk 10 and the inside of the gauge wheel 5. Thus, the gap between the opening disks 10 and the gauge wheels 5 can become plugged with mud, which prevents the opening disks 10 and gauge wheels 5 from rotating on their axles. When the gauge wheels 5 stop rotating on their axles, the gauge wheels 5 tend to “drag” across the soil, so that the gauge wheels 5 can no longer reliably set the depth of the furrow 25. Among other things, when the gauge wheels 5 get plugged with soil in the foregoing manner, the gauge wheels tend to skid across the top of the soil, destroying the seed furrow 25, so that seed is left on top of the ground rather than deposited into a furrow. In this respect it should be appreciated that the depth of the furrow 25 is frequently quite important for proper crop growth. When the gauge wheels 5 stop rotating so that they can no longer accurately set furrow depth, the farmer must interrupt the planting operation, climb down from the tractor, manually remove the mud from the space between the opening disks 10 and the gauge wheels 5, climb back up onto the tractor and resume planting—until the machinery clogs once again, in which case the planting operation must be halted once more while the machinery is cleaned in the foregoing manner. Planting in wet conditions, using conventional row planter assemblies, is extremely time-consuming and labor intensive. For example, if the operator of the planter assembly is required to stop the machinery approximately every ten minutes and spend approximately five minutes cleaning the gap between the opening disks 10 and the gauge wheels 5, productivity is reduced by 33%. Furthermore, operator fatigue is significantly increased, due to the additional exertion of climbing down from the tractor, manually cleaning the space between the opening disks 10 and the gauge wheels 5 and climbing back up into the tractor to resume planting. This loss of productivity and increase in operator fatigue are significant problems, particularly in certain climates, and/or for certain crops, one or both of which may have very limited planting periods. Various efforts have been made in an effort to keep the gauge wheel free of soil build-up. Many of these approaches incorporate the use of scrapers for scraping soil build-up off of the opening disks. However, this type of solution is not entirely satisfactory, since in many cases the scrapers merely push the wet soil off of the opening disks and onto the gauge wheel. This problem can be further complicated due to the presence of various attachment arms for holding various parts to the planter chassis. SUMMARY OF THE INVENTION It is, therefore, one object of the present invention to provide an improved gauge wheel for use with a conventional row planter assembly, wherein the improved gauge wheel facilitates the egress of soil (particularly sticky wet soil) from the gap located between the opening disk and the gauge wheel. Another object of the present invention is to provide an improved row planter assembly which utilizes the aforementioned improved gauge wheels so as to be less susceptible to clogging due to wet soil conditions. These and other objects are addressed by the present invention, which comprises the provision and use of a novel gauge wheel which prevents a buildup of soil in the gap between the opening disk and the gauge wheel. More particularly, the novel gauge wheel comprises at least one opening formed in the face of the gauge wheel which permits soil to exit the gap between the opening disk and the gauge wheel. As a result of this construction, soil does not build up in the gap between the opening disk and the gauge wheel, the gauge wheels continue to rotate freely, and the depth of the opening disks are properly maintained, whereby planting may continue without interruption, even in wet soil conditions. In one preferred form of the present invention, there is provided a row planter assembly comprising: a frame; an opening disk rotatably mounted to the frame; and a gauge wheel rotatably mounted to the frame and disposed alongside, but spaced from, the opening disk so as to create a narrow gap therebetween; wherein the gauge wheel comprises at least one opening in the side wall thereof so as to permit soil to pass from the gap located between the opening disk and the gauge wheel to the region outside of the gauge wheel. In another preferred form of the invention, there is provided a row planter assembly comprising: a frame; an opening disk rotatably mounted to the frame; a gauge wheel rotatably mounted to the frame and disposed alongside, but spaced from, the opening disk so as to create a narrow gap therebetween, wherein the gauge wheel comprises at least one opening in the side wall thereof so as to permit soil to pass from the gap located between the opening disk and the gauge wheel to the region outside of the gauge wheel; a scraper disposed in the gap between the opening disk and the gauge wheel and configured to remove soil from at least one of the opening disk and the gauge wheel and direct the removed soil out the at least one opening, and further wherein the scraper comprises a first surface for removing soil from the opening disk, a second surface for removing soil from the gauge wheel, and a curved body for directing the removed soil out the at least one opening in the gauge wheel; at least one wheel liner disposed adjacent to the at least one opening in the gauge wheel, wherein the wheel liner comprises an inner rim surface to facilitate the egress of soil out the at least one opening; at least one soil deflector disposed adjacent to the at least one opening in the gauge wheel, wherein the soil deflector is positioned along a trailing edge of the at least one opening so as to facilitate the egress of soil out the at least one opening; and at least one soil exit chute disposed adjacent to the at least one opening in the gauge wheel, wherein the soil exit chute comprises a floor and a side wall configured to move soil outboard as it emerges from the at least one opening. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which are to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein: FIG. 1 is a rear view showing a prior art row planter assembly; FIG. 2 is a perspective view showing a prior art opening disk, gauge wheel and closing disks of a row planter assembly; FIG. 3 is a front view showing prior art opening disks and gauge wheels of a row planter assembly; FIG. 4 is a top view showing prior art opening disks, scrapers, gauge wheels and closing disks of a row planter assembly; FIG. 5 is a rear view showing prior art opening disks, gauge wheels, seed tube and closing wheels of a row planter assembly; FIG. 6 is an exploded view of a prior art gauge wheel, scraper and opening disks of a row planter assembly, with soil shown adhering to the outside face of the opening disk and the inside face of the gauge wheel; FIG. 7 illustrates prior art opening disks, scrapers and gauge wheels of a row planter assembly, with soil shown lodged in the gap between the opening disk and the gauge wheel; FIG. 8 is a perspective view showing a novel gauge wheel formed in accordance with the present invention, and also showing an opening disk, scraper and closing disks; FIG. 9 is an exploded view showing a novel gauge wheel formed in accordance with the present invention, and also showing an opening disk, scraper and closing disks; FIG. 10 is a perspective view showing an alternative form of a gauge wheel also formed in accordance with the present invention; FIG. 11 is a perspective view showing a novel form of scraper also formed in accordance with the present invention; FIG. 12 is a front view showing the scraper of FIG. 11 removing soil from the outside face of the opening disk; FIG. 13 is a perspective view showing soil exiting an opening in a gauge wheel formed in accordance with the present invention; FIG. 14 is a side view showing an alternative approach for mounting the scraper adjacent the opening disk; FIG. 15 is a side view showing one way of effecting the construction shown in FIG. 14; FIG. 16 is a side view showing another way of effecting the construction shown in FIG. 14; FIG. 17 is a side view showing another form of scraper, with another mounting arrangement; FIG. 18 is a side view showing another form of scraper, with another mounting arrangement; FIG. 19 is a side view showing another form of scraper, with another mounting arrangement; FIG. 20 is a perspective view showing further details of the construction shown in FIG. 19; FIG. 21 is a perspective view showing a liner formed in accordance with the present invention; and FIG. 22 is a side view in section taken along line 22-22 of FIG. 21; FIG. 23 is a perspective view showing a deflector formed in accordance with the present invention; and FIG. 24 is a perspective view showing another form of liner formed in accordance with the present invention. DETAILED DESCRIPTION OF THE PRESENT INVENTION Looking first at FIGS. 8 and 9, the present invention generally comprises the provision and use of a novel gauge wheel 105 which prevents a buildup of soil in the gap between the opening disk 10 and the gauge wheel. More particularly, the novel gauge wheel 105 comprises at least one opening 107 formed in the face of the gauge wheel which permits soil to exit the gap between the opening disk 10 and the gauge wheel 105. As a result of this construction, soil does not build up in the gap between the opening disk 10 and the gauge wheel 105, the gauge wheels 105 continue to rotate freely, and the depth of the opening disks 10 are properly maintained, whereby planting may continue without interruption, even in wet soil conditions. In one preferred construction, and still looking now at FIGS. 8 and 9, gauge wheel 105 comprises a pair of diametrically-opposed openings 107, with the openings extending along a substantial portion (e.g., greater than about 30%) of the radius of the gauge wheel. And in a preferred construction, each of the openings 107 extends along a substantial arc (e.g., greater than about 50 degrees) of the circumference of the gauge wheel. Of course, it will be appreciated that the number, size and disposition of the openings 107 may vary. In general, openings 107 are sufficient in number, size and disposition to permit soil to exit the gap located between the opening disk 10 and the gauge wheel 105, so as to keep soil from building up in this region and causing gauge wheel 105 to bind. However, it will also be appreciated that sufficient material must be maintained within the face of gauge wheel 105 so as to ensure sufficient wheel integrity to support the weight of the row planter assembly. In addition to the foregoing, the portions of gauge wheel 105 forming the perimeters of the opening 107 may have various configurations, e.g., the surface edges of the openings may be tapered to facilitate egress of soil through the openings, the corners of openings 107 may be radiused, etc. Furthermore, it will be appreciated that gauge wheel 105 may be formed out of any suitable material or materials, e.g., the entire gauge wheel 105 may be formed out of a suitable metal, a suitable plastic, etc.; or the gauge wheel 105 may be formed out of two or more materials, e.g., a metal inner rim and a plastic outer rim, etc. Preferably, a scraper 40 is still used in conjunction with the novel gauge wheel 105. In this situation, the scraper 40 may actually assist, or may be modified to further assist, in directing the loosened soil through the at least one opening 107 in the face of the gauge wheel 105 as the gauge wheel turns. It will be appreciated that numerous benefits are obtained by using the novel gauge wheel design of the present invention. First and foremost, the one or more openings 107 formed in gauge wheel 105 facilitate egress of soil from the gap between the opening disks 10 and the gauge wheels 105. As a result, productivity is increased by allowing more time to be spent planting and less time unplugging clogged planter row units. This in turn permits the farmer to plant more acres in less time, with less fatigue, thereby increasing planting efficiency, particularly in wet soil conditions. In addition to the foregoing, the one or more openings 107 in gauge wheel 105: (i) provide an easy way to examine the row planter assembly's opening disks (particularly their hubs and bearings), scrapers, seed deployment tubes, etc.; (ii) provide a visual cue of gauge wheel rotation; (iii) reduce the total amount of material used to produce the gauge wheel; and (iv) provide increased tolerance for the gap between the opening disks and the gauge wheels, thereby minimizing the time spent to adjust gauge wheel position. Significantly, the present invention may be retroactively installed on existing row planter assemblies as well as used in new row planter assemblies. And the present invention may be used on other farm equipment such as planting drills, etc. And the present invention may be used with virtually any type of seed planting. Novel Scraper The prior art scraper 40 shown in FIG. 6 essentially comprises a wheel which contacts the face of opening disk 10. While prior art scraper 40 works well with the novel gauge wheel 105, with the loosened soil being free to exit the gap located between opening disk 10 and gauge wheel 105 via openings 107, the present invention performs better with the provision of a novel scraper 140. Thus, for example, and looking now at FIGS. 8-13, there is shown the novel scraper 140. Novel scraper 140 serves to remove accumulated soil from the face of opening disk 10 and/or the rim of gauge wheel 105 and direct that loosened soil out of openings 107 of the gauge wheel 105. To this end, novel scraper 140 comprises (i) a flat leading edge 145 for engaging the side wall of the opening disk 10 and freeing the built-up soil from the opening disk, and (ii) a curved body 150 for channeling the scraped-off soil toward the openings 107 in gauge wheel 105, so as to facilitate egress of soil from the space between the opening disk and gauge wheel. Curved body 150 also includes a trailing edge 151 for removing any accumulated soil from the rim of gauge wheel 105 and channel that loosened soil out openings 107. Thus, it will be seen that novel scraper 140 provides one edge 145 for removing accumulated soil from opening disk 10, another edge 151 for removing accumulated soil from gauge wheel 105, and a curved body 150 located between edges 145 and 151 for guiding loosened soil out openings 107. Universal Scraper Arm In the construction shown in FIGS. 8-13, scraper 140 is shown mounted to the chassis 15 of the row planter assembly. This is analogous to the manner in which the prior art scraper 40 is mounted to the chassis 15 of the row planter assembly. In an alternative form of the present invention, scraper 140 is supported adjacent to the opening disc 10 using a universal scraper arm. This universal scraper arm permits the scraper 140 to be properly positioned when using any of the commercially-available opening disks. This universal scraper arm may be mounted to the axle of opening disk 10, or the universal scraper arm may be mounted to the axle of gauge wheel 105. Thus, for example, and looking now at FIGS. 14-16, it will be seen that scraper 140 may be mounted to the axle of the opening disk 10 via universal scraper arm 160. Alternatively, and looking now at FIGS. 17-20, scraper 140 may be mounted to the axle of gauge wheel 105 via universal scraper arm 165. Wheel Liner In an alternate form of the present invention, and looking now at FIGS. 21 and 22, the gauge wheel 105 can be formed with a wheel liner 170. The wheel liner 170 is formed so as to generally follow the shape of the gauge wheel rim at its base, forming an inner rim. The wheel liner 170 is formed so that its inner rim surface 173 gradually slopes downward and outward from the opening disk, towards the exit openings 107 formed in the gauge wheel rim. This sloping of the inner rim surface 173 serves to facilitate egress of soil from the space between the opening disk and gauge wheel. In other words, the varying slope along the inner rim surface 173 is formed so as to create a higher bevel at the inner rim surface furthest from the openings in the gauge wheel, and a lower bevel at the inner rim surface adjacent to the openings in the gauge wheel, whereby to help channel loosened soil out openings 107. Furthermore, the body of wheel liner 170 also acts as a block to prevent the build-up of soil adjacent to openings 107. In one preferred form of the invention, wheel liner 170 is formed so that its inner rim surface 173 is set at an angle of approximately 70 degrees or less to the plane of gauge wheel 105. The wheel liner 170 may be formed with tabs positioned so as to align with existing bolts on the gauge wheel, whereby to facilitate affixing the wheel liner to the gauge wheel. Alternatively, the wheel liner may be provided with a face plate. The face plate is formed with a perimeter slope molding that matches the rim face, thus covering the inner rim face and aligning with all holes formed in the rim face. The face plate includes openings which would align with the soil egress openings of the gauge wheel. Soil Deflector In another preferred form of the present invention, and looking now at FIG. 23, when the wheel liner or face plate is used, a soil deflector 175 may also be provided. The soil deflector 175 is positioned along the inner rim of the gauge wheel, along the vertical trailing edge of the opening in the gauge wheel. The soil deflector 175 serves as an additional means to facilitate egress of soil from the space between the opening disk and gauge wheel. Additionally, the soil deflector 175 will serve to prevent wet soil from sticking to the flat edges of the openings in the gauge wheel. The soil deflector 175 is positioned at an angle of deflection toward the gauge wheel opening 107, and may be formed out of a non-stick material. The soil deflector is attached using an adjacent existing bolt on the gauge wheel. Soil Exit Chute In yet another preferred construction, and looking now at FIG. 24, there is shown a soil exit chute 180 which is positioned adjacent to openings 107, whereby to facilitate egress of soil from the gap located between opening disk 10 and gauge wheel 105. More particularly, FIG. 24 shows how wet soil removed from the opening disk 10 and/or gauge wheel 105 by a scraper (e.g., scraper 140) tends to roll along the perimeter of the gauge wheel rim and, as additional soil is scraped from the opening disk and/or gauge wheel, the newly scraped soil also falls to the perimeter of the gauge wheel rim, sticking to the previously scraped soil. In other words, these soil scrapings have a tendency to stick to each other as well as to the rim of the gauge wheel (and opening disk), effectively forming soil “balls”. Accordingly, the soil exit chute 180 takes advantage of this particle attraction, by providing a soil egress for guiding the soil balls out openings 107. In one preferred form of the invention, soil exit chute 180 comprises a floor 185 and a side wall 187, where floor 185 and side wall 187 are configured to move the soil balls outboard as they emerge from openings 107. The soil exit chute 180 may be manufactured out of a non-stick plastic, or a coated metal, or a combination of the two. Modifications While the present invention has been described in terms of certain exemplary preferred embodiments, it will be readily understood and appreciated by those skilled in the art that it is not so limited, and that many additions, deletions and modifications may be made to the preferred embodiments discussed herein without departing from the scope of the invention.
|
A
|
A01
|
A01C
|
5
|
06
|
|||
11722829
|
US20070285948A1-20071213
|
Backlight Unit, And Display Device Including The Same
|
ACCEPTED
|
20071128
|
20071213
|
[]
|
F21V2100
|
["F21V2100"]
|
7927004
|
20070626
|
20110419
|
362
|
633000
|
79856.0
|
BANNAN
|
JULIE
|
[{"inventor_name_last": "Murakami", "inventor_name_first": "Yoshihiro", "inventor_city": "Mie", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Ogura", "inventor_name_first": "Takeshi", "inventor_city": "Mie", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Nakamichi", "inventor_name_first": "Kazuki", "inventor_city": "Mie", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Hara", "inventor_name_first": "Takafumi", "inventor_city": "Kyoto", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Ohnishi", "inventor_name_first": "Takuya", "inventor_city": "Mie", "inventor_state": "", "inventor_country": "JP"}]
|
A backlight unit is capable of being designed in consideration of both thermal expansion of optical sheets and positioning accuracy of the optical sheets on a backlight chassis. The backlight unit is arranged behind a display panel a and includes a backlight chassis arranged to house a lamp, which includes a support surface arranged to support optical sheets, and a frame arranged to hold the optical sheets with the support surface of the backlight chassis, the optical sheets being interposed between the frame and the support surface, wherein the backlight chassis has, on its support surface, a positioning piece arranged to position the optical sheets at a predetermined position with respect to the support surface, and a position of the positioning piece corresponds to an approximate center of a longer edge of the optical sheets.
|
1-6. (canceled) 7. A backlight unit comprising: a backlight chassis arranged to house a lamp, which includes a support surface arranged to support optical sheets; and a frame arranged to hold the optical sheets with the support surface of the backlight chassis, the optical sheets being interposed between the frame and the support surface; wherein the backlight chassis has, on its support surface, a positioning piece arranged to position the optical sheets at a predetermined position with respect to the support surface, and a position of the positioning piece corresponds to an approximate center of a longer edge of the optical sheets. 8. The backlight unit according to claim 7, wherein the positioning piece has a convex portion which fits into a concave portion including a notch at the approximate center of the longer edge of the optical sheets. 9. The backlight unit according to claim 7, wherein the positioning piece has a concave portion into which a convex portion including a projection at the approximate center of the longer edge of the optical sheets fits. 10. The backlight unit according to claim 7, wherein the backlight chassis is made from a white color synthetic resin, and defines a reflection surface to reflect light emitted from the lamp and let the light enter the display panel. 11. A display device comprising the backlight unit according to claim 7. 12. A backlight unit comprising: a backlight chassis arranged to house a lamp, which includes a support surface arranged to support optical sheets; and a frame arranged to hold the optical sheets with the support surface of the backlight chassis, the optical sheets being interposed between the frame and the support surface; wherein the backlight chassis has contact portions which include a projection on the support surface, the frame has contact portions which include a projection on its interposition surface, and by the contact portions, the backlight chassis and the frame come into partial contact with outside surfaces of the optical sheets. 13. The backlight unit according to claim 12, wherein the backlight chassis is made from a white color synthetic resin, and defines a reflection surface to reflect light emitted from the lamp and let the light enter the display panel. 14. A display device comprising the backlight unit according to claim 12.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a backlight unit for housing a lamp that is a light source of a display device with a backlight, and specifically relates to a backlight unit preferably used in a liquid crystal display device including a translucent liquid crystal display panel. 2. Description of the Related Art A liquid crystal display device including a translucent liquid crystal display panel and the like, which are cited as an example of a flat-screen display device, generally have a backlight unit arranged behind the liquid crystal display panel. The backlight unit is a device including a tubular lamp such as a cold cathode tube as a light source, which controls the properties of light emitted from the tubular lamp and projects the light toward a rear side of the display panel. The projected light passes through the display panel, making an image displayed visible on a front side of the display panel. FIG. 5 is an exploded perspective view schematically illustrating relevant parts of a structure of a generally conventional liquid crystal display device. A liquid crystal display device 30 includes a bezel 31 , a display panel 32 and a backlight unit 33 . The bezel 31 is a member that defines a frame of the display panel 32 , and the display panel 32 is made by bonding two panels of glass so as to seal in a liquid crystal therebetween. The backlight unit 33 includes a frame 34 , optical sheets 35 , tubular lamps 36 , a reflector 37 and a backlight chassis 38 . The frame 34 is shaped like a picture frame and secures the optical sheets 35 to the backlight chassis 38 . The optical sheets 35 are provided for controlling the properties of light which is emitted from the tubular lamps 36 and enters the display panel 32 . In this case, the tubular lamps 36 are U-shaped, and left-side ends thereof are inserted into electrode part holders 41 so as to be secured to the backlight chassis 38 at the left-end positions, as shown in a plan view of FIG. 6 . The reflector 37 is laid under the tubular lamps 36 , for reflecting the light emitted from the tubular lamps 36 toward the display panel 32 . In order to improve reflectivity, projections 37 a having a crest shape are provided on the reflector 37 so as to be located respectively between tube sections 36 a of the tubular lamps 36 . The backlight chassis 38 , substantially in the shape of a box, has a lamp housing portion 38 a including a bottom portion 38 b and side-wall portions 38 c and 38 d , and support surfaces 38 e and 38 f extending outward respectively from upper edges of the side-wall portions 38 c and 38 d . In the backlight chassis 38 , the bottom portion 38 b and the longer side-wall portions 38 c are formed of a member 39 which is prepared by subjecting a metal plate material to plate metal processing, and the shorter side-wall portions 38 d are formed of a member 40 which is molded of resin. The tubular lamp 36 is secured to the lamp housing portion 38 a of the backlight chassis 38 with the use of the above-mentioned electrode part holder 41 , and also with the use of a member 44 which includes lamp clips 42 for holding the tube section 36 a at an approximate midpoint thereof, and a sheet holding pin 43 for preventing the optical sheets 35 which are arranged above from bending downward to preclude luminance irregularity, as illustrated. The member 44 including the lamp clips 42 and the sheet holding pin 43 is secured to the backlight chassis 38 by inserting and engaging protrusions 44 a , which are provided beneath the member 44 , into and with engaging holes 45 which are punched so as to be formed both in the reflector 37 and the bottom portion 38 b , as shown in a detailed drawing in a circle in FIG. 5 . The above-mentioned frame 34 is secured to the support surfaces 38 e and 38 f of the backlight chassis 38 while interposing the optical sheets 35 and the reflector 37 therebetween. In this case, as shown in FIG. 6 , protrusion portions 38 g having a square shape are formed at the four corners of the support surfaces 38 e and 38 f , and concave portions 35 a are formed as a notch at the four corners of the optical sheets 35 . By fitting the protrusion portions 38 g into the concave portions 35 a , the optical sheets 35 are positioned on the support surfaces 38 e and 38 f. Incidentally, as a prior art literature relating to the present invention, Japanese Patent Application Unexamined Publication No. Hei 11-306835 is cited. In the above-described backlight unit 33 , a thermal factor of the tubular lamp 36 that is the light source contributes to thermal expansion or thermal contraction of structural components thereof, and coefficients of thermal expansion and thermal contraction vary among the structural components. Therefore, friction develops at the time of thermal expansion or thermal contraction especially between the optical sheets 35 , and the support surfaces 38 e and 38 f of the backlight chassis 38 and an interposition surface 34 a of the frame 34 interposing the optical sheets 35 therebetween, which causes a problem of making a creaking sound. In addition, as shown in FIG. 6 , in a case where a gap H between the protrusion portion 38 g of the backlight chassis 38 and the concave portion 35 a of the optical sheets 35 which are used for positioning is set as clearance in consideration of a thermal expansion increment of the optical sheets 35 in use, the gap is too large at ambient temperatures during assembly of the backlight unit 33 , so that positioning accuracy is not achieved. In contrast, in a case where the gap H is set in consideration of the positioning accuracy and without consideration of the gap H as clearance of the thermal expansion increment, the optical sheets 35 bend deeply because of no clearance, causing a creaking sound as described above or developing luminance irregularity.
|
<SOH> SUMMARY OF THE INVENTION <EOH>In order to overcome the problems described above, preferred embodiments of the present invention provide a backlight unit that is capable of being designed in consideration of both thermal expansion of optical sheets and positioning accuracy of the optical sheets on a backlight chassis, and also provide a display device including such a backlight unit. According to a preferred embodiment of the present invention, a backlight unit arranged behind a display panel includes a backlight chassis for housing a lamp, which includes a support surface arranged to support optical sheets, and a frame arranged to hold the optical sheets with the support surface of the backlight chassis, the optical sheets being interposed between the frame and the support surface, wherein the backlight chassis has, on its support surface, a positioning piece arranged to position the optical sheets at a predetermined position with respect to the support surface, and a position of the positioning piece corresponds to an approximate center of a longer edge of the optical sheets. In this case, it is preferable that the positioning piece has a convex portion which fits into a concave portion formed as a notch at the approximate center of the longer edge of the optical sheets, or the positioning piece has a concave portion into which a convex portion formed as a projection at the approximate center of the longer edge of the optical sheets fits. In addition, according to another preferred embodiment of the present invention, a backlight unit arranged behind a display panel includes a backlight chassis arranged to house a lamp, which includes a support surface arranged to support optical sheets, and a frame arranged to hold the optical sheets with the support surface of the backlight chassis, the optical sheets being interposed between the frame and the support surface, wherein the backlight chassis has contact portions which are formed as a projection on the support surface, the frame has contact portions which are formed as a projection on its interposition surface, and by the contact portions, the backlight chassis and the frame come into partial contact with outside surfaces of the optical sheets. Further, it is preferable that the backlight chassis is made from a white color synthetic resin, and functions as a reflection surface to reflect light emitted from the lamp and let the light enter the display panel. It is preferable that a display device includes the backlight unit. According to the backlight unit having the above-described configurations, by using the unique configuration in which the backlight chassis has on its support surface the positioning piece arranged to position the optical sheets at the predetermined position with respect to the support surface and the position of the positioning piece corresponds to the approximate center of the longer edge of the optical sheets since a change in length of the optical sheets caused by thermal expansion is more significant in a longitudinal direction thereof, the backlight unit is capable of being designed in consideration of both thermal expansion of the optical sheets and positioning accuracy of the optical sheets on the backlight chassis. In this case, by using the unique configuration in which the positioning piece has the convex portion which fits into the concave portion formed as a notch at the approximate center of the longer edge of the optical sheets, or the configuration in which the positioning piece has the concave portion into which the convex portion formed as a projection at the approximate center of the longer edge of the optical sheets fits, a structure for positioning is simplified. In addition, by using the unique configuration in which the backlight chassis has the contact portions which are formed as a projection on the support surface and the frame has the contact portions which are formed as a projection on its interposition surface and by the contact portions the backlight chassis and the frame come into partial contact with the outside surfaces of the optical sheets, a contact area with the optical sheets can be decreased to prevent occurrence of a creaking sound due to friction. Further, by using the configuration in which the backlight chassis is made from the white color synthetic resin and functions as the reflection surface to reflect the light emitted from the lamp and let the light enter the display panel, the need for separately providing a reflector as in the Related Art and the need for interposing it are eliminated, so that the contact portions which come into partial contact with the outside surfaces of the optical sheets are easily provided on the support surface of the backlight chassis. By preparing a display device incorporating the backlight unit having the above-described configurations, the occurrence of a creaking sound during use can be prevented. Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the attached drawings.
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit for housing a lamp that is a light source of a display device with a backlight, and specifically relates to a backlight unit preferably used in a liquid crystal display device including a translucent liquid crystal display panel. 2. Description of the Related Art A liquid crystal display device including a translucent liquid crystal display panel and the like, which are cited as an example of a flat-screen display device, generally have a backlight unit arranged behind the liquid crystal display panel. The backlight unit is a device including a tubular lamp such as a cold cathode tube as a light source, which controls the properties of light emitted from the tubular lamp and projects the light toward a rear side of the display panel. The projected light passes through the display panel, making an image displayed visible on a front side of the display panel. FIG. 5 is an exploded perspective view schematically illustrating relevant parts of a structure of a generally conventional liquid crystal display device. A liquid crystal display device 30 includes a bezel 31, a display panel 32 and a backlight unit 33. The bezel 31 is a member that defines a frame of the display panel 32, and the display panel 32 is made by bonding two panels of glass so as to seal in a liquid crystal therebetween. The backlight unit 33 includes a frame 34, optical sheets 35, tubular lamps 36, a reflector 37 and a backlight chassis 38. The frame 34 is shaped like a picture frame and secures the optical sheets 35 to the backlight chassis 38. The optical sheets 35 are provided for controlling the properties of light which is emitted from the tubular lamps 36 and enters the display panel 32. In this case, the tubular lamps 36 are U-shaped, and left-side ends thereof are inserted into electrode part holders 41 so as to be secured to the backlight chassis 38 at the left-end positions, as shown in a plan view of FIG. 6. The reflector 37 is laid under the tubular lamps 36, for reflecting the light emitted from the tubular lamps 36 toward the display panel 32. In order to improve reflectivity, projections 37a having a crest shape are provided on the reflector 37 so as to be located respectively between tube sections 36a of the tubular lamps 36. The backlight chassis 38, substantially in the shape of a box, has a lamp housing portion 38a including a bottom portion 38b and side-wall portions 38c and 38d, and support surfaces 38e and 38f extending outward respectively from upper edges of the side-wall portions 38c and 38d. In the backlight chassis 38, the bottom portion 38b and the longer side-wall portions 38c are formed of a member 39 which is prepared by subjecting a metal plate material to plate metal processing, and the shorter side-wall portions 38d are formed of a member 40 which is molded of resin. The tubular lamp 36 is secured to the lamp housing portion 38a of the backlight chassis 38 with the use of the above-mentioned electrode part holder 41, and also with the use of a member 44 which includes lamp clips 42 for holding the tube section 36a at an approximate midpoint thereof, and a sheet holding pin 43 for preventing the optical sheets 35 which are arranged above from bending downward to preclude luminance irregularity, as illustrated. The member 44 including the lamp clips 42 and the sheet holding pin 43 is secured to the backlight chassis 38 by inserting and engaging protrusions 44a, which are provided beneath the member 44, into and with engaging holes 45 which are punched so as to be formed both in the reflector 37 and the bottom portion 38b, as shown in a detailed drawing in a circle in FIG. 5. The above-mentioned frame 34 is secured to the support surfaces 38e and 38f of the backlight chassis 38 while interposing the optical sheets 35 and the reflector 37 therebetween. In this case, as shown in FIG. 6, protrusion portions 38g having a square shape are formed at the four corners of the support surfaces 38e and 38f, and concave portions 35a are formed as a notch at the four corners of the optical sheets 35. By fitting the protrusion portions 38g into the concave portions 35a, the optical sheets 35 are positioned on the support surfaces 38e and 38f. Incidentally, as a prior art literature relating to the present invention, Japanese Patent Application Unexamined Publication No. Hei 11-306835 is cited. In the above-described backlight unit 33, a thermal factor of the tubular lamp 36 that is the light source contributes to thermal expansion or thermal contraction of structural components thereof, and coefficients of thermal expansion and thermal contraction vary among the structural components. Therefore, friction develops at the time of thermal expansion or thermal contraction especially between the optical sheets 35, and the support surfaces 38e and 38f of the backlight chassis 38 and an interposition surface 34a of the frame 34 interposing the optical sheets 35 therebetween, which causes a problem of making a creaking sound. In addition, as shown in FIG. 6, in a case where a gap H between the protrusion portion 38g of the backlight chassis 38 and the concave portion 35a of the optical sheets 35 which are used for positioning is set as clearance in consideration of a thermal expansion increment of the optical sheets 35 in use, the gap is too large at ambient temperatures during assembly of the backlight unit 33, so that positioning accuracy is not achieved. In contrast, in a case where the gap H is set in consideration of the positioning accuracy and without consideration of the gap H as clearance of the thermal expansion increment, the optical sheets 35 bend deeply because of no clearance, causing a creaking sound as described above or developing luminance irregularity. SUMMARY OF THE INVENTION In order to overcome the problems described above, preferred embodiments of the present invention provide a backlight unit that is capable of being designed in consideration of both thermal expansion of optical sheets and positioning accuracy of the optical sheets on a backlight chassis, and also provide a display device including such a backlight unit. According to a preferred embodiment of the present invention, a backlight unit arranged behind a display panel includes a backlight chassis for housing a lamp, which includes a support surface arranged to support optical sheets, and a frame arranged to hold the optical sheets with the support surface of the backlight chassis, the optical sheets being interposed between the frame and the support surface, wherein the backlight chassis has, on its support surface, a positioning piece arranged to position the optical sheets at a predetermined position with respect to the support surface, and a position of the positioning piece corresponds to an approximate center of a longer edge of the optical sheets. In this case, it is preferable that the positioning piece has a convex portion which fits into a concave portion formed as a notch at the approximate center of the longer edge of the optical sheets, or the positioning piece has a concave portion into which a convex portion formed as a projection at the approximate center of the longer edge of the optical sheets fits. In addition, according to another preferred embodiment of the present invention, a backlight unit arranged behind a display panel includes a backlight chassis arranged to house a lamp, which includes a support surface arranged to support optical sheets, and a frame arranged to hold the optical sheets with the support surface of the backlight chassis, the optical sheets being interposed between the frame and the support surface, wherein the backlight chassis has contact portions which are formed as a projection on the support surface, the frame has contact portions which are formed as a projection on its interposition surface, and by the contact portions, the backlight chassis and the frame come into partial contact with outside surfaces of the optical sheets. Further, it is preferable that the backlight chassis is made from a white color synthetic resin, and functions as a reflection surface to reflect light emitted from the lamp and let the light enter the display panel. It is preferable that a display device includes the backlight unit. According to the backlight unit having the above-described configurations, by using the unique configuration in which the backlight chassis has on its support surface the positioning piece arranged to position the optical sheets at the predetermined position with respect to the support surface and the position of the positioning piece corresponds to the approximate center of the longer edge of the optical sheets since a change in length of the optical sheets caused by thermal expansion is more significant in a longitudinal direction thereof, the backlight unit is capable of being designed in consideration of both thermal expansion of the optical sheets and positioning accuracy of the optical sheets on the backlight chassis. In this case, by using the unique configuration in which the positioning piece has the convex portion which fits into the concave portion formed as a notch at the approximate center of the longer edge of the optical sheets, or the configuration in which the positioning piece has the concave portion into which the convex portion formed as a projection at the approximate center of the longer edge of the optical sheets fits, a structure for positioning is simplified. In addition, by using the unique configuration in which the backlight chassis has the contact portions which are formed as a projection on the support surface and the frame has the contact portions which are formed as a projection on its interposition surface and by the contact portions the backlight chassis and the frame come into partial contact with the outside surfaces of the optical sheets, a contact area with the optical sheets can be decreased to prevent occurrence of a creaking sound due to friction. Further, by using the configuration in which the backlight chassis is made from the white color synthetic resin and functions as the reflection surface to reflect the light emitted from the lamp and let the light enter the display panel, the need for separately providing a reflector as in the Related Art and the need for interposing it are eliminated, so that the contact portions which come into partial contact with the outside surfaces of the optical sheets are easily provided on the support surface of the backlight chassis. By preparing a display device incorporating the backlight unit having the above-described configurations, the occurrence of a creaking sound during use can be prevented. Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view schematically illustrating a backlight unit included in a liquid crystal display device according to a preferred embodiment of the present invention. FIG. 2 is a top view showing the backlight unit shown in FIG. 1 in a state where a frame is removed. FIGS. 3A and 3B are views showing examples of configurations in which a positioning piece having a convex portion shown in FIG. 1 is provided separately from a backlight chassis. FIG. 4 is a view showing a modified example of the backlight unit shown in FIG. 1. FIG. 5 is an exploded perspective view schematically illustrating a backlight unit of a conventional liquid crystal display device. FIG. 6 is a top view showing the backlight unit shown in FIG. 5 in a state where a frame is removed. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A detailed description of a display device according to preferred embodiments of the present invention will now be given with reference to the accompanying drawings. FIG. 1 is an exploded perspective view schematically illustrating relevant parts of a structure of a liquid crystal display device according to preferred embodiments of the present invention. FIG. 2 is a top view showing the backlight unit shown in FIG. 1 in a state where a frame is removed. Besides, the exploded perspective view of FIG. 1 is an enlarged view of an upper right portion of the backlight unit of FIG. 2. As shown in FIG. 1, a liquid crystal display device 1 includes a bezel 2, a display panel 3 and a backlight unit 4. The bezel 2 is a member defining a frame of the display panel 3, which protects the display panel 3 and ensures strength of the entire liquid crystal display device 1. The display panel 3 is made by bonding two panels of glass to seal in a liquid crystal therebetween. The backlight unit 4 includes a frame 5, optical sheets 6, tubular lamps 7 and a backlight chassis 8. The frame 5 is preferably shaped like a picture frame and secures the optical sheets 6 to the backlight chassis 8. The optical sheets 6 are made by stacking members in the shape of a plate or sheet such as a diffusion plate, a diffusion sheet, a lens sheet and a polarizing reflection film in order to control the properties of light which is emitted from the tubular lamps 7 and enters the display panel 3. The tubular lamps 7 are preferably substantially U-shaped cold cathode tubes, and left-side ends thereof are inserted into electrode part holders 9 so as to be secured to the backlight chassis 8 at the left-end positions, as shown in FIG. 2. The backlight chassis 8 is shaped like a box preferably made by molding a white color synthetic resin material, which has a lamp housing portion 8a including a bottom portion 8b, longer side-wall portions 8c and shorter side-wall portions 8d, and support surfaces 8e and 8f extending outward respectively from upper edges of the side-wall portions 8c and 8d. Incidentally, behind the backlight chassis 8, an inverter circuit board incorporating an inverter circuit to drive the tubular lamps 7 is installed, which is not illustrated. In addition, a rear surface of the backlight chassis 8 is subjected to light shielding treatment to be made black or the like, so that a leak of the light emitted from the tubular lamps 7 from the rear surface is prevented. The lamp housing portion 8a is preferably made from the synthetic resin material of white color that is a color to reflect light most efficiently, so that a surface of the lamp housing portion 8a is configured as a reflection surface 8g having a function of reflecting the light emitted from the tubular lamps 7 toward the display panel 3. In addition, in order to further improve reflectivity, reflection crests 8h formed as a projection in a crest shape are provided on the reflection surface 8g so as to be located respectively between tube sections 7a of the tubular lamps 7. Likewise, in order to further improve reflectivity, the longer side-wall portions 8c of the lamp housing portion 8a have inclined surfaces 8i. For securing the tubular lamps 7 to the lamp housing portion 8a, the electrode part holders 9 are provided as mentioned as above, and lamp clips 10 for holding the tube sections 7a at an approximate midpoint, in this case, in the vicinities of substantially U-shaped sections 7b, are provided while being molded in one piece with the backlight chassis 8, as illustrated. The tube sections 7a are held by the lamp clips 10 so as to leave a gap that is substantially equal to a thickness of a base 10a of the lamp clip 10 spaced from the reflection surface 8g. In addition, to the center reflection crest 8h, sheet holding pins 11 are provided while being molded in one piece with the backlight chassis 8. The sheet holding pins 11 are used for preventing the optical sheets 6 which are arranged above the sheet holding pins 11 from bending downward to preclude luminance irregularity, and have a length so as to leave a predetermined space between the optical sheets 6 and the reflection surface 8g. In this case, the sheet holding pins 11 are formed in positions corresponding to a center portion 6a of the optical sheets 6. The above-mentioned frame 5 is secured to the support surfaces 8e and 8f of the backlight chassis 8 while interposing the optical sheets 6 therebetween. In this case, a positioning piece 8j having a convex portion is formed as an arc-shaped projection at an approximate center of the longer support surface 8e, and corresponding to the convex portion of the positioning piece 8j, a concave portion 6b is formed as an arc-shaped notch at an approximate center of a longer edge of the optical sheets 6. By fitting the convex portion of the positioning piece 8j into the concave portion 6b, the optical sheets 6 are positioned on the support surfaces 8e and 8f. In addition, on the support surfaces 8e and 8f of the backlight chassis 8, a plurality of contact portions 8k and a plurality of contact portions 8l having the shape of a rib are respectively arranged in longitudinal directions of the support surfaces 8e and 8f. In addition, as shown in FIG. 1, on an interposition surface 5a of the frame 5, a plurality of contact portions 5b and a plurality of contact portions 5c having the shape of a rib are respectively arranged in longitudinal directions of a longer side and a shorter side of the frame 5. According to the backlight unit 4 having the above-described configuration, the optical sheets 6 are positioned on the backlight chassis 8 with respect to an approximately center position of the longer support surface 8e. Since a change in length of the optical sheets 6 caused by thermal expansion is more significant in a longitudinal direction thereof, by performing the positioning with respect to the approximate center position of the longer support surface 8e, the backlight unit 4 is made in consideration of both thermal expansion of the optical sheets 6 and positioning accuracy of the optical sheets 6 on the backlight chassis 8. In addition, the backlight unit 4 is configured such that the support surfaces 8e and 8f of the backlight chassis 8 and the interposition surface 5a of the frame 5 come into partial contact with the optical sheets 6 while interposing the optical sheets 6 there between via the contact portions 8k, 8l, 5b and 5c formed as a projection. Therefore, a contact area with the optical sheets 6 can be decreased, which can prevent occurrence of a creaking sound by friction. Further, since the backlight chassis 8 is preferably made from the white color synthetic resin and configured to function as the reflection surface 8g which reflects the light emitted from the tubular lamps 7 to let it enter the display panel 3, the need for separately providing a reflector as in the Related Art and the need for interposing it are eliminated. Therefore, the contact portions 8k which come into partial contact with the surface of the optical sheets 6 are easily provided on the support surface 8e of the backlight chassis 8, so that a structure thereof can be simplified. Incidentally, the positioning piece 8j may be provided separately from the backlight chassis 8. For example, the positioning piece 8j may be provided by bonding with the use of an adhesive on its undersurface as shown in FIG. 3A, or the positioning piece 8j may be provided by forming an engaging protrusion portion on its undersurface to be inserted into an engaging hole which is formed on the support surface 8e of the backlight chassis 8 as shown in FIG. 3B. Next, a detailed description of a liquid crystal display device according to another preferred embodiment of the present invention will be given with reference to FIG. 4. Incidentally, explanations of the same configurations as those in the above-mentioned preferred embodiment are omitted, and different respects are explained mainly, providing the same reference numerals as those in the above-mentioned preferred embodiment to the same structural components. As illustrated, in this preferred embodiment, a positioning piece 8m having a concave portion is formed as an arc-shaped notch at the approximate center of the longer support surface 8e of the backlight chassis 8, and corresponding to the concave portion of the positioning piece 8m, a convex portion 6c is formed as an arc-shaped projection at the approximate center of the longer edge of the optical sheets 6. By fitting the convex portion 6c into the concave portion of the positioning piece 8m, the optical sheets 6 are positioned on the support surfaces 8e and 8f. In addition, contact portions 8n having a substantially triangular shape are formed at the four corners of the support surfaces 8e and 8f of the backlight chassis 8, and corresponding contact portions having a substantially triangular shape are formed also on the interposition surface 5a of the frame 5, which are not illustrated. According to such a configuration, the optical sheets 6 are positioned on the backlight chassis 8 with respect to the approximately center position of the longer support surface 8e, and a contact area with the optical sheets 6 can be decreased owing to the contact portions 8n. The foregoing description of preferred embodiments and the implementation example of the present invention has been presented for purposes of illustration and description with reference to the drawings. However, it is not intended to limit the present invention to the preferred embodiments, and modifications and variations are possible as long as they do not deviate from the principles of the present invention. For example, for the shape of the contact portions with the optical sheets, a variety of shapes such as a dome shape can be used instead of the above-described rib shape or substantially triangular shape, which is not limited to the above-described preferred embodiments. While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
|
F
|
F21
|
F21V
|
21
|
00
|
|||
11978271
|
US20080065087A1-20080313
|
Methods for treating a fractured and/or diseased and/or weakened bone
|
ACCEPTED
|
20080227
|
20080313
|
[]
|
A61B1758
|
["A61B1758"]
|
8246681
|
20071029
|
20120821
|
623
|
017110
|
96945.0
|
CARTER
|
TARA ROSE
|
[{"inventor_name_last": "Osorio", "inventor_name_first": "Reynaldo", "inventor_city": "Daly City", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Follmer", "inventor_name_first": "Marialulu", "inventor_city": "Santa Clara", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Layne", "inventor_name_first": "Richard", "inventor_city": "Palo Alto", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Boucher", "inventor_name_first": "Ryan", "inventor_city": "San Francisco", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Talmadge", "inventor_name_first": "Karen", "inventor_city": "Palo Alto", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Basista", "inventor_name_first": "Joseph", "inventor_city": "Mountain View", "inventor_state": "CA", "inventor_country": "US"}]
|
Introduction of a bone filler material into at least a portion of the cancellous bone volume pressurizes the bone filler material and compresses the cancellous bone volume within the bone structure.
|
1. A method comprising establishing a percutaneous path into a vertebral body having cortical bone enclosing a cancellous bone volume, forming a cavity in the cancellous bone volume, and compressing at least a portion of the cancellous bone volume by injecting a bone filler material into the cavity. 2. A method according to claim 1, wherein the bone filler material comprises a bone cement. 3. A method according to claim 1 further comprising moving a fractured cortical bone of the vertebral body to a pre-fractured position by injecting additional bone filler material into the cavity. 4. A method according to claim 3, wherein the bone filler material comprises a bone cement. 5. A method according to claim 1 further comprising pushing the bone filler outward against the walls of the cavity to increase the size of the cavity by injecting additional bone filler material into the cavity. 6. A method according to claim 5, wherein the bone filler material comprises a bone cement. 7. A method comprising establishing a percutaneous path into a bone structure having cortical bone enclosing a cancellous bone volume, introducing a bone filler material into at least a portion of the cancellous bone volume, pressurizing the bone filler material within the bone structure by continuing the introduction of the bone filler material into the cancellous bone volume, and compressing the cancellous bone volume within the bone structure by the pressurizing of the bone filler material. 8. A method according to claim 7 wherein the pressurizing of the bone filler material within the bone structure moves fractured cortical bone. 9. A method according to claim 7 wherein the bone structure comprises a vertebral body. 10. A method according to claim 7 wherein the bone filler material comprises a bone cement. 11. A method according to claim 7, wherein the bone filler material comprises at least one of a bone filler, a bone cement, a synthetic bone substitute, a bone biomaterial, a hydroxyapatite material, a bone mineral material, a thixotropic material, a curable biomaterial, allograft tissue, and autograft tissue. 12. A method comprising creating a cavity a vertebral body, introducing a first amount of a bone filler material into the cavity, and introducing a second amount of the bone filler material into the cavity such that the bone filler pushes outward against a wall of the cavity, thereby compressing a cancellous bone in the vertebral body and increasing the size of the cavity. 13. A method according to claim 11 wherein introducing the second amount of the bone filler material moves fractured cortical bone of the vertebral body. 14. A method according to claim 13 further comprising moving the cortical bone until the fractured cortical bone regains a pre-fractured position. 15. A method comprising compressing at least a portion of a cancellous bone volume within a vertebral body by injecting a bone filler material into the cancellous bone volume. 16. A method according to claim 15 further comprising moving fractured cortical bone of the vertebral body by injecting additional bone filler material into the vertebral body. 17. A method according to claim 16 further comprising moving fractured cortical bone to a pre-fractured position. 18. A method according to claim 15 wherein the bone filler comprises a bone cement. 19. A method according to claim 15, wherein the bone filler material comprises at least one of a bone filler, a bone cement, a synthetic bone substitute, a bone biomaterial, a hydroxyapatite material, a bone mineral material, a thixotropic material, a curable biomaterial, allograft tissue, and autograft tissue. 20. A method comprising selecting a vertebral body having an interior volume occupied, at least in part, by cancellous bone, establishing a percutaneous path into the vertebral body, establishing into the cancellous bone through the percutaneous path a flow path having an initial flow path volume, and conveying a bone filling material into the flow path in a volume that exceeds the initial flow path volume resulting in enlargement of the initial flow path volume to compress at least a portion of the cancellous bone volume. 21. A method according to claim 20 wherein the selected vertebral body has at least one cortical plate that is depressed due to fracture, and wherein conveying the bone filling material results in enlargement of the initial flow path volume to move the fractured cortical plate toward a desired pre-fracture anatomic position. 22. A method according to claim 20 wherein the initial volume of the flow path is established by a tool introduced through the percutaneous path. 23. A method according to claim 22 wherein the tool comprises an expandable body. 24. A method according to claim 22 wherein the tool comprises at least one of a mechanical tamp, reamer, or hole puncher. 25. A method according to claim 20 wherein the bone filling material comprises bone cement.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to devices and methods for treating fractured and/or diseased bone. More specifically, the present invention relates to devices and methods for repairing, reinforcing and/or treating fractured and/or diseased bone using various devices, including cavity-forming devices. 2. Description of the Background Normal healthy bone is composed of a framework made of proteins, collagen and calcium salts. Healthy bone is typically strong enough to withstand the various stresses experienced by an individual during his or her normal daily activities, and can normally withstand much greater stresses for varying lengths of time before failing. However, osteoporosis or a host of other diseases, including such diseases as breast cancer, hemangiomas, osteolytic metastases or spinal myeloma lesions, as well as the long term excessive use of alcohol, tobacco and/or various drugs, can affect and significantly weaken healthy bone over time. If unchecked, such factors can degrade bone strength to a point where the bone is especially prone to fracture, collapse and/or is unable to withstand even normal daily stresses. Unfortunately, losses in bone strength are often difficult to discover until bone integrity has already been seriously compromised. For instance, the effects of osteoporosis are often not discovered until after a bone fracture has already occurred, at which time much of the patient's overall bone strength has typically weakened to dangerous levels. Moreover, as most bone development occurs primarily during childhood and early adulthood, long-term losses in bone strength are typically irreversible. In addition, many bone diseases, including osteoporosis, cancer, and other bone-related disorders, are not routinely curable at our current stage of medical development. For many individuals in our aging world population, undiagnosed and/or untreatable bone strength losses have already weakened these individuals' bones to a point that even normal daily activities pose a significant threat of fracture. For example, when the bones of the spine are sufficiently weakened, the compressive forces in the spine can often cause fracture and/or deformation of the vertebral bodies. For sufficiently weakened bone, even normal daily activities like walking down steps or carrying groceries can cause a collapse of one or more spinal bones, much like a piece of chalk collapses under the compressive weight of a human foot. A fracture of the vertebral body in this manner is typically referred to as a vertebral compression fracture. Researchers estimate that at least 25 percent of all women, and a somewhat smaller percentage of men, over the age of 50 will suffer one or more vertebral compression fractures due to osteoporosis alone. In the United States, it is estimated that over 700,000 vertebral compression fractures occur each year, over 200,000 of which require some form of hospitalization. Other commonly occurring fractures resulting from weakened bones can include hip, wrist, knee and ankle fractures, to name a few. Fractures such as vertebral compression fractures often result in episodes of pain that are chronic and intense. Aside from the pain caused by the fracture itself, the involvement of the spinal column can result in pinched and/or damaged nerves, causing paralysis, loss of function, and intense pain which radiates throughout the patient's body. Even where nerves are not affected, however, the intense pain associated with all types of fractures is debilitating, resulting in a great deal of stress, impaired mobility and other long-term consequences. For example, progressive spinal fractures can, over time, cause serious deformation of the spine (“kyphosis”), giving an individual a hunched-back appearance, and can also result in significantly reduced lung capacity and increased mortality. Until recently, treatment options for vertebral compression fractures, as well as other serious fractures and/or losses in bone strength, were extremely limited—mainly pain management with strong oral or intravenous medications, reduced activity, bracing and/or radiation therapy, all with mediocre results. Because patients with these problems are typically older, and often suffer from various other significant health complications, many of these individuals are unable to tolerate invasive surgery. In addition, to curb further loss of bone strength, many patients are given hormones and/or vitamin/mineral supplements—again with mediocre results and often with significant side effects. Over the past decade, a technique called vertebroplasty has been introduced into the United States. Vertebroplasty involves the injection of a flowable reinforcing material, usually polymethylmethacrylate (PMMA—commonly known as bone cement), into a fractured, weakened, or diseased vertebral body. Shortly after injection, the liquid filling material hardens or polymerizes, desirably supporting the vertebral body internally, alleviating pain and preventing further collapse of the injected vertebral body. While vertebroplasty has been shown to reduce some pain associated with vertebral compression fractures, this procedure has certain inherent drawbacks. The most significant danger associated with vertebroplasty is the inability of the practitioner to control the flow of liquid bone cement during injection into a vertebral body. Although the location and flow patterns of the cement can be monitored by CT scanning or x-ray fluoroscopy, once the liquid cement exits the injection needle, it naturally follows the path of least resistance within the bone, which is often through the cracks and/or gaps in the cancellous and/or cortical bone. Moreover, because the cancellous bone resists the injection of the bone cement and small diameter needles are typically used in vertebroplasty procedures, extremely high pressures are required to force the bone cement through the needle and into the vertebral body. Bone cement, which is viscous, is difficult to inject through small diameter needles, and thus many practitioners choose to “thin out” the cement mixture to improve cement injection, which ultimately exacerbates the leakage problems. In a recent study where 37 patients with bone metastases or multiple myeloma were treated with vertebroplasty, 72.5% of the procedures resulted in leakage of the cement outside the vertebral body. Cortet B. et al., Percutaneous Vertebroplasty in Patients With Osteolytic Metastases or Multiple Myeloma (1998). Moreover, where the practitioner attempts to “thin out” the cement by adding additional liquid monomer to the cement mix, the amount of unpolymerized or “free” monomer increases, which can ultimately be toxic to the patient. Another drawback of vertebroplasty is due to the inability to visualize (using CT scanning or x-ray fluoroscopy) the various venous and other soft tissue structures existent within the vertebra. While the position of the needle within the vertebral body is typically visualized, the location of the venous structures within the vertebral body are not. Accordingly, a small diameter vertebroplasty needle can easily be accidentally positioned within a vein in the vertebral body, and liquid cement pumped directly into the venous system, where the cement easily passes out the anterior and/or posterior walls of the vertebrae through the anterior external venous plexus or the basivertebral vein. Another significant drawback inherent in vertebroplasty is the inability of this procedure to restore the vertebral body to a pre-fractured condition prior to the injection of the reinforcing material. Because the bone is fractured and/or deformed, and not repositioned prior to the injection of cement, vertebroplasty essentially “freezes” the bone in its fractured condition. Moreover, it is highly unlikely that a traditional vertebroplasty procedure could be capable of restoring significant pre-fracture anatomy—because bone cement flows towards the path of least resistance, any en-masse movement of the cortical bone would likely create gaps in the interior and/or walls of the vertebral body through which the bone cement would then immediately flow. A more recently developed procedure for treating fractures such as vertebral compression fractures and other bone-related disorders is known as Kyphoplasty™. See, for example, U.S. Pat. Nos. 4,969,888 and 5,108,404. In Kyphoplasty, an expandable body is inserted through a small opening in the fractured or weakened bone, and then expanded within the bone. This procedure compresses the cancellous bone, and desirably moves the fractured bone to its pre-fractured orientation, creating a cavity within the bone that can be filled with a settable material such as cement or any number of synthetic bone substitutes. In effect, the procedure “sets” the bone at or near its pre-fracture position and creates an internal “cast,” protecting the bone from further fracture and/or collapse. This procedure is of course suitable for use in various other bones as well. While Kyphoplasty can restore bones to a pre-fractured condition, and injected bone filler is less likely to leak out of the vertebral body during a Kyphoplasty procedure, Kyphoplasty requires a greater number of surgical tools than a vertebroplasty procedure, at an increased cost. Moreover, Kyphoplasty tools are typically larger in diameter than vertebroplasty tools, and thus require larger incisions and are generally more invasive.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention overcomes many of the problems and disadvantages associated with current strategies and designs in medical procedures to repair, reinforce and/or treat weakened, diseased and/or fractured bone. One aspect of the invention provides a method comprising compressing at least a portion of a cancellous bone volume within a bone structure, e.g., a vertebral body by injecting a bone filler material into the cancellous bone volume. In one embodiment, the method comprises moving fractured cortical bone of the bone structure by injecting bone filler material into the cancellous bone volume. The method includes moving fractured cortical bone to a pre-fractured position. The bone filler material can comprise, e.g., at least one of a bone filler, a bone cement, a synthetic bone substitute, a bone biomaterial, a hydroxyapatite material, a bone mineral material, a thixotropic material, a curable bio-material, allograft tissue, and autograft tissue. Other objects, advantages, and embodiments of the invention are set forth in part in the description which follows, and in part, will be obvious from this description, or may be learned from the practice of the invention.
|
RELATED APPLICATIONS This application is a divisional of co-pending U.S. patent application Ser. No. 11/789,643, filed 25 Apr. 2007, and entitled “Methods for Treating Fractured and/or Diseased and/or Weakened Bone,” which is a divisional of U.S. patent application Ser. No. 10/783,723, filed 20 Feb. 2004, and entitled “Methods and Devices for Treating Fractured and/or Diseased Bone,” which is a divisional of U.S. patent application Ser. No. 09/827,260, filed 5 Apr. 2001 (now U.S. Pat. No. 6,726,691), which claims the benefit of U.S. Provisional Patent Application No. 60/194,685, filed 5 Apr. 2000 (Expired), and which is also a continuation-in-part of co-pending U.S. patent application Ser. No. 10/346,618, filed 17 Jan. 2003, which is a divisional of U.S. patent application Ser. No. 09/597,646, filed 20 Jun. 2000 (now U.S. Pat. No. 6,716,216), which is a continuation-in-part of U.S. patent application Ser. No. 09/134,323, filed 14 Aug. 1998 (now U.S. Pat. No. 6,241,734), each of which is incorporated herein by reference. This application is also a continuation-in-part of co-pending U.S. patent application Ser. No. 10/958,600, filed 5 Oct., 2004, and entitled “Systems and Methods for Treating Fractured or Diseased Bone Using Expandable Bodies,” which is a divisional of U.S. patent application Ser. No. 09/754,451, filed 4 Jan. 2001 (now U.S. Pat. No. 6,899,719), which is a continuation of U.S. patent application Ser. No. 08/871,114, filed 9 Jun. 1997 (now U.S. Pat. No. 6,248,110), which is a continuation-in-part of U.S. patent application Ser. No. 08/659,678, filed 5 Jun. 1996 (now U.S. Pat. No. 5,827,289); which is a continuation-in-part of U.S. patent application Ser. No. 08/485,394, filed 7 Jun. 1995 (Abandoned), which is a continuation-in-part of U.S. patent application Ser. No. 08/188,224, filed 26 Jan. 1994 (Abandoned), each of which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to devices and methods for treating fractured and/or diseased bone. More specifically, the present invention relates to devices and methods for repairing, reinforcing and/or treating fractured and/or diseased bone using various devices, including cavity-forming devices. 2. Description of the Background Normal healthy bone is composed of a framework made of proteins, collagen and calcium salts. Healthy bone is typically strong enough to withstand the various stresses experienced by an individual during his or her normal daily activities, and can normally withstand much greater stresses for varying lengths of time before failing. However, osteoporosis or a host of other diseases, including such diseases as breast cancer, hemangiomas, osteolytic metastases or spinal myeloma lesions, as well as the long term excessive use of alcohol, tobacco and/or various drugs, can affect and significantly weaken healthy bone over time. If unchecked, such factors can degrade bone strength to a point where the bone is especially prone to fracture, collapse and/or is unable to withstand even normal daily stresses. Unfortunately, losses in bone strength are often difficult to discover until bone integrity has already been seriously compromised. For instance, the effects of osteoporosis are often not discovered until after a bone fracture has already occurred, at which time much of the patient's overall bone strength has typically weakened to dangerous levels. Moreover, as most bone development occurs primarily during childhood and early adulthood, long-term losses in bone strength are typically irreversible. In addition, many bone diseases, including osteoporosis, cancer, and other bone-related disorders, are not routinely curable at our current stage of medical development. For many individuals in our aging world population, undiagnosed and/or untreatable bone strength losses have already weakened these individuals' bones to a point that even normal daily activities pose a significant threat of fracture. For example, when the bones of the spine are sufficiently weakened, the compressive forces in the spine can often cause fracture and/or deformation of the vertebral bodies. For sufficiently weakened bone, even normal daily activities like walking down steps or carrying groceries can cause a collapse of one or more spinal bones, much like a piece of chalk collapses under the compressive weight of a human foot. A fracture of the vertebral body in this manner is typically referred to as a vertebral compression fracture. Researchers estimate that at least 25 percent of all women, and a somewhat smaller percentage of men, over the age of 50 will suffer one or more vertebral compression fractures due to osteoporosis alone. In the United States, it is estimated that over 700,000 vertebral compression fractures occur each year, over 200,000 of which require some form of hospitalization. Other commonly occurring fractures resulting from weakened bones can include hip, wrist, knee and ankle fractures, to name a few. Fractures such as vertebral compression fractures often result in episodes of pain that are chronic and intense. Aside from the pain caused by the fracture itself, the involvement of the spinal column can result in pinched and/or damaged nerves, causing paralysis, loss of function, and intense pain which radiates throughout the patient's body. Even where nerves are not affected, however, the intense pain associated with all types of fractures is debilitating, resulting in a great deal of stress, impaired mobility and other long-term consequences. For example, progressive spinal fractures can, over time, cause serious deformation of the spine (“kyphosis”), giving an individual a hunched-back appearance, and can also result in significantly reduced lung capacity and increased mortality. Until recently, treatment options for vertebral compression fractures, as well as other serious fractures and/or losses in bone strength, were extremely limited—mainly pain management with strong oral or intravenous medications, reduced activity, bracing and/or radiation therapy, all with mediocre results. Because patients with these problems are typically older, and often suffer from various other significant health complications, many of these individuals are unable to tolerate invasive surgery. In addition, to curb further loss of bone strength, many patients are given hormones and/or vitamin/mineral supplements—again with mediocre results and often with significant side effects. Over the past decade, a technique called vertebroplasty has been introduced into the United States. Vertebroplasty involves the injection of a flowable reinforcing material, usually polymethylmethacrylate (PMMA—commonly known as bone cement), into a fractured, weakened, or diseased vertebral body. Shortly after injection, the liquid filling material hardens or polymerizes, desirably supporting the vertebral body internally, alleviating pain and preventing further collapse of the injected vertebral body. While vertebroplasty has been shown to reduce some pain associated with vertebral compression fractures, this procedure has certain inherent drawbacks. The most significant danger associated with vertebroplasty is the inability of the practitioner to control the flow of liquid bone cement during injection into a vertebral body. Although the location and flow patterns of the cement can be monitored by CT scanning or x-ray fluoroscopy, once the liquid cement exits the injection needle, it naturally follows the path of least resistance within the bone, which is often through the cracks and/or gaps in the cancellous and/or cortical bone. Moreover, because the cancellous bone resists the injection of the bone cement and small diameter needles are typically used in vertebroplasty procedures, extremely high pressures are required to force the bone cement through the needle and into the vertebral body. Bone cement, which is viscous, is difficult to inject through small diameter needles, and thus many practitioners choose to “thin out” the cement mixture to improve cement injection, which ultimately exacerbates the leakage problems. In a recent study where 37 patients with bone metastases or multiple myeloma were treated with vertebroplasty, 72.5% of the procedures resulted in leakage of the cement outside the vertebral body. Cortet B. et al., Percutaneous Vertebroplasty in Patients With Osteolytic Metastases or Multiple Myeloma (1998). Moreover, where the practitioner attempts to “thin out” the cement by adding additional liquid monomer to the cement mix, the amount of unpolymerized or “free” monomer increases, which can ultimately be toxic to the patient. Another drawback of vertebroplasty is due to the inability to visualize (using CT scanning or x-ray fluoroscopy) the various venous and other soft tissue structures existent within the vertebra. While the position of the needle within the vertebral body is typically visualized, the location of the venous structures within the vertebral body are not. Accordingly, a small diameter vertebroplasty needle can easily be accidentally positioned within a vein in the vertebral body, and liquid cement pumped directly into the venous system, where the cement easily passes out the anterior and/or posterior walls of the vertebrae through the anterior external venous plexus or the basivertebral vein. Another significant drawback inherent in vertebroplasty is the inability of this procedure to restore the vertebral body to a pre-fractured condition prior to the injection of the reinforcing material. Because the bone is fractured and/or deformed, and not repositioned prior to the injection of cement, vertebroplasty essentially “freezes” the bone in its fractured condition. Moreover, it is highly unlikely that a traditional vertebroplasty procedure could be capable of restoring significant pre-fracture anatomy—because bone cement flows towards the path of least resistance, any en-masse movement of the cortical bone would likely create gaps in the interior and/or walls of the vertebral body through which the bone cement would then immediately flow. A more recently developed procedure for treating fractures such as vertebral compression fractures and other bone-related disorders is known as Kyphoplasty™. See, for example, U.S. Pat. Nos. 4,969,888 and 5,108,404. In Kyphoplasty, an expandable body is inserted through a small opening in the fractured or weakened bone, and then expanded within the bone. This procedure compresses the cancellous bone, and desirably moves the fractured bone to its pre-fractured orientation, creating a cavity within the bone that can be filled with a settable material such as cement or any number of synthetic bone substitutes. In effect, the procedure “sets” the bone at or near its pre-fracture position and creates an internal “cast,” protecting the bone from further fracture and/or collapse. This procedure is of course suitable for use in various other bones as well. While Kyphoplasty can restore bones to a pre-fractured condition, and injected bone filler is less likely to leak out of the vertebral body during a Kyphoplasty procedure, Kyphoplasty requires a greater number of surgical tools than a vertebroplasty procedure, at an increased cost. Moreover, Kyphoplasty tools are typically larger in diameter than vertebroplasty tools, and thus require larger incisions and are generally more invasive. SUMMARY OF THE INVENTION The present invention overcomes many of the problems and disadvantages associated with current strategies and designs in medical procedures to repair, reinforce and/or treat weakened, diseased and/or fractured bone. One aspect of the invention provides a method comprising compressing at least a portion of a cancellous bone volume within a bone structure, e.g., a vertebral body by injecting a bone filler material into the cancellous bone volume. In one embodiment, the method comprises moving fractured cortical bone of the bone structure by injecting bone filler material into the cancellous bone volume. The method includes moving fractured cortical bone to a pre-fractured position. The bone filler material can comprise, e.g., at least one of a bone filler, a bone cement, a synthetic bone substitute, a bone biomaterial, a hydroxyapatite material, a bone mineral material, a thixotropic material, a curable bio-material, allograft tissue, and autograft tissue. Other objects, advantages, and embodiments of the invention are set forth in part in the description which follows, and in part, will be obvious from this description, or may be learned from the practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a spine with a compression fracture in one vertebrae; FIG. 2 is a diagram of a patient about to undergo surgery; FIG. 3 is a lateral view, partially broken away and in section, of a lumbar vertebra depicting a compression fracture; FIG. 4 is a coronal view of a lumbar vertebra; FIG. 5A is a lateral view of a lumbar vertebra depicting a spinal needle inserted into the vertebral body; FIG. 5B is a lateral view of the lumbar vertebra of FIG. 5A, with the stylet removed from the spinal needle; FIG. 5C is a lateral view of the lumbar vertebra of FIG. 5B, with a cavity-forming device constructed in accordance with one embodiment of the present invention inserted into the vertebral body; FIG. 5D is a lateral view of the lumbar vertebra of FIG. 5C, with the cavity-forming device inflated; FIG. 5E is a lateral view of the lumbar vertebra of FIG. 5D, with the cavity-forming device deflated; FIG. 5F is a lateral view of the lumbar vertebra of FIG. 5E, with the cavity-forming device removed from the vertebral body; FIG. 5G is a lateral view of the lumbar vertebra of FIG. 5F, with a bone filler injected into the vertebral body; FIG. 5H is a lateral view of the lumbar vertebra of FIG. 5G, with the spinal needle advanced into the cavity; FIG. 5I is a lateral view of the lumbar vertebra of FIG. 5H, with a second bone filler injected into the vertebral body; FIG. 5J is a lateral view of the lumbar vertebra of FIG. 5I, with additional bone filler injected into the vertebral body; FIG. 5K is a lateral view of the lumbar vertebra of FIG. 5J, with additional bone filler injected into the vertebral body; FIG. 5L is a lateral view of the lumbar vertebra of FIG. 5K, with the spinal needle removed from vertebral body; FIG. 6A is a side view of a cavity-forming device constructed in accordance with an alternate embodiment of the present invention; FIG. 6B is a close-up view of the distal end of the cavity-forming device of FIG. 6A; FIG. 7A is a lateral view of a lumbar vertebra, depicting the cavity-forming device of FIG. 6A being inserted into the vertebra; FIG. 7B is a lateral view of the lumbar vertebra of FIG. 7A, with the cavity-forming device deployed within the vertebra; FIG. 7C is a lateral view of the lumbar vertebra of FIG. 7B, with the cavity-forming device withdrawn from the vertebra; FIG. 8A is a lateral view of a lumbar vertebra, depicting an alternate procedure for treating a vertebral body in accordance with the teachings of the present invention; FIG. 8B is a lateral view of the lumbar vertebra of FIG. 8A, with a cavity-forming device inserted into the bone filler; FIG. 8C is a lateral view of the lumbar vertebra of FIG. 8B, with the cavity-forming device expanded in the cavity; FIG. 9 is a side view of a cavity-forming device constructed in accordance with one embodiment of the present invention; FIG. 10 is a close-up view of the distal end of a cavity-forming device of FIG. 9; FIG. 11 is a close-up view of the distal end of a balloon catheter protruding from the distal end of a needle, depicting the inflation of the balloon material with an inflation medium; FIG. 12 is a side view of a cavity-forming device constructed in accordance with an alternate embodiment of the present invention; FIG. 13 is a side view of a cavity-forming device constructed in accordance with another alternate embodiment of the present invention; FIG. 14 is a side view of a cavity-forming device constructed in accordance with another alternate embodiment of the present invention; FIG. 15 is a side view of a cavity-forming device constructed in accordance with another alternate embodiment of the present invention; FIG. 16A is a lateral view of a lumbar vertebra, depicting an alternate procedure for treating a vertebral body in accordance with the teachings of the present invention; FIG. 16B is a lateral view of the lumbar vertebra of FIG. 16A, with bone filler injected into the vertebra; FIG. 16C is a lateral view of the lumbar vertebra of FIG. 16B, with a cavity-forming device inserted into the vertebra; FIG. 16D is a lateral view of the lumbar vertebra of FIG. 16C, with the cavity-forming device expanded in the cavity; FIG. 17 is a side view of a cavity-forming device constructed in accordance with another alternate embodiment of the present invention; FIG. 18 is a side view of a cavity-forming device constructed in accordance with another alternate embodiment of the present invention; FIG. 19 is a cross-sectional view of the cavity-forming device of FIG. 18, taken along line 19-19; and FIG. 20 is a cross-sectional view of the cavity-forming device of FIG. 18, taken along line 20-20. DESCRIPTION OF THE INVENTION As embodied and broadly described herein, the present invention is directed to surgical methods for repairing, reinforcing and/or treating weakened, diseased and/or fractured bone. The present invention is further directed to various devices for facilitating such surgical methods. FIG. 1 depicts a typical human spine 1, in which a compression fracture 10 has occurred in a lumbar vertebra 100. As best shown in FIG. 3, vertebra 100 has fractured, with the top and bottom plates 103 and 104 depressing generally towards the anterior wall 10 of the vertebra 100 and away from their pre-fracture, normally parallel orientation (indicated generally as parallel lines 90). FIG. 4 depicts a coronal (top) view of the vertebra of FIG. 3. Vertebra 100 includes a vertebral body 105, which extends on the anterior (i.e. front or chest) side of the vertebra 100. Vertebral body 105 is approximately the shape of an oval disk, with an anterior wall 10 and a posterior wall 261. The geometry of the vertebral body 105 is generally symmetric. Vertebral body 105 includes an exterior formed from compact cortical bone 110. The cortical bone 110 encloses an interior volume of reticulated cancellous, or spongy, bone 115 (also called medullar bone or trabecular bone). The spinal canal 150 is located on the posterior (i.e. back) side of each vertebra 100. The spinal cord 151 passes through the spinal canal 150. A vertebral arch 135 surrounds the spinal canal 150. Left and right pedicles 120 of the vertebral arch 135 adjoin the vertebral body 105. The spinous process 130 extends from the posterior of the vertebral arch 135, as do the left and right transverse processes 125 and the mamillary processes 126. FIG. 2 depicts a patient 50 prepared for disclosed methods of the present invention. These procedures can be performed on an outpatient or inpatient basis by a medical professional properly trained and qualified to perform the disclosed procedures. Desirably, the patient will be placed under general or local anesthetic for the duration of the surgical procedures. In one embodiment of the present invention, a surgical method comprises inserting an insertion device 350 (see FIG. 5A) percutaneously into the bone, such as a fractured vertebral body 105 through, preferably, a targeted area of the back, depicted as 60 in FIG. 2. The insertion device 350 may be any type and size of hollow instrument, preferably having a sharp end. In one preferred embodiment, the insertion device 350 comprises a hollow needle of approximately eleven gauge diameter. An eleven gauge needle is preferred for the procedure because it incorporates a hollow lumen of sufficient size to permit the passage of various instruments and materials, yet the overall size of the needle is small enough to minimize bone and tissue damage in the patient. It should be understood, however, that various other size needle assemblies, including needles of six to 14 gage, could be used with the devices and methods of the present invention, with varying results. In addition, various other access instruments, such as those described in U.S. Pat. Nos. 4,969,888, 5,108,404, 5,827,289, 5,972,015, 6,048,346 and 6,066,154, each of which are incorporated herein by reference, could be used in accordance with the teachings of the present invention, with varying results. The insertion device 350 is preferably comprised of a strong, non-reactive, and medical grade material such as surgical steel. If desired, the insertion device 350 is attached to a manipulating assembly which is comprised of a non-reactive and medical grade material including, but not limited to, acrylonitrile-butadiene-styrene (ABS), polyethylene, polypropylene, polyurethane, Teflon, or surgical steel. FIG. 5A depicts a commercially available needle assembly typically used with various embodiments of the present invention, which are further described below. As shown in FIG. 5A, an insertion device 350, such as an eleven gauge biopsy needle (commercially available from Becton Dickinson & Co of Franklin Lakes, N.J.) can be inserted through soft tissues of the back and into the vertebral body 105. Generally, the approach for such a procedure will be transpedicular, although various other approaches, including lateral, extrapedicular and/or anterior approaches, could be used, depending upon the level treated and/or intervening anatomical features well known to those of ordinary skill in the art. In one embodiment, the device 350 comprises a needle body 348 and a stylet 349, as is well known in the art. During insertion of the device 350, the location of the device 350 is desirably monitored using visualization equipment such as real-time X-Ray, CT scanning equipment 70 (see FIG. 2), MRI, or any other monitoring equipment commonly used by those of skill in the art, including computer aided guidance and mapping equipment such as the systems commercially available from BrainLab Corporation or General Electric Corporation. In one preferred embodiment, the distal end 351 of the insertion device 350 is positioned in the vertebral body 105, preferably at a location towards the posterior side of the vertebral body 105. If desired, the distal end 351 could be positioned in various locations throughout the vertebral body 105, including towards the anterior side. Once in position, the stylet 349 of the insertion device 350 may be removed, see FIG. 5B, and a cavity-forming device 200 may be inserted through the shaft 348 and into the vertebral body 105. See FIG. 5C. The cavity-forming device 200, which is desirably comprised of a biologically compatible and medically acceptable material, can be a small mechanical tamp, reamer, hole punch, balloon catheter (as described below) or any appropriate device which is capable of displacing cancellous bone. Once the cavity-forming device is positioned within the vertebral body 105, it is used to displace cancellous bone 115, thereby creating a cavity 170. See FIG. 5F. In one embodiment, shown in FIGS. 9 and 10, the cavity-forming device comprises a balloon catheter 200. The balloon catheter 200 desirably extends across at least 20% of the vertebral body, but could extend greater or lesser amounts, depending upon the desired size of the cavity to be produced. In this embodiment, as the balloon catheter 201 is expanded, cancellous bone is displaced generally outward from the cavity 170 in a controlled manner, desirably forming a compressed-bone region 172 around a substantial portion of the outer periphery of the cavity 170. The balloon catheter 200, which will be described in more detail below, is sized or folded to fit through the hollow interior of the shaft 348 and into a vertebral body 105. Once in a desired position within the vertebral body 105, the balloon catheter 190 is filled with a pressurized filling medium 275 appropriate for use in medical applications including, but not limited to, air, nitrogen, saline or water. See FIGS. 5D and 11. In a preferred embodiment, the filling medium 275 is a radiopaque fluid (such as Conray® fluid available commercially from Mallinkrodt, Inc., of St. Louis, Mo.), which allows the physician to visualize the catheter 190 during inflation. If desired, alternate ways of expanding the catheter, including mechanical expanders, jacks, expanding springs and/or expanding/foaming agents, could be used, with varying results. In one embodiment, the catheter 201 is expanded to any appropriate volume which creates a cavity 170 within the vertebral body 105. In a preferred embodiment, the catheter 201 is expanded to at least 0.20 cc in volume, but could be expanded to significantly greater sizes, such as 1, 2, 4, 6 or 8 cc, depending upon bone quality and density. After cavity creation, the catheter 201 is deflated (see FIG. 5E) and removed from the vertebral body 105 and shaft 348 (see FIG. 5F). Bone filler 180 is introduced through the shaft 348 and into the vertebral body 105 using any type of plunger, extruder and/or feed line assembly 349 compatible with the needle body 348. Once injection of bone filler is complete, the shaft 348 can be withdrawn. If desired, a portion of the balloon catheter 201 could be temporarily or permanently left within a vertebral body 105. For example, after cavity formation and removal of the inflation medium, the deflated expanded section of the balloon catheter 201 could be refilled with bone filler 180 and left within the vertebral body 105. Alternatively, the inflation medium 275 could comprise bone filler 180. After the balloon catheter 201 is filled with such an inflation medium, at least a portion of the catheter 201 could be left permanently within the cavity 170. In an alternate embodiment, the catheter 201 which is intended to remain with the cavity 170 could comprise a bio-absorbable material and/or fabric/mesh material as the expandable structure. In creating the cavity 170, the inflation of the catheter 201 causes the expandable material 210 to press against the cancellous bone 115 which may form a compressed bone region or “shell” 172 along much of the periphery of the cavity 170. This shell 172 will desirably inhibit or prevent bone filler 180 from exiting the cavity 170, thereby inhibiting extravazation of the bone filler and/or facilitating pressurization of the bone filler 180, if desired, within the cavity. As the pressure in the cavity 170 increases, the walls of the cavity 170 will desirably be forced further outward by the bone filler 180, compressing additional cancellous bone within the vertebral body 105 and/or increasing the size of the cavity 170. If sufficient pressure is available, and integrity of the shell 172 can be maintained without significant leakage of bone filler 180, pressures capable of moving fractured cortical bone can be developed. In one embodiment of the present invention, after cavity formation, an amount of a material, such as a bone filler 180, is introduced through the shaft 348 into the vertebral body 105 under low pressure. The amount of bone filler will desirably be more than the volume of the cavity 170, however, less bone filler may be introduced with varying results. Once the cavity 170 is substantially filled, the continued introduction of bone filler 180 will desirably pressurize the bone filler 180 in the cavity 170 such that the increased pressure will cause at least a portion of the walls of the cavity to move outward, thereby enlarging the cavity 170 and further compressing cancellous bone and/or moving cortical bone. Desirably, introduction of the bone filler 180 will continue until bone filler leak from the vertebral body appears imminent, the cortical bone has regain its pre-fractured position and/or the practitioner determines that sufficient bone filler 180 has been injected into the bone. If desired, the physician can utilize the cavity-forming device to create additional cavities for bone filler, or the shaft 348 can be removed from the vertebral body to completed the procedure. The bone filler 180 could be any appropriate filling material used in orthopedic surgery, including, but not limited to, allograft or autograft tissue, hydroxyapatite, epoxy, PMMA bone cement, or synthetic bone substitutes such Osteoset® from Wright Medical Technology, medical grade plaster of paris, Skeletal Repair System (SRS®) cement from Norian Corporation, or Collagraft from Zimmer. As bone filler 180 is introduced into the vertebral body 105, the introduction is desirably monitored by x-ray fluoroscopy, or any other appropriate monitoring device or method, to ensure that bone filler 180 does not flow outside of the vertebral body 105. To facilitate visualization, the bone filler 180 may be mixed with a fluoroscopic agent, such as radio opaque barium sulfate. In another embodiment, the bone filler 180 could comprise a mixture of bone cement and a thixotropic material which desirably limits and/or prevents extravazation of the bone cement. In an alternate embodiment of the disclosed method, shown in FIGS. 5G through 5L, a first bone filler 180 is introduced into the cavity 170, the amount of first bone filler 180 being desirably less than or approximately equal to the volume of the cavity 170. For example, if the balloon catheter 200 utilized to create the cavity 170 was inflated with 1.0 cc of inflation fluid, then less than or approximately 1.0 cc of bone filler 180 will initially be injected into the cavity 170. Of course, if desired, an amount of first bone filler 180 greater than the cavity volume could be injected into the cavity. The shaft 348 is then repositioned within the vertebral body 105, see FIG. 5H, with the distal end 351 of the device 350 desirably located within the bolus 400 of first bone filler 180 contained in the cavity 170. As best shown in FIG. 5I, a second amount of bone filler 182 is then injected into the vertebral body 105, which desirably forces the first amount of bone filler 180 outward against the walls of the cavity 170. Desirably, the first amount of bone filler 180 will resist extravazating out of the cavity 170 and will push outward against the walls of the cavity 170, further compressing the cancellous bone 115 and/or increasing the size of the cavity 170. Introduction of the second amount of bone filler 182 will desirably continue until bone filler leak from the vertebral body appears imminent, the cortical bone has regained its pre-fractured position, and/or the practitioner determines that sufficient bone filler 180 has been injected into the bone. If desired, the physician could reinsert a catheter 200 to create an additional cavity, or the shaft 348 can be removed to complete the procedure. FIGS. 8A through 8C depict an alternate embodiment of the disclosed method, in which the practitioner introduces a first material, such as a bone filler 180, into the cavity 170, and subsequently inserts a cavity-forming device 200 into the bone. The cavity-forming device 200 is then expanded, and desirably compresses the bone filler 180 against the walls of the cavity, sealing any significant cracks and/or venous passages through which the cement will flow. In one further embodiment, a practitioner may wait to allow the first bone filler to harden partially or fully prior to removing the cavity-forming device and/or prior to introducing a second material, such as a bone filler. The second material (not shown) can subsequently be injected into the vertebral body with little fear of leakage. If desired, this method could be utilized whenever cement leakage appears imminent, and can be repeated multiple times until the practitioner determines that sufficient bone filler 180 has been injected into the bone. In addition, the practitioner could repeat this procedure until the cortical bone has regained its pre-fractured position. In an alternate embodiment, the practitioner could utilize a cavity-forming device prior to the introduction of the first bone filler, and then introduce the first bone filler into the cavity, subsequently follow one or more of the described methods. The first bone filler will desirably comprise a material that can be introduced into the cavity, but which will resist extravazation out of the cavity and/or vertebral body when the second bone filler is injected into the cavity. In one embodiment of the invention, the first and second bone fillers comprise bone cement, with the first bone cement being more resistant to extravazation than the second bone cement. For example, the ingredients of the first bone cement could be specifically tailored such that the first bone cement cures faster than the second bone cement. Alternatively, the first bone cement could be prepared and/or introduced into the vertebral body before the second bone cement, allowing the first bone cement to partially or fully cure before the second bone cement. Alternatively, the curing and/or hardening of the first bone cement could be accelerated (by applying heat, for example) or curing and/or hardening of the second bone cement could be retarded (by cooling, for example). In another embodiment, the first and second bone fillers comprise bone cement, with the first bone cement desirably being more viscous than the second bone cement. In another alternate embodiment, the first bone filler comprises an expandable structure, such as a stent. In another embodiment, the first bone filler comprises a material more viscous than the second bone filler, the first and second bone fillers comprising different materials. In another embodiment, the first bone filler comprises a material which is more resistant to extravazation into the cancellous bone than the second bone filler. In another embodiment, the first bone filler comprises a material having particles generally larger than particles in the second bone filler. In a further embodiment, the particles of the first bone filler are generally larger than the average pore size within the cancellous bone. In another embodiment, the first bone filler comprises a settable material, such as a two-part polyurethane material or other curable bio-material. FIGS. 16A through 16D depict an alternate embodiment of the disclosed method, in which a first material, such as a bone filler 180, is initially introduced into the cancellous bone 115 of a human bone, such as a vertebral body 105. An expandable structure 210, such as that found at the distal end of a balloon catheter 200, is subsequently inserted into the vertebral body 105. The expandable structure 210 is then expanded, which displaces the bone filler 180 and/or cancellous bone 115, creating a cavity 170 within the vertebral body 105. In one embodiment, the expansion of the expandable structure 210 forces the bone filler 180 further into the cancellous bone 115, and/or further compresses cancellous bone. To minimize bone filler 180 leakage, the bone filler may be allowed to partially or completely harden prior to expansion of the expandable structure 210. Alternatively, the expandable structure 210 may be expanded, and the bone filler 180 allowed to partially or completely harden around the expandable structure 210. In either case, a second material, optionally additional bone filler, may be introduced into the cavity 170. In one embodiment, the second material is a material which supports the bone in a resting position. This method may be utilized whenever cement leakage appears imminent, and may be repeated multiple times until the practitioner determines that sufficient amounts and varieties of material have been introduced into the bone. Alternatively, the practitioner could halt introduction of filler material when the cortical bone regains or approximates its pre-fractured position. By creating cavities and/or preferred flow paths within the cancellous bone, the present invention obviates the need for extremely high pressure injection of bone filler into the cancellous bone. If desired, the bone filler could be injected into the bone at or near atmospheric and/or ambient pressures, or at pressures less than approximately 400 pounds per square inch, using bone filler delivery systems such as those described in co-pending U.S. patent application Ser. No. 09/134,323, which is incorporated herein by reference. Thus, more viscous bone fillers (such as, for example, thicker bone cement) can be injected into the bone under low pressures (such as, for example, exiting the delivery device at a delivery pressure at or near ambient or atmospheric pressure), reducing opportunities for cement leakage and/or extravazation outside of the bone. Cavity-Forming Devices The present invention also includes cavity-forming devices constructed in accordance with the teachings of the disclosed invention. In one embodiment, the cavity-forming device comprises a balloon catheter 201, as shown in FIGS. 9, 10, and 11. The catheter comprises a hollow tube 205, which is desirably comprised of a medical grade material such as plastic or stainless steel. The distal end 206 of the hollow tube 205 is surrounded by an expandable material 210 comprised of a flexible material such as commonly used for balloon catheters including, but not limited to, metal, plastics, composite materials, polyethylene, mylar, rubber or polyurethane. One or more openings 250 are disposed in the tube 205 near the distal end 206, desirably permitting fluid communication between the hollow interior of the tube 205 and the lumen formed between the tube 205 and the expandable structure 210. A fitting 220, having one or more inflation ports 222, 224, is secured to the proximal end 207 of the tube 205. In this embodiment, once the catheter 201 is in its desired position within the vertebral body 105, an inflation medium 275 is introduced into the fitting 220 through the inflation port 222, where it travels through the fitting 220, through the hollow tube 205, through the opening(s) 250 and into the lumen 274 between the expandable structure 210 and the hollow tube 205. As injection of the inflation medium 275 continues, the pressure of the inflation medium 275 forces the expandable structure 210 away from the hollow tube 205, inflating it outward and thereby compressing cancellous bone 115 and forming a cavity 170. Once a desired cavity size is reached, the inflation medium 275 is withdrawn from the catheter 200, the expandable structure collapses within the cavity 170, and the catheter 200 may be withdrawn. For example, a balloon catheter 201 constructed in accordance with one preferred embodiment of the present invention, suitable for use with an 11-gauge needle, would comprise a hollow stainless steel hypodermic tube 205, having an outer diameter of 0.035 inches and a length of 10.75 inches. One or more openings 250 are formed approximately 0.25 inches from the distal end of the tube 205. In a preferred embodiment, the distal end 206 of the hollow tube 205 is sealed closed using any means well known in the art, including adhesive (for example, UV 198-M adhesive commercially available from Dymax Corporation—cured for approximately 15 minutes under UV light). In one embodiment, the hollow tube 205 is substantially surrounded by an expandable structure 210 comprising an extruded tube of polyurethane (for example, TEXIN® 5290 polyurethane, available commercially from Bayer Corporation). In one embodiment, the polyurethane tube has an inner diameter of 0.046 inches, an outer diameter of 0.082 inches, and a length of 9½ inches. The distal end of the polyurethane tube is bonded to the distal end 206 of the hollow tube 205 by means known in the art, such as by a suitable adhesive (for example, UV 198-M adhesive). Alternatively, the polyurethane tube may be heat sealed about the distal end 206 of the hollow tube 205 by means well known in the art. A ¾ inch long piece of heat shrink tubing 215 (commercially available from Raychem Corporation), having a 3/16 inch outer diameter, may be secured around the proximal end of the polyurethane tubing. In one embodiment, the proximal end of the hollow tubing 205 is inserted into the fitting 220 and the heat shrink tubing 215 is desirably bonded into the fitting 220 using a suitable adhesive known in the art, such as UV 198-M. The fitting 220, which may be a Luer T-fitting, commercially available from numerous parts suppliers, may be made of any appropriate material known to those of skill in the art. The fitting 220 comprises one or more ports 222, 224 for attachment to additional instruments, such as pumps and syringes (not shown). If desired, the hollow tube 205 can similarly be bonded into the fitting 220 using a suitable adhesive. Alternatively, as shown in FIG. 12, the expandable structure 210 could be significantly shorter than the hollow tube 205 and be bonded at its distal end 206 and its proximal end 209 to the hollow tube 205. The hollow tube 205 and one or more openings 250 facilitate the withdrawal of inflation medium from the catheter during the disclosed procedures. When a catheter is deflated, the expandable structure 210 will normally collapse against the tube 205, which can often seal closed the lumen (in the absence of at least one secondary withdrawal path) and inhibit further withdrawal of inflation medium from the expanded structure 210 of a catheter. However, in an embodiment of the disclosed invention, the one or more openings 250 near the distal end of the tube 205 allow inflation medium 275 to be drawn through the hollow hypodermic tube 205, further deflating the expandable structure 210. The strong walls of the hollow hypodermic tube 205 resist collapsing under the vacuum which evacuates the inflation medium, maintaining a flow path for the inflation medium and allowing the inflation medium to be quickly drawn out of the catheter, which desirably permits deflation of the catheter in only a few seconds. In the disclosed embodiment, as the catheter 201 is inflated, the inflation medium 275 will typically seek to fill the entire lumen between the expandable structure 210 and the hollow tube 205, thus expanding the catheter 201 along the entire length of the expandable structure 210. However, because much of the catheter 201 is located within the lumen of the shaft 348, with the distal end 206 of the catheter 201 extending into the vertebral body 105, the shaft 348 will desirably constrain expansion of the expandable structure 210, causing the expandable structure 210 to expand primarily at the distal end 206 of the catheter 200. Desirably, further insertion or withdrawal of the catheter 201 will alter the amount of the expandable structure 210 extending from the distal end of the shaft 348, thereby increasing or decreasing the length of the expandable structure 210 that is free to expand within the vertebral body 105. By choosing the amount of catheter 201 to insert into the vertebral body 105, the practitioner can alter the length of the expandable structure, and ultimately the size of the cavity 170 created by the catheter 201, during the surgical procedure. Therefore, the disclosed embodiments can obviate and/or reduce the need for multiple catheters of varying lengths. If desired, markings 269 (see FIG. 9) can be placed along the proximal section of the catheter which correspond to the length of the catheter 201 extending from the shaft 348, allowing the practitioner to gauge the size of the expandable structure 210 of the catheter 200 within the vertebral body 105. Similarly, in an alternate embodiment as disclosed below, the cavity-forming device 201 could incorporate markings corresponding to the length of the bristles 425 extending beyond the tip of the shaft 348. In an alternate embodiment, shown in FIG. 13, the length of an expandable section 211 of the catheter can be further constrained by securing and/or adhering the expandable structure 210 at a secondary location 214 along the hollow tube 205, thereby limiting expansion beyond the secondary location 214. For example, if a desired maximum length of the expandable section 211 were 3 inches, then the expandable structure 210 could be secured to the hollow tube 205 at a secondary location 214 approximately three inches from the distal end 206 of the hollow tube 205. This arrangement would desirably allow a practitioner to choose an expanded length of the expandable section 211 of up to three inches, while limiting and/or preventing expansion of the remaining section 203 of the catheter 201. This arrangement can also prevent unwanted expansion of the portion 202 of the catheter extending out of the proximal end 191 of the shaft body 348 (see FIG. 5C). As previously noted, in the disclosed embodiment, the expandable structure is desirably secured to the distal end of the hollow tube, which will facilitate recovery of fragments of the expandable structure 210 if the expandable structure 210 is torn or damaged, such as by a complete radial tear. Because the hollow tube 205 will desirably remain attached to the fragments (not shown) of the expandable structure 210, these fragments can be withdrawn from the vertebral body 105 with the hollow tube 205. In addition, the distal attachment will desirably prevent and/or reduce significant expansion of the expandable structure 210 along the longitudinal axis of the hollow tube 205. FIG. 17 depicts a cavity-forming device 300 constructed in accordance with an alternate embodiment of the present invention. Because many of the features of this embodiment are similar to embodiments previously described, like reference numerals will be used to denote like components. In this embodiment, the hollow tube 205 extends through the fitting 220, such as a t-shaped fitting, and is secured to a cap 310. In a preferred embodiment, the hollow tube 205 is capable of rotation relative to the fitting 220. If desired, a seal (not shown), such as a silicone or teflon o-ring, can be incorporated into the proximal fitting 222 to limit and/or prevent leakage of inflation medium past the hollow tube 205. In use, a cavity-forming device 300 compresses cancellous bone and/or forms a cavity in a manner similar to the embodiments previously described. However, once the cavity is formed and withdrawal of the device 300 is desired, the cap 310 can be rotated, twisting the expandable material 210 relative to the fitting 220 and drawing the expandable structure 210 against the hollow tube 205, desirably minimizing the overall outside diameter of the expandable portion of the device 300. The device 300 can then easily be withdrawn through the shaft 348. Even where the expandable structure 210 has plastically deformed, or has failed in some manner, the present embodiment allows the expandable structure 210 to be wrapped around the hollow tube 205 for ease of withdrawal and/or insertion. Alternatively, the hollow tube 205 may be capable of movement relative to the longitudinal axis of the fitting 220, which would further stretch and/or contract the expandable structure 210 against the hollow tube 205. FIGS. 6A and 6B depict a cavity-forming device 410 constructed in accordance with an alternate embodiment of the present invention. Cavity-forming device 410 comprises a shaft 420 which is desirably sized to pass through the shaft 348 of an insertion device 350. A handle assembly 415, which facilitates manipulation of the cavity-forming device 410, is secured to the proximal end 412 of the shaft 420. One or more wires or “bristles” 425 are secured to the distal end 423 of the shaft 420. The bristles 425 can be secured to the shaft 420 by welding, soldering, adhesives or other securing means well known in the art. Alternatively, the bristle(s) 425 can be formed integrally with the shaft 420, or can be etched from a shaft using a laser or other means well known in the art. The bristles and shaft may be formed of a strong, non-reactive, and medical grade material such as surgical steel. In one embodiment, the bristles 425 extend along the longitudinal axis of the shaft 425, but radiate slightly outward from the shaft axis. In this manner, the bristles 425 can be collected or “bunched” to pass through the shaft 348, but can expand or “fan” upon exiting of the shaft 348. If desired, the bristles can be straight or curved, to facilitate passage through the cancellous bone 115. In addition, if desired, one or more of the bristles 425 may be hollow, allowing a practitioner to take a biopsy sample of the cancellous bone during insertion of the device 410. As shown in FIG. 7, the cavity-forming device 410 can desirably be inserted through a shaft 348 positioned in a targeted bone, such as a vertebral body 105. As the bristles 425 enter the cancellous bone 115, the bristles 425 will desirably displace the bone 115 and create one or more cavities 426 or preferred flow paths in the vertebral body. If desired, a practitioner can withdraw the bristles 425 back into the shaft 348, reposition the cavity-forming device 410 (such as by rotating the device 410), and reinsert the bristles 425, thereby creating additional cavities in the cancellous bone 115. After removal of the cavity-forming device 410, a material, such as a bone filler (not shown), may be introduced through the shaft 348. The bone filler will desirably initially travel through the cavities 426 created by the bristles 425. If desired, a practitioner may interrupt introduction of the bone filler and create additional cavities by reinserting the cavity-forming device 410. In addition, in the event bone filler leakage occurs or is imminent, a practitioner can interrupt bone filler injection, create additional cavity(ies) as described above, wait for the introduced/leaking bone filler to harden sufficiently to resist further extravazation, and then continue introduction of bone filler. As previously described, the bone filler could comprise many different materials, or combinations of materials, with varying results. FIG. 14 depicts a cavity-forming device 500 constructed in accordance with an alternate embodiment of the present invention. The cavity-forming device 500 comprises a shaft 520 which is sized to pass through the shaft 348 of an insertion device 350. A handle assembly 515, which facilitates manipulation of the cavity-forming device 500, is secured to the proximal end 512 of the shaft 520. The shaft 520 of the cavity-forming device 500 is desirably longer than the shaft 348 of the insertion device 350. The distal end 525 of the shaft 520 can be beveled (not shown) to facilitate passage through cancellous bone 115, or can be rounded or flattened to minimize opportunities for penetrating the anterior wall 10 of the vertebral body 105. In addition, if desired, the distal 525 end of the shaft 520 could be hollow (not shown), allowing the practitioner to take a biopsy sample of the cancellous bone 115 during insertion of the device 500. FIG. 15 depicts a cavity-forming device 600 constructed in accordance with an alternate embodiment of the present invention. Cavity-forming device 600 comprises a shaft 620 which is sized to pass through the shaft 348 of an insertion device 350. A handle assembly 615, which facilitates manipulation of the cavity-forming device 600, is secured to the proximal end 612 of the shaft 620. The shaft 620 is desirably longer than the shaft 348 of insertion device 350. The distal end 625 of the shaft 620 can be beveled (not shown) to facilitate passage through cancellous bone 115, or can be rounded or flattened to minimize opportunities for penetrating the anterior wall 10 of the vertebral body 105. In this embodiment, the distal end 625 of the device 600 incorporates drill threads 627 which can facilitate advancement of the device 600 through cancellous bone 115. In addition, if desired, the distal 625 end of the shaft 620 could be hollow, allowing the practitioner to take a biopsy sample of the cancellous bone 115 during insertion of the device 600. After removal of the device(s), bone filler (not shown) may be introduced through the shaft 348. Desirably, the bone filler will initially travel through the cavity(ies) created by the device(s). If desired, a practitioner can interrupt introduction of bone filler and create additional cavity(ies) by reinserting the device(s). In addition, in the event bone filler leakage occurs or is imminent, the practitioner can interrupt bone filler introduction, create additional cavity(ies) as described above, wait for the introduced/leaking bone filler to harden sufficiently, and then continue introducing bone filler. As previously described, the bone filler could comprise many different materials, or combinations of materials, with varying results. FIGS. 18-20 depicts a cavity-forming device 600a constructed in accordance with another alternate embodiment of the present invention. Because many of the components of this device are similar to those previously described, similar reference numerals will be used to denote similar components. Cavity-forming device 600a comprises a shaft 620a which is sized to pass through the shaft 348 of an insertion device 350. A handle assembly 615a, which facilitates manipulation of the cavity-forming device 600a, is secured to the proximal end 612a of the shaft 620a. The shaft 620a is desirably longer than the shaft 348 of insertion device 350. The distal end 625a of the shaft 620a can be rounded or beveled to facilitate passage through cancellous bone 115, or can be or flattened to minimize opportunities for penetrating the anterior wall 10 of the vertebral body 105. An opening or window 700 is desirably formed in the shaft 620a. As shown in FIGS. 19 and 20, an expandable structure 710 is located at least partially within the shaft 620a, desirably at a position adjacent the window 700. Upon introduction of inflation fluid through a lumen extending through the shaft 620a, the expandable structure 710 expands and at least a portion of the expandable structure 710 will extend out of the shaft 620a through the window 700. Desirably, as the structure continues to expand, the expandable structure 710 will “grow” (P1 to P2 to P3 in FIG. 20) through the window 700, thereby compacting cancellous bone, creating a cavity and/or displacing cortical bone. Upon contraction of the expandable structure 710, most of the expandable structure 710 will desirably be drawn back into the shaft 620a for removal of the tool from the vertebral body. In one embodiment, at least a portion of the material comprising the expandable structure 710 will plastically deform as it expands. The expandable structure 710 may be comprised of a flexible material common in medical device applications, including, but not limited to, plastics, polyethylene, mylar, rubber, nylon, polyurethane, metals or composite materials. Desirably, the shaft 620a will comprise a material that is more resistant to expansion than the material of the expandable structure 710, including, but not limited to, stainless steel, ceramics, composite material and/or rigid plastics. In an alternate embodiment, similar materials for the expandable structure 710 and shaft 620a may be used, but in different thickness and/or amounts, thereby inducing the expandable structure to be more prone to expansion than the shaft 620a material. The expandable structure 710 may be bonded directly to the shaft 620a by various means well known in the art, including, but not limited to, means such as welding, melting, gluing or the like. In alternative embodiments, the expandable structure may be secured inside or outside of the shaft 620a, or a combination thereof. As previously noted, any of the cavity-forming devices 500, 600 and 600a may be inserted through a shaft 348 positioned in a targeted bone, such as a vertebral body 105. As the device(s) enter the cancellous bone 115, they will desirably displace the bone 115 and create one or more cavities in the vertebral body. If desired, the physician can withdraw the device(s) back into the shaft 348 and reinsert as necessary to create the desired cavity(ies) in the cancellous bone 115. In the embodiment of a cavity-forming device of FIGS. 18-20, the cavity-forming device 600a may be utilized without an associated insertion device. In such a case, the cavity-forming device desirably will incorporate a sharpened distal tip capable of penetrating the soft tissues and cortical/cancellous bone of the vertebral body. If desired, the distal tip can be hollow or a solid construct. Similarly, the window may extend around more or less of the periphery of the shaft 620a, depending upon the size and configuration of the expandable structure and the desired strength of the cavity-forming device. By creating one or more cavities within the cancellous bone 115, the cavity-forming devices of the present invention desirably create preferred flow paths for the bone filler 180. In addition, the cavity-forming devices can also desirably close and/or block other natural flow paths out of the cavity, such as veins and/or cracks in the cancellous bone. Moreover, methods and devices disclosed herein can be used to manipulate bone filler already introduced into the bone. Thus, the present invention reduces opportunities for cement leakage outside of the vertebral body and/or improves the distribution of bone filler throughout significant portions of the vertebral body. In addition, the creation of cavities and desired flow paths described in the present invention permits the placement of biomaterial more safely, under greater control and under lower pressures. In addition to the specific uses described above, the cavity-forming devices and methods described herein would also be well-suited for use in treating and/or reinforcing weakened, diseased and/or fractured bones and other organs in various locations throughout the body. For example, the disclosed devices and methods could be used to deliver reinforcing materials and/or medications, such as cancer drugs, replacement bone cells, collagen, bone matrix, demineralized calcium, and other materials/medications, directly to a fractured, weakened and/or diseased bone, thereby increasing the efficacy of the materials, reinforcing the weakened bone and/or speed healing. Moreover, injection of such materials into one bone within a body could permit the medication/material to migrate and/or be transported to other bones and/or organs in the body, thereby improving the quality of bones and/or other organs not directly injected with the materials and/or medications. Other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. All documents referenced herein are specifically and entirely incorporated by reference. The specification and examples should be considered exemplary only with the true scope and spirit of the invention indicated by the following claims. As will be easily understood by those of ordinary skill in the art, variations and modifications of each of the disclosed embodiments can be easily made within the scope of the claims.
|
A
|
A61
|
A61B
|
17
|
58
|
|||
11727756
|
US20070228811A1-20071004
|
Auxiliary drive for a trailer
|
ACCEPTED
|
20070919
|
20071004
|
[]
|
B60B3516
|
["B60B3516"]
|
7931100
|
20070328
|
20110426
|
180
|
014200
|
65482.0
|
ARCE
|
MARLON
|
[{"inventor_name_last": "Bender", "inventor_name_first": "Helmuth", "inventor_city": "Eschenurg", "inventor_state": "", "inventor_country": "DE"}, {"inventor_name_last": "Bender", "inventor_name_first": "Steffen", "inventor_city": "Eschenburg", "inventor_state": "", "inventor_country": "DE"}, {"inventor_name_last": "van Schie", "inventor_name_first": "Michael", "inventor_city": "Delft", "inventor_state": "", "inventor_country": "NL"}]
|
In an auxiliary drive for a trailer such as a caravan, the drive consists of a drive unit with a gearwheel. Through linear movement of the drive unit relative to the chassis, the gearwheel can be brought into engagement with a ring gear fitted either on the brake drum of a wheel of the vehicle or on an auxiliary part such as a covering drum fitted over the brake drum. The ring gear preferably lies in a plane outside the plane bounded by the inside of the wheel.
|
1. Auxiliary part for an auxiliary drive for a trailer such as a caravan, comprising a drum part, which on one free end is provided with a ring gear fitted on its outer circumference, and on the other free end is provided with a bottom having at least three bolt holes lying equally spaced on a pitch circle, said drum being provided with cooling air apertures between the two free ends. 2. Auxiliary drive for a trailer such as a caravan, comprising a drive unit provided with gear teeth and an auxiliary part to be connected to the wheel/hub of said trailer, which auxiliary part is provided with gear teeth which can interact with the gear teeth of said drive unit, said auxiliary part comprising a drum part, which on one free end is provided with a ring gear fitted on its outer circumference, and on the other free end is provided with a bottom, said bottom being provided with at least three bolt holes lying equally spaced on a pitch circle, said drum being provided with cooling air apertures between the two free ends. 3. A trailer comprising a chassis, an axle and an auxiliary drive, said axle being provided with a brake system comprising brake drums and wheels provided on said axle, said auxiliary drive comprising a drive unit provided with gear teeth and an auxiliary part to be fitted over said brake drum, the internal diameter of said auxiliary part being greater than the external diameter of said brake drum, said auxiliary part comprising a drum part, which on one free end is provided with a ring gear fitted on its outer circumference, and on the other free end is provided with a bottom having at least three bolt holes lying equally spaced on a pitch circle and corresponding to the pattern of the holes/bolts of said brake drum. 4. The trailer according to claim 3, wherein said drum part is provided with apertures (21) between its free ends. 5. A trailer comprising a chassis, an axle and an auxiliary drive, said axle being provided with a drum having circumferential gear teeth and a wheel provided on said drum, said gear teeth extending outside the outer plane of the tyre of said wheel, and comprising a drive unit provided with a gearwheel, said drive unit being fitted so that it can move in order to engage with said gear teeth of said drum. 6. The trailer according to claim 3, wherein said drive unit can be moved in a direction substantially perpendicular to the direction of the axis of said wheel/drum. 7. The trailer according to claim 3, in which said drive unit can be moved substantially parallel to the direction of travel. 8. The trailer according to claim 7, wherein said drive unit can be moved linearly. 9. The trailer according to claim 3, comprising a single drive motor for achieving said linear movement and driving said gearwheel. 10. The trailer according to claim 3, wherein said drive motor is provided on a slide for linear displacement relative to said chassis. 11. The trailer according to claim 10, wherein said motor is provided on an auxiliary member being connected through a biasing member to said slide. 12. The trailer according to claim 11, wherein said biasing member comprises a tensioning spring (pull spring). 13. The trailer according to claim 3, wherein said drum comprises a brake drum. 14. The trailer according to claim 5, wherein said drive unit can be moved in a direction substantially perpendicular to the direction of the axis of said wheel/drum. 15. The trailer according to claim 5, in which said drive unit can be moved substantially parallel to the direction of travel. 16. The trailer according to claim 5, comprising a single drive motor for achieving said linear movement and driving said gearwheel. 17. The trailer according to claim 5, wherein said drive motor is provided on a slide for linear displacement relative to said chassis. 18. The trailer according to claim 5, wherein said drum comprises a brake drum.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to an auxiliary drive for a trailer. Such an auxiliary drive, for example for a caravan, is generally known in the prior art. It has long been a recognized problem that after uncoupling from a towing vehicle, manoeuvring of heavier trailers in particular constitutes a problem, which can be solved by using relatively small electric motors, which drive the wheels of the trailer. In the prior art the use of drive rollers that are connected to the electric motors and engage the tyre of the wheel is generally proposed. The problem is, however, that considerable pressure forces are necessary to prevent slipping between the drive rollers and the wheels. The fact is that driving of the wheels is required most in difficult circumstances in which such wheels are on soggy ground or the like, when the grip between wheel and drive roller will also be far from optimum. It is felt by some that the pressure of the roller against the tyre can cause damage to the tyre in the long run. Moreover, such a drive is easily damaged. For that reason, British Patent Specification 2,305,408 proposes a drive in which the brake drum of the wheel is provided with a ring gear, and an auxiliary shaft extending parallel to the wheel axle is present. The auxiliary shaft is provided with a gearwheel on both sides, which gearwheel engages with the abovementioned ring gear, on the one hand, and with an auxiliary drive lying inside the chassis, on the other hand. By movement in the axial direction, engagement or disengagement can be achieved. Such a structure avoids the problem of failing contact between roller and tyre, but it has the disadvantage that such a system is not easily universally usable. Moreover, the position of the spring-loaded wheel relative to the chassis constitutes a problem for the positioning of the auxiliary drive.
|
<SOH> SUMMARY OF THE INVENTION <EOH>It is one object of the present invention to avoid this disadvantage. This object is achieved according to a first aspect of the invention with an auxiliary part for an auxiliary drive for a trailer such as a caravan, comprising a drum part, which on one free end is provided with a ring gear fitted on its outer circumference, and on the other free end is provided with a bottom having at least three bolt holes lying equally spaced on a pitch circle, said drum being provided with cooling air apertures between the two free ends. This auxiliary part can in particular be combined with an auxiliary drive. The auxiliary part in fact forms a sort of covering drum which leaves the existing brake system intact and is placed in between the existing drum and the wheel. It is held in place by the bolts/nuts used for fixing the wheel on the existing brake drum. Such a covering drum can be used in a simple manner as a universal part, since the clear space between the external diameter of the existing brake drum and the interior of the wheel rim is more or less the same in most wheels, the only variable being the number of bolt holes, the pitch circle of the bolt holes and the central aperture in the drum. These can be provided in a simple manner. According to a further aspect of the present invention, a trailer is provided, comprising a chassis, an axle and an auxiliary drive, said axle being provided with a drum having circumferential gear teeth and a wheel provided on said drum, said gear teeth extending beyond the outer surface of the tyre of said wheel, and also comprising a drive unit provided with a gearwheel, said drive unit being displaceable for engaging with said gear teeth of said drum. According to this aspect, the gear teeth on the drum are taken so far outwards that the auxiliary drive can be moved substantially laterally, in other words in a direction perpendicular to the direction of the axis of the wheel, and in this way can be brought into engagement with the ring gear. The ring gear can be provided either on a brake drum or on the auxiliary part described above, which is used as a covering drum. Such a construction dispenses with an auxiliary shaft of the type described in GB 2,305,408 and simple engagement with the wheel can be provided. Furthermore, guaranteed engagement can be achieved in all circumstances. The drive unit is preferably movable linearly by means of an actuator. The actuator is preferably controlled by the same motor as that driving the gearwheel. The invention will be explained in greater detail below with reference to exemplary embodiments shown in the drawing, in which:
|
BACKGROUND OF THE INVENTION The present invention relates to an auxiliary drive for a trailer. Such an auxiliary drive, for example for a caravan, is generally known in the prior art. It has long been a recognized problem that after uncoupling from a towing vehicle, manoeuvring of heavier trailers in particular constitutes a problem, which can be solved by using relatively small electric motors, which drive the wheels of the trailer. In the prior art the use of drive rollers that are connected to the electric motors and engage the tyre of the wheel is generally proposed. The problem is, however, that considerable pressure forces are necessary to prevent slipping between the drive rollers and the wheels. The fact is that driving of the wheels is required most in difficult circumstances in which such wheels are on soggy ground or the like, when the grip between wheel and drive roller will also be far from optimum. It is felt by some that the pressure of the roller against the tyre can cause damage to the tyre in the long run. Moreover, such a drive is easily damaged. For that reason, British Patent Specification 2,305,408 proposes a drive in which the brake drum of the wheel is provided with a ring gear, and an auxiliary shaft extending parallel to the wheel axle is present. The auxiliary shaft is provided with a gearwheel on both sides, which gearwheel engages with the abovementioned ring gear, on the one hand, and with an auxiliary drive lying inside the chassis, on the other hand. By movement in the axial direction, engagement or disengagement can be achieved. Such a structure avoids the problem of failing contact between roller and tyre, but it has the disadvantage that such a system is not easily universally usable. Moreover, the position of the spring-loaded wheel relative to the chassis constitutes a problem for the positioning of the auxiliary drive. SUMMARY OF THE INVENTION It is one object of the present invention to avoid this disadvantage. This object is achieved according to a first aspect of the invention with an auxiliary part for an auxiliary drive for a trailer such as a caravan, comprising a drum part, which on one free end is provided with a ring gear fitted on its outer circumference, and on the other free end is provided with a bottom having at least three bolt holes lying equally spaced on a pitch circle, said drum being provided with cooling air apertures between the two free ends. This auxiliary part can in particular be combined with an auxiliary drive. The auxiliary part in fact forms a sort of covering drum which leaves the existing brake system intact and is placed in between the existing drum and the wheel. It is held in place by the bolts/nuts used for fixing the wheel on the existing brake drum. Such a covering drum can be used in a simple manner as a universal part, since the clear space between the external diameter of the existing brake drum and the interior of the wheel rim is more or less the same in most wheels, the only variable being the number of bolt holes, the pitch circle of the bolt holes and the central aperture in the drum. These can be provided in a simple manner. According to a further aspect of the present invention, a trailer is provided, comprising a chassis, an axle and an auxiliary drive, said axle being provided with a drum having circumferential gear teeth and a wheel provided on said drum, said gear teeth extending beyond the outer surface of the tyre of said wheel, and also comprising a drive unit provided with a gearwheel, said drive unit being displaceable for engaging with said gear teeth of said drum. According to this aspect, the gear teeth on the drum are taken so far outwards that the auxiliary drive can be moved substantially laterally, in other words in a direction perpendicular to the direction of the axis of the wheel, and in this way can be brought into engagement with the ring gear. The ring gear can be provided either on a brake drum or on the auxiliary part described above, which is used as a covering drum. Such a construction dispenses with an auxiliary shaft of the type described in GB 2,305,408 and simple engagement with the wheel can be provided. Furthermore, guaranteed engagement can be achieved in all circumstances. The drive unit is preferably movable linearly by means of an actuator. The actuator is preferably controlled by the same motor as that driving the gearwheel. The invention will be explained in greater detail below with reference to exemplary embodiments shown in the drawing, in which: DRAWINGS FIG. 1 shows diagrammatically a trailer in which the device according to the present invention is used; FIG. 2 shows in top view a detail of the wheel construction of the trailer shown in FIG. 1, in a first position of the drive unit; FIG. 3 shows a view corresponding to that of FIG. 2 in which the drive unit is in the working position; FIG. 4 shows in perspective the construction shown in FIGS. 2 and 3; FIG. 5 shows a cross section along the line V-V in FIG. 4, FIG. 6 shows in perspective view a further embodiment of the invention in first non-active position; and FIG. 7 shows the device according to FIG. 6 in a second active position. DETAILED DESCRIPTION In FIG. 1 a caravan is indicated by 1. This caravan comprises a chassis 2 with a superstructure 3 and a tow bar 4. It should be understood that the present invention can be used for any trailer which in “normal” circumstances is moved by a towing vehicle and in the case of which its own drive is needed only after uncoupling from the towing vehicle. As can be seen from FIG. 2 and on, the caravan is provided with an axle 7 having a suspension arm 6 hinged to the axle. Wheel 5 is connected to suspension arm 6 and is provided with a tyre 17. It is clear from FIG. 5 that a shaft stud 28, around which a conventional brake drum 19 is rotatably fitted, is provided on suspension arm 6. Details of the brake construction present in the brake drum 19 are not shown. Bolts 25, onto which wheel nuts can be screwed in order to fix the wheel 5, extend from the brake drum 19. According to an aspect of the present invention, an auxiliary part or covering drum 20 is fitted over drum 19. The internal diameter of said covering drum is greater than the external diameter of brake drum 19, while the external diameter of the drum part 22 of the auxiliary part 20 is smaller than the space bounded inside the wheel rim 5. Cooling air apertures 21 are present. The drum part 22 is provided with a ring gear 8 on one end, and is provided with a bottom 23 on the other end, which bottom is provided with bolt holes 24. The pitch and position of the bolt holes correspond to the pitch and position of the bolts 25 in the drum 19, so that covering drum 20 can be slid over drum 19 without any problems. As can be seen from FIGS. 2 and 3, the construction here is such that the ring gear 8 lies outside the plane bounded by the tyre 17 (or wheel 5). This outer boundary is indicated by line 26 in FIG. 2. A drive unit 9 is present, which drive unit is fixed on the chassis 2. On the one hand, the drive unit is fixed at fixing point 15, to which an actuator 11 is connected, which actuator, on the other hand, acts upon a motor 10 which is connected to a transmission 12 and gearwheel 13. This gearwheel 13 can be a conventional gearwheel. The unit, consisting of motor 10, transmission 12 and a gearwheel 13, is fitted on a slide 16 which moves in a guide 14, which is rigidly fixed on the chassis 2. The unit 9 can be fixed on the existing chassis, for example by means of bolts in pre-drilled holes or in newly drilled holes in the chassis. It is also possible to fit a clamp structure around the chassis part concerned, which would obviate the need for drilling holes in the chassis. In addition, it is possible if two units 9 are used on the left and right side of, for example, a caravan, to fit a connecting bar between the two in order to spread the forces as much as possible over the chassis. If this is a universal structure, this connecting bar is preferably adjustable in length (width). According to the present invention, the gearwheel 13 is situated outside the chassis, i.e. in the space between the outer boundary of the chassis and the inner boundary of the wheel/tyre 5/17. This means that the problem that the drive unit has to be placed between cross beams and the like does not arise, and said drive unit can be fitted and maintained, if necessary, in a simple manner. A control system 18, which responds to signals generated by means of a remote control or other control, is present. As will be clear from a comparison of FIGS. 2 and 3, in the travelling position, i.e. the position in which the trailer is being towed, the actuator moves the gearwheel 13 out of engagement with ring gear 8. After the towed vehicle has been uncoupled from the towing vehicle, gearwheel 13 is pressed into engagement with ring gear 8 by moving actuator 11. The presence of gear teeth means that the pressure force is limited or even irrelevant. Only the mutual position of ring gear 8 and gearwheel 13 is important for ensuring complete engagement. The desired movement can be achieved by subsequently driving gearwheel 13. It will be understood that each side of the trailer is provided with such a construction and that possibilities exist for driving the gearwheel 13 concerned at a different speed and/or in a different direction in order to make manoeuvring possible. Furthermore, safety devices may be present to ensure that it is not possible to tow the caravan so long as gearwheel 13 is in engagement with ring gear 8. On the other hand, such a gearwheel engagement can serve as a block to prevent the trailer from being driven away, so that theft is prevented. Furthermore, measures can be taken to prevent said gearwheel 13 from turning before actuator 11 has brought gearwheel 13 into engagement with the ring gear 8. Instead of the covering drum or auxiliary part 20 shown here, it is also possible to provide a drum that functions as a brake drum at the same time and is provided with the ring gear on one end. It is essential here for such a ring gear to be situated outside the plane of the wheel, in other words to be positioned in such a way that putting into or taking out of engagement can be achieved by a simple movement to and fro of the motor 10 with transmission 12 and gearwheel 13. It will be understood that the movement of the gearwheel 13 does not have to be absolutely parallel to a line perpendicular to axis 27, but that can said gearwheel can be placed at a slight angle. In FIGS. 6 and 7 a further embodiment of the device according to the application is shown. The chassis of a caravan is indicated by 32 and a part of a drum 34 is shown being provided with a wheel ring 38 bolted thereto. A motor 40 is slidably arranged on a main slide 46, which can be moved in guide 44 in the direction of the wheel ring 38 in order to have sprocket 43 engage this wheel ring 38. It is noted that the sprocket 43 is made up from pins 33, so that ring gear 38 can be embodied as a ring gear for chains. Through the use of pins the tooth pressure can be lowered and sensitivity for foreign matter is decreased. Displacement of the motor 40 over guide 44 is effected through actuator 41. The motor 40 is not directly connected to the other end of actuator 41 but an auxiliary slide 48 is provided, which is connected to end 49 of main slide 46 through springs 50. Actuator 41 can be displaced over a considerable distance, being larger than the spacing between sprocket 43 and wheel ring 38 as shown in FIG. 6. However, as is clear from FIG. 7, as soon as the sprocket 43 engages the wheel ring 38 at continued movement of actuator 43, auxiliary slide 48 with motor 40 and sprocket 43 will not continue its movement but stay in the contacted position between the wheel ring 38 and sprocket 43. Because of that, the springs 50 will be tensioned (pull). If for example, the engagement between the sprocket 43 and wheel ring 38 is not perfect, Slight rotation of sprocket 43 and the tension in springs 50 will provide perfect engagement between sprocket 43 and wheel ring 38 as yet. Through the use of a pull spring, which is tensioned and not compressed and the relative position of both the slide and the auxiliary slide, a very compact structure can be obtained, which is easily to mount below the floor of a caravan and does not impair the free height of such a vehicle. Furthermore, the length of the structure is very limited. After reading the above description, the person skilled in the art will immediately think of variants which lie within the scope of the appended claims. Combination with all kinds of constructions that are known for independently moving a trailer are possible. Such obvious variants lie within the scope of the appended claims.
|
B
|
B60
|
B60B
|
35
|
16
|
|||
11863902
|
US20090089313A1-20090402
|
DECENTRALIZED RECORD EXPIRY
|
ACCEPTED
|
20090318
|
20090402
|
[]
|
G06F1730
|
["G06F1730"]
|
7783607
|
20070928
|
20100824
|
707
|
662000
|
64848.0
|
ARJOMANDI
|
NOOSHA
|
[{"inventor_name_last": "Cooper", "inventor_name_first": "Brian", "inventor_city": "San Jose", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Weaver", "inventor_name_first": "Daniel", "inventor_city": "Redwood City", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Bigby", "inventor_name_first": "Michael", "inventor_city": "San Jose", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Srivastava", "inventor_name_first": "Utkarsh", "inventor_city": "Fremont", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Bohannon", "inventor_name_first": "Philip L.", "inventor_city": "Cupertino", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Yerneni", "inventor_name_first": "Ramana", "inventor_city": "Cupertino", "inventor_state": "CA", "inventor_country": "US"}]
|
A technique is described that reduces the complexity and resource consumption associated with performing record expiry in a distributed database system. In accordance with the technique, a record is checked to see if it has expired only when it has been accessed for a read or a write. If at the time of a read a record is determined to have expired, then it is not served. If at the time of a write a record is determined to have expired, then the write is treated as an insertion of a new record, and steps are taken to treat the insertion consistently with regard to the previous expired version. A background process is used to delete records that have not been written to or actively deleted by a client after expiration.
|
1. A method for automatically deleting an expired record in a distributed database system comprising a plurality of nodes, wherein each node is configured to manage a respective one of a plurality of databases, the method comprising: receiving a write request for a record at one of the plurality of nodes, wherein the record is part of a partition stored in the database managed by the one of the plurality of nodes; determining whether the record is expired responsive to receiving the write request; determining if an incarnation number associated with the partition exceeds an incarnation number stored in the record responsive to determining that the record is expired; and responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record, generating an updated record based on the write request, wherein generating the updated record comprises replacing the incarnation number stored in the record with the incarnation number associated with the partition; and overwriting the expired record with the updated record. 2. The method of claim 1, wherein generating an updated record based on the write request further comprises setting a sequence number stored in the updated record to an initial value. 3. The method of claim 1, further comprising: sending a message to the other nodes regarding the overwriting of the expired record with the updated record. 4. The method of claim 1, further comprising: responsive to determining that the incarnation number associated with the partition does not exceed the incarnation number stored in the record, deleting the expired record, wherein deleting the expired record comprises sending a message to a remote node to increment an incarnation number associated with a partition stored in the database managed by the remote node, generating an updated record based on the write request, and inserting the updated record. 5. The method of claim 3, wherein generating the updated record comprises: obtaining an incarnation number from a remote node, wherein the incarnation number obtained from the remote node is associated with a partition stored in the database managed by the remote node, and replacing the incarnation number stored in the record with the incarnation number obtained from the remote node. 6. A distributed database system, comprising: a plurality of nodes, wherein the plurality of nodes are interconnected via a communication system; and a plurality of databases, wherein each node in the plurality of nodes is configured to manage a respective one of a plurality of databases; wherein each node in the plurality of nodes is further configured to receive a write request for a record, wherein the record is part of a partition stored in the database managed by the node, to determine whether the record is expired responsive to receiving the write request, to determine if an incarnation number associated with the partition exceeds an incarnation number stored in the record responsive to determining that the record is expired, and, responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record, to generate an updated record based on the write request, wherein generating the updated record comprises replacing the incarnation number stored in the record with the incarnation number associated with the partition, and to overwrite the expired record with the updated record. 7. The system of claim 6, wherein each node in the plurality of nodes is configured to generate an updated record based on the write request by setting a sequence number stored in the updated record to an initial value. 8. The system of claim 6, wherein each node in the plurality of nodes is further configured to send a message to the other nodes via the communication system regarding the overwriting of the expired record with the updated record. 9. The system of claim 6, wherein each node in the plurality of nodes is further configured to, responsive to determining that the incarnation number associated with the partition does not exceed the incarnation number stored in the record, delete the expired record, wherein deleting the expired record comprises sending a message to a remote node to increment an incarnation number associated with a partition stored in the database managed by the remote node, to generate an updated record based on the write request, and to inserting the updated record. 10. The system of claim 9, wherein each node in the plurality of nodes is configured to generate the updated record by obtaining an incarnation number from a remote node, wherein the incarnation number obtained from the remote node is associated with a partition stored in the database managed by the remote node, and replacing the incarnation number stored in the record with the incarnation number obtained from the remote node. 11. A method for automatically deleting an expired record in a distributed database system comprising a plurality of nodes, wherein each node is configured to manage a respective one of a plurality of databases, the method comprising: reading a record at one of the plurality of nodes, wherein the record is part of a partition stored in the database managed by the one of the plurality of nodes; determining whether the record is expired; determining if an incarnation number associated with the partition exceeds an incarnation number stored in the record responsive to determining that the record is expired; and purging the record responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record. 12. The method of claim 11, further comprising: sending a message to the other nodes regarding the purging of the record. 13. The method of claim 11, further comprising: responsive to determining that the incarnation number associated with the partition does not exceed the incarnation number stored in the record, deleting the expired record, wherein deleting the expired record comprises sending a message to a remote node to increment an incarnation number associated with a partition stored in the database managed by the remote node. 14. A distributed database system, comprising: a plurality of nodes, wherein the plurality of nodes are interconnected via a communication system; and a plurality of databases, wherein each node in the plurality of nodes is configured to manage a respective one of a plurality of databases; wherein each node in the plurality of nodes is further configured to read a record, wherein the record is part of a partition stored in the database managed by the node, to determine whether the record is expired, to determine if an incarnation number associated with the partition exceeds an incarnation number stored in the record responsive to determining that the record is expired, and to purge the record responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record. 15. The system of claim 14, wherein each node in the plurality of nodes is further configured to send a message to the other nodes regarding the purging of the record. 16. The system of claim 14, wherein each node in the plurality of nodes is further configured to, responsive to determining that the incarnation number associated with the partition does not exceed the incarnation number stored in the record, delete the expired record, wherein deleting the expired record comprises sending a message to a remote node to increment an incarnation number associated with a partition stored in the database managed by the remote node. 17. A method in a distributed database system for determining which of a first version of a record and a second version of a record is the most recent, comprising: comparing an incarnation number associated with the first version of the record and an incarnation number associated with the second version of the record, wherein each incarnation number represents a version of a partition that existed at the time each record was created; and responsive to determining that one of the first version of the record or the second version of the record has a greater incarnation number, identifying as the most recent the one of the first version of the record or the second version of the record having the greater incarnation number. 18. The method of claim 17, wherein comparing an incarnation number associated with the first version of the record and an incarnation number associated with the second version of the record comprises: reading the first version of the record to obtain the incarnation number associated with the first version of the record; and reading the second version of the record to obtain the incarnation number associated with the second version of the record. 19. The method of claim 17, further comprising: responsive to determining that the first version of the record and the second version of the record have the same incarnation number, comparing a sequence number associated with the first version of the record and a sequence number associated with the second version of the record; and responsive to determining that one of the first version of the record or the second version of the record has a greater sequence number, identifying as the most recent the one of the first version of the record or the second version of the record having the greater sequence number. 20. The method of claim 19, wherein comparing a sequence number associated with the first version of the record and a sequence number associated with the second version of the record comprises: reading the first version of the record to obtain the sequence number associated with the first version of the record; and reading the second version of the record to obtain the sequence number associated with the second version of the record.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention generally relates to the deletion of data from a database. In particular, the invention relates to the automatic deletion of expired data in a distributed database system. 2. Background As used herein the term “record expiry” refers to a system-initiated deletion of a database record. Database records may be set to expire for any number of reasons. For example, the value or relevance of some information decreases over time. Additionally, expiry may be used to remove older data from a system to free up resources to make room for newer data. Various approaches are known for automatically determining when a record in a database has expired and then deleting the record accordingly. By necessity, every approach adds some level of complexity to a database system and consumes some resources of the system. In a distributed database system in which multiple copies of the same record exist in different storage locations, record expiry becomes an even more complex task as the expiration of a record must be carried out in a manner that ensures that different versions of the same record can be properly sequenced after the expiration has occurred. Furthermore, the expiration of a record in a distributed database system consumes even more resources as database operations impacting one copy of a record must be propagated to remotely-stored copies of the same record. What is needed then is a technique that reduces the complexity and resource consumption associated with performing record expiry in a distributed database system.
|
<SOH> BRIEF SUMMARY OF THE INVENTION <EOH>The present invention provides a technique that reduces the complexity and resource consumption associated with performing record expiry in a distributed database system. In particular, a method is described herein for automatically deleting an expired record in a distributed database system that includes a plurality of nodes, wherein each node is configured to manage a respective one of a plurality of databases. In accordance with the method, a write request is received for a record at one of the plurality of nodes. The record is part of a partition stored in the database managed by the one of the plurality of nodes. Responsive to receiving the write request, it is determined whether the record is expired. Responsive to a determination that the record is expired, it is determined if an incarnation number associated with the partition exceeds an incarnation number stored in the record. Responsive to a determination that the incarnation number associated with the partition exceeds the incarnation number stored in the record, an updated record is generated based on the write request, wherein generating the updated record comprises replacing the incarnation number stored in the record with the incarnation number associated with the partition. Further responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record, the expired record is overwritten with the updated record. A distributed database system is also described herein. The system includes a plurality of nodes, wherein the nodes are interconnected via a communication system. The system also includes a plurality of databases, wherein each node in the plurality of nodes is configured to manage a respective one of a plurality of databases. Each node in the plurality of nodes is further configured to receive a write request for a record, wherein the record is part of a partition stored in the database managed by the node, to determine whether the record is expired responsive to receiving the write request, to determine if an incarnation number associated with the partition exceeds an incarnation number stored in the record responsive to determining that the record is expired, and, responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record, to generate an updated record based on the write request, wherein generating the updated record comprises replacing the incarnation number stored in the record with the incarnation number associated with the partition, and to overwrite the expired record with the updated record. An additional method is described herein for automatically deleting an expired record in a distributed database system comprising a plurality of nodes, wherein each node is configured to manage a respective one of a plurality of databases. In accordance with the method, a record is read at one of the plurality of nodes. The record is part of a partition stored in the database managed by the one of the plurality of nodes. It is then determined whether the record is expired. Responsive to a determination that the record is expired, it is determined if an incarnation number associated with the partition exceeds an incarnation number stored in the record. Responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record, the record is purged. An additional distributed database system is also described herein. The system includes a plurality of nodes, wherein the nodes are interconnected via a communication system. The system also includes a plurality of databases, wherein each node in the plurality of nodes is configured to manage a respective one of a plurality of databases. Each node in the plurality of nodes is further configured to read a record, wherein the record is part of a partition stored in the database managed by the node, to determine whether the record is expired, to determine if an incarnation number associated with the partition exceeds an incarnation number stored in the record responsive to determining that the record is expired, and to purge the record responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record. Another method is described herein for determining in a distributed database system which of a first version of a record and a second version of a record is the most recent. In accordance with the method, an incarnation number associated with the first version of the record is compared to an incarnation number associated with the second version of the record. Each incarnation number represents a version of a partition that existed at the time each record was created. Responsive to determining that one of the first version of the record or the second version of the record has a greater incarnation number, the one of the first version of the record or the second version of the record having the greater incarnation number is identified as the most recent. The foregoing method may further include comparing a sequence number associated with the first version of the record and a sequence number associated with the second version of the record responsive to determining that the first version of the record and the second version of the record have the same incarnation number. Then, responsive to determining that one of the first version of the record or the second version of the record has a greater sequence number, the one of the first version of the record or the second version of the record having the greater sequence number is identified as the most recent. Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. It is noted that the invention is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The invention generally relates to the deletion of data from a database. In particular, the invention relates to the automatic deletion of expired data in a distributed database system. 2. Background As used herein the term “record expiry” refers to a system-initiated deletion of a database record. Database records may be set to expire for any number of reasons. For example, the value or relevance of some information decreases over time. Additionally, expiry may be used to remove older data from a system to free up resources to make room for newer data. Various approaches are known for automatically determining when a record in a database has expired and then deleting the record accordingly. By necessity, every approach adds some level of complexity to a database system and consumes some resources of the system. In a distributed database system in which multiple copies of the same record exist in different storage locations, record expiry becomes an even more complex task as the expiration of a record must be carried out in a manner that ensures that different versions of the same record can be properly sequenced after the expiration has occurred. Furthermore, the expiration of a record in a distributed database system consumes even more resources as database operations impacting one copy of a record must be propagated to remotely-stored copies of the same record. What is needed then is a technique that reduces the complexity and resource consumption associated with performing record expiry in a distributed database system. BRIEF SUMMARY OF THE INVENTION The present invention provides a technique that reduces the complexity and resource consumption associated with performing record expiry in a distributed database system. In particular, a method is described herein for automatically deleting an expired record in a distributed database system that includes a plurality of nodes, wherein each node is configured to manage a respective one of a plurality of databases. In accordance with the method, a write request is received for a record at one of the plurality of nodes. The record is part of a partition stored in the database managed by the one of the plurality of nodes. Responsive to receiving the write request, it is determined whether the record is expired. Responsive to a determination that the record is expired, it is determined if an incarnation number associated with the partition exceeds an incarnation number stored in the record. Responsive to a determination that the incarnation number associated with the partition exceeds the incarnation number stored in the record, an updated record is generated based on the write request, wherein generating the updated record comprises replacing the incarnation number stored in the record with the incarnation number associated with the partition. Further responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record, the expired record is overwritten with the updated record. A distributed database system is also described herein. The system includes a plurality of nodes, wherein the nodes are interconnected via a communication system. The system also includes a plurality of databases, wherein each node in the plurality of nodes is configured to manage a respective one of a plurality of databases. Each node in the plurality of nodes is further configured to receive a write request for a record, wherein the record is part of a partition stored in the database managed by the node, to determine whether the record is expired responsive to receiving the write request, to determine if an incarnation number associated with the partition exceeds an incarnation number stored in the record responsive to determining that the record is expired, and, responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record, to generate an updated record based on the write request, wherein generating the updated record comprises replacing the incarnation number stored in the record with the incarnation number associated with the partition, and to overwrite the expired record with the updated record. An additional method is described herein for automatically deleting an expired record in a distributed database system comprising a plurality of nodes, wherein each node is configured to manage a respective one of a plurality of databases. In accordance with the method, a record is read at one of the plurality of nodes. The record is part of a partition stored in the database managed by the one of the plurality of nodes. It is then determined whether the record is expired. Responsive to a determination that the record is expired, it is determined if an incarnation number associated with the partition exceeds an incarnation number stored in the record. Responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record, the record is purged. An additional distributed database system is also described herein. The system includes a plurality of nodes, wherein the nodes are interconnected via a communication system. The system also includes a plurality of databases, wherein each node in the plurality of nodes is configured to manage a respective one of a plurality of databases. Each node in the plurality of nodes is further configured to read a record, wherein the record is part of a partition stored in the database managed by the node, to determine whether the record is expired, to determine if an incarnation number associated with the partition exceeds an incarnation number stored in the record responsive to determining that the record is expired, and to purge the record responsive to determining that the incarnation number associated with the partition exceeds the incarnation number stored in the record. Another method is described herein for determining in a distributed database system which of a first version of a record and a second version of a record is the most recent. In accordance with the method, an incarnation number associated with the first version of the record is compared to an incarnation number associated with the second version of the record. Each incarnation number represents a version of a partition that existed at the time each record was created. Responsive to determining that one of the first version of the record or the second version of the record has a greater incarnation number, the one of the first version of the record or the second version of the record having the greater incarnation number is identified as the most recent. The foregoing method may further include comparing a sequence number associated with the first version of the record and a sequence number associated with the second version of the record responsive to determining that the first version of the record and the second version of the record have the same incarnation number. Then, responsive to determining that one of the first version of the record or the second version of the record has a greater sequence number, the one of the first version of the record or the second version of the record having the greater sequence number is identified as the most recent. Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. It is noted that the invention is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the relevant art(s) to make and use the invention. FIG. 1 is a block diagram of an example distributed database system in which an embodiment of the present invention may operate. FIG. 2 depicts a simple example of horizontal partitioning. FIG. 3 depicts a simple example of replication. FIG. 4 illustrates one implementation of a distributed database system in which a node comprises a plurality of servers and in which each server is connected to a corresponding local storage system or device that stores a different partition replica. FIG. 5 shows components of a distributed database system that are involved in updating a record when a client update request is first received by a node that is designated the record master. FIG. 6 shows components of a distributed database system that are involved in updating a record when a client update request is first received by a node that is not designated the record master. FIG. 7 depicts a format of an example database record that includes a composite version number in accordance with an embodiment of the present invention. FIG. 8 illustrates a flowchart of a method for setting and/or updating incarnation and sequence numbers in accordance with an embodiment of the present invention. FIG. 9 illustrates a flowchart of a method by which a node in a distributed database system uses record-level incarnation numbers and sequence numbers to determine which of two versions of the same record is most recent in accordance with an embodiment of the present invention. FIG. 10 depicts steps relating to record expiry that are performed by a node within distributed database system when performing a read operation in accordance with an embodiment of the present invention. FIG. 11 depicts steps relating to record expiry that are performed by a node within a distributed database system when performing a write (or update) operation in accordance with an embodiment of the present invention. FIG. 12 illustrates a flowchart of a garbage collection process implemented by nodes within a distributed database system in accordance with an embodiment of the present invention. FIG. 13 illustrates an example processor-based computer system that may be used to implement the present invention. The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number. DETAILED DESCRIPTION OF THE INVENTION A. Example Operating Environment FIG. 1 is a high-level block diagram of an example distributed database system 100 in which an embodiment of the present invention may operate. System 100 is described herein by way of example only and is not intended to limit the present invention. Based on the teachings provided herein, persons skilled in the relevant art(s) will understand that the present invention may be implemented in a distributed database system having a different architecture than that of system 100 or in a distributed database system that is configured to function in a different manner than that of system 100. As shown in FIG. 1, distributed database system 100 includes a plurality of nodes 102a, 102b, 102c and 102d. Although only four nodes are shown in FIG. 1, persons skilled in the relevant art(s) will appreciate that, depending on the size and organization of distributed database system 100, the system may include any number of nodes. Nodes 102a, 102b, 102c and 102d are communicatively interconnected via a communication system 106. In the following description, two components of system 100 will be termed “local” with respect to one another if communication between them does not require a transfer of information between any of nodes 102a, 102b, 102c and 102d. Otherwise, the two components will be termed “remote.” In one implementation of distributed database system 100, the nodes are geographically dispersed. However, this need not be the case. Thus, as used herein, the terms “local” and “remote” are not intended to suggest that the nodes must be geographically dispersed. Each node is configured to provide database services to a different plurality of local clients. Thus, for example, node 102a is configured to provide database services to a plurality of local clients 108a, node 102b is configured to provide database services to a plurality of local clients 108b, node 102c is configured to provide database services to a plurality of local clients 108c, and node 102d is configured to provide database services to a plurality of local clients 108d. To provide database services, each node is communicatively connected to a local database. In particular, node 102a is connected to a local database 104a, node 102b is connected to a local database 104b, node 102c is connected to a local database 104c, and node 102d is connected to a local database 104d. Each local database includes a copy of all or a portion of the total database records within distributed database system 100. Thus, copies of the data records of system 100 are distributed across the multiple databases 102a, 102b, 102c and 102d. In distributed database system 100, the database records are divided into partitions and replicas of the partitions are stored in each local database 104a, 104b, 104c and 104d. Although the techniques of partitioning and replicating are well-known to persons skilled in the relevant art(s), a brief description of these techniques as applied to the records of distributed database system 100 will now be provided. As noted above, in distributed database system 100, the database records are divided into partitions. Each partition comprises a distinct and independent portion of the database. Taken together, the partitions constitute a copy of the entire logical database. In distributed database system 100, the manner in which the database records are divided is termed “horizontal partitioning.” In horizontal partitioning, individual rows of a database are placed into different tables, wherein each row represents a database record. This is in contrast to “vertical partitioning,” which involves removing columns (or fields) to obtain tables having fewer columns, and then creating new tables to store the remaining columns. A simple example of horizontal partitioning is illustrated in FIG. 2. As shown in FIG. 2, a database 202 includes a plurality of records, wherein each record comprises a unique key 212 and associated information 214. Key 212 is used to uniquely identify each record and serves as an index for locating each record within database 202. Information 214 represents any type of information that may be stored in a database in association with a key and may comprise, for example, one or more information fields. Through the application of horizontal partitioning, database 202 is split into a first partition 204 and a second partition 206, wherein first partition 204 includes the first five records of database 202 and second partition 206 includes the last five records. Taken together, first partition 204 and second partition 206 comprise a complete logical copy of database 202. Of course, this is just one example of horizontal partitioning. Persons skilled in the relevant art(s) will understand that by using horizontal partitioning, a single database may be divided into any number of partitions, and that partitions may include any number of records. Horizontal partitioning may be used for a variety of reasons. For example, a large database may be rendered more manageable by dividing it into separate partitions. Furthermore, in some systems, different partitions can be assigned to different storage systems or devices to parallelize and improve throughput of network operations. Additionally, partitioning may facilitate load balancing by allowing one or more partitions to be moved from one storage system or device to another. As also noted above, in addition to using partitions, distributed database system 100 also uses replication. In replication, multiple copies or instances of a database or its partitions are created, and the multiple copies are managed by different nodes. Replication can also improve the throughput of network operations. For example, one benefit of replication is that it permits clients at disparate geographic locations to each access a local replica of the same data, thereby increasing the speed and decreasing the expense associated with database accesses by each client. Replication can also be used for load balancing purposes. A simple example of replication is illustrated in FIG. 3. As shown in FIG. 3, a single logical database 302 comprises four horizontal partitions—namely, Partition A, Partition B, Partition C and Partition D. Using replication, the single logical database 302 is copied to generate four logical databases replicas—namely, logical database 304, logical database 306, logical database 308 and logical database 310. Each of the logical database replicas includes a copy of the same partitions included in the original logical database 302. In this example, each of the logical database replicas is used to serve clients in a different geographic region and each replica's partitions are named accordingly. For example, logical database 304 serves clients in a geographic region denoted “north” and its partitions are accordingly named Partition A North, Partition B North, Partition C North and Partition D North. This is just one example of replication. Persons skilled in the relevant art(s) will understand that by using replication, any number of partition replicas may be created. In one implementation of distributed database system 100, each node comprises a plurality of servers, and each of the servers is responsible for managing a different partition replica that is stored on a respective local storage system or device. This is depicted in FIG. 4, which illustrates an implementation of system 100 in which node 102a comprises four servers—namely, server A, server B, server C and server D. Each of these servers is connected to a corresponding local storage system or device which stores a particular partition replica. In particular, as shown in FIG. 4, server A is connected to a local storage system or device that stores local partition A, server B is connected to a local storage system or device that stores local partition B, server C is connected to a local storage system or device that stores local partition C and server D is connected to a local storage system or device that stores local partition D. Taken together, local partitions A, B, C and D may comprise a complete replica or copy of the data records of system 100. Also, taken together, the storage systems or devices used to store these local partitions comprise local database 104a. Because distributed database system 100 stores a separate replica of the same set of partitions in each of local databases 104a, 104b, 104c and 104d, the system is configured to use certain protocols to ensure that changes made to a database record in one partition replica are propagated to copies of the same record that exist in other replicas of the same partition. This is necessary to ensure consistency among the multiple partition replicas. For example, because multiple copies of a single record can exist in different partition replicas, distributed database system 100 is configured to designate only one node a “record master” for each record. The record master always manages the most recent version of the record. Distributed database system 100 is configured to ensure that any update of a record is performed by the record master. The update is then propagated from the record master to all the other nodes using a message broker or other notification system or protocol. By way of illustration, FIG. 5 depicts components of distributed database system 100 that are involved in updating a record when the client update request is first received by the record master. As shown in FIG. 5, a client 502 (which is intended to represent one of the plurality of clients 108a shown in FIG. 1) requests an update by sending a request to node 102a. Because node 102a is the record master, it can immediately perform the update and then send a confirmation message back to client 502. The update can then be propagated from node 102a to the other nodes shown in FIG. 1 for application to other copies of the same record residing in remote databases. This propagation can occur sometime after the initial update has occurred. Consequently, the propagation of the update does not in any way impact the speed with which the initial update occurs. Also, the propagation can be scheduled to occur at a time that least interferes with the operation of distributed database system 100, such as at a time when communication system 106 has more bandwidth than it needs to satisfy pending client requests. Alternatively, node 102a can initiate the propagation of the update to the other nodes shown in FIG. 1 prior to performing the update locally. This approach is beneficial in that it ensures that the update will be published to the other nodes even if node 102a should fail during the performance of the local update. Should node 102a fail, a process is implemented that ensures that node 102a will implement the pending update locally after node 102a is brought back online. In contrast to the example shown in FIG. 5, FIG. 6 illustrates components of distributed database system 100 that are involved in updating a record when the client update request is first received by a node that is not the record master. As shown in FIG. 6, client 502 requests an update by sending a request to node 102a. Because node 102a is not the record master, node 102a must forward the request via communication system 106 to the record master. In this example, the record master is node 104c. Thus, node 102a forwards the request to node 102c. Node 102c performs the update and then sends a confirmation message back to node 102a for forwarding on to client 402. The update is also propagated to the other nodes shown in FIG. 1 for application to other copies of the same record residing in remote databases. Depending upon how distributed database system 100 is configured, in addition to forwarding the request to node 102c and forwarding the confirmation to client 502, node 102a may also need to perform a database operation to determine whether it is, in fact, the record master for the record to be updated. This is because in one implementation of distributed database system 100, whether a node is a record master for a particular record is designated by an indicator that is stored within the record itself. This is illustrated in example database record 700 of FIG. 7, which includes a record master indicator 706. After determining that it is not the record master, node 102a may also need to engage in communication with each of nodes 102b, 102c and 102d to determine which one of those nodes is the record master. As can be seen from FIG. 5 and FIG. 6, then, performing an update when the record master first receives the update request consumes less time and system resources than when a node that is not the record master first receives the update request. Thus, distributed database system 100 is configured to designate a node as a record master for a record if the record in question is deemed most likely to be updated by clients that are local with respect to the node. The manner in which distributed database system 100 performs this designation is beyond the scope of this application and therefore will not be described further herein. In distributed database system 100, insertions and deletions may be thought of as special kinds of updates. As will be described in more detail herein, in one mode of operation, an insertion request must be forwarded to a node that is designated the partition master and the partition master inserts the record if it is determined that no other record exists that has the same key. As will also be described in more detail herein, deletions are performed using a multi-step process. First the record master hides but does not delete the relevant record. Then, the deletion request is forwarded to a partition master. The partition master deletes the local copy of the relevant record and then publishes both the deletion and a new incarnation number to the remote nodes. Only then does the record master purge the relevant record. In contrast to a client request to update a record, which must always be performed by the record master, requests to read a record need not always be performed by the record master. In other words, distributed database system 100 allows read requests to be satisfied by nodes that are not the record master by accessing a record stored in a local database, even if that record is not the most recent copy of that record. This allows distributed database system 100 to optionally present out-of-date data to a user in the interest of decreasing transaction time and conserving system resources. B. Use of Version Numbers in Accordance with an Embodiment of the Present Invention In distributed database system 100, each insertion, deletion or update of a record may be thought of as producing a new “logical version” of the record. The term “logical” is used in this context because distributed database system 100 is not configured to actually maintain a copy of each version of the record, but rather is configured to maintain only the most recent version. The term “logical” is also used in this context because a deleted record may be considered to be another version of a record even though the record no longer exists after the deletion. Certain operations performed by database management system 100 require the system to determine which version of a particular record is the most recent. For example, if a series of updates are performed on a record by the record master, a remote node may subsequently receive multiple versions of the record propagated from the record master. The versions may not necessarily be received in an order that corresponds to the order in which the updates were performed by the record master. For example, if communication system 106 is a packet network, network latency may cause one version of the record representing a more recent update to arrive before another version of the record representing an older update. To deal with this, the node receiving the multiple versions of the record must be capable of determining which version is truly the most recent. In order to make this determination, distributed database system 100 maintains a version number in association with each database record. The version number is stored as a part of each record. In accordance with an embodiment of the present invention, the version number comprises two components: a record-level incarnation number, which is a copy of a partition-level incarnation number that is incremented whenever a record in a partition is deleted (and possibly more frequently), and a record-level sequence number, which is incremented whenever a record is updated. As will be described in more detail below, the composite nature of the version number allows distributed database system 100 to properly sequence different versions of a given record. FIG. 7 depicts a format 700 of an example database record that includes a version number in accordance with an embodiment of the present invention. As shown in FIG. 7, in addition to a key 702, a record master indicator 706, and information fields 708, the database record also includes a version number 704, which consists of a record-level incarnation number 710 and a sequence number 712. As noted above, in distributed database system 100, a partition-level incarnation number is maintained. This means that each node is configured to maintain an incarnation number for each locally-stored database partition. However, because distributed database system 100 stores multiple replicas of each partition, the system is also configured to designate only one of the nodes a “partition master.” The partition master is the node that that stores the only authoritative copy of the current partition-level incarnation number for a given partition. All other nodes must obtain their partition-level incarnation number for that partition from the partition master. Furthermore, as will be described in more detail below, all deletions performed by a record master must be reported to the partition master and all insertions performed by a record master must be performed, in part, by obtaining a partition-level incarnation number from the partition master. FIG. 8 illustrates a flowchart 800 of a method for setting and/or updating incarnation and sequence numbers in accordance with an embodiment of the present invention. In particular, flowchart 800 depicts a method by which an embodiment of the present invention sets and/or updates partition-level incarnation numbers as well as record-level incarnation numbers and sequence numbers. In one embodiment, the method of flowchart 800 is performed by each node in distributed database system 100 whenever the node performs a database operation upon a record for which the node is the designated record master. Generally speaking, database operations that are performed by a node upon a record for which the node is not designated record master will not cause a modification of a partition-level incarnation number, a record-level incarnation number, or a sequence number. As shown in FIG. 8, the method of flowchart 800 begins at step 802, in which the type of database operation that has been performed by the record master is determined. As shown at decision step 804, if the database operation is an update, then the sequence number associated with the record is increased as shown at step 810. This increased sequence number will then be reflected in all updates propagated from the record master to other nodes for updating remotely-stored copies of the same record. After step 810, processing ends as shown at step 812. If the database operation is not an update, then processing proceeds from decision step 804 to decision step 806. As shown at decision step 806, if the database operation is a delete, then the partition-level incarnation number maintained by the partition master is increased as shown at step 814. If the node at which the delete occurred is the partition master, then this operation can be handled locally. However, if the node at which the delete occurred is not the partition master, then this operation must be performed by a remote node. As shown at step 816, after the incarnation number is increased in step 814, the deletion and the updated incarnation number are then published to all remote nodes. Each remote node then purges the relevant record and also updates its own partition-level incarnation number to match the updated authoritative version of the partition-level incarnation number from the partition master. After step 816, processing ends as shown at step 812. If the database operation is not a delete, then processing proceeds from decision step 806 to decision step 808. As shown at decision step 808, if the database operation is an insert, then the partition-level incarnation number is obtained from the partition master as shown at step 818. If the node at which the insert occurred is the partition master, then this operation can be handled locally. However, if the node at which the insert occurred is not the partition master, then this operation must be performed by a remote node. At shown at step 820, if the partition master is a remote node, then the node at which the insert occurred updates its own partition-level incarnation number to match the obtained authoritative version of the partition-level incarnation number from the partition master. At step 822, the node at which the insert occurred sets the record-level incarnation number of the newly-inserted record to match the obtained authoritative version of the partition-level incarnation number from the partition master. At step 824, the node at which the insert occurred sets the sequence number of the newly-inserted record to an initial value, which in one embodiment is the lowest value that can be held by the sequence number. If at decision step 808 it is determined that the database operation is not an insert, then processing ends as shown at step 812. FIG. 9 illustrates a flowchart 900 of a method by which a node in distributed database system 100 uses record-level incarnation numbers and sequence numbers to determine which of two versions of the same record is most recent. The method of flowchart 900 may be used by a node, for example, when it receives two different versions of the same record from a remote record master following the performance of a series of updates to the record by the record master. As shown in FIG. 9, the method of flowchart 900 begins at step 902 in which the node compares the two record-level incarnation numbers respectively associated with the two version of the record. At decision step 904, it is then determined whether the record-level incarnation numbers compared in step 902 are the same. If they are not the same, then as shown in step 906 the version of the record with the larger record-level incarnation number is deemed the most recent and processing ends at step 922. However, if it is determined at decision step 904 that the record-level incarnation numbers compared in step 902 are the same, then processing proceeds to step 908, in which the node compares the two sequence numbers respectively associated with the two versions of the record. At decision step 910, it is then determined whether the sequence numbers compared in step 908 are the same. If they are not the same, then as shown in step 912 the version of the record with the larger sequence number is deemed the most recent and processing ends at step 922. However, if it is determined at decision step 910 that the sequence numbers compared in step 908 are the same, then processing proceeds to step 914, in which the node compares the contents of each version of the record. At decision step 916, it is then determined whether the contents of each version of the record are the same. If the contents are the same, then the versions are identical and either can be deemed the most recent as shown at step 920. Also, during this step, a warning is automatically logged. If the contents are not the same, then two different versions of the same record have the same version number. In this case, the version of the record received first by the node is deemed the most recent and the version received second is rejected as shown at step 918. Also, during this step, a critical error is automatically logged that invites or requires human attention. After the execution of either step 918 or 920, processing ends at step 922. As can be seen from the foregoing description, distributed database system 100 maintains and uses incarnation numbers and sequence numbers to sequence different versions of the same record. If the system used only a sequence number to perform this function, then a problem might result when a record was deleted and then a record with the same key was inserted. The deletion of the record would cause the sequence number associated with the record to be lost. As a result, if a record having the same key was inserted, there would be no way to ensure that the sequence number associated with the newly-inserted record was distinct from other versions of the deleted record that might still reside in one or more storage locations in distributed database system 100. The method of flowchart 800 addresses this issue by assigning a version number to the newly-inserted record that is distinct from any version number associated with a previous version of the record. In particular, by incrementing the incarnation number of a partition on any delete from the partition, and then setting the record-level incarnation number of the newly-inserted record equal to the incremented partition-level incarnation number, the method of flowchart 800 ensures that if a record is deleted and then a record with the same key is inserted, the newly-inserted record will have a distinct version number as compared to the deleted record. This is because the incarnation number portion of the version number will by necessity be distinct. This approach is superior to that used by conventional distributed database systems that maintain “tombstone” records to address the same problem. As will be appreciated by persons skilled in the relevant art(s), in such conventional systems, after deletion of a record, a stub record is maintained to represent the deleted record, wherein the stub record includes a version number associated with the deleted record. The creation, maintenance and expiration of such tombstone records add a significant amount of complexity and expense to the distributed database system. An embodiment of the present invention avoids the use of such tombstone records by essentially aggregating the same information into a partition-level incarnation number. However, maintaining the partition-level incarnation number can still require an expensive operation. As shown above in flowchart 800 of FIG. 8, all insert and delete operations performed by a record master require accessing the partition master. If the record master is not also the partition master, then this operation must be performed by a remote node. This remote access is costly in terms of the time and bandwidth. For distributed database systems with large partitions, it is virtually impossible to ensure that the record master and the partition master will always be the same node. Therefore, in such systems, there is a reasonable likelihood that a record deletion or insertion will require the performance of this expensive operation. C. Decentralized Record Expiry in Accordance with an Embodiment of the Present Invention As used herein the term “record expiry” refers to a system-initiated deletion of a database record. Database records may be set to expire for any number of reasons. For example, the value or relevance of some information decreases over time. Additionally, expiry may be used to remove older data from a system to free up resources to make room for newer data. In distributed database system 100, expiry is logically a delete, with the only difference being that it is initiated by the system rather than by a client. Thus, when a record expires, the record master must ensure that the incarnation number maintained at the partition master is increased. One straightforward way to implement an expiration in distributed database system 100 is for each node to determine when a record for which it is designated record master has expired and to perform the following steps responsive to determining that the record has expired: (1) stop accepting updates to the record, (2) access the partition master to increment the partition-level incarnation number, and then (3) purge the record. However, this solution is expensive for at least two reasons. First, it requires a mechanism that triggers an alert to the record master when the record has expired. Second, in any case where the record master is not also the partition master, the solution requires a remote access to the partition master, which as described above, can be expensive. In a large-scale distributed database system with millions or billions of records, the necessary logic for implementing the trigger and the bandwidth cost for remote accesses to the partition master can be prohibitive. An embodiment of the present invention utilizes a different approach. In accordance with this embodiment, database records are not actively expired. Rather, a record is checked to see if it has expired only when it has been accessed for a read or a write. If at the time of a read a record is determined to have expired, then distributed database system 100 does not serve it, instead acting as if it had been deleted. If at the time of a write a record is determined to have expired, then the write is treated as an insertion of a new record, and steps are taken to treat the insertion consistently with regard to the previous expired version. This approach to expiry will now be more fully described in reference to flowchart 1000 of FIG. 10 and flowchart 1100 of FIG. 11. In particular, flowchart 1000 of FIG. 10 depicts steps that are performed by a node within distributed database system 100 when performing a read operation while flowchart 1100 of FIG. 11 depicts steps that are performed by a node within distributed database system when performing a write (or update) operation. As shown in FIG. 10, the method of flowchart 1000 begins at step 1002, in which a client request to read a record is received. At decision step 1004, a determination is made as to whether the requested record has expired. Determining whether the record has expired may involve determining whether an expiration period associated with the record has passed or whether a current date and/or time is later than an expiration date and/or time associated with the record. However, these examples are not intended to be limiting and other methods may be used to determine whether the record has expired as will be appreciated by persons skilled in the relevant art(s). If the record has not expired, then the read request is handled in a normal fashion as shown at step 1006. However, if the record has expired, then the record is not served to the client. Thus, the read request is effectively treating as if the record has been deleted. This is shown at step 1008. After the performance of either step 1006 or step 1008, processing ends as shown at step 1010. As shown in FIG. 11, the method of flowchart 1100 begins at step 1102, in which a client request to write a record is received by the record master. As noted above, all write requests are handled by the record master. At step 1104, a determination is made as to whether the requested record has expired. As noted above, determining whether the record has expired may involve determining whether an expiration period associated with the record has passed or whether a current date and/or time is later than an expiration date and/or time associated with the record. However, these examples are not intended to be limiting and other methods may be used to determine whether the record has expired as will be appreciated by persons skilled in the relevant art(s). If the record has not expired, then the write request is handled in a normal fashion as shown at step 1118 and then processing ends as shown at step 1120. However, if the record has expired, then the write is treated as an insertion of a new record, and steps are taken to treat the insertion consistently with regard to the previous expired version. These steps begin with decision step 1106. At decision step 1106, the record master determines whether the local partition-level incarnation number has advanced beyond the incarnation number in the expired record. If it has not (i.e., if the local partition-level incarnation number is less than or equal to the incarnation number in the expired record), then the record master first initiates a normal delete of the expired record as shown at step 1108. As described above in reference to flowchart 800 of FIG. 8, this deletion requires accessing the partition master to update the authoritative partition-level incarnation number. After step 1108, the record master next initiates a normal insertion of the updated record as shown at step 1110. As also described above in reference to flowchart 800 of FIG. 8, this insertion requires accessing the partition master to obtain the authoritative partition-level incarnation number. The performance of these steps ensures that the inserted record will have a distinct version number from the expired record, as described in detail above. However, if the record master is not also the partition master, than a costly remote access must be performed to carry out each of these steps. After the performance of step 1110, processing ends as shown at step 1120. If, however, at decision step 1106, the record master determines that the local partition-level incarnation number has advanced beyond the incarnation number in the expired record (i.e., if the local partition-level incarnation number is greater than the incarnation number in the expired record), then the record master locally generates a new version number for the updated version of the record in the manner shown at step 1112. In particular, the new version number is created by combining the local partition-level incarnation number with a sequence number, wherein the sequence number is set to an initial value. In one embodiment the initial value is the lowest value that can be held by the sequence number. This value may be, for example, zero. Then, at step 1114, the record master overwrites the expired version of the record with the updated version of the record. At step 1116, the record master propagates this change to other nodes using a message broker or other notification system or protocol. After step 1116, processing ends as shown at step 1120. Note that due to the publication of increments to the authoritative version of the partition-level incarnation number by the partition master (as described above in reference to step 816 of FIG. 8), the local partition-level incarnation number should never be less than the incarnation number in the expired record. Thus, the detection of such a condition during step 1106 would indicate a programming error or some other error condition within system 100. Performing steps 1112, 1114 and 1116 as described above avoids the remote accesses to the partition master that need to be performed during steps 1108 and 1110 in cases where the record master is not the partition master. These remote accesses can be avoided because the test implemented by decision step 1106 ensures that the version number generated locally for the updated record in step 1112 will be distinct from the version number associated with the expired record. Note than in some cases the local partition-level incarnation number may be less than the authoritative partition-level incarnation number maintained by the partition master. However, this is not a problem so long as the local partition-level incarnation number exceeds the record-level incarnation number in the version number of the expired record. In a distributed database in which each partition includes a very large number of records, it is highly likely that the local partition-level incarnation number will exceed the record-level incarnation number in the version number of the expired record. This is because it is highly likely that at least one other record in the partition will have been recently deleted or expired, thereby causing the local partition-level incarnation number to increase beyond the record-level incarnation number. Thus, it is anticipated that in a distributed database system with large partitions, expiration upon writes can be handled using steps 1112, 1114 and 1116 (which avoid remote accesses) rather than steps 1108 and 1110 (which may require remote accesses) in the vast majority of cases. In distributed database system 100, some records may expire but never be written to or actively deleted by a client after expiration. Consequently, in an embodiment of the present invention, each node implements a “garbage collection” process that augments the previously-described processes. Each node runs the garbage collection process periodically and in the background to reclaim storage space. For efficiency, the process may be run only when utilization of node resources for servicing client requests is low. As will be described in more detail below, the garbage collection process iterates over all locally-stored records. If a record is expired and the node is the record master, expiry is initiated in a like manner to that described in steps 1114 and 1116 of FIG. 11, except that purging replaces the overwriting in step 1114. The partition master only needs to be contacted if the local partition-level incarnation number has not advanced beyond that in the expired record's version number. FIG. 12 provides a flowchart 1200 of such a process. As shown in FIG. 12, the method of flowchart 1200 begins at step 1202, in which the node reads a record from its local database. At decision step 1204, the node determines if it is the record master for that record. If the node is not the record master, then control flows to decision step 1216. At decision step 1216, the node determines if there are any more records in the local database. If there are more records in the local database, then control returns to step 1202 and the next record is read from the local database. If there are no more records in the local database, then the process ends as shown at step 1218. If, at decision step 1204, the node determines that it is the record master for the record that was read in step 1202, then control flows to decision step 1206. At decision step 1206, the node determines whether the record that was read in step 1202 has expired. As noted above, determining whether the record has expired may involve determining whether an expiration period associated with the record has passed or whether a current date and/or time is later than an expiration date and/or time associated with the record. However, these examples are not intended to be limiting and other methods may be used to determine whether the record has expired as will be appreciated by persons skilled in the relevant art(s). If the record has not expired, then control flows to decision step 1216, in which the node determines if there are any more records in the local database. If there are more records in the local database, then control returns to step 1202 and the next record is read from the local database. If there are no more records in the local database, then the process ends as shown at step 1218. If it is determined at decision step 1206 that the record that was read in step 1202 has expired, then control flows to decision step 1208. At decision step 1208, the node determines whether the local partition-level incarnation number has advanced beyond the incarnation number in the expired record. If it has not (i.e., if the local partition-level incarnation number is less than or equal to the incarnation number in the expired record), then the node initiates a normal delete of the expired record as shown at step 1210. As described above in reference to flowchart 800 of FIG. 8, this deletion requires accessing the partition master to update the authoritative partition-level incarnation number. However, if the node performing the garbage collection process is not also the partition master, than a costly remote access must be performed to carry out this step. After the performance of step 1210, control flows to decision step 1216, in which the node determines if there are any more records in the local database. If there are more records in the local database, then control returns to step 1202 and the next record is read from the local database. If there are no more records in the local database, then the process ends as shown at step 1218. If it is determined at decision step 1208 that the local partition-level incarnation number has advanced beyond the incarnation number in the expired record (i.e., if the local partition-level incarnation number is greater than the incarnation number in the expired record), then the node purges the expired record as shown at step 1212. No contact with the partition master need be made. At step 1214, the node propagates this change to other nodes using a message broker or other notification system or protocol. After step 1214, control flows to decision step 1216, in which the node determines if there are any more records in the local database. If there are more records in the local database, then control returns to step 1202 and the next record is read from the local database. If there are no more records in the local database, then the process ends as shown at step 1218. Performing steps 1212 and 1214 as described above avoids the remote access to the partition master that needs to be performed during step 1210 in cases where the record master is not the partition master. The remote access can be avoided because the test implemented by decision step 1208 ensures that any record inserted after the purging of the expired record that has the same key as the expired record will be assigned a version number that is distinct from the version number associated with the expired record. As noted above, in a distributed database in which each partition includes a very large number of records, it is highly likely that the local partition-level incarnation number will exceed the record-level incarnation number in the version number of the expired record. This is because it is highly likely that at least one other record in the partition will have been recently deleted or expired, thereby causing the local partition-level incarnation number to increase beyond the record-level incarnation number. Thus, it is anticipated that in a distributed database system with large partitions, expiry based on a garbage collection process can be handled using steps 1212 and 1214 (which avoid remote accesses) rather than step 1210 (which may require a remote access) in the vast majority of cases. It should be noted that in an alternate embodiment, the garbage collection process can use a normal delete (as described above in reference to step 1210) to delete expired records in every case. Although this is less optimal than the method described above in reference to flowchart 1200 in terms of conserving time and system bandwidth, it is a simpler approach and may be deemed acceptable in some cases. For example, since the garbage collection process is run in the background instead of as a part of a client-initiated process, it may be that a certain amount of latency is tolerable. Also, since the garbage collection process may be run during periods of time when system resource utilization is low, it may also be that a certain amount of extra resource consumption is tolerable. D. Example Computer System Implementation Many of the elements of distributed database system 100 as well as many of the steps of flowcharts 800, 900, 1000, 1100 and 1200 may be implemented using any well-known processor-based computer system. An example of such a computer system 1300 is depicted in FIG. 13. As shown in FIG. 13, computer system 1300 includes a processing unit 1304 that includes one or more processors. Processor unit 1304 is connected to a communication infrastructure 1302, which may comprise, for example, a bus or a network. Computer system 1300 also includes a main memory 1306, preferably random access memory (RAM), and may also include a secondary memory 1320. Secondary memory 1320 may include, for example, a hard disk drive 1322, a removable storage drive 1324, and/or a memory stick. Removable storage drive 1324 may comprise a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, or the like. Removable storage drive 1324 reads from and/or writes to a removable storage unit 1328 in a well-known manner. Removable storage unit 1328 may comprise a floppy disk, magnetic tape, optical disk, or the like, which is read by and written to by removable storage drive 1324. As will be appreciated by persons skilled in the relevant art(s), removable storage unit 1328 includes a computer usable storage medium having stored therein computer software and/or data. In alternative implementations, secondary memory 1320 may include other similar means for allowing computer programs or other instructions to be loaded into computer system 1300. Such means may include, for example, a removable storage unit 1330 and an interface 1326. Examples of such means may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units 1330 and interfaces 1326 which allow software and data to be transferred from the removable storage unit 1330 to computer system 1300. Computer system 1300 may also include a communications interface 1340. Communications interface 1340 allows software and data to be transferred between computer system 1300 and external devices. Examples of communications interface 1340 may include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, or the like. Software and data transferred via communications interface 1340 are in the form of signals which may be electronic, electromagnetic, optical, or other signals capable of being received by communications interface 1340. These signals are provided to communications interface 1340 via a communications path 1342. Communications path 1342 carries signals and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link and other communications channels. As used herein, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage unit 1328, removable storage unit 1330, a hard disk installed in hard disk drive 1322, and signals received by communications interface 1340. Computer program medium and computer useable medium can also refer to memories, such as main memory 1306 and secondary memory 1320, which can be semiconductor devices (e.g., DRAMs, etc.). These computer program products are means for providing software to computer system 1300. Computer programs (also called computer control logic, programming logic, or logic) are stored in main memory 1306 and/or secondary memory 1320. Computer programs may also be received via communications interface 1340. Such computer programs, when executed, enable the computer system 1300 to implement features of the present invention as discussed herein. Accordingly, such computer programs represent controllers of the computer system 1300. Where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system 1300 using removable storage drive 1324, interface 1326, or communications interface 1340. The invention is also directed to computer program products comprising software stored on any computer useable medium. Such software, when executed in one or more data processing devices, causes a data processing device(s) to operate as described herein. Embodiments of the present invention employ any computer useable or readable medium, known now or in the future. Examples of computer useable mediums include, but are not limited to, primary storage devices (e.g., any type of random access memory), secondary storage devices (e.g., hard drives, floppy disks, CD ROMS, zip disks, tapes, magnetic storage devices, optical storage devices, MEMs, nanotechnology-based storage device, etc.), and communication mediums (e.g., wired and wireless communication networks, local area networks, wide area networks, intranets, etc.). E. Conclusion While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be understood by those skilled in the relevant art(s) that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. Accordingly, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
|
G
|
G06
|
G06F
|
17
|
30
|
|||
11894385
|
US20090051105A1-20090226
|
Sheet separating apparatus and method
|
ACCEPTED
|
20090211
|
20090226
|
[]
|
B65H702
|
["B65H702", "G03G2114"]
|
7611143
|
20070821
|
20091103
|
271
|
265020
|
93928.0
|
JOERGER
|
KAITLIN
|
[{"inventor_name_last": "Walsh", "inventor_name_first": "Martin R.", "inventor_city": "St. Albans", "inventor_state": "", "inventor_country": "GB"}, {"inventor_name_last": "Purnell", "inventor_name_first": "Adrian", "inventor_city": "Kingswood", "inventor_state": "", "inventor_country": "GB"}]
|
A sheet separating mechanism and a method of separating sheets is provided to prevent the multifeeding of sheets into printers or copiers. The sheet separating mechanism provides a first nip and a second nip for feeding a series of sheets therebetween. The first nip can include a first motor and the second nip can include a second motor for feeding a leading sheet from the first nip to the second nip. The mechanism further provides a first sensor for sensing a trailing edge of the leading sheet and a second sensor for sensing a leading edge of the leading sheet. The first sensor is upstream of the first motor and the second sensor is downstream of the second motor. A trailing sheet can be prevented from feeding with the leading sheet by stopping the first motor when the leading edge of the leading sheet is sensed by the second sensor while simultaneously the first sensor remains occluded.
|
1. A sheet separating apparatus for a sheet feeder comprising: a first nip and a second nip for feeding a series of sheets therebetween; said first nip includes a first motor and said second nip includes a second motor for feeding a leading sheet from said first nip to said second nip; a first sensor for sensing a trailing edge of said leading sheet and a second sensor for sensing a leading edge of said leading sheet wherein said first sensor is upstream of said first motor and said second sensor is downstream of said second motor; and, a trailing sheet is prevented from feeding with said leading sheet by stopping said first motor when said leading edge of said leading sheet is sensed by said second sensor while simultaneously said first sensor remains occluded. 2. The apparatus of claim 1, wherein said leading sheet has a predetermined length. 3. The apparatus of claim 2, further including a timer for timing the duration of time between entry of said leading edge and exit of said trailing edge of said leading sheet with said second sensor. 4. The apparatus of claim 3, wherein said duration is compared with a predetermined time based upon said predetermined sheet length; and, said underlying sheet becomes a next leading sheet and said first motor feeds said trailing sheet from said first nip to said second nip when said duration is substantially equal to said predetermined time. 5. The apparatus of claim 1, wherein said first nip and said second nip have a fixed spacing therebetween. 6. The apparatus of claim 5, wherein a leading edge of said trailing sheet is stopped at a wait point when said first motor is stopped; and, said wait point is positioned between said first nip and said second nip. 7. The apparatus of claim 6, wherein said wait point is upstream from said second motor. 8. The apparatus of claim 1, wherein said trailing sheet has a leading edge; and, said leading edge of said leading sheet is offset and downstream from said leading edge of said trailing sheet. 9. A xerographic system, comprising: a sheet feeding apparatus having a first nip and an associated first sensor upstream from a second nip and an associated second sensor; said first nip having a feed motion adapted to feed at least a pair of sheets in a feed direction from said first nip toward said second nip during said feed motion; said second nip having a feed motion adapted to feed a leading sheet from said at least a pair of sheets in said feed direction; and, said first nip adapted to halt said feed motion responsive to said first and second sensors wherein a trailing sheet is stopped at a wait point positioned between said first nip and said second nip until said top sheet clears said second sensor. 10. The system of claim 9, wherein said pair of sheets each have a predetermined length. 11. The system of claim 10, further including a timer for timing the duration of time between entry of a leading edge and exit of a trailing edge of said leading sheet with said second sensor. 12. The system of claim 11, wherein said duration is compared with a predetermined time based upon said predetermined sheet length; and, said trailing sheet becomes a next leading sheet and said first motor feeds said trailing sheet from said first nip to said second nip when said duration is substantially equal to said predetermined time. 13. The system of claim 12, wherein said first nip and said second nip have a fixed spacing therebetween. 14. The system of claim 13, wherein a leading edge of said trailing sheet is stopped at said wait point when said first motor is stopped. 15. The system of claim 14, wherein said leading edge of said leading sheet is offset and downstream from said leading edge of said trailing sheet. 16. A method of feeding sheets to a printer or a copier, comprising: applying a feed force in a feed direction to a leading sheet; feeding said leading sheet from a first nip to a second nip wherein said first nip includes a first motor and said second nip includes a second motor; sensing a trailing edge of said leading sheet with a first sensor and sensing a leading edge of said leading sheet with a second sensor wherein said first sensor is upstream of said first motor and said second sensor is downstream of said second motor; and, preventing a trailing sheet from feeding with said top sheet by stopping said first motor when said leading edge of said leading sheet is sensed by said second sensor while simultaneously said first sensor remains occluded. 17. The method of claim 16, wherein said leading sheet has a predetermined length. 18. The method of claim 17, wherein said first nip and said second nip have a fixed spacing therebetween. 19. The method of claim 18, wherein said trailing sheet has a leading edge; and, said leading edge of said leading sheet is offset and downstream from said leading edge of said trailing sheet. 20. The method of claim 19, further comprising comparing a time between sensing said leading edge and said trailing edge of said leading sheet by said second sensor with a predetermined time, if said time is substantially equal to said predetermined time, then said trailing sheet becomes the next leading sheet; and, feeding said next leading sheet from said first nip to said second nip.
|
<SOH> BACKGROUND <EOH>This disclosure is related to the feeding of media sheets in a printer or copier and more particularly to detecting and preventing multifeeds of sheets. Multifeeds of media sheets in a printer or copier can be typically caused by welding of sheet edges, porosity of sheets, adhesion and static charge between sheets, as well as separate sheets being fed from multiple feed trays. A vacuum sheet feeding system can reduce some but not all multifeeds of sheets. When multifeeds do occur, the multiple sheets can jam the printer or copier forcing an operator to fix the jam, intervene with the print job, and possibly even damaging the printer or copier. Quite often the multifeed will manifest itself as a “shingle” multifeed. In this case, the multifed sheets are not exactly overlapped and will have an offset. Due to the overlap, it is possible to separate the sheets by holding the trailing sheet in the previous set of nips and allowing the leading sheet to be taken away. The present disclosure provides for an apparatus and method to detect and separate shingle sheets and thereby reduce multifeed/jam rates.
|
<SOH> SUMMARY OF THE DISCLOSURE <EOH>In one arrangement, a sheet separating mechanism is provided to prevent the multifeeding of sheets into printers or copiers. The sheet separating mechanism provides a first nip and a second nip for feeding a series of sheets therebetween. The first nip can include a first motor and the second nip can include a second motor for feeding a leading sheet from the first nip to the second nip. The mechanism further provides a first sensor for sensing a trailing edge of the leading sheet and a second sensor for sensing a leading edge of the leading sheet. The first sensor is upstream of the first motor and the second sensor is downstream of the second motor. A trailing sheet can be prevented from feeding with the leading sheet by stopping the first motor when the leading edge of the leading sheet is sensed by the second sensor and when the first sensor remains occluded. In another arrangement, a xerographic system is provided to prevent multifeeding of sheets. The system provides a sheet feeding apparatus having a first nip and a first sensor upstream from a second nip and a second sensor. The system further provides that the first nip includes a feed motion adapted to feed a pair of sheets in a feed direction from the first nip toward the second nip during the feed motion. The second nip includes a feed motion adapted to feed a leading sheet from the pair of sheets in the feed direction. The first nip is adapted to halt the feed motion responsive to the first and second sensors wherein a trailing sheet is stopped at a wait point positioned between the first nip and the second nip until the leading sheet clears the second sensor. The disclosure further provides a method of feeding sheets to a printer or a copier comprising applying a feed force in a feed direction to a leading sheet. The feeding of the leading sheet can be from a first nip to a second nip wherein the first nip includes a first motor and the second nip includes a second motor. The first sensor can sense a trailing edge of the leading sheet and the second sensor can sense a leading edge of the leading sheet wherein the first sensor is upstream of the first motor and the second sensor is downstream of the second motor. The method prevents a trailing sheet from feeding with the leading sheet by stopping the first motor when the leading edge of the leading sheet is sensed by the second sensor while simultaneously the first sensor remains occluded.
|
BACKGROUND This disclosure is related to the feeding of media sheets in a printer or copier and more particularly to detecting and preventing multifeeds of sheets. Multifeeds of media sheets in a printer or copier can be typically caused by welding of sheet edges, porosity of sheets, adhesion and static charge between sheets, as well as separate sheets being fed from multiple feed trays. A vacuum sheet feeding system can reduce some but not all multifeeds of sheets. When multifeeds do occur, the multiple sheets can jam the printer or copier forcing an operator to fix the jam, intervene with the print job, and possibly even damaging the printer or copier. Quite often the multifeed will manifest itself as a “shingle” multifeed. In this case, the multifed sheets are not exactly overlapped and will have an offset. Due to the overlap, it is possible to separate the sheets by holding the trailing sheet in the previous set of nips and allowing the leading sheet to be taken away. The present disclosure provides for an apparatus and method to detect and separate shingle sheets and thereby reduce multifeed/jam rates. SUMMARY OF THE DISCLOSURE In one arrangement, a sheet separating mechanism is provided to prevent the multifeeding of sheets into printers or copiers. The sheet separating mechanism provides a first nip and a second nip for feeding a series of sheets therebetween. The first nip can include a first motor and the second nip can include a second motor for feeding a leading sheet from the first nip to the second nip. The mechanism further provides a first sensor for sensing a trailing edge of the leading sheet and a second sensor for sensing a leading edge of the leading sheet. The first sensor is upstream of the first motor and the second sensor is downstream of the second motor. A trailing sheet can be prevented from feeding with the leading sheet by stopping the first motor when the leading edge of the leading sheet is sensed by the second sensor and when the first sensor remains occluded. In another arrangement, a xerographic system is provided to prevent multifeeding of sheets. The system provides a sheet feeding apparatus having a first nip and a first sensor upstream from a second nip and a second sensor. The system further provides that the first nip includes a feed motion adapted to feed a pair of sheets in a feed direction from the first nip toward the second nip during the feed motion. The second nip includes a feed motion adapted to feed a leading sheet from the pair of sheets in the feed direction. The first nip is adapted to halt the feed motion responsive to the first and second sensors wherein a trailing sheet is stopped at a wait point positioned between the first nip and the second nip until the leading sheet clears the second sensor. The disclosure further provides a method of feeding sheets to a printer or a copier comprising applying a feed force in a feed direction to a leading sheet. The feeding of the leading sheet can be from a first nip to a second nip wherein the first nip includes a first motor and the second nip includes a second motor. The first sensor can sense a trailing edge of the leading sheet and the second sensor can sense a leading edge of the leading sheet wherein the first sensor is upstream of the first motor and the second sensor is downstream of the second motor. The method prevents a trailing sheet from feeding with the leading sheet by stopping the first motor when the leading edge of the leading sheet is sensed by the second sensor while simultaneously the first sensor remains occluded. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view of a pair of shingled sheets, in one exemplary arrangement; FIG. 2 is a side elevation view of a sheet feeding system including a sheet separating mechanism with the shingled sheets engaged with a first nip; FIG. 3 is a side elevation view of a sheet feeding system including a sheet separating mechanism with a leading sheet engaged with a second nip; FIG. 4 is side elevation depiction of the sheet feeding system of FIG. 2 showing a sheet separating mechanism drive configuration; FIG. 5 is side elevation depiction of the sheet feeding system of FIG. 2 showing a sheet separating mechanism drive configuration with the shingled sheets separated; and, FIG. 6 is a flow chart depicting the disclosed method for detecting and separating multifed sheets. DETAILED DESCRIPTION FIGS. 1 and 2 show a side elevation view of a pair of shingled sheets, in one exemplary arrangement, and a sheet feeding system, respectively. The sheet feeding system displays a pair of sheets 22, 24 being fed through the system to a printer or copier (not shown). In particular, the pair of sheets 22, 24 are being inadvertently fed through the system in a shingled multifeed fashion. If the shingled sheets advance through the system in this fashion, a jam will result. The cause of the shingled multifed sheets can be any number of reasons including, but not limited to, the following; welding of sheet edges, porosity of sheets, adhesion, static charge between sheets, and sheets being fed from multiple feeder trays. An apparatus and method for detecting and separating shingled sheets is shown in FIG. 2-6 and will be described hereinafter. The sheet feeding system 30 of the present disclosure enables post feeder separation of media sheets. The system 30 includes a first nip 32 along with an associated first motor 34 and first sensor 36. The system 30 further includes a second nip 42 along with an associated second motor 44 and second sensor 46. The second nip 42 is downstream from the first nip 32 relative to the direction of media travel T, i.e. paper path movement. Shingled sheets 22, 24 can be fed via the first motor 34 to a wait point or position 50 with the leading sheet 22 slightly ahead of, in front of, or offset from a trailing sheet 24. The offset shingled sheets 22, 24 can move together from the first nip 32 towards the second nip 42. The leading sheet 22 will reach the second nip 42 first. A leading edge 52 of the leading sheet 22 arrives at the second sensor 46 (refer to FIGS. 3 and 4). If the first sensor 36 does not sense a ‘clear’ signal, i.e. void of media, then the first motor 34 can be stopped. The leading sheet 22 can then be pulled from the first nip 32 and advanced through the second nip 42 via the second motor 44. The leading sheet 22 continues through the second nip 42 until the second sensor 46 ‘goes clear’ (not occluded). If the second sensor 46 goes clear at the expected time, then the trailing sheet 24 is determined to be a shingled sheet occluding the first sensor 36. The trailing sheet 24 can then be fed through the system 30 as the next top sheet thereby eliminating a jam situation and likely shutdown/intervention to the system 30. In one exemplary arrangement, a xerographic system can comprise the sheet feeding apparatus having the first nip 32 and its associated first sensor 36 upstream from the second nip 42 and its associated second sensor 46. The first nip 32 can have a feed motion adapted to feed a pair of sheets 22, 24 in a feed direction from the first nip 32 toward the second nip 42 during the feed motion. The second nip 42 can have a feed motion adapted to feed the leading sheet 22 from the pair of sheets in the feed direction. The first nip 32 can be adapted to halt the feed motion in response to the first and second sensors 36, 46 wherein the trailing sheet 24 is stopped at the wait point 50, which can be positioned between the first nip 32 and the second nip 42, until the leading sheet 22 clears the second sensor 46. The pair of sheets 22, 24 can each be of a predetermined length. The system 30 can further include a timer for timing the duration of time between entry of the leading edge 52 and exit of a trailing edge 54 of the leading sheet 22 with the second sensor 46. The duration of time can be compared with a predetermined time based upon the predetermined sheet length. The trailing sheet 24 can become a next leading sheet and the first motor 34 can feed the trailing sheet 24 from the first nip 32 to the second nip 42 when the duration is substantially equal to the predetermined time. The first nip 32 and the second nip 42 can have a fixed spacing therebetween. The leading edge 62 of the trailing sheet is stopped at the wait point 50 when the first motor 34 is stopped. It is to be appreciated that the leading edge 52 of the leading sheet 22 is offset and downstream from the leading edge 62 of the trailing sheet 24. One exemplary method adapted for feeding sheets to a printer or a copier can be described as follows. Apply a feed force in a feed direction to the leading sheet 22. Feed the leading sheet 22 from the first nip 32 to the second nip 42 wherein the first nip 32 includes the first motor 34 and the second nip 42 includes the second motor 44. Sense the trailing edge 54 of the leading sheet 22 with the first sensor 36 and sense the leading edge 52 of the leading sheet 22 with the second sensor 46 wherein the first sensor 36 is upstream of the first motor 34 and the second sensor 46 is downstream of the second motor 44. The system 30 can prevent the trailing sheet 24 from feeding with the leading sheet 22 by stopping the first motor 34 when the leading edge 52 of the leading sheet 22 is sensed by the second sensor 46 while simultaneously the first sensor 36 remains occluded. Referring to FIGS. 3-5, it is to be appreciated that the first sensor 36 is being occluded by the trailing sheet 24. If the sheets have a predetermined length and the nips have a fixed distance therebetween, then a predetermined duration is known for feeding a sheet from the first nip 32 to the second nip 42. Thus a comparison can be conducted wherein the actual duration between sensing the leading edge 52 and the trailing edge 54 of the leading sheet 22 is measured and compared with the predetermined duration. If the actual duration is substantially equal to the predetermined duration, then the trailing sheet becomes the next leading sheet. The system can then feed the next leading sheet from the first nip 32 to the second nip 42. It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
|
B
|
B65
|
B65H
|
7
|
02
|
|||
10584321
|
US20070281060A1-20071206
|
Process For The Disinfection And/Or Preservation Of Harvested Plant Material
|
ACCEPTED
|
20071121
|
20071206
|
[]
|
A23K303
|
["A23K303", "A23B926", "A23L33508", "A23L3358", "A23B930"]
|
8357413
|
20070802
|
20130122
|
426
|
335000
|
68743.0
|
O'HERN
|
BRENT
|
[{"inventor_name_last": "James", "inventor_name_first": "Alun", "inventor_city": "Blundellsands", "inventor_state": "", "inventor_country": "GB"}, {"inventor_name_last": "French", "inventor_name_first": "Madeline", "inventor_city": "North Cross", "inventor_state": "", "inventor_country": "GB"}, {"inventor_name_last": "Sayle", "inventor_name_first": "Alan", "inventor_city": "Gisburn Clitheroe", "inventor_state": "", "inventor_country": "GB"}, {"inventor_name_last": "King", "inventor_name_first": "Peter", "inventor_city": "Salterforth", "inventor_state": "", "inventor_country": "GB"}]
|
Process for the disinfection and/or preservation of harvested plant material by contacting the harvested plant material with a liquid composition containing at least one peroxygen compound and at least one preservative.
|
1. A process for the disinfection and/or preservation of harvested plant material, the process comprising contacting the harvested plant material with a liquid composition containing at least one peroxygen compound and at least one preservative. 2. The process according to claim 1 wherein the harvested plant material is animal feed chosen from harvested grass, cereals, maize, wheat, legumes and mixtures thereof. 3. The process according to claim 1 wherein the peroxygen compound is chosen from hydrogen peroxide, organic peracids, ester peracids, persalts, metallic peroxides or mixtures thereof. 4. The process according to claim 1 wherein the preservative is an organic acid or salt thereof including acetic, octanoic, benzoic, parahydroxybenzoic, sorbic, ascorbic, citric, lactic, malic, propionic, succinic acid, ester acids and their salts, or mixtures thereof. 5. The process according to claim 1 wherein the liquid composition contains from 5 to 60% wt of the peroxygen compound and from 5 to 25% wt of the preservative. 6. The process according to claim 5 wherein the peroxygen compound is hydrogen peroxide and the preservative is sodium benzoate. 7. The process according to claim 1, wherein the liquid composition is an aqueous solution containing from 0.5 to 40% wt of peracetic acid, from 0.1 to 30% wt of hydrogen peroxide and from 1 to 60% wt of acetic acid. 8. The process according to claim 1 wherein the liquid composition is used in an amount of from 0.5 to 101 per ton of plant material. 9. The process according to claim 8 wherein the liquid composition is used in an amount of from 1 to 3 l per ton of plant material. 10. The process according to claim 1 wherein the liquid composition has a pH of from 1 to 7.
|
The present invention is related to a process for the disinfection and/or preservation of harvested plant material such as grass forage used as animal feed. Forage is generally used as animal feed particularly for cattle and horses. It consists for instance of harvested grasses, cereals, legumes and other plant material. In most cases, it is harvested several times per year during the growing season and stored for use as animal feed for winter when fresh food is not available. Forage is often stored in silos. During storage, micro-organisms may be active in the silo. These micro-organisms can use the forage as nutrients breaking it down to other products. If this micro-organism activity takes place under anaerobic or low oxygen conditions fermentation can occur, converting the nutrients particularly sugars in the forage to organic acids. Eventually the build-up of organic acids and the consequent reduction in pH of the forage can itself reduce or stop the anaerobic micro-organism activity. In this way the forage becomes silage (fermented forage). This micro-organism activity therefore is self-limiting and has a preservative effect on the animal feed. However, conversion of the sugars to acids reduces the nutritional quality of the resulting silage to the animals for which it is intended. This is particularly the case for cattle who have a ruminative digestive system which relies significantly on internal micro-organism activity. Clearly if a proportion of the sugar nutrients in the animal feed are already fermented to acids then the ruminative digestion and therefore the nutritional value to the cattle is reduced. In addition fermentation and acidification of the forage influences the desirability of the forage to the receiving animals eg. cattle and consequent feed conversion rates. High levels of butyric acid in particular are undesirable. Once the forage starts to be taken from storage for use as animal feed, surfaces of the forage become exposed to air and increased oxygen levels. This can allow growth of aerobic micro-organisms such as bacteria, yeasts and moulds which can cause a deterioration in the nutritional quality of the forage and to its acceptability to cattle. Therefore it is important to have a forage treatment which disinfects the forage to reduce initial contamination during harvest and also protects the forage from subsequent infection and growth of micro-organisms, both aerobic and anaerobic throughout the storage period, including the susceptible period when the forage storage area is opened to the air to allow its use for feed. Forage treatments using formic acid or its salts are commonly used. Another example of known treatment is disclosed in the patent application EP 054995 in which calcium peroxide is used to treat fodder. In Kerley MS et al, Science, 230 (4727), p. 820-2 (1985), a hydrogen peroxide system is used on wheatstraw, corncobs and cornstalks. In the abstract CAS 120:132757 of the reference Diouri M., Dissertation, 54 (2), p. 559 (1993), hydrogen peroxide is used in combination with ammonia to treat forage. The purpose of the present invention resides in providing a new method for the disinfection and/or preservation of harvested plant material which reduces micro-organisms activity, supplies oxygen and reduces anaerobic fermentation, thereby maintaining a satisfactory nutritional quality of the harvested plant material as animal feed. A further object of the present invention is to maintain a sufficient desirability or acceptability to the receiving animals, when the harvested plant material is used as animal feed. Another object of the present invention is to reduce initial contamination during harvest but also to protect the harvested forage from subsequent infection and growth of micro-organisms during storage. To this end, the present invention is related to a process for the disinfection and/or preservation of harvested plant material by contacting the harvested plant material with a liquid composition containing at least one peroxygen compound and at least one preservative (such as for instance an organic acid or a salt thereof). One of the essential features of the present invention is to combine a peroxygen compound with a preservative (such as for instance an organic acid or salt). This new combination leads indeed to several benefits such as the animal preference for eating plant material treated with this combination compared with classical products such as formic acid. Another benefit resides in improved milk yield from cattle eating plant material treated by the process of the present invention. Still another benefit resides in the reduction of fermentation of the plant material and therefore in a higher nutritional value such as higher sugar content. Further benefits are: Control of micro-organism activity through disinfection and contribution of oxygen thereby reducing anaerobic fermentation, Maintenance of high sugar content of the plant material thus achieving better digestion and nutritional quality to receiving animals particularly ruminants and also better appearance of the plant material, Preservation to prevent microbial spoilage on opening plant material storage silo or clamp to use for feeding, resulting in exposure of plant material surfaces to oxygen to give aerobic conditions. The term “preservative” means a chemical used to prevent biologic deterioration of materials. This typically necessitates persistence of the chemical in the material to be protected to provide ongoing biostatic activity. The term “harvested plant material” denotes a plant material which has been cut from its cultivation site and which is left on the cultivation site or which is being or has been transported into a storage site such as a silo or another dedicated place in a farm. The cutting can be done by any appropriate machine such as mower, forage harvester or combine harvester, or manually using scythe or shears. The treatment can be done on the cut plant material while it is left on the cultivation site. Alternatively, the treatment can be done during transport from the cultivation site to the storage site. In still another variant, the treatment can be done during loading of the cut plant material in the storage equipment. Finally, the treatment can also be done during storage. The plant material treated by the process of the present invention can be grass e.g. rye grass, Timothy grass, Fescues grass etc.; cereals e.g. maize, wheat, barley, triticale, rye, oats etc.; legumes e.g. peas, clovers, lupins; and seeds e.g. sunflower seeds. The process of the present invention is advantageously applied to plant materials which are harvested and stored to feed animals when fresh food is not available, especially in the winter. Typical examples of such animal feed are grass, cereals and legumes. Particularly good results are obtained with grass, also called grass forage or fodder. In most cases, the plant material treated by the process of the present invention is animal feed chosen from harvested grass, cereals, maize, wheat, legumes and mixtures thereof. The process of the present invention consists in contacting the harvested plant material with a liquid composition. This contacting can be done by any appropriate way that allows a maximum contact of the liquid composition with the cut pieces of the plant material. It can for instance be done by spraying the liquid composition on the harvested plant material or by simply pouring the liquid composition onto the harvested plant material. It is also possible, when a large volume of harvested plant material is stored to gather first a small volume of harvested plant material, contact the upper surface of this volume with the liquid composition, add an additional volume of harvested material on top, contact the upper surface of this additional volume with the liquid composition, and so on, until the total volume is reached. The liquid composition used in the process of the present invention can be chosen from aqueous and non aqueous solutions in which the peroxygen compound and the preservative (such as for instance organic acid or salt) are both dissolved. It can also be chosen from aqueous and non aqueous suspensions in which the peroxygen compound and/or the preservative (for instance the organic acid or salt) and/or another additive is present in the form of solid particles. Aqueous solutions are preferred. The peroxygen compound used in the process of the present invention can be hydrogen peroxide or any precursor which leads to the formation of hydrogen peroxide when dissolved or suspended in the liquid composition. Examples of such precursors can be organic peracids, ester peracids, persalts, metallic peroxides or mixtures thereof. Organic peracids can be chosen from those containing from 1 to 20 carbon atoms, in particular from 1 to 10 carbon atoms, and more particularly from 1 to 6 carbon atoms. They can be for instance performic acid, peracetic acid, peroctanoic acid, and mixtures thereof. Ester peracids can be chosen from those disclosed in the patent applications WO 95/34537, WO 98/28267 and WO 99/67213. They usually have the general chemical formula R—O—CO—(CH2)x—CO3H where R represents an alkyl group having from 1 to 6, in particular from 1 to 4, carbon atoms and x is from 1 to 4. The alkyl group can be linear or branched. Examples of suitable alkyl groups are n- or isopropyl, and n-, iso- or tertiary butyl. Preferably R is a methyl group. In many cases, x is 2, 3 or 4. In a particular embodiment, the liquid composition used in the process of the present invention comprises a mixture of ester peracids where x is 2, 3 and 4, i.e. a mixture of the monoesters of peradipic, perglutaric and persuccinic acids. In a particularly preferred embodiment, the major fraction of the ester peracids present in the liquid composition has x equal to 3. The most preferred ester peracids are the mixtures comprising monomethylesters of peradipic, perglutaric and persuccinic acids. Persalts can be chosen from sodium perborate monohydrate, sodium perborate tetrahydrate, sodium percarbonate, sodium persulphate and mixtures thereof. Sodium percarbonate is especially preferred. Metallic peroxides can be chosen from calcium peroxide, magnesium peroxide, zinc peroxide and mixtures thereof. The most preferred peroxygen compounds are hydrogen peroxide, peracetic acid, and mixtures comprising monomethylesters of peradipic, perglutaric and persuccinic acids. The preservative used in the process of the present invention can be chosen from, but is not limited to, the following: sodium phosphates, sucrose, sulphites, sodium nitrite, sodium chloride, propane-1,2-diol, formaldehyde, acetaldehyde. Preferably, the preservative is an organic acid or a salt thereof. The organic acid can be chosen from organic products having at least one —COOH group. They contain generally at least 2 carbon atoms, in particular at least 3 and in some cases at least 6 carbon atoms. They can contain up to 20 carbon atoms, especially up to 16 carbon atoms, in many cases up to 12 carbon atoms. Typical examples of suitable organic acids are acetic, octanoic, benzoic, parahydroxybenzoic, sorbic, ascorbic, citric, lactic, malic, fumaric, tartaric, propionic, succinic acid, ester acids and their salts, or mixtures thereof. Benzoic acid gives good results. In some cases, it is preferred that, when the peroxygen compound is hydrogen peroxide, the organic acid is different from formic acid. Furthermore, when the peroxygen compound is peracetic acid, it is possible that the liquid composition does not only contain acetic acid as an organic acid but in addition also another organic acid. The salt of an organic acid can be any salt of the above-described organic acids. Sodium, potassium and calcium salts are suitable. Sodium benzoate gives particularly good results. In a particularly advantageous embodiment of the present invention, the peroxygen compound is hydrogen peroxide and the organic acid or salt is sodium benzoate. In the process according to the present invention, the liquid composition contains generally an amount of peroxygen compound of at least 0,5% wt, in particular at least 1% wt, in most cases at least 5% wt. The amount of peroxygen compound is usually at most 60% wt, especially at most 50% wt, very often of at most 40% wt. When the peroxygen compound is hydrogen peroxide, good results are obtained with H2O2 amounts of from 5 to 60% wt, typical H2O2 amounts being about 18% wt, about 20% wt and about 35% wt. When the peroxygen compound is peracetic acid, good results are obtained with amounts of from 0.5 top 40% wt, typical amounts being about 1% wt and about 5% wt. In general, satisfactory results can be obtained with an amount of peroxygen compound of from 5 to 60% wt. In the process according to the present invention, the liquid composition contains generally an amount of preservative of at least 5% wt, in particular at least 7% wt, in most cases at least 10% wt. The amount of preservative is usually at most 25% wt, especially at most 23% wt, most likely at most 20% wt. Good results are obtained with amounts of preservative of from 5 to 25% wt. In the particularly advantageous embodiment of the present invention, in which hydrogen peroxide and sodium benzoate are used, their respective amounts in the liquid composition are preferably from 15 to 35% wt of hydrogen peroxide and from 10 to 20% wt of sodium benzoate. In another embodiment of the present invention the liquid composition is an aqueous solution containing peracetic acid, acetic acid and hydrogen peroxide optionally in combination with an organic acid different from acetic acid. In this other embodiment, the amount of peracetic acid in the liquid composition is generally from 0,5 to 40% wt of peracetic acid (in particular from 1 to 10% wt), from 0,1 to 30% wt of hydrogen peroxide (especially from 5 to 25% wt) and from 1 to 60% wt of acetic acid (in some cases from 20 to 55% wt). In this other embodiment it is recommended to use amounts of peracetic acid and acetic acid so that the molar ratio of acetic acid to peracetic acid is high. For instance this molar ratio can be at least 1, in particular at least 5, values of at least 10 being most common. This molar ratio is usually at most 200, especially at most 100, and very often at most 50. In the process of the present invention, the amounts of peroxygen compound and organic acid or salt are in general such that the molar ratio peroxygen compound to organic acid or salt is at least 0,05, in particular at least 0,1 ratios of at least 0,2 being preferred. This weight ratio can be up to 20, especially up to 10 and in most cases up to 5. In the process of the present invention, the liquid composition is used in an amount of at least 0.5 1 per tonne of plant material, especially at least 0.8 and in most cases at least 1 1 per tonne of plant material. The amount of liquid composition is usually at most 10 l per tonne of plant material, more particularly at most 5 and in many cases at most 3 l per tonne of plant material. Good results are obtained with amounts of liquid compositions of from 0.5 to 10 l per tonne of plant material, and especially from 1 to 3 l per tonne of plant material. In the process of the present invention, it is recommended to use acidic liquid compositions. The pH of the liquid composition is therefore generally at least 1, in particular at least 2 and in some cases at least 4. The pH can be up to 7, for instance up to 6.5 and very often up to 6. Good results are obtained when the liquid composition has a pH of from 1 to 7. The liquid composition used in the process of the present invention can in addition contain other products such as peroxygen stabilizers. Suitable stabilizers include hydroxyl substituted aromatic carboxylic acids and ester derivatives thereof, particularly phenol carboxylic acids such as p-hydroxybenzoic acid and ester derivatives such as methyl or ethyl esters. They also include organic polyphosphonic sequestrants such as ethylidene diphosphonic acid, and aminoploymethylenephosphonic acids, pyridine carboxylic acids especially dipicolinic acid and mixtures thereof. In addition inorganic stabilizers may be used, for example, colloidal tin. They also include mineral acids such as sulphuric or nitric acids. These additional products are usually present in an amount from 0.02 to 20% wt. and in many instances from 0.1 to 10% wt. Having described the invention in general terms, specific embodiments thereof will now be illustrated by way of example only. EXAMPLE 1 50 tonnes perennial rye grass was cut and treated by spray application during cutting. The liquid composition consisted of 17% w/w hydrogen peroxide and 15% w/w sodium benzoate. This was applied at 3 liters liquid composition per tonne of fresh grass. A control of untreated grass was used as a comparison. The 50 tonnes grass forages were stored in a covered clamp under farm conditions for a period up to 12 weeks. A wide range of chemical and microbiological analyses of triplicate samples from the core of the clamp were conducted periodically during the storage period. Selected analyses are shown in Table 1. Analyses 6-9 in Table 1 demonstrate the reduced fermentation of the grass treated with the hydrogen peroxide formulation compared to the control with higher levels of unfermented residual sugars and lower fermentation levels of fermentation products. TABLE 1 Hydrogen Peroxide/ Analysis of stored grass after 12 Sodium Benzoate weeks formulation Control 1. Dry Matter (% w/w) 45.3 42.4 2. Crude Protein (%)* 12.0 12.2 3. Ash (%)* 8.2 8.0 4. pH 4.5 4.2 5. Ammonia - Nitrogen (%)* 1.0 1.0 6. Residual Sugar (%)* 12.4 7.8 7. Ethanol (%)* 0.3 0.5 8. Acetic Acid (%)* <0.1 1.7 9. Total Volatile Fatty Acids (%)* <0.1 1.7 *percentages are on a dry matter basis EXAMPLE 2 As Example 1 but the liquid composition applied to the grass consisted of a peracetic acid formulation with a peracetic acid content of 1.1% w/w, a hydrogen peroxide content of 0.5% and an acetic acid to peracetic acid molar ratio of 1:0.07. The results after 8 weeks storage are shown in Table 2. Analyses 6-10 in Table 2 demonstrate the reduced fermentation of the grass treated with the peracetic acid formulation compared to the control with higher levels of unfermented residual sugars and lower levels of fermentation products. TABLE 2 Analysis of stored grass after 8 Peracetic Acid weeks formulation Control 1. Dry Matter (% w/w) 23.1 20.5 2. Crude Protein (%)* 13.4 14.7 3. Ash (%)* 2.0 7.7 4. pH 4.0 4.3 5. Ammonia - Nitrogen (%)* 1.2 1.0 6. Residual Sugar (%)* 3.6 1.9 7. Ethanol (%)* 0.4 1.2 8. Acetic Acid (%)* 4.4 4.7 9. Propionic Acid (%)* 0.1 0.2 10. Total Volatile Fatty Acids (%)* 4.5 4.8 *percentages are on a dry matter basis EXAMPLE 3 Further farm trials compared alternative treatments with a hydrogen peroxide (35% w/w)/sodium benzoate (10% w/w) formulation on first cut of the season grass during Autumn 2000. Results after 4-5 months storage are shown in Table 3 for farms with grass of similar dry matter content and composition. The grass treated with hydrogen peroxide/sodium benzoate formulation demonstrates lower anaerobic and deleterious fermentation as shown by the much higher level of residual sugars and lower level of volatile fatty acids. TABLE 3 Hydrogen peroxide/ Alternative sodium benzoate chemical Analysis of stored grass formulation treatment Dry Matter (% w/w) 35.5 33 Crude Protein (%)* 11 11.3 pH 4 4.3 Residual Sugar (%)* 6.5 1.8 Lactic Acid (%)* 7.5 4 Volatile Fatty Acids (%)* 2.8 3.5 *percentages are on a dry matter basis EXAMPLE 4 The treatments shown in examples 1 and 2 were also evaluated for their aerobic stability i.e. under conditions representing opening of the clamp to use the forage as feed thus allowing air to enter the clamp. In this case comparisons were made with untreated forage as in examples 1 and 2 and also with forage treated with a typical acid product, formic acid (85% w/w) applied at 2.5 liters per tonne of grass. 750 g of the forages were stored in insulated boxes placed in a controlled environment at 20-22° C. A temperature probe was inserted into each box linked to a data logger to monitor temperature changes hourly over a 6 day period. Temperature increases are due to aerobic micro-organism activity and hence are an indication of aerobic stability of the forage as a function of the treatment applied. Results are shown in Table 4. The data shows improved aerobic stability of the hydrogen peroxide and peracetic acid formulations compared to an untreated control and compared to a typical acid product. TABLE 4 Temperature Temperature (° C.) (° C.) Temperature Forage Treatment Day 0 Day 6 increase (° C.) Untreated Control 18.6 19.5 +0.9 Hydrogen Peroxide/ 18.0 18.0 0.0 Sodium Benzoate formulation as Example 1 Peracetic Acid formulation 18.2 18.7 +0.5 as Example 2 Formic Acid 17.8 20.5 +2.7 EXAMPLE 5 5 tonnes perennial rye grass was cut and treated by spray application during cutting for each of 4 treatments and a control. Treatments 1,3 and 4 were applied as liquid compositions at 3 liters per tonne of fresh grass, whilst Treatment 2 was applied as a liquid composition at 2 liters per tonne of fresh grass. A control of untreated grass was used as a comparison. The 4×5 tonnes grass forages were stored in covered clamps under farm conditions for a period up to 12 weeks. Chemical and microbiological analyses of samples from the core of the clamps were conducted periodically during the storage period. Selected analyses are shown in Table 5. Treatment 1 consisted of 19.5% w/w hydrogen peroxide and 15% w/w sodium benzoate Treatment 2 consisted of 30% w/w hydrogen peroxide and 22.5% w/w sodium benzoate Treatment 3 consisted of 15% w/w sodium benzoate Treatment 4 consisted of 19.5% hydrogen peroxide TABLE 5 Analysis of stored Treatments grass after 12 weeks 1 2 3 4 Control 1. Dry Matter (% w/w) 44.8 46.3 44.9 48 43.3 2. Crude protein (%)* 12 13 13.6 11.5 12.9 3. Ash (%)* 8.5 8.3 8.2 8.2 9.6 4. pH 4.3 4.5 4.3 4.2 4.5 5. Ammonium - 1.8 3.1 3 3 4 Nitrogen (%)* 6. Sugars (%)* 8.6 10.2 7.3 8.9 5.1 7. Temperature of 19.5 16.3 20 24.7 26 forage in clamp (° C.) *percentages are on a dry matter basis As shown in previous examples, analysis of sugar content (6) show that treatments with compositions containing both hydrogen peroxide and sodium benzoate (Treatments 1 & 2) show reduced fermentation of the grass compared to the control or to the compositions containing benzoate only (Treatment 3) with higher levels of unfermented residual sugars. The benefit of the combination treatments (Treatments 1 & 2) on fermentative activity is also clearly illustrated by the temperature (7) measured in the centre of the clamps during sampling. Treatments 1 and 2 show a lower temperature compared to the control or to either of the additives applied alone (Treatments 3 & 4).
|
A
|
A23
|
A23K
|
3
|
03
|
|||||
11624805
|
US20080038991A1-20080214
|
Submerged Fluid Jet Polishing
|
ACCEPTED
|
20080130
|
20080214
|
[]
|
B24C300
|
["B24C300"]
|
7749049
|
20070119
|
20100706
|
451
|
007000
|
57366.0
|
ROSE
|
ROBERT
|
[{"inventor_name_last": "Hunter", "inventor_name_first": "John H.", "inventor_city": "Almonte", "inventor_state": "", "inventor_country": "CA"}, {"inventor_name_last": "Miller", "inventor_name_first": "Ian J.", "inventor_city": "Ottawa", "inventor_state": "", "inventor_country": "CA"}, {"inventor_name_last": "Nilson", "inventor_name_first": "John", "inventor_city": "Ottawa", "inventor_state": "", "inventor_country": "CA"}, {"inventor_name_last": "Senechal", "inventor_name_first": "Gregg", "inventor_city": "Orleans", "inventor_state": "", "inventor_country": "CA"}, {"inventor_name_last": "Wimperis", "inventor_name_first": "Jeff", "inventor_city": "Portland", "inventor_state": "", "inventor_country": "CA"}]
|
Fluid jet polishing (FJP) is a method of contouring and polishing a surface of a component by aiming a jet of a slurry of working fluid from a nozzle at the component and eroding the surface to create a desired shape. During erosion, the end of the nozzle and the component are submerged within the working fluid, whereby air is not introduced into the closed loop of working fluid slurry. Any bubbles that are present in the system simply bubble to an air pocket at the top of the erosion chamber and are not re-circulated, thereby producing surfaces with very smooth surface finishes.
|
1. A fluid jet polishing system comprising: a chamber for enclosing a component during polishing; a holder for holding the component in the chamber during polishing; working fluid, including abrasive particles, filling the chamber above a desired level; a nozzle, having an end disposed below the desired level, for directing a pressurized stream of working fluid at the component; and a motion system providing relative motion between the holder and the nozzle providing a material removal rate from a surface of the component; wherein the holder and the end of the nozzle are submerged in working fluid, while the stream of working fluid is directed at the component, whereby ambient air is not introduced into the working fluid; and wherein the working fluid includes a dilatant additive for increasing the viscosity of the working fluid at an interface between the pressurized stream of working fluid and the surface of the component. 2. The system according to claim 1, further comprising a recirculation system for recirculating the working fluid from the chamber back to the nozzle. 3. The system according to claim 2, wherein the recirculation system comprises a pump for re-pressurizing the working fluid; and pipes for directing the working fluid between the chamber and the pump, and between the pump and the chamber. 4. The system according to claim 2, further comprising a temperature controller for adjusting the temperature of the working fluid during recirculation for controlling the removal rate of particulate matter from the component. 5. The system according to claim 4, wherein the temperature controller comprises a temperature sensor for determining the temperature of the working fluid; and a heating/cooling means for adjusting the temperature of the working fluid. 6. The system according to claim 1, wherein the motion system includes computerized control means for reciprocating the nozzle back and forth over the component, whereby the nozzle dwells over different areas of the component based on predetermined desired characteristics. 7. The system according to claim 6, further comprising sensors for determining characteristics of the component during particulate matter removal for comparing current characteristics to the predetermined desired characteristics. 8. The system according to claim 1, wherein the nozzle is perpendicular to the component for providing an annular profile of particulate matter removal. 9. The system according to claim 1, wherein the nozzle is at an acute angle to a line vertical to the component providing a teardrop shaped profile of particulate matter removal. 10. A fluid jet polishing system comprising: a chamber for enclosing a component during polishing; a holder for holding the component in the chamber during polishing; working fluid, including abrasive particles, filling the chamber above a desired level; a nozzle, having an end disposed below the desired level, for directing a pressurized stream of working fluid at the component; a motion system providing relative motion between the holder and the nozzle providing a material removal rate from a surface of the component; and air injection means for adding air into the working fluid for increasing the removal rate and surface roughness of the component; wherein the holder and the end of the nozzle are submerged in working fluid, while the stream of working fluid is directed at the component 11. The system according to claim 1, further comprising stirring means for affecting the properties of the working fluid to maintain the abrasive particles in the working fluid suspension, thereby optimizing the removal rate and surface roughness. 12. A fluid jet polishing system comprising: a chamber for enclosing a component during polishing; a holder for holding the component in the chamber during polishing; working fluid, including abrasive particles, filling the chamber above a desired level; a nozzle, having an end disposed below the desired level, for directing a pressurized stream of working fluid at the component; a motion system providing relative motion between the holder and the nozzle providing a material removal rate from a surface of the component; and an air pocket in the chamber, whereby any bubbles that are present in the system bubble to the air pocket and are not re-circulated; wherein the holder and the end of the nozzle are submerged in working fluid, while the stream of working fluid is directed at the component, whereby ambient air is not introduced into the working fluid. 13. The system according to claim 1, further comprising pressure changing means for altering the removal rate and surface roughness of the component. 14. The system according to claim 1, wherein the nozzle has an adjustable opening for adjusting the removal rate and resolution of removal. 15. The system according to claim 1, further comprising height adjustment means for adjusting a height of the nozzle above the component, thereby adjusting the removal rate and surface roughness of the component. 16. The system according to claim 1, further comprising an additional nozzle and an additional motion system for directing a pressurized stream of working fluid at another surface of the component. 17. A fluid jet polishing system comprising: a chamber for enclosing a component during polishing; a holder for holding the component in the chamber during polishing; working fluid, including abrasive particles, filling the chamber above a desired level; a nozzle, having an end disposed below the desired level, for directing a pressurized stream of working fluid at the component; and a motion system providing relative motion between the holder and the nozzle providing a material removal rate from a surface of the component; a recirculation system for recirculating the working fluid from the chamber back to the nozzle; and a pH controller for monitoring and adjusting the pH of the working fluid during re-circulation for controlling the removal rate of particulate matter from the component; wherein the holder and the end of the nozzle are submerged in working fluid, while the stream of working fluid is directed at the component, whereby ambient air is not introduced into the working fluid. 18. The system according to claim 1, wherein the abrasive particles have a specific gravity greater than 5. 19. The system according to claim 12, wherein the working fluid includes a dilatant additive for increasing the viscosity of the working fluid at an interface between the pressurized stream of working fluid and the surface of the component. 20. The system according to claim 1, wherein the working fluid further comprises a suspension agent for maintaining the abrasive particles suspended in the working fluid. 21. A fluid jet polishing system comprising: a chamber for enclosing a component during polishing; a holder for holding the component in the chamber during polishing; working fluid, including abrasive particles, filling the chamber above a desired level; a nozzle, having an end disposed below the desired level, for directing a pressurized stream of working fluid at the component; and a motion system providing relative motion between the holder and the nozzle providing a material removal rate from a surface of the component; wherein the working fluid includes a dilatant additive for increasing the viscosity of the working fluid at an interface between the pressurized stream of working fluid and the surface of the component, and a suspension agent for maintaining the abrasive particles suspended in the working fluid.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Fluid jet polishing (FJP) is a method of contouring and polishing a surface of a component by aiming a jet of a slurry of working fluid at the component and eroding the surface to create a desired shape. Fluid jet polishing has been studied in some detail, in particular by Silvia M. Booij see ISBM 90-9017012-X, 2003. A conventional fluid jet polishing system 1 , illustrated in FIGS. 1 and 2 , comprises the following: a part holder 2 , which holds a component 3 to be eroded; a contained area 4 a with a drain 4 b ; a volume of working fluid 5 , e.g. water, glycol, oil or other suitable fluids; a pump 6 to pressurize the working fluid 5 ; and plumbing 7 to return the working fluid 5 to a nozzle 8 , which directs the working fluid 5 at the component 3 . A motion system 10 , usually computer controlled, directs the nozzle 8 . The profile of the effect of a stationary fluid jet on the surface of the component 3 creates a tool pattern. A computer program is then used to optimize the dwell time of the tool pattern on the surface of the component 3 in order to achieve the desired final surface figure. Typically the pressure of the slurry of working fluid 5 remains constant and the velocity (or dwell time) of the nozzle 8 is varied to remove the desired amount of material from different areas of the component 3 . Alternatively the nozzle 8 can remain fixed and the component 3 can be moved. A temperature controller may be added to maintain the fluid at a constant temperature. One of the key challenges with FJP is creating a uniform continuous stream of the working fluid 5 . Typically, the working fluid 5 contains small abrasive particles made from hard materials, such as Aluminum Oxide, Diamond and/or Zirconium Oxide in a carrier fluid, e.g. water or similar fluid. The small abrasive particles have a certain negative buoyancy in the working fluid, whereby the impact of the abrasive particles on the surface of the component 3 depends on the speed of the abrasive particles and the buoyancy of the abrasive particles in the working fluid 5 . However, air bubbles in the slurry can cause inconsistency in the polishing by dramatically altering the buoyancy of the particles, which causes the particles to damage the surface of the component 3 and increase the surface roughness of the finished surface. The viscosity of air is also much lower than the carrier fluid, so the movement of the abrasive particles to the interface between the working fluid 5 and the surface of the component 3 is faster. When the jet of working fluid 5 impacts the surface of the component 3 , the direction of the flow changes. As the working fluid 5 changes direction, particles suspended therein change direction and experience a force in the direction of the surface. The greater the density difference between the abrasive particles and the working fluid 5 , the higher the force toward the surface will be. Centrifugal force drive the particles into the surface and creates the tool profile. The centrifugal force is resisted by the viscosity of the carrier fluid. Smaller abrasive particles have a larger ratio of cross sectional area to mass, which also decreases the ratio of centrifugal force to viscous drag. The response of materials tested to date with the fluid jet process indicates a non-linear response to increasing the centrifugal force/drag ratio. In a Newtonian fluid (viscosity constant with shear, for example water), an abrasive particle density of 7 g/cm 3 or more is preferred. Particle size not only affects the centrifugal force/drag ratio, but also affects the material removal rate. Larger abrasive particles increase the material removal rate, but also increase the finished surface roughness. Another similar technology, disclosed in U.S. Pat. No. 5,951,369 issued Sep. 14, 1999 to Kordonski et al, is called Magneto Rheological Finishing, (MRF). The technology uses a liquid slurry that is directed to a wheel, where it is stiffened by magnetic fields. The stiff slurry is then carried by the wheel into contact with the component to be finished. After rubbing past the component and causing erosion the slurry is then returned to its liquid state for re-circulation by removal from the magnetic field. The advantage of MRF is that the stiffened slurry provides rapid material removal. The disadvantage is that the magnet and wheel technology makes the process significantly more complex and expensive than fluid jet polishing. An object of the present invention is to overcome the shortcoming of the prior art by providing a relatively simple, but highly effective fluid jet polishing system providing much smoother and much more accurately figured surfaces than conventional polishing systems.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, the present invention relates to a fluid jet polishing system comprising: a chamber for enclosing a component during polishing; a holder for holding the component in the chamber during polishing; working fluid, including abrasive particles, filling the chamber above a desired level; a nozzle, having an end disposed below the desired level, for directing a pressurized stream of working fluid at the component; and a motion system providing relative motion between the holder and the nozzle providing a material removal rate from a surface of the component; wherein the holder and the end of the nozzle are submerged in working fluid, while the stream of working fluid is directed at the component, whereby ambient air is not introduced into the working fluid.
|
CROSS-REFERENCE TO RELATED APPLICATIONS The present invention claims priority from U.S. Patent Application No. 60/803,161 filed May 25, 2006, which is incorporated herein by reference. TECHNICAL FIELD The present invention relates to fluid jet polishing, and in particular to fluid jet polishing in a submerged system. BACKGROUND OF THE INVENTION Fluid jet polishing (FJP) is a method of contouring and polishing a surface of a component by aiming a jet of a slurry of working fluid at the component and eroding the surface to create a desired shape. Fluid jet polishing has been studied in some detail, in particular by Silvia M. Booij see ISBM 90-9017012-X, 2003. A conventional fluid jet polishing system 1, illustrated in FIGS. 1 and 2, comprises the following: a part holder 2, which holds a component 3 to be eroded; a contained area 4a with a drain 4b; a volume of working fluid 5, e.g. water, glycol, oil or other suitable fluids; a pump 6 to pressurize the working fluid 5; and plumbing 7 to return the working fluid 5 to a nozzle 8, which directs the working fluid 5 at the component 3. A motion system 10, usually computer controlled, directs the nozzle 8. The profile of the effect of a stationary fluid jet on the surface of the component 3 creates a tool pattern. A computer program is then used to optimize the dwell time of the tool pattern on the surface of the component 3 in order to achieve the desired final surface figure. Typically the pressure of the slurry of working fluid 5 remains constant and the velocity (or dwell time) of the nozzle 8 is varied to remove the desired amount of material from different areas of the component 3. Alternatively the nozzle 8 can remain fixed and the component 3 can be moved. A temperature controller may be added to maintain the fluid at a constant temperature. One of the key challenges with FJP is creating a uniform continuous stream of the working fluid 5. Typically, the working fluid 5 contains small abrasive particles made from hard materials, such as Aluminum Oxide, Diamond and/or Zirconium Oxide in a carrier fluid, e.g. water or similar fluid. The small abrasive particles have a certain negative buoyancy in the working fluid, whereby the impact of the abrasive particles on the surface of the component 3 depends on the speed of the abrasive particles and the buoyancy of the abrasive particles in the working fluid 5. However, air bubbles in the slurry can cause inconsistency in the polishing by dramatically altering the buoyancy of the particles, which causes the particles to damage the surface of the component 3 and increase the surface roughness of the finished surface. The viscosity of air is also much lower than the carrier fluid, so the movement of the abrasive particles to the interface between the working fluid 5 and the surface of the component 3 is faster. When the jet of working fluid 5 impacts the surface of the component 3, the direction of the flow changes. As the working fluid 5 changes direction, particles suspended therein change direction and experience a force in the direction of the surface. The greater the density difference between the abrasive particles and the working fluid 5, the higher the force toward the surface will be. Centrifugal force drive the particles into the surface and creates the tool profile. The centrifugal force is resisted by the viscosity of the carrier fluid. Smaller abrasive particles have a larger ratio of cross sectional area to mass, which also decreases the ratio of centrifugal force to viscous drag. The response of materials tested to date with the fluid jet process indicates a non-linear response to increasing the centrifugal force/drag ratio. In a Newtonian fluid (viscosity constant with shear, for example water), an abrasive particle density of 7 g/cm3 or more is preferred. Particle size not only affects the centrifugal force/drag ratio, but also affects the material removal rate. Larger abrasive particles increase the material removal rate, but also increase the finished surface roughness. Another similar technology, disclosed in U.S. Pat. No. 5,951,369 issued Sep. 14, 1999 to Kordonski et al, is called Magneto Rheological Finishing, (MRF). The technology uses a liquid slurry that is directed to a wheel, where it is stiffened by magnetic fields. The stiff slurry is then carried by the wheel into contact with the component to be finished. After rubbing past the component and causing erosion the slurry is then returned to its liquid state for re-circulation by removal from the magnetic field. The advantage of MRF is that the stiffened slurry provides rapid material removal. The disadvantage is that the magnet and wheel technology makes the process significantly more complex and expensive than fluid jet polishing. An object of the present invention is to overcome the shortcoming of the prior art by providing a relatively simple, but highly effective fluid jet polishing system providing much smoother and much more accurately figured surfaces than conventional polishing systems. SUMMARY OF THE INVENTION Accordingly, the present invention relates to a fluid jet polishing system comprising: a chamber for enclosing a component during polishing; a holder for holding the component in the chamber during polishing; working fluid, including abrasive particles, filling the chamber above a desired level; a nozzle, having an end disposed below the desired level, for directing a pressurized stream of working fluid at the component; and a motion system providing relative motion between the holder and the nozzle providing a material removal rate from a surface of the component; wherein the holder and the end of the nozzle are submerged in working fluid, while the stream of working fluid is directed at the component, whereby ambient air is not introduced into the working fluid. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in greater detail with reference to the accompanying drawings which represent preferred embodiments thereof, wherein: FIG. 1 is a side view of a conventional fluid jet polishing system; FIG. 2 is a side view of the nozzle and component of the fluid jet polishing system of FIG. 1; FIG. 3 is a side view of the fluid jet polishing system according to the present invention; and FIG. 4 is a side view of the nozzle and component of a fluid jet polishing system according to another embodiment of the present invention. DETAILED DESCRIPTION With reference to FIGS. 3 and 4, a fluid jet polishing system 11, according to the present invention, includes a part holder 12, which securely holds a component 13 during the erosion process within a contained area of an erosion chamber 16. The part holder 12 can be fixed within the erosion chamber 16, rotatable relative to the erosion chamber 16 or form part of a moveable platform, as will be discussed hereinafter. Rotating the part holder 12 facilitates the production of annular or arcuate profiles. A nozzle 17 directs a pressurized fluid jet stream of a working fluid 18 at a surface of the component 13. The working fluid 5 contains a carrier fluid, e.g. water, glycol, oil or other suitable fluids, and small abrasive particles made from harder materials, such as Aluminum Oxide, Diamond and/or Zirconium Oxide. Varying the type and size of the abrasive particles can be done in order to optimize the surface roughness and/or removal rate. The properties of the working fluid 18 including fluid density, viscosity, pH and rheological properties, can be altered in order to optimize the surface roughness and removal rate, in particular it will be advantageous to have a dilatant fluid in order to increase the removal rate. The viscosity of dilatant fluids increases with increasing shear forces, as compared to normal fluids, in which viscosity is independent of shear forces. Accordingly, when a fluid jet stream including a dilatant fluid impacts on the component 13, the working fluid 5 experiences high shear forces, and therefore has an increase in viscosity, in particular at an interface between the pressurized stream of working fluid 18 and the surface of the component 13. Abrasive particles that normally have very little effect on the component 13, work much better when a dilatant additive, e.g. corn starch or poly vinyl alcohol, is added. Poly vinyl alcohol is a long chain molecule that can be cross linked to form larger molecules, all with varying degrees of dilatant property. One of the key parameters for selecting good abrasives is density, because very dense particles come out of the working fluid 18, or move to the edge thereof, very quickly and are more aggressive. Air in the working fluid 18 rapidly increases the removal rate, because the decrease in buoyancy and reduction in viscosity resulting from the air causes the abrasive particles to hit the surface of the component 13 very hard; however, particles with low density (high buoyancy) do not come out of the working fluid 18 easily and do not have much affect on the component 13. If suspension agents are added to keep the particles in suspension then the erosion process seems to stop all together. Accordingly, selecting abrasive particles with high density or low buoyancy in the carrier fluid, e.g. water, is important in creating a relatively rapid removal rate. For example, cerium oxide has a specific gravity of 7.8, and zirconium oxide has a specific gravity of 5.8; accordingly abrasive particles with a specific gravity greater than 5 is preferred. Keeping the dense abrasive particles in suspension in the working fluid 18 is normally difficult and requires stirring or the use of a suspension agent to maintain. Unfortunately, as hereinbefore noted, the suspension agent, by itself, may prevent the abrasive particles from moving to the edge of the flow and doing work. However, the dilatant additive seems to solve this problem by stiffening the fluid and holding the particles quite firmly in the working fluid 18 and greatly increasing the pressure on the component 13. Accordingly, adding both a dilatant additive and a suspension agent to the working fluid 18 is a preferable combination, which eliminates the need for stirring, while providing good removal rates for a wide variety of particle densities. The aqueous suspension agent can be selected from the group consisting of: stearic acid, palmitic acid, myristic acid, lauric acid, coconut oil, palm oil, peanut oil, ethylene glycol, propylene glycol, glycerol, polyethylene glycol aliphatic polyethers, alkyl sulfates, and alkoxylated alkylphenols. The suspension agent can also be an aqueous mixture containing fat and/or fatty acid; a mixture of stearic acid and a vegetable oil; or a material sold under the trademark EVERFLO®, which comprises mostly water, about 12½ wt % stearic acid, about 12½ wt % vegetable oil, and small amounts of methyl paraben and propylene glycol. Other suspension agents may also be used. Multiple axis (3, 4, 5 or 6) motion systems may be used to process a wide variety of component shapes. A mechanical linkage may also be added to maintain the tool angle over spherical or aspheric component and thereby reduce the need for multi-axis motion control systems During erosion the end of the nozzle 17 and the component 13 are submerged within the working fluid 18, whereby ambient air is not introduced into the closed loop of working fluid slurry. Any air bubbles that are present in the system simply bubble to an air pocket 15 at the top of the erosion chamber 16 and are not re-circulated, thereby producing surfaces with very smooth surface finishes. The air pocket 15 can be vented continuously or at time intervals. A drain pipe 19 at the bottom of the erosion chamber 16 evacuates the erosion chamber 16 and passes the working fluid 18 with eroded particles from the component 13 to a pump 21, which re-pressurizes the working fluid 18. Plumbing pipes 22 are used to return the working fluid 18 back to the nozzle 17. A motion system 23, which is usually computer controlled, directs the nozzle 17 in the x-y directions or in any suitable directions, e.g. x-y-z-θz-θy-θx, over the component 13 in accordance with the desired pattern and smoothness on the surface of the component 13. Alternatively, in systems in which the nozzle 17 is fixed and the part holder 12 is moveable, the motion system 23 directs the moveable platform of the part holder 12 as desired to obtain the required surface shape and roughness. A property controller 24, including switch 25 and bypass pipes 26 and 27, may be added to control any one or more of the various properties of the working fluid 18, e.g. temperature, fluid density, viscosity, pH and rheological properties. If temperature control is required, a temperature sensor in the switch 25 determines the temperature of the working fluid 18 and reroutes all or a portion of the working fluid 18 through the property controller 24 via the bypass pipe 26, wherein the temperature of the working fluid 18 is adjusted higher or lower using suitable heating or cooling means. The thermally altered working fluid is passed back to the plumbing 22 via the return bypass pipe 27. The temperature of the working fluid 18 can be adjusted in order to optimize the removal rate of the component particles and/or the surface roughness of the component 13. In particle heating or cooling the tip of the nozzle 17 can affect the properties of the working fluid slurry thereby increasing or decreasing the removal rate, i.e. cooling the working fluid 18 will lead to a stiffer slurry and an increased removal rate. The property controller 24 can alternatively or also include means for altering the pH of the working fluid 18 by adding high or low pH materials thereto for optimizing the removal rate of component material and the surface roughness of the finished product. Preferably, some means for vibrating or stirring the working fluid 18 is provided within the property controller 24 to maintain the abrasive particles in suspension and to optimize the removal rate and surface roughness. The fluid circulation system should be designed with as few horizontal surfaces as possible to minimize settling of the abrasive particles. Mixing by the normal flow of the working fluid 5 through the nozzle 17 and the pump 21 may be sufficient to keep the abrasive in suspension without additional stirring or vibrating means. The profile of the effect of a stationary fluid jet on the surface of a component creates a tool pattern in the shape of an annular ring, e.g. a donut, for a vertical nozzle or in the shape of a teardrop for an angled nozzle. A computer program controlling the motion system 23 is used to optimize the dwell time of the tool pattern on the surface of the component 13 in order to achieve the desired final surface shape and smoothness. Typically, the pressure of the fluid jet of working fluid 18 remains constant and the velocity (or dwell time) of the nozzle 17 is varied to remove the desired amount of material from different areas of the component 13. Alternatively, the pressure of the working fluid 18 can be altered or the nozzle 17 can remain fixed and the component 13 can be moved, e.g. reciprocated, using the moveable platform, as hereinbefore discussed. The pressure of the working fluid 18 can be actively changed during the erosion process to provide different removal rates for different portions of the surface of the component 13. Dwell time calculated for a grid of points distributed over the surface of the optical component 13 can be converted to velocity profile using v(x,y)=d/T(x,y) where v(x,y) is desired velocity between adjacent points and T(x,y) is the calculated dwell time for the second point. Normally, the tool, e.g. nozzle 17, is moved in a raster pattern so the conversion is only applied in one axis. Preferably, the nozzle 17 is disposed substantially vertically for launching a slurry of working fluid 18 at a constant velocity at the surface of the component 13, traveling back and forth in a simple grid pattern in the x and y directions substantially perpendicular to the surface of the component 13 with the dwell time over each position on the grid determining the amount of material removed. The coordinates of the component 13 are predetermined or determined by the computer system, whereby the computer system can then determine the dwell time at each grid position based on the requirements, i.e. desired characteristics, e.g. dimensions, surface roughness, of the finished product. Sensors in the erosion chamber 16 and/or on the part holder 12 can be used to measuring the properties of the component 13, while the component 13 is being processed in order to create a closed loop system, thereby improving the speed and accuracy thereof. To provide added control over the erosion process, the orifice of the nozzle 17 can be provided with an adjustable opening or a plurality of nozzles 17, each with different sized openings, can be provided. To increase the removal rate, the size of the orifice is increased or a nozzle 17 with a larger orifice is used. To increase the resolution of the removal, the size of the orifice is reduced or a nozzle 17 with a smaller opening is used. Alternatively, the shape or angle of the nozzle 17 can be changed or altered to create various tool profiles, e.g. disposing the nozzle 17 at an acute angle from vertical creates a tear drop shaped profile. Multiple nozzles 17 can also be provided to increase the speed of particle removal. The distance of the nozzle 17 from the component 13 can be adjusted between runs or actively during each run in order to optimize the resolution, removal rate of particulate material and surface roughness of the component 13. Masks can be provided to prevent the working fluid 18 from contacting certain areas of the component 13 to thereby create deep channels and concave areas. Air, or some other suitable gas for decreasing buoyancy, can be introduced into the working fluid 18 proximate the nozzle 17 or any other suitable location to increase removal rate or affect the surface roughness of the finished product. With reference to FIG. 4, material can be removed simultaneously from different sides of the component 13, by using one or more nozzles 17′ directed at opposite or different sides of the component 13 at the same time. Independent re-circulating systems can be used for each of the nozzles 17′ to enable the characteristics, e.g. temperature, pH etc, of the working fluids 18 to be independently adjusted. Alternatively, a single re-circulating system can be used for all of the nozzles 17′.
|
B
|
B24
|
B24C
|
3
|
00
|
|||
11744095
|
US20070282748A1-20071206
|
METHOD FOR MANAGING, ROUTING, AND CONTROLLING DEVICES AND INTER-DEVICE CONNECTIONS
|
ACCEPTED
|
20071121
|
20071206
|
[]
|
H04L900
|
["H04L900"]
|
8533326
|
20070503
|
20130910
|
709
|
223000
|
86684.0
|
ZUNIGA ABAD
|
JACKIE
|
[{"inventor_name_last": "Saint Clair", "inventor_name_first": "Gordon", "inventor_city": "San Francisco", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Johnson", "inventor_name_first": "Frederick", "inventor_city": "", "inventor_state": "", "inventor_country": "US"}, {"inventor_name_last": "Badore", "inventor_name_first": "Amy", "inventor_city": "Oakland", "inventor_state": "CA", "inventor_country": "US"}, {"inventor_name_last": "Rotter", "inventor_name_first": "Charles", "inventor_city": "", "inventor_state": "", "inventor_country": "US"}, {"inventor_name_last": "Shah", "inventor_name_first": "Kamal", "inventor_city": "Oakland", "inventor_state": "CA", "inventor_country": "US"}]
|
A system and method for managing, routing and controlling devices and inter-device connections located within an environment to manage and control the environment using a control client is presented. A user provides commands via the control client to a server that maintains a representation of the environment and the devices within the environment. The server provides commands to devices present within the environment in response to user commands and other events, including events from the environment. The commands cause the devices in the environment to adopt specific desired states thereby causing the environment and the devices within the environment to create desired connections by and between the devices and to otherwise control and effect the environment.
|
1. A method for controlling an environment, comprising: Accessing a server associated with the environment via a control client; Logging into said server as a user, wherein said server queries a user database to retrieve rights and configuration data associated with said user; Rendering a control panel on said control client, wherein said control panel is adapted to the environment based on said rights and said configuration data; Creating a user defined configuration of a source device, an output device, and a device associated with the environment; Generating a desired path in the environment based on an environment model to connect said source device to said output device and adapted to allow signal transfer between said source device and said output device, wherein said environment model is stored in a data structure on said server; Communicating one or more commands from said server to a control switch to selectively interconnect an output port of said source device to an input port of said output device; Commanding said source device to output a signal; and, Outputting said signal on said output device. 2. The method of claim 1, further comprising: Transmitting said signal to a conversion device adapted to receive said signal; Communicating desired conversion type information from said server to said conversion device; Converting said signal to a reformatted signal using said desired conversion type information; and, Outputting said reformatted signal from said conversion device to said output device. 3. A method of claim 1, further comprising: Identifying an identified device from a list of said source device, said control device, and said configuration device; Contacting a remote server and requesting a license to use a device driver adapted to interface with said identified device; Encrypting and transmitting said license to said server using a one-way key stored on said remote server; Decrypting said driver using a second one-way key located on said server, wherein said one-way key and said second one-way key are related asymmetric encryption an decryption keys; and, Installing said device driver for said identified device. 4. A method of claim 1, further comprising: Determining whether an additional device driver installation is authorized; Contacting a remote server to request a license modification; Generating said license modification specific to said server to allow said server to install and operate said additional device driver using a one-way key located on said remote server; Transmitting said license modification to said server; Decrypting said license modification using a second one-way key located on said server; and, Installing said license modification on said server authorizing the installation and operation of said additional device driver. 5. A method of claim 1, whereby said rendering said control panel is adapted to said control client's capabilities using a control client driver dataset stored on said server and said rendering further comprises creating a control sub-panel for a permitted device on said control panel, wherein said control sub-panel is based upon said control client driver dataset and said user. 6. A method of claim 1, further comprising controlling a first device associated with the environment and controlling a second device associated with the environment by issuing commands to said first device and said second device from said server. 7. A method of claim 6, wherein said rendering creates a zone control interface adapted to accept a single user input and translate said single user input into a first output and a second output, whereby said translate uses a pre-defined relationship between said first output and said single user input and said second output and said single user input, and whereby said controlling further comprises issuing said first output to said first device and said second output to said second device. 8. A method of claim 1, whereby said output port of said source device is connected to an input node of said control switch by a first static connection and said output node of said control switch is connected to said input port of said output device by a second static connection, wherein said control switch responds to said commands by forming an operable connection between said input node and said output node to allow said signal to flow through said first static connection and said second static connection. 9. A method of claim 8, further comprising: Inputting a set of environment elements comprising said first static connection, said second static connection, said source device, said output device, and said control switch to create said environment model and storing said environment model in a device interconnection and routing database; Identifying said desired path by applying a recursive algorithm to said environment model to identify a reverse path from said output device to said source device; and, Updating said environment model with an attribute to indicate which said environment elements are part of said desired path. 10. A method of claim 9, further comprising: Storing said user defined configuration in said device interconnection and routing database; and, Retrieving said environment model and said user defined configuration from said device interconnection and routing database. 11. A method for configuring information flow in an environment, comprising: mapping static connections in the environment between a plurality of devices associated with the environment, wherein said static connections define paths between said plurality of devices, and allow the information flow; selecting a source device from said plurality of devices, wherein said source device possesses at least a first source device output port; selecting an output device from said plurality of devices, wherein said output device possess at least a first output device input port; applying a means for identifying a reverse path through said static connections from said first output device input port to said first source device output port with a recursive algorithm; selecting a subset of devices from said plurality of devices that are connected by said reverse path through said static connections; and, configuring said subset of devices to accept the information flow from said first source device output port and route the information flow to said first output device input port. 12. A method of claim 11, further comprising: storing said mapping of and a set of attributes for said static connections and said plurality of devices in a database; loading into a working model said set of attributes; updating said working model with an indictor that at least one of said static connections and said subset of devices are interconnected; and, reducing said static connections in said working model to create a reduced set of static connections by removing said static connections marked with said indicator such that said applying only identifies a reverse path through said reduced set of static connections. 13. A method of claim 12, whereby said configuring further comprises querying said working model to retrieve said indicator, using said indicator to determine if a specific device, of said plurality of devices is configured to accept the information flow, and only performing said configuring if said specific device is not configured to accept the information flow. 14. A method of claim 11, further comprising: selecting a switch device from said plurality of devices, said switch device comprising a first input node, a second input node, a first output node, and a second output node, whereby at least one static connection terminates at each of said first input node and said second input node and at least one static connection terminates at each of said first output node and said second output node; selectively connecting said first input node to one of the following selected from the group consisting of said first output node, said second output node, and a termination; selectively connecting said second input node to one of the following selected from the group consisting of said first output node, said second output node and a termination; and, whereby said configuring said subset of devices is triggered by an event. 15. A method of claim 11, further comprising: grouping said subset of devices into a logical grouping stored in a database; addressing said subset of devices via said logical grouping; and, retaining configuration information for each of said subset of devices in said database. 16. A method of claim 15, further comprising: retrieving device information from said database for representing a selected device from one of said subset of devices; retrieving a device driver associated with said selected device; and, whereby said configuring said subset of devices further comprises addressing said selected device using said device information and communicating a command to said selected device using said device information and said device driver. 17. A method of claim 11, whereby said recursive algorithm is a depth first search.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>
|
<SOH> SUMMARY DISCLOSURE OF THE INVENTION <EOH>A system and method for managing and routing interconnections between devices connected via controllable switching devices and controlling the operation of the devices in a given user environment for the purpose of controlling and coordinating the operation of the user environment is presented. One embodiment of the present system and method is directed to the control of audio visual (A/V) and presentation environment control and sensing devices, and the routing and management of A/V information between generator or source devices and consumer or output devices. Source devices generate A/V data, A/V data streams, or more generally a signal that is delivered to consumer or output devices. The output devices receive the A/V data and in many cases render the A/V data in a form that is perceptible in the environment, for example one output device is a projector that would render the A/V data in a form that is visible to persons in the portion of the environment that is in proximity to the projector. The output devices are also referred to in some circumstances as consumer devices meaning that they accept information or other flows from the interconnection established with the source devices and in the case of an A/V environment they consume the A/V data. The environment where the devices, connections and other controllable devices are located is referred to generically as a user environment. A type of user environment for A/V facilities is commonly referred to as a presentation environment. The presentation environment may span several physical rooms, buildings, or even multiple locations in geographically disparate locations depending on the circumstances and use of the system. It is clear to one of ordinary skill in the art that a system for managing, routing, and controlling multiple streams of A/V data and other device communication and control signals is applicable to any system associated with an environment that requires the management, routing, and control of interconnections by and between different source devices and consumer devices as well as communication and control of a variety of devices in such environment. A non-exhaustive example of an alternative use for an embodiment of the present system and method is for a distributed data acquisition and control system whereby multiple sensors are distributed through a given facility or vehicle. The information from these sensors, such as accelerometers, are streams of data, similar in nature to a stream of A/V data. The consumers of the information generated by the sensors can be recording instruments and local feedback controllers that then actuate control lines to activate actuators that change the characteristics or states of the facility or vehicle. One embodiment of the present system and method is used to manage, route and control these streams of information generated by sensors and consumed by recording instruments and local feedback controllers as well as other control signals. In another embodiment, the present system and method is used to manage, route and control integrated building systems to provide a full spectrum of building services ranging from heating, ventilating and air conditioning through radiation management, security and fire and safety systems. In still another embodiment the system is used to route, manage interconnections and control devices in a manufacturing or chemical process facility to coordinate and control the production of various products. Although a majority of this disclosure is written in context of A/V systems and establishing connections by and between A/V devices and other discrete controllable devices to effect an A/V presentation environment, as these non-exhaustive examples show, one of ordinary skill in the art can use the present system and method for managing, routing, and controlling a variety of different types of devices and establishing connections between those devices for many different streams, including streams of A/V data, other types of signals, flows of fluids or movement of objects or products. Multiple embodiments of a system and method for controlling multiple sources and sinks of A/V data streams and controlling specific devices is presented herein. Those of ordinary skill in the art can readily use this disclosure to create alternative embodiments using the teaching contained herein. The system and method of the present invention further solves the problems associated with the configuration of multiple devices present in an arbitrary environment whereby routes or paths must be configured by and between the devices to allow information to flow from device to device through the environment while simultaneously controlling the operation of selected devices within the environment, including without limitation the operation of detached devices that effect the environment, but are otherwise not directly connected to other devices in the environment.
|
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Application No. 60/825,086, filed Sep. 8, 2006 and U.S. Application No. 60/746,290, filed May 3, 2006. BACKGROUND OF THE INVENTION Technical Field The present invention relates to a system and method for controlling, managing and routing data among multiple devices that are sources or consumers of streaming data and control devices present in a given environment in a hardware independent manner. In one embodiment, audiovisual data streams and other controllable devices in a presentation environment are controlled by the present system and method. Other embodiments of the present system and method allow the manipulation and control of controllable devices in a variety of different environments. The present invention comprises a server adapted to communicate with and command local and remote devices in an environment, enabling connections to be established between selected devices to enable the flow of information, communications or other connections to be established between the selected devices in addition to providing a means to control and communicate with other devices that influence or sense the environment. SUMMARY DISCLOSURE OF THE INVENTION A system and method for managing and routing interconnections between devices connected via controllable switching devices and controlling the operation of the devices in a given user environment for the purpose of controlling and coordinating the operation of the user environment is presented. One embodiment of the present system and method is directed to the control of audio visual (A/V) and presentation environment control and sensing devices, and the routing and management of A/V information between generator or source devices and consumer or output devices. Source devices generate A/V data, A/V data streams, or more generally a signal that is delivered to consumer or output devices. The output devices receive the A/V data and in many cases render the A/V data in a form that is perceptible in the environment, for example one output device is a projector that would render the A/V data in a form that is visible to persons in the portion of the environment that is in proximity to the projector. The output devices are also referred to in some circumstances as consumer devices meaning that they accept information or other flows from the interconnection established with the source devices and in the case of an A/V environment they consume the A/V data. The environment where the devices, connections and other controllable devices are located is referred to generically as a user environment. A type of user environment for A/V facilities is commonly referred to as a presentation environment. The presentation environment may span several physical rooms, buildings, or even multiple locations in geographically disparate locations depending on the circumstances and use of the system. It is clear to one of ordinary skill in the art that a system for managing, routing, and controlling multiple streams of A/V data and other device communication and control signals is applicable to any system associated with an environment that requires the management, routing, and control of interconnections by and between different source devices and consumer devices as well as communication and control of a variety of devices in such environment. A non-exhaustive example of an alternative use for an embodiment of the present system and method is for a distributed data acquisition and control system whereby multiple sensors are distributed through a given facility or vehicle. The information from these sensors, such as accelerometers, are streams of data, similar in nature to a stream of A/V data. The consumers of the information generated by the sensors can be recording instruments and local feedback controllers that then actuate control lines to activate actuators that change the characteristics or states of the facility or vehicle. One embodiment of the present system and method is used to manage, route and control these streams of information generated by sensors and consumed by recording instruments and local feedback controllers as well as other control signals. In another embodiment, the present system and method is used to manage, route and control integrated building systems to provide a full spectrum of building services ranging from heating, ventilating and air conditioning through radiation management, security and fire and safety systems. In still another embodiment the system is used to route, manage interconnections and control devices in a manufacturing or chemical process facility to coordinate and control the production of various products. Although a majority of this disclosure is written in context of A/V systems and establishing connections by and between A/V devices and other discrete controllable devices to effect an A/V presentation environment, as these non-exhaustive examples show, one of ordinary skill in the art can use the present system and method for managing, routing, and controlling a variety of different types of devices and establishing connections between those devices for many different streams, including streams of A/V data, other types of signals, flows of fluids or movement of objects or products. Multiple embodiments of a system and method for controlling multiple sources and sinks of A/V data streams and controlling specific devices is presented herein. Those of ordinary skill in the art can readily use this disclosure to create alternative embodiments using the teaching contained herein. The system and method of the present invention further solves the problems associated with the configuration of multiple devices present in an arbitrary environment whereby routes or paths must be configured by and between the devices to allow information to flow from device to device through the environment while simultaneously controlling the operation of selected devices within the environment, including without limitation the operation of detached devices that effect the environment, but are otherwise not directly connected to other devices in the environment. BACKGROUND ART Traditionally A/V management systems are custom designed, closed-system, hardware specific solutions designed to operate with only a limited number of hardware devices. However, the modern conference room, or media center requires the effective routing, coordination, processing, and management of multiple streams of audio visual information, or signals, generated from a variety of sources and being transferred to a wide array of different output devices or consumers of the information, generally referred to as output devices. Examples of these output devices range from projection and display systems to storage devices and external data links. An effective, open-architecture system to route, coordinate, process and manage these audio-video data streams is desirable to maximize the number of different sources and output devices required in a given environment while providing the ability to create adaptable, customized controls for sophisticated A/V systems thus enabling the creation of a highly integrated, tightly controlled presentation environment. U.S. Patent Application Publication Number US2006/0234,569 A1 to Sakamoto discloses a wireless system consisting essentially of two devices, a controlled device and a controlling device. The controlling device broadcasts a control command to identify a specific controlled device. The controlled device receives the control data and uses the discrimination code to determine which controlled device is to receive the desired command. Specifically, the patent discloses a wireless center unit, or hub, that has a variety of different input ports for a variety of A/V devices. The specific inputs used by the wireless center are selected from the controlling unit via discrimination codes that select a desired input for a given A/V device. The wireless center receives the A/V data from the source device and then converts A/V data received from the selected input port into a specified native wireless stream of A/C data for transmission to a display that is linked to the wireless center unit. The system disclosed is limited in its inability to coordinate multiple inputs and outputs across wider areas, an inability to store specific configures, inability to command external devices, lack of user settings and configuration controls, need to convert signals prior to display and a requirement for point-to-point access. Further, the system disclosed by Sakamoto only contemplates a stream of A/V data that is converted into a format specific for a single output device. Therefore, there is a need for a system for controlling multiple sources and sinks of information and that allows a plurality of different input and output devices and environmental control devices to be controlled and commanded in a uniform manner by different users through the storage and access of configuration information. U.S. Patent Application Publication Number US2003/0065,806A1 to Thomason discloses a networked system for displaying audio visual data that manages the connection between different sources to a display device to allow the display to auto-configure itself to display different types of source data. The system creates an ad hoc wireless link between the various available source devices and the display. The output device displays to the user any source devices that are available to be routed to the display device so the user may select the desired data stream to be displayed. The disclosed system is built around an ad hoc wireless network that is able to detect the existence of different source devices within range of the display device. There is no ability to establish persistent connections between different devices in the network. The disclosed system does not have any means of permissioning access to different sources and it, by default, only establishes point-to-point connections between the single display and multiple sources present in the environment. Further, the disclosed system lacks the ability to control other aspects of the environment, including the ability to control other detached devices that effect the environment that are not sources or consumers of A/V data, configure multiple devices and established routes between multiples devices located within an environment, control multiple sub-environments including output devices, nor provide for device specific rendered control interfaces for the user. Therefore, the disclosed system does not meet the need to control multiple sources and outputs of information, allow a plurality of different input and output devices to be configured and connected simultaneously, and control the environmental through separate control devices in a uniform manner by different users through the storage and access of configuration information. U.S. Patent Application Publication Number US2005/0198,040A1 to Cohen discloses a networked home entertainment system that populates a simulation model based on the available audio/visual devices in the environment. The simulation model used in the disclosed system integrates the various device states available and interfaces with various environmental controls. The home entertainment system is based around a single node or star-based network configuration. Namely all of the devices in the environment are directly linked to the central media hub that includes a digital media adaptor that operates as an interface node to all of the devices and equipment in the environment. The device states and simulation model is used to create a user interface that attempts to obscure the complexity of the system configuration from the user and purports to use a simulation agent to configure setting and enable user level control. However the disclosure lacks detail on the operation of the simulation agent and how it configures specific settings and abstracts the underlying network system from the user interface. Further, the system requires a central media hub to accept and output all of the information flowing through the environment. Thus, there is no ability to directly connect remote devices independent of the media hub, thereby limiting the ability of the disclosed system to handle complex environments with multiple sources and output devices operating simultaneously. As a result a need exists for a system and method to provide the management, routing and control of multiple devices in an environment to route signals through the environment to control and effect the configuration and operation of the environment. U.S. Pat. No. 6,850,252B1 to Hoffberg discloses an intelligent electronic appliance that models the user and attempts to adapt the user interface presented to the user during operation based on interactions with the user and the type of media content presented to the appliance. This system provides for an adaptable user interface based on the context and type of information being presented and available for the user to access, but it bases the interaction and information on the specific content of the data provided. The disclosed system fails to disclose any data specific routing for the identified data stream and performs all analysis and identification of the data stream based on the data content present within the data stream. Effectively the disclosed system samples the data stream to determine the data content present within the data stream. Then the disclosed system provides options to the user based solely on the singular device and the type of data stream available based on this sensing operation. Thus a need exists for a system capable of providing a customized user interface for the control of an environment whereby the options available to the user are provided based on the capabilities of the network and the devices in the environment and the permission levels or access levels available for a given user in the environment. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying figures depict multiple embodiments of the system and method for routing, controlling, and managing streams of data and more particularly streams of audio visual information. A brief description of each figure is provided below. Elements with the same reference numbers in each figure indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawings in which the reference number first appears. FIG. 1a is a block diagram outlining the physical architecture of an embodiment of the present system and method for audio visual (“A/V”) control and integration. FIG. 1b is diagram depicting a signal level diagram of an embodiment of an A/V system. FIG. 1c is a depiction of a control or command level diagram of an embodiment of an A/V system. FIG. 2 is a block diagram highlighting the logical components of an embodiment directed to the management, routing and control of audio visual and presentation environment control devices. FIG. 3 is a component diagram of an embodiment of the server architecture. FIG. 4 is a component diagram of an embodiment of the control client architecture. FIG. 5 is an embodiment of a first logical arrangement of a control client user interface for editing scenes. FIG. 6 is an embodiment of a second logical arrangement of a control client user interface for playing a predefined presentation. FIG. 7 is an embodiment of a third logical arrangement of a control client user interface for controlling a presentation. FIG. 8 is a rendered embodiment of a control client user interface showing the second logical arrangement. FIG. 9 is a data model of an embodiment of the system. FIG. 10 is a depiction of a control or command level diagram of a second exemplary environment. FIG. 11 is a depiction of a signal level diagram of the second exemplary environment shown in FIG. 10. FIG. 12 is a flow diagram detailing the configuration process for the system upon installation of devices in the environment or other additions of equipment to the environment. FIG. 13 is a first portion of an exemplary route map. MODES FOR CARRYING OUT THE INVENTION Audio Visual Control System Architecture FIG. 1a depicts multiple representations of an embodiment of the present system and method for audio visual control and integration in one embodiment of an exemplary physical configuration of a presentation environment 110, as shown in FIG. 1a. In this exemplary configuration, the server 100 comprises a first communication interface adapted to communicate with a remotely connected control client 102. The control client 102 is adapted to accept information from the server 100 to render or create on the control client 102 a user interface. The user interface enables a user to manage, route and control the flow of A/V data between different sources 120, output devices 130, and control or switch devices 140, and the communication and control of other detached devices or environment devices 142, not present in the routing and control of the flow of A/V data such as environment sensors and actuators that are associated with the presentation environment 110 (all collectively referred to herein as “devices” 270) located within or associated with the presentation environment 110. Although the server is shown external to the presentation environment 110 in FIG. 1a, in other embodiments the server 100 is physically located within the presentation environment 110 or provided as an integral element of one of the devices 270. Specifically, in the case of the embodiment depicted in FIG. 1a, the server 100 and the control client 102 are connected via a network 118. A network 118 as defined in this specification is any transmission medium that supports a protocol allowing communication by and between devices connected to the network as would be understood by one of ordinary skill in the art. One example of a network 118 is the Internet which utilizes the TCP/IP (Transmission Control Protocol/Internet Protocol) protocol, but the term network 118 as defined is also meant to include local access networks (LANs), wireless LANs, a multi-device serial network, and any other computer communication network, including various forms of powerline networking and X10 type networks. In still another embodiment, a first communication interface allows point-to-point communication between the server 100 and the control client 102 using a serial interface, point-to-point modem, or similar types of point-to-point communication devices and protocols known to those of ordinary skill in the art. The server 100 in this embodiment is connected via the network 118 to a communication transceiver 114, for example a terminal server. The communication transceiver 114 converts physical communication mediums and logical protocols without altering the message being carried, thereby allowing commands sent in one communications format which is suitable to the sender to be converted into another communication format suitable for the receiver. In this case a command issued by the server 100 via TCP/IP over an Ethernet network 118 is converted to the same command sent over a point-to-point RS-232/RS-485 serial link, which becomes a control signal 116 that is input to a device 270. Any communication sent from a device 270, for example an acknowledgement sent by the device 270 back to the server 110, is similarly reconverted by the communication transceiver 114. The communication transceiver 114 thus provides a second communication interface for the server 100 allowing commands and information to be exchanged between the server 100 and devices 270 associated with the presentation environment 110. In alternative embodiments, the communication transceiver 114 is eliminated and a direct communication linkage, such as a Universal Serial Bus (USB) link, is established from the server 100 to a device 270 to be controlled. In another embodiment, the server 100 communicates directly with network capable devices 270 over the computer network 118. In another embodiment, the server 100 communicates with a variety of devices 270 using a communication transceiver 114 for a subset of devices 270, direct communication for another subset of devices 270, and communication over a network 118 to yet another subset of devices 270. In still another embodiment, the server 100 communicates with the devices 270 using a wireless communication protocol, for example, infrared or visual/near-visual optical communication or radio frequency wireless protocols such as RF, Bluetooth, WiFi/802.11x, WiMax, and Zigbee and others known to those of ordinary skill in the art. In the embodiment of FIG. la, the control signals 116 output from the communication transceiver 114 are used to control multiple devices 270 including a switch 170 and second switch 158. The control signals 116 select streams of audio video data coming from a variety of sources 120 and route them to a variety of output devices 130. The switch 170 functions as an electronic patch panel that allows inputs to the switch 170 to be selectively routed or directed to selected outputs from the switch 170. In this embodiment the switch 170 supports a single type of video input, namely RGB (Red-Green-Blue color) signals, and an audio input. Source devices 120 that have RGB outputs, such as laptop computers 150, can be directly connected to the switch 170. Non-RGB sources 120 are input instead to the second switch 158. The use of a second switch 158 in this embodiment supports the various types of non-RGB signals, for example S-Video, Composite, or Component video signals from sources 120 such as a DVD 154 and a VCR 156. The outputs from the second switch 158 are then converted to RGB signals using an RGB converter 160 before being input to the switch 170. The RGB converter 160 in other embodiments can be integrated into the second switch 158. Any of these sources 120 of A/V information can be routed to any of the attached output devices 130 such as a monitor 162 or projector 164 through appropriate commands issued by the server 100 to the switch 170 and second switch 158. Other embodiments allow geographically or physically dispersed locations to be accessed and controlled from a single server 100. For example in one embodiment a transceiver 114 located in one portion of a presentation environment 110 is used to address devices 270 located in that one portion of the presentation environment 110 while the server 100 is located at a geographically remote second location that is separated from the one portion of the presentation environment 110 and only accesses the one portion of the presentation environment 110 via the transceiver 114 or direct links to the devices 270 in that one portion of the presentation environment 110. In still another alternative embodiment, high-speed data connections between locations and additional devices 270 for compressing, decompressing, and forwarding audio video and control information between locations are used to allow the physical separation of source devices 120 from output devices 130 across longer distances thus allowing geographically distributed management, routing and control of an integrated presentation environment 110 spread across a number of dispersed locations. Even in a unitary presentation environment 110, for example a presentation environment 110 comprising a number of rooms within a single building, it is common to include switching and converter equipment such as the RGB Converter 160 to transform high definition (HD) video signal signals in either analog or digital formats such as the analog Component Y/Pb/Pr format and digital High-Definition Multimedia Interface (HDMI) into other standards suitable for display on non-HD devices for example. The reverse can be implemented to support old signal formats on new HD devices. Similarly, converters for playing audio on existing audio systems 144 can also be supplied for new analog and digital audio standards and associated interfaces, including but not limited to the AC-3, Dolby® Digital® 5.1 and 7.1 standards and S/PDIF interfaces. Each of the links drawn between specific elements of the presentation environment 110 represent static connections that exist in the presentation environment 110. The topology of these static connections are stored as part of the server's 100 configuration for a given presentation environment 110 as an environment model that represents the devices 270 and other details of the presentation environment 110. The server 100 is configured with information regarding the types of connections that can be made and the equipment or devices 270 available in the presentation environment, such as one or more switches 170, that enables the server 100 to make those connections and route the information between the individual devices such as the DVD player 154 and the projector 164. The switches 170 create interconnections that associate or connect the various static connections, thereby creating a path or a linkage between devices 270 allowing them to communication by and between each other. An interconnection in some embodiments possesses attributes associated with the type of static connections that are linked together. For example a static connection linking an RGB output port from a source device 120 to a switch 170 is associated as carrying a video signal by virtue of the ports, or nodes on a given device 270 that are linked together. The specific interconnections established between devices 270 as well as the device control and the device state attributes, or device configuration, associated with a specific presentation environment 110 state are referred and stored in the server 100 as scenes. A scene thus creates a representation, or state model, of the devices 270 in the environment 110. The use of scenes to define various device states allows a user to rapidly recreate a given environment state, representing specific device states and interconnections, by retrieving a specific scene. In the embodiments of the present system and method adapted for use managing and controlling A/V environments, the term scene is used to generically describe something that in other environments might be referred to as a macro. Effectively a scene represents a group of events or commands that are issued to the devices 270, including queries of device states, necessary to configure a specific user environment in a desired manner. Similarly, a presentation, which represents groups of scenes, can be considered a grouping of macros. In the embodiment shown in FIG. 1a, the server 100 issues control signals to the communication transceiver 114 that manipulate specific devices 270 in the presentation environment 110 to create a specific room configuration or state. As part of a particular configuration of the state of the presentation environment 110, the devices 270 are manipulated to create specific routing between different source devices 120 and output device 130. Further, the control signals transferred through the communication transceiver 114 can also be sent to specific sources or source devices 120 and output devices 130 in order to configure, monitor, or control specific information associated with those source devices 120 and output devices 130. Further, control signals output from the communication transceiver 114 can also be attached to other physical actuators, sensors, or other systems such as lighting control modules or motor controls associated with projection screens and windows coverings, generically referred to as, environmental controls, environmental sensors, or environment devices 142. These environment devices are also referred to alternatively as detached devices, meaning that the devices sensor or influence the environment, but they are not a part of the routing of signals through the environment. Using these environmental controls 142, in the embodiment shown, the server 100 is capable to adjusting lighting and other aspects of the presentation environment 110. Thus, the server 100 is able to issue commands through the communication transceiver 114 to manage, route and control the flow of A/V information and actuate environment controls 142 located within specific rooms and other spaces located in the presentation environment 110 in a manner that allows the presentation environment to be readily reconfigured and controls in a variety of ways. Types of Connections For an A/V system, there are typically three types of connections to be made: Video; Audio; and, Control. The first of two of these types are the signal levels and can be grouped together on the same diagram as shown in FIG. 1b. The control or command level can be depicted separately as shown in FIG. 1c. The architecture of the present system and method allows the separation of command communication from the data or signal communication links. This separation is useful in certain circumstances to ensure that command communications are not hindered or interrupted by the flow of data in the environment. In the embodiment shown in FIG. 1b, the audio and video signal level connections are made between the different sources of video and audio information such as a webcam 180, a satellite receiver 182, a DVD player 154, a set-top box 184, or audio video data from a second switch 158, and output devices, in this FIG. 1b, there is a single consumer or output device 130, a video projector 164. The connection between these multiple sources of A/V data and the output device is through a switch 170. The control or command level schematic shown in FIG. 1c enables the server 100 to control the operation of the switch 170 and the plurality of A/V sources 120 and output devices 130 in the presentation environment 110 by passing commands through a network 118 to a communication transceiver 114 that translates the commands issued by the server into specific control signals 116 output from the communication transceiver 114 to the sources 120, output devices 130, and the switch 170. By use of a communication transceiver 114, the server 100 is abstracted from the actual physical medium or protocol used by the devices 270 for controlling the flow of signals through the presentation environment 110, such as switches 170, sources 120 and sinks 130 of information or for controlling the environment controls 142. In the embodiment shown in FIG. 1a and FIG. 1c, the communication transceiver 114 converts commands from the server 100 to device specific control signals 116. The types of control device connections can in alternative embodiments include a number of connections known to those of ordinary skill in the art including but not limited to the following exemplary connections: RS-232/RS-485 serial ports, Ethernet, Universal Serial Bus (USB), Infrared such as IrDA, RF, and other wireless connections. Although the embodiments depicted in FIG. 1a, FIG. 1b, and FIG. 1c depict a single communication transceiver 114, multiple communication transceivers 114 can be spread throughout a facility, or even multiple physically disparate locations to enable the server 100 to control multiple A/V environments with only the need to connect to them via an IP network 118 such as the Internet or company Intranet. In this manner it is possible for a single server 100, operated by a single client 102 to control a broad environment and effectively control multiple A/V presentation environments 110 in physically isolated locations and manage the experiences of people in each of those presentation environments 110. Hardware System FIG. 2 is a block diagram highlighting the logical components of one embodiment of the present system and method adapted for audio visual device management, routing and control. Specifically the present system and method is structured as client/server control application. The server application, generally referred to as the server 100, operates on a general purpose computing platform, such as a Windows or Linux platform, maintains a database 202 or other data store that stores details describing the control environment and its configuration, and issues the control commands in response to commands sent from the control client 102. The control client 102, also known as a control panel provides a means for controlling the system through a user interface, a graphical user interface or other application to enable control of devices 270 in the presentation environment 110. In some embodiments the control client 102 includes the ability to use of preset and saved system states, which are referred to as scenes and to enable groups of scenes to be presented in sequence, which are referred to as presentations. Server The server 100, provides a location for the control and storage of multiple components and elements of the present system and method. In the embodiments depicted, the server 100 is shown as a single unitary machine that can interface with multiple control clients 102 and presentation environments 110. In alternative embodiments, the server 100 can be a multiplicity of physical machines working redundantly enabling hot-swap or fail safe capabilities across a network 118 or alternatively distributing computing and processing loads. In still another embodiment, the elements of the server 100 are distributed such that individual elements or components are distributed to different locations across a network 118. In one alternative embodiment a dedicated server 100 can be used solely as a server for the database 202 that hosts the application data 204 while one or more additional servers 100 connect to the database 202 via the dedicated server 100. Server Functions Some exemplary high-level functions of an embodiment of the server 100 include: Manages users and user access. Maintains lists of all devices and their configuration settings. Maintains lists of presentation spaces or rooms and all devices available to each presentation space. Maintains all information relating to scenes and presentations. Provides control of all devices through classes and configuration information. Maintains schedules of all presentations and prevents conflicts in scheduling for all devices. In the embodiment depicted in FIG. 2, the server 100 is a computer running the Linux operating system. Although this embodiment the server is operating in a Linux based environment, a variety of different operating systems such as Windows and others can be used by one of ordinary skill in the art. The server 100 runs a web server 200 program to interface with control clients 102 to receive information and commands, provide feedback, implement the application rules necessary to run the system and perform the functions described herein, in addition to communicating with the presentation environment 110. Web Server Component The server 100 in the embodiment shown in FIG. 2 has a web server 200 for Java-based web applications, in this embodiment a Tomcat server. A Tomcat server is a Java-based web application container to run servlets and javaserver pages (JSP) for creating dynamic, web-enabled applications. Although the web server 200 shown in this embodiment is a Tomcat server, alternative methods of implementing the system and method disclosed herein are apparent to those of ordinary skill in the art. In the embodiment depicted in FIG. 2, the means for implementing the control server, shown as atmospherics.war 240 in the diagram, is deployed via the tomcat application or web server 200. Database The database 202 implements a data model 900, an embodiment of which is depicted in FIG. 9. In the embodiment depicted in FIG. 2 and FIG. 9, the database 202 is a relational database, and more specifically a PostgresSQL relational database. In alternative embodiments, the database 202 can be implemented using a multiplicity of methods known to those of ordinary skill in the art including using object-oriented or associative databases or other data structures. Regardless of the type of database 202 used, the embodiment of the data structure depicted in FIG. 9 will provide a guide as to types of information stored within the database 202. Many types of information are shown the embodiment of the data model 900 shown in FIG. 9 stored in the database 202. Some specific types of information are highlighted below: User information 902—that stores both individual user settings and preferences and works in conjunction with the access control level permissioning 904 to enable users to access specific configuration options, capabilities and system rights. User Interface Widgets 906—defines the specific user interface widget proto-elements that are linked to a device configuration and are integrated to create a set of controls and other user interface objects to be rendered on the control client 102. For example, the volume up-down element 880 can be considered an example of a user interface widget. Device configuration 908—handles information regarding the devices, including output devices and source devices and control devices to be controlled by the system and method. Device groups 910—maintains information regarding devices located in which presentation environments 110. Device connections and routing 912—holds information regarding specific physical static connections between different devices, and routing capabilities (e.g. available static connections that are physically capable in the room) that enable the server 100 to issue commands to control interconnections between source devices and output devices or issue other control device commands. Information contained within this data set is also used to restrict specific connections such as restricting the data sent to a speaker system to be only audio data or limiting the number of connections to or from a given device. The device connections and routing 912 provide an environmental model for the server 100 of the presentation environment 110 and the various devices 270 and other elements located within or associated with the presentation environment 110. Scene and presentation control 914—Stores information pertinent to a specific scene configuration or a series of different changes in system state over time, such as that embodied in a presentation where the presentation environment 110 is commanded to change state by implementing moving from one scene to another at different times, or in response to specific triggers. Event handling 916—provides controls and information for the server 100 to handle different changes in the system state, including different reporting operations and failure recovery and fault trapping details. Application Server Architecture An overview of the server application architecture 300 of the server 100 is depicted in FIG. 3. The server application architecture 300 shown in the embodiment depicted provides an overview of the interactions between different software elements comprising one embodiment of the server application architecture 300 of the system and method. The depicted embodiment details only one possible, exemplary architecture available to one of ordinary skill in the art for implementing the server application architecture 300 of the present system and method. The application service architecture 300 of the server 100 in the embodiment of the system shown in FIG. 2, is implemented within the atmospherics.war 240 component of the tomcat application server, or web server 200. The server application architecture 300 comprises a number of discrete modules. A description of a selected number of the discrete modules is provided below. Presentation Layer The presentation layer 302 provides the primary user interfaces for control clients 102 connecting to the server 100. There are three primary user interface apps, 320, 322, and 324 that generate a user interface for a given control client 102 based on the information provided by that control client 102 including the user, permission levels, presentation environment 100 and other factors. The first of the three user interface apps are a system configuration web app 324 allowing a user to configure the system. The second is the system control flash app 302 that enables a control client 102 to control devices, and create and store scenes and presentations. The third is a control phone app 320, that provides user interface specific information and controls to the control client 102 to enable it to control a phone, such as a VoIP Phone 210 and to render a control panel on a VoIP Phone 210 thereby enabling inputs by a user to a VoIP Phone 210 are able to issue control commands to the server 100 that in turn reconfigures the presentation environment 110 based on the desired inputs. The control phone app 320, although it specifically describes controlling a phone, it is obvious to one of ordinary skill in the art that other network or internet enabled devices could also be interfaced with the system via a user interface app similar in nature to the control phone app 320. Remote Communication Layer The remote communication layer 304 supports a variety of high-level services for handling communication sessions with the server 100. Application Service Layer and Others The application service 306 provides the back end processes and business logic necessary to operate the system and respond to specific system events and user inputs. The application service layer 306 works together with the component service layer 308, the domain model 310, persistence layer 312, and device control layer 314 to respond to user input provided from a control client 102 and thus allows the system to manage, route, and control multiple A/V sources and output devices as well as other devices. Within the application service 306, an event engine as described below, is used to generate, monitor and handle different actions, triggers, and changes in the system. Underlying the server application architecture 300 are multiple off-the-shelf and customized third party frameworks and libraries 316 that provide common functionality to the application service 306. Device Control Library Within the device control layer 314, a device control library 340 is provided. The device control library 340 provides interface specifics and details needed by the server 100 to interpret specific device 270 attribute information received for a given type, make and model of a device 270 and also how to structure commands suitable for the given type, make and model of the device 270 to be part of the controlled user environment. The device control library 340 in some embodiments also maintains specific details on how to communicate, monitor and respond to specific communications or responses provided by the device 270 being controlled. For example, the device control library 340 can provide details of how to structure instructions to a specific type of audio system 144 to raise and lower the volume. The same device control library 340 driver for the same audio system 144 in some embodiments also provides a monitoring function that communicates with the audio system 144 to detect faults or other problems and report the details of those respective fault events to the system for response. The contents of the device control library 340 are updateable from time to time by the user upon demand and via query to remote license and driver servers. Some exemplary types of are detached devices found in a device control library 340 adapted for use with an A/V system include environmental devices 142. Environmental devices 142 include control equipment that controls lighting in a room, including on/off switches, dimmable lighting and shades and other windows obscuring systems as well as temperature controls, power switches, and preset configuration controls. Other types of environmental devices 142 include sensors such as ambient light sensors, motion detectors, temperature sensors, humidity sensors, and switches or buttons present within the presentation environment 110. Control Client The embodiment of the control client 102, as depicted in FIG. 2, is shown as a Windows® computer and the control client 102 is implemented using a standard internet or web browser 220 running on the computer. Although the embodiment shown depicts a Windows-based client interfacing with the server 100 through a web browser, multiple other embodiments include the use of a dedicated player, such as a standalone Adobe®/Macromedia® Flash® player or a Java® applet, or other method of accepting and interpreting the information provided by the server 100, receiving input from the user, and then transferring the command and control information back to the server 100. A number of other operating systems are readily supported as known to those or ordinary skill in the art such as Windows® Mobile, Windows® CE, Mac® OS, Linux, BSD and others. By abstracting the user interface from the specifics of the control client 102, the system is able to render a user interface on a variety of different platforms running a range of different software while providing as much information and details as possible on the control client 102 relative to the capabilities of the control client 102. For example, in one embodiment, the server 100 evaluates the capabilities of the control client 102 upon log-in and then provides a customized user interface based on the ability of the control client 102 to handle the interface. In one embodiment, if the user logs into the server 100 via a handheld personal data assistant with limited display capabilities, the user interface is rendered to the control client 102 is rendered based on the details and capabilities of the personal data assistant and has possesses less information to be presented to the user. Other methods of creating a dynamic user interface on the control client 102 through communication with a server 100 can be implemented and are apparent to those of ordinary skill in the art. The control client 102 in some embodiments is a thin-client such as a Voice over Internet Protocol (VOIP) phone 210 or another closed architecture device. The server 100 communicates with the closed or proprietary architecture device local system control phone app 212 through the system control phone app 320. The user can then input commands via the VoIP phone 210 that are supplied to the server 100 to change the state of the performance environment 110 and execute scenes and other programs. In some embodiments, the control client 102 is capable of providing a customized user interface 102 for the VoIP phone 210 that enables the user to access specific functionality on the server 100 using the menus and features of the VoIP phone 210 using either a specialized sub-application running on the VoIP phone 210 or using a generalized interface for to the VoIP phone 210. System Control Client Architecture The control client 102 in the embodiment depicted in FIG. 2 can operate two client-side web applications, a client system configuration webapp 222 for configuring the server 100 and a client system control webapp 224 for controlling a given presentation, scene or presentation environment 110. Access for a user to specific features and capabilities of the system through both the client system webapp 222 and the client system control webapp 224 are limited based on the specific rights and privileges associated with a given user. Further, for some users they are unable to access the client system configuration webapp 222 at all since they have limited user privileges. System Configuration Webapp The client system configuration webapp 222 local to the control client 102 and receives information from the server 100, and more specifically the system configuration webapp 324 that it renders into a user interface for the user using a player resident on the control client 102. In the case of the embodiment depicted in FIG. 2, the player is embedded within a web browser 220. The client system configuration webapp 222 on the control client 102 renders the user interface sent from the server 100 via the system configuration webapp 324 to allow the user to configure the server 100. Some exemplary configuration actions the user can take include defining elements or devices 270 in a specific presentation environment 110, including static connections within the presentation environment 110, creating and storing device 270 and system state details, i.e. storing scenes for present or future use, or ordering multiple scenes together into a presentation, and managing users and user rights. In one example, a user who logs into the server the system configuration webapp 222 on the control client 102 who does not have sufficient privileges to modify user accounts is not presented any option to access any screens to modify user accounts by virtue of the system configuration webapp 324 not transferring details of how to render the modify user account screens to the control client 102, thus the user interface only presents details and user interface objects to the user that the user has the ability to manipulate. System Configuration Webapp Functionality The system configuration webapp 324 renders for the user on the control client 102 via the client system configuration webapp 222 and thus enabling the user to adjust several important parameters of the server 100 to effect the operation of the system. Specifically, the system configuration webapp 324 allows a user with appropriate access privileges the ability to: add and remove devices 270; provide additional details to devices 270 including device names; serial numbers; asset tag numbers; purchase details and physical location information; associate various devices 270 with specific sub-environments or rooms in the presentation environment 110; manage users; provide pointers to specific device 270 background information and details including links to external uniform resource locators (URLs) for additional documentation; and, trouble shoot problems with devices 270. Thus the system configuration webapp 324 and the client system configuration webapp 222 provide the user with the ability to customize the server 100 and thus the operation of the system. System Control Webapp The client system control webapp 224 is local to the control client 102. The architecture of the client system control webapp 224 is shown in FIG. 4, and it contains a plurality of different components that interact to provide a user of the control client 102 the ability to control devices, call-up scenes and presentations in a specific presentation environment 110. The client system control webapp 224 has multiple components to render the user interface on the control client 102. A custom skin 402 library provides visual coloring and effects to the baseline user interface control widgets that are defined by the device control user interface library, 404, and the extended device control user interface library 405. The user interface control and information widgets are used to populate the user interface framework 406 that defines the overall layout, navigation and control widget features. These interface widgets interface with the customized flash application 410, which extends the standard flash player 412, and other elements of the client system control webapp 224 to enable a user to receive feedback on system status from the server 100, and issue commands to the system. Sessions with the server 100 are handled by a server communication framework 416, while a flash remoting application 414 facilitates transferring flash content between the control client 102 and server 100. User Interface Multiple examples of a user interface on a control client 102 are presented in schematic form in FIGS. 5-7 and a single rendered form in FIG. 8. Scene Editor FIG. 5 depicts a schematic view of an embodiment of the scene editor 500 interface where a user can define a specific scene for a specific room 502 by defining the state of devices 270, in this case the device under configuration 506 is a display. Based on the specific room 502 selected by the user, a different series of device selection buttons 504 are presented to the user. For example, if a specific room 502 within the presentation environment 110, does not include any audio mixers, then the device configuration tab for audio mixers would not be rendered on a user interface, in contrast the ability to configure that device 270 provided in the scene editor 500 interface embodiment shown. Overall room controls 503 are also provided to the user so they can activate all of the systems in the room, e.g. power on and turn the volume up, down, or mute regardless of the specific devices being used. The overall room controls 503 provide a means for controlling all of the devices 270 associated with a given portion of the presentation environment 110 at the same time. This zone control allows the user to control the operations of multiple devices using a single control input. In the case of on/off controls the zone control effectively tells the server 100 to turn all of the devices 270 associated with that zone control to power up or down respectively. In the case of a graduated control, e.g. volume, the zone control provides a generalized user interface control to the user, such as a control numbered from 0 to 10. Then the zone control translates the user input on the zone control into the equivalent experienced by the device 270. For example, in one embodiment with two audio devices, one with a full scale volume input of 0-20 and the other with a full scale volume input of 0 to 100, the mapping from the single 0-10 input from the user into the others full scale range using a straightforward linear mapping. Other mapping functions can be created including logarithmic mappings or other customized mapping as required. These customized mapping functions, in some embodiments, are integrated into the device driver files and directly translate or map the user input to the device input when the configuration commands are issued to the device 270. Presentation Player FIG. 6 depicts a schematic view of an embodiment of the presentation control user interface 600. The presentation player 602 provides a user interface on the control client 102 that enables a user to select a specific presentation 604, skip either forward 606 or backward 608 from scene to scene, and play 610, pause 612 or stop 614 the presentation. The presentation control user interface 600 is showing the routing control user interface 620. The routing control user interface 620 allows a user to for a link or communication path for A/V data or signals by selecting a source device node button 622 to choose a specific a source device 120 and then selecting the type of signal to transfer using the signal routing type button 624 and selecting via the output device selection button 626 the destination or output device 130 for the A/V data. Once the user selects the type of source device 120, the signal routing type button 624 and the available output device buttons 626 change to reflect the type of signal produced by the selected source and the ability to route the signal to the output device 130 as well as the ability of the various accessible output devices 130 to accept that type of signal, which includes any converters 160 that are present in the presentation environment 110 to change the signal. The presentation control user interface 600 in some embodiments also restricts viewing of the different source devices 120 available to the user based on the type of output device 130 selected, for example when the user selects a specific projector 164, only source devices 120 capable of being routed to the selected project and capable of producing a signal usable by the projector 164 are displayed as being available for routing. When defining these routes using the routing control 620, the user is presented with the devices 270 that are available to the user based on the presentation environment 110 or room 502 they are using, their rights, and any other environment information. In one embodiment, after selecting a specific source devices 130 by selecting a source device node button 622, the route mode 624 only presents route mode information that the source device 130 and the presentation environment 110 has been configured to accept or allow. In the embodiment displayed, the signal types capable of being routed from selected via the source device node button 622 is both audio and visual data as shown in the type of available routing mode 624 displayed in the routing control 620. In this embodiment, after selecting the routing mode 624, the devices 626 that information can be routed to, based on the configuration of the room 502 and the type of data to be routed, is presented to the user to enable them to complete the routing connection. In other embodiments, the presentation environment 110 may allow multiple routes to be formed, for example from a single laptop 150 video output selected as the selected device node 622 the signal can be routed to a splitter (not shown) that splits the signal into two discrete signals. Then output from the splitter can be routed to a first projector 164 and a second projector 164 placed in another portion of the room 502. In still other alternative embodiments the routing for different types of signals can be separated, meaning that the video output of a DVD player 154 is routed to a video device such as a monitor 162 while the audio output of the DVD play erl54 is routed to the audio system 144. Presentation Selection and Editing FIG. 7 depicts a schematic view of an embodiment of a presentation definition control 700 user interface. The presentation definition control 700 user interface enables the user to select via the presentation selection interface 702 a specific presentation to access. Rendered User Interface—Presentation Player FIG. 8 depicts a rendered user interface 800 of the previously presented control user interface 600. Shown in FIG. 8 is a general volume control interface 880 that provides a zone control interface for all devices in the selected room 502 of the presentation environment 110. The presentation control user interface 600 highlights the name of the selected presentation 884 and details which scene within the presentation is currently playing via the scene selector drop down 886. The scene selector drop down 886 in this embodiment allows a user to quickly shift between different scenes within the sequence of scenes found within a presentation. Exemplary Control for Devices The following examples detail some exemplary commands and attributes for a given device 270 to be controlled by the system and stored within the device configuration 908 located within the database 202. These command and information definitions are not intended to provide exemplary instruction to one of ordinary skill in the art necessary for one to adapt this information to other systems and provide insight into how commands and user interface widgets can be abstracted from the details of the devices 270 being controlled. The following styles are used to define the device commands and attributes provided below: name=Attribute command (D)=Device command (ROA)=Read only attribute Group/Room Control These are commands and attributes that are issued to a group of rooms, or a single room, effectively as a whole. For example, if there are multiple environmental devices 142, such as light controls in a given room, the lights 260 up or down command would be issued to all of the light control devices in the room. Similarly if there are other environmental devices 142 in the form of controllable shades 266 in the room 502, the group or room control can be configured such that lowering the lights 260 in the room also draws the shades 266 to darken the room. Or alternatively if there are multiple audio sources, then a mute command would be issued to all of the audio devices 258 in the room. power=[true, false] (D) volumeUp (D) volumeDown mute=[true, false] (D) lightsup (D) lightsDown Power Power is a command that enables the system to power an individual device 270 on or off. The power command can be issued either directly to the device 270 or alternatively can be directed to a controllable power supply or distribution channel. power=[true, false] Shades 266 Shades 266 represents a type of environmental control 142 that controls window coverings. (D) Open (D) Close status=[%open] Media Player 268 A media player 268 is an arbitrary type of generalized A/V signal source or source device 120 that plays different types of media, including tape. playStatus=[play, stop, pause] (D) fastForward (D) rewind DVD Player 154 A DVD (Digital Versatile Disk) Player 154 a type of source device 120 adapted to play DVD discs and in some embodiments compact audio discs. title=[numeric value of title] chapter=[numeric value of chapter] (ROA) numberOfTitles=contains total number of titles on disc (ROA) numberOfChapters=contains total number of chapters on current title (D) nextChapter (D) previousChapter (D) menu (D) cursorUp (D) cursorDown (D) cursorLeft (D) cursorRight (D) select Display 162 Representing a general purpose output device 130 such as a television or monitor. aspectRatio=[standard, widescreen, zoom] Audio 258 An audio output device 130. mute=[true, false] volume=[numeric value of volume] Windowing Box (RGB Spectrum) The windowing box is controlling an RGB rendering tool, such as the Video to RGB converter 160 shown in FIG. 1. (D) zoomIn1, zoomIn2 . . . (as many as there are windows, inputs) (D) zoomOut1, zoomOut2 . . . (as many as there are windows, inputs) (D) up1, up2 . . . (as many as there are windows, inputs) (D) down1, down2 . . . (as many as there are windows, inputs) (D) left1, left2 . . . (as many as there are windows, inputs) (D) right1, right2 . . . (as many as there are windows, inputs) preset=[(enum) either numbers or text labels] label1, label2 (as many as there are windows)=[text field] Lighting 260 Lighting 260 represents a type of environmental device 142 or detached device present in the presentation environment 110 that effects the environment, but is detached from the signal flow established between source devices 120 and output devices 130 via any control devices 140. (D) lightsup (D) lightsDown Single Zone Control A zone is a logical grouping of nodes, elements or devices and can be large or small in number. A zone can encompass a number of presentation environments 110 or rooms 502, a set of devices 270 within a room 502, or even a number of nodes within a single device 270. (D) rampup (D) rampDown (D) stopRamp intensity=[numeric value of intensity (1-100)] power=[true, false] Multizone Control A multizone control is one that controls many zones per control unit, effectively aggregating multiple zones into a single user interface. (D) rampUp1, rampUp2 (as many as there are zones) (D) rampDown1, rampDown2 (as many as there are zones) (D) stopRamp (will stop ramping of all zones) intensity1, intensity2=[numeric value of intensity (1-100)] (as many attributes as there are zones) preset=[numeric value of preset] power=[true, false] (basically ramps all to max or all to 0) (ROA) numberOfZones=number of zones on the configured control unit Master Control Unit Control The master unit control provides a control suitable for all devices 270 or substantially all devices 270 present in a presentation environment 110 enabling commands to be issued to all devices 270 associated with the presentation environment 110. (D) rampup (D) rampDown (D) stopRamp preset=[numeric value of preset (1-16)] Other devices depicted in FIG. 2 as being controlled include video conferencing systems 262 that link multiple conference rooms together, a camera 264 for live viewing or contemporaneous recording of the room, and a Keyboard, Video, Mouse (KVM) switch 250 that can be enabled to provide a system administrator or presenter access to input devices located within a given presentation environment 110 such as a keyboard or mouse. The total number and types of devices 270 present in a given presentation environment 110 can vary significantly with a variety of different mixtures of source devices 120, output devices 130, switches or control devices 140 and detached devices or environment devices 142, including environmental sensors and actuators available for configuration, query, command and control. In the case of environment devices 142 that provide environmental information, such as ambient temperature sensors, humidity sensors, ambient light sensors, discrete input devices such as switches, and room occupancy sensors the server 100 maintains drivers capable of monitoring the information provided by these environment device 142 sensors and capturing specific events generated by these sensors for response by the system. Scalable End User Licensing One aspect of one embodiment of the system and method for audio visual control and integration is the ability for the system to scale from a small installation to larger installations. The basic licensing structure is based a base fee that includes a fixed number of servers 100, logical rooms 502, and devices 270 present within a presentation environment 110. The fixed numbers are adjustable to and in addition to the total numbers of devices 270 present the licensing and in some embodiments is keyed to the total number of specific types of devices 270, such as a total number of source devices 120, or switches/control devices 140. Additional fees are charged based on the additional rooms 502, the number of devices 270 per a room 502, and additional modules. All drivers for audio-visual hardware located in the presentation environment 110 are provided to the purchaser for a fixed period of time. After the initial period, the access to additional drivers to support the addition or substitute of other types of audio-visual hardware located in the presentation environment 110 are made available on a pay-per-installation basis or through a maintenance program. Mechanism for Achieving End User Licensing In one embodiment of the licensing system, there are two processes for allowing a given user system to access or change additional licenses or features: generating private and public keystores to enable asymmetric key encryption and then generating an actual license. The generation of keystores only needs to occur once while generating the license occurs many times, possibly for every customer. Generating License Key Stores In this one embodiment, private and public keystores are created as part of a given distribution of an embodiment of the system and method for audio visual control and integration. The keystores create both private key and public certificate files. The private key is held by the company distributing the embodiment of the system. The public certificates are used by third parties, nominally purchasers of an embodiment of the system and method for controlling, routing and managing data, who are communicating with the company to obtain additional licenses to expand, extend, or access the capabilities of the system. Generating a License File During installation of this one embodiment of the system, a license for the software is generated. When an upgrade to the capabilities of a given installation is desired, the user communicates with the company to obtain a new license. The new license enables the user to unlock the additional capabilities of the system. The license is encrypted using the private keys held by the company, and decrypted using the public keys held by the user to provide access to the additional capabilities. In this manner, it is possible for a user to upgrade the capabilities of an embodiment of the present system and method in a transparent manner. Driver Specific Licensing In addition to controlling the total quantities of devices 270, rooms 502, or servers 100 supported by a given installation, the system also enables in some embodiments the control of individual device drivers via the same licensing system. In these embodiments the same process described above for generating and encrypting the license file necessary to enable the system to operate a different levels or install additional components is used to control the distribution of specific driver files. There are two specific embodiments for protecting the driver files in this embodiment of the system and method. In the first embodiment the driver files are either transferred unencrypted from a driver server to the server 100 along with a license key adapted specifically to the driver file. The license key is unencrypted and installed in the server 100 to enable the server 100 to access and install the driver file. Without the installed key, the server 100 is unable to access and install the driver file into the device control library 340 for use by the server 100. In the second embodiment the driver files themselves are encrypted by the driver server using the driver server private key. The server 100 then decrypts the file locally using a key transferred to the server 100 to install and access the driver file into the device control library 340 for use by the server 100. In both of these embodiments, the system provides for controlled distribution of specific drivers to servers 100, these controlled distribution of specific drivers can be integrated together with the other licensing schemes described herein and known to those of ordinary skill in the art. Administration and Access Control The server 100 in one embodiment includes a three tier access control system. In the first level of access control, the system configuration controls are dedicated to those with administrative rights only and enables administrators to view and edit access control to presentations and rooms. The system configuration controls are used to control the access levels available to users, and thereby limit selections to improve usability and reduce the potential for error. The second level of access control is room-based access control. Administrators grant access to users based on who the user is or what role, or task, the user is performing. The room-based access control limits the number of rooms that a user can access by limiting the rooms visible to the user. At the room level, Administrators may specify a non-deletable main presentation that provides default settings for all presentations run in a specific room. For example, the main presentation for a given room may link multiple projectors 164 together to display the same video routed through a switch 170 from a given presentation laptop 150 input, while simultaneously setting audio 258 levels in the room and dimming the lights 260. The third level of access control in this one embodiment is presentation level access control. There are three fundamental logical access levels to presentations: none, meaning the presentation is inaccessible to a given user; read-only, meaning the presentation can be viewed or used by a given user, but cannot be modified by that user; and, full, enabling the user to modify and control the presentation in any way they wish, limited only by room-based access control prohibitions. Advanced users are able to create presentations and specify access to or share presentations with other users including the ability to provide full, or limited access to the presentations. Administrators have access to all presentations regardless of access level specified by advanced users. In still another embodiment, to seed or initialize access control levels for given users, the system communicates with an external name or user server to obtain default attributes for a given user. For example, in one embodiment, the server 100 communicates with an external name server such as a Microsoft® Exchange® server via a communication interface, such as the Lightweight Directory Access Protocol (LDAP). The server 100 retrieves base user details and attributes from the external name server via LDAP thereby allowing integration of the system with an overall enterprise architecture. Thus, the server 100 is able to update specific user customization features, such as full name, default security and access levels for the user by accessing enterprise resources, thereby simplifying maintenance of the system and providing uniformity and integration with enterprise wide information technology infrastructure. Scene Control The control client 102, in one embodiment, has the ability to edit the fine details of all devices associated with a specific scene. The control client 102, presents the user with a listing of all possible devices 270 that can be saved in a particular scene. The user can select specific devices 270, and the server 100 will save the state of the device 270 corresponding to the operation of that device 270 in the specified scene, such as volume levels for an audio device 258, along with the details of the scene. In addition to saving specific device states, the user can also retain specific routing information between devices 270 associated with a specific scene. The data corresponding to specific device 270 states and routing information is stored as application data 204 in the database 202. In this manner the user, through the control client 102, can rapidly save and restore specific routing and device configuration for reuse at a later time. Fine Grained Scene Control When specifying a scene, the user can also define events, such as when a specific action will occur, or how long a given scene is active. In this manner, the user can string multiple scenes together to form a presentation. For example in a simple case, a first scene can be used to create an opening, pre-presentation lighting and presentation environment where ambient music is piped into the room from a media player 268 and sent to an audio device 258, but there is no connection between a presentation laptop 150 and the main projector 164 enabling the presenter to ready materials and allow the audience to enter the room unhindered. When the presentation is ready to begin, a second scene is activated where the lights 260 are lowered to enhance visibility, window shades 266 are drawn, and the laptop 150 video output is connected to the projector 164 and the media player 268 is stopped. Using fine-grained scene control, a user is able to adapt a specific scene definition to only effect a subset of devices 270 located in a specific performance environment 110 necessary to change state or adopt specific setting necessary to implement the scene relative to the prior scene. In this manner, when multiple scenes are activated sequentially, for example during a presentation, or by user command, the only actions and commands sent to the devices 270 by the server 100 are those necessary to change the state of the devices 270 and the configuration of the presentation environment 110 to achieve the desired new scene configuration. Thus all other device 270 configurations and settings remaining from a prior scene that are unchanged in the new scene can be left constant. For example, at the end of a presentation a scene could be created for a question and answer period, whereby the only change from the presentation scene configuration to the question and answer configuration is to have the lights 260 raised to a desired intensity level to enable the presenter to view the audience asking questions. Using fine-grained scene control, the question and answer scene following a presentation scene would only address a single set of devices 270, namely lights 260 and all other parameters would be left unchanged from the prior scene. Fine grained scene control enables the system to transition smoothly from scene to scene. For example, if a presentation requires first lowering the light 260 and playing an introductory clip from a DVD player 154 on the projector 164 in a first scene, and then proceeding to a user presentation from a laptop 150 using the same resolution on the projector 164 with the lights 260 at the same reduced level in the next scene, then the only change to any devices 270 necessary for that scene-to-scene transition would be to change the A/V source routing to the projector 164 from the DVD player 154 to the laptop 150. The lights 260 and projector 164 would not have to be reconfigured. If the lights 260 were reset back to full on or full off before being set again to the reduced level, or the projector 164 reset, viewers could perceive a momentary flicker. Similarly, unnecessary switching or resetting of A/V sources could cause unnecessary audible clicks or pops. Therefore, only changes that represent the differences from one scene to the next scene are made thus smoothing transitions. In one embodiment, transitions from one scene to another scene in a presentation are user driven. In another embodiment, the transitions are handled by an event engine in the server 100. The event engine has an event response handler that identifies events and then switches scenes or modifies the presentation environment based on the event. For example, the event engine may wait for a user prompt before transitioning from a first scene to a second scene. Additionally, the event handler could automatically trigger the configuring of a number of presentation environments 110 at a specific time, for example to prepare a number of rooms 502 in different cities for a multi-party conference call. The event engine can also accept events triggered outside the server 100, for example a remote service call placed over a network 118 to remotely test a presentation environment 110 by a system administrator or service provider. Event Engine A component of the application service 306 is an event engine. The event engine comprises three principle components, event generators, an event monitor, and an event handler. These three components work in concert to identify specific occurrences in the environment or the system, including user inputs, and respond to those occurrences. The event engine enables the system to adapt to changes in or inputs from the environment, including the failure of specific components or devices 270. The system possesses event generators that generate internal events for the system based on specific requirements or desired occurrences. The event generators can reside and generate events from any internal service or sub-routine. Some examples of events include timers, alarms, other alerts that are generated during startup, configuration and implementation of the system and specific scenes, alerts that are triggered upon occurrence of a specific event such as a sensor exceeding a specified threshold value or another triggers that occur during operation. These internal events are passed to the event monitor for identification, recording and classification. The event monitor supervises the overall system to identify, record and classify the occurrence of specific events. These events are sequentially recorded as they emerge or are generated from the system during operation. Some events captured by the event monitor include internal events generated by the event generator, failures, errors or reporting messages received from devices 270, inputs from environmental devices, other communications and user interface inputs. The event monitor thus captures specific events occurring on the system regardless of where they are generated and passes the events to the event handler for disposition. The event monitor thus logs and in some embodiments optionally maintains a record of specific events experienced by the system during operation. The event handler processes or handles a given event that has been captured by the event monitor. The event handler determines the type of event that has occurred, determines whether it falls into a specific class of events that has a pre-defined response or if there is a unique response specific to the type of event and then triggers the appropriate sub-functions or routines necessary to respond to the event. In some circumstances the responses to given events is to change a scene as described above, other responses include notifying the user, logging the event, or performing other functions. In this manner, the event engine enables the system is able to dynamically respond to multiple occurrences or triggers found in the system and the environment. IP Phone Connectivity In one embodiment of the system and method for audio visual control and integration, there is a connection from the server to an internet protocol, or IP phone 210, also referred to as a Voice over IP (VoIP) Phone 210. The VoIP phone 210 is connected to either or both an internal and external network that can transmit voice communications and in some cases can also transmit video streams and other data. The interface to the IP Phone 210 is provided by the IP Phone Interface Component 212 that implements a logical interface with IP phones 210. The IP Phone Interface Component 212 implements an XML based schema for interfacing with a given make and model IP Phone 210, including routing information and feedback from the phone into the application service 306 as well as providing commands to the IP phone 210 itself. The flexibility of the IP Phone Interface Component 212 is the ability for the phone interface to be customized by the type of hardware being interfaced and even the room being used. For example, in one embodiment, an IP Phone manufacturer using the standards defined above, can create a highly customized, rich user interface that is presented to a person using a control client 102 that enables that person to effectively control the features and capabilities of that particular manufacturers IP Phone 210. Similarly, an administrator can control access to the features and capabilities of a given IP Phone 210 in order to achieve specific goals. For example, an administrator may restrict outgoing calls from an IP Phone 210 connected to a secure conference room to only other internal phones in order to limit potential disclosure of information. Second Exemplary Environment FIGS. 10 and 11 depict a second exemplary environment 1000 with multiple sources, outputs, switches, and detached devices. For the purposes of FIGS. 10 and 11 only, the following naming conventions is used for the figures whereby all devices and their associated interface nodes or ports are described using the key [10a#n#] where a represents the type of device 270 (s=source, o=output, i=switch or interface or flow control, and e=environment device or controls), followed by a unique number whereby s1 refers to the first source device 120. The finally two letters and number indicate whether the node is a communication node “c” or an interface node “n” followed by a unique number identifying the that node for the given device. The sources are referred to collectively as sources 10s, outputs are collectively referred to as outputs 10o, switches are collectively referred to as switches 10i, and detached device or environmental controls as controls 10e. FIG. 10 depicts a command level view of the second exemplary environment 1000 that details the command interface connections between the server 100 and the other devices 270, such as the sources 10S1-10S3, outputs 10o1-10o4, switches 10i1-10i3, and environmental controls 10e1-10e3 located within the exemplary environment 1000. FIG. 11 depicts a signal level diagram of the second exemplary environment 1000 details the physical interface between the signal ports or nodes of the sources, outputs and switches located within the exemplary environment 1000. Table I provide details of the various sources, outputs, switches and device controls in the second exemplary environment while Table II provides exemplary devices including the respective sources, outputs, switches, and device controls represent in two different applications. TABLE I Table of Sources 120, Outputs 130, Switches and Control Devices 140 Including Associated Nodes Depicted in the Second Exemplary Environment: Associated Associated Device Communication Interface Device Name ID node ID Node ID Source Device #1 10s1 s1c1 s1n1 s1n2 s1n3 Source Device #2 10s2 s2c1 s2n1 s2n2 Source Device #3 10s3 s3c1 s3n1 s3n2 s3n3 Interface Device #1 10I1 I1c1 I1n1 I1n2 I1n3 I1n4 Interface Device #2 10I2 I2c1 I2n1 I2n2 I2n3 I2n4 Interface Device #3 10I3 I3c1 I3n1 I3n2 I3n3 I3n4 I3n5 I3n6 I3n7 I3n8 Output Device #1 10D1 d1c1 d1n1 Output Device #2 10D2 d2c1 d2n1 d2n2 Output Device #3 10D3 d3c1 d3n1 d3n2 d3n3 Output Device #4 10D4 d4c1 d4n1 d4n1 Environment 10e1 e1c1 — Device #1 Environment 10e2 e2c1 — Device #2 Environment 10e3 e3c1 — Device #3 TABLE II Exemplary Devices For Audio Visual Applications or Building Systems Corresponding to the Respective Sources 120, Outputs 130, Switches and Control Devices 140 Shown in the Second Exemplary Environment: Device Exemplary Audio Exemplary Building Device Name ID Visual Devices Systems Devices Source Device #1 10s1 DVD Player 154 Chilled Water Supply Source Device #2 10s2 Satellite Fresh Air Supply Receiver 182 Source Device #3 10s3 Computer 150 Conditioned Air Supply Interface Device #1 10I1 Switch 170 Heat Exchanger Interface Device #2 10I2 Switch 170 Mixer #1 Interface Device #3 10I3 Switch 170 Mixer #2 Output Device #1 10D1 Audio Water Supply Amplifier 258 Output Device #2 10D2 Monitor 162 Room Vent #1 Output Device #3 10D3 Projector 164 Room Vent #2 Output Device #4 10D4 Projector 164 Room Vent #3 Environment 10e1 Light Light Control Device #1 Control 260 Environment 10e2 Window Shade Thermostat Device #2 Control 266 Environment 10e3 Ambient Light Humidity Sensor Device #3 Sensor Installer One embodiment of the installation system for the system and method for audio visual control and integration provides a system to enable an end user to rapidly install all of the required elements of the system for a given user installation in one single pass. The installer installs all components of the system, including, but not limited to the control language, the application server 100, and the database 202. As part of the installation sequence, the installer will configure the system to support specified hardware devices 270. Part of the installer system includes a tool or wizard interface for gathering information from the user about the presentation environment 110 to be controlled, namely providing a guided means for configuring the server 100 for the given presentation environment. In an exemplary installation, the user would define the physical rooms 502, or zones to be controlled. The user would provide the server 100 with information regarding the devices 270 available to be controlled within the room. Each device 270, can have a customized device control 506 interface for that particular type of device provided by the device driver or have a generic device control 506 interface suited for that specific type of device 270. For example, a customized device control 506 interface may be configured with specific commands to activate features of a projector 164 such as resealing, color, or brightness while a generic device control 506 interface for a light 260 simply signals a control line to switch state and turn the light on or off. Then the user configures the static connections within the presentation environment 110. The static connections define all of the connections between devices 270 that are potentially available to be controlled. Additional details on the specific configuration process to adapt and model a given presentation environment 110 or the second exemplary environment 1000 is provided below. Configuring the System The initial configuration of an arbitrary environment, such as the second exemplary environment 1000 depicted in FIGS. 10 and 11, is initiated by the installation of any or all of the devices and static connections or additions to or deletions from the devices and static connections present within the second exemplary environment 1000. The configuration of the system to control the devices present within the second exemplary environment 1000 is accomplished via either a manual configuration process or automated configuration process as described below. Manual Configuration Process The manual configuration process 1200 for the system is detailed in FIG. 12a. The manual configuration process 1200 is initiated 1202 upon either the initial installation and setup of the second exemplary environment 1000 or upon the addition or deletion of one or more a new devices or static connections between devices to the second exemplary environment 1000. For example, the manual configuration process 1200 in one case is initiated by the addition of a third source device 10s3 to the second exemplary environment 1000 and the connection of the second node of the third source device 10s3|n2 to the first node of the second interface switch 10i2|n1 thereby creating an 10s3->10i2 static connection or link between the respective nodes. For the manual configuration process 1200, the system is updated directly by manual input. In this case first the third source device 10s3 is added to the definition or representation of the second exemplary environment 1000 stored in the database 202. A device update 1204 is performed to define the devices 270 present in the environment that are part of the system, for example the device update 1204 in the case of the addition of the third source device 10s3 to the second exemplary environment 1000 would provide basic details on the third source device 10s3, such as the type, make, manufacturer, model number and other details. In yet another embodiment, where the third source device 10s3 is capable of announcing its presence in the second exemplary environment 1000 after being powered up or during initial configuration using either a standard plug-n-play or other announcement process the system receives the announcement over the server communication port 1006 that interfaces via a server communication link 1008 the system to the second exemplary environment, in some cases this communication port or communication node associated with the server 1006 is used as the server's 100 second interface to the command level network of the second exemplary environment 1000. The announcement is the equivalent of starting or initiating the device update 1204 process manually, except the update process is triggered by the announcement generated by the third source device 10s3. The server 100 receives the announcement from the new device added to the second exemplary environment 1000. The announcement generates an event that is captured by the event monitor on the application service 306. The event handler portion of the application service 306 then initiates 1202 the setup process and starts the input of device details using information provided by the third source device 10s3 as part of its announcement process. After the device update 1204 is started the newly added device, in this case the third source device 10s3, must be configured. First the server 100 performs a driver search 1206 to determine whether there exists in the system a driver definition, driver interface definition, or simply driver file appropriate for the type of installed device in the system's driver library. If the driver search locates or identifies 1208 a driver for the device to be installed, then the next step in the process is to prompt the user to gather 1210 any optional or additional device details on the installed device. Some additional details input by the user may include specific details of the installation environment, easy to remember names for the devices (e.g. Conf. Room #2 Projector) and other details as prompted by either the system itself or the device driver. If no driver definition file exists on the server 100, the system queries 1220 a driver store or remote server with multiple drivers available under a variety of different terms and conditions. The driver store in one embodiment is accessible via a wide area network such as the Internet. If a driver is available 1222, then the driver store retrieval process 1224 begins to retrieve the appropriate or requested driver for transfer to the server 100. In one embodiment the driver store retrieval process 1224 includes either encrypting the entire driver file using an asymmetric key accessible on the driver store or alternatively encrypting a token or license key to be used by the server 100 to unlock or access the driver file after download. The driver file is transferred to the server 100, and the server 100 unlocks or decrypts and installs 1226 the driver file into local driver definition file storage on the server 100. After completing the driver retrieval process 1224 and decryption and installation process 1226, the process returns to gather 1210 the device details. In another embodiment, the user manually queries a driver store and manually identifies and downloads a driver file that is provided to the system for installation directly by the user. If the driver store does not have a driver available 1222 for the device to be installed, such as the third source device 10s3, then the driver store will attempt to identify an alternative driver 1228 or default driver to use with the device to be installed. For example, in the case where the third source device 10s3 is a DVD player 154, if the driver availability 1222 shows no drive file specifically suited for the specific type of DVD player 154 to be installed in the system, then a search is conducted to identify an alternative driver 1228 to be used. In the case of the DVD player 154, a default driver might be a generalized DVD player driver that simply powers up the DVD player 154 without any additional command inputs to the third source device 10s3 command port s3c1. In some circumstances the command port, such as s3c1 does not directly command the third source device 10s3 direct, rather it simply controls a remote control switch that selectively activates or powers up the selected device. After identifying an alternative driver 1228 to be used the user is then prompted to gather 1210 device details. In the case of a generalized or generic device driver file additional information collected during the gather 1210 process in some embodiments can include specific command strings that can be issued by the server 100 in order to access specific functionality of the device to be installed, or in the embodiment depicted the third source device 10s3. The process for configuring an embodiment of the system to control an arbitrary environment begins by defining and configuring the nodes 1212 associated with or integral to specific devices 270 in the environment and establishing the static connections or links between the devices 270. In the case of the second exemplary environment 1000 each of the devices 270 located or associated with the environment, regardless whether or not the devices 270 are physically connected to the environment or only connected to the environment via a communication or other link posses at least one node, a communication node, or communication port, or command port. One sub-step of configuring the nodes 1212 or ports used by an arbitrary device 270 is to define the communications used by the system to communicate and address the device 270. In the second exemplary environment, a communication node exists for the third source device 10s3, namely the third source device 10s3 communication node s3c1. In this embodiment the third source device 10s3 communication node s3c1 is connected to a network hub 1004, this enables the server 100 to directly communicate with the third source device 10s3 via the network. The process of configuring the nodes 1212 for the third source device 10s3 communication node s3c1 in one embodiment includes defining a specific internet protocol address or network device ID for the third source device 10s3 that enables the server 100 to communicate commands and receive information from the third source device 10s3. Similarly in the second exemplary environment 1000, the first source device 10s1 undergoes the similar process of defining and configuring the nodes 1212. The first source device 10s1 possesses a first source device 10s1 communication node sic 1, which in this embodiment is a serial communication interface port. The serial port is connected to a serial port on the serial device server 1002, the serial1 node. The serial device server 1002 allows the server 100 to address the first source device 10s1 via a network interface on the server 1002 that is translated by the serial device server 1002 to serial communication via the serial1 node. Thus during the process of defining and configuring nodes 1212 and gathering 1210 device details for the first source device 10s1 and the serial device server 1002, an address for the serial device server is provided to the server 100 and the specific address or serial communication interface ports, in this example the serial1 node, is also provided to the server 100 to store in the environmental model in the database 202 thereby enabling the application service 306 to retrieve the environmental model configuration details from the system to communicate with the various devices. In a similar manner a second serial device server 1003 is addressed by the server 100. In addition to defining and configuring the nodes 1212, the communication interfaces, ports, or communication nodes are setup and associated with a given device 270. The device driver includes or in alternative embodiments with generalized drivers the user inputs details of the nodes available and associated with a given device 270 in the environment. In the case of the second exemplary environment 1000, each device 270 in the environment has a number of nodes associated with it. As described above, one of the nodes associated with a given device is the communication node that enables communication between a given device 270 and the server 100 in order to receive configuration information, transmit to the server 100 specific device-generated messages, and to otherwise accept commands from the system. The second major category of nodes associated with a device 270 is nodes that enable devices in the environment to be linked together, or link nodes. These link nodes anchor each end of a static connection or link between devices 270 in the environment. A given device 270 may have several associated nodes, however the configuration of the environment may limit the number of nodes that are actually linked together with other nodes associated with other devices 270 in the environment. Thus part of the configuration task is defining and configuring nodes 1212 and defining static connections 1214. Although the configuration flow chart shows an idealized view of the system whereby the task of defining and configuring nodes 1212 appears to precede the step of defining static connections 1214; in most embodiments though, these tasks proceed in parallel for most systems. Namely, in conjunction with defining and configuring the nodes 1212 in the environment, the static connections or links within the environment between devices 270 are also defined 1214. The device driver details for a given device 270 contain details on all of the nodes associated with that type, make, model and style of device 270. For example in the case of the third source device 10s3 depicted in FIGS. 10 and 11 of the second exemplary environment 1000, there is one third source device 10s3 command port s3c1 available for connection to the system, which as detailed above has specific capabilities and configuration details associated with a network command port. Similarly, the third source device 10s3 is associated with three interface nodes or link nodes, the first link node s3n1, second link node s3n2, and third link node s3n3. The device driver possesses the basic details of the characteristics and configurations of these interface nodes or link nodes associated with the third source device 10s3. For example, in one embodiment where the second exemplary environment 1000 is an audio-visual controlled environment where the third source device 10s3 is a DVD player 154, the first link node s3n1 is a be a stereo audio output while the second link node s3n2 is a composite video output and the third link node s3n3 is an VGA output. During the process of installing the third source device 10s3 into the second exemplary environment 1000 static connections, physical links, or simply links are established between specific nodes on the third source device 10s3 and other devices in the environment. These static interconnections reflect the actual routing of cabling or other physical or logical links established between devices 270 during installation and reflect linkages between the interface nodes that comprise the individual devices. Referring to FIG. 11 in this embodiment, a physical link or static connection established with the third source device 10s3 via the first link node s3n1 is the 10s3-10i2 link. This 10s3-10i2 link thus connects the third source device 10s3 through the first node s3n1 to the second interface device 10i2 via the second input node 10i2n2. By virtual of the physical connection established within the second exemplary environment 1000 between the devices 270 via the associated nodes on the devices it is possible to associate the nodes on both devices 270 with the ends static connection formed between the nodes as well as the devices 270 themselves. In this manner the process of defining static connections 1214 in the environment is together with gathering 1210 device details and configuring and defining and configuring nodes 1212 until all physical devices 270 and static connections in the second exemplary environment 1000 are input into the environment model. In this manner, the system develops and stores a model of the environment to be controlled within the server 100. This model of the second exemplary environment 1000 and the devices 270 available in the second exemplary environment 1000 as developed and defined in the configuration process 1200, is stored in the database 202 and used by the application service 306 to address, communication, supervise and control the devices 270. The environmental model stored 1216 within the database 202 uses the details imported from the device driver files and the details of the actual installation to model the system relative to the details of the devices 270 and interconnections between devices 270 present, in this embodiment, in the second exemplary environment 1000. The configuration process 1200 to gather 1210 device details, define and configure nodes 1212 and define static connections 1214 for a server 100 can occur during the initial installation of the server 100 for use in a given environment and can re-occur at any point in the future after the initial installation when other changes to the environment occur. These changes can range from the integration of new equipment or new capability devices 270 into the environment or loss, removal, or damage to devices 270, command links, or physical or static connections within the environment. Upon a change to the environment the configuration process 1200 is used to update the environmental model. In some embodiments, when a given device 270 is removed from the environment and is no longer available for communication the server 100, the event handler can identify the repeated failures to communicate and power up a given device 270 that is otherwise configured within the system to be present and available in the environment. In these circumstances, the server 100 uses the event details and the failure of the device 270 to temporarily remove the non-responsive device 270 and all the device's 270 associated nodes from the working model that is stored by the application service 306 during operation based on the environmental model stored in the database 202. By removing a non-responsive element from the working model used by the server 100 to operate it is possible for the system to route around the malfunctioning or non-responsive device 270 and still function at the highest level possible. Further, the system possesses the ability to prompt the user to warn them that the system has unresponsive devices 270, thereby allowing the user to reconfigure the system by removing the unresponsive devices 270 from the environmental model or to dispatch a technician to repair the unresponsive or malfunctioning device 270. In this manner, the environment model is used to maintain system configuration details from use to use and is updated using the configuration process 1200 to model all of the devices 270 in the environment and their relationship to the environment and each other. Automatic Configuration Via Import In yet another embodiment of the system, an automatic configuration process is used to import the details of the second exemplary environment 1000 or upon the addition or deletion of one or more new devices 270 or static connections between devices 270. In this yet another embodiment, a computer aided drafting (CAD) program is used to develop and design installation drawings for the devices 270 and static connections within a given environment 110. One exemplary program used to develop these drawings is VizCAD. In this embodiment of the system, an importer is used to import the details from the drawings in the CAD system into the database 202. The importer effectively performs several steps in the configuration process 1200 by automating part or all of the process for inputting device details 1204, gather 1210 device details, defining and configuring nodes 1212, and defining static connections 1214 by using the same designs and drawings created as part of the original design process for the environment and using the same information used by the technicians that configured the devices 270, the static connections and the overall environment. In one embodiment of the importer, a spreadsheet based, scripted application is developed to import design data from the CAD drawings. In one non-exhaustive embodiment Microsoft® Visual Basic for Applications (VBA) is used in conjunction with Microsoft Excel®. The drawing details are exported from the CAD program to an exported data file representing an ordered set of data representing the installed devices 270 present in the environment including any nodes associated with those devices and any static connections established between those nodes. The process starts with a CAD export process, whereby the data is exported into an intermediate structured or ordered set data file, such as a comma or tab delimited text file. The CAD export process is typically a form of a database query, such as a SQL-based query entered into an export engine native to the CAD program. This query, in one embodiment is manually entered by the user, in yet another embodiment the query is automatically retrieved from the CAD program by external query initiated by the importer. The exported data file, or files depending on the details of the particular embodiment of the importer, is used to populate three data areas of the database 202—devices 270, device groups, and static connections. The information related to devices 270, or device information, includes its unique system name, manufacturer and model, input and output nodes, and extended properties which may have been added in CAD, such as purchase date, physical location within the facility, unique identifier or asset tracking codes. Device groups identify collections of linked devices 270 that are functionally or spatially related to each other. These device groups are often in the case of an embodiment of the system used for A/V applications representative of a single room in the presentation environment 110. The information related to static connections provides the routing details for any wiring or links that connect the nodes of individual devices 270 to other nodes through the environment 110. In the case of a presentation environment 110, the routing information contains details of signal type, for example audio and video signals. In some cases, the importer abstracts additional details from the exported data file prior to import into the database 202 in order to remove or collapse specific details about the environment that the system does not or is not capable of manipulating. In one example, the video signal being carried by one embodiment of a static connection in a presentation environment 110 that is transformed from a standard VGA to an Ethernet-based signal and then back to VGA using three physical wires and one VGA-to-Ethernet and one Ethernet-to-VGA converters in order to transfer the signal over a greater distance is abstracted by the importer into a single static connection since the two converters are effectively transparent to the system. The importer abstracts or collapses these additional details during the conversion process. Specifically, the importer possesses a list of devices in a specific class, separate and distinct from the devices 270 that are controlled by the system, that provide conversion or signal boosting in the environment. In one form, these devices are simple direct input devices, meaning that they have one input node and one output node with no specifically controllable features that are addressed by the system. The no controllable features distinguishes them from other direct input devices such as windowing converters that are addressed by the system to convert a given video signal from one format (e.g. 4:3 ratio) to a second format (e.g. 16:9 ratio). The importer first identifies a connection to or from one of these simple direct input device in the data file obtained from the CAD design. When the importer locates a first simple direct input device, it then performs a search through all of the devices connected to the identified simple direct input device until it finds a matching simple direct input device. In this manner the importer logically connects and associates simple direct input devices and uses the identified relation to abstract them and eliminate them from the static connection that is imported into the system. The importer leverages the data entered into the development of the design drawings in the CAD system thereby reducing the potential for transcription errors and speeding up the initial setup and maintenance of the system. In addition to speeding the population of the database 202, the intermediate translation of the data files exported from the CAD program in the spreadsheet provides a second reference for personnel using the system to identify specific aspects and details of the system. For example a technician troubleshooting a problem or installing the system can use the spreadsheet output to verify that specific static connections between devices 270 have been properly created per the desired design. After the importer populates the database 202, the application service 306 identifies the devices 270 added to the environment and determines whether or not device drivers are available for each device 270. If a device driver is not available or the device 270 possesses additional configuration details or other configuration settings that were not represented in the CAD file the user is prompted to obtain the device driver files or enter the appropriate information for storage in the database 202. Route Mapping Once the environmental model is defined for the server 100 as part of the configuration process 1200, route map defining the full set of all possible connections and interconnections that can be established in the environment based on the available static connections, nodes associated with devices 270 and the devices 270 is created. The process of generating a route map comprising the following steps is described in relation to the second exemplary environment 1000. The server 100 evaluates all of the source nodes and destination nodes associated with the sources 10s and outputs 10o available to the server 100 in the second exemplary environment 1000. The server 100 then generates the route map by finding all of the possible routes that can be established between each respective source and destination nodes associated with the sources 10s and outputs 10o. The route map is established from each destination node, input node, or input port of each of the outputs 10o, such as the output device 10o1, to any of the possible output ports or output nodes of the sources 10s that can supply the desired or appropriate types of signal, data, streams, or flows for the input nodes associated with the destination output device 10o1. The generation of the route map for a given presentation environment 110 is typically performed only when the server 100 is initially configured for the second exemplary environment 1000 or after changes have occurred. These route maps associated with a given environment 110, such as the second exemplary environment 1000 with its multiple interface devices 10i-10i3 respectively, are created by the system during initialization. This enables the system to determine whether or not all devices 270 in the environment 110 are responding to device commands prior to using the devices 270 as part of the available presentation route maps in a given environment. These route maps represent the physical effect of the specific configuration and capabilities of devices 270 installed in the environment as manifest within the environmental model. The route maps in one embodiment are represented as series of tree like structures that travel up the static connections or links between specific outputs 10o to connect to available sources 10s. Referring to the exemplary tree link maps in FIG. 13, all possible reverse paths between outputs 10o and sources 10s are represented within the route map. A first portion 1310 of a route map details all of the reverse links between the second output device 10d2 that link or form a connection with any of the sources 10s shown as reverse links. Each of the arrows in the first portion 1310 of a route map represents a static connection or link between singular nodes established within the second exemplary environment 1000 connecting one node to another. Nodes that have multiple connections between themselves and other nodes indicate that a selectable connection or link exists, such as that found in switches 10i. The first portion 1310 of a route map is formed for each of the outputs 10o by stepping through each and every connection from the node under consideration that leads to source nodes. In the case of an audio visual system, the route map is only formed ‘upstream’ meaning that connections are only followed in the opposite direction to the data flow—meaning in the case of an audio-visual system the route map is established in an anti-sense direction from the output device 130 to the input or source device 120. In this manner the route map is used to populate trees that detail all available links between sources 10s and outputs 10o from node to node. This then allows the routes to be represented as shown in FIG. 13 in the first portion 1310 of a route map After generating the route map all operations required by the server 100 prior to performing routing operations to form connections between sources 10s and outputs 10o in the second exemplary environment 1000 are completed. In one embodiment the route map is formed during the initial startup of the server 100 using the environmental model stored in the database 202. The route map is then loaded into a working model of the environment that is then manipulated during operation of the server 100 by the application service 306. In a second embodiment, the basis of initial route map is also stored in the database 202 for retrieval during startup to populate the working model of the environment used by the application service 306 during operation of the system. In both cases the working model of the environment is updated from the time-to-time during normal operation in response to changes in the server 100, including removing devices 270 from the working model due to events that have occurred or removing specific routes available based on other routes that are implemented as part of a scene being applied to the environment. Intelligent Routing Engine The intelligent routing engine or simply the routing algorithm is comprised of multiple discrete functions that operate together to identify routes and connections between sources 10s and outputs 10o suitable for the type of information or type of flow to be transferred or accommodated within and through the environment. The routing algorithm is implemented within the web server 200, within the application service 306, that is physically hosted on the server 100. The routing algorithm utilizes both dynamic (i.e. working model) and static (e.g. environmental model) application data 204 that is stored in the database 202 to create, identify, and establish valid connections between sources 10s outputs 10o located in an environment such as the second exemplary environment 1000. The Routing Algorithm is implemented as a functional element of the server 100 and is used during both initial configuration of the server 100 to establish initial routes when implementing a desired scene or whenever a new configuration of connections from a given source to a given output is required during operation. The routing algorithm operates on the working model of the environment described above. The working model itself is derived from the environmental model established with the configuration 1200 process and stored in the database 202. Thus the routing algorithm identifies routes or paths through the environment for flows using the information and details input into the server 100 during the configuration 1200 process. Prior to starting the routing algorithm an environmental model and working model of the environment are created. The configuration 1200 process provides the environmental model with details of all the devices and specifics related to those devices 270 present within a given environment, including the communication and interface nodes associated with those devices and the respective static connections or links that connect the interface nodes between and within discrete devices 270 such as the sources 10s, outputs 10o and switches 10i. The working model of the environment reflects the current state or status of the server 100, including the present states or configurations of each individual device 270 located in the second exemplary environment 1000 including controls 10e. The working model of the environment thus effectively represents a full state model, or configuration model of an arbitrary environment whereby static connections, device 270 details, and dynamic details (e.g. the linking or switching of two interface nodes in a switch 10i to select a specific path through the switch and link the respective static connections that terminate at interface nodes associated with the switch 10i) of the environment at a given time. The routing algorithm uses the working model to establish new connections or links between devices 270 located in the environment comprising a number of static connections or links along with the nodes that terminate each of the static connections and the devices 270 that are associated with those nodes. When a route is established each node along the path is effectively associated with two separate elements of the system, first the device 270 the node is associated with originally and the node is also associated with the route or link it is part of that is established through the environment to link a desired source 10s with a desired output 10o. The working model utilizes a routing map to reflects all available routes and connections that may be established in an environment. The routing algorithm uses the routing map and the respective trees representations of the routing maps, to determine available routes or paths between selected devices 270. When a specific pair of devices 270 is selected to be interconnected in the interface layer or data layer either by the user directly during operation of the server 100 by inputting a desired pair of devices 270 to be connected through the user interface of the control client 102 or while implementing a new scene, the routing algorithm is used to determine the proper configuration or state for the system to adopt to accomplish the desired outcome. When the server 100 is initially starting up, and the environment is unconfigured and the devices are ready, but no routes or paths through the environment have been created, the routing algorithm is applied to a first pair of devices 270 to be connected within the environment and it determines the proper route, in other words the routing algorithm identifies the configuration of devices 270, including the device's associated nodes, and static connections interconnecting the associated nodes in order to create a path between the devices 270. The resulting path updates the working model of the environment to reflect the fact that a portion of the system within the environment is now dedicated to establishing a desired link between the sources 10s and the outputs 10o. By dedicating some links in the environment to this first route, there is an effective reduction in the total number of available routes and the application service 306 updates the working model to reflect this reduction in potential routes and the new states of the devices 270 implicated by the newly established route. The newly establish route is then queued for implementation in the environment via the server 100 issuing configuration commands to the devices 270 in the environment to establish the route that the algorithm has identified. During startup, the next pairing of devices 270 is used to establish a second route and so on until all pairs of devices are either connected or the system generates an event indicating to the user that the desired configuration cannot be created or another event occurs to interrupt the process. A similar process is used to generate a route when a new pair of connections is desired after a scene is already implemented. For example if the system is already configured in a particular state to implement a specific scene, the working model holds the device states to implement that scene. Upon shifting to a new scene the application service 306 updates the working model on the server 100 to reflect any presently configured routes that are no longer needed in the new scene and proceeds to form any new routes required by the new scene. The routing algorithm is applied to the working model to determine the desired device 270 states to implement the new routes required by the new scene. The intelligent routing algorithm, or simply routing algorithm uses a recursive algorithm to traverse the available nodes and static connections or links available to traverse across the system from the desired output 10o to the desired source 10s. In this manner the routing algorithm identifies a desired path through the environment comprising at least the desired source 10s and desired output 10o device and at least one nodes associated with each of those sources 10s and outputs 10o and the static connections that terminate with those respective nodes. In one embodiment of the system a recursive algorithm is used to traverse the routing maps to identify the desired route. Different embodiments of the routing algorithm use different types of search routines, including the following recursive search algorithms: breadth-first search, depth limited search, A*, Dijkstra's algorithm, best-first search, and dynamic programming generally. Alternative algorithms including non-recursive and non-traditional algorithms are available for use by those of ordinary skill in the art. In one embodiment of the system a recursive depth first search algorithm is used to traverse the routing tree starting with the output 10o device. The output 10o device is effectively the root of the tree. There can be one or more input nodes or input ports associated with the output 10o device. If the desired input is capable of providing signals that can be accepted by any of the input nodes associated with the desired output 10o device, then all possible input nodes associated with the output device in the environment are considered, otherwise only the reduced number of input nodes associated with the output 10o device are considered. The routing algorithm starts with the selected output 10o device and evaluates any static connections available from input nodes associated with the selected output 10o device that it then traverses or 'travels' away from the output 10o toward the source 10s. The depth first search algorithm prioritizes driving directly toward the goal of the source device at the expense of potential dead-end routes. Thus the routing algorithm travels along the static connection that terminates at the input node associated with the output 10o device to the other terminating node of the static connection. The other terminating node of the selected static connection is associated with a second device 270 in the environment, including switches 10i, sources 10s, and in some embodiments other outputs 10o. The algorithm then evaluates the other nodes associated with this second device in the environment that are able to switch and connect with the present node to determine whether any of the nodes offer the ability to leave the second device and continue toward the desired destination, namely the desired source 10s. If another node associated with second device exists that terminates a second static connection, the routing algorithm follows this path to the node associated with the other terminus of the second static connection and the third device associated with the that node. In this manner the routing algorithm follows the static connections through each connection's terminating nodes and the associated devices to the desired source 10s. The same process is repeated for each node associated with a given device until either a route to the desired source 10s is identified or a dead-end is found, meaning there are no available connections to follow away from a non-desired device. Upon identifying a dead-end, the algorithm returns to the immediately prior device and evaluates the next unevaluated node available on the immediately prior device until there are no remaining unevaluated nodes on the immediately prior device, at which point the algorithm considers the next prior device. If after traversing all of the connections traveling away from the output 10o and being unable to identify a route to the desired source 10s, the routing algorithm will determine that no route is available and report the error via an event trigger. If the algorithm is successful in identifying a route to the desired source 10s, the routing algorithm reports back the desired configuration of static connections, nodes that terminate the static connections, and the devices that are associated with the nodes to be configured in order to create the desired route through the environment. The reported route, including devices and associated nodes to be configured is then marked within the working model to indicate that the reported route, including all nodes and associated devices along the route are included in the identified route and no longer available for other routes, and the working model properly reflect the dedication of a portion of the environment to route. The identified route is then passed to the application service 306 that issues the commands using the environment model and device driver details to the devices 270 and the associated nodes to establish the route in the second exemplary environment 1000. INDUSTRIAL APPLICABILITY Control of Multiple Audio Visual Components The present system and method disclosed herein in embodiments for use with presentation environments 110 possesses a multiple capabilities to perform a plurality tasks. Specifically the system and method enables the management of complex connections between the devices, including sources and output devices 270 of A/V data and enables the control of devices, including sources and output devices 270 of A/V data and other presentation environment 110 environmental devices 142 without requiring full configuration paths for all the equipment. Second, the system and method auto-generates user interfaces with appropriate controls for a given presentation environment 110 based on the types of devices 270 and environmental devices 142 available. Third the system and method enables control of specific scenes and presentation control to allow complex multitasking and integration of multiple devices 270 and controls 142 to act in concert with a mere press of a button to configure a presentation environment 110. The self-generating user interface enables the server 100 to connect with a variety of different control clients 102, including those that have never connected to a particular environment before, and provide a user interface tailored for the presentation environment 110 to be controlled. Finally, since the system and method is based on a client server architecture with access and communication through standard computer networks, such as IP based networks like the Internet, the server 100 can be located in any geographic location with no impact on the control of a given presentation environment 110 thus enabling centralized management, portability, transportability, and consistent user interface across an entire enterprise. These specific capabilities enabled by embodiments of the present system and method and others inherent within the system and method disclosed are obvious to one of ordinary skill in the art and this listing is merely provided as a non-exhaustive set of examples. Control of Integrated Building Systems Yet another exemplary application of the present system for managing, routing and controlling devices in an environment is to control the various devices 270, environmental devices 142 present in an integrated building. In this application the system is used to direct the operation of specific devices 270 in the environment, including sources 10s such as chillers to produce cool air or a dehumidifier that reduces the relative humidity content of air present in a heating ventilation and air conditioning (HVAC) system. The system directs the operation of the sources 10sto generate conditioned air, then various switches 10i, or flow control devices such as controllable dampers and mixers are used to mix and distribute the conditioned air through a system of physical connections, static connections, or more generally links present the environment (e.g. ducts or pipes) for distribution to specific output devices located in the areas to accept the conditioned air. The effect of the distribution of the conditioned air is then monitored by communication with environmental device 142 sensors located in the environment that monitor the environment. In a similar manner the system is able to connect the environment devices 142 actuators present in the environment to change the overall characteristics of the building, such as adjusting lighting in response to ambient light sensors or automatically dimming windows in response to direct sunlight. Similar control can be applied other building systems, including security, fire and safety and other building systems. Control of Flexible Manufacturing and Process Equipment In still another exemplary embodiment, the present system for managing, routing and controlling devices is used to control systems and equipment present in a flexible manufacturing facility or chemical process facility. In a flexible manufacturing environment there are multiple devices that are classified as sources 10s capable of generating a partial or fully completed product or intermediary product. These sources 10s need commands to provide or start their respective process of generating product. The resulting product then is routed between other devices 270, that can simultaneously operate as both consumer devices or outputs 10o and sources 10s—namely by accepting partially completed product, performing additional operations, and then outputting the transformed product to another output 10o. In this manner the system treats the source 10s, outputs 10s, and combined source and output devices present in a facility as any other sources 10s to be controlled and the product is routed between the devices by commanding switches 10i manifest as switching equipment, pipe valves, diverters, flexible conveyor belts or semi-autonomous skillets to establish connections or links between the desired sources 10s and consumer or output 10o devices and establish links to route the product between devices. In a similar manner, various sensors for detecting and evaluating the quality of the product provides feedback to the system during operation allowing corrective action to be taken if necessary. In a manufacturing environment sensors environment devices 142 include: temperature sensor, pressure sensor, flow-rate sensor, accelerometer, humidity sensor, radio frequency identification tag reader, finger-print scanner, optical scanner, proximity detector, spectrometer, load sensor, force sensor, and ultrasonic sensor. CONCLUSION While various embodiments of the present system and method for controlling devices and environments have been described above, it should be understood that the embodiments have been presented by the way of example only, and not limitation. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined. Thus, the breadth and scope of the present invention should not be limited by any of the above described exemplary embodiments.
|
H
|
H04
|
H04L
|
9
|
00
|
|||
11697779
|
US20070190694A1-20070816
|
INTEGRATED CIRCUIT PACKAGE WITH LEADFRAME LOCKED ENCAPSULATION AND METHOD OF MANUFACTURE THEREFOR
|
ACCEPTED
|
20070801
|
20070816
|
[]
|
H01L2100
|
["H01L2100"]
|
7413933
|
20070409
|
20080819
|
438
|
123000
|
72874.0
|
HOANG
|
QUOC
|
[{"inventor_name_last": "Punzalan", "inventor_name_first": "Jeffrey", "inventor_city": "Singapore", "inventor_state": "", "inventor_country": "SG"}, {"inventor_name_last": "Ku", "inventor_name_first": "Jae Hun", "inventor_city": "Singapore", "inventor_state": "", "inventor_country": "SG"}, {"inventor_name_last": "Han", "inventor_name_first": "Byung Joon", "inventor_city": "Singapore", "inventor_state": "", "inventor_country": "SG"}]
|
A semiconductor including a leadframe having a die attach paddle and a number of leads is provided. The die attach paddle has a recess to provide a number of mold dams around the periphery of the die attach paddle. An integrated circuit is positioned in the recess. Electrical connections between the integrated circuit and the number of leads are made, and an encapsulant is formed over the integrated circuit and around the number of mold dams.
|
1. A method of manufacturing a semiconductor comprising: providing a leadframe having a die attach paddle and a number of leads; forming a recess in the die attach paddle to provide a number of mold dams around the periphery of the die attach paddle; positioning an integrated circuit in the recess; forming electrical connections between the integrated circuit and the number of leads; and forming an encapsulant over the integrated circuit and around the number of mold dams. 2. The method of manufacturing a semiconductor as claimed in claim 1 wherein forming a recess in the die attach paddle forms a recess about fifty-five percent of the way through the die attach paddle. 3. The method of manufacturing a semiconductor as claimed in claim 1 wherein providing a number of mold dams around the periphery of the die attach paddle provides the number of mold dams in a position of at least one of at the corners of the die attach paddle, intermediate the corners of the die attach paddle, and combinations thereof. 4. The method of manufacturing a semiconductor as claimed in claim 1 wherein forming an encapsulant flows the encapsulant into the spaces between the mold dams and over the integrated circuit. 5. The method of manufacturing a semiconductor as claimed in claim 1 wherein forming the encapsulant forms at least one of plastic, epoxy, ceramic, and combinations thereof. 6. A method of manufacturing a semiconductor comprising: providing a leadframe having a die attach paddle and a number of leads; etching a recess at least half way into the die attach paddle to provide a number of mold dams around the periphery of the die attach paddle; bonding an integrated circuit in the recess; wire bonding electrical connections between the integrated circuit and the number of leads; and forming an encapsulant over the integrated circuit and around the number of mold dams. 7. The method of manufacturing a semiconductor as claimed in claim 6 wherein forming a recess into the die attach paddle forms a recess about fifty-five percent of the way through the die attach paddle. 8. The method of manufacturing a semiconductor as claimed in claim 6 wherein providing a number of mold dams around the periphery of the die attach paddle provides the number of mold dams in a position of at least one of at the corners of the die attach paddle, intermediate the comers of the die attach paddle, and combinations thereof. 9. The method of manufacturing a semiconductor as claimed in claim 6 wherein forming an encapsulant flows the encapsulant into the spaces between the mold dams and over the integrated circuit. 10. The method of manufacturing a semiconductor as claimed in claim 6 wherein forming the encapsulant forms an encapsulant of at least one of plastic, epoxy, ceramic, and combinations thereof. 11. A semiconductor comprising: a leadframe having a die attach paddle and a number of leads; the die attach paddle having a recess to provide a number of mold dams around the periphery of the die attach paddle; an integrated circuit in the recess; electrical connections between the integrated circuit and the number of leads; and an encapsulant over the integrated circuit and around the number of mold dams. 12. The semiconductor as claimed in claim 11 wherein the recess in the die attach paddle is about fifty-five percent of the way through the die attach paddle. 13. The semiconductor as claimed in claim 11 wherein the number of mold dams is positioned in at least one of at the corners of the die attach paddle, intermediate the corners of the die attach paddle, and combinations thereof. 14. The semiconductor as claimed in claim 11 wherein the encapsulant substantially fills the spaces between the number of mold dams. 15. The semiconductor as claimed in claim 11 wherein the encapsulant comprises at least one of plastic, epoxy, ceramic, and combinations thereof. 16. A semiconductor comprising: a leadframe having a die attach paddle and a number of leads; the die attach paddle having a recess at least half way into the die attach paddle to provide a number of mold dams around the periphery of the die attach paddle; an integrated circuit in the recess; electrical connections between the integrated circuit and the number of leads; and an encapsulant over the integrated circuit and around the number of mold dams. 17. The semiconductor as claimed in claim 16 wherein the recess into the die attach paddle is about fifty-five percent of the way through the die attach paddle. 18. The semiconductor as claimed in claim 16 wherein the number of mold dams around the periphery of the die attach paddle is positioned in at least one of at the corners of the die attach paddle, intermediate the comers of the die attach paddle, and combinations thereof. 19. The semiconductor as claimed in claim 16 wherein the encapsulant substantially fills the spaces between the mold dams. 20. The semiconductor as claimed in claim 16 wherein the encapsulant comprises an encapsulant of at least one of plastic, epoxy, ceramic, and combinations thereof.
|
<SOH> BACKGROUND ART <EOH>In the electronics industry, the continuing goal has been to reduce the size of electronic devices such as camcorders and portable telephones while increasing performance and speed. Integrated circuit packages for complex systems typically are comprised of a multiplicity of interconnected integrated circuit chips. The integrated circuit chips usually are made from a semiconductor material such as silicon or gallium arsenide. Semiconductor devices are formed in the various layers of the integrated circuit chips using photolithographic techniques. The integrated circuit chips may be mounted in packages that are then mounted on printed wiring boards. Packages including integrated circuit chips typically have numerous external pins that are mechanically attached by solder or a variety of other known techniques to conductor patterns on the printed wiring board. Typically, the packages on which these integrated semiconductor chips are mounted include a substrate or other chip mounting device. One example of such a substrate is a leadframe. High performance leadframes typically are multi-layer structures including power, ground, and signal planes. Leadframes also typically include at least an area on which an integrated circuit chip is mounted and a plurality of power, ground, and/or signal leads to which power, ground, and/or signal sites of the integrated semiconductor chip are electronically attached. Semiconductor integrated chips may be attached to the leadframe using adhesive or any other techniques for attaching such chips to a leadframe which are commonly known to those skilled in the art, such as soldering. The power, ground and signal sites on the chip may then be electrically connected to selected power, ground and signal plane or individual leads of the leadframe. Leadframes have been used extensively in the integrated circuit (IC) packaging industry mainly because of their low manufacturing cost and high reliability. Leadframe packages remain a cost-effective solution for packaging integrated circuits despite the introduction of various leadless packages in recent years. Typical leadframe packages include a die attach paddle, or pad, surrounded by a number of leads. An integrated circuit chip, is attached to the die attach paddle using a conductive adhesive such as silver epoxy. The conductive adhesive is cured after die attach. After the die is attached to the die paddle, a wire-bonding process is used to make electrical interconnections between the integrated circuit and the leads of the leadframe. After wire bonding, the leadframe with the integrated circuit attached is encapsulated using a molding compound. Such enclosures may include encapsulation in a plastic or a multi-part housing made of plastic ceramic, or metal. The enclosure protects the leadframe and the attached chip from physical, electrical, and/or chemical damage. Finally, post mold curing and singulation steps are conducted to complete the packaging process. The leadframe and attached chip(s) may then be mounted on, for example, a circuit board, or card along with other leadframes or devices. The circuit board or card may then be incorporated into a wide variety of devices such as computers, automobiles, or appliances, among others. One problem that persists with leadframes is that the integrated circuits mounted on these leadframes are subject to failure due to moisture penetration of the integrated circuit package. If the molding compound is not securely attached to the leadframe, moisture or other contaminants can contact the integrated circuit thereby causing failures. Another problem is that the molding compound does not flow evenly over the entire leadframe resulting in areas where moisture or other contaminants may contact the integrated circuit thereby contributing to the failure of the integrated circuit. Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.
|
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIG. 1 is a partial cross-sectional view of a leadframe in an intermediate stage of manufacture in accordance with the present invention; FIG. 2 is the structure of FIG. 1 after processing of a mask on the surface of the leadframe; FIG. 3 is the structure of FIG. 2 after an etch process to form a die paddle; FIG. 4 is the structure of FIG. 3 after an integrated circuit is attached to the die paddle of the leadframe; FIG. 5 is the structure of FIG. 4 after encapsulation of the integrated circuit; FIG. 6 is a plan view of the structure of FIG. 5 manufactured in accordance with the present invention without an encapsulant; FIG. 7 is a plan view of another embodiment of a leadframe having four mold dams manufactured in accordance with the present invention; and FIG. 8 is a flow chart of a method for manufacturing a leadframe in accordance with the present invention. detailed-description description="Detailed Description" end="lead"?
|
CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/478,433 filed Jun. 12, 2003, and the subject matter thereof is hereby incorporated herein by reference thereto. This application is a continuation of U.S. Non Provisional Patent Application Ser. No. 10/850,220 filed May 19, 2004. TECHNICAL FIELD The present invention relates generally to semiconductor technology, and more particularly to a method and apparatus for an integrated circuit leadframe package. BACKGROUND ART In the electronics industry, the continuing goal has been to reduce the size of electronic devices such as camcorders and portable telephones while increasing performance and speed. Integrated circuit packages for complex systems typically are comprised of a multiplicity of interconnected integrated circuit chips. The integrated circuit chips usually are made from a semiconductor material such as silicon or gallium arsenide. Semiconductor devices are formed in the various layers of the integrated circuit chips using photolithographic techniques. The integrated circuit chips may be mounted in packages that are then mounted on printed wiring boards. Packages including integrated circuit chips typically have numerous external pins that are mechanically attached by solder or a variety of other known techniques to conductor patterns on the printed wiring board. Typically, the packages on which these integrated semiconductor chips are mounted include a substrate or other chip mounting device. One example of such a substrate is a leadframe. High performance leadframes typically are multi-layer structures including power, ground, and signal planes. Leadframes also typically include at least an area on which an integrated circuit chip is mounted and a plurality of power, ground, and/or signal leads to which power, ground, and/or signal sites of the integrated semiconductor chip are electronically attached. Semiconductor integrated chips may be attached to the leadframe using adhesive or any other techniques for attaching such chips to a leadframe which are commonly known to those skilled in the art, such as soldering. The power, ground and signal sites on the chip may then be electrically connected to selected power, ground and signal plane or individual leads of the leadframe. Leadframes have been used extensively in the integrated circuit (IC) packaging industry mainly because of their low manufacturing cost and high reliability. Leadframe packages remain a cost-effective solution for packaging integrated circuits despite the introduction of various leadless packages in recent years. Typical leadframe packages include a die attach paddle, or pad, surrounded by a number of leads. An integrated circuit chip, is attached to the die attach paddle using a conductive adhesive such as silver epoxy. The conductive adhesive is cured after die attach. After the die is attached to the die paddle, a wire-bonding process is used to make electrical interconnections between the integrated circuit and the leads of the leadframe. After wire bonding, the leadframe with the integrated circuit attached is encapsulated using a molding compound. Such enclosures may include encapsulation in a plastic or a multi-part housing made of plastic ceramic, or metal. The enclosure protects the leadframe and the attached chip from physical, electrical, and/or chemical damage. Finally, post mold curing and singulation steps are conducted to complete the packaging process. The leadframe and attached chip(s) may then be mounted on, for example, a circuit board, or card along with other leadframes or devices. The circuit board or card may then be incorporated into a wide variety of devices such as computers, automobiles, or appliances, among others. One problem that persists with leadframes is that the integrated circuits mounted on these leadframes are subject to failure due to moisture penetration of the integrated circuit package. If the molding compound is not securely attached to the leadframe, moisture or other contaminants can contact the integrated circuit thereby causing failures. Another problem is that the molding compound does not flow evenly over the entire leadframe resulting in areas where moisture or other contaminants may contact the integrated circuit thereby contributing to the failure of the integrated circuit. Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art. DISCLOSURE OF THE INVENTION The present invention provides a semiconductor including a leadframe having a die attach paddle and a number of leads. The die attach paddle has a recess to provide a number of mold dams around the periphery of the die attach paddle. An integrated circuit is positioned in the recess. Electrical connections between the integrated circuit and the number of leads are made, and an encapsulant is formed over the integrated circuit and around the number of mold dams. The present invention reduces failure of semiconductors due to moisture penetration of the integrated circuit package. The molding compound is attached more securely to the leadframe so moisture or other contaminants cannot contact the integrated circuit thereby causing failures. Also, the molding compound flows evenly reducing the areas where moisture or other contaminants may contact the integrated circuit thereby reducing the failure of the integrated circuit. Certain embodiments of the invention have other advantages in addition to or in place of those mentioned above. The advantages will become apparent to those skilled in the art from a reading of the following detailed description when taken with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial cross-sectional view of a leadframe in an intermediate stage of manufacture in accordance with the present invention; FIG. 2 is the structure of FIG. 1 after processing of a mask on the surface of the leadframe; FIG. 3 is the structure of FIG. 2 after an etch process to form a die paddle; FIG. 4 is the structure of FIG. 3 after an integrated circuit is attached to the die paddle of the leadframe; FIG. 5 is the structure of FIG. 4 after encapsulation of the integrated circuit; FIG. 6 is a plan view of the structure of FIG. 5 manufactured in accordance with the present invention without an encapsulant; FIG. 7 is a plan view of another embodiment of a leadframe having four mold dams manufactured in accordance with the present invention; and FIG. 8 is a flow chart of a method for manufacturing a leadframe in accordance with the present invention. BEST MODE FOR CARRYING OUT THE INVENTION In the following description, numerous specific details are given to provide a thorough understanding of the invention. However, it will be apparent that the invention may be practiced without these specific details. In order to avoid obscuring the present invention, some well-known system configurations, and process steps are not disclosed in detail. Likewise, the drawings showing embodiments of the present invention are semi-diagrammatic and not to scale and, particularly, some of the dimensions are for the clarity of presentation and are shown exaggerated in the FIGs. The term “horizontal” as used herein is defined as a plane parallel to the conventional plane or surface of the leadframe, regardless of its orientation. The term “vertical” refers to a direction perpendicular to the horizontal as just defined. Terms, such as “on”, “above”, “below”, “bottom”, “top”, “side” (as in “sidewall”), “higher”, “lower”, “over”, and “under”, are defined with respect to the horizontal plane. The term “processing” as used herein includes deposition of material or photoresist, patterning, exposure, development, etching, cleaning, and/or removal of the material or photoresist as required in forming a described structure. Referring now to FIG. 1, therein is shown a partial cross-sectional view of a semiconductor 100 in an intermediate stage of manufacture in accordance with the present invention. The semiconductor 100 includes a leadframe 102. The leadframe has an upper surface 104 and a lower surface 106. Referring now to FIG. 2, therein is shown the structure of FIG. 1 after processing to form a mask 200 on the upper surface 104 of the leadframe 102. The mask 200 is formed by depositing a layer of photoresist 202 on the upper surface 104 of the leadframe 102 and processing the layer of photoresist 202 to form the mask 200. Referring now to FIG. 3, therein is shown the structure of FIG. 2 after an etch process 300 has been performed on the upper surface 104 of the leadframe 102 using the mask 200. The leadframe 102 is etched using the mask 200 to form a die attach paddle 302 and a number of leads 304 surrounding the die attach paddle 302. A recess 308 is formed in the leadframe 102 by etching only partially through the leadframe 102 to form a number of mold dams 310 in the die attach paddle 302. The recess 308 is formed interior to the peripheral areas of the die attach paddle 302. It has been discovered that etching the die paddle 302 of the leadframe 102 to about fifty-five percent (55%) of the thickness of the die paddle 302 to form the recess 308 results in providing suitable thickness for the number of mold dams 310 while maintaining the stiffness of the die paddle 302. Referring now to FIG. 4, therein is shown the structure of FIG. 3 after an integrated circuit 400 is attached to the die paddle 302 of the leadframe 102. The mask 200 shown in FIG. 3 has been removed. A bonding compound 402, such as an epoxy, has been deposited in the recess 308 in the die attach paddle 302. The integrated circuit 400 is positioned on the die attach paddle 302 to be bonded by the bonding compound 402. When the recess 308 is sufficiently deep, the integrated circuit 400 will be positioned partially below the upper surface 104 of the die attach paddle 302 and surrounded by the number of mold dams 310. The integrated circuit 400 is therefore locked in position by the number of mold dams 310 to provide additional stability for the integrated circuit 400. Referring now to FIG. 5, therein is shown the structure of FIG. 4 after encapsulation of the integrated circuit 400. The integrated circuit 400 is electrically connected to the number of leads 304 using a number of bonding wires 500. An encapsulant 502, such as plastic, epoxy, ceramic, or other suitable material, is formed over the integrated circuit 400, the number of bonding wires 500, and a portion of the number of leads 304. The encapsulant 502 also fills the space between the number of leads 304 and the die attach paddle 302. During the encapsulation process, a mold (not shown) is used to direct the flow of the encapsulant 502 into any spaces between the mold dams 310 thereby providing a locking mechanism for the encapsulant 502. It is therefore more difficult for the encapsulant 502 to pull away from the die attach paddle 302 or the integrated circuit 400 thereby enhancing the integrity and stability of the semiconductor 100. Moisture or other contaminants cannot as easily penetrate the semiconductor 100. Referring now to FIG. 6, therein is shown a plan view of the structure of FIG. 5 without the encapsulant 502 having the number of mold dams 310 manufactured in accordance with the present invention. The leadframe 102 includes the die attach paddle 302 and the number of leads 304 surrounding the die attach paddle 302. The die attach paddle 302 has been processed to form the number of mold dams 310 around the periphery of the die attach paddle 302 and the recess in the die attach paddle 302. The bonding compound 402 shown in FIG. 5 is deposited on the die attach paddle 302. The integrated circuit 400 is positioned over the bonding compound 402 to attach the integrated circuit 400 to the die attach paddle 302. The encapsulant 502 fills the spaces between the mold dams 310 to provide the locking mechanism for locking the encapsulant 502 and the die attach paddle 302. An edge 600 is formed during a singulation process after the semiconductor is encapsulated. Referring now to FIG. 7 therein is shown a plan view of another embodiment of the semiconductor 100 having four mold dams 310 manufactured in accordance with the present invention. The number of mold dams 310 is formed at each corner of the die attach paddle 302 to form four mold dams. It will be apparent to those skilled in the art that a particular semiconductor may have any number of mold dams 310 depending upon the design requirements for a particular semiconductor. The encapsulant 502 fills the spaces between the mold dams 310 to provide the locking mechanism for locking the encapsulant 502 and the die attach paddle 302. An edge 700 is formed during a singulation process after the semiconductor is encapsulated. Referring now to FIG. 8 therein is shown a flow chart of a method 800 for manufacturing a semiconductor in accordance with the present invention. The method 800 includes providing a leadframe having a die attach paddle and a number of leads in a block 802; forming a recess in the die attach paddle to provide a number of mold dams around the periphery of the die attach paddle in a block 804; positioning an integrated circuit in the recess in a block 806; forming electrical connections between the integrated circuit and the number of leads in a block 808; and forming an encapsulant over the integrated circuit and around the number of mold dams in a block 810. Thus, it has been discovered that the method and apparatus of the present invention furnish important and heretofore unavailable solutions, capabilities, and functional advantages for the manufacture of semiconductors. The resulting process and configurations are straightforward, economical, uncomplicated, highly versatile, and effective, use conventional technologies, and are thus readily suited for manufacturing semiconductor devices and are fully compatible with conventional manufacturing processes and technologies. While the invention has been described in conjunction with a specific best mode, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the scope of the included claims. All matters set forth herein or shown in the accompanying drawings are to be interpreted in an illustrative and non-limiting sense.
|
H
|
H01
|
H01L
|
21
|
00
|
|||
11939570
|
US20090124144A1-20090514
|
System for Steering and Maneuvering a Watercraft Propelled by a Water Jet
|
ACCEPTED
|
20090429
|
20090514
|
[]
|
B63H11107
|
["B63H11107"]
|
7874883
|
20071114
|
20110125
|
440
|
042000
|
96021.0
|
SWINEHART
|
EDWIN
|
[{"inventor_name_last": "Rui", "inventor_name_first": "Yuting", "inventor_city": "Ann Arbor", "inventor_state": "MI", "inventor_country": "US"}]
|
A system for steering a watercraft propelled by a water jet includes a control lever supported to pivot rightward and leftward about a first axis, a nozzle supported on the watercraft to pivot rightward and leftward and through which water is discharged from the watercraft, first and second cables, and a steering module interconnected by the cables to the control lever and connected to the nozzle, supported to pivot laterally about a second axis and to pivot the nozzle laterally in response to pivoting of the control lever about the first axis.
|
1. A system for steering a watercraft propelled by a water jet comprising: a control lever supported to pivot rightward and leftward about a first axis; a nozzle through which the water jet is discharged from the watercraft, the nozzle being supported to pivot rightward and leftward; first and second cables; a forward disc connected to the control lever and supported to rotate about the first axis with the control lever, secured to a first end of the first cable eccentric of the first axis, and secured to a first end of the second cable eccentric of the first axis; a rear disc driveably connected to the nozzle and supported to rotate about a second axis, secured to a second end of the first cable eccentric of the second axis, and secured to a second end of the second cable eccentric of the second axis, and directing the water jet laterally in response to movement of the control lever about the first axis. 2. The system of claim 1 wherein; the rear disc module directs the nozzle leftward in response to rightward movement of the control lever about the first axis; and the rear disc module directs the nozzle rightward in response to leftward movement of the control lever about the first axis. 3. The system of claim 1 further comprising: a hull; and a bracket secured to the hull, providing the first axis, and providing a third axis about which the control lever pivots upward and downward. 4. The system of claim 1 further comprising: a mechanism for transmitting rotation of the rear disc to the nozzle including a first pin concentric with the second axis and secured to the rear disc for rotation therewith, a second bracket secured to the nozzle, and a second pin extending radially from the first pin and engaged with the second bracket eccentric of the second axis. 5. The system of claim 1 wherein the nozzle pivots rightward and leftward about a fourth axis that is offset from the second axis. 6. A system for steering a watercraft propelled by a water jet comprising: a control lever supported to pivot rightward and leftward about a first axis; a nozzle through which the water jet is discharged from the watercraft, the nozzle being supported to pivot rightward and leftward; first and second cables; a steering module interconnected by the cables to the control lever, connected to the nozzle, and supported to rotate about a second axis, for directing the water jet laterally in response to movement of the control lever about the first axis. 7. The system of claim 6 wherein; the steering module directs the nozzle leftward in response to rightward movement of the control lever about the first axis; and the steering module directs the nozzle rightward in response to leftward movement of the control lever about the first axis. 8. The system of claim 6 further comprising: a hull; and a bracket secured to the hull, providing the first axis, and providing a third axis about which the control lever pivots upward and downward. 9. The system of claim 6 further comprising: a forward disc connected to the control lever and supported to rotate about the first axis with the control lever, secured to a first end of the first cable eccentric of the first axis, and secured to a first end of the second cable eccentric of the first axis; and wherein the steering module further comprises a rear disc driveably connected to the nozzle and supported to rotate about the second axis, secured to a second end of the first cable eccentric of the second axis, and secured to a second end of the second cable eccentric of the second axis. 10. The system of claim 6 further comprising: a forward disc connected to the control lever and supported to rotate about the first axis with the control lever, secured to a first end of the first cable at a first angular position about the first axis and eccentric of the first axis, and secured to a first end of the second cable eccentric of the first axis and at a second angular position about the first axis that is offset angularly from the first position; and wherein the steering module further comprises a rear disc driveably connected to the nozzle and supported to rotate about the second axis, secured to a second end of the first cable at a first angular position about the second axis and eccentric of the second axis, and secured to a second end of the second cable eccentric of the second axis and at a second angular position about the second axis that is offset angularly from the first position. 11. The system of claim 6 wherein the steering module further comprises: a rear disc driveably connected to the nozzle and supported to rotate about the second axis, secured to a second end of the first cable eccentric of the second axis, and secured to a second end of the second cable eccentric of the second axis; and a mechanism for transmitting rotation of the rear disc to the nozzle including a first pin concentric with the second axis and secured to the rear disc for rotation therewith, a second bracket secured to the nozzle, and a second pin extending radially from the first pin and engaged with the second bracket eccentric of the second axis. 12. The system of claim 6 wherein the nozzle pivots rightward and leftward about a fourth axis that is offset from the second axis. 13. A system for steering a watercraft propelled by a water jet comprising: a control lever supported to pivot rightward and leftward about a first axis; a nozzle through which the water jet is discharged from the watercraft, the nozzle being supported to pivot rightward and leftward; a forward disc connected to the control lever and supported to rotate about the first axis as the control lever pivots; and a rear disc supported to rotate about a second axis, driveably connected to the nozzle and forward disc such that the rear disc and nozzle rotate leftward in response to rightward movement of the control lever about the first axis, and rightward in response to leftward movement of the control lever about the first axis, rotation of the rear disc directing the water jet laterally in response to movement of the control lever about the first axis. 14. The system of claim 13 further comprising: a first connector including a first end and a second end; a second connector including a first end and a second end, the forward disc being secured to the first end of the first connector eccentric of the first axis and secured to the first end of the second connector eccentric of the first axis, the rear disc being secured to the second end of the first connector eccentric of the second axis and secured to the second end of the second connector eccentric of the second axis. 15. The system of claim 13 wherein the steering module further comprises: a mechanism for transmitting rotation of the rear disc to the nozzle including a first pin concentric with the second axis and secured to the rear disc for rotation therewith, a second bracket secured to the nozzle, and a second pin extending radially from the first pin and engaged with the second bracket eccentric of the second axis. 16. The system of claim 13 wherein the nozzle pivots rightward and leftward about a third axis that is offset from the second axis. 17. The system of claim 13 further comprising: a hull; and a bracket secured to the hull, providing the first axis, and providing a fourth axis, about which the control lever pivots upward and downward.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates generally to a boat propelled by a water jet. In particular, the invention pertains to a kayak-like watercraft that is steered and maneuvered by directing a nozzle through which the water jet is discharged. 2. Description of the Prior Art A jet-boat is a boat propelled by a jet of water ejected from the back of the craft. Unlike a powerboat or motorboat that uses a propeller in the water behind the boat, a jet-boat draws the water from under the boat into a pump-jet inside the boat, then expels the injected water through a nozzle at the stern. Jet-boats are steered and maneuvered by directing the nozzle and water jet laterally from the longitudinal axis of the craft, such that the water jet both propels and steers the craft. Jet boats can be reversed and brought to a stop within a short distance from full speed using the jet. A conventional screw impeller accelerates a large volume of water by a small amount, similar to the way an airplane's propeller accelerates a large volume of air by a small amount. In a jet-boat, pumping a small volume of water, accelerating it by a large amount, and expelling the water above the water line delivers thrust that propels the craft. Acceleration of the water is achieved by the impeller driven by a small ICE onboard the craft.
|
<SOH> SUMMARY OF THE INVENTION <EOH>A system for steering a watercraft propelled by a water jet includes a control lever supported to pivot rightward and leftward about a first axis, a nozzle supported on the watercraft to pivot rightward and leftward and through which water is discharged from the watercraft, first and second cables, and a steering module interconnected by the cables to the control lever and connected to the nozzle, supported to pivot laterally about a second axis and to pivot the nozzle laterally in response to pivoting of the control lever about the first axis. The rider sits on the upper deck of the boat's hull with legs extended along the deck and straddling the control lever. The control lever is simple and intuitive to operate and is conveniently located within easy reach of the rider. The control lever can be stowed away when the craft is being stored or transported. An accelerator for adjusting engine speed and starting and stopping the engine are located on the control lever. The craft is steered and maneuvered by pivoting the control lever rightward and leftward, thereby causing the nozzle to pivot and direct the water jet in a direction that causes the watercraft to turn in the direction that the lever is pivoted. The control lever and its interconnection to the nozzle are direct and reliable, has few moving parts, is of low cost, and can be installed and assembled easily. The scope of applicability of the preferred embodiment will become apparent from the following detailed description, claims and drawings. It should be understood, that the description and specific examples, although indicating preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications to the described embodiments and examples will become apparent to those skilled in the art.
|
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to a boat propelled by a water jet. In particular, the invention pertains to a kayak-like watercraft that is steered and maneuvered by directing a nozzle through which the water jet is discharged. 2. Description of the Prior Art A jet-boat is a boat propelled by a jet of water ejected from the back of the craft. Unlike a powerboat or motorboat that uses a propeller in the water behind the boat, a jet-boat draws the water from under the boat into a pump-jet inside the boat, then expels the injected water through a nozzle at the stern. Jet-boats are steered and maneuvered by directing the nozzle and water jet laterally from the longitudinal axis of the craft, such that the water jet both propels and steers the craft. Jet boats can be reversed and brought to a stop within a short distance from full speed using the jet. A conventional screw impeller accelerates a large volume of water by a small amount, similar to the way an airplane's propeller accelerates a large volume of air by a small amount. In a jet-boat, pumping a small volume of water, accelerating it by a large amount, and expelling the water above the water line delivers thrust that propels the craft. Acceleration of the water is achieved by the impeller driven by a small ICE onboard the craft. SUMMARY OF THE INVENTION A system for steering a watercraft propelled by a water jet includes a control lever supported to pivot rightward and leftward about a first axis, a nozzle supported on the watercraft to pivot rightward and leftward and through which water is discharged from the watercraft, first and second cables, and a steering module interconnected by the cables to the control lever and connected to the nozzle, supported to pivot laterally about a second axis and to pivot the nozzle laterally in response to pivoting of the control lever about the first axis. The rider sits on the upper deck of the boat's hull with legs extended along the deck and straddling the control lever. The control lever is simple and intuitive to operate and is conveniently located within easy reach of the rider. The control lever can be stowed away when the craft is being stored or transported. An accelerator for adjusting engine speed and starting and stopping the engine are located on the control lever. The craft is steered and maneuvered by pivoting the control lever rightward and leftward, thereby causing the nozzle to pivot and direct the water jet in a direction that causes the watercraft to turn in the direction that the lever is pivoted. The control lever and its interconnection to the nozzle are direct and reliable, has few moving parts, is of low cost, and can be installed and assembled easily. The scope of applicability of the preferred embodiment will become apparent from the following detailed description, claims and drawings. It should be understood, that the description and specific examples, although indicating preferred embodiments of the invention, are given by way of illustration only. Various changes and modifications to the described embodiments and examples will become apparent to those skilled in the art. DESCRIPTION OF THE DRAWINGS The invention will be more readily understood by reference to the following description, taken with the accompanying drawings, in which: FIG. 1 is a cross-sectional side view of an engine-powered kayak showing the water induction system and engine; FIG. 2 is schematic top view of the steering system; FIG. 3 is a side view partially in cross section showing the control lever and a forward steering module; FIG. 4 is a top view, partially in cross section, of the control level shown in FIG. 3; FIG. 5 is a side cross sectional view showing the rear steering module and nozzle aligned with the longitudinal axis of the craft; and FIG. 6 is an end cross sectional view showing the rear steering module and nozzle disposed as shown in FIG. 5. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, a kayak 10 includes a sealed hull portion 12 covered with a seamless molded plastic skin, the hull being formed with a recess 14 on its upper surface 15, in which recess the rider sits facing forward with legs straddling a manually-operated control lever 16 (called a joystick) and feet supported on foot rests. The volume of hull 12 between its upper deck 15 and its bottom surface 17 is filled with a core material 20 that reinforces, strengthens and stiffens the hull. The core 20 may be expandable, cellular molded foam or a hollow, hexangular honeycomb whose walls are of Kevlar or a similar synthetic material. Alternatively, the core may be formed of machined foam. The hull portion 12 is sealed, thereby preventing entry of water from waves or spray and making it possible to roll the kayak upright again following a tip over without it filling with water. A seat back 22, secured to the upper surface of the hull 12 supports the seated rider. The core-reinforced portion of the hull 12 is closed by a partition or bulkhead 24, located at the forward end of an engine compartment 26, which contains an engine 28, water intake duct 30, bladed impeller 32 that forces water from the intake duct, and a nozzle 34, whose angular position about a vertical axis can be varied leftward and rightward to steer the kayak 10. Water inducted through duct 30 flows through the impeller and exits through the nozzle 34. The engine compartment 26 is covered with a cowling 36 formed with an air inlet passageway 38. Cowling 36 is secured by latches to the upper surface of the hull, thereby sealing the engine compartment against entry of water when the cowling is latched to the hull. Preferably, engine 28 has a single cylinder and piston, low displacement and operates at high efficiency on a four stroke cycle. The intake duct 30, which may be a component separate from the hull 12 or formed integrally with the hull, is of molded plastic having an intake opening 44 in the bottom of the hull, through which water is inducted and flows toward the outlet of nozzle 34. A driveshaft 46, secured to the crankshaft 47 of engine 28 drives the bladed impeller 32 in rotation, thereby drawing water into the intake duct 30 and forcing it through the impeller and out the nozzle 34. A water jet, which propels and steers the kayak 10, rises from the outlet of nozzle 34 into the air above the water surface. The rider pivots the joystick 16 leftward and rightward about axis 48 to steer the craft 10. The joystick 16 carries a button 50, which is depressed to start engine 28, a button 52 that stops the engine, and an engine throttle in the form of a trigger 64 located on the underside of the joystick, by which the engine throttle is opened and closed to control engine speed and the speed of the kayak 10. The rider also pivots the joystick 16 upward and downward about axis 49 to locate its hand grip in a comfortable position during use and in a downward position when the craft 10 is stored or being transported. As control lever 16 pivots rightward and leftward about axis 48, cables 54, 56 transmit movement of the lever 16 to the nozzle 34, which pivots leftward and rightward, respectively, in response to movement of the lever, thereby steering and maneuvering the kayak 10 by redirecting the water jet exiting the nozzle rightward and leftward relative to the longitudinal axis of the craft. Cables 54, 56 may be similar to the type used manually to actuate the brakes of a bike. FIGS. 2 and 3 show that the hand grip 66 of control lever 16 carries a extension 68, which is attached by a bolt fitted into a central hole 70 and engaged with a support 72, which supports lever 16. Support 72 is secured to a bracket 74, which is fixed at bolt holes 75 to the surface of the upper deck 15 of the hull 12. Support 72 provides the axis 49, about which control lever 16 pivots upward and downward. Support 72 also pivots about axis 48 as the rider applies lateral force to control lever 16 to steer the kayak 10. A forward rotary disc 76, seated in a recess 78 formed in support 72, 5 pivots about axis 48 in response to pivoting of lever 16. One end of cable 56 enters a laterally passageway 80, formed in support 72, and is secured at 82 to the rotary disc 76. One end of cable 54 enters a laterally passageway 84, formed in support 72, and is secured at 86 to the rotary disc 76. Cables 54, 56 are preferably constructed of twisted strands of steel encased in a plastic tube, which supports the 10 cables against compression instability when a compressive force is applied to the steel strands. When control lever 66 pivots clockwise as seen in FIGS. 2 and 4, tension force is applied to cable 54 and compression force is applied to cable 56 as rotary disc 76 rotates about axis 48. When control lever 66 pivots counterclockwise as seen in FIGS. 2 and 4, tension force is applied to cable 56 and compression force is applied to cable 54 as disc 76 rotates about axis 48. FIGS. 5 and 6 show a steering control module 90 connected to the opposite ends of cables 54, 56 for directing nozzle 34 laterally in response to movement of the control lever 16. A support 92 is secured to a bracket 94, which is fixed at bolt holes 95 to the surface of the upper deck 15 of the hull 12. A cover 95 closes the upper surface of support 92. A rear rotary disc 96, seated in a recess 98 formed in support 92, pivots about a vertical axis 100 in response to pivoting of lever 16. The opposite end of cable 56 from the end that is attached to forward disc 76 enters a laterally passageway 102, formed in support 92, and is secured at 104 to the rear disc 96. The opposite end of cable 54 from the end that attaches to disc 76 enters a laterally passageway 106, formed in support 72, and is secured at 108 to the rear rotary disc 76. A pin 110 is fitted into holes aligned with axis 100 and formed in cover 95, support 92, disc 96 and bracket 94. The lower end of pin 110 is formed with a lateral hole that is engaged by a lateral pin 114. Pin 110 is formed with a shoulder 126, which is fitted in a hole 128 in disc 96, thereby fixing pin 110 and disc 96 mutually for rotation as a unit about axis 100. An angle bracket 116 includes a vertical leg 118 having a hole that is engaged by pin 114, and a horizontal leg 120 secured by two screws 122, 123 to the upper surface 124 of nozzle 34. A transverse pin 130, such as a cotter pin, passes through pin 114 and prevents inadvertent disconnection of bracket 116 from pin 110. When control lever 16 pivots clockwise about first axis 48, as seen in FIGS. 2 and 4, tension force applied to cable 54 is transmitted to rear disc 96, thereby causing disc 96, pin 110 and pin 114 to rotate counterclockwise about axis 100. As pin 114 rotates, bracket 116 rotates counterclockwise forcing nozzle 34 to turn counterclockwise about axis 110, thereby directing the water jet exiting the nozzle 34 rightward causing the kayak to turn rightward, i.e., in the same direction as the control lever 16 is pivoted by the rider. Nozzle 34 is supported at 132 for rotation about an axis 134, which may be aligned with axis 100 or eccentric of axis 100. When control lever 66 pivots counterclockwise about first axis 48, as shown in FIGS. 2 and 4, tension force applied to cable 56 is transmitted to rear disc 96 causing disc 96, pin 110 and pin 114 to rotate clockwise about axis 100. As pin 114 rotates clockwise, bracket 116 rotates clockwise forcing nozzle 34 to turn clockwise, thereby directing the water jet exiting the nozzle 34 to the left and causing the kayak to turn to the left, i.e., in the same direction as the control lever 16 is pivoted by the rider. Preferably pin 114 and bracket 116 are made from stainless steel, and support 92 is made from ABS reinforced with 20 percent fiber glass by volume. Cables 54, 56 may be replaced by any suitable connectors able to transmit movement of the control lever 16 to the rear disc 96 including, but not limited to connecting rods, ropes and wires. In accordance with the provisions of the patent statutes, the preferred embodiment has been described. However, it should be noted that the alternate embodiments can be practiced otherwise than as specifically illustrated and described.
|
B
|
B63
|
B63H
|
111
|
07
|
|||
11759736
|
US20070285103A1-20071213
|
Electronic Package and Method for Testing the Same
|
ACCEPTED
|
20071128
|
20071213
|
[]
|
G01R3108
|
["G01R3108"]
|
7408362
|
20070607
|
20080805
|
324
|
527000
|
94040.0
|
NGUYEN
|
VINCENT
|
[{"inventor_name_last": "Ahmad", "inventor_name_first": "Shakil", "inventor_city": "Singapore", "inventor_state": "", "inventor_country": "SG"}, {"inventor_name_last": "Kang", "inventor_name_first": "Poh", "inventor_city": "Singapore", "inventor_state": "", "inventor_country": "SG"}, {"inventor_name_last": "Singh", "inventor_name_first": "Narang", "inventor_city": "Singapore", "inventor_state": "", "inventor_country": "SG"}]
|
An integrated circuit package includes at least two electronic circuits. A first of the at least two electronic circuits includes a digital input and a digital output and a test mode control line for setting the first integrated circuit chip into a determined test mode. The digital input includes at least two parallel input paths and the digital output includes at least two parallel output paths. The at least two parallel input paths and at least two parallel output paths provide a corresponding number of internal paths by which the first electronic circuit and a second electronic circuit can be tested essentially simultaneously.
|
1. An electronic package, comprising: a first electronic circuit configurable in a test mode, the first electronic circuit including: a digital input with first and second parallel input paths; and a digital output with first and second parallel output paths; at least one second electronic circuit configurable in a test mode; and an input/output path digitally coupling the first electronic circuit to the second electronic circuit; wherein the first electronic circuit, in the test mode, is configured to: direct data received at the first parallel input path to the second electronic circuit via the input/output path; direct data received from the second electronic circuit via the input/output path to the first parallel output path; process data received at the second parallel input path; and direct the processed data to the second parallel output path; and wherein the second electronic circuit, in the test mode, is configured to process the data received at the input/output path from the first electronic circuit and to direct the processed data to the first electronic circuit via the input/output path. 2. The electronic package according to claim 1, wherein data received from the second parallel input path is processed in the first electronic circuit at the same time as the data received from the first parallel data path is processed in the second electronic circuit. 3. The electronic package according to claim 1, wherein the first and second electronic circuits are electronic chips. 4. The electronic package according to claim 1, wherein the second electronic circuit further comprises an analog module with an analog input/output path. 5. The electronic package according to claim 1, wherein the first electronic circuit further comprises a data separating device operable to separate data received at the digital input into data to be processed by the second electronic circuit and into data to be processed by the first electronic circuit. 6. A method for electronically testing an electronic package including first and second electronic circuits, the method comprising: connecting a digital input, a digital output, an analog input, and an analog output of the electronic package to an electronic testing device, the digital input including first and second input paths, the digital output including first and second output paths; providing for each of the first and second electronic circuits a test pattern including an input test pattern to be applied to the electronic circuit and a corresponding expected output test pattern resulting from processing the input test pattern; producing test data comprising a merged test pattern by merging respective lines of the test patterns of the first and second electronic circuits such that individual lines of the merged test pattern include lines from the respective test patterns of the first and second electronic circuits; applying each line of the merged test pattern to the first and second input paths; setting the first and second electronic circuits into a predetermined test mode, wherein the first electronic circuit: directs the test data received at the first input path to the second electronic circuit; directs the test data received from the second electric circuit to the first output path; processes test data received at the second input path; and directs the processed test data to the second output path, wherein processing of the test data in the first circuit and in the second circuit is performed essentially in parallel; evaluating the output; comparing output signals received from the first and second output paths with the expected output pattern; and determining whether the output signals deviate from the expected output pattern. 7. The method according to claim 6, wherein NOP instructions are written into one part of the merged test pattern corresponding to respective lines of the test pattern of one of the electronic circuits in the event respective lines of the test pattern of one of the first and second electronic circuit no longer comprises valid test operation instructions and the other of the first and second electronic circuits still comprises valid test operation instructions.
|
<SOH> BACKGROUND <EOH>After a semiconductor chip has been manufactured, it undergoes a testing sequence to determine if the chip is functioning correctly. The testing can be performed using an automatic test pattern generation (ATPG) technique in which an ATPG pattern is generated specifically to test the functionality of this particular type of chip. However, this technique has the disadvantage that the ATPG patterns are large and the time required to test the chip is quite long. This problem is exacerbated in Multi-Chip Modules (MCM) and System-In-Package (SIP) components which include two or more chips to be tested. The long testing times required ultimately increase the cost of producing the chip or module. Large test patterns also require a larger tester memory to store the patterns. Therefore, the tester resources required is increased and also increases complexity and the total cost of testing and manufacturing the chip or module.
|
<SOH> SUMMARY <EOH>Methods of testing a Multi-Chip Module which avoid the problems associated with the known testing techniques, reduce the required testing time and, therefore, the cost of manufacturing the module are described herein. Furthermore, a semiconductor package which includes at least two electronic circuits is also described herein, in particular a semiconductor package with at least two chips providing a multi-chip module. In this description, the phrase semiconductor package is used to denote a Multi-Chip Module or System-In-Package electronic component. A first of the at least two electronic circuits includes a digital input and a digital output and a test mode control line for setting the first semiconductor chip into a determined test mode. The digital input includes at least two parallel input paths and the digital output includes at least two parallel output paths. The at least two parallel input paths and at least two parallel output paths provide a corresponding number of internal paths by which the first electronic circuit and a second electronic circuit can be tested at essentially the same time. The above and still further features and advantages of the present invention will become apparent upon consideration of the following definitions, descriptions and descriptive figures of specific embodiments thereof, wherein like reference numerals in the various figures are utilized to designate like components. While these descriptions go into specific details of the invention, it should be understood that variations may and do exist and would be apparent to those skilled in the art based on the descriptions herein.
|
CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Application No. PCT/IB2004/004021, filed on Dec. 7, 2004, entitled “Test Time Reduction for Multi-Chip Modules (MCM) and for System-In-Packages (SIP),” the entire contents of which are hereby incorporated by reference. BACKGROUND After a semiconductor chip has been manufactured, it undergoes a testing sequence to determine if the chip is functioning correctly. The testing can be performed using an automatic test pattern generation (ATPG) technique in which an ATPG pattern is generated specifically to test the functionality of this particular type of chip. However, this technique has the disadvantage that the ATPG patterns are large and the time required to test the chip is quite long. This problem is exacerbated in Multi-Chip Modules (MCM) and System-In-Package (SIP) components which include two or more chips to be tested. The long testing times required ultimately increase the cost of producing the chip or module. Large test patterns also require a larger tester memory to store the patterns. Therefore, the tester resources required is increased and also increases complexity and the total cost of testing and manufacturing the chip or module. SUMMARY Methods of testing a Multi-Chip Module which avoid the problems associated with the known testing techniques, reduce the required testing time and, therefore, the cost of manufacturing the module are described herein. Furthermore, a semiconductor package which includes at least two electronic circuits is also described herein, in particular a semiconductor package with at least two chips providing a multi-chip module. In this description, the phrase semiconductor package is used to denote a Multi-Chip Module or System-In-Package electronic component. A first of the at least two electronic circuits includes a digital input and a digital output and a test mode control line for setting the first semiconductor chip into a determined test mode. The digital input includes at least two parallel input paths and the digital output includes at least two parallel output paths. The at least two parallel input paths and at least two parallel output paths provide a corresponding number of internal paths by which the first electronic circuit and a second electronic circuit can be tested at essentially the same time. The above and still further features and advantages of the present invention will become apparent upon consideration of the following definitions, descriptions and descriptive figures of specific embodiments thereof, wherein like reference numerals in the various figures are utilized to designate like components. While these descriptions go into specific details of the invention, it should be understood that variations may and do exist and would be apparent to those skilled in the art based on the descriptions herein. BRIEF DESCRIPTION OF THE DRAWINGS The described device and methods are explained in more detail below with reference to the accompanying drawings, where: FIG. 1 shows a first multi-chip module with three semiconductor chips; FIG. 2 shows the multi-chip module of FIG. 1 in more detail; FIG. 3 illustrates two test patterns for sequentially testing two semiconductor chips of the multi-chip module of FIG. 1 or FIG. 2; FIG. 4 illustrates a test pattern for testing two semiconductor chips of the multi-chip module of FIG. 3 in parallel; and FIG. 5 shows a flowchart of the method by which the test patterns of FIG. 3 are merged to and from the test pattern of FIG. 4. DETAILED DESCRIPTION According to an exemplary embodiment, a semiconductor package includes at least two electronic circuits. A first of the at least two electronic circuits includes a digital input and a digital output and a test mode control line for setting the first semiconductor chip into a determined test mode. The digital input includes at least two parallel input paths and the digital output includes at least two parallel output paths. The at least two parallel input paths and at least two parallel output paths provide a corresponding number of internal paths by which the first electronic circuit and a second electronic circuit can be tested at essentially the same time. For example, if the first circuit includes three parallel digital input paths and three parallel digital output paths, three internal paths are provided in the package. As will be discussed in more detail below, this arrangement advantageously allows data to be processed in at least two internal paths essentially at the same time. The semiconductor package also includes at least one second circuit which is digitally coupled with the first circuit via an internal digital input/output path. Each second circuit also includes a test mode control line for setting the second circuit into a determined test mode, thus enabling the second circuit to be tested. When in the test mode, the first circuit is adapted to direct the data from one digital input path of the first circuit to the second circuit via the internal digital input/output path. This first circuit is also adapted to direct the data received at the internal path from the second circuit to one digital output path of the first circuit. The second circuit, while in the test mode, is adapted to process the data received at the internal path and to direct the processed data to the first circuit via the internal digital input/output path. This configuration enables the second circuit to be tested by a signal or data applied to the digital input path of the first circuit and output from the digital output path of the first circuit. This advantageously reduces the number of pins required in the package as digital input and output pins are not required specifically for the second circuit. The first circuit, while in the test mode, is also adapted to process the data received at a second digital input path and to direct the processed data to a second digital output path. Therefore, the first circuit is also tested by a signal or data applied to the digital input path of the first circuit. Therefore, in the described semiconductor package data is, advantageously, processed in the first circuit at the same time as data is processed in the second circuit. Therefore, both chips can be tested at essentially the same time and testing time is reduced. Optionally, the first circuit comprises a device to separate data at the digital input into data which is to be processed by the second circuit and into data which is to be processed by the first circuit. This enables data, which is for example an ATPG pattern, to be input into the package and the data appropriate for testing each chip to be separated and transferred to the appropriate chip. In a further embodiment, the second circuit may also include an analog module. Methods for electronically testing the described semiconductor package, in particular methods for testing the functionality of the electronic circuits of the package are also described herein. First, the digital input and digital output paths are connected to an electronic testing device. This is optionally performed by the external contacts of the package such as pins electrically connected to the input and output paths. If the package includes analog input and analog output paths, these are also connected to the electronic testing device. A test pattern such as an ATPG pattern is provided for each circuit in the semiconductor package. The test pattern includes a plurality of lines, each comprising a signal to be applied to the chip and its expected output. The test pattern can include ATPG patterns as well as functional patterns which cause the chips to test a desired operation or function such as “register access” in one chip and “Media Independent Interface” and the other chip using serial interface. The first circuit and the second circuit are then set into a predetermined test mode. A merged test pattern is produced by merging a respective line of each of the test patterns of the electronic circuits to form a single line in the merged test pattern. This advantageously enables each electronic circuit to be tested essentially at the same time as a single line of the merged test pattern is applied to the digital input of the first circuit. The data input is then separated by the first circuit and the appropriate data sent to and processed by the first and second circuits. When the first and second circuits are in test mode, the first circuit directs the data at a first input path to the second circuit via the internal digital input/output path and the first circuit directs the data received at the internal digital input/output path to a first output path. The first circuit processes the data at a second input path and directs the processed data to a second output path at essentially the same time. Due to the provision of a plurality of parallel digital input and output paths and the coupling of the first and second circuits, the functionality of the first circuit can be tested at essentially the same time as the functionality of the second circuit. The second circuit processes the data received at the internal digital input/output path and directs the processed data to the first circuit via the internal digital input/output path. This enables the second circuit to be tested by the data input at the digital input paths of the first circuit. The number of external digital input and outputs required to test the package is, therefore, reduced. Furthermore, since the test patterns for each chip are merged line-by-line into a single merged test pattern, the data required for testing both the first and second chip is included in the same line of the test pattern. The processing of the test data in the first circuit and in the second circuit is performed essentially in parallel. The output data of each digital output path is evaluated and compared with the expected data included in the test pattern. If the measured output deviates from the expected output, then the package is identified as containing a fault. Therefore, at least two circuits or semiconductor chips are advantageously tested in parallel at essentially the same time as a merged test pattern is used in which each line of the test pattern includes data for each semiconductor package. However, the individual test patterns for each chip may not be of the same length, i.e., contain the same number of lines. In this case, according to an exemplary embodiment, NOP instructions are written in one part of the test data, for example, in one part of a line of the merged ATPG pattern, when the other part still comprises valid test operation instructions. Therefore, the testing of one chip continues after the testing of a second chip is completed. This has the advantage that test patterns of any length can be merged and the testing time saving still be obtained. The testing method is, therefore, extremely flexible and can be used for parallel testing of different types of circuit and chips. Optionally, the method is carried out using a computer program product including a computer program. The computer program can be held on a storage medium, a computer memory or a direct access memory. The computer program for carrying out the method can be transmitted on an electric carrier signal. Optionally, the computer program can be downloaded from an electronic data network onto a computer which is connected to the data network (e.g., the Internet). In the following paragraphs, exemplary embodiments of the semiconductor package and methods are described in connection with the figures. FIG. 1 shows a schematic diagram of a multi-chip module 1 according to a first embodiment. The multi-chip module 1 includes three semiconductor chips A, B and C. For example, semiconductor chip A is an ADSL digital data pump, Chip B an ADSL analog Front end chip, and Chip C an Ethernet chip. Chip A includes a digital input path X and a digital output path Y which enable a digital signal to be respectively input and output to the package 1 by respective primary input X and output Y pins (which are not shown in the figure). Chip A also includes a test mode control line (which is also not shown in the figure) so that the chip can be set into a determined test mode. Chip A is also digitally coupled to semiconductor chip C by an internal input/output digital path P and to semiconductor chip B by an internal digital input/output path S. Semiconductor chips B and C also each include an analog signal input/output path Z and R respectively. Signal paths Z and R enable an analog signal to be applied to the module 1 via the package pins Z and R (not shown in the figure) which form external contacts of the module 1. Chips B and C further include analog circuits which are not shown in the diagram. The multi-chip module 1 also includes additional lines, also not shown in the diagram, for setting the chips B and C into a predetermined test mode. In multi-chip module 1, chip A can be tested using the Path X-Y, chip B by paths X-S-Z, Z-S-Y and X-S-Y and chip C by the paths X-P-R, R-P-Y and X-P-Y. To test each of the three semiconductor chips of the multi-chip module 1, at least three test modes are used, for example X-Y for chip A, X-S-Y for chip B and X-P-Y for chip C. FIG. 2 shows a more detailed schematic diagram of the multi-chip module 1. Parts of the module 1 which are essentially the same as those shown in FIG. 1 and denoted by the same reference are not necessarily described again. FIG. 2 shows that the multi-chip module 1 includes three parallel digital inputs X1, X2 and X3 and three parallel digital outputs Y1, Y2 and Y3 with respective primary package input and output pins. The semiconductor chips A, B and C in multi-chip module 1 are electrically configured to provide three test paths X2-Y2, X3-S-Y3 and X1-P-Y1 respectively. These test paths are shown diagrammatically by the arrows 4, 5 and 6 respectively. The semiconductor chip A, when set in the test mode, therefore directs data at one input path X1 to the semiconductor chip C via the internal path P and directs the data received at the internal path P to one output path Y1. The semiconductor chip A also processes the data at input path X2 directs the processed data to the output path Y2. Semiconductor chip C, when set in the test mode, processes the data received at the internal path P directs the processed data to semiconductor chip A via the internal path P. Similarly semiconductor chip A, when set in the test mode, directs data at one input path X3 to the semiconductor chip B via the internal path S and directs the data received at the internal path S to one output path Y3. Semiconductor chip B, when set in the test mode, processes the data received at the internal path S directs the processed data to semiconductor chip A via the internal path S. The semiconductor chip A, therefore, also has a device to separate data at the digital input X into data which is to be processed by semiconductor chips B and C and into data which is to be processed by semiconductor chip A. In order to test each chip in the multi-chip module, an Automatic Test Pattern Generation (ATPG) is generated for each chip in the module. FIG. 3 shows a schematic diagram of the ATPG pattern 2 for testing chip A and ATPG pattern 3 for chip B. Each pattern 2, 3 includes a test vector including a series of lines. The first half of the line, for example 1010101010 for Chip A, represents the signal input to chip A and the second half of the line, for example HLHLHLHL, represents the expected output if the chip A is functioning correctly. The actual output is measured by test nodes not shown in FIG. 1 and the measured output is compared with the expected output to determine if the chip is functioning as desired. If the measured output deviates from the expected output, the package is deemed to have an error. FIG. 3 shows a first test pattern or ATPG 2 for testing Chip A and a second test pattern or ATPG 3 for testing Chip B. Each line is run sequentially in time t from top to bottom of the diagram so that Chip A is tested in a time a and then Chip B is tested in time b. The total test time for the two chips A and B is, therefore, a+b. Since in the multi-chip module 1 of the exemplary embodiment, the input paths X1, X2, and X3 and output Y1, Y2 and Y3 paths are configured in parallel, the three test paths X1-P-Y1, X2-Y2 and X3-S-Y3 are able to be tested in parallel. According to the exemplary embodiment, in order to reduce the testing time of the multi-chip module 1, the ATPG test patterns for each of the paths X1-P-Y1, X2-Y2 and X3-S-Y3 are merged and run in parallel. Therefore, instead of the chips A, B and C being tested individually and sequentially as shown in FIG. 3, the chips A, B and C are tested in parallel. This is achieved by merging the ATPG patterns for the paths X1-P-Y1, X2-Y2 and X3-S-Y3. This is demonstrated in FIG. 4 for the parallel testing of chips A and B. The method may be extended to test any number of chips in parallel. FIG. 4 shows an ATPG pattern 7 in which the patterns 2, 3 of FIG. 3 for the chips A and B have been merged into a single pattern 7. As can be seen in the first 11 lines of the merged pattern 7, each respective line of the patterns 2 and 3 of FIG. 3 including the input signal and expected output signals for the Chips A and B are merged to from a single line. The chips 2, 3 are tested in parallel. For lines 12 onwards in the merged pattern 7, the testing of Chip A is complete so that an NOP instruction of 0000000 is applied to chip A. It can, therefore, be seen from FIG. 4 that via the multi-chip module 1 which includes the parallel digital input X1, X2 and X3 and output Y1, Y2 and Y3 paths and the use of the merged ATPG pattern 7, the testing time for the two chips is reduced to the time required to test chip B (i.e., the total testing time is reduced to b). FIG. 5 shows a flowchart of the method by which the ATPG patterns of each semiconductor chip in a multi-chip module are combined. Each ATPG pattern is generated at the same scan clock speed which is typically 10 MHz. To merge the ATPG test pattern, each test vector in the ATPG pattern is analyzed for repeat Opcode. If there are no repeats, the vectors are merged into a single test vector. If there are repeat test vectors for a chip, the vectors are expanded and merged. As illustrated by the previous diagrams, the provision of parallel digital input and output paths enables the parallel testing of the semiconductor chips in a multi-chip module via a test algorithm in which the ATPG test patterns of each chip are merged and the chips tested in parallel. This is extremely advantageous as the testing time for each module is reduced and, consequently, production costs are saved. The invention is also characterized by the following sets of elements: 1. A semiconductor package including at least two electronic circuits, a first circuit having a digital input and a digital output and a test mode control line for setting the first chip into a determined test mode, wherein the digital input includes at least two parallel input paths and the digital output includes at least two parallel output paths, the at least two parallel input paths and at least two parallel output paths providing a corresponding number of internal paths, and at least one second circuit being digitally coupled with the first circuit via an internal input/output path and having a test mode control line for setting the second circuit into a determined test mode, the first circuit, in the test mode, being adapted to direct the data at one input path to the second circuit via the internal path and the first circuit being adapted to direct the data received at the internal path to one output path, the first circuit, in the test mode, being adapted to process the data at one other input path and to direct the processed data to one other output path, the second circuit, in the test mode, being adapted to process the data received at the internal path and to direct processed data to the first circuit via the internal path. 2. A semiconductor package (1) according to item 1 wherein data is processed in the first circuit at the same time as data is processed in the second circuit. 3. A semiconductor package (1) according to item 1 or item 2 wherein the electronic circuits are semiconductor chips. 4. A semiconductor package (1) according to one of the previous items wherein the second circuit includes an analog module. 5. A semiconductor package (1) according one of the previous items wherein the first circuit has a device to separate data at the digital input into data which is to be processed by the second circuit and into data which is to be processed by the first circuit. 6. A method for electronically testing a semiconductor package (1) having the following steps: providing the semiconductor package of one of items 1 to 5, connecting the digital input, digital output and analog input and analog output paths to an electronic testing device, providing a test pattern (2, 3) for each electronic circuit including a signal to be applied to the chip and its expected output, producing a merged test pattern (7) by merging the respective lines of the test pattern (2, 3) of each electronic circuit to form a single line in the merged test pattern (7), setting the first circuit and the second circuit into a predetermined test mode, in which the first circuit directs the data at one input path to the second circuit via the internal path and the first circuit directs the data received at the internal path to one output path, and the first circuit, processes the data at one other input path and directs the processed data to one other output path, and the second circuit processes the data received at the internal path and directs the processed data to the first circuit via the internal path the data processing of the test data in the first circuit and in the second circuit being performed essentially in parallel, applying each line of the merged test pattern (7) to the parallel digital input paths of the electronic package, evaluating the output, comparing the measured output with the expected pattern, identifying packages in which the measured output deviates from the expected output. 7. A method for electronically testing a semiconductor package (1) according to item 6, wherein NOP instructions are written in one part of the test data when the other part still comprises valid test operation instructions. 8. A computer program product including a computer program for carrying out a method for electronically testing a semiconductor package (1) including at least two electronic circuits of one of items 1 to 5 which is in a form such that a method as claimed in one of items 6 or 7 can be carried out. 9. The computer program of item 8, which is held on a storage medium. 10. The computer program of item 8, which is stored in a computer memory. 11. The computer program of item 8, which is held in a direct access memory. 12. The computer program of item 8, which is transmitted on an electric carrier signal. 13. A data storage medium holding a computer program product including a computer program of item 8. 14. A method in which a computer program of item 8 is downloaded from an electronic data network onto a computer which is connected to the data network. 15. A method according to item 14, wherein the electronic data network is the Internet. While the invention has been described in detail with reference to specific embodiments thereof, it will be apparent to one of ordinary skill in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Accordingly, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
|
G
|
G01
|
G01R
|
31
|
08
|
|||
11777452
|
US20090014487A1-20090115
|
ADJUSTABLE HOLDING APPARATUS
|
ACCEPTED
|
20081230
|
20090115
|
[]
|
B60R706
|
["B60R706"]
|
7950637
|
20070713
|
20110531
|
269
|
045000
|
62312.0
|
NGUYEN
|
GEORGE
|
[{"inventor_name_last": "FAN", "inventor_name_first": "Eagle", "inventor_city": "Hsinchu", "inventor_state": "", "inventor_country": "TW"}]
|
An adjustable holding apparatus is provided, including a base unit, a clapping unit, and at least two stopping units. The base unit includes a surface on which the electronic device can be placed. The clapping unit is partially embedded in the base unit, and can move in the direction parallel to the surface of the base unit. The clapping unit includes a clapping part. The clapping part is located on one side of the clapping unit vertically. The stopping units are located at the lower part of the base unit with a distance separating the two stopping units. Each stopping unit includes a stopping part located at the upper part of stopping unit, and is off-center. The clapping part of the clapping unit and the stopping parts of the stopping units are located on the opposite sides of the surface of the base unit to form a three-point clapping on the device placed on the surface. The clapping units and the stopping units can be adjusted to accommodate a wide range of objects.
|
1. An adjustable holding apparatus, comprising: a base unit, having a flat surface for placing an object; a clapping unit, partially extending into said base unit for moving inwards and outwards of said base unit, having a clapping part on one side; and at least two stopping units, located at the lower part of said base unit, able to rotate for adjustment, each having a stopping part located on the upper part of said stopping unit, said stopping part being off-center of said stopping unit, said stopping units and said clapping unit being on opposite sides of said surface of said base unit, and when said stopping unit rotating, the position of said stopping part also changing. 2. The holding apparatus as claimed in claim 1, wherein the lower part of said base unit comprises at least two engaging trenches, said stopping unit further comprises an engaging part, said engaging part protruding from the lower part of said stopping unit and is engaged to said engaging trench when assembled. 3. The holding apparatus as claimed in claim 2, wherein the upper part of said engaging trench comprises a plurality of protruding blocks distributed as a ring, said trench forms a specific shape, said engaging part further comprises a plurality of blocks distributed as a ring on the upper part of said engaging part, when assembled, said blocks of said engaging part are engaged between two neighboring protruding blocks of said engaging trench. 4. The holding apparatus as claimed in claim 3, wherein the lower part of said engaging trench is wall forming a circular hole, the length of said engaging part is longer than the depth of engaging trench for short-distance upward and downward movement, the lower part of said engaging part comprises vertical trench, the outer circumference of the lower part matches the inner wall of said circular hole, and said the bottom of said engaging part comprises protruding hooking elements. 5. The holding apparatus as claimed in claim 2, wherein the shape of said engaging trench can be circular gear, pentagon, hexagon, or other shape with matching shape for said engaging part. 6. The holding apparatus as claimed in claim 1, wherein the inside of said base unit houses other mechanism for moving said clapping unit and fixing said clapping unit in place.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>A wide range of portable electronic devices are becoming a part of the modern daily life for most people, such as mobile phones, PDA, MP4, GPS, and so on. As most of the electronic devices are not standard options to the majority of the vehicles, the driver usually needs an additional holder to hold the electronic devices in place so that the use of these electronic devices will not interfere with the driving. However, as these electronic devices come in different sizes and shapes, a conventional holder may not be able to accommodate the different designs easily. For the user, the ideal holding apparatus should be small in size, and yet with a wide clapping range so as to hold electronic devices of various sizes as well as accommodate future electronic products. Conventional holders available in the market use a structure of two clapping arms on both sides to clap an electronic device. In this structure, one or two moveable clappers are installed in the holding seat. The clappers can move towards or away from each other for holding or releasing the electronic device. With this structure, the clapping range is restricted; for example, if the clapping position is not centered for the devices with long shape, the center of mass may be easily shifted, and the device slides off the clapping. Therefore, larger devices, such as audiovisual players, cannot be easily held. The holding apparatus of the present invention uses at least three clapping points to hold the device so that the center of mass of the device can be easily maintained in the accommodation area, and the holding apparatus can provide a firmer holding.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The primary object of the present invention is to provide an adjustable holding apparatus. The adjustable holding apparatus can provide holding space of various widths or shapes. At least three clapping points are used to hold the device as to provide a firmer holding on the device. Another object of the present invention is to provide an adjustable holding apparatus with a wide clapping range. By using a moveable clapping unit and at least two turnable stopping units to provide clapping for holding electronic devices of a variety of thickness and width. The stopping units include a stopping part. The stopping part is located off-center to the stopping unit, and when the stopping unit turns, the position of the stopping part changes. Therefore, the clapping points of the holding apparatus of the present invention provide a plurality of variations. Because the difference between the widest and the smallest clapping ranges is large, the holding apparatus can be applied to hold devices ranging from small mobile phones to large-screen GPS. To achieve the above objects, the present invention provides an adjustable holding apparatus, including a base unit, a clapping unit, and at least two stopping units. The base unit includes a surface on which the electronic device can be placed. The clapping unit is partially embedded in the base unit, and can move in the direction parallel to the surface of the base unit. The clapping unit includes a clapping part. The clapping part is located on one side of the clapping unit vertically. The stopping units are located at the lower part of the base unit with a distance separating the two stopping units. Each stopping unit includes a stopping part located at the upper part of stopping unit, and is off-center. The clapping part of the clapping unit and the stopping parts of the stopping units are located on the opposite sides of the surface of the base unit for clapping the device placed on the surface. The foregoing and other objects, features, aspects and advantages of the present invention will become better understood from a careful reading of a detailed description provided herein below with appropriate reference to the accompanying drawings.
|
FIELD OF THE INVENTION The present invention generally relates to a holding apparatus for electronic devices, and more specifically to an apparatus providing various clapping ranges of different width, length, and shape for application to hold various electronic devices. BACKGROUND OF THE INVENTION A wide range of portable electronic devices are becoming a part of the modern daily life for most people, such as mobile phones, PDA, MP4, GPS, and so on. As most of the electronic devices are not standard options to the majority of the vehicles, the driver usually needs an additional holder to hold the electronic devices in place so that the use of these electronic devices will not interfere with the driving. However, as these electronic devices come in different sizes and shapes, a conventional holder may not be able to accommodate the different designs easily. For the user, the ideal holding apparatus should be small in size, and yet with a wide clapping range so as to hold electronic devices of various sizes as well as accommodate future electronic products. Conventional holders available in the market use a structure of two clapping arms on both sides to clap an electronic device. In this structure, one or two moveable clappers are installed in the holding seat. The clappers can move towards or away from each other for holding or releasing the electronic device. With this structure, the clapping range is restricted; for example, if the clapping position is not centered for the devices with long shape, the center of mass may be easily shifted, and the device slides off the clapping. Therefore, larger devices, such as audiovisual players, cannot be easily held. The holding apparatus of the present invention uses at least three clapping points to hold the device so that the center of mass of the device can be easily maintained in the accommodation area, and the holding apparatus can provide a firmer holding. SUMMARY OF THE INVENTION The primary object of the present invention is to provide an adjustable holding apparatus. The adjustable holding apparatus can provide holding space of various widths or shapes. At least three clapping points are used to hold the device as to provide a firmer holding on the device. Another object of the present invention is to provide an adjustable holding apparatus with a wide clapping range. By using a moveable clapping unit and at least two turnable stopping units to provide clapping for holding electronic devices of a variety of thickness and width. The stopping units include a stopping part. The stopping part is located off-center to the stopping unit, and when the stopping unit turns, the position of the stopping part changes. Therefore, the clapping points of the holding apparatus of the present invention provide a plurality of variations. Because the difference between the widest and the smallest clapping ranges is large, the holding apparatus can be applied to hold devices ranging from small mobile phones to large-screen GPS. To achieve the above objects, the present invention provides an adjustable holding apparatus, including a base unit, a clapping unit, and at least two stopping units. The base unit includes a surface on which the electronic device can be placed. The clapping unit is partially embedded in the base unit, and can move in the direction parallel to the surface of the base unit. The clapping unit includes a clapping part. The clapping part is located on one side of the clapping unit vertically. The stopping units are located at the lower part of the base unit with a distance separating the two stopping units. Each stopping unit includes a stopping part located at the upper part of stopping unit, and is off-center. The clapping part of the clapping unit and the stopping parts of the stopping units are located on the opposite sides of the surface of the base unit for clapping the device placed on the surface. The foregoing and other objects, features, aspects and advantages of the present invention will become better understood from a careful reading of a detailed description provided herein below with appropriate reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The present invention can be understood in more detail by reading the subsequent detailed description in conjunction with the examples and references made to the accompanying drawings, wherein: FIG. 1 shows a 3D schematic view of the present invention; FIG. 2 shows a schematic view of the embodiment in FIG. 1 with the positions of the clapping unit and stopping units changed; FIG. 3 shows a partial exploded view of the present invention; FIG. 4 shows an enlarged schematic view of the stopping unit and engaging trench of the present invention; FIG. 5 shows an enlarged schematic view of the engaging trench on the back of base unit of the present invention; FIG. 6 shows a schematic view of the internal structure of the base unit of the present invention; and FIG. 7 shows a front view of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a 3D schematic view of the present invention. A holding apparatus A of the present invention includes a base unit 1, a clapping unit 2, and at least two stopping units 3. Base unit 1 has a large-area surface 11 on which an object can be placed. Base unit 1 includes sufficient internal space to house other structural mechanism and parts. Clapping unit 2 partially extends into the internal space of base unit 1. Clapping unit 2 also utilizes the mechanism housed inside the internal space of base unit 1 so that clapping unit 2 can move in the direction parallel to surface 11. The operational mechanism to moving clapping unit 2 is similar to the mechanism used in the conventional products, and the detailed description is omitted here. Clapping unit 2 includes a clapping part 21, and clapping part 21 is located vertically on one side of clapping unit 2. The height of clapping part 21 is higher than surface 11 so that clapping part 21 can clap the object placed on surface 11. Stopping units 3 are located on the two sides of the lower part of base unit 1. Each stopping unit 3 is separated from other stopping units 3 with a distance. Stopping unit 3 includes stopping part 31. Stopping part 31 is located vertically on the upper part of stopping unit 3, and is off-center to stopping unit 3. Stopping parts 31 and clapping part 21 are located on the opposite sides of surface 11 so as to form a three-point clapping on the object placed on surface 11. Stopping units 3 are not completely fastened to base unit 1. Stopping units 3 can adjust the position by rotation. As shown in FIG. 2, the rotation of stopping units 3 can change the position of stopping parts 31. Holding apparatus A of the present invention uses stopping parts 31 whose positions are adjustable, and moveable clapping part 21 to vary the clapping points so that the range, shape and size of the objects that can be clapped can vary. Also, by using at least three-point clapping, the holding to the object is stronger. In addition, a sponge sheath 311 can be used to cover stopping part 31 and a sponge pad can be placed on the inner wall of clapping part 21 to increase the friction of the clapping on the object. FIG. 3 shows a partial exploded view of the present invention. Although stopping unit 3 is located at the lower part of base unit 1, the rotation of stopping unit 3 can adjust the clapping position to accommodate different shapes and sizes of objects. There are many rotation mechanisms that can be used in the present invention, and the present embodiment only shows one possible rotation mechanism for description. In the present embodiment, the lower part of base unit 1 includes engaging trenches 13. As shown in FIG. 4, the upper part of engaging trench 13 has a specific shape, mainly including a plurality of protruding blocks 131 on the inner edge of the trench wall. In this embodiment, the shape of the trench is like a gear. The lower part of stopping unit 3 includes an engaging part 32 protruding vertically. The upper part of engaging part 32 includes a plurality of blocks 321 evenly distributed around the circumference. The embodiment shows four blocks 321. When assembled, each of four blocks 321 is stuck between two neighboring protruding blocks 131. Because there are 131 protruding blocks 131, the present embodiment provides 8 positions for the rotation of stopping unit 3. To adjust the position of stopping unit 3, stopping unit 3 is slightly pulled to disengage blocks 321 of engaging part 32 from protruding blocks 131 of engaging trench 13. Then, stopping unit 3 is turned to a new position, and pushed so that blocks 321 of engaging part 32 is engaged to and fastened to protruding blocks 131 of engaging trench 13. By using the above rotation mechanism, stopping units 3 can be adjusted and fixed to base unit 1. The shape of engaging trench 13 is not limited to the above embodiment, i.e., a gear, other shapes can also be used as long as the corresponding engaging part 32 has a matching shape. To make the adjustment of stopping unit 3 more convenient, the structures of engaging trench 13 and engaging part 32 can be designed. For example, the upper part of the trench wall of engaging trench 13 forms the shape of a gear trench, and the lower part of the trench wall forms a smooth circular hole 132 with a smaller diameter. As shown in FIG. 5, the depth of engaging trench is slightly shallower. As shown in FIG. 4, in addition to blocks 321, engaging part 32 can further include a plurality hooking elements 322. Blocks 321 are distributed along the circumference of the upper part of engaging part 32, and the lower part of engaging part 32 includes a cross trench 323. The outer circumference of the lower part of engaging part 32 matches circular hole 132, and the length is longer than the depth of engaging trench 13. Hooking element 322 is a small protruding element formed on the bottom of engaging part 32. When assembled, the lower part of engaging part 32 is slightly compressed so that hooking element 322 passing through circular hole 132 and engaged to bottom surface 133 of engaging trench 13, as shown in FIG. 5. With this engagement, engaging part 32 is fastened to engaging trench 13. As described, engaging part 32 is longer than the depth of engaging trench 13; therefore, engaging part 32 can be slightly pulled from the fastened engagement without entirely breaking away from engaging trench 13. When pulled to the top position, blocks 321 are disengaged from protruding blocks 131 so that engaging part 32 can rotate to adjust the position, and then be pushed down for engagement and fastening. FIG. 6 shows a schematic view of the internal structure of the base unit of the present invention. The mechanism inside base unit 1 is for the movement and the fixation of clapping unit 2. The mechanism includes a releasing unit 5, a fixing unit 6, and a spring 7. Clapping unit 2 cam move for a short distance within base unit 1, and includes a gear rack 22. Spring 7 provides the force for pushing clapping unit 2 outward. Fixing unit 6 includes a gear 61, and a snap element 62. Gear 61 is for fitting to gear rack 22 of clapping unit 2. Snap element 62 is for locking gear 61 in place so that gear 61 will not roll. Releasing unit 5 can move for a short distance laterally. When releasing unit 5 is pressed, snap element 62 is triggered to release the locking so that clapping unit 2 can move outward by the force of spring 7. FIG. 7 shows a front view of the present invention. Holding apparatus A of the present invention uses at least three clapping points to hold the object. The three-point clapping is provided by at least two stopping parts 31 of stopping units 3 and one clapping part 21 of clapping unit 2. Because the position of stopping part 31 is off-center to stopping unit 3, the position of stopping part 31 will change when stopping unit 3 rotates. The dash lines in FIG. 7 shows the possible positions for stopping parts. As shown in FIG. 7, the distance between two stopping parts 31 can vary, and when collaborating with moveable clapping part 21, the clapping range can vary even farther. Therefore, the three-point clapping of the present invention provides a clapping range that is adjustable to hold a wide variety of objects. Although the present invention has been described with reference to the preferred embodiments, it will be understood that the invention is not limited to the details described thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.
|
B
|
B60
|
B60R
|
7
|
06
|
|||
10581856
|
US20080044376A1-20080221
|
Cytokine Design
|
ACCEPTED
|
20080206
|
20080221
|
[]
|
A61K3819
|
["A61K3819", "A61P3500", "C07K1452"]
|
7994281
|
20070713
|
20110809
|
530
|
350000
|
99980.0
|
GAMETT
|
DANIEL
|
[{"inventor_name_last": "Tur", "inventor_name_first": "Vicente R.", "inventor_city": "Barcelona", "inventor_state": "", "inventor_country": "ES"}, {"inventor_name_last": "Van der Sloot", "inventor_name_first": "Albert Martinus", "inventor_city": "Barcelona", "inventor_state": "", "inventor_country": "ES"}, {"inventor_name_last": "Mullally", "inventor_name_first": "Margaret M.", "inventor_city": "Utrecht", "inventor_state": "", "inventor_country": "NL"}, {"inventor_name_last": "Cool", "inventor_name_first": "Robbert H.", "inventor_city": "Groningen", "inventor_state": "", "inventor_country": "NL"}, {"inventor_name_last": "Szegezdi", "inventor_name_first": "Eva E.", "inventor_city": "Galway", "inventor_state": "", "inventor_country": "IE"}, {"inventor_name_last": "Samali", "inventor_name_first": "Afshin", "inventor_city": "Galway", "inventor_state": "", "inventor_country": "IE"}, {"inventor_name_last": "Fernandez-Ballester", "inventor_name_first": "Gregorio", "inventor_city": "Heidelberg", "inventor_state": "", "inventor_country": "DE"}, {"inventor_name_last": "Serrano", "inventor_name_first": "Luis", "inventor_city": "Barcelona", "inventor_state": "", "inventor_country": "ES"}, {"inventor_name_last": "Ouax", "inventor_name_first": "Wilhelmus J.", "inventor_city": "Kropswolde", "inventor_state": "", "inventor_country": "NL"}]
|
The present invention relates to novel methods for the design of proteins, in particular, cytokines. These methods allow the stabilisation of such cytokines, as well as modification of their selectivity/specificity for their cognate receptors. The invention also relates to various modified proteins that have been designed by the methods of the invention.
|
1. A β sheet multimeric cytokine whose sequence has been altered by mutating a residue in a monomer component of the multimeric cytokine protein so as to improve the free energy of the monomer or of the multimeric complex relative to the wild-type unmutated monomer component so as to be more stable than the wild-type, unaltered cytokine protein, wherein said mutated residue is non-conserved between homologous members of the cytokine family. 2. A cytokine according to claim 1, which is a member of the TNF ligand family. 3. A cytokine according to claim 2, which is TRAIL. 4. A cytokine according to claim 3, which is mutated in the soluble C-terminal portion of the molecule. 5. A cytokine according to claim 1, which is mutated at one or more of the following positions: a) a non-conserved residue at the surface of the monomer component of the multimeric cytokine; b) a non-conserved residue close to the interface between two of the monomer components of the multimeric cytokine; c) for trimeric cytokines, a non-conserved residue along the central trimeric axis; d) a miscellaneous residue whose mutation is energetically favourable. 6. A cytokine according to claim 5, which is mutated in the external loop that connects that C and D anti-parallel beta strands (the CD loop), following the notation according to Eck (Eck et al., J. Biol. Chem. 267, 2119-2122 (1992). 7. A cytokine according to claim 5 part a), which is mutated at one or both positions 194 and 196. 8. A cytokine according to claim 7, which is a TRAIL mutant containing the mutations E194I and/or I196S. 9. A cytokine according to claim 5 part b), which is mutated at one or more of the positions 125, 163, 185, 187, 232, 234, 237, 203, 239, 241, 271, 274. 10. A cytokine according to claim 9, which is a TRAIL mutant containing one or more of the mutations D203I, Q205M and Y237F. 11. A cytokine according to claim 5 part c), which is mutated at one or more of positions 227, 230 and 240. 12. A cytokine according to claim 11, which is a TRAIL mutant containing the mutation R227M. 13. A cytokine according to claim 11, which is a TRAIL mutant containing the mutation C230S and Y240F. 14. A cytokine according to claim 5 part d), which is mutated at one or more of the positions 123, 272, 225, 280, 163, 123 and 208. 15. A cytokine according to claim 14, which is a TRAIL mutant containing the mutation S225A. 16. A cytokine which is mutated at more than one position as listed in claim 5, parts a) to d). 17. A cytokine according to claim 16, which is a TRAIL mutant containing the mutations E194I, I196S and S225A. 18. A cytokine according to claim 1, wherein the described mutations are introduced into a soluble form of the cytokine. 19. A cytokine according to claim 18, which is a TRAIL mutant comprising residues 114-281. 20. A β sheet multimeric cytokine with selectivity for a target receptor, in which one or more amino acids in the cytokine that are located in the receptor-binding interface are substituted for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity and selectivity/specificity of the cytokine protein for that target receptor, provided that these are not residues interacting with amino acids that are conserved among receptors bound by the cytokine protein. 21. A β sheet multimeric cytokine according to claim 20 which has altered affinity for a particular target receptor. 22. A β sheet multimeric cytokine with selectivity for two or more target receptors wherein selectivity for a first target receptor is achieved by substituting one or more amino acids in the cytokine for replacement residues so as to decrease affinity for one or more different target receptors, provided that these are not residues interacting with amino acids that are conserved among receptors bound by the cytokine protein. 23. A cytokine according to claim 20, which is mutated at one or more of the positions 131, 269, 130, 160, 218, 220, 149, 155, 214, 195, 191 and 267 in the cytokine. 24. A cytokine according to claim 20, which is a member of the TNF ligand family. 25. A cytokine according to claim 24, which is TRAIL. 26. A cytokine according to claim 25, which has superior selectivity for the DR5 (TRAIL-R2) or DR4 (TRAIL-R1) over the decoy receptors DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4). 27. A cytokine according to claim 25, which has superior selectivity for the death receptor 5 (TRAIL-R2) over selectivity for the death receptor 4 (TRAIL-R1). 28. A cytokine according to claim 26, which contains one or more of the mutations G131R, D269H, D269K, D269R, R130E, G160K, D218R, G160M, I220M, I220H, R149D, R149H, E155M, T214R, E195R, R191E and D267R. 29. A cytokine according to claim 28, which contains the mutations G160M or D269H. 30. A cytokine according to claim 28, which contains the mutations D269H and T214R. 31. A cytokine according to claim 28, which contains the mutations D269H and E195R. 32. A cytokine according to claim 28, which contains the mutations R191E and D267R. 33. A cytokine according to claim 25, which has superior selectivity for the death receptor 4 (TRAIL-R1) over selectivity for the death receptor 5 (TRAIL-R2). 34. A cytokine according to claim 33, which contains one or more of the mutations D218Y, D218E, D218K, D218H and D21E8F. 35. A β sheet multimeric cytokine with selectivity for a target receptor whose sequence has been altered by; a) mutating a residue in a monomer component of the multimeric cytokine protein so as to improve the free energy of the monomer of the multimeric complex relative to the wild-type unmutated monomer component, wherein said mutated residue is non-conserved between homologous members of the cytokine family, so as to be more stable than the wild-type, unaltered cytokine protein, and b) substituting one or more amino acids in the cytokine that are located in the receptor-binding interface for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity and selectivity/specificity of the cytokine protein for that target receptor, provided that these are not residues interacting with amino acids that are conserved among receptors bound by the cytokine protein, so as to provide variants with enhanced stability and increased binding affinity and selectivity/specificity for the target receptor. 36. A β sheet multimeric cytokine with selectivity for a target receptor whose sequence has been altered by; a) mutating a residue in a monomer component of the multimeric cytokine protein so as to improve the free energy of the monomer or of the multimeric complex relative to the wild-type unmutated monomer component, wherein said mutated residue is non-conserved between homologous members of the cytokine family, so as to be more stable than the wild-type, unaltered cytokine protein, and b) substituting one or more amino acids in the cytokine for replacement residues so as to decrease affinity for one or more different target receptors, provided that these are not residues interacting with amino acids that are conserved among receptors bound by the cytokine protein so as to provide variants with enhanced stability and selectivity/specificity for the target receptor. 37. A cytokine according to claim 35, which is a member of the TNF ligand family. 38. A cytokine according to claim 37, which is TRAIL. 39. A cytokine according to claim 38, which contains the mutations D269H and T214R. 40. A cytokine according to claim 38, which contains the mutations D269H, E194I and I196S. 41. A computer-implemented method for the stabilisation of a β sheet multimeric cytokine, comprising the step of: mutating a residue in a monomer component of the multimeric cytokine protein so as to improve the free energy of the monomer or of the multimeric complex relative to the wild-type unmutated monomer component; wherein said mutated residue is non-conserved between homologous members of the cytokine family. 42. A method according to claim 41, wherein the non-conserved residue that is mutated is at the surface of the monomer component of the multimeric cytokine protein. 43. A method according to claim 41, wherein the non-conserved residue that is mutated is near a position close to the interface between two monomer components of the cytokine protein. 44. A method according to claim 41, wherein in a trimeric cytokine protein, the non-conserved residue that is mutated is at a position along the central trimeric axis of the multimeric protein. 45. A method according to claim 41, wherein more than one non-conserved residue is mutated. 46. A method according to claim 41, wherein non-conserved residues are identified using a computer-implemented alignment algorithm. 47. A method according to claim 46, wherein in an alignment between the candidate for mutation and other members of the same protein family, a conserved residue is one that is shared between at least 50% of the family. 48. A method according to claim 41, wherein a protein design algorithm is used to facilitate the identification of candidate residues for mutation. 49. A method according to claim 48, wherein said method performs an energy calculation involving the following steps: a) identification of residues of a monomer that could establish specific interactions with the contiguous monomer; b) identification of side chains that contact residues that are candidates for mutation; c) at each residue position is placed each amino acid in a repertoire selected from a set of naturally occurring amino acids in a multiple sequence alignment of members of the same protein family, and any side-chain conformations and amino acids that are not compatible with the rest of the structure are eliminated; d) all possible pair-wise interactions are explored to eliminate those combinations that are not favourable. 50. A method according to claim 49, wherein said energy calculation is carried computationally, taking into account the properties of the structure, including its atomic contact map, the accessibility of its atoms and residues, the backbone dihedral angles, in addition to the H-bond network and electrostatic network of the protein, the contribution of water molecules making two or more H-bonds with the protein, polar and hydrophobic salvation energies, van de Waals' interactions, van de Waals' lashes, H-bond energies, electrostatics, and backbone and side chain entropies. 51. A method according to claim 50, wherein the method outputs a sequence and/or PDB coordinates corresponding to the best calculation solution. 52. A method according to claim 51, wherein the sequence and/or PDB co-ordinates including the mutations are energy-minimized and the final predicted energies are compared to the reference, wild-type structure in terms of Δ ΔG (kcal mol-1). 53. A method for the alteration of the selectivity of a β sheet multimeric cytokine for a target receptor, the method comprising a) identifying amino acids in the cytokine that are located in the receptor-binding interface as candidates for mutation; b) discarding residues interacting with amino acids that are conserved among receptors bound by the cytokine protein; c) discarding residues interacting with the receptor backbone; and d) substituting each of one or more residues in the cytokine protein for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity and selectivity/specificity of the cytokine protein for that target receptor. 54. A β sheet multimeric cytokine whose sequence has been altered by a method according to claim 53 so as to alter its affinity for a particular target receptor. 55. A cytokine according to claim 54, which is mutated at one or more of the positions 131, 269, 130, 160, 218, 220, 149, 155, 214, 195, 191 and 267. 56. A cytokine according to claim 52, which is a member of the TNF ligand family. 57. A cytokine according to claim 54, which is TRAIL. 58. A cytokine according to claim 57, which has superior selectivity for the DR5 (TRAIL-R2) or DR4 (TRAIL-R1) over the decoy receptors DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4). 59. A cytokine according to claim 57, which has superior selectivity for the death receptor 5 (TRAIL-R2) over selectivity for the death receptor 4 (TRAIL-R1). 60. A cytokine according to claim 58, which contains one or more of the mutations G131R, D269H, D269K, D269R, R130E, G160K, D218R, G160M, D218Y, D218E, D218K, D218H, I220M, I220H, R149D, R149H, D218F, E155M, T214R, E195R, R191E and D267R. 61. A cytokine according to claim 60, which contains the mutations G160M and D269H. 62. A method for obtaining variants of a β sheet multimeric cytokine with enhanced stability and increased binding affinity and selectivity/specificity for a target receptor comprising the steps of: a) mutating a residue in a monomer component of the multimeric cytokine protein so as to improve the free energy of the monomer or of the multimeric complex relative to the wild-type unmutated monomer component, wherein said mutated residue is non-conserved between homologous members of the cytokine family, and b) identifying amino acids in the cytokine that are located in the receptor-binding interface as candidates for mutation, discarding residues interacting with amino acids that are conserved among receptors bound by the cytokine protein, discarding residues interacting with the receptor backbone; and substituting each of one or more residues in the cytokine protein for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor. 63. A method of treating cancer by exposure of cancer cells to DR4-specific TRAIL variant in combination with cytotoxic therapies such as ionising radiation and chemotherapy. 64. A method of treating cancer by exposure of cancer cells to DR5-specific TRAIL variant in combination with cytotoxic therapies such as ionising radiation and chemotherapy. 65. Use of DR4-specific TRAIL variant in the manufacture of a medicament for the treatment of cancer, wherein the medicament is administered in combination with cytotoxic therapies such as ionising radiation and chemotherapy. 66. Use of DR5-specific TRAIL variant in the manufacture of a medicament for the treatment of cancer, wherein the medicament is administered in combination with cytotoxic therapies such as ionising radiation and chemotherapy. 67. A cytokine according to claim 22, which is mutated at one or more of the positions 131, 269, 130, 160, 218, 220, 149, 155, 214, 195, 191 and 267 in the cytokine. 68. A cytokine according to claim 22, which is a member of the TNF ligand family. 69. A cytokine according to claim 27, which contains one or more of the mutations G131R, D269H, D269K, D269R, R130E, G160K, D218R, G160M, I220M, I220H, R149D, R149H, E155M, T214R, E195R, R191E and D267R. 70. A cytokine according to claim 36, which is a member of the TNF ligand family. 71. A cytokine according to claim 53, which is a member of the TNF ligand family. 72. A cytokine according to claim 59, which contains one or more of the mutations G131R, D269H, D269K, D269R, R130E, G160K, D218R, G160M, D218Y, D218E, D218K, D218H, I220M, I220H, R149D, R149H, D218F, E155M, T214R, E195R, R191E and D267R.
|
<SOH> SUMMARY OF THE INVENTION <EOH>According to a first aspect of the invention, there is provided a computer-implemented method for the stabilisation of a β sheet multimeric cytokine, comprising the step of: mutating a residue in a monomer component of the multimeric cytokine protein so as to improve the free energy of the monomer or of the multimeric complex relative to the wild-type unmutated monomer component, wherein said mutated residue is non-conserved between homologous members of the cytokine family. Variants of β sheet multimeric cytokines with enhanced stability have a number of advantages, including increased in vivo and in vitro half-lives, increased yields generated during protein expression, greater stability during purification and an extended shelf-life compared to their wild-type counterparts. Stable variants of these proteins can thus be used as protein therapeutics or diagnostics. The proteins have a relatively close resemblance to the wild-type structure and this reduce the risk of immunogenicity, particularly when compared to variants stabilised by fusion tags, one currently favoured method of stabilising proteins. They also have advantages when compared to agonistic or antagonistic antibodies. In contrast to antibodies, variants can be produced in Escherichia coli and the mode of signalling more closely resembles that used by the wild-type cytokine protein. The term “multimeric cytokine” as used herein is meant to include all β sheet multimeric cytokines. Examples of such cytokines are presented in Table 6. Other examples will be known to those of skill in the art. A recent review on structure of TNF ligand family is available (Bodmer et al., 2002. Trends Biochem. Sci. 27, 19). One feature of β sheet multimeric cytokines is that they are composed of identical monomeric subunits or of different monomeric subunits. Methodologies could be applied to all cytokine protein families and more specifically to the members of the TNF ligand-receptor family. Other examples of families of proteins embraced by the superfamily of cytokines include those classed as Beta-Trefoil, Beta-sandwich, EGF-like, and Cystine knot cytokines). Of particular interest for the application of the methodology of the invention are the β sheet multimeric cytokines that are members of the tumor necrosis factor ligand family. Ligands belonging to this family are involved in a wide range of biological activities, ranging from cell proliferation to apoptosis, and they share similar structural characteristics. All monomeric subunits of these ligands consist of antiparallel β-sheets, organized in a jelly-roll topology, and these subunits self associate in bell-shaped homotrimers, the bioactive form of the ligand. A trimer binds three subunits of a cognate receptor, each receptor subunit binding in the grooves between two adjacent monomer subunits. The ligands are type II transmembrane proteins, but the extracellular domain of some members can be proteolytically cleaved from the cell surface, yielding a bioactive soluble form of the ligand. It has been found advantageous to use alignment information in order to focus the design on non-conserved residue positions. This method of protein stabilisation focuses on these non-conserved residues on the premise that conserved residues are usually retained in a family for a good reason and it is probable that any mutation of a conserved residue will decrease protein stability. On the other hand, regions with high sequence variability are tolerant to mutation and it can be expected that variants that stabilize the protein can be found in these regions. There is less evolutionary pressure for these residues to have been retained among the family members. The combined approach of the method therefore employs family alignment information and a computational design algorithm. This reduces the sequence space search for every position in the protein being studied and decreases the computing time and power necessary for the methodology. Identification of non-conserved residues can be done using any one of a number of systems known to the person of skill in the art. Such an analysis can be done by eye, but is more easily achieved using a computer-implemented alignment algorithm, such as BLAST (Altschul et al. (1990) J Mol Biol., 215(3): 403-10), FASTA (Pearson & Lipman, (1988) Proc Natl Acad Sci USA; 85(8): 2444-8) and, more preferably, PSI-BLAST (Altschul et al. (1997) Nucleic Acids Res., 25(17): 3389-402), ClustalW (Thompson et al., 1994, NAR, 22(22), 4673-4680) or the like. Assessment of whether or not a residue is conserved will be clear to the skilled reader and will depend on the number of related proteins that are aligned and the degree of relatedness amongst them. For example, if only two family members are aligned and these proteins share 50% identity, then the conserved residues are those that are shared between the two proteins at the same positions. On the other hand, if 20 proteins in the same family are aligned, it is most unlikely that the least alike of these proteins will possess homology as high as this. Preferably, then, in an alignment between the candidate for mutation and representative members of the protein family, a conserved residue is one that is shared between at least 20% of the family, preferably at least 30%, preferably at least 40%, preferably at least 50%, and may be at least 60%, preferably 70% or more. For example, sequence homology in the Tumor Necrosis Factor ligand family is highest between the (aromatic) residues that are responsible for trimer formation; these residues are thus unsuitable candidates for mutation according to the methodology of the invention. Once non-conserved residues are identified, the next step in the method requires an evaluation of which of these residues are candidates for mutation. Preferred aspects of the methodology mutate non-conserved residues that occupy positions at the surface of the monomer component in the multimeric cytokine protein structure. By doing this, the multimeric structure is stabilised as a whole. As used herein, the term “at the surface” means that the residue concerned in the monomer remains surface-exposed in the multimer complex. Such residues are solvent-exposed and thus hydrophilic in nature. Of course, surface-exposed residues will be present not only at the surface of each monomer, but will also be surface-exposed in the multimer complex. Knowledge of the position of a particular residue in the structure of a protein may come from knowledge of the structure itself, or may be derived by extrapolation from the position of the equivalent residue in the structure of a protein in the same family. Another preferred aspect of the methodology is to mutate non-conserved residues near positions close to the interface between two monomer components of the multimeric cytokine protein structure. This has the effect of stabilising the multimeric structure of the protein through stabilisation of the inter-chain interfaces. As used herein, the term “near positions close to the interface between two monomer components” means that the residue concerned in the monomer is close to or at the interface formed when two monomer components of a multimeric protein complex together. The residue must be near enough to this interface for its constituent atoms to influence monomer-monomer interactions, preferably in a positive way. For hydrophobic interactions the distance may be as close as the Van der Waals' radius of subject atoms. For hydrogen bonding the distance may be from 2.7 angstrom to 3.1 angstrom, for electrostatic interaction the distance may be from 1.4 angstrom up to 12 angstrom. Such influence may be effected through, for example, polar or hydrophobic solvation energies, van der Waals' interactions, H-bond energies, electrostatics, or backbone and side chain entropies. For trimeric proteins, one preferred aspect of the methodology is to mutate residues that occupy positions along the central trimeric axis in the multimeric cytokine protein structure. This has the effect of stabilising the trimer. As used herein, the term “residues along the central trimeric axis” means that the residue concerned in the monomer is close to or at the interface formed when three monomer components of a trimeric protein complex together. As described above, the residue must be near enough to this interface for its constituent atoms to influence the confluence of the three monomer components into a trimeric complex. Most preferably, a method according to the invention mutates residues in more than one of the classes referred to above, preferably in at least two of the classes and even more preferably in all three of these classes. The methodology described here is, to the inventors' knowledge, the first time that a technique incorporating computational engineering has been applied to redesign a large (>100 amino acids) all-β-sheet protein towards a more thermally stable variant. Until recently, lack of protein structural information in relation to multimeric β sheet cytokines and their receptors made intervention on the level of signal transduction initiation (ligand-receptor interaction) unfeasible. Detailed crystal structural information is now available for many of these cytokines, together with reliable homology models. Therefore, studies on protein-protein interaction and the elucidation of mechanisms of ligand-receptor interaction and activation are now possible. For example, the following TNF ligand family members have been crystallised, either in complexed or uncomplexed forms: Human BAFF, Blys (Liu Y. et al., 2002 Cell 108(3):383-94; Oren D A. et al., 2002 Nat Struct Biol., 9(4):288-92.; Karpusas M. et al., 2002 J Mol Biol. 315(5):1145-54); human CD40L (Karpusas M. et al., 2001 , Structure (Camb). April 4; 9(4):321-9); murine RANKL/TRANCE (Lam J. et al., 2001 J Clin Invest. 108(7):971-9); human TNF-a (Banner D W. et al., 1993 Cell. 1993 May 7; 73(3):431-45; Eck M J. et al., 1992 J Biol Chem., 267(4):2119-22.) human TRAIL (Mongkolsapaya J et al., 1999 Nat Struct Biol. 6(11):1048-53, Cha S S. et al., 1999, 2000 Immunity. 1999 August; 11(2):253-61. 2000 J Biol Chem. 2000 Oct. 6; 275(40):31171-7; Hymowitz S G. et al., 1999 Mol Cell. 4(4):563-71), human TNF-α (Reed C. et al., 1997 Protein Eng. 10(10):1101-7; Cha S S. et al., 1998 J Biol Chem. 1998 Jan. 23; 273(4):2153-60; Naismith J H. et al., 1996 Structure. 1996 Nov. 15; 4(11):1251-62, Naismith J H. et al., 1995, J Biol Chem. 1995 Jun. 2; 270(22):13303-7. 1996 J Mol Recognit. 1996 March-April; 9(2):113-7; Carter P C. et al., 2001 Proc Natl Acad Sci USA; 98(21):11879-84. Erratum in: Proc Natl Acad Sci USA 2001 Dec. 18; 98(26):15393). Therefore, the amino acids that make up domains representing protein-protein interaction motifs between these ligands and their respective receptors are now known. Such interacting domains in the TNF family have an intrinsic propensity to initiate signalling pathways associated with the modulation of diseases such as cancer and chronic diseases such as autoimmune disease, and are starting points for drug design. Visualisation of the structure of a candidate cytokine protein may be performed computationally using one or other of the many systems available for this task. Such systems are generally designed to import data describing a protein structure (such as a structure from the Protein Data Bank, the PDB) and convert this to a three-dimensional image. At present, the largest public depository of information relating to protein structure is the PDB database (http://www.rcsb.org/pdb), that now includes over 23,000 protein and nucleic acid structures, elucidated using methods of x-ray crystallography and nuclear magnetic resonance. Images of protein structure allow intimate analysis of the structure of a protein to evaluate the positions of each residue in the protein structure, and an evaluation of which residues participate in interactions with other moieties, such as a receptor or monomer partner. For example, in the example described herein, the structure of the TRAIL protein (Accession No. P50591; TN10_HUMAN, (SEQ ID NOs 1 and 2 herein)) is visualised using the template PDB structure 1DU3 (Cha et al., J. Biol. Chem. 275, 31171-31177 (2000)). The crystal structure at 2.2 Å resolution contains the trimeric structure of human TRAIL in complex with the ectodomain of the DR5 (TRAIL-R2) receptor. In this case, the TRAIL monomer lacks an external, flexible loop (130-146), not involved in receptor binding or in monomer-monomer interaction. Accordingly, to complete the molecule, this loop was modelled using the structure of 1D4V (2.2 Å) (Mongkolsapaya et al., Nat. Struct. Biol. 6, 1048-1053 (1999)), a monomeric TRAIL in complex with DR5 (TRAIL-R2) receptor, having the atomic coordinates of the loop. Finally, the TRAIL molecule was isolated by removing the receptor molecules from the PDB file. Already, there are computer-implemented programs that allow the prediction of protein structure ab initio, or by inference from closely-related proteins of known structure. Accordingly, for the method of the invention, it is not strictly necessary for the structure of a candidate protein to be known. A significant amount of information can be gleaned by analogy from structures of related proteins; for example, TNF ligand family members show similar trimeric structures. For example, for some β sheet multimeric cytokines, such as APRIL, there is no available structure of the complex with the receptor. However, there is generally structural information available for homologous ligands and receptors, which allows the complexes to be built by Homology Modelling. This is particularly true in those cases in which the sequence homology is higher then 40% and insertions or deletions are not found in the binding region of ligand and receptor. Visualisation of the isolated monomers, monomer-monomer interface and central core of the candidate protein will show the residues that are potential candidates for mutagenesis. In the case of design for stability mutants, in order to filter out unsuitable residues for mutagenesis, any highly conserved hydrophobic residues should be discarded from the list of potential candidates for mutagenesis. In addition, residues involved in receptor binding should be discarded in the case of design for stability mutants. These residues cannot be mutated without disrupting interactions with the receptor. The sequence space search for every position may preferably be simplified, by checking the naturally occurring amino acids in a multiple sequence alignment of proteins belonging to the family of interest, thus decreasing the computing time, and subsequently focusing on non-conserved residues. Preferably, in conjunction with a visualisation tool, a protein design algorithm is used to facilitate the identification of candidate residues for mutation. Examples of suitable algorithm include the “WHATIF” program (Vriend, (1990), J Mol Graph 8(1), 52-6, 29) or more sophisticated programs such as the algorithm “PERLA” (protein engineering rotamer library algorithm) (Fisinger S, Serrano L, Lacroix E. Protein Sci. 2001 April; 10(4):809-18). The latter, based on a rotamer library search, allows a combinatorial exploration at different positions simultaneously in the protein, and identifies the optimal sequence that improves a structural property of the protein (such as its stability). A detailed description of this algorithm is available elsewhere (Lacroix, E. Protein design: a computer based approach, Ph.D.thesis. (U. Libre de Bruxelles, 1999)) (http://ProteinDesign.EMBL-Heidelberg.DE) and its use has been previously described (Ventura et al., Nat. Struct. Biol. 9, 485-493 (2002); Fisinger et al., Protein Sci. 10, 809-818 (2001); Lopez et al., J. Mol. Biol. 312, 229-246 (2001); Reina et al., Nat. Struct. Biol. 9, 621-627 (2002)). Other suitable algorithms include 3D Jigsaw and EasyPred. Briefly, the PERLA algorithm performs strict inverse folding: a fixed backbone structure is decorated with amino acid side chains from a rotamer library. Relaxation of strain in the protein structure is achieved via the generation of subrotamers. Most terms of the scoring function are balanced with respect to a reference state, to simulate the denatured protein. The side chain conformers are all weighted using the mean-field theory and finally candidate sequences with modelled structures (PDB coordinates) are produced. In the case of a multimeric protein such as the TNF family ligand TRAIL, protein design with PERLA requires the following steps. Firstly, residues of a monomer that could establish specific interactions with the contiguous monomer must be identified and selected as described above. Secondly, side chains that contact the residues that are candidates for mutation must be identified to allow side chain movements that are necessary to accommodate the new residues introduced by the algorithm. PERLA automatically selects these residues based on a geometrical approach that takes Cα-Cα distances and the angle between Cα-Cβ vectors into consideration. Thirdly, the algorithm places the amino acid repertoire at each position selected from a set of naturally occurring amino acids in a multiple sequence alignment of the TNF ligand family, and eliminates from consideration those side-chain conformations and amino acids that are not compatible with the rest of the structure. Fourthly, all possible pair-wise interactions are explored to eliminate those combinations that are less favourable. This energy evaluation is preferably carried computationally, for example using a force field algorithm such as the program FOLD-X (Guerois et al., J. Mol. Biol. 320, 369-387 (2002)) or a modified version (Schymkowitz, J., Borg, J., Rousseau, F. & Serrano, L, “manuscript in preparation”) of this program, available at (http://fold-x.embl-heidelberg.de). The force field module of FOLD-X evaluates the properties of the structure, such as its atomic contact map, the accessibility of its atoms and residues and the backbone dihedral angles, in addition to the H-bond network and electrostatic network of the protein. The contribution of water molecules making two or more H-bonds with the protein is also preferably taken into account. FOLD-X then proceeds to calculate all force field components: polar and hydrophobic solvation energies, van der Waals' interactions, van der Waals' clashes, H-bond energies, electrostatics, and backbone and side chain entropies. Finally, an output of sequences and PDB coordinates corresponding to the best calculated solution (in terms of energy) is produced and may be ranked in terms of free energy, for instance, using FOLD-X. The resultant data files (preferably PDB files or similar) containing the mutations should then be energy-minimized. One way of doing this is by using a program such as GROMOS 43B1 as implemented in Swiss-PdbViewer v3.7b2 (Guex & Peitsch; Electrophoresis 18, 2714-2723 (1997)), and evaluated by FOLD-X (http://fold-x.embl-heidelberg.de). The final energies of the models are then compared to the reference, wild-type structure and expressed as ?? G (kcal mol −1 ). Favourable mutations may of course be combined and evaluated in terms of free energy (kcal mol-1). Unfavourable combinations (e.g. high Van der Waals' clashes) should be eliminated. If necessary, outputs of sequences and co-ordinates may subsequent to the design process be reintroduced in the design algorithm for a further round or rounds of design. 2nd, 3 rd , 4 th , 5 th or more rounds of design may be used. The above methodology facilitates the calculation of free energy, which must be improved by mutation of the monomer, relative to the free energy of wild-type unmutated monomer. By “free energy” is meant the free energy of folding. By “free energy of folding” is meant the difference in Gibbs energy (including enthalpic and entropic terms) between the protein in a folded or partially folded state and the protein in its fully denatured state. In calculating the free energy of folding, the calculation should take into account factors such as the accessibility of atoms, the existence of hydrogen bonds and the existence of electrostatic charges between atoms that are predicted to occur in the folded structure, the van der Waals' interactions, the solvation, the main chain and side chain entropic effects being also taken into account. These atomic energetic calculations are then summed. This calculation should thus ideally take account of the nature of the stabilising interactions that compete with or favour the topological constraints that are inherent in a particular protein folding pathway, taking sequence considerations into account when calculating the main chain, the side chain and the loop entropic costs and the favourable contributions to protein stability. Such a method thus should incorporate detailed energetic functions that effectively estimate the balance between topological constraints (entropic origin) on the one hand and interactions stabilising a fold, on the other. The free energy of a particular protein may be assessed using any suitable method, as will be clear to the skilled reader. A number of suitable computer programs exist for the automated calculation of free energy; one preferred program is the FOLD-X program (Guerois R, Nielsen J E, Serrano L., J Mol Biol. 2002 Jul. 5; 320(2):369-87) which uses optimal energy functions to rank sequences according to their fitness for a given fold. Such molecules identified herein specifically interfere at the ligand receptor family interface where apoptosis or autoimmune signalling pathways are triggered. A combined methodology that utilises the design approach outlined above in conjunction with such experimental techniques, is included as an aspect of the present invention. Molecules generated using the above methods may also be used to elucidate the mechanism of action of β sheet multimeric cytokines. For example, although the crystal structures of TNF family members are known, little is known of the exact mechanism of binding and signal initiation by the ligand-receptor complex. Several TNF ligand family members, such as TRAIL, APRIL and RANKL, bind more than one receptor type which depending on receptor type may or may not trigger signal transduction pathways. Many questions therefore still exist with respect to molecular regulation of diseases such as cancer or autoimmune disease on the level of ligand-receptor complex formation and subsequent initiation of signal transduction. In vitro and in vivo studies aimed at the characterisation of this complex should add to a better understanding of the underlying (patho) physiological response and will aid in creating unique lead molecules. Use of these lead compounds will facilitate the elucidation of more complex basic questions in relation to protein-protein interaction, signal transduction pathways and bioactivity in in vitro and in vivo situations. In particular, protein or peptide mimetics generated may act as receptor agonists, antagonists, which may be engineered to have increased or decreased structural stability, receptor binding selectivity and/or bioactivity. In particular, such compounds have utility in the regulation of apoptosis. Members of the TNF ligand family induce signalling pathways that lead to apoptosis or programmed cell death (PCD) through interaction with their cognate receptors. Ligand-bound receptors transmit the signal across the membrane by bringing their cytoplasmic portions into close proximity, leading to the recruitment and activation of downstream effector proteins. Apoptosis, the mechanism whereby multicellular organisms dispose of superfluous or damaged cells in a controlled manner, is a process fundamental to the normal development and homeostasis of multicellular organisms. However, the impairment of apoptosis regulation is implicated in the pathogenesis of cancer and several chronic diseases, including acquired immunodeficiency syndrome (autoimmune disease and AIDS) and neurodegenerative disorders (eg Parkinsons). Common examples are chronic transplant dysfunction, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD) and asthma. Molecules that mediate reversal of imbalance in signal transduction could be effective therapeutics in diseases. Cell induced apoptosis is mediated chiefly by members of the TNF ligand family that interact with cognate receptors to trigger apoptosis. Soluble portions of these cytokines or their receptors, or mimetics thereof, are thus attractive candidates to be used as therapeutics for a variety of diseases related to apoptosis impairment. In addition, a greater understanding of the role of TNF ligand family members may be achieved in controlling lymphocyte function, in order to identify novel targets for autoimmune therapy. Deregulated Activation-Induced Cell Death (AICD) may lead and contribute to autoimmunity. Impairment of AICD leads to accumulation of auto-reactive and chronically activated T cells. These cells can express various immune modulatory ligands, including APRIL and BAFF, which can alter B cell functions, causing autoantibody secretion and finally autoimmunity. The ligation of the TNF receptor family members may either lead to apoptosis through caspase-8/10 activation or, alternatively proinflammatory reactions, cell proliferation and differentiation through activation of NFkB. Activated T cells express a wide range of TNF ligand-receptor family members, all having different effects on lymphocyte fate. APRIL acts as a co-stimulator of T and B cells and enhances T cell survival in autoimmune disease. BAFF is essential for B cell T1 to T2 stage maturation, and thus, immunoglobulin secretion. RANKL initiates differentiation of osteoclast precursors that are responsible for bone desorption. In rheumatoid joints 40% of the leukocytes are T cells, mainly CD4+. The proportion of B cells is only 1-5%, although their contribution to chronic disease development is still great. Accumulation of these cells in inflamed joints leads to further lymphocyte activation and uncontrolled systemic immune responses. In RA, for example, one needs to target both hyper-plastic synovial cells and the immune cells accumulating in the joint capsule and also circulating in the body. TNF family members are important immune regulators through promotion of proliferation and by participating in AICD of peripheral T cells. Inhibition of endogenous TRAIL function leads to impaired AICD, proliferation of autoreactive lymphocytes and synovial cells resulting in arthritic inflammation and joint tissue destruction (Song K et al. J. Exp. Med., 2000; 191(7):1095). APRIL, on the other hand can act as a co-stimulator of T cells and is able to prolong T cell survival. By dissecting the molecular pathway of T cell activation and the cell death induced by reactivation we can understand the exact role of TNF ligand family members in autoimmunity. For example, studies of AICD human peripheral T cells may be isolated from the blood of healthy individuals. T cells can be activated by anti-CD3 and anti-CD28 antibodies, or phytohaemagglutinin and maintained in the presence of various amounts of IL-2 and/or IL-15. AICD will then be induced at various days following activation by addition of anti-CD3 monoclonal antibodies. The potential of various TNF family members to induce AICD of CD4+ or CD8+ T cell populations at various times can then be tested by addition of agonistic/antagonistic ligands such as those described herein; these will compete with signalling. Cell death in the CD4+ and CD8+ population can be tested by, for example, the 7-aminoactinomycin method (Szondy Z et al. 1998, J. Infectious. Dis. 178:1288). In addition, the requirement for IL-2 in sensitising activated T cells to TRAIL-R and Fas-mediated death will be examined. Since IL-15 was shown to inhibit AICD, we will examine whether IL-15 interferes with TNF receptor family expression of activated T cells and thus with sensitisation to AICD (Marks-Konczalik J. et al. PNAS 2000 97(21):11445-11450). Based on these findings a functional assay can be suggested to test possible deficiencies in various autoimmune patients. We will attempt to understand the function of APRIL in modulating T-cell survival. Using APRIL as a co-activator, together with anti-CD3, we will examine how it modulates TRAIL, FasL or TNF signalling, IL-2 secretion and in this way the influence on T cell survival. If TNF ligand family members or variants are shown to have an influence we will proceed to characterise these molecules in several forms of autoimmunity. According to a further aspect of the invention, therefore, there is provided a β sheet multimeric cytokine whose sequence has been altered so as to generate a more stable cytokine than the wild-type, unaltered cytokine protein. Preferably, the β sheet multimeric cytokine is generated by mutating a residue in a monomer component of the multimeric cytokine protein so as to improve the free energy of the monomer or of the multimeric complex relative to the wild-type unmutated monomer component, wherein said mutated residue is non-conserved between homologous members of the cytokine family. Multimeric cytokines included within the terms of the invention are all β sheet multimeric cytokines, as described above. Examples are presented in Table 6. Preferred multimeric cytokines according to the invention are members of the TNF ligand family (see Bodmer et al., 2002. Trends Biochem. Sci. 27, 19). A preferred TNF ligand family member is the TRAIL protein. Preferably, such a β sheet multimeric cytokine is mutated in the soluble C-terminal portion of the molecule. Examples of suitable residues for mutation are those at the following positions: a) a non-conserved residue at the surface of the monomer component of the multimeric cytokine (herein termed ‘monomer’ set); b) a non-conserved residue close to the interface between two of the monomer components of the multimeric cytokine (herein termed ‘dimer’ set); c) for trimeric cytokines, a non-conserved residue along the central trimeric axis (herein termed ‘trimer’ set). This list is not exhaustive—various miscellaneous mutations may also be made dependent on the particular cytokine, that do not fall into any of the three categories above. The identification of non-conserved residues is described above. Similarly, identification of residues that fall into the above classes a) to c) is also described above. Preferably, a mutation in category a) falls in the external loop that connects that C and D anti-parallel beta strands of the cytokine (the CD loop), following the notation according to Eck (Eck et al., J. Biol. Chem. 267, 2119-2122 (1992)). Preferred examples of such mutations in the TRAIL protein include positions E194 and I196. Equivalent mutations in other β sheet multimeric cytokines will be apparent to those of skill in the art. Preferably, mutations introduced at these residues are E194I and/or I196S. In the TRAIL protein, when both these mutations are made, this has been found to result in a large improvement of free energy compared to wild-type TRAIL (ΔΔG=−9.7 kcal mol −1 monomer −1 ). This high energy value is due to the fact that a trimer is being studied, in addition to the presence of significant van der Waals' clashes in the crystal structure (˜5 kcal mol −1 monomer −1 ), which are removed upon mutation. Preferably, mutations are made at both positions E194 and I196; more preferably, both the mutations E194I and I196S are made. The predicted increase in stability of this double mutant (herein termed M1) can be explained since Glu 194 is surrounded by hydrophobic groups (Trp 231, Phe 192, Ala 235) and the carboxyl group is uncompensated. The mutation Glu 194 to Ile rectifies this situation by replacing the charged residue for a medium-sized hydrophobic residue. Conversely, Ile 196 is surrounded by polar residues (Asn 202, Lys 233) and is very close to the backbone, resulting in probable van der Waals' clashes. Mutation to Ser avoids clashes and allows formation of a hydrogen bond to Asn 202, located in the opposite part of the CD loop. Both mutations improve polar solvation energy, in addition to ameliorating side chain and backbone entropy. Preferably, a mutation in the dimer set may be made at one or more of the following positions: 125, 163, 185, 187, 232, 234, 237, 203, 205, 239, 241, 271 and 274. In the TRAIL protein, the residues at these positions are the following: H125, F163, Y185, Q187, S232, D234, Y237, D203, Q205, L239, S241, E271 and F274. The skilled reader will be able to identify equivalent positions in other β sheet multimeric cytokine proteins, for example, by multiple alignment or by structural alignment. Preferred mutations in this class include mutations at D203, Q205 and Y237. Preferably, mutations introduced at these positions are one or more of D203I, Q205M and Y237F. More preferably, two or all three of these mutations are made. A mutant TRAIL protein comprising these three mutations is herein termed M2. The design of M2 leads to the creation of a hydrophobic cluster to stabilize the interaction between residues 203 and 205 (D strand) of one monomer, and residue 237 (F strand) of the adjacent monomer. Gln 205 and Tyr 237 together form an intermolecular hydrogen bond, and Asp 203 points to a gap in the monomer-monomer interface. Mutation to Ile (203), Met (205) and Phe (237) breaks the Q205-Y237 hydrogen bond, but facilitates the tight packing of these residues, improving van der Waals' interactions, hydrophobic and polar solvation energies of the entire TRAIL molecule, without a further increase of van der Waals' clashes. Preferably, a mutation in the trimer set may be made at one or more of the following positions: 227, 230 and 240. In the TRAIL protein, the residues at these positions are the following: R227, C230 and Y240. The skilled reader will be able to identify equivalent positions in other β sheet multimeric cytokine proteins. A preferred mutation in this class is R227M. A mutant TRAIL protein comprising this mutation is herein termed M4. The Arg 227 residues of mutant M4 are located in strand E, equidistantly opposed in a central position along the longitudinal axis of the TRAIL trimer. The three arginines are surrounded by hydrophobic (Ile 242), polar (Ser 241, Ser 225) and aromatic (Tyr 240, Tyr 243) residues. These tyrosines direct the hydroxyl groups away from Arg 227, thus creating a rather hydrophobic cavity. The high concentration of positive charges is apparently not well compensated, since it forms only hydrogen bonds with the backbone (carbonyl groups of Ser 241). Thus, the mutation of these positions to Met could help to accommodate the hydrophobic environment, as well as to decrease the repulsion of monomers due to uncompensated positive charges. Also the combination of C230S and Y240 is preferred. Replacement of the Cys 230 with Ser removes a zinc binding site thereby introducing unfavourable interactions. The second mutation (Y240F) removes unfavourable interactions to restore thermal stability and biological activity. Preferably, a mutation in the miscellaneous set may be made at one or more of the following positions: 123, 272, 225, 280, 163, 123 and 208. In the TRAIL protein, the residues at these positions are the following: A123, A272, S225, V280, F163, A123 and V208. The skilled reader will be able to identify equivalent positions in other β sheet multimeric cytokine proteins. A preferred mutation in this class is S225A. A mutant TRAIL protein comprising this mutation is herein termed M3. Residue 225 of M3 (S225A) is located in strand E and is solvent exposed in the monomeric form. However, after trimerization, this position becomes buried in a small pocket, leaving the side chain of the hydrogen bond donor Ser uncompensated. After mutation to Ala, the energy of the model is better than wild-type TRAIL for both polar and hydrophobic solvation energies, in addition to side chain entropy. A further preferred mutant β sheet multimeric cytokine is one which incorporates a combination of the mutations described above, such as 2, 3, 4, 5, 6, 7, 8, 9, 10 or more such mutations. One example of such a mutant combines mutations at positions 194, 196 and 225. In the TRAIL protein, the residues at these positions are E194, I196 and S225. Preferably, the mutations introduced are E194I, I196S and S225A; a TRAIL mutant containing these three mutations has been engineered and is referred to herein as C1. The above mutations may be introduced in the full length cytokine sequence. Preferably, however, the above mutations are introduced into soluble forms of β sheet multimeric cytokines. For the TRAIL protein, a preferred soluble template into which these mutations may be introduced comprises amino acids 114-281 of the full length TRAIL protein. However, as the skilled reader will appreciate, variations in this template will very likely retain the properties of this soluble form and show biological activity if additional residues C terminal and/or N terminal of these boundaries in the polypeptide sequence are included. For example, an additional 1, 2, 3, 4, 5, 10, 20 or even 30 or more amino acid residues from the wild-type cytokine sequence, or from a homologous sequence, may be included at either or both the C terminal and/or N terminal of these boundaries, without prejudicing the ability of the polypeptide fragment to fold correctly and exhibit biological activity. Similarly, truncated variants of this template in which one or a few amino acid residues (for example, 1, 2, 3, 4, 5, 10 or more) may be deleted at either or both the C terminus or the N terminus without prejudicing biological activity The methods described above have been applied to a prototypic example, TRAIL, for purposes of illustration. It will be appreciated that this example is intended as illustrative and is not limiting in any way. Novel mutants of TRAIL have been designed in order to increase the stability of the bioactive trimer. As will be evident from the Examples included herein, using this approach succeeded in extending the apparent thermal stability of the β-sheet protein by more than 5° C. This correlates with the preservation of overall structural characteristics as highlighted by the lasting bioactivity of these mutants as tested experimentally. For example, when measuring the residual bioactivity of wild-type TRAIL and TRAIL mutants upon incubation at 73° C. for 1 hour, it was shown that, while wild-type TRAIL was all but thermally inactivated after ˜20 min, the TRAIL mutants M1, M2, M3 and C1, significantly, had an improved stability. Although not tested herein, it has been shown that in case of certain therapeutically interesting proteins, improvement of thermal stability can also be indicative of an improved in vivo half-life (Luo et al., Protein Sci. 11, 1218-1226 (2002); Filikov et al., Protein Sci. 11, 1452-1461 (2002)). Furthermore, the increase in thermal stability did not affect the biological activity of M1, M3 and C1. Significantly, it is shown herein that stabilisation of the CD loop in a single monomer resulted in stabilisation of the entire trimeric molecule. As stated above, it would be desirable were it to be possible to alter the selectivity/specificity of cytokines for their cognate receptors. The inventors have now achieved, for the first time, the alteration of the receptor binding selectivity/specificity of a large multimeric protein structure using computational redesign. Automated computer algorithms have been used in combination with hand-crafting and selection of pertinent residues to alter receptor binding selectivity of a multimeric all β-sheet protein, TRAIL. Accordingly, this aspect of the invention provides a method for the alteration of the selectivity of a β sheet multimeric cytokine for a target receptor, the method comprising identifying amino acids in the cytokine that are located in the receptor-binding interface as candidates for mutation; discarding residues interacting with amino acids that are conserved among receptors bound by the cytokine protein; discarding residues interacting with the receptor backbone; and substituting each of one or more residues in the cytokine protein for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity of the cytokine protein for that target receptor. Alternatively, one or more residues in the cytokine protein may be substituted for replacement residues so as to decrease the binding affinity of the cytokine protein for a particular target receptor. The invention also provides a β sheet multimeric cytokine that is obtained or obtainable by the above methodology. The invention also provides a β sheet multimeric cytokine with selectivity for a target receptor, wherein one or more amino acids in the cytokine that are located in the receptor-binding interface are substituted for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity and selectivity/specificity of the cytokine protein for that target receptor, provided that these are not residues interacting with amino acids that are conserved among receptors bound by the cytokine protein. Alternatively, the invention provides a β sheet multimeric cytokine with selectivity for two or more target receptors wherein selectivity for a first target receptor is achieved by substituting one or more amino acids in the cytokine for replacement residues so as to decrease affinity for one or more different target receptors, provided that these are not residues interacting with amino acids that are conserved among receptors bound by the cytokine protein. The target receptors referred to herein may be cognate receptors. As discussed above, alteration of selectivity for receptor is of significant interest in the cytokine field. For example, TNF ligand family members bind to receptors of the TNF receptor family, and upon binding an intracellular signalling cascade is activated. Different cell subtypes have different profiles of TNF receptor family expression. Many TNF ligand family members can signal through more than one type of TNF receptor family member proteins, resulting in different biological activities, depending on the receptor and the expression profiles of these receptors on the cell surface. For a protein therapeutic/diagnostic it may be advantageous to selectively activate (or inhibit) one of the receptors, for example to differentiate between a cell-proliferating activity and a cell-death inducing activity. Using the method of the invention described above, this is now possible even for large multimeric molecules. Furthermore, an improved selectivity/specificity would allow lower concentrations of a therapeutic variant to be administered than would be necessary with respect to wild-type cytokine. Such selective variants of cytokines are advantageous for use as protein therapeutics or diagnostics, since they exhibit a relatively close resemblance to the wild-type structure and this reduces the risk of immunogenicity. They also have advantages when compared to agonistic or antagonistic antibodies. In contrast to antibodies, variants can be produced in Escherichia coli and the mode of signalling resembles the wild-type mode of signalling more closely. According to the method of this aspect of the invention, selectivity for receptor is of primary importance. Accordingly, affinity for a receptor may be slightly compromised for improvements in selectivity/specificity. Using a method such as that described herein, novel mutants of the TRAIL protein have been designed in order to shift selectivity/specificity towards its different membrane receptors (DR4 (TRAIL-R1), DR5 (TRAIL-R2), DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4)). As described above, having selective inducers of DR4 (TRAIL-R1) and DR5 (TRAIL-R2) signalling is of considerable interest, due to the different cross-linking requirements of both death receptors. Depending on the cross-linking the signalling pathway could induce the proliferative or the apoptic pathway. Some residues important for binding and biological activity have been already identified in TRAIL by alanine-scanning mutagenesis (Hymowitz et al., Biochemistry. 2000 Feb. 1; 39(4):633-40), but in this study, the inventors have focused not only in the identification of critical residues for selectivity, also have suggested the best amino acid substitution at these positions to get a maximum effect in selectivity. We show that some residues are critical for receptor binding and selectivity; alanine-scanning mutagenesis could not identify these. The results also confirm that the choice of amino acid chosen for replacement is important. This example acts as a prototypic example of how the method of the invention may be applied to a large multimeric β sheet protein. As the skilled reader will be aware, methods used in this study are also applicable to other multimeric cytokines, such as TNF family ligands. For example, a recent significant publication has shown that TRAIL-R3 is upregulated by p53 in breast tumour cell through use of the genotoxic drug, doxorubicin (Ruiz de Almodóvar et al., J. Biol. Chem 6; 279(6):4093-101 (2003). This implies that efficacy of wild-type TRAIL may be diminished in anti-tumour therapy since it also binds the decoy receptors (that do not initiate apoptosis). Therefore, variants of TRAIL, that have altered selectivity/specificity could be directed to the pro-apoptotic receptors, DR4 (TRAIL-R1) or DR5 (TRAIL-R2) and would have ultimately improved application in cancer treatment. Methods for identifying amino acids that are located in the receptor-binding interface are known in the art. Preferably, this is done through visualisation of the structure of the ligand protein, ideally in complexed form with receptor, using one or other of the many systems available. Such systems are generally designed to import data describing a protein structure (such as a structure from the Protein Data Bank, the PDB) and convert this to a three-dimensional image. Images of protein structure allow intimate analysis of the structure of the protein to evaluate the positions of each residue in the protein structure, and an evaluation of which residues participate in interactions with other moieties, such as a receptor or monomer partner. Selected side chains are those in the protein ligand that are physically close enough to be potentially interacting with receptor. If no protein structure is available, it is likely that there will be structural information available for one or more homologous ligands and receptors, which allows the complexes to be built by Homology Modelling. This is particularly true in those cases in which the sequence homology is higher then 40% and insertions or deletions are not found in the binding region of ligand and receptor. For example, in the specific case of alteration of the selectivity of the TRAIL protein for DR5 (TRAIL-R2) or towards DR4 (TRAIL-R1), a crystal model of TRAIL in complex with the ectodomain of the DR5 (TRAIL-R2) receptor is available (PDB identifier 1DU3). Models of TRAIL complexed with the three other membrane receptors (DR4 (TRAIL-R1), DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4)) may be obtained using the “What If Homology Modeling web interface” (Vriend. WHAT IF: A molecular modeling and drug design program. J Mol. Graph. (1990) 8, 52-56) (available at http://www.cmbi.kun.nl/gv/servers/WIWWWI/). Pdb files of TRAIL in complex with these three receptors can be generated by imposing their backbone atoms over the same atoms of the receptor DR5 (TRAIL-R2), using a program such as Swiss-PdbViewer v3.7b2 (Guex & Peitsch. SWISS-MODEL and the Swiss-PdbViewer: an environment for comparative protein modeling. Electrophoresis 18, 2714-2723 (1997)). Finally, template receptor DR5 (TRAIL-R2) is removed from the generated PDB file. In a similar manner to the method of protein stabilisation described above, it is considered advantageous to use alignment information in order to focus the design on residues that do not interact with conserved residue positions in the target receptor. On occasion, however, altering conserved residues may also lead to changes in selectivity for the receptor. By conserved residue positions, is meant residues that are conserved between the different receptors that bind to the protein of interest. For example, the TNF ligand family TRAIL binds to four different membrane receptors (DR4 (TRAIL-R1), DR5 (TRAIL-R2), DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4)). Residues in the receptor binding interface that are conserved between the different receptors are likely to contribute to the binding of the ligand protein, meaning that their alteration would very likely disrupt important ligand-receptor interactions that are necessary for effective ligand-receptor binding. For the same reason, any residues that are predicted to interact with the receptor backbone are not considered suitable candidates for mutation. As described above, identification of non-conserved residues can be done using any one of a number of systems known to the person of skill in the art, but preferably, computer-implemented alignment algorithms such as PSI-BLAST or ClustalW are preferred. The combined approach of the method therefore employs family alignment information and a computational design algorithm. This reduces the sequence space search for every position in the protein being studied and decreases the computing time and power necessary for the methodology. This methodology allows rational design of the occurring interactions between the protein ligand and its receptors. An overall visual inspection of the binding interface of ligand with the different receptors should also be carried out and, if necessary, some rotamers changed. The method requires that each of one or more residues in the ligand protein are substituted for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity for that receptor. This step is preferably performed using a computer design algorithm such as PERLA, which performs inverse folding. Briefly, this algorithm decorates a fixed backbone structure with amino acid side chains from a rotamer library. PERLA thus performs a rotamer search looking for better side chain conformations, aiming to model the expected interactions of the protein ligand with its receptors. Relaxation of strain in the protein structure is achieved via the generation of subrotamers. Most terms of the scoring function are balanced with respect to a reference state, to simulate the denatured protein. The side chain conformers are all weighted using the mean-field theory and finally candidate sequences with modelled structures (PDB coordinates) are produced. Energy evaluation of the modelled structure must also be performed as part of this methodology, preferably using a program such as FOLD-X 7 or an improved version (such as that available at http://fold-x.embl-heidelberg.de). The force field module of FOLD-X evaluates the properties of the structure, such as its atomic contact map, the accessibility of its atoms and residues, the backbone dihedral angles, in addition to the H-bond network and electrostatic network of the protein. The contribution of water molecules making two or more H-bonds with the protein is also taken into account. FOLD-X then proceeds to calculate all force field components: polar and hydrophobic solvation energies, van der Waals' interactions, van der Waals' clashes, H-bond energies, electrostatics, and backbone and side chain entropies. Using this program, all possible amino acid substitutions (preferably with the exception of Glycine, Proline, and Cysteine) are then introduced at the selected residue positions in the protein ligand in conformations (side chain rotamers) that are compatible with the rest of the structure. Glycine, Proline, and Cysteine are preferably omitted because Gly and Pro can influence the backbone conformation relatively more than other amino acids (Gly is more flexible, Pro less so). Also these residues have relatively large effects in the denatured state (Gly high entropy, Pro lower). Cys can also be difficult and is in an unpaired state that is generally unwanted in proteins, making them prone to aggregation and the like. Favourable mutations are then evaluated in terms of free energy (kcal mol-1), and unfavourable mutations (e.g. high Van der Waals' clashes) eliminated. An output of sequences and coordinates is then obtained and ranked in terms of free energy, for example, using the FOLD-X program. Some of these predictions can be discarded directly after theoretical energy calculations, without further experimental analysis. Others are progressed to mutagenesis studies. In this way, the method of this aspect of the invention substitutes one or more residues in the ligand protein substituted for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity for that target receptor. Favourable mutations may of course be combined and evaluated in terms of free energy (kcal mol-1). Unfavourable combinations (e.g. high Van der Waals' clashes) should be eliminated. If necessary, outputs of sequences and co-ordinates may subsequent to the design process be reintroduced in the design algorithm for a further round or rounds of design. 2nd, 3 rd , 4 th , 5 th or more rounds of design may be used. Preferably, the method of this aspect of the invention may be applied to multimeric β sheet cytokines. Examples of such cytokines are presented in Table 6. Other examples will be known to those of skill in the art. Of particular interest for the application of the methodology of the invention are the β sheet multimeric cytokines that are members of the tumor necrosis factor ligand family. Ligands belonging to this family are involved in a wide range of biological activities, ranging from cell proliferation to apoptosis, and they share similar structural characteristics. According to a further aspect of the invention, there is provided a β sheet multimeric cytokine whose sequence has been altered so as to alter its affinity for a particular target receptor. Accordingly, one aspect of the invention relates to a cytokine that is mutated at one, two, three, four, five, six, seven, eight, nine, ten, eleven or all twelve of these positions. Preferably, such a cytokine is a member of the TNF ligand family. More preferably, such a cytokine is TRAIL (SEQ ID NO:1 herein). All references to amino acid positions in the TRAIL protein sequence presented herein, and to specific TRIAL mutants are intended to refer to the amino acid sequence given in SEQ ID NO:1. Preferably, the TRAIL sequence is altered so as to alter affinity and/or selectivity for the DR4 (TRAIL-R1) or DR5 (TRAIL R2) receptors. Examples of suitable residues for mutation in TRAIL are those at the following positions: 131, 269, 130, 160, 218, 220, 149, 155, 214, 195, 191 and 267. Equivalent residues (when crystal structural information is compared by eye or with use of molecular modelling) identified by those skilled in the art could be mutated in other β sheet multimeric cytokines, preference being for the cytokines of the TNF family. Equivalent substitutions at the above positions, with a specific type of residue are preferred. For example, a preferred mutation at position 131 is to Arg. Preferred mutations at position 269 are to His, Lys or Arg. A preferred mutation at position 130 is to Glu. Preferred mutations at position 160 are Lys and Met. Preferred mutations at position 218 are to Arg, Tyr, Glu, Phe, Lys or His. Preferred mutations at position 220 are to Met or to His. Preferred mutations at position 149 are to Asp or to His. A preferred mutation at position 155 is to Met. A preferred mutation at position 214 is to Arg. A preferred mutation at position 195 is to Arg. A preferred mutation at position 191 is to Glu. A preferred mutation at position 267 is to Arg. In the TRAIL protein, preferred mutations are G131R, D269H, D269K, D269R, R130E, G160K, D218R, G160M, D218Y, D218E, D218K, D218H, I220M, I220H, R149D, R149H, D218F, E155M, T214R, E195R, R191E and D267R. Particularly preferred TRAIL mutants are G160M, D269H, D218Y, R130E and I220M. In particular, the G160M, D269H, D269K, D269R, T214R and E195R mutants are preferred as these are shown herein to have superior selectivity for the death receptor 5. Some critical residues identified in TRAIL for receptor binding without distinction between DR4 and DR5 (TRAIL-R2) have been identified as Ile 220, Arg 149, Glu 155, Gly 160 and Asp 218. The I220H and I220M mutants both highly increase DR4 binding, and have no effect on DR5 binding. The R149D mutant decreases binding to both the DR4 and DR5 receptors, whilst the R149H and D218R mutants have no effect on binding to either of these receptors. The E155 mutant highly decreases binding to both the DR4 and DR5 receptors; the D218F and D218Y mutants also decrease affinity, although to a lesser extent. Furthermore, the D218Y mutant demonstrates a larger decrease in DR5-affinity than DR4-affinity. Whereas wild type TRAIL has a higher affinity for DR5 than DR4, this preference is lost in the mutant and the overall effect of the D218Y mutation is to shift selectivity towards DR4 (TRAILR1). In the same way, the D218K, D218R, D218E and D218H mutants have superior selectivity for DR4 (TRAIL-R1). Also, it has been shown that different amino acid substitutions in the same position can have a different effect on receptor binding. Some positions, critical for receptor selectivity, due to a different decrease in receptor binding affinity between DR4 (TRAIL-R1) and DR5 (TRAIL-R2) have been identified as Arg 130, Gly 131 and Asp 269. The R130E and G131R mutants decrease binding to DR4 but only slightly decrease binding to DR5. In contrast, the D269H mutant highly decreases binding to DR4. Initial experiments shows that the D269H mutant had no observable effect on binding to DR5, although more recent experiments confirm that in fact this mutant significantly increases binding to DR5. The same receptor binding preferences are demonstrated by variants D269K and D269R. The skilled reader will be able to identify equivalent positions in other β sheet multimeric cytokine proteins, for example, using multiple alignment programs or manual inspection of related sequences or structures. Preferably, affinity for receptor is improved for DR4 (TRAIL-R1) or DR5 (TRAIL-R2) over the affinity for the decoy receptors DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4). More preferably still, affinity for DR5 (TRAIL-R2) receptor is improved over affinity for DR4 (TRAIL-R1). Alternatively, affinity for DR4 (TRAIL-R1) receptor is improved over affinity for DR5 (TRAIL-R2). The above mutations may be introduced in the full length cytokine sequence. Preferably, however, the above mutations are introduced into soluble forms of β sheet multimeric cytokines. For the TRAIL protein, a preferred soluble template into which these mutations may be introduced comprises amino acids 114-281. Equivalent soluble forms of other cytokines will be clear to the skilled reader. However, as the skilled reader will appreciate, variations in this template will very likely retain the properties of this soluble form and show biological activity if additional residues C terminal and/or N terminal of these boundaries in the polypeptide sequence are included. For example, an additional 1, 2, 3, 4, 5, 10, 20 or even 30 or more amino acid residues from the wild-type cytokine sequence, or from a homologous sequence, may be included at either or both the C terminal and/or N terminal of these boundaries, without prejudicing the ability of the polypeptide fragment to fold correctly and exhibit biological activity. Similarly, truncated variants of this template in which one or a few amino acid residues (for example, 1, 2, 3, 4, 5, 10 or more) may be deleted at either or both the C terminus or the N terminus without prejudicing biological activity. The skilled reader will appreciate that the methods described herein for the alteration of selectivity of a multimeric β sheet cytokine molecule may be combined. In particular, combinations of the selectivity/specificity mutations to give variants with enhanced selectivity. For example, variants with altered selectivity/specificity can be combined with variants with an increased selectivity/specificity. Preferably, the positions of the combined mutations are far enough away from each other so that they cannot make any predictable interaction with each other. As such, both mutations may contribute to selectivity in an independent way. Such combinations of receptor selective/specific mutations and the variants they encode are included as specific aspects of the present invention. Examples of such molecules include combinations of one or more of the D269H, E195R, T214R, D267R, D269K, D269R and R191E selectivity/specificity mutants, which give variants with enhanced selectivity/specificity. A particularly preferred example is the combination of the R191E mutation with the D267R mutation to give the R191ED267R variant. The methods described above have been applied to a prototypic example, TRAIL, for purposes of illustration. It will be appreciated that this example is intended as illustrative and is not limiting in any way. Novel mutants of TRAIL have been designed in order to increase binding to the receptor DR4 (TRAIL-R1) relative to the binding to the receptor DR5 (TRAIL-R2). This selectivity/specificity would allow lower concentrations of the variants to be administered, for example in the case of use as a therapeutic, than would be used with respect to wild-type TRAIL. The skilled reader will appreciate that the methods described herein, for the stabilisation of a multimeric β sheet cytokine molecule, and for the alteration of selectivity of a multimeric β sheet cytokine molecule, may be combined. In particular, combinations between the stability variants described above can be made, giving variants with enhanced stability and altered selectivity/specificity. Such combinations of stable and receptor selective/specific cytokine molecules are included as specific aspects of the present invention. Examples of such molecules include any one of the TRAIL M1, M2, M3 and C1 mutants, combined with one or more of the D269H, E195R, T214R, D269HE195R, D269HT214R, D269K, D269R, R191ED267R, G160M, D218Y, D218H, D218K, D218R, R130E and I220M selectivity/specificity mutants, which give variants with enhanced stability and altered selectivity/specificity. A particularly preferred example is the selective and stable variant D269HM1 which has increased selectivity/specificity for DR5 (TRAIL-R2) and increased stability when compared to wild type TRAIL. Conventional experimental methodologies may be used to supplement the largely computational approach that is outlined above. For example, once amino acid substitutions have been identified, these substitutions should be produced experimentally using site-directed mutagenesis and then tested for stability or selectivity/specificity and for retention of biological activity. Identified molecules can be further mutated using conventional techniques of molecular evolution, to develop more specific therapeutic lead molecules. In the case of molecular evolution, one particularly useful technology is phage display, which when coupled with an effective biopanning strategy, and when integrated with rational design methodologies, should result in rapid molecular evolution of novel therapeutics. The invention also provides purified nucleic acid molecules which encode a mutant β sheet cytokine as described above. Further aspects of the invention include vectors, such as expression vectors, that contain such nucleic acid molecules, along with host cells transformed with these vectors. In an further aspect, the invention provides a β sheet multimeric cytokine whose sequence has been altered by a method according to any one of the aspects of the invention described above, or a nucleic acid molecule encoding such a molecule, or a vector containing a nucleic acid molecule as described, for use in the therapy or diagnosis of a disease in which cytokines are implicated. This aspect of the invention includes a method for the treatment of such a disease, comprising administering to a patient, a cytokine, nucleic acid or vector as described above, in a therapeutically-acceptable amount. Such molecules may also be used in diagnosis, for example, by assessing the level of expression or activity of a gene or protein (such as an over-expressed receptor) in tissue from said patient and comparing said level of expression or activity to a control level, wherein a level that is different to said control level is indicative of disease. A further aspect of the invention may comprise a pharmaceutical composition comprising a mutant cytokine, nucleic acid or vector as described above, in conjunction with a pharmaceutically-acceptable carrier. A still further aspect of the invention may comprise transgenic or knockout non-human animals that have been transformed to express a mutant cytokine as described above. Such transgenic animals provide useful models for the study of disease and may also be used in screening regimes for the identification of compounds that are effective in the treatment or diagnosis of disease. Importantly, the generation of mutant cytokine molecules such as those described above allows for the design of screening methods capable of identifying compounds that are effective in the treatment and/or diagnosis of diseases in which these cytokines are implicated. The interacting domains of these molecules have an intrinsic propensity to initiate signalling pathways associated with the modulation of cancer and other chronic diseases, including autoimmune disease, and are starting points for drug design. Such screening methods are included as aspects of the present invention. Various aspects and embodiments of the present invention will now be described in more detail by way of example. It will be appreciated that modification of detail may be made without departing from the scope of the invention.
|
The present invention relates to novel methods for the design of proteins, in particular, cytokines. These methods allow the stabilisation of such cytokines, as well as modification of their selectivity/specificity for their cognate receptors. The invention also relates to various modified proteins that have been designed by the methods of the invention. Cytokines are a family of growth factors secreted primarily from leukocytes, and are messenger proteins that act as potent regulators capable of effecting cellular processes at sub-nanomolar concentrations. Their size allows cytokines to be quickly transported around the body and degraded when required. Their role in controlling a wide range of cellular functions, especially the immune response and cell growth has been revealed by extensive research over the last twenty years (Boppana, S. B (1996) Indian. J. Pediatr. 63(4):447-52). These roles include immune response regulation (Nishihira, J. (1998) Int. J. Mol. Med. 2(1):17-28), inflammation (Kim, P. K. et al (2000) Surg. Clin. North. Am. 80(3):885-894), wound healing (Clark, R. A. (1991) J. Cell Biochem. 46(1):1-2), embryogenesis and development, and apoptosis (Flad, H. D. et al (1999) Pathobiology. 67(5-6):291-293). Clinical use of cytokines to date has focused on their role as regulators of the immune system (Rodriguez, F. H. et al (2000) Curr. Pharm. Des. 6(6):665-680) for instance in promoting a response against thyroid cancer (Schmutzler, C. et al (2000) 143(1):15-24). Their control of cell growth and differentiation has also made cytokines anti-cancer targets (Lazar-Molnar, E. et al (2000) Cytokine. 12(6):547-554; Gado, K. (2000) 24(4):195-209). Novel mutations in cytokines and cytokine receptors have been shown to confer disease resistance in some cases (van Deventer, S. J. et al (2000) Intensive Care Med. 26 (Suppl 1):S98:S102). The creation of synthetic cytokines (muteins) in order to modulate activity and remove potential side effects has also been an important avenue of research (Shanafelt, A. B. et al (1998) 95(16):9454-9458). Cytokine molecules have thus been shown to play a role in diverse physiological functions, many of which play a role in disease processes. Alteration of their activity is a means to alter the disease phenotype and as such, the identification of novel cytokine molecules is of significant scientific interest. Of particular interest are ligands that belong to the Tumor Necrosis Factor ligand (TNF) family; these proteins are involved in a wide range of biological activities, ranging from cell proliferation to apoptosis. Members of the TNF ligand family induce signalling pathways that lead to apoptosis or programmed cell death (PCD) through interaction with their cognate receptors. Ligand-bound receptors transmit the signal across the membrane by bringing their cytoplasmic portions into close proximity, leading to the recruitment and activation of downstream effector proteins. Apoptosis is a process fundamental to the normal development and homeostasis of multicellular organisms. However, the impairment of apoptosis regulation is implicated in the pathogenesis of cancer and several chronic diseases, including acquired immunodeficiency syndrome (autoimmune disease and AIDS) and neurodegenerative disorders (eg Parkinsons). Common examples are chronic transplant dysfunction, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD) and asthma. Molecules that mediate reversal of imbalance in signal transduction could be effective therapeutics in diseases. Members of the TNF ligand family are also master conductors of immune function and immune tolerance. There is a complex balance between immunostimulatory and immunoregulatory functions within this family that ensures appropriate immune responses. Genetic polymorphisms in the TNF ligand receptor family can result in deregulation of immune homeostasis. Such deregulation can lead to pathogenesis. The TNF family of ligands interact with their cognate receptors to trigger several signalling pathways that play key roles in regulatory and deleterious effects on immune tolerance, in addition to both protective and pathogenic effects on tissues (Rieux-Laucat et al., 2003, Current Opinion in Immunology 15:325; Mackay and Ambrose, 2003, Cytokine and growth factor reviews, 14: 311; Mackay and Kalled, 2002, Current opinion in Immunology, 14: 783-790). Examples of such proteins include ligands such as RANKL, TRAIL, and APRIL, which are implicated in disease conditions such as rheumatoid arthritis, autoimmune diabetes, systemic lupus erythematosus (SLE), Sjörgen's syndrome, experimental autoimmune encephalomyelitis (EAE), inflammatory bowel disease (IBD), autoimmune lymphoproliferative syndrome (ALPS) and multiple sclerosis. All monomeric subunits of TNF ligand family members consist of antiparallel β-sheets, organised in a jellyroll topology, and these subunits self associate in bell-shaped homotrimers, the bioactive form of the ligand. Sequence homology is highest between the (aromatic) residues responsible for trimer formation. A trimer binds three subunits of a cognate receptor, each receptor subunit binding in the grooves between two adjacent monomer subunits. The ligands are type II transmembrane proteins, but the extracellular domain of some members can be proteolytically cleaved from the cell surface, yielding a bioactive soluble form of the ligand. Recent reviews of the TNF ligand family are readily available (Locksley et al., Cell 104, 487-501 (2001); Bodmer et al., Trends Biochem. Sci. 27, 19-26 (2002)). Knowledge of members of the TNF ligand family can also be applied to other signalling pathways triggered by ligand-receptor interaction within the same and other families. Although naturally-occurring cytokines are of significant interest to the scientific community, the properties of many of these molecules do not necessarily suit their application in a clinical setting. For example, the stability of a cytokine is important throughout the production process and for the shelf-life of the final product, as well as influencing the pharmacokinetic and -dynamic properties of the protein therapeutic (Marshall et al., Drug Discov. Today 8, 212-221 (2003)). Several strategies are currently used to augment the thermal stability of proteins (Fersht, A. & Winter, G. Protein engineering. Trends Biochem. Sci. 17, 292-295 (1992); Van den Burg et al., Curr. Opin. Biotechnol. 13, 333-337 (2002)). Both rational (Pantoliano et al., Biochemistry 26, 2077-2082 (1987); Van den Burg et al., Proc. Natl. Acad. Sci. U.S.A 95, 2056-2060 (1998); Villegas et al., Fold. Des 1, 29-34 (1996)) and directed evolution methods (Giver et al., Proc. Natl. Acad. Sci. U.S.A 95, 12809-12813 (1998); Jung et al., J. Mol. Biol. 294, 163-180 (1999)) have been successfully used to improve stability. A disadvantage of a rational approach is that one can design only a limited number of potentially improved variants. In contrast, directed evolution methods allow large numbers of variants to be generated and screened. However, suitable selection/screening procedures are required, which are often not available or are very labour intensive. More recently, computational redesign algorithms have been employed to enhance stability, amongst other properties, of proteins (DeGrado et al., Annu. Rev. Biochem. 68, 779-819 (1999)). These methods combine computer design steps with in silico screening, permitting screening of a much larger sequence space than is experimentally possible with high-throughput techniques. Efficient algorithms are needed to search the vast sequence space and accurate scoring functions are required in order to rank the best designs (Dantas et al., J. Mol. Biol. 332, 449-460 (2003)). Some limited success has been achieved for certain proteins—for example, computational redesign has recently been used to generate a hyper-thermophilic variant of streptococcal Gβ1 domain protein (Malakauskas, S. M. & Mayo, S. L. Nat. Struct. Biol. 5, 470-475 (1998)), to enhance the stability of the spectrin SH3 domain (Ventura et al., Nat. Struct. Biol. 9, 485-493 (2002)) and to improve the (thermal) stability of the therapeutically interesting four helix bundle cytokines, granulocytecolony stimulation factor (G-CSF) and human growth hormone (hGH). However, the various shortcomings of these methods do not allow their widespread application. It would also be of great use were it possible to alter the selectivity/specificity of cytokines for their receptors. For example, certain members of the TNF ligand family bind more than one receptor or bind decoy receptors which lack or have truncated intracellular domains. A specific example is the tumor necrosis factor-related apoptosis inducing ligand (TRAIL; TNFSF10) Wiley et al., Immunity. 3, 673-682 (1995); Pitti et al., J. Biol. Chem. 271, 12687-12690 (1996)), which in its soluble form binds its receptors DR4 (TRAIL-R1) and DR5 (TRAIL-R2), in addition to its decoy receptors, DcR1 (TRAIL-R3), DcR2 (TRAIL-R4) and OPG. Receptors DR4 (TRAIL-R1) and DR5 (TRAIL-R2) contain the cytoplasmic Fas associated death domain (FADD), and binding of TRAIL to these receptors induces apoptosis. TRAIL also appears to be able to induce the proliferative NF-κB pathway through Tumor necrosis factor receptor associated death domain (TRADD). Having selective inducers of DR4 (TRAIL-R1) and DR5 (TRAIL-R2) signalling is likely to be of great interest, due to the presumably different cross-linking requirements of both death receptors. Depending on the cross-linking, the signalling pathway could induce the proliferative or the apoptic pathway. DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4) do not contain a death domain or contain a truncated death domain, respectively. Binding to these receptors does not induce apoptosis; on the contrary, it may actually prevent apoptosis by sequestering available TRAIL. DcR2 (TRAIL-R4) however appears also be capable of inducing the NF-κB pathway. Unlike other apoptosis inducing TNF family members, TRAIL appears to be inactive against normal healthy tissue, therefore attracting great interest as a potential cancer therapeutic (Ashkenazi et al., J. Clin. Invest 104, 155-162 (1999)). A recent significant publication has however shown that TRAIL-R3 is upregulated by p53 in breast tumour cell through use of the genotoxic drug, doxorubicin (Ruiz de Almodóvar et al., 2003, Nov. 17, Manuscript M311243200). This implies that efficacy of wild-type TRAIL may be diminished in anti-tumour therapy since it also binds the decoy receptors (that do not initiate apoptosis). Therefore, variants of TRAIL, that have altered selectivity/specificity could be direct to the pro-apoptotic receptors, DR4 (TRAIL-R1) or DR5 (TRAIL-R2) and would have ultimately improved application in cancer treatment. The TNF ligand family members, such as TRAIL, APRIL, RANKL BAFF, LIGHT, FasL and TNF-a all bind more than one receptor. At least six death-domain-containing receptors have now been identified—Fas, TNF receptor 1 (TNF-R1), death receptor 3 (DR3; also known as TRAMP, WsI, APO-3 and LARD), the two receptors for TNF-related apoptosis-inducing ligand (TRAIL) TRAIL-R1/DR4 and TRAIL-R2/DR5, and DR6. Certain member of the TNF ligand family also bind decoy receptors which lack or have truncated death domains, such as, TRAIL, which binds its decoy receptors, DcR1, DcR2 and OPG. The accumulation of recent knowledge in this area, therefore, opens new avenues for therapeutic design. In this respect, selectivity of novel molecules is of primary importance to discern the specific role of the activation of different receptors and therefore the functional effects of ligand binding to several receptors, and the concomitant influence on the pathogenesis of the associated diseases related to signal activation. Rational design permits only a relative small amount of variants to be designed. For molecular evolution/high throughput screening (HTS) methods, selection and screening methods have to be developed and large libraries of variants have to be screened. Especially for enhancement of stability there are relatively few examples of successful selection or screening methods. Directed evolution methods allow large numbers of variants to be generated and screened. However, suitable selection/screening procedures are required, which are often not available or are very labour intensive. Such methods rely on partial randomization of the DNA sequence of a particular template protein, generating millions to billions of variants. Improved variants are selected from this vast pool using an iterative selection or screening process over several rounds by employing techniques such as phage display. A patent entitled “APO-2 LIGAND/TRAIL VARIANTS AND USES THEREOF” (WO 2004/001009 A2) describing DR4 and DR5 selective TRAIL variants published on 31 Dec. 2003. A scientific paper by Kelley et al., describing related subject matter published in 2004 (Kelley, R. F. et al., e-published ahead of print Nov. 1, 2004 manuscript number M410660200v1). Using data derived from a previous performed alanine scan (Hymowitz, S. G. et al. Biochemistry 39, 633-640 (2000)), Kelley et al., constructed libraries with a size between 0.2 to 2.5 billion unique TRAIL variants. A potential disadvantage of this approach, e.g. constructing a library using positions derived from the alanine scan, is that other advantageous mutations for achieving receptor selectivity/specificity at positions not found in the alanine scan library are missed. Positions e.g. 195 and 218 were screened in the alanine scan, however mutation to alanine did not yield a clear indication for shifting selectivity and therefore those positions were not included in the library. Using phage-display, receptor selective variants were obtained, having on average ˜6 amino acid substitutions relative to wild-type TRAIL. It was concluded that to achieve receptor selectivity multiple amino acid substitutions were required. Computational design methods known in the art have only been applied to improve the stability of relatively small monomeric molecules, not to improve the stability of larger multimeric molecules. Often these designs are focused on changing amino acids in the core of the molecule. Changing residues in the core (repacking the core) does stabilise molecules to some extent, but can lead to a molten globule state. Computational design methods have also been used in the art to alter selectivity, but again only for relatively small monomeric molecules, not to improve the selectivity for binding partners of larger multimeric molecules. Furthermore, crystal structure is currently indispensable. One aspect of the present invention uses a combination of computational redesign algorithms and educated manual input to design proteins that are more stable than their wild-type counterparts. A second aspect of the invention relates to the redesign of proteins to alter their selectivity for receptor. SUMMARY OF THE INVENTION According to a first aspect of the invention, there is provided a computer-implemented method for the stabilisation of a β sheet multimeric cytokine, comprising the step of: mutating a residue in a monomer component of the multimeric cytokine protein so as to improve the free energy of the monomer or of the multimeric complex relative to the wild-type unmutated monomer component, wherein said mutated residue is non-conserved between homologous members of the cytokine family. Variants of β sheet multimeric cytokines with enhanced stability have a number of advantages, including increased in vivo and in vitro half-lives, increased yields generated during protein expression, greater stability during purification and an extended shelf-life compared to their wild-type counterparts. Stable variants of these proteins can thus be used as protein therapeutics or diagnostics. The proteins have a relatively close resemblance to the wild-type structure and this reduce the risk of immunogenicity, particularly when compared to variants stabilised by fusion tags, one currently favoured method of stabilising proteins. They also have advantages when compared to agonistic or antagonistic antibodies. In contrast to antibodies, variants can be produced in Escherichia coli and the mode of signalling more closely resembles that used by the wild-type cytokine protein. The term “multimeric cytokine” as used herein is meant to include all β sheet multimeric cytokines. Examples of such cytokines are presented in Table 6. Other examples will be known to those of skill in the art. A recent review on structure of TNF ligand family is available (Bodmer et al., 2002. Trends Biochem. Sci. 27, 19). One feature of β sheet multimeric cytokines is that they are composed of identical monomeric subunits or of different monomeric subunits. Methodologies could be applied to all cytokine protein families and more specifically to the members of the TNF ligand-receptor family. Other examples of families of proteins embraced by the superfamily of cytokines include those classed as Beta-Trefoil, Beta-sandwich, EGF-like, and Cystine knot cytokines). Of particular interest for the application of the methodology of the invention are the β sheet multimeric cytokines that are members of the tumor necrosis factor ligand family. Ligands belonging to this family are involved in a wide range of biological activities, ranging from cell proliferation to apoptosis, and they share similar structural characteristics. All monomeric subunits of these ligands consist of antiparallel β-sheets, organized in a jelly-roll topology, and these subunits self associate in bell-shaped homotrimers, the bioactive form of the ligand. A trimer binds three subunits of a cognate receptor, each receptor subunit binding in the grooves between two adjacent monomer subunits. The ligands are type II transmembrane proteins, but the extracellular domain of some members can be proteolytically cleaved from the cell surface, yielding a bioactive soluble form of the ligand. It has been found advantageous to use alignment information in order to focus the design on non-conserved residue positions. This method of protein stabilisation focuses on these non-conserved residues on the premise that conserved residues are usually retained in a family for a good reason and it is probable that any mutation of a conserved residue will decrease protein stability. On the other hand, regions with high sequence variability are tolerant to mutation and it can be expected that variants that stabilize the protein can be found in these regions. There is less evolutionary pressure for these residues to have been retained among the family members. The combined approach of the method therefore employs family alignment information and a computational design algorithm. This reduces the sequence space search for every position in the protein being studied and decreases the computing time and power necessary for the methodology. Identification of non-conserved residues can be done using any one of a number of systems known to the person of skill in the art. Such an analysis can be done by eye, but is more easily achieved using a computer-implemented alignment algorithm, such as BLAST (Altschul et al. (1990) J Mol Biol., 215(3): 403-10), FASTA (Pearson & Lipman, (1988) Proc Natl Acad Sci USA; 85(8): 2444-8) and, more preferably, PSI-BLAST (Altschul et al. (1997) Nucleic Acids Res., 25(17): 3389-402), ClustalW (Thompson et al., 1994, NAR, 22(22), 4673-4680) or the like. Assessment of whether or not a residue is conserved will be clear to the skilled reader and will depend on the number of related proteins that are aligned and the degree of relatedness amongst them. For example, if only two family members are aligned and these proteins share 50% identity, then the conserved residues are those that are shared between the two proteins at the same positions. On the other hand, if 20 proteins in the same family are aligned, it is most unlikely that the least alike of these proteins will possess homology as high as this. Preferably, then, in an alignment between the candidate for mutation and representative members of the protein family, a conserved residue is one that is shared between at least 20% of the family, preferably at least 30%, preferably at least 40%, preferably at least 50%, and may be at least 60%, preferably 70% or more. For example, sequence homology in the Tumor Necrosis Factor ligand family is highest between the (aromatic) residues that are responsible for trimer formation; these residues are thus unsuitable candidates for mutation according to the methodology of the invention. Once non-conserved residues are identified, the next step in the method requires an evaluation of which of these residues are candidates for mutation. Preferred aspects of the methodology mutate non-conserved residues that occupy positions at the surface of the monomer component in the multimeric cytokine protein structure. By doing this, the multimeric structure is stabilised as a whole. As used herein, the term “at the surface” means that the residue concerned in the monomer remains surface-exposed in the multimer complex. Such residues are solvent-exposed and thus hydrophilic in nature. Of course, surface-exposed residues will be present not only at the surface of each monomer, but will also be surface-exposed in the multimer complex. Knowledge of the position of a particular residue in the structure of a protein may come from knowledge of the structure itself, or may be derived by extrapolation from the position of the equivalent residue in the structure of a protein in the same family. Another preferred aspect of the methodology is to mutate non-conserved residues near positions close to the interface between two monomer components of the multimeric cytokine protein structure. This has the effect of stabilising the multimeric structure of the protein through stabilisation of the inter-chain interfaces. As used herein, the term “near positions close to the interface between two monomer components” means that the residue concerned in the monomer is close to or at the interface formed when two monomer components of a multimeric protein complex together. The residue must be near enough to this interface for its constituent atoms to influence monomer-monomer interactions, preferably in a positive way. For hydrophobic interactions the distance may be as close as the Van der Waals' radius of subject atoms. For hydrogen bonding the distance may be from 2.7 angstrom to 3.1 angstrom, for electrostatic interaction the distance may be from 1.4 angstrom up to 12 angstrom. Such influence may be effected through, for example, polar or hydrophobic solvation energies, van der Waals' interactions, H-bond energies, electrostatics, or backbone and side chain entropies. For trimeric proteins, one preferred aspect of the methodology is to mutate residues that occupy positions along the central trimeric axis in the multimeric cytokine protein structure. This has the effect of stabilising the trimer. As used herein, the term “residues along the central trimeric axis” means that the residue concerned in the monomer is close to or at the interface formed when three monomer components of a trimeric protein complex together. As described above, the residue must be near enough to this interface for its constituent atoms to influence the confluence of the three monomer components into a trimeric complex. Most preferably, a method according to the invention mutates residues in more than one of the classes referred to above, preferably in at least two of the classes and even more preferably in all three of these classes. The methodology described here is, to the inventors' knowledge, the first time that a technique incorporating computational engineering has been applied to redesign a large (>100 amino acids) all-β-sheet protein towards a more thermally stable variant. Until recently, lack of protein structural information in relation to multimeric β sheet cytokines and their receptors made intervention on the level of signal transduction initiation (ligand-receptor interaction) unfeasible. Detailed crystal structural information is now available for many of these cytokines, together with reliable homology models. Therefore, studies on protein-protein interaction and the elucidation of mechanisms of ligand-receptor interaction and activation are now possible. For example, the following TNF ligand family members have been crystallised, either in complexed or uncomplexed forms: Human BAFF, Blys (Liu Y. et al., 2002 Cell 108(3):383-94; Oren D A. et al., 2002 Nat Struct Biol., 9(4):288-92.; Karpusas M. et al., 2002 J Mol Biol. 315(5):1145-54); human CD40L (Karpusas M. et al., 2001, Structure (Camb). April 4; 9(4):321-9); murine RANKL/TRANCE (Lam J. et al., 2001 J Clin Invest. 108(7):971-9); human TNF-a (Banner D W. et al., 1993 Cell. 1993 May 7; 73(3):431-45; Eck M J. et al., 1992 J Biol Chem., 267(4):2119-22.) human TRAIL (Mongkolsapaya J et al., 1999 Nat Struct Biol. 6(11):1048-53, Cha S S. et al., 1999, 2000 Immunity. 1999 August; 11(2):253-61. 2000 J Biol Chem. 2000 Oct. 6; 275(40):31171-7; Hymowitz S G. et al., 1999 Mol Cell. 4(4):563-71), human TNF-α (Reed C. et al., 1997 Protein Eng. 10(10):1101-7; Cha S S. et al., 1998 J Biol Chem. 1998 Jan. 23; 273(4):2153-60; Naismith J H. et al., 1996 Structure. 1996 Nov. 15; 4(11):1251-62, Naismith J H. et al., 1995, J Biol Chem. 1995 Jun. 2; 270(22):13303-7. 1996 J Mol Recognit. 1996 March-April; 9(2):113-7; Carter P C. et al., 2001 Proc Natl Acad Sci USA; 98(21):11879-84. Erratum in: Proc Natl Acad Sci USA 2001 Dec. 18; 98(26):15393). Therefore, the amino acids that make up domains representing protein-protein interaction motifs between these ligands and their respective receptors are now known. Such interacting domains in the TNF family have an intrinsic propensity to initiate signalling pathways associated with the modulation of diseases such as cancer and chronic diseases such as autoimmune disease, and are starting points for drug design. Visualisation of the structure of a candidate cytokine protein may be performed computationally using one or other of the many systems available for this task. Such systems are generally designed to import data describing a protein structure (such as a structure from the Protein Data Bank, the PDB) and convert this to a three-dimensional image. At present, the largest public depository of information relating to protein structure is the PDB database (http://www.rcsb.org/pdb), that now includes over 23,000 protein and nucleic acid structures, elucidated using methods of x-ray crystallography and nuclear magnetic resonance. Images of protein structure allow intimate analysis of the structure of a protein to evaluate the positions of each residue in the protein structure, and an evaluation of which residues participate in interactions with other moieties, such as a receptor or monomer partner. For example, in the example described herein, the structure of the TRAIL protein (Accession No. P50591; TN10_HUMAN, (SEQ ID NOs 1 and 2 herein)) is visualised using the template PDB structure 1DU3 (Cha et al., J. Biol. Chem. 275, 31171-31177 (2000)). The crystal structure at 2.2 Å resolution contains the trimeric structure of human TRAIL in complex with the ectodomain of the DR5 (TRAIL-R2) receptor. In this case, the TRAIL monomer lacks an external, flexible loop (130-146), not involved in receptor binding or in monomer-monomer interaction. Accordingly, to complete the molecule, this loop was modelled using the structure of 1D4V (2.2 Å) (Mongkolsapaya et al., Nat. Struct. Biol. 6, 1048-1053 (1999)), a monomeric TRAIL in complex with DR5 (TRAIL-R2) receptor, having the atomic coordinates of the loop. Finally, the TRAIL molecule was isolated by removing the receptor molecules from the PDB file. Already, there are computer-implemented programs that allow the prediction of protein structure ab initio, or by inference from closely-related proteins of known structure. Accordingly, for the method of the invention, it is not strictly necessary for the structure of a candidate protein to be known. A significant amount of information can be gleaned by analogy from structures of related proteins; for example, TNF ligand family members show similar trimeric structures. For example, for some β sheet multimeric cytokines, such as APRIL, there is no available structure of the complex with the receptor. However, there is generally structural information available for homologous ligands and receptors, which allows the complexes to be built by Homology Modelling. This is particularly true in those cases in which the sequence homology is higher then 40% and insertions or deletions are not found in the binding region of ligand and receptor. Visualisation of the isolated monomers, monomer-monomer interface and central core of the candidate protein will show the residues that are potential candidates for mutagenesis. In the case of design for stability mutants, in order to filter out unsuitable residues for mutagenesis, any highly conserved hydrophobic residues should be discarded from the list of potential candidates for mutagenesis. In addition, residues involved in receptor binding should be discarded in the case of design for stability mutants. These residues cannot be mutated without disrupting interactions with the receptor. The sequence space search for every position may preferably be simplified, by checking the naturally occurring amino acids in a multiple sequence alignment of proteins belonging to the family of interest, thus decreasing the computing time, and subsequently focusing on non-conserved residues. Preferably, in conjunction with a visualisation tool, a protein design algorithm is used to facilitate the identification of candidate residues for mutation. Examples of suitable algorithm include the “WHATIF” program (Vriend, (1990), J Mol Graph 8(1), 52-6, 29) or more sophisticated programs such as the algorithm “PERLA” (protein engineering rotamer library algorithm) (Fisinger S, Serrano L, Lacroix E. Protein Sci. 2001 April; 10(4):809-18). The latter, based on a rotamer library search, allows a combinatorial exploration at different positions simultaneously in the protein, and identifies the optimal sequence that improves a structural property of the protein (such as its stability). A detailed description of this algorithm is available elsewhere (Lacroix, E. Protein design: a computer based approach, Ph.D.thesis. (U. Libre de Bruxelles, 1999)) (http://ProteinDesign.EMBL-Heidelberg.DE) and its use has been previously described (Ventura et al., Nat. Struct. Biol. 9, 485-493 (2002); Fisinger et al., Protein Sci. 10, 809-818 (2001); Lopez et al., J. Mol. Biol. 312, 229-246 (2001); Reina et al., Nat. Struct. Biol. 9, 621-627 (2002)). Other suitable algorithms include 3D Jigsaw and EasyPred. Briefly, the PERLA algorithm performs strict inverse folding: a fixed backbone structure is decorated with amino acid side chains from a rotamer library. Relaxation of strain in the protein structure is achieved via the generation of subrotamers. Most terms of the scoring function are balanced with respect to a reference state, to simulate the denatured protein. The side chain conformers are all weighted using the mean-field theory and finally candidate sequences with modelled structures (PDB coordinates) are produced. In the case of a multimeric protein such as the TNF family ligand TRAIL, protein design with PERLA requires the following steps. Firstly, residues of a monomer that could establish specific interactions with the contiguous monomer must be identified and selected as described above. Secondly, side chains that contact the residues that are candidates for mutation must be identified to allow side chain movements that are necessary to accommodate the new residues introduced by the algorithm. PERLA automatically selects these residues based on a geometrical approach that takes Cα-Cα distances and the angle between Cα-Cβ vectors into consideration. Thirdly, the algorithm places the amino acid repertoire at each position selected from a set of naturally occurring amino acids in a multiple sequence alignment of the TNF ligand family, and eliminates from consideration those side-chain conformations and amino acids that are not compatible with the rest of the structure. Fourthly, all possible pair-wise interactions are explored to eliminate those combinations that are less favourable. This energy evaluation is preferably carried computationally, for example using a force field algorithm such as the program FOLD-X (Guerois et al., J. Mol. Biol. 320, 369-387 (2002)) or a modified version (Schymkowitz, J., Borg, J., Rousseau, F. & Serrano, L, “manuscript in preparation”) of this program, available at (http://fold-x.embl-heidelberg.de). The force field module of FOLD-X evaluates the properties of the structure, such as its atomic contact map, the accessibility of its atoms and residues and the backbone dihedral angles, in addition to the H-bond network and electrostatic network of the protein. The contribution of water molecules making two or more H-bonds with the protein is also preferably taken into account. FOLD-X then proceeds to calculate all force field components: polar and hydrophobic solvation energies, van der Waals' interactions, van der Waals' clashes, H-bond energies, electrostatics, and backbone and side chain entropies. Finally, an output of sequences and PDB coordinates corresponding to the best calculated solution (in terms of energy) is produced and may be ranked in terms of free energy, for instance, using FOLD-X. The resultant data files (preferably PDB files or similar) containing the mutations should then be energy-minimized. One way of doing this is by using a program such as GROMOS 43B1 as implemented in Swiss-PdbViewer v3.7b2 (Guex & Peitsch; Electrophoresis 18, 2714-2723 (1997)), and evaluated by FOLD-X (http://fold-x.embl-heidelberg.de). The final energies of the models are then compared to the reference, wild-type structure and expressed as ?? G (kcal mol−1). Favourable mutations may of course be combined and evaluated in terms of free energy (kcal mol-1). Unfavourable combinations (e.g. high Van der Waals' clashes) should be eliminated. If necessary, outputs of sequences and co-ordinates may subsequent to the design process be reintroduced in the design algorithm for a further round or rounds of design. 2nd, 3rd, 4th, 5th or more rounds of design may be used. The above methodology facilitates the calculation of free energy, which must be improved by mutation of the monomer, relative to the free energy of wild-type unmutated monomer. By “free energy” is meant the free energy of folding. By “free energy of folding” is meant the difference in Gibbs energy (including enthalpic and entropic terms) between the protein in a folded or partially folded state and the protein in its fully denatured state. In calculating the free energy of folding, the calculation should take into account factors such as the accessibility of atoms, the existence of hydrogen bonds and the existence of electrostatic charges between atoms that are predicted to occur in the folded structure, the van der Waals' interactions, the solvation, the main chain and side chain entropic effects being also taken into account. These atomic energetic calculations are then summed. This calculation should thus ideally take account of the nature of the stabilising interactions that compete with or favour the topological constraints that are inherent in a particular protein folding pathway, taking sequence considerations into account when calculating the main chain, the side chain and the loop entropic costs and the favourable contributions to protein stability. Such a method thus should incorporate detailed energetic functions that effectively estimate the balance between topological constraints (entropic origin) on the one hand and interactions stabilising a fold, on the other. The free energy of a particular protein may be assessed using any suitable method, as will be clear to the skilled reader. A number of suitable computer programs exist for the automated calculation of free energy; one preferred program is the FOLD-X program (Guerois R, Nielsen J E, Serrano L., J Mol Biol. 2002 Jul. 5; 320(2):369-87) which uses optimal energy functions to rank sequences according to their fitness for a given fold. Such molecules identified herein specifically interfere at the ligand receptor family interface where apoptosis or autoimmune signalling pathways are triggered. A combined methodology that utilises the design approach outlined above in conjunction with such experimental techniques, is included as an aspect of the present invention. Molecules generated using the above methods may also be used to elucidate the mechanism of action of β sheet multimeric cytokines. For example, although the crystal structures of TNF family members are known, little is known of the exact mechanism of binding and signal initiation by the ligand-receptor complex. Several TNF ligand family members, such as TRAIL, APRIL and RANKL, bind more than one receptor type which depending on receptor type may or may not trigger signal transduction pathways. Many questions therefore still exist with respect to molecular regulation of diseases such as cancer or autoimmune disease on the level of ligand-receptor complex formation and subsequent initiation of signal transduction. In vitro and in vivo studies aimed at the characterisation of this complex should add to a better understanding of the underlying (patho) physiological response and will aid in creating unique lead molecules. Use of these lead compounds will facilitate the elucidation of more complex basic questions in relation to protein-protein interaction, signal transduction pathways and bioactivity in in vitro and in vivo situations. In particular, protein or peptide mimetics generated may act as receptor agonists, antagonists, which may be engineered to have increased or decreased structural stability, receptor binding selectivity and/or bioactivity. In particular, such compounds have utility in the regulation of apoptosis. Members of the TNF ligand family induce signalling pathways that lead to apoptosis or programmed cell death (PCD) through interaction with their cognate receptors. Ligand-bound receptors transmit the signal across the membrane by bringing their cytoplasmic portions into close proximity, leading to the recruitment and activation of downstream effector proteins. Apoptosis, the mechanism whereby multicellular organisms dispose of superfluous or damaged cells in a controlled manner, is a process fundamental to the normal development and homeostasis of multicellular organisms. However, the impairment of apoptosis regulation is implicated in the pathogenesis of cancer and several chronic diseases, including acquired immunodeficiency syndrome (autoimmune disease and AIDS) and neurodegenerative disorders (eg Parkinsons). Common examples are chronic transplant dysfunction, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD) and asthma. Molecules that mediate reversal of imbalance in signal transduction could be effective therapeutics in diseases. Cell induced apoptosis is mediated chiefly by members of the TNF ligand family that interact with cognate receptors to trigger apoptosis. Soluble portions of these cytokines or their receptors, or mimetics thereof, are thus attractive candidates to be used as therapeutics for a variety of diseases related to apoptosis impairment. In addition, a greater understanding of the role of TNF ligand family members may be achieved in controlling lymphocyte function, in order to identify novel targets for autoimmune therapy. Deregulated Activation-Induced Cell Death (AICD) may lead and contribute to autoimmunity. Impairment of AICD leads to accumulation of auto-reactive and chronically activated T cells. These cells can express various immune modulatory ligands, including APRIL and BAFF, which can alter B cell functions, causing autoantibody secretion and finally autoimmunity. The ligation of the TNF receptor family members may either lead to apoptosis through caspase-8/10 activation or, alternatively proinflammatory reactions, cell proliferation and differentiation through activation of NFkB. Activated T cells express a wide range of TNF ligand-receptor family members, all having different effects on lymphocyte fate. APRIL acts as a co-stimulator of T and B cells and enhances T cell survival in autoimmune disease. BAFF is essential for B cell T1 to T2 stage maturation, and thus, immunoglobulin secretion. RANKL initiates differentiation of osteoclast precursors that are responsible for bone desorption. In rheumatoid joints 40% of the leukocytes are T cells, mainly CD4+. The proportion of B cells is only 1-5%, although their contribution to chronic disease development is still great. Accumulation of these cells in inflamed joints leads to further lymphocyte activation and uncontrolled systemic immune responses. In RA, for example, one needs to target both hyper-plastic synovial cells and the immune cells accumulating in the joint capsule and also circulating in the body. TNF family members are important immune regulators through promotion of proliferation and by participating in AICD of peripheral T cells. Inhibition of endogenous TRAIL function leads to impaired AICD, proliferation of autoreactive lymphocytes and synovial cells resulting in arthritic inflammation and joint tissue destruction (Song K et al. J. Exp. Med., 2000; 191(7):1095). APRIL, on the other hand can act as a co-stimulator of T cells and is able to prolong T cell survival. By dissecting the molecular pathway of T cell activation and the cell death induced by reactivation we can understand the exact role of TNF ligand family members in autoimmunity. For example, studies of AICD human peripheral T cells may be isolated from the blood of healthy individuals. T cells can be activated by anti-CD3 and anti-CD28 antibodies, or phytohaemagglutinin and maintained in the presence of various amounts of IL-2 and/or IL-15. AICD will then be induced at various days following activation by addition of anti-CD3 monoclonal antibodies. The potential of various TNF family members to induce AICD of CD4+ or CD8+ T cell populations at various times can then be tested by addition of agonistic/antagonistic ligands such as those described herein; these will compete with signalling. Cell death in the CD4+ and CD8+ population can be tested by, for example, the 7-aminoactinomycin method (Szondy Z et al. 1998, J. Infectious. Dis. 178:1288). In addition, the requirement for IL-2 in sensitising activated T cells to TRAIL-R and Fas-mediated death will be examined. Since IL-15 was shown to inhibit AICD, we will examine whether IL-15 interferes with TNF receptor family expression of activated T cells and thus with sensitisation to AICD (Marks-Konczalik J. et al. PNAS 2000 97(21):11445-11450). Based on these findings a functional assay can be suggested to test possible deficiencies in various autoimmune patients. We will attempt to understand the function of APRIL in modulating T-cell survival. Using APRIL as a co-activator, together with anti-CD3, we will examine how it modulates TRAIL, FasL or TNF signalling, IL-2 secretion and in this way the influence on T cell survival. If TNF ligand family members or variants are shown to have an influence we will proceed to characterise these molecules in several forms of autoimmunity. According to a further aspect of the invention, therefore, there is provided a β sheet multimeric cytokine whose sequence has been altered so as to generate a more stable cytokine than the wild-type, unaltered cytokine protein. Preferably, the β sheet multimeric cytokine is generated by mutating a residue in a monomer component of the multimeric cytokine protein so as to improve the free energy of the monomer or of the multimeric complex relative to the wild-type unmutated monomer component, wherein said mutated residue is non-conserved between homologous members of the cytokine family. Multimeric cytokines included within the terms of the invention are all β sheet multimeric cytokines, as described above. Examples are presented in Table 6. Preferred multimeric cytokines according to the invention are members of the TNF ligand family (see Bodmer et al., 2002. Trends Biochem. Sci. 27, 19). A preferred TNF ligand family member is the TRAIL protein. Preferably, such a β sheet multimeric cytokine is mutated in the soluble C-terminal portion of the molecule. Examples of suitable residues for mutation are those at the following positions: a) a non-conserved residue at the surface of the monomer component of the multimeric cytokine (herein termed ‘monomer’ set); b) a non-conserved residue close to the interface between two of the monomer components of the multimeric cytokine (herein termed ‘dimer’ set); c) for trimeric cytokines, a non-conserved residue along the central trimeric axis (herein termed ‘trimer’ set). This list is not exhaustive—various miscellaneous mutations may also be made dependent on the particular cytokine, that do not fall into any of the three categories above. The identification of non-conserved residues is described above. Similarly, identification of residues that fall into the above classes a) to c) is also described above. Preferably, a mutation in category a) falls in the external loop that connects that C and D anti-parallel beta strands of the cytokine (the CD loop), following the notation according to Eck (Eck et al., J. Biol. Chem. 267, 2119-2122 (1992)). Preferred examples of such mutations in the TRAIL protein include positions E194 and I196. Equivalent mutations in other β sheet multimeric cytokines will be apparent to those of skill in the art. Preferably, mutations introduced at these residues are E194I and/or I196S. In the TRAIL protein, when both these mutations are made, this has been found to result in a large improvement of free energy compared to wild-type TRAIL (ΔΔG=−9.7 kcal mol−1 monomer−1). This high energy value is due to the fact that a trimer is being studied, in addition to the presence of significant van der Waals' clashes in the crystal structure (˜5 kcal mol−1 monomer−1), which are removed upon mutation. Preferably, mutations are made at both positions E194 and I196; more preferably, both the mutations E194I and I196S are made. The predicted increase in stability of this double mutant (herein termed M1) can be explained since Glu 194 is surrounded by hydrophobic groups (Trp 231, Phe 192, Ala 235) and the carboxyl group is uncompensated. The mutation Glu 194 to Ile rectifies this situation by replacing the charged residue for a medium-sized hydrophobic residue. Conversely, Ile 196 is surrounded by polar residues (Asn 202, Lys 233) and is very close to the backbone, resulting in probable van der Waals' clashes. Mutation to Ser avoids clashes and allows formation of a hydrogen bond to Asn 202, located in the opposite part of the CD loop. Both mutations improve polar solvation energy, in addition to ameliorating side chain and backbone entropy. Preferably, a mutation in the dimer set may be made at one or more of the following positions: 125, 163, 185, 187, 232, 234, 237, 203, 205, 239, 241, 271 and 274. In the TRAIL protein, the residues at these positions are the following: H125, F163, Y185, Q187, S232, D234, Y237, D203, Q205, L239, S241, E271 and F274. The skilled reader will be able to identify equivalent positions in other β sheet multimeric cytokine proteins, for example, by multiple alignment or by structural alignment. Preferred mutations in this class include mutations at D203, Q205 and Y237. Preferably, mutations introduced at these positions are one or more of D203I, Q205M and Y237F. More preferably, two or all three of these mutations are made. A mutant TRAIL protein comprising these three mutations is herein termed M2. The design of M2 leads to the creation of a hydrophobic cluster to stabilize the interaction between residues 203 and 205 (D strand) of one monomer, and residue 237 (F strand) of the adjacent monomer. Gln 205 and Tyr 237 together form an intermolecular hydrogen bond, and Asp 203 points to a gap in the monomer-monomer interface. Mutation to Ile (203), Met (205) and Phe (237) breaks the Q205-Y237 hydrogen bond, but facilitates the tight packing of these residues, improving van der Waals' interactions, hydrophobic and polar solvation energies of the entire TRAIL molecule, without a further increase of van der Waals' clashes. Preferably, a mutation in the trimer set may be made at one or more of the following positions: 227, 230 and 240. In the TRAIL protein, the residues at these positions are the following: R227, C230 and Y240. The skilled reader will be able to identify equivalent positions in other β sheet multimeric cytokine proteins. A preferred mutation in this class is R227M. A mutant TRAIL protein comprising this mutation is herein termed M4. The Arg 227 residues of mutant M4 are located in strand E, equidistantly opposed in a central position along the longitudinal axis of the TRAIL trimer. The three arginines are surrounded by hydrophobic (Ile 242), polar (Ser 241, Ser 225) and aromatic (Tyr 240, Tyr 243) residues. These tyrosines direct the hydroxyl groups away from Arg 227, thus creating a rather hydrophobic cavity. The high concentration of positive charges is apparently not well compensated, since it forms only hydrogen bonds with the backbone (carbonyl groups of Ser 241). Thus, the mutation of these positions to Met could help to accommodate the hydrophobic environment, as well as to decrease the repulsion of monomers due to uncompensated positive charges. Also the combination of C230S and Y240 is preferred. Replacement of the Cys 230 with Ser removes a zinc binding site thereby introducing unfavourable interactions. The second mutation (Y240F) removes unfavourable interactions to restore thermal stability and biological activity. Preferably, a mutation in the miscellaneous set may be made at one or more of the following positions: 123, 272, 225, 280, 163, 123 and 208. In the TRAIL protein, the residues at these positions are the following: A123, A272, S225, V280, F163, A123 and V208. The skilled reader will be able to identify equivalent positions in other β sheet multimeric cytokine proteins. A preferred mutation in this class is S225A. A mutant TRAIL protein comprising this mutation is herein termed M3. Residue 225 of M3 (S225A) is located in strand E and is solvent exposed in the monomeric form. However, after trimerization, this position becomes buried in a small pocket, leaving the side chain of the hydrogen bond donor Ser uncompensated. After mutation to Ala, the energy of the model is better than wild-type TRAIL for both polar and hydrophobic solvation energies, in addition to side chain entropy. A further preferred mutant β sheet multimeric cytokine is one which incorporates a combination of the mutations described above, such as 2, 3, 4, 5, 6, 7, 8, 9, 10 or more such mutations. One example of such a mutant combines mutations at positions 194, 196 and 225. In the TRAIL protein, the residues at these positions are E194, I196 and S225. Preferably, the mutations introduced are E194I, I196S and S225A; a TRAIL mutant containing these three mutations has been engineered and is referred to herein as C1. The above mutations may be introduced in the full length cytokine sequence. Preferably, however, the above mutations are introduced into soluble forms of β sheet multimeric cytokines. For the TRAIL protein, a preferred soluble template into which these mutations may be introduced comprises amino acids 114-281 of the full length TRAIL protein. However, as the skilled reader will appreciate, variations in this template will very likely retain the properties of this soluble form and show biological activity if additional residues C terminal and/or N terminal of these boundaries in the polypeptide sequence are included. For example, an additional 1, 2, 3, 4, 5, 10, 20 or even 30 or more amino acid residues from the wild-type cytokine sequence, or from a homologous sequence, may be included at either or both the C terminal and/or N terminal of these boundaries, without prejudicing the ability of the polypeptide fragment to fold correctly and exhibit biological activity. Similarly, truncated variants of this template in which one or a few amino acid residues (for example, 1, 2, 3, 4, 5, 10 or more) may be deleted at either or both the C terminus or the N terminus without prejudicing biological activity The methods described above have been applied to a prototypic example, TRAIL, for purposes of illustration. It will be appreciated that this example is intended as illustrative and is not limiting in any way. Novel mutants of TRAIL have been designed in order to increase the stability of the bioactive trimer. As will be evident from the Examples included herein, using this approach succeeded in extending the apparent thermal stability of the β-sheet protein by more than 5° C. This correlates with the preservation of overall structural characteristics as highlighted by the lasting bioactivity of these mutants as tested experimentally. For example, when measuring the residual bioactivity of wild-type TRAIL and TRAIL mutants upon incubation at 73° C. for 1 hour, it was shown that, while wild-type TRAIL was all but thermally inactivated after ˜20 min, the TRAIL mutants M1, M2, M3 and C1, significantly, had an improved stability. Although not tested herein, it has been shown that in case of certain therapeutically interesting proteins, improvement of thermal stability can also be indicative of an improved in vivo half-life (Luo et al., Protein Sci. 11, 1218-1226 (2002); Filikov et al., Protein Sci. 11, 1452-1461 (2002)). Furthermore, the increase in thermal stability did not affect the biological activity of M1, M3 and C1. Significantly, it is shown herein that stabilisation of the CD loop in a single monomer resulted in stabilisation of the entire trimeric molecule. As stated above, it would be desirable were it to be possible to alter the selectivity/specificity of cytokines for their cognate receptors. The inventors have now achieved, for the first time, the alteration of the receptor binding selectivity/specificity of a large multimeric protein structure using computational redesign. Automated computer algorithms have been used in combination with hand-crafting and selection of pertinent residues to alter receptor binding selectivity of a multimeric all β-sheet protein, TRAIL. Accordingly, this aspect of the invention provides a method for the alteration of the selectivity of a β sheet multimeric cytokine for a target receptor, the method comprising identifying amino acids in the cytokine that are located in the receptor-binding interface as candidates for mutation; discarding residues interacting with amino acids that are conserved among receptors bound by the cytokine protein; discarding residues interacting with the receptor backbone; and substituting each of one or more residues in the cytokine protein for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity of the cytokine protein for that target receptor. Alternatively, one or more residues in the cytokine protein may be substituted for replacement residues so as to decrease the binding affinity of the cytokine protein for a particular target receptor. The invention also provides a β sheet multimeric cytokine that is obtained or obtainable by the above methodology. The invention also provides a β sheet multimeric cytokine with selectivity for a target receptor, wherein one or more amino acids in the cytokine that are located in the receptor-binding interface are substituted for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity and selectivity/specificity of the cytokine protein for that target receptor, provided that these are not residues interacting with amino acids that are conserved among receptors bound by the cytokine protein. Alternatively, the invention provides a β sheet multimeric cytokine with selectivity for two or more target receptors wherein selectivity for a first target receptor is achieved by substituting one or more amino acids in the cytokine for replacement residues so as to decrease affinity for one or more different target receptors, provided that these are not residues interacting with amino acids that are conserved among receptors bound by the cytokine protein. The target receptors referred to herein may be cognate receptors. As discussed above, alteration of selectivity for receptor is of significant interest in the cytokine field. For example, TNF ligand family members bind to receptors of the TNF receptor family, and upon binding an intracellular signalling cascade is activated. Different cell subtypes have different profiles of TNF receptor family expression. Many TNF ligand family members can signal through more than one type of TNF receptor family member proteins, resulting in different biological activities, depending on the receptor and the expression profiles of these receptors on the cell surface. For a protein therapeutic/diagnostic it may be advantageous to selectively activate (or inhibit) one of the receptors, for example to differentiate between a cell-proliferating activity and a cell-death inducing activity. Using the method of the invention described above, this is now possible even for large multimeric molecules. Furthermore, an improved selectivity/specificity would allow lower concentrations of a therapeutic variant to be administered than would be necessary with respect to wild-type cytokine. Such selective variants of cytokines are advantageous for use as protein therapeutics or diagnostics, since they exhibit a relatively close resemblance to the wild-type structure and this reduces the risk of immunogenicity. They also have advantages when compared to agonistic or antagonistic antibodies. In contrast to antibodies, variants can be produced in Escherichia coli and the mode of signalling resembles the wild-type mode of signalling more closely. According to the method of this aspect of the invention, selectivity for receptor is of primary importance. Accordingly, affinity for a receptor may be slightly compromised for improvements in selectivity/specificity. Using a method such as that described herein, novel mutants of the TRAIL protein have been designed in order to shift selectivity/specificity towards its different membrane receptors (DR4 (TRAIL-R1), DR5 (TRAIL-R2), DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4)). As described above, having selective inducers of DR4 (TRAIL-R1) and DR5 (TRAIL-R2) signalling is of considerable interest, due to the different cross-linking requirements of both death receptors. Depending on the cross-linking the signalling pathway could induce the proliferative or the apoptic pathway. Some residues important for binding and biological activity have been already identified in TRAIL by alanine-scanning mutagenesis (Hymowitz et al., Biochemistry. 2000 Feb. 1; 39(4):633-40), but in this study, the inventors have focused not only in the identification of critical residues for selectivity, also have suggested the best amino acid substitution at these positions to get a maximum effect in selectivity. We show that some residues are critical for receptor binding and selectivity; alanine-scanning mutagenesis could not identify these. The results also confirm that the choice of amino acid chosen for replacement is important. This example acts as a prototypic example of how the method of the invention may be applied to a large multimeric β sheet protein. As the skilled reader will be aware, methods used in this study are also applicable to other multimeric cytokines, such as TNF family ligands. For example, a recent significant publication has shown that TRAIL-R3 is upregulated by p53 in breast tumour cell through use of the genotoxic drug, doxorubicin (Ruiz de Almodóvar et al., J. Biol. Chem 6; 279(6):4093-101 (2003). This implies that efficacy of wild-type TRAIL may be diminished in anti-tumour therapy since it also binds the decoy receptors (that do not initiate apoptosis). Therefore, variants of TRAIL, that have altered selectivity/specificity could be directed to the pro-apoptotic receptors, DR4 (TRAIL-R1) or DR5 (TRAIL-R2) and would have ultimately improved application in cancer treatment. Methods for identifying amino acids that are located in the receptor-binding interface are known in the art. Preferably, this is done through visualisation of the structure of the ligand protein, ideally in complexed form with receptor, using one or other of the many systems available. Such systems are generally designed to import data describing a protein structure (such as a structure from the Protein Data Bank, the PDB) and convert this to a three-dimensional image. Images of protein structure allow intimate analysis of the structure of the protein to evaluate the positions of each residue in the protein structure, and an evaluation of which residues participate in interactions with other moieties, such as a receptor or monomer partner. Selected side chains are those in the protein ligand that are physically close enough to be potentially interacting with receptor. If no protein structure is available, it is likely that there will be structural information available for one or more homologous ligands and receptors, which allows the complexes to be built by Homology Modelling. This is particularly true in those cases in which the sequence homology is higher then 40% and insertions or deletions are not found in the binding region of ligand and receptor. For example, in the specific case of alteration of the selectivity of the TRAIL protein for DR5 (TRAIL-R2) or towards DR4 (TRAIL-R1), a crystal model of TRAIL in complex with the ectodomain of the DR5 (TRAIL-R2) receptor is available (PDB identifier 1DU3). Models of TRAIL complexed with the three other membrane receptors (DR4 (TRAIL-R1), DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4)) may be obtained using the “What If Homology Modeling web interface” (Vriend. WHAT IF: A molecular modeling and drug design program. J Mol. Graph. (1990) 8, 52-56) (available at http://www.cmbi.kun.nl/gv/servers/WIWWWI/). Pdb files of TRAIL in complex with these three receptors can be generated by imposing their backbone atoms over the same atoms of the receptor DR5 (TRAIL-R2), using a program such as Swiss-PdbViewer v3.7b2 (Guex & Peitsch. SWISS-MODEL and the Swiss-PdbViewer: an environment for comparative protein modeling. Electrophoresis 18, 2714-2723 (1997)). Finally, template receptor DR5 (TRAIL-R2) is removed from the generated PDB file. In a similar manner to the method of protein stabilisation described above, it is considered advantageous to use alignment information in order to focus the design on residues that do not interact with conserved residue positions in the target receptor. On occasion, however, altering conserved residues may also lead to changes in selectivity for the receptor. By conserved residue positions, is meant residues that are conserved between the different receptors that bind to the protein of interest. For example, the TNF ligand family TRAIL binds to four different membrane receptors (DR4 (TRAIL-R1), DR5 (TRAIL-R2), DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4)). Residues in the receptor binding interface that are conserved between the different receptors are likely to contribute to the binding of the ligand protein, meaning that their alteration would very likely disrupt important ligand-receptor interactions that are necessary for effective ligand-receptor binding. For the same reason, any residues that are predicted to interact with the receptor backbone are not considered suitable candidates for mutation. As described above, identification of non-conserved residues can be done using any one of a number of systems known to the person of skill in the art, but preferably, computer-implemented alignment algorithms such as PSI-BLAST or ClustalW are preferred. The combined approach of the method therefore employs family alignment information and a computational design algorithm. This reduces the sequence space search for every position in the protein being studied and decreases the computing time and power necessary for the methodology. This methodology allows rational design of the occurring interactions between the protein ligand and its receptors. An overall visual inspection of the binding interface of ligand with the different receptors should also be carried out and, if necessary, some rotamers changed. The method requires that each of one or more residues in the ligand protein are substituted for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity for that receptor. This step is preferably performed using a computer design algorithm such as PERLA, which performs inverse folding. Briefly, this algorithm decorates a fixed backbone structure with amino acid side chains from a rotamer library. PERLA thus performs a rotamer search looking for better side chain conformations, aiming to model the expected interactions of the protein ligand with its receptors. Relaxation of strain in the protein structure is achieved via the generation of subrotamers. Most terms of the scoring function are balanced with respect to a reference state, to simulate the denatured protein. The side chain conformers are all weighted using the mean-field theory and finally candidate sequences with modelled structures (PDB coordinates) are produced. Energy evaluation of the modelled structure must also be performed as part of this methodology, preferably using a program such as FOLD-X7 or an improved version (such as that available at http://fold-x.embl-heidelberg.de). The force field module of FOLD-X evaluates the properties of the structure, such as its atomic contact map, the accessibility of its atoms and residues, the backbone dihedral angles, in addition to the H-bond network and electrostatic network of the protein. The contribution of water molecules making two or more H-bonds with the protein is also taken into account. FOLD-X then proceeds to calculate all force field components: polar and hydrophobic solvation energies, van der Waals' interactions, van der Waals' clashes, H-bond energies, electrostatics, and backbone and side chain entropies. Using this program, all possible amino acid substitutions (preferably with the exception of Glycine, Proline, and Cysteine) are then introduced at the selected residue positions in the protein ligand in conformations (side chain rotamers) that are compatible with the rest of the structure. Glycine, Proline, and Cysteine are preferably omitted because Gly and Pro can influence the backbone conformation relatively more than other amino acids (Gly is more flexible, Pro less so). Also these residues have relatively large effects in the denatured state (Gly high entropy, Pro lower). Cys can also be difficult and is in an unpaired state that is generally unwanted in proteins, making them prone to aggregation and the like. Favourable mutations are then evaluated in terms of free energy (kcal mol-1), and unfavourable mutations (e.g. high Van der Waals' clashes) eliminated. An output of sequences and coordinates is then obtained and ranked in terms of free energy, for example, using the FOLD-X program. Some of these predictions can be discarded directly after theoretical energy calculations, without further experimental analysis. Others are progressed to mutagenesis studies. In this way, the method of this aspect of the invention substitutes one or more residues in the ligand protein substituted for replacement residues that include amino acid side-chain conformations that are predicted to fit into the binding interface with the target receptor so as to provide an increase in binding affinity for that target receptor. Favourable mutations may of course be combined and evaluated in terms of free energy (kcal mol-1). Unfavourable combinations (e.g. high Van der Waals' clashes) should be eliminated. If necessary, outputs of sequences and co-ordinates may subsequent to the design process be reintroduced in the design algorithm for a further round or rounds of design. 2nd, 3rd, 4th, 5th or more rounds of design may be used. Preferably, the method of this aspect of the invention may be applied to multimeric β sheet cytokines. Examples of such cytokines are presented in Table 6. Other examples will be known to those of skill in the art. Of particular interest for the application of the methodology of the invention are the β sheet multimeric cytokines that are members of the tumor necrosis factor ligand family. Ligands belonging to this family are involved in a wide range of biological activities, ranging from cell proliferation to apoptosis, and they share similar structural characteristics. According to a further aspect of the invention, there is provided a β sheet multimeric cytokine whose sequence has been altered so as to alter its affinity for a particular target receptor. Accordingly, one aspect of the invention relates to a cytokine that is mutated at one, two, three, four, five, six, seven, eight, nine, ten, eleven or all twelve of these positions. Preferably, such a cytokine is a member of the TNF ligand family. More preferably, such a cytokine is TRAIL (SEQ ID NO:1 herein). All references to amino acid positions in the TRAIL protein sequence presented herein, and to specific TRIAL mutants are intended to refer to the amino acid sequence given in SEQ ID NO:1. Preferably, the TRAIL sequence is altered so as to alter affinity and/or selectivity for the DR4 (TRAIL-R1) or DR5 (TRAIL R2) receptors. Examples of suitable residues for mutation in TRAIL are those at the following positions: 131, 269, 130, 160, 218, 220, 149, 155, 214, 195, 191 and 267. Equivalent residues (when crystal structural information is compared by eye or with use of molecular modelling) identified by those skilled in the art could be mutated in other β sheet multimeric cytokines, preference being for the cytokines of the TNF family. Equivalent substitutions at the above positions, with a specific type of residue are preferred. For example, a preferred mutation at position 131 is to Arg. Preferred mutations at position 269 are to His, Lys or Arg. A preferred mutation at position 130 is to Glu. Preferred mutations at position 160 are Lys and Met. Preferred mutations at position 218 are to Arg, Tyr, Glu, Phe, Lys or His. Preferred mutations at position 220 are to Met or to His. Preferred mutations at position 149 are to Asp or to His. A preferred mutation at position 155 is to Met. A preferred mutation at position 214 is to Arg. A preferred mutation at position 195 is to Arg. A preferred mutation at position 191 is to Glu. A preferred mutation at position 267 is to Arg. In the TRAIL protein, preferred mutations are G131R, D269H, D269K, D269R, R130E, G160K, D218R, G160M, D218Y, D218E, D218K, D218H, I220M, I220H, R149D, R149H, D218F, E155M, T214R, E195R, R191E and D267R. Particularly preferred TRAIL mutants are G160M, D269H, D218Y, R130E and I220M. In particular, the G160M, D269H, D269K, D269R, T214R and E195R mutants are preferred as these are shown herein to have superior selectivity for the death receptor 5. Some critical residues identified in TRAIL for receptor binding without distinction between DR4 and DR5 (TRAIL-R2) have been identified as Ile 220, Arg 149, Glu 155, Gly 160 and Asp 218. The I220H and I220M mutants both highly increase DR4 binding, and have no effect on DR5 binding. The R149D mutant decreases binding to both the DR4 and DR5 receptors, whilst the R149H and D218R mutants have no effect on binding to either of these receptors. The E155 mutant highly decreases binding to both the DR4 and DR5 receptors; the D218F and D218Y mutants also decrease affinity, although to a lesser extent. Furthermore, the D218Y mutant demonstrates a larger decrease in DR5-affinity than DR4-affinity. Whereas wild type TRAIL has a higher affinity for DR5 than DR4, this preference is lost in the mutant and the overall effect of the D218Y mutation is to shift selectivity towards DR4 (TRAILR1). In the same way, the D218K, D218R, D218E and D218H mutants have superior selectivity for DR4 (TRAIL-R1). Also, it has been shown that different amino acid substitutions in the same position can have a different effect on receptor binding. Some positions, critical for receptor selectivity, due to a different decrease in receptor binding affinity between DR4 (TRAIL-R1) and DR5 (TRAIL-R2) have been identified as Arg 130, Gly 131 and Asp 269. The R130E and G131R mutants decrease binding to DR4 but only slightly decrease binding to DR5. In contrast, the D269H mutant highly decreases binding to DR4. Initial experiments shows that the D269H mutant had no observable effect on binding to DR5, although more recent experiments confirm that in fact this mutant significantly increases binding to DR5. The same receptor binding preferences are demonstrated by variants D269K and D269R. The skilled reader will be able to identify equivalent positions in other β sheet multimeric cytokine proteins, for example, using multiple alignment programs or manual inspection of related sequences or structures. Preferably, affinity for receptor is improved for DR4 (TRAIL-R1) or DR5 (TRAIL-R2) over the affinity for the decoy receptors DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4). More preferably still, affinity for DR5 (TRAIL-R2) receptor is improved over affinity for DR4 (TRAIL-R1). Alternatively, affinity for DR4 (TRAIL-R1) receptor is improved over affinity for DR5 (TRAIL-R2). The above mutations may be introduced in the full length cytokine sequence. Preferably, however, the above mutations are introduced into soluble forms of β sheet multimeric cytokines. For the TRAIL protein, a preferred soluble template into which these mutations may be introduced comprises amino acids 114-281. Equivalent soluble forms of other cytokines will be clear to the skilled reader. However, as the skilled reader will appreciate, variations in this template will very likely retain the properties of this soluble form and show biological activity if additional residues C terminal and/or N terminal of these boundaries in the polypeptide sequence are included. For example, an additional 1, 2, 3, 4, 5, 10, 20 or even 30 or more amino acid residues from the wild-type cytokine sequence, or from a homologous sequence, may be included at either or both the C terminal and/or N terminal of these boundaries, without prejudicing the ability of the polypeptide fragment to fold correctly and exhibit biological activity. Similarly, truncated variants of this template in which one or a few amino acid residues (for example, 1, 2, 3, 4, 5, 10 or more) may be deleted at either or both the C terminus or the N terminus without prejudicing biological activity. The skilled reader will appreciate that the methods described herein for the alteration of selectivity of a multimeric β sheet cytokine molecule may be combined. In particular, combinations of the selectivity/specificity mutations to give variants with enhanced selectivity. For example, variants with altered selectivity/specificity can be combined with variants with an increased selectivity/specificity. Preferably, the positions of the combined mutations are far enough away from each other so that they cannot make any predictable interaction with each other. As such, both mutations may contribute to selectivity in an independent way. Such combinations of receptor selective/specific mutations and the variants they encode are included as specific aspects of the present invention. Examples of such molecules include combinations of one or more of the D269H, E195R, T214R, D267R, D269K, D269R and R191E selectivity/specificity mutants, which give variants with enhanced selectivity/specificity. A particularly preferred example is the combination of the R191E mutation with the D267R mutation to give the R191ED267R variant. The methods described above have been applied to a prototypic example, TRAIL, for purposes of illustration. It will be appreciated that this example is intended as illustrative and is not limiting in any way. Novel mutants of TRAIL have been designed in order to increase binding to the receptor DR4 (TRAIL-R1) relative to the binding to the receptor DR5 (TRAIL-R2). This selectivity/specificity would allow lower concentrations of the variants to be administered, for example in the case of use as a therapeutic, than would be used with respect to wild-type TRAIL. The skilled reader will appreciate that the methods described herein, for the stabilisation of a multimeric β sheet cytokine molecule, and for the alteration of selectivity of a multimeric β sheet cytokine molecule, may be combined. In particular, combinations between the stability variants described above can be made, giving variants with enhanced stability and altered selectivity/specificity. Such combinations of stable and receptor selective/specific cytokine molecules are included as specific aspects of the present invention. Examples of such molecules include any one of the TRAIL M1, M2, M3 and C1 mutants, combined with one or more of the D269H, E195R, T214R, D269HE195R, D269HT214R, D269K, D269R, R191ED267R, G160M, D218Y, D218H, D218K, D218R, R130E and I220M selectivity/specificity mutants, which give variants with enhanced stability and altered selectivity/specificity. A particularly preferred example is the selective and stable variant D269HM1 which has increased selectivity/specificity for DR5 (TRAIL-R2) and increased stability when compared to wild type TRAIL. Conventional experimental methodologies may be used to supplement the largely computational approach that is outlined above. For example, once amino acid substitutions have been identified, these substitutions should be produced experimentally using site-directed mutagenesis and then tested for stability or selectivity/specificity and for retention of biological activity. Identified molecules can be further mutated using conventional techniques of molecular evolution, to develop more specific therapeutic lead molecules. In the case of molecular evolution, one particularly useful technology is phage display, which when coupled with an effective biopanning strategy, and when integrated with rational design methodologies, should result in rapid molecular evolution of novel therapeutics. The invention also provides purified nucleic acid molecules which encode a mutant β sheet cytokine as described above. Further aspects of the invention include vectors, such as expression vectors, that contain such nucleic acid molecules, along with host cells transformed with these vectors. In an further aspect, the invention provides a β sheet multimeric cytokine whose sequence has been altered by a method according to any one of the aspects of the invention described above, or a nucleic acid molecule encoding such a molecule, or a vector containing a nucleic acid molecule as described, for use in the therapy or diagnosis of a disease in which cytokines are implicated. This aspect of the invention includes a method for the treatment of such a disease, comprising administering to a patient, a cytokine, nucleic acid or vector as described above, in a therapeutically-acceptable amount. Such molecules may also be used in diagnosis, for example, by assessing the level of expression or activity of a gene or protein (such as an over-expressed receptor) in tissue from said patient and comparing said level of expression or activity to a control level, wherein a level that is different to said control level is indicative of disease. A further aspect of the invention may comprise a pharmaceutical composition comprising a mutant cytokine, nucleic acid or vector as described above, in conjunction with a pharmaceutically-acceptable carrier. A still further aspect of the invention may comprise transgenic or knockout non-human animals that have been transformed to express a mutant cytokine as described above. Such transgenic animals provide useful models for the study of disease and may also be used in screening regimes for the identification of compounds that are effective in the treatment or diagnosis of disease. Importantly, the generation of mutant cytokine molecules such as those described above allows for the design of screening methods capable of identifying compounds that are effective in the treatment and/or diagnosis of diseases in which these cytokines are implicated. The interacting domains of these molecules have an intrinsic propensity to initiate signalling pathways associated with the modulation of cancer and other chronic diseases, including autoimmune disease, and are starting points for drug design. Such screening methods are included as aspects of the present invention. Various aspects and embodiments of the present invention will now be described in more detail by way of example. It will be appreciated that modification of detail may be made without departing from the scope of the invention. BRIEF DESCRIPTION OF DRAWINGS FIG. 1. A) Side view of the TRAIL trimeric complex, showing the three monomers in red, blue and green. B) Top view of the same complex but viewed along the longitudinal axis, depicting the different sets used for design. Structure figures were generated using MOLMOL (Koradi et al., J. Mol. Graph. 14, 51-32 (1996)). FIG. 2. Binding of wild-type TRAIL (closed circle), M1 (closed box) and M2 (open circle) to DR5 (TRAIL-R2) ( . . . ) and DR4 (TRAIL-R1) (−) receptors. FIG. 3. Thermal denaturation profiles of wild-type TRAIL (closed circle), M1 (closed box), M2 (open circle), M3 (open box) and C1 (closed triangle). FIG. 4. Stability of wild-type TRAIL (closed circle), M1 (closed box), M2 (open circle), M3 (open box) and C1 (closed triangle) at 73° C. for 60 min. FIG. 5. Remaining biological activity of wild-type TRAIL, M1, M3 and C1 (from left to right) upon incubation at 73° C. during 60 min. FIG. 6. A) Comparison, between wild-type TRAIL and M1, of the local environment around residues 194 and 196. B) Comparison between wild-type TRAIL and M2. Backbones of the two adjacent monomers are in green and blue, respectively, and the backbone of the DR5 (TRAIL-R2) receptor is in grey. Hydrogen bond interactions are depicted in dashed green lines. FIG. 7. Receptor binding as a fraction of DR5 (TRAIL-R2) binding. FIG. 8. Receptor binding as a fraction of DR4 (TRAIL-R1) binding. FIG. 9. Cytotoxic potential of D269H—Annexin V staining. FIG. 10. Testing TRAIL receptor specific killing of D269H mutant—Annexin V staining. FIG. 11. DR5 (TRAIL-R2) selective killing by D269H—Annexin V staining. FIG. 12. D269H and TRAIL have comparable cytotoxic potential. A, cells treated with TRAIL and D269H for 2 h; B cells treated for 3 h (B). The graph shows a representative of 2 independent experiments. FIG. 13. Neutralisation of DR5, but not DR4 was able to block cell death induced by D269H. FIG. 14. Receptor binding to DR4 (TRAIL-R1) Fc and DR5 (TRAIL-R2) Fc of purified wild-type TRAIL (wt1) and various purified mutants at a concentration of 60 nM. FIG. 15. Panel A & B: Binding to DR5 (TRAIL-R2) Fc; Panel C & D: Binding to DR4 (TRAIL-R1) Fc. Wild-type TRAIL: box (open); D269H: circle (closed); D269HT214R: Triangle (Up&Open); D269K: diamond (closed); D269R: diamond (open); D269HE195R: Triangle (down&Open) FIG. 16. Panel A: Binding of wild-type TRAIL (wt) and R191ED267R to DR5 (TRAIL-r2) Fc; Panel B: Binding of wild-type TRAIL (wt) and R191ED267R to DR4 (TRAIL-R1) Fc; Panel C: Binding of D218Y to DR4 (TRAIL-R1) Fc and DR5 (TRAIL-R2) Fc. FIG. 17. Competition ELISA. Panel A&B: Titration (blocking) with DR5 (TRAIL-R2) Fc; Panel C&D: Titration (blocking) with DR4 (TRAIL-R1) Fc. Wild-type TRAIL: box (open); D269H: circle (closed); D269HT214R: Triangle (Up&Open); D269K: diamond (closed); D269R: diamond (open); D269HE195R: Triangle (down&Open) FIG. 18. Panel A: Receptor binding of wild-type TRAIL and D269H to DcR1 (TRAIL-R3) Fc: Panel B: Competition ELISA. Titration with DcR1 (TRAIL-R3) Fc. Wild-type TRAIL: box (open); D269H: circle (closed); D269HT214R: Triangle (Up&Open); D269HE195R: Triangle (down&Open) FIG. 19. Panel A: Induction of Apoptosis in Colo205 cells by wild-type TRAIL and D269H, D269HE195R and D269HT214R mutants and blocking of apoptosis with neutralizing anti-DR4 and anti-DR5 antibodies. Panel B: Induction of Apoptosis in ML-1 cells by wild-type TRAIL and D269H, D269HE195R and D269HT214R mutants and blocking of apoptosis by addition of neutralizing anti-DR4 and/or anti-DR5 antibodies. FIG. 20. A: Side view of TRAIL receptor-binding interface formed by two monomer units (third monomer, not involved in this receptor-binding interface, stays behind these two monomers; receptor binds in front of them. They have been removed for a better view of the interface). TRAIL residues highlighted with Van der Waals radius were the selected residues for the in silico mutagenesis scanning. B: Most significant predicted shifts in TRAIL-receptor binding affinity of single mutants in position 269. D269E is added for comparison. C: Most significant predicted shifts in TRAIL-receptor binding affinity of single mutants in position 218. D: Predicted shifts in TRAIL-receptor binding affinity of single mutants in position 214. (Panel B-D: predicted shifts are calculated using PERLA and Fold-X). FIG. 21. Panel A: Binding of wild-type TRAIL (wt) and D269HM1 to DR5 (TRAIL-R2) Fc; Panel B: Binding of wild-type TRAIL (wt) and D269HM1 to DR4 (TRAIL-R1) Fc. Panel C: Remaining biological activity of wild-type TRAIL (wt) and D269HM1 upon incubation at 73° C. for 50 min. Biological activities are calculated relative to the value observed at 0 min. EXAMPLES Example 1 Stable TRAIL Proteins Methods All reagents were of analytical grade unless specified otherwise. Isopropyl-β-D-1-thiogalactoside (IPTG), ampicillin and dithiotreitol (DTT) were from Duchefa. Chromatographic columns and media were from Amersham Biosciences. Restriction enzymes used were purchased from New England Biolabs. All other chemicals were from Sigma. Computational Design of Mutants A detailed description of the protein design algorithm, PERLA, is available elsewhere (Lacroix, E. Protein design: a computer based approach, Ph.D.thesis. (U. Libre de Bruxelles, 1999)) (http://ProteinDesign.EMBL-Heidelberg.DE) and its use has been previously described (see, for example, Ventura et al., Nat. Struct. Biol. 9, 485-493 (2002). In the case of oligomeric proteins like TRAIL, protein design with PERLA requires the following steps: Firstly, residues of a monomer that could establish specific interactions with the contiguous monomer must be identified and selected. Secondly, side chains that contact the residues to be mutated, must be identified to allow side chain movements that are necessary to accommodate the new residues introduced by the algorithm. PERLA automatically selects these residues based on a geometrical approach that takes Ca-Ca distances and the angle between Ca-Cβ vectors into consideration. Thirdly, the algorithm places the amino acid repertoire at each position selected from a set of naturally occurring amino acids in a multiple sequence alignment of the TNF ligand family, and eliminates those side chain conformations and amino acids that are not compatible with the rest of the structure. Fourthly, all possible pair-wise interactions are explored to eliminate those combinations that are less favourable. Finally, an output of sequences and PDB coordinates corresponding to the best calculated solution (in terms of energy) is produced. The resultant PDB files containing the mutations were energy minimized using GROMOS 43B1 as implemented in Swiss-PdbViewer v3.7b2 (Guex, & Peitsch. Electrophoresis 18, 2714-2723 (1997))), and evaluated by FOLD-X (http://fold-x.embl-heidelberg.de). The final energies of the models are compared to the reference, wild-type TRAIL structure and expressed as ?? G (kcal mol−1). Cloning and PCR cDNA corresponding to human soluble TRAIL (aa 114-281) was cloned in pET15B (Novagen) using NcoI and BamHI restriction sites. The N-terminal sequence encoding a His-tag and protease recognition site was therefore removed. Mutants were constructed by PCR using the Quick Change Method (Stratagene) or a modified megaprimer method (Picard et al., Nucleic Acids Res. 22, 2587-2591 (1994)). The polymerase used was Pfu Turbo supplied by Stratagene. Purified mutagenic oligonucleotides were obtained from Invitrogen. Introduction of mutations was confirmed by DNA sequencing. Expression and Purification of Wild-type TRAIL and Mutants The wild-type TRAIL and TRAIL mutant constructs were transformed to Escherichia Coli BL21 (DE3) (Invitrogen). Wild-type TRAIL and M1 were grown at a 5 l batch scale in a 7.5 l fermentor (Applicon) using 4×LB medium, 1% (w/v) glucose, 100 μg/ml ampicillin and additional trace elements. The culture was grown to mid-log phase at 37° C., 30% oxygen saturation and subsequently induced with 1 mM IPTG. ZnSO4 was added at a concentration of 100 μM to promote trimer formation. Temperature was lowered to 28° C. and the culture was grown until stationary phase. Other mutants were grown in shake flasks at a 1 l scale at 250 rpm, using a similar protocol. Protein expression was induced when the culture reached OD600 0.5 and induction was continued for 5 h. In this case, the medium used was 2×LB without additional trace elements. The isolated pellet was resuspended in 3 volumes extraction buffer (PBS pH 8, 10% (v/v) glycerol, 7 mM β-mercapto-ethanol). Cells were disrupted using sonication and extracts were clarified by centrifugation at 40,000 g. Subsequently, the supernatant was loaded on a nickel charged IMAC Sepharose fast-flow column and wild-type TRAIL and TRAIL mutants were purified as described by Hymowitz (Hymowitz et al., Biochemistry 39, 633-640 (2000)) with the following modifications: 10% (v/v) glycerol and a minimal concentration of 100 mM NaCl were used in all buffers. This prevented aggregation during purification. After the IMAC fractionation step, 20 μM ZnSO4 and 5 mM of DTT (instead of β-mercapto-ethanol) was added in all buffers. Finally, a gelfiltration step, using a Hiload Superdex 75 column, was included. Purified proteins were more than 98% pure as determined using a colloidal coomasie brilliant blue stained SDS-PAGE gel. Purified protein solutions were flash frozen in liquid nitrogen and stored at −80° C. CD Spectroscopy CD spectra were recorded on a Jasco J-715 CD spectrophotometer (Jasco Inc.) equipped with a PFD350S Peltier temperature control unit (Jasco Inc.). Rectangular quartz cuvettes with a pathlength of 0.2 cm were used. Protein samples were dialyzed against PBS pH 7.3 and adjusted to a final concentration of 100 μg/ml. Wavelength spectra were recorded between 250-205 nm using a 0.2 nm stepsize and 1 nm band-width at 25° C. Temperature scans from 25-98° C. were performed at 222 nm with a scan rate of 40° C./h. Thermal decay measurements were performed at 73° C. for 1 h at 222 nm. Bioactivity of TRAIL Mutants In Vitro Bioactivity of wild-type TRAIL and TRAIL mutants was determined using a viability assay according to the manufacturer's instructions (Celltiter Aqueous One, Promega). Colo205 human colon carcinoma cells (ATCC number CCL-222) were cultured in RPMI 1640 Glutamax containing 10% heat inactivated fetal calf serum and 100 units/ml Penicillin-Streptomycin. All reagents were supplied by Invitrogen. A concentration series of the wild-type TRAIL or TRAIL mutants was made in cell culture medium. 50 μl of each dilution was added to a 96-well tissue culture micro plate (Greiner) and 100 μl of cell suspension was added, to a final cell number of 1×104 cells/well. Mixtures were incubated for 16 h at 37° C. under a humidified atmosphere containing 5% CO2. Subsequently, 20 μl of MTS reagent was added. Cell viability was determined after 30 min incubation by measuring the absorption at 490 nm. Receptor Binding Binding experiments were performed using a surface plasmon resonance-based biosensor Biacore 3000 (Biacore AB, Uppsala, Sweden), at 25° C. Recombinant receptors were ordered from R&D systems (R&D systems, Minneapolis, Minn., USA). Immobilization of the receptors on the sensor surface of a Biacore CM5 sensor chip was performed following a standard amine coupling procedure according to the manufacturer's instructions. A reference surface was generated simultaneously under the same conditions but without receptor injection and used as a blank to correct for instrument and buffer artifacts. Purified wild-type TRAIL and TRAIL mutants were injected in two-fold at a concentration of 2 μg/ml and at a flow rate of 20 μl/min flow rate. Binding of ligands to the receptors was monitored in real-time. The receptor/sensor surface was regenerated using 3 M sodium acetate pH 5.2 injections. Computer Screening Novel mutants of TRAIL have been designed in order to increase the stability of the bioactive trimer. Predictions were based on the automated computer algorithm, PERLA, as described above. Briefly, the program performs strict inverse folding: a fixed backbone structure is decorated with amino acid side chains from a rotamer library. Relaxation of strain in the protein structure is achieved via the generation of subrotamers. Most terms of the scoring function are balanced with respect to a reference state, to simulate the denatured protein. The side chain conformers are all weighted using the mean-field theory and finally candidate sequences with modelled structures (PDB coordinates) are produced. Energy evaluation of the modelled structures was carried-out by a modified version (Schymkowitz, J., Borg, J., Rousseau, F. & Serrano, L, “manuscript in preparation”) of FOLD-X, available at (http://fold-x.embl-heidelberg.de). The force field module of FOLD-X evaluates the properties of the structure, such as its atomic contact map, the accessibility of its atoms and residues, the backbone dihedral angles, in addition to the H-bond network and electrostatic network of the protein. The contribution of water molecules making two or more H-bonds with the protein is also taken into account. FOLD-X then proceeds to calculate all force field components: polar and hydrophobic solvation energies, van der Waals' interactions, van der Waals' clashes', H-bond energies, electrostatics, and backbone and side chain entropies. Selection of the Template Sequence The template selected was 1DU3 (Cha et al., J. Biol. Chem. 275, 31171-31177 (2000)). The crystal structure at 2.2 Å resolution contains the trimeric structure of human TRAIL in complex with the ectodomain of the DR5 (TRAIL-R2) receptor. The TRAIL monomer lacks an external, flexible loop (130-146), not involved in receptor binding or in monomer-monomer interaction. To complete the molecule, this loop was modelled using the structure of 1D4V (2.2 Å) (Mongkolsapaya et al., Nat. Struct. Biol. 6, 1048-1053 (1999)), a monomeric TRAIL in complex with DR5 (TRAIL-R2) receptor, having the atomic coordinates of the loop. Finally, the TRAIL molecule was isolated by removing the receptor molecules from the PDB file. Computational Design of Mutants The visual inspection of the isolated monomers, monomer-monomer interface and central core of TRAIL showed several residues as potential candidates for mutagenesis. The highly conserved hydrophobic residues were discarded from this list, as well as residues involved in receptor binding. These residues could not be mutated without disrupting interactions with the receptor. One TRAIL variant (M2), however, that showed a significant predicted increase in stability but also contained residues involved in receptor interaction, was retained for subsequent experimental analysis. The sequence space search for every position was simplified by checking the naturally occurring amino acids in a multiple sequence alignment of proteins belonging to the TNF ligand family, thus decreasing the computing time, and subsequently focusing on non-conserved residues. The use of protein rational design and force field algorithms (PERLA, FOLD-X) allowed the identification of a list of mutant sequences with potential relevance for TRAIL stability. Four sets of residues were selected for design (FIG. 1b and Table 1): (1) non-conserved residues at the surface of the monomer (‘monomer’ set), (2) non-conserved residues near positions close to the interface between two monomers (‘dimer’ set), (3) non-conserved residues along the central trimeric axis (‘trimer’ set) and (4) a miscellaneous set (‘misc. set’). The automated computer algorithm PERLA was applied as previously described (Angrand et al., Biomol. Eng 18, 125-134 (2001)). Amino acid substitutions were introduced at the non conserved residue positions in conformations (side chain rotamers) compatible with the rest of the structure. Subsequently, favourable mutations were combined and evaluated in terms of free energy (kcal mol−1), and unfavourable combinations (e.g. high Van der Waals' clashes) were eliminated. An output of sequences and coordinates was produced and ranked in terms of free energy using FOLD-X and subsequently reintroduced in the design algorithm for a 2nd, 3rd or 4th round of design, if necessary. Table 1 summarizes the list of mutants assayed in silico for increased stability of TRAIL. Some of these predictions were discarded directly after theoretical energy calculations, without further experimental analysis. Results Description of the Tested Mutations Predicted mutants were energy minimized and subsequently analyzed with FOLD-X. The energy values obtained were compared to that of the wild-type structure and used for discrimination of candidates. Mutants were selected based on an improvement in free energy relative to wild-type TRAIL (Table 2). In the monomeric set, M1 (E194I, I196S) was selected because of the large improvement of energy compared to wild-type TRAIL (ΔΔG=−9.7 kcal mol−1 monomer−1). This high energy value is due to the fact that a trimer is being studied, in addition to the presence of significant van der Waals' clashes in the crystal structure (˜5 kcal mol−1 monomer−1), which are removed upon mutation. The mutations are located in the external loop connecting the C and D anti-parallel beta strands (CD loop), following the notation according to Eck (Eck et al., J. Biol. Chem. 267, 2119-2122 (1992)). The predicted increase in stability of M1 can be explained since Glu 194 is surrounded by hydrophobic groups (Trp 231, Phe 192, Ala 235) and the carboxyl group is uncompensated. The mutation Glu 194 to Ile rectifies this situation by replacing the charged residue for a medium sized hydrophobic residue. Conversely, Ile 196 is surrounded by polar residues (Asn 202, Lys 233) and is very close to the backbone, resulting in probable van der Waals' clashes. Mutation to Ser avoids clashes and allows formation of a hydrogen bond to Asn 202, located in the opposite part of the CD loop (FIG. 6a). Both mutations improve polar solvation energy, in addition to ameliorating side chain and backbone entropy. In the dimeric set (Table 2), the design of M2 (D203I, Q205M, Y237F) leads to the creation of a hydrophobic cluster to stabilize the interaction between residues 203 and 205 (D strand) of one monomer, and residue 237 (F strand) of the adjacent monomer. Gln 205 and Tyr 237 together form an intermolecular hydrogen bond, and Asp 203 points to a gap in the monomer-monomer interface. Mutation to Ile (203), Met (205) and Phe (237) breaks the Q205-Y237 hydrogen bond, but facilitates the tight packing of these residues, improving van der Waals' interactions, hydrophobic and polar solvation energies of the entire TRAIL molecule, without a further increase of van der Waals' clashes (FIG. 6b). Although FOLD-X predicted that the affinity of M2 for the DR5 (TRAIL-R2) receptor is lower (ΔΔGbinding=7.3 kcal mol−1 monomer−1) than for wild-type TRAIL, this mutant was retained as a control to evaluate the accuracy of the procedure. Residue 225 of M3 (S225A), belonging to the ‘Miscellaneous set’, is located in strand E and is solvent exposed in the monomeric form. However, after trimerization, this position becomes buried in a small pocket, leaving the side chain of the hydrogen bond donor Ser uncompensated. After mutation to Ala, the energy of the model is better than wild-type TRAIL for both polar and hydrophobic solvation energies, in addition to side chain entropy. The Arg 227 residues of the trimeric set mutant (M4) are located in strand E, equidistantly opposed in a central position along the longitudinal axis of the TRAIL trimer. The three arginines are surrounded by hydrophobic (Ile242), polar (Ser241, Ser225) and aromatic (Tyr 240, Tyr 243) residues. These tyrosines direct the hydroxyl groups away from Arg 227, thus creating a rather hydrophobic cavity. The high concentration of positive charges is apparently not well compensated, since it forms only hydrogen bonds with the backbone (carbonyl groups of Ser241). Thus, the mutation of these positions to Met could help to accommodate the hydrophobic environment, as well as to decrease the repulsion of monomers due to uncompensated positive charges. Mutagenesis and Purification of Mutants The highest ranking mutants M1 and M2 together with M3 and M4, were selected for further experimental analysis (Table 2). A mutant (C1) combining the mutations of M1 and M3 was also constructed. All the designed TRAIL mutants were expressed in E. coli and purified successfully with a protein yield of ˜0.7-2 mg/l. Far-UV CD wavelength spectra indicated that all mutants were properly folded with characteristics of a β-sheet containing protein, similar to that of wild-type TRAIL. Gel-filtration and dynamic light scattering measurements showed that all mutant protein solutions contained a single molecule species, consistent with a trimeric oligomerization state. Analytical ultracentrifugation with wild-type TRAIL and M1 corroborated this finding (data not shown). In Vitro Bioactivity and Binding of Designed Mutants Bioactivity of the TRAIL mutants was assessed in vitro using the Colo205 human colon cancer cell line with a MTT based viability assay. A reduction in viability was measured using increasing concentrations of wild-type TRAIL or TRAIL mutants relative to the control. While M1, M3 and C1 showed a bioactivity comparable to that of wild-type TRAIL (ED50˜5 ng/ml), M2 exhibited bioactivity of nearly one order of magnitude lower (ED50˜50 ng/ml). Real-time binding of wild-type TRAIL and TRAIL mutants to the death receptors DR4 (TRAIL-R1) and DR5 (TRAIL-R2) was assessed using surface plasmon resonance with a Biacore 3000 instrument. Sensograms of M1, M3 and C1 were identical to that of wild-type TRAIL. In contrast, M2 whilst showing a similar level of binding to both receptors, displayed an increased off-rate when compared to the wild-type TRAIL sensogram (FIG. 2). Thermal Unfolding The thermal unfolding of wild-type TRAIL and TRAIL mutants was monitored by measuring changes in molar ellipticity at 222 nm upon heating. FIG. 3 shows the heat induced changes of wild-type TRAIL and TRAIL mutants. TRAIL shows an onset of unfolding at approximately 70° C. and has a transition midpoint of 77° C. The TRAIL mutants show however, onset of unfolding at increased temperatures and higher transition midpoints (FIG. 3). For M1 the onset of unfolding was at approximately 76° C. and the transition midpoint was at 85° C. M2 showed an onset of unfolding at approximately 74° C. M3 gave intermediate values between those of wild-type TRAIL and M1, with an onset of unfolding of 73° C. and a transition midpoint of 80° C. Mutant C1, representing the combined mutations of M1 and M3 showed values comparable to that of M1. The mutant belonging to the trimeric set (M4), however, showed an experimentally determined stability of approximately 3° C. less than wild-type TRAIL, and was therefore discontinued. The initial increase in molar ellipticity around 76° C. for M2 is due to an overall change of the far UV spectrum, reflecting a loss of structural properties of the starting material (data not shown). Upon cooling all protein solutions were turbid, indicating irreversible aggregation, therefore no thermodynamic parameters could be derived. Far and near UV wavelength CD scans at increasing temperatures confirmed the above findings (data not shown). Accelerated Thermal Stability Study In order to test the stability of TRAIL and TRAIL mutants over time, an accelerated thermal stability measurement was performed. The temperature of 73° C. was chosen to measure effects on stability within a 1 h timeframe. At this temperature wild-type TRAIL starts to unfold, while the mutants are still properly folded (FIG. 3). Protein solutions with the same concentration as used in the thermal unfolding measurements were incubated at 73° C. for 1 h and changes in molar ellipticity at 222 nm were measured (FIG. 4). The ellipticity of wild-type TRAIL decreased from the onset, giving a half-life of approximately 13 min. The signal for the M1, M2 and C1 mutants remained essentially constant, indicating an increased thermal stability. M3 showed a half-life of approximately 24 min. These measurements, however, are not indicative of the bioactive trimeric structure of the TRAIL molecule, but of the secondary structure of the monomeric unit. To monitor a concomitant increase in biological activity at elevated temperatures of the mutants with unchanged biological activity (M1, M3 and C1), protein solutions with the same concentrations as used in the thermal unfolding measurements were incubated at 73° C. and samples were taken at regular intervals for 1 h. Samples were subsequently diluted in tissue culture medium and added to Colo205 cells, resulting in a final concentration of 100 ng/ml. After overnight incubation the viability of the cells was measured using a MTT assay. Wild-type TRAIL showed decrease in bioactivity after 20 min of incubation, while M1 and C1 retained full bioactivity after incubation at 73° C. for 1 h (FIG. 5). M3 displayed an intermediate bioactivity between wild-type TRAIL and the other mutants. The increases in thermal stability of the mutants as measured with CD could therefore be correlated with a more stable biologically active trimeric molecule. Discussion Others have previously applied computational engineering techniques to improve thermal stability of alpha-helical proteins or monomeric beta-sheet molecules. However, frequently, monomeric proteins of less than 100 amino acids were used as targets. To our knowledge, this report is the first example of computational redesign of a large trimeric all-β-sheet protein towards a more thermal-stable variant. Significantly, it shows that the principles learned from design and engineering of small proteins can also be applied for large multimeric protein complexes. The wild-type TRAIL (114-281) molecule has a relatively high thermal stability if compared to some members of the TNF ligand family. Human tumor necrosis factor alpha (TNF-α), for example, has an apparent Tm of 65° C. as measured with circular dichroism (CD) (Narhi et al., Biochemistry 35, 11447-11453 (1996)) and the CD40L receptor binding domain has an apparent Tm of 60° C. as measured with differential scanning calorimetry (DSC) (Morris et al., J. Biol. Chem. 274, 418-423 (1999)). In parallel investigations, we can show using CD that RANKL however, is more thermal stable than TRAIL, with an apparent Tm of 5° C. higher than wild-type TRAIL, confirming another study (Willard et al., Protein Expr. Purif 20, 48-57 (2000)). In this study, we investigated the possibility of further increasing the thermal stability of TRAIL, as a model for all-β-sheet proteins, through the use of computational engineering. We succeeded in extending the apparent thermal stability of the β-sheet protein by more than 5° C. by using a combined approach, employing both TNF ligand family alignment information and an automated computational design algorithm. Due to the non-reversible nature of the unfolding reaction, the apparent Tm is not a perfect indication of an increase in stability. From a functional point of view, therefore, it also makes sense to study the time taken for the protein to denature at high temperature and to relate this to an effect on biological activity. The accelerated thermal stability study showed that the increase in thermal stability of the mutants as measured with CD spectroscopy (FIG. 4) can be correlated with the preservation of overall structural characteristics as highlighted by the lasting bioactivity of M1 during the experimental timeframe (FIG. 5). When measuring the residual bioactivity of wild-type TRAIL and TRAIL mutants upon incubation at 73° C. for 1 h, it was shown that, while wild-type TRAIL was all but thermally inactivated after ˜20 min, the mutants, significantly, had an improved stability with respect to wild-type TRAIL (FIG. 5). Thus measuring the stability of wild-type TRAIL and M1 at 73° C. is in this case indicative of an increased stability for M1 at more relevant temperatures, such as 37° C. or room temperature. Although not tested in this study, it has been shown that in case of certain therapeutically interesting proteins, improvement of thermal stability can also be indicative of an improved in vivo half-life (Luo et al., Protein Sci. 11, 1218-1226 (2002); Filikov et al., Protein Sci. 11, 1452-1461 (2002)). We are currently conducting studies to confirm this for our mutants. It is advantageous to use alignment information in order to focus the design on non-conserved residue positions. The reason for this is that conserved residues are usually retained in a family for a good reason and it is probable that any mutation will decrease protein stability (Serrano et al., J. Mol. Biol. 233, 305-312 (1993); Steipe et al., J. Mol. Biol. 240, 188-192 (1994)). On the other hand, regions with high sequence variability are tolerant to mutation and it can be expected that variants that stabilize the protein can be found in these regions (Serrano et al., J. Mol. Biol. 233, 305-312 (1993)). To accomplish our goal of redesigning a β-sheet protein, TRAIL, and to generate stable variants with the minimum number of mutations, the conserved residues forming the trimeric interface were therefore largely excluded from the prediction/optimization strategy. This resulted in an approach which focused mainly on improvement of the stability of the monomer (intra-chain stabilization; monomeric set) or improving monomer-monomer contacts (inter-chain stabilization; dimeric set). See Table 1. M1, M2, M3 and C1 showed, in agreement with our predictions, an increase in thermal stability (Table 2; FIG. 3-5). Different basic principles were used in the M1, M2 and M3 designs. M1 shows an example of intra-chain stabilization. Stabilization of the flexible CD loop at the surface of each TRAIL monomer results in an increased stability of the entire trimer. This loop is not directly involved in receptor binding and is disordered in un-complexed wild-type TRAIL structures (Cha et al., Immunity. 11, 253-261 (1999); Hymowitz et al., Biochemistry 39, 633-640 (2000)), but becomes ordered on binding to DR5 (TRAIL-R2) (Mongkolsapaya et al., Nat. Struct. Biol. 6, 1048-1053 (1999); Hymowitz et al., Mol. Cell 4, 563-571 (1999); Cha et al., J. Biol. Chem. 275, 31171-31177 (2000)). M2, however, illustrates the optimization of the interactions between two adjacent monomers, i.e. inter-chain stabilization. M4 displays the stabilization of the trimeric molecule by removing a buried unsatisfied hydrogen bond donor. Contrary to our expectations, the combination mutant, C1 (M1 and M3 combined) did not result in significant additive thermal stability. This might be due to the effects of local unfolding around residue 194 and 196, which could be more dominant than the effects of unfolding around residue 225. Although the predicted free energy change relative to wild-type TRAIL (−9.1 kcal mol−1 monomer−1) is favourable for M4, the experimentally determined stability was approximately 3° C. less than wild-type TRAIL. This is probably due to the fact that, the three central arginines, in addition to the hydrogen bonds formed with the backbone, trap water in the central core of the trimer. Water bridges are thus formed to compensate the positive charges and this results in further stabilization of the trimer. The mutation Arg 227 Met is presumably less stable since the backbone's carbonyl groups are uncompensated and destabilize the trimer. The increase in thermal stability did not affect the biological activity of M1, M3 and C1. M2 was more stable than wild-type TRAIL but the formation of an electrostatic interaction between Gln 205 and Arg 154 of the DR5 (TRAIL-R2) receptor was prevented (FIG. 6b). This resulted in a subsequent 10-fold decrease in biological activity (50 ng/ml) when compared to wild-type TRAIL (5 ng/ml), as predicted by FOLD-X (ΔΔGbinding=7.3 kcal mol−1 monomer−1). Our findings confirmed an earlier study showing decreased bioactivity of alanine mutants at these positions (Hymowitz et al., Biochemistry 39, 633-640 (2000)). Analysis of binding to the DR4 (TRAIL-R1) and DR5 (TRAIL-R2) receptors, using surface plasmon resonance, shows an increased off-rate for M2, indicating a lower affinity for both receptors, when compared to wild-type TRAIL and M1 (FIG. 2). Since ligand-receptor binding sites are normally “high energy regions”, the M2 mutations were expected to stabilize the TRAIL molecule. Thus, this could be regarded as an example of a possible increase in stability which is counterbalanced in evolution by loss of function. Frequently, other computational redesign studies limited the screening for improvement of thermal stability to the core of the molecule (Malakauskas & Mayo, Nat. Struct. Biol. 5, 470-475 (1998); Luo et al., Protein Sci. 11, 1218-1226 (2002); Filikov et al., Protein Sci. 11, 1452-1461 (2002)). Here we show that computational redesign techniques can also involve inter-chain interfaces and surface residues of the molecule, to successfully stabilize the structure. Performance of PERLA/FOLD-X was successful in the case of the intra-chain (monomer) set, the inter-chain (dimeric) set and the miscellaneous set. The experimental data corresponding to these designs showed all variants within these sets were more stable than wild-type TRAIL. Significantly, we could show that stabilization of the CD loop in a single monomer resulted in stabilization of the entire trimeric molecule (FIG. 6a). Our studies have shown that computer redesign of a more thermal stable multimeric all β-sheet protein is achievable. Computational protein redesign is therefore a valuable addition to other protein engineering methodologies, such as directed evolution or experimental high throughput approaches, as a tool for the improvement of protein properties. Since the computational method used in our study is based on general physical principles, our findings can be further applied to design other TNF ligand family members with improved thermal stability. Example 2 TRAIL Variants Selective for the DR4 (TRAIL-R1) or DR5 (TRAIL-R2) Receptor Methods All reagents were of analytical grade unless specified otherwise. Isopropyl-β-D-1-thiogalactoside (IPTG), ampicillin and dithiotreitol (DTT) were from Duchefa. Complete® protease inhibitor cocktail was purchased from Roche. Chromatographic columns and media were from Amersham Biosciences. Restriction enzymes used were purchased from New England Biolabs. All other chemicals were from Sigma. Computational Design of Mutants Computational design using the protein design algorithm, PERLA and FOLD-X has been described above. Similarly, the resultant PDB files containing the mutations were energy minimized using GROMOS 43B1 as implemented in Swiss-PdbViewer v3.7b2, and evaluated by FOLD-X (http://fold-x.embl-heidelberg.de). The final energies of interaction from the designs of TRAIL mutants interacting with its different receptors are compared to the reference, wild-type TRAIL in complex with its four membrane receptors and expressed as ΔΔG (kcal mol−1). Computer Screening Novel mutants of TRAIL have been designed in order to shift selectivity/specificity towards its different membrane receptors (DR4(TRAIL-R1), DR5(TRAIL-R2), DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4)). These receptors are described by Pan et al., Science. 1997 Apr. 4; 276(5309):111-3 (DR4); Screaton et al., Curr Biol. 1997 Sep. 1; 7(9):693-6 (DR5); Degli-Esposti et al., J Exp Med. 1997 Oct. 6; 186(7):1165-70 (DcR1 (TRAIL-R3)) and Marsters et al., Curr Biol. 1997 Dec. 1; 7(12):1003-6 (DcR2 (TRAIL-R4)). Designs were based on the automated computer algorithm, PERLA, as described above. Briefly, this algorithm performs strict inverse folding: a fixed backbone structure is decorated with amino acid side chains from a rotamer library. Relaxation of strain in the protein structure is achieved via the generation of subrotamers. Most terms of the scoring function are balanced with respect to a reference state, to simulate the denatured protein. The side chain conformers are all weighted using the mean-field theory and finally candidate sequences with modelled structures (PDB coordinates) are produced. Energy evaluation of the modelled structures was carried-out by a modified version (Schymkowitz, J., Borg, J., Rousseau, F. & Serrano, L, “manuscript in preparation”) of FOLD-X, (available at http://fold-x.embl-heidelberg.de). The force field module of FOLD-X evaluates the properties of the structure, such as its atomic contact map, the accessibility of its atoms and residues, the backbone dihedral angles, in addition to the H-bond network and electrostatic network of the protein. The contribution of water molecules making two or more H-bonds with the protein is also taken into account. FOLD-X then proceeds to calculate all force field components: polar and hydrophobic solvation energies, van der Waals' interactions, van der Waals' clashes, H-bond energies, electrostatics, and backbone and side chain entropies. Selection of the Template Sequence Template was selected from the Protein Data Bank, PDB identifier 1DU3. This is the crystal structure at 2.2 Å resolution of the trimeric structure of human TRAIL in complex with the ectodomain of the DR5 (TRAIL-R2) receptor. In this structure TRAIL monomers lack an external, flexible loop (residues 130-146), not involved in receptor binding. To complete this template, this loop was modelled using the crystal structure of 1D4V (2.2 Å), a monomeric TRAIL in complex with DR5 (TRAIL-R2) receptor, which has the atomic coordinates of this loop. Modeling TRAIL Non-crystallized Receptors Models of the three other TRAIL membrane receptors (DR4 (TRAIL-R1), DcR1 (TRAIL-R3) and DcR2 (TRAIL-R4)) were obtained using “What If Homology Modeling web interface” (available at http://www.cmbi.kun.nl/gv/servers/WIWWWI/). Afterwards, pdb files of TRAIL in complex with these three receptors were generated by imposing their backbone atoms over the same atoms of the receptor DR5 (TRAIL-R2), using Swiss-PdbViewer v3.7b2. Finally, template receptor DR5 (TRAIL-R2) was removed from the generated PDB file. Modeling Interactions Between TRAIL and Modelled Receptors Rational design of the occurring interactions between TRAIL and the three modelled receptors was carried out in the following way: First, receptors' binding interface with TRAIL were studied looking for target amino acids for rotamer replacement. Selected side chains were the ones physically close enough to TRAIL to be potentially interacting with it. Conserved residues with receptor DR5 (TRAIL-R2) were discarded from this rotamer replacement. Second, PERLA performed a rotamer search looking for better side chains conformations, aiming to model the expected interactions of TRAIL with these receptors. Finally, an overall visual inspection of the binding interface of TRAIL with the different receptors was carried out and some rotamers were changed. Computational Design of Mutants Only TRAIL amino acids located in the receptor-binding interface were considered as potential candidates for in silico mutagenesis. Residues interacting either with conserved amino acids among the four different receptors or with receptor backbone were discarded from this list. The use of protein rational design and force field algorithms (PERLA, FOLD-X) allowed the identification of a list of mutant sequences with potential relevance for TRAIL selectivity/specificity. The automated computer algorithm PERLA was applied as previously described. All possible amino acid substitutions (with the exception of Glycine, Proline, and Cysteine) were introduced at the previously selected residue positions in conformations (side chain rotamers) compatible with the rest of the structure. Subsequently, favourable mutations were evaluated in terms of free energy (kcal mol-1), and unfavourable mutations (e.g. high Van der Waals' clashes) were eliminated. An output of sequences and coordinates was obtained and ranked in terms of free energy using FOLD-X. Some of these predictions were discarded directly after theoretical energy calculations, without further experimental analysis. Cloning and PCR cDNA corresponding to human soluble TRAIL (aa 114-281) was cloned in pET15B (Novagen) using NcoI and BamHI restriction sites. The N-terminal sequence encoding a His-tag and protease recognition site was therefore removed. Mutants were constructed by PCR using the Quick Change Method (Stratagene) or a modified megaprimer method. The polymerase used was Pfu Turbo supplied by Stratagene. Purified mutagenic oligonucleotides were obtained from Invitrogen. Introduction of mutations was confirmed by DNA sequencing. Screening for Selectivity Mutants TRAIL mutant constructs were transformed to Escherichia Coli BL21 (DE3) (Invitrogen). Mutants and wild-type TRAIL were grown at a 10 ml scale, using a 2×LB medium. Cultures were grown to OD600 0.5 at 37° C. and 250 rpm, and protein expression was subsequently induced with 1 mM IPTG. ZnSO4 was added at a concentration of 100 μM to promote trimer formation. Temperature was lowered to 28° C. and induction was continued for 5 h. Cells were harvested by centrifugation. Pellet was resuspended in extraction buffer (PBS pH 7.3, 10% (v/v) glycerol and Complete® protease inhibitor cocktail), in 25% of the original volume. Cells were disrupted using sonication and extracts were clarified by centrifugation at 20,000 g. TRAIL mutant protein expression was assessed using SDS-PAGE. Clarified extracts of mutants that were well expressed, were subsequently diluted 1:50 in HBS-EP buffer. These dilutions of the wild-type TRAIL and TRAIL mutants were injected in two-fold, at a flow rate of 50 μl/min on a Biacore 2000. A Biacore CM5 sensor chip coated with the TRAIL receptors DR4 (TRAIL-R1), DR5 (TRAIL-R2) and DcR1 (TRAIL-R3) and with RANK (receptor) as control surface, was used. Binding of ligands to the receptors was monitored in real-time. The receptor/sensor surface was regenerated using 3 M sodium acetate pH 5.2 injections. Ratios of binding for the different receptors were calculated relative to DR4 (TRAIL-R1) or DR5 (TRAIL-R2) binding, respectively. Mutants having different binding profiles compared to the binding profiles of wild-type TRAIL were chosen for subsequent analysis. Expression and Purification of Wild-type TRAIL and Mutants The chosen mutants were grown in shake flasks at a 1 l scale at 250 rpm and 37° C., using a 2×LB medium. Protein expression was induced with 1 mM IPTG when the culture reached OD600 0.5, ZnSO4 was added at a concentration of 100 μM. Temperature was lowered to 28° C. and induction was continued for 5 h. The isolated pellet was resuspended in 3 volumes extraction buffer (PBS pH 8, 10% (v/v) glycerol, 7 mM β-mercapto-ethanol). Cells were disrupted using sonication and extracts were clarified by centrifugation at 40,000 g. Subsequently, the supernatant was loaded on a nickel charged IMAC Sepharose fast-flow column and wild-type TRAIL and TRAIL mutants were purified as described by Hymowitz (see above) with the following modifications: 10% (v/v) glycerol and a minimal concentration of 100 mM NaCl were used in all buffers. This prevented aggregation during purification. After the IMAC fractionation step, 20 μM ZnSO4 and 5 mM of DTT (instead of β-mercapto-ethanol) was added in all buffers. Finally, a gelfiltration step, using a Hiload Superdex 75 column, was included. Purified proteins were more than 98% pure as determined using a colloidal coomasie brilliant blue stained SDS-PAGE gel. Purified protein solutions were flash frozen in liquid nitrogen and stored at −80° C. Screening for Selectivity Mutants Extracts of 16 expressing mutants were evaluated for binding to DR4 (TRAIL-R1), DR5 (TRAIL-R2) and DcR1 (TRAIL-R3) receptors using surface plasmon resonance with a Biacore 3000 instrument. Binding to murine RANK (receptor) was monitored as control as wild-type TRAIL does not bind to this receptor. Control extracts of BL21 (DE3) culture without an over-expression plasmid and of a BL21 (DE3) culture with plasmid over-expressing SH3 domain were also injected. No binding was observed for these extracts. The ratio of DR4 (TRAIL-R1), DcR1 (TRAIL-R3) or RANK (receptor) binding with respect to DR5 (TRAIL-R2) receptor binding (FIG. 7) and of DR5 (TRAIL-R2), DcR1 (TRAIL-R3) or RANK (receptor) binding with respect to DR4 (TRAIL-R1) receptor binding (FIG. 8), were calculated. The ratios values obtained for TRAIL selectivity mutants binding were compared to the ratios obtained for wild-type TRAIL binding. Receptor binding curves were also visually inspected for alterations in on and off rates when compared to the on and off rates of wild-type TRAIL. Two mutants, D269H and G160M, with a reduced binding to the DR4 (TRAIL-R1) and unchanged binding to the DR5 (TRAIL-R2) receptor (“selective” for DR5 (TRAIL-R2)) were chosen for further analysis. We have shown an increased off-rate of D269H w.r.t. DR4 but this does not imply that we have seen an increased binding for DR5. Our current data does imply that we have directed the binding of this mutant towards DR5 binding, hence it is more selective/specific for the DR5 receptor. Affinity can of course be improved after selectivity variants are chosen. I220M and E195R (not shown) were also elected, as they also showed a reduced binding to the DR4 (TRAIL-R1) and increased binding to the DR5 (TRAIL-R2) receptor. The effects, however, were smaller than that of the previous two mutants. D218Y was chosen for further analysis, as it showed a small preference for binding to the DR4 (TRAIL-R1) receptor, compared to wild-type TRAIL. R130E was chosen as it showed a small reduction in binding to the DcR1 (TRAIL-R3) receptor (less “selective” for DcR1 (TRAIL-R3)). Determination of Receptor Binding Mutants R130E, G160M, D218Y, (I220M and D269H were purified. Binding of the purified mutants was assessed in real time using surface plasmon resonance on a Biacore 3000 with a sensor chip as described above. Mutants and purified wild-type TRAIL were injected in a concentration series of 17.3, 34.5, 69, 138 and 276 mM at a flow rate of 70 μl/min. Measurements performed at 37° C. to allow increased koff and dissociation was monitored for 20 min. Measured kon and koff rates were used to calculate apparent Kd values for the mutants for the respective receptors. A global fit procedure was used and a 1:1 Langmuir interaction model. A biphasic behavior was found for the kon and koff. The preliminary apparent Kd values were calculated and are shown in table 3. In vitro studies of the TRAIL mutants D269H Experimental Conditions Cell line and treatment: Colo205 colon cancer cells were maintained in RPMI1640 medium, 10% FCS, 1% penicillin, 1% streptomycin in humified incubator, 37° C., in 5% CO2 environment. TRAIL receptor inhibitors (neutralising antibodies) were always added 1 h before TRAIL addition. The Colo205 cells were seeded the day before the experiment at 105 cells/ml in 24 well plates, 1 ml/well were treated with increasing concentration of antiDR4 and anti DR5 neutralising antibodies for 1 h. 20 ng/ml D269H was added to the cells and incubated for 2 h and 30 minutes. After treatment, the cells were harvested by scraping them gently off the wells and spun down. Annexin V Staining: Control or treated Colo205 cells were harvested and collected by centrifugation, washed once in Annexin V incubation buffer and resuspended in 400 μl fresh incubation buffer. 1 μl Annexin V was added to the samples, incubated at room temperature for 10 minutes and measured immediately on a FACSCalibur Flow cytometer (Beckton Dickinson), results being expressed as % of annexin V positive cells. Caspase assay: Colo205 cells were plated in 6 well plates at 200,000 cells/ml, 3 ml/well on the day before the experiment. R2C16 (100 ng/ml and 500 ng/ml), antiDR4 (TRAIL-R1) and antiDR5 (TRAIL-R2) neutralizing antibodies (Alexis) (200 ng/ml) were added into the culture medium 1 h before adding TRAIL (10 ng/ml). Cells were harvested for caspase activity assay after 2 h treatment with TRAIL. Cells were pelleted, washed twice in ice cold PBS, resuspended in 50 ml PBS, 2×25 ml cell suspension was snap frozen. Caspase enzyme activity was measured using fluorescently tagged DEVD-MCA (for caspase-3 and -7-like activity), or IETD-MCA (for caspase-8) tetrapeptides. The fluorescence intensity caused by the released MCA was measured kinetically in 25 cycles with 60 sec intervals. The enzyme activity was calculated as nmole MCA released per minute by 1 mg total protein. MTT assay: Colo205 cells were seeded in 96 well plates at 200,000 cells/ml, 100 μl/well. Each treatment was carried out in triplicates. After 24 h treatment 500 μg/ml MTT stain was added to the wells and was incubated at 37° C. for 3 h. The reaction was stopped and the formazan precipitate was dissolved by adding 100 μl 20% SDS in 50% dimethylformamide. Results For the analysis of the apoptosis inducing potential of D269H TRAIL sensitive Colo205 colon carcinoma cells were treated with increasing concentrations of TRAIL (aa 114-281) or D269H for 2 and 3 hours. Annexin V labelling of the apoptotic cells was used to monitor the level of cell death induced. Our results (see FIGS. 9, 10 and 11) revealed that the two ligands have comparable death inducing potential in Colo205 cells. Thus, the designed mutations in D269H did not decrease its cytotoxic potential significantly (FIG. 12). In order to examine which TRAIL receptor is more involved in D269H induced death, 1 hour prior to D269H treatment of Colo205 cells, increasing amounts of neutralizing antiDR4 or antiDR5 antibodies were administered. The presence of the antiDR4 antibody failed to prevent death induced by D269H. On the other hand, already the lowest concentration (200 ng/ml) of antiDR5 antibody almost completely prevented cell death (FIG. 13). These results suggest that D269H induces cell death primarily through ligation of TRAIL receptor 2 (DR5). Similar studies on different cell lines will be required to prove that this effect is not cell type specific and these are on-going. Example 3 Receptor Specific TRAIL Variants: Binding Analysis by SPR Binding experiments were performed using a surface plasmon resonance-based biosensor Biacore 3000 (Biacore AB, Uppsala, Sweden), at 37° C. Recombinant receptors were ordered from R&D systems (R&D systems, Minneapolis, Minn., USA). Immobilization of the DR4, DR5 and RANK receptors on the sensor surface of a Biacore CM5 sensor chip was performed following a standard amine coupling procedure according to the manufacturer's instructions. Receptors were coated at a level of ˜600-800 RU. Purified wild-type TRAIL and TRAIL mutants were injected in three-fold at concentrations ranging from 250 nM to 0.1 nM at 70 μl/min flow rate and at 37° C. Between injections the receptor/sensor surface was regenerated using 30 μl of 3 M sodium acetate pH 5.2. Mutants R130E, G160M, D218Y, I220M, D269H, D269K, D269R, D269HT214R, D269HE195R and R191ED267R were purified as described in Example 2. Binding of the purified mutants to immobilized TRAIL-R1, TRAIL-R2 and TRAIL-R3 Fc receptor was assessed in real time using surface plasmon resonance. Mutants and purified wild-type TRAIL were initially analyzed at a concentration of 60 μM (FIG. 14). Binding curves of variants showing a significant change in the ratio TRAIL-R1(DR4)/TRAIL-R2(DR5) binding were subsequently recorded for concentrations ranging from 0.1 to 250 nM. All variants comprising a D269H/R/K substitution were found to be TRAIL-R2 Fc selective. Variants D269H/R/K and D269HE195R showed >10 fold improvement in binding to TRAIL-R2 Fc and >15 fold reduction in binding to TRAIL-R1 Fc relative to wild-type TRAIL (FIG. 15 a,b,c&d). The D269HT214R variant had a comparable improvement as the D269H single mutant in TRAIL-R2 Fc binding, however no detectable binding to TRAIL-R1 Fc was found (FIG. 15 a&c). Variant R191ED267R was also found to be selective for TRAIL-R2; it showed decreased binding to TRAIL-R2 Fc but complete abolishment of binding to TRAIL-R1 Fc (FIG. 16 a&b). Binding of D269H towards the decoy TRAIL-R3 Fc receptor was ˜10 fold decreased when compared to wild-type TRAIL (FIG. 18a). Mutation D218Y was designed to result in a DR4 (TRAIL-R1) specific TRAIL variant. Whereas wild-type TRAIL has a higher affinity for DR5 than DR4 this preference is lost in the mutant (FIG. 16c). Example 4 TRAIL Variants Selective for DR5: Competition ELISA To assess the selectivity of the TRAIL-R2 (DR5) selective mutants towards the TRAIL-R2 receptor in the presence of another TRAIL receptor a competition ELISA experiment was performed. Nunc Maxisorb plates were coated during 2 hr with TRAIL-R2-Fc (100 ng/well) in 0.1 M Sodium Carbonate/Bicarbonate buffer pH 8.6 and remaining binding places were subsequently blocked with 2% BSA for 1 hr. After 6 times washing with TBST (TBS-0.5% Tween-20 pH 7.5), pre-incubated (30 min) serial dilutions of soluble TRAIL-R1 (DR4), TRAIL-R2(DR5) or TRAIL-R3 Fc (0-500 ng/well) and 10 ng/well purified rTRAIL or mutants (purified as described in example 2) were added to the wells and incubated for 1 hr at RT. After 6× washing with TBST a 1:200 dilution of anti-TRAIL antibody (R&D systems) was added and incubated for 1 hr at RT and after 6× washing with TBST, subsequently, incubated with a 1:25000 dilution of a horse radish peroxidase conjugated swine-anti goat antibody. After 6× washing with TBST 100 μl of 1-step Turbo TMB solution (Pierce) was added and after ˜15 min the reaction was quenched with 100 μl 1 M sulfuric acid. The absorbance was measured at 450 nM on a microplate reader (Thermolab systems). Binding of wild-type TRAIL or mutants to immobilized TRAIL-R2 Fc with 0 ng/well of the soluble receptors was taken as 100% and binding at other concentrations of soluble receptors was calculated relative to 0 ng/well of soluble receptor. Increasing concentrations of soluble TRAIL-R1 Fc or TRAIL-R2 Fc were both capable of competing with immobilized TRAIL-R2 Fc for wild-type TRAIL binding. In contrast, soluble TRAIL-R1 Fc was unable to compete with immobilized TRAIL-R2 Fc for binding with the TRAIL-R2 selective variants (FIG. 17 a,b,c&d). However, soluble TRAIL-R2 Fc was able to compete for binding with the immobilized TRAIL-R2 Fc. Pre-incubation with increasing concentrations of TRAIL-R3 Fc did not affect the binding of the TRAIL-R2 selective variants to immobilized TRAIL-R2 Fc. Wild-type TRAIL showed, in contrast, a 10-15% decrease in binding to immobilized TRAIL-R2 when pre-incubated with the highest concentration of TRAIL-R3 Fc (FIG. 18b). The difference in level of competition of wild-type TRAIL binding between TRAIL-R3 Fc and TRAIL-R2 Fc is caused by >100 fold difference in affinity of wild-type TRAIL for the two receptors, respectively 200 nM and <2 nM (Truneh et al., J. Biol. Chem. 275, 23319-23325 (2000)). Example 5 Additional In Vitro Studies of DR5-selective Mutants To assess the biological activity of the DR5 (TRAIL-R2) selective mutants an Annexin V based apoptosis assay was performed using a cell-line sensitive for DR5-receptor mediated induction of apoptosis (Colo205) and a cell-line sensitive for DR4 mediated induction of apoptosis (ML-1). Cell line and treatment: Colo205 colon cancer cells and ML-1 myeloid leukaemia cells were maintained in RPMI1640 medium, 10% FCS, 1% penicillin, 1% streptomycin in humidified incubator, 37° C., in 5% CO2 environment. TRAIL receptor inhibitors (neutralising antibodies) were always added 1 h before TRAIL addition. Cells were seeded the day before the experiment at 2×105 cells/ml in 24 well plates (0.5 ml/well). Colo205 cells were treated with 1 μg/ml of anti-DR4 and/or anti-DR5 neutralising antibodies for 1 h. 20 ng/ml wild-type TRAIL, D269H, D269HE195R or 50 ng/ml D269HT214R was added to the cells and incubated for 2 h and 30 minutes. ML-1 cells were treated with 1 μg/ml of anti-DR4 and/or anti-DR5 neutralising antibodies for 1 h prior to TRAIL treatment. 100 ng/ml wild-type TRAIL, D269H, D269HE195R or D269HT214R was added to the cells and incubated for 12 h. Annexin V Staining: Control or treated Colo205 cells and ML-1 cells were harvested and collected by centrifugation, washed once in Annexin V incubation buffer and resuspended in 400 μl fresh incubation buffer. 3 μl Annexin V (IQ Corporation) was added to the samples, incubated at room temperature for 10 minutes and measured immediately on a FACSCalibur Flow cytometer (Beckton Dickinson), results being expressed as % of Annexin V positive cells. MTT assay: Colo205 cells were seeded in 96 well plates at 2×105 cells/ml (100 μl/well). Each treatment was carried out in triplicates. After 24 h treatment 500 μg/ml MTT stain was added to the wells and was incubated at 37° C. for 3 h. The reaction was stopped and the formazan precipitate was dissolved by adding 100 μl 20% SDS in 50% dimethylformamide. Results The MTT assay showed that wild-type TRAIL and D269H, D269HE195R and D269HT214R (purified as described in examples 1 and 2) were biologically active and able to induce cell death in Colo205 cells (data not shown). For the analysis of the specific apoptosis inducing potential of wild-type TRAIL, D269H, D269HE195R and D269HT214R, TRAIL sensitive Colo205 colon carcinoma cells were treated with 20 ng/ml purified wild-type TRAIL or D269H, D269HE195R or D269HT214R for 2.5 hours. Annexin V labelling of the apoptotic cells was used to monitor the level of cell death induced. Our results revealed that the ligands have comparable death inducing potential in Colo205 cells as wild-type TRAIL. Thus, the designed mutations in D269H, D269HE195R and D269HT214R did not decrease its cytotoxic potential significantly. In order to examine which TRAIL receptor is more involved in wild-type, D269H, D269HE195R or D269HT214R induced cell-death, 1 hour prior to wild-type or mutant treatment of Colo205 cells, 1 μg/ml of neutralizing anti-DR4 or anti-DR5 antibodies were administered. The presence of the anti-DR4 antibody failed to prevent death induced by D269H, D269HE195R or D269HT214R. On the other hand 1 μg/ml of antiDR5 antibody could significantly reduce the amount cell death. In contrast, both anti-DR4 and anti-DR5 antibodies are able to significantly reduce the amount of cell death induced by wild-type TRAIL in Colo205 cells. These results suggest that D269H, D269HE195R and D269HT214R induce cell death primarily through ligation of TRAIL receptor 2 (DR5). TRAIL receptor induced apoptosis in ML-1 myeloma cells was found to be mainly mediated by the DR4 (TRAIL-R1) receptor. Only anti-DR4 antibody could significantly reduce wild-type TRAIL mediated cell-death in these cells. Addition of anti-DR5 did not have a significant effect on wild-type TRAIL mediated cell-death. Mutants D269H, D269HE195R and D269HT214R were unable to induce a comparable level of apoptosis as wild-type TRAIL in this cell line. These results suggest that D269H, D269HE195R and D269HT214R are unable to induce cell death through ligation of DR4 (TRAIL-R1). Taken together, the results obtained with the Colo205 and ML-1 cell lines show that the biological activity of the D269H, D269HE195R and D269HT214R mutants is mainly directed towards the DR5 (TRAIL-R2) receptor. Example 6 Second Round of Design Using in vitro and in vivo results obtained from the 1st generation of receptor selective TRAIL mutants DR4 receptor homology models were improved and additional amino acid residue positions in TRAIL were screened for receptor selectivity using methodology as described in Example 2 in order to obtain mutants with improved receptor selective properties. FIG. 20 A depicts the residues used in 1st and 2nd round in silico mutagenesis using PERLA/FOLD-X (highlighted with Van der Waals radius.) Mutant D269H designed in the 1st round was found to be a critical for DR5 selectivity. Additional, a 2nd round of in silico mutagenesis of the Aspartate at position 269 was performed. From this second round D269K and D269R, in addition to D269H, are predicted to shift receptor selectivity towards DR5 (TRAIL-R2) (FIG. 20 B). (A negative ΔΔG value is indicative of improved binding and a positive ΔΔG of decreased receptor binding.) From the crystal structure of TRAIL in complex with DR5 (TRAIL-R2), residue 269 seems not to have any direct interaction with the DR5 receptor, however, the substitution of this residue with Lysine, Histidine or Arginine worsens dramatically the binding with all the receptors but DR5. This can be explained due to the presence of a conserved Lysine in position 120 on the receptors DR4, DcR1, DcR2. This lysine, according to our models, is not making any interaction with TRAIL, but is close enough to the receptor interface to have a Van Der Waals clash, or at least, repulsive electrostatic interaction, with the amino acid substitutions in position 269 of TRAIL here described. This design data correlates with experimental receptor binding studies and competition ELISAs (see also Examples 3 and 4). Residue 218 was predicted to be important for shifting selectivity to towards DR4 (TRAIL-R1). Mutant D218Y designed in the 1st round confirmed this shift towards DR4 selectivity. Additionally, a 2nd round of in silico mutagenesis of the Aspartate at position 218 was performed. From this second round D218K, D218R and especially D218H, in addition to D218Y, are predicted to shift receptor selectivity towards DR4 (TRAIL-R2) (FIG. 20 C). (A negative ΔΔG value is indicative of improved binding and a positive ΔΔG of decreased receptor binding.) Residue position 214 and DR5 selectivity. The substitution of TRAIL threonine in position 214 by an arginine, was predicted to shift selectivity towards DR5 (FIG. 20 d). This mutation in combination with the already tested mutation D269H was tested in order to reach a cleaner selectivity. This was experimentally confirmed. D269HT214R showed improved binding towards DR5 (TRAIL-R2) and complete abolishment of DR4 (TRAIL-R1) binding (Examples 3 and 4). Combination of mutants at positions 214 and 269 for selectivity towards DR5. We have already shown experimental characterization of the mutants D269H, D269K, D269R and T214R-D269H. The additive effect of mutations towards selectivity can be expected, at least presumably, in the cases where the positions of the mutations are far away enough from each other so they cannot make any non-predictable interaction between each other. This is the case of positions 214 and 269, which are around 20 Å away from each other. Therefore, with the data from the mutants D269H and T214R-D269H, we can expect that both mutations contribute to selectivity in an independent way, so we consider the mutant T214R as selective towards DR5. The presumable structural basis of position 269 selectivity has been already explained before. The fact that the three different substitutions in position 269 give a more or less similar shift in selectivity could possibly mean that this selectivity is reached due to a clash and/or electrostatic repulsion that depends on the amino acid size and/or charge. Therefore, after observing the results of the mutant T214R-D269H, we can presume that the combinations of T214R with either D269R or D269K will have a similar effect on selectivity. PERLA/FOLDX calculations indicate that these mutations have indeed a similar effect. Example 7 Combination of Stability and Selectivity Mutants Combinations between the stability variants and selectivity variants described above can be made, giving variants with enhanced stability and altered selectivity/specificity. Combinations between the TRAIL M1 and C1 mutants (stability mutants), combined with one or more of the D269H, D269HE195R, D269HT214R, D269K, D269R and R191ED267R mutants (selectivity mutants) were constructed and purified as described in Examples 1 and 2. Mutants were tested for receptor binding and biological activity as described in Examples 1, 2 and 3. A comparison between wild-type TRAIL and D269HM1 is given as an example. Binding of the purified wild-type TRAIL and D269HM1 to immobilized TRAIL-R1 and TRAIL-R2 Fc receptor was assessed in real time using surface plasmon resonance. Binding curves were recorded for concentrations ranging from 0.1 to 250 nM. Variant D269HM1 showed >8 fold improvement in binding to TRAIL-R2 Fc and >8 fold reduction in binding to TRAIL-R1 Fc relative to wild-type TRAIL (FIG. 21 a&b). To monitor a increase in biological activity at elevated temperatures of the mutants, protein solutions with a concentration of 100 μg/ml were incubated at 73° C. and samples were taken at regular intervals for 1 h. Samples were subsequently diluted in tissue culture medium and added to Colo205 cells, resulting in a final concentration of 100 ng/ml. After overnight incubation the viability of the cells was measured using a MTT assay. Wild-type TRAIL showed a noticeable decrease in bioactivity after only 10 min of incubation, while D269HM1 retained full bioactivity after incubation at 73° C. for 50 min (FIG. 21 c). TABLE 1 Residues initially considered for design Monomer Set Dimer Set Trimer Set Misc. Set E194† H125 R227† A123 I196† F163 C230 A272 Y185 Y240 S225† Q187 V280 S232 F163 D234 A123 Y237† (D203, Q205) V208 L239 S241 E271† F274 †Used in subsequent rounds of design Mutants in parenthesis were added in subsequent rounds as interaction partners TABLE 2 Computational design results ΔΔGstability* ΔΔGbinding*‡ Set Mutations M1 −9.7 0.4 Monomer E194I, I196S M2 −4.0 7.3 Dimer D203I, Q205M, Y237F M3 −7.0 −0.5 Misc. S225A M4 −9.1 −1.2 Trimer R227M C1 −11.4 −0.9 Combination M1 + M3 *Energy in kcal mol−1, calculated per monomer ‡ΔGbinding = ΔGcomplex − (ΣΔGchain); ΔΔGbinding = ΔGbinding mutant − ΔGbinding wild-type TABLE 3 Apparent Kd values for DR4 (TRAIL-R1) and DR5 (TRAIL-R2) receptors DR4(TRAIL-R1) DR5(TRAIL-R2) (nM) (nM) Wt TRAIL 0.6 0.4 G160M 0.4 0.5 D269H 0.6 <0.4 D218Y ? ? others N.D. N.D. TABLE 4 Critical residues identified for receptor binding without distinction between DR4 and DR5. Mutant Effect on DR4 binding Effect on DR5 binding I220H Highly decreases Highly decreases I220M Highly decreases Highly decreases R149D Decreases Decreases R149H No observable effect No observable effect E155M Highly decreases Highly decreases G160K Highly decreases Highly decreases G160M Highly decreases Highly decreases D218F Decreases Decreases D218Y Decreases Decreases D218R No observable effect No observable effect TABLE 5 Critical residues identified for selectivity. Mutant Effect on DR4 binding Effect on DR5 binding R130E Decreases Slightly decreases G131R Decreases Slightly decreases D269H Highly decreases No observable effect TABLE 6 The TNF ligand-receptor family and association with autoimmune disease Disease showing Ligands Receptors Function association APRIL TACI, BCMA and unknown Probably co-stimulator of B RA, SLE and T cells 4-1BBL (TNFSF9) 4-1BB (TNFSFR9) T-cell costimulator/regulator EAE, RA BAFF (TNFSF13B/20)* TACI, BCMA, BAFF-R B cell survival/maturation, SLE, SS, RA T cell costimulation CD30L (TNFSF8) CD30 (TNFSFR8) Modulator of T cell function SLE, RA, SS, autoimmune thyroid disease, primary biliary cirrhosis CD40L (TNFSF5)* CD40(TNFSFR5) B cell survival, stimulation SLE, SS, IBD, EAE and differentiation FasL (TNFSF6) Fas(TNFSFR6). DcR3 Apoptosis SLE, EAE, diabetes. autoimmune thyroid disease and autoimmune hepatitis GITRL (TNFSF18) GITR(TNFSFR18) T-cell costimulator/regulator unclear LIGHT (TNFSF14) LTβ-R, HVEM, DcR3 T-cell activation and Diabetes, possibly RA (TNFSFR6B) thymocyte survival LTα (TNFSF1) human TNF-R1, TNF-R2, HVEM Inflammation RA, SLE, IBD, MS, diabetes (TNFSFR3) LTα/β LTβ-R, HVEM, DcR3 Thl responses, lymph node RA, SLE, IBD, MS, diabetes (TNFSFR6B) development, splenic architecture and organization OX40L (TNFSF4) OX40 (TNFSFR4) T-cell costimulator EAE, RA, IBD RANKL (TNFSF11)* RANK (TNFSFR11A), Dendritic cell survival, RA OPG osteoclast formation TNF (TNFSF2)* TNF-R1(TNFSFR1A), TNF- Inflammation, splenic RA, SLE, IBD, MS, diabetes R2 (TNFSFR1B) organization TRAIL (TNFSF10)* TRAIL-R1 (DR4, Induces tumour cell death Favorable in RA model TNFSFR10A), TRAIL-R2 Blocks T cell proliferation Possible autoimmune (DR5, TNFSFR10B), thyroid disease; Possibly TRAIL-R3 (DcR1, MS. TNFSFR10C), TRAIL-R4 (DcR3, TNFSFR10D), OPG (TNFSFR11B) TWEAK TWEAK-R may contribute to Brain inflammation; macrophage homeostasis by angiogenesis. mediating CD4 (+)T-cell killing of antigen-presenting macrophages; Induces proliferation in endothelial cells. TWEPRIL Possibly TACI, BCMA and Requires further elucidation Requires further elucidation unknown MS, multiple sclerosis; RA, rheumatoid arthritis; SLE, systemic lupus erythe matosus; SS, Sjorgen's syndrome; EAE, experimental autoimmune encephalomyelitis; IBD, inflammatory bowel disease. Trail Specific Sequences SEQ ID NO: 1 (TRAIL AMINO ACID SEQUENCE) MAMMEVQGGPSLGQTCVLIVIFTVLLQSLCVAVTYVYFTNELKQMQDKYS KSGIACFLKEDDSYWDPNDEESMNSPCWQVKWQLRQLVRKMILRTSEETI STVQEKQQNISPLVRERGPQRVAAHITGTRGRSNTLSSPNSKNEKALGRK INSWESSRSGHSFLSNLHLRNGELVIHEKGFYYIYSQTYFRFQEEIKENT KNDKQMVQYIYKYTSYPDPILLMKSARNSCWSKDAEYGLYSIYQGGIFEL KENDRIFVSVTNEHLIDMDHEASFFGAFLVG SEQ ID NO:2 (TRAIL NUCLEOTIDE SEQUENCE) CCTCACTGACTATAAAAGAATAGAGAAGGAAGGGCTTCAGTGACCGGCTG CCTGGCTGACTTACAGCAGTCAGACTCTGACAGGATCATGGCTATGATGG AGGTCCAGGGGGGACCCAGCCTGGGACAGACCTGCGTGCTGATCGTGATC TTCACAGTGCTCCTGCAGTCTCTCTGTGTGGCTGTAACTTACGTGTACTT TACCAACGAGCTGAAGCAGATGCAGGACAAGTACTCCAAAAGTGGCATTG CTTGTTTCTTAAAAGAAGATGACAGTTATTGGGACCCCAATGACGAAGAG AGTATGAACAGCCCCTGCTGGCAAGTCAAGTGGCAACTCCGTCAGCTCGT TAGAAAGATGATTTTGAGAACCTCTGAGGAAACCATTTCTACAGTTCAAG AAAAGCAACAAAATATTTCTCCCCTAGTGAGAGAAAGAGGTCCTCAGAGA GTAGCAGCTCACATAACTGGGACCAGAGGAAGAAGCAACACATTGTCTTC TCCAAACTCCAAGAATGAAAAGGCTCTGGGCCGCAAAATAAACTCCTGGG AATCATCAAGGAGTGGGCATTCATTCCTGAGCAACTTGCACTTGAGGAAT GGTGAACTGGTCATCCATGAAAAAGGGTTTTACTACATCTATTCCCAAAC ATACTTTCGATTTCAGGAGGAAATAAAAGAAAACACAAAGAACGACAAAC AAATGGTCCAATATATTTACAAATACACAAGTTATCCTGACCCTATATTG TTGATGAAAAGTGCTAGAAATAGTTGTTGGTCTAAAGATGCAGAATATGG ACTCTATTCCATCTATCAAGGGGGAATATTTGAGCTTAAGGAAAATGACA GAATTTTTGTTTCTGTAACAAATGAGCACTTGATAGACATGGACCATGAA GCCAGTTTTTTCGGGGCCTTTTTAGTTGGCTAACTGACCTGGAAAGAAAA AGCAATAACCTCAAAGTGACTATTCAGTTTTCAGGATGATACACTATGAA GATGTTTCAAAAAATCTGACCAAAACAAACAAACAGAAAACAGAAAACAA AAAAACCTCTATGCAATCTGAGTAGAGCAGCCACAACCAAAAAATTCTAC AACACACACTGTTCTGAAAGTGACTCACTTATCCCAAGAAAATGAAATTG CTGAAAGATCTTTCAGGACTCTACCTCATATCAGTTTGCTAGCAGAAATC TAGAAGACTGTCAGCTTCCAAACATTAATGCAATGGTTAACATCTTCTGT CTTTATAATCTACTCCTTGTAAAGACTGTAGAAGAAAGCGCAACAATCCA TCTCTCAAGTAGTGTATCACAGTAGTAGCCTCCAGGTTTCCTTAAGGGAC AACATCCTTAAGTCAAAAGAGAGAAGAGGCACCACTAAAAGATCGCAGTT TGCCTGGTGCAGTGGCTCACACCTGTAATCCCAACATTTTGGGAACCCAA GGTGGGTAGATCACGAGATCAAGAGATCAAGACCATAGTGACCAACATAG TGAAACCCCATCTCTACTGAAAGTGCAAAAATTAGCTGGGTGTGTTGGCA CATGCCTGTAGTCCCAGCTACTTGAGAGGCTGAGGCAGGAGAATCGTTTG AACCCGGGAGGCAGAGGTTGCAGTGTGGTGAGATCATGCCACTACACTCC AGCCTGGCGACAGAGCGAGACTTGGTTTCAAAAAAAAAAAAAAAAAAAAA CTTCAGTAAGTACGTGTTATTTTTTTCAATAAAATTCTATTACAGTATGT CAAAAAAAAAAAAAAAAAA
|
A
|
A61
|
A61K
|
38
|
19
|
||||
11764908
|
US20080316664A1-20081225
|
RESETTABLE MEMS MICRO-SWITCH ARRAY BASED ON CURRENT LIMITING APPARATUS
|
ACCEPTED
|
20081210
|
20081225
|
[]
|
H02H308
|
["H02H308"]
|
8072723
|
20070619
|
20111206
|
361
|
087000
|
62527.0
|
PATEL
|
DHARTI
|
[{"inventor_name_last": "Premerlani", "inventor_name_first": "William James", "inventor_city": "Scotia", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Caggiano", "inventor_name_first": "Robert Joseph", "inventor_city": "Wolcott", "inventor_state": "CT", "inventor_country": "US"}, {"inventor_name_last": "Subramanian", "inventor_name_first": "Kanakasabapathi", "inventor_city": "Clifton Park", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Kumfer", "inventor_name_first": "Brent Charles", "inventor_city": "Farmington", "inventor_state": "CT", "inventor_country": "US"}, {"inventor_name_last": "Pitzen", "inventor_name_first": "Charles Stephan", "inventor_city": "Avon", "inventor_state": "CT", "inventor_country": "US"}, {"inventor_name_last": "Lesslie", "inventor_name_first": "David James", "inventor_city": "Plainville", "inventor_state": "CT", "inventor_country": "US"}, {"inventor_name_last": "Wright", "inventor_name_first": "Joshua Isaac", "inventor_city": "Arlington", "inventor_state": "VA", "inventor_country": "US"}, {"inventor_name_last": "Thakre", "inventor_name_first": "Parag", "inventor_city": "Bangalore", "inventor_state": "", "inventor_country": "IN"}]
|
The present invention comprises a method for over-current protection. The method comprising monitoring a load current value of a load current passing through a plurality of micro-electromechanical switching system devices, determining if the monitored load current value varies from a predetermined load current value, and generating a fault signal in the event that the monitored load current value varies from the predetermined load current value. The method also comprises diverting the load current from the plurality of micro-electromechanical switching system, devices in response to the fault signal and determining if the variance in the load current value was due to a true fault trip or a false nuisance trip.
|
1. A method for over-current protection, the method comprising: monitoring a load current value of a load current passing through a plurality of micro-electromechanical switching system devices; determining if the monitored load current value varies from a predetermined load current value; generating a fault signal in the event that the monitored load current value varies from the predetermined load current value; diverting the load current from the plurality of micro-electromechanical switching system devices in response to the fault signal; and determining if the variance in the load current value was due to a true fault trip or a false nuisance trip. 2. The method of claim 1, wherein if it is determined that the variance in the load current value was due to a true fault trip, then the switches of the micro-electromechanical switching devices will remain open. 3. The method of claim 2, wherein if it is determined that the variance in the load current value was due to a false nuisance trip, then the switches of the micro-electromechanical switching devices will be closed. 4. The method of claim 3, further comprising monitoring a load voltage value. 5. The method of claim 4, further comprising determining if the monitored load voltage value varies from a predetermined load voltage value. 6. The method of claim 5, further comprising generating a fault signal in the event that the monitored load voltage/current value varies from the predetermined load voltage value. 7. The method of claim 6, further comprising determining if the variance in the load voltage/current value was due to a true fault trip or a false nuisance trip. 8. The method of claim 1, further comprising initiating a pulse circuit current in response to the generated fault signal. 9. The method of claim 8, where in response to the diversion of the load current the switches of the plurality of micro-electromechanical switching devices are opened. 10. An over-current protective device for electrical distribution systems, the device comprising: a user interface, wherein the user interface is configured to receive input control commands, the user interface further comprising a terminal block and a disconnect switch, the terminal block being in communication with the disconnect switch; a logic circuit in communication with the user interface; a power stage circuit in communication with the logic circuit; an MEMS protection circuit in communication with the logic circuit and the power stage circuit; and a switching circuit in communication with the MEMS protection circuit, wherein the switching circuit comprises a plurality of micro-electromechanical system switching devices. 11. The device of claim 10, wherein the plurality of micro-electromechanical system switching devices of the switching circuit are in communication with the disconnect switch of the user interface. 12. The device of claim 11, wherein the logic circuit is configured to monitor a load current. 13. The device of claim 12, wherein the logic circuit is configured to monitor a load voltage. 14. The device of claim 13, where in response to a monitored load current or load voltage varying from a predetermined value, a fault signal is generated and transmitted to the MEMS protection circuit. 15. The device of claim 14, where in response to the generated and transmitted fault signal being received at the MEMS protection circuit, the MEMS protection circuit diverts a load current from the micro-electromechanical system switching devices of the switching circuit. 16. The device of claim 15, where the micro-electromechanical system switches are opened in response to the diversion of the load current. 17. The device of claim 16, wherein the control circuit is configured to further determine if the varying of the monitored current or voltage was in response to a true fault trip or a false nuisance trip. 18. The device of claim 17, wherein the switching circuit further comprises an isolator contactor that is in communication with the plurality of micro-electromechanical system switching devices, the isolator contactor being configured to isolate a line to a load in response to the switches of the plurality of micro-electromechanical system switching devices being in an open position. 19. The device of claim 18, wherein if it is determined that the varying in the current load value was due to a true fault trip, then the switches of the micro-electromechanical switching devices will remain open. 20. The device of claim 19, wherein if it is determined that the varying in the current load value was due to a false nuisance trip, then the switches of the micro-electromechanical switching devices will be closed.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Embodiments of the invention relate generally to a switching device for switching off a current in a current path, and more particularly to micro-electromechanical system based switching devices. To protect against fire and equipment damage, electrical equipment and wiring must be protected from conditions that result in current levels above their ratings. Over-current conditions are classified by the time required before damage occurs and are grouped into two categories: timed over-currents and instantaneous over-currents. Timed over-current faults are the less severe variety and require the protective equipment to deactivate the circuit after a given time period, which depends on the level of the fault. Timed over-current faults are typically current levels just above rated and up to 8-10 times rated. The system cabling and equipment can handle these faults for a period of time but the protective equipment should deactivate the circuit if the current levels don't recede. Typically timed faults result from either mechanically overloaded equipment or high impedance paths between opposite polarity lines—line to line, line to ground, or line to neutral. Instantaneous over-currents, also termed short circuit faults, are severe faults and involve current levels of 8-10 time rated current and above. These faults result from low impedance paths between opposite polarity lines—line to line, line to ground, or line to neutral—and need to be removed from the system immediately. Short circuit faults involve extreme currents and can be extremely damaging to equipment and dangerous to personnel. The longer these faults persist on the system the more energy is released and the more damage occurs, it is of vital importance to minimize the response time and thus the let-through energy during a short circuit fault. A circuit breaker is an electrical device designed to protect electrical equipment from damage caused by faults in the circuit. Traditionally, most conventional circuit breakers include bulky electromechanical switches. Unfortunately, these conventional circuit breakers are large in size thereby necessitating use of a large force to activate the switching mechanism. Additionally, the switches of these circuit breakers generally operate at relatively slow speeds. Further, these circuit breakers are disadvantageously complex to build, and thus expensive to fabricate. In addition, when contacts of a switching mechanism within a conventional circuit breaker are physically separated, an arc is typically formed between the contacts and continues to carry current until the current in the circuit ceases. Moreover, energy associated with the arc is generally undesirable to both equipment and personnel. A contactor is an electrical device that is designed to switch an electrical load ON and OFF upon command. Traditionally, electromechanical contactors are employed in control gear, where the electromechanical contactors are capable of handling switching currents up to their interrupting capacity. Electromechanical contactors may also find application in power systems for switching currents. However, fault currents in power systems are typically greater than the interrupting capacity of the electromechanical contactors. Accordingly, to employ electromechanical contactors in power system applications it may be desirable to protect the contactor from damage by backing it up with a series device that is sufficiently last acting to interrupt fault currents prior to the contactor opening at all values of current above the interrupting capacity of the contactor. Electrical systems presently use either a fuse or a circuit breaker to perform over-current protection. Fuses rely on heating effects (i.e., I 2 t) to operate. They are designed as weak points in the circuit and each successive fuse closer to the load must be rated for smaller & smaller currents. In a short circuit condition all upstream fuses see the same heating energy and the weakest one, by design the closest to the fault, will be the first to operate. Fuses however are one-time devices and must be replaced after a fault occurs. Previously conceived solutions to facilitate use of contactors in power systems have include vacuum contactors, vacuum interrupters and air break contactors. Unfortunately, contactors such as vacuum contactors do not lend themselves to easy visual inspection as the contactor tips are encapsulated in a sealed, evacuated enclosure. Further, while the vacuum contactors are well suited for handling the switching of large motors, transformers and capacitors, they are known to cause damaging transient over voltages, particularly when the load is switched off. Further, electromechanical contactors generally use mechanical switches. However, as these mechanical switches tend to switch at a relatively slow speed predictive techniques are required in order to estimate occurrence of a zero crossing, often tens of milliseconds before the switching event is to occur. Such zero crossing prediction is prone to error as many transients may occur in this time. As an alternative to slow mechanical and electromechanical switches, fast solid-state switches have been employed in high speed switching applications. As will be appreciated, these solid-state switches switch between a conducting state and a non-conducting state through controlled application of a voltage or bias. For example, by reverse biasing a solid-state switch, the switch may be transitioned into a non-conducting state. However, since solid-state switches do not create a physical gap between contacts when they are switched into a non-conducing state, they experience leakage current. Further, due to internal resistances, when solid-state switches operate in a conducting state, they experience a voltage drop. Both the voltage drop and leakage current contribute to the generation of excess heat under normal operating circumstances, which may be detrimental to switch performance and life. Moreover, due at least in part to the inherent leakage current associated with solid-state switches, their use in circuit breaker applications is not possible.
|
<SOH> BRIEF DESCRIPTION OF THE INVENTION <EOH>Exemplary embodiments of the present invention comprise a method for over-current protection. The method comprising monitoring a load current value of a load current passing through a plurality of micro-electromechanical switching system devices, determining if the monitored load current value varies from a predetermined load current value, and generating a fault signal in the event that the monitored load current value varies from the predetermined load current value. The method also comprises diverting the load current from the plurality of micro-electromechanical switching system devices in response to the fault signal and determining if the variance in the load current value was due to a true fault trip or a false nuisance trip. Another exemplary embodiment of the present invention comprises an over-current protective device for electrical distribution systems. The device comprising a user interface, wherein the user interface is configured to receive input control commands, the user interface further comprising a terminal block in communication with a disconnect switch, a logic circuit in communication with the user interface, and a power stage circuit in communication with the logic circuit. The device also comprises an MEMS protection circuit in communication with the logic circuit and the power staging circuit and a switching circuit in communication with the MEMS protection circuit, wherein the switching circuit comprises a plurality of micro-electromechanical system switching devices.
|
BACKGROUND OF THE INVENTION Embodiments of the invention relate generally to a switching device for switching off a current in a current path, and more particularly to micro-electromechanical system based switching devices. To protect against fire and equipment damage, electrical equipment and wiring must be protected from conditions that result in current levels above their ratings. Over-current conditions are classified by the time required before damage occurs and are grouped into two categories: timed over-currents and instantaneous over-currents. Timed over-current faults are the less severe variety and require the protective equipment to deactivate the circuit after a given time period, which depends on the level of the fault. Timed over-current faults are typically current levels just above rated and up to 8-10 times rated. The system cabling and equipment can handle these faults for a period of time but the protective equipment should deactivate the circuit if the current levels don't recede. Typically timed faults result from either mechanically overloaded equipment or high impedance paths between opposite polarity lines—line to line, line to ground, or line to neutral. Instantaneous over-currents, also termed short circuit faults, are severe faults and involve current levels of 8-10 time rated current and above. These faults result from low impedance paths between opposite polarity lines—line to line, line to ground, or line to neutral—and need to be removed from the system immediately. Short circuit faults involve extreme currents and can be extremely damaging to equipment and dangerous to personnel. The longer these faults persist on the system the more energy is released and the more damage occurs, it is of vital importance to minimize the response time and thus the let-through energy during a short circuit fault. A circuit breaker is an electrical device designed to protect electrical equipment from damage caused by faults in the circuit. Traditionally, most conventional circuit breakers include bulky electromechanical switches. Unfortunately, these conventional circuit breakers are large in size thereby necessitating use of a large force to activate the switching mechanism. Additionally, the switches of these circuit breakers generally operate at relatively slow speeds. Further, these circuit breakers are disadvantageously complex to build, and thus expensive to fabricate. In addition, when contacts of a switching mechanism within a conventional circuit breaker are physically separated, an arc is typically formed between the contacts and continues to carry current until the current in the circuit ceases. Moreover, energy associated with the arc is generally undesirable to both equipment and personnel. A contactor is an electrical device that is designed to switch an electrical load ON and OFF upon command. Traditionally, electromechanical contactors are employed in control gear, where the electromechanical contactors are capable of handling switching currents up to their interrupting capacity. Electromechanical contactors may also find application in power systems for switching currents. However, fault currents in power systems are typically greater than the interrupting capacity of the electromechanical contactors. Accordingly, to employ electromechanical contactors in power system applications it may be desirable to protect the contactor from damage by backing it up with a series device that is sufficiently last acting to interrupt fault currents prior to the contactor opening at all values of current above the interrupting capacity of the contactor. Electrical systems presently use either a fuse or a circuit breaker to perform over-current protection. Fuses rely on heating effects (i.e., I2t) to operate. They are designed as weak points in the circuit and each successive fuse closer to the load must be rated for smaller & smaller currents. In a short circuit condition all upstream fuses see the same heating energy and the weakest one, by design the closest to the fault, will be the first to operate. Fuses however are one-time devices and must be replaced after a fault occurs. Previously conceived solutions to facilitate use of contactors in power systems have include vacuum contactors, vacuum interrupters and air break contactors. Unfortunately, contactors such as vacuum contactors do not lend themselves to easy visual inspection as the contactor tips are encapsulated in a sealed, evacuated enclosure. Further, while the vacuum contactors are well suited for handling the switching of large motors, transformers and capacitors, they are known to cause damaging transient over voltages, particularly when the load is switched off. Further, electromechanical contactors generally use mechanical switches. However, as these mechanical switches tend to switch at a relatively slow speed predictive techniques are required in order to estimate occurrence of a zero crossing, often tens of milliseconds before the switching event is to occur. Such zero crossing prediction is prone to error as many transients may occur in this time. As an alternative to slow mechanical and electromechanical switches, fast solid-state switches have been employed in high speed switching applications. As will be appreciated, these solid-state switches switch between a conducting state and a non-conducting state through controlled application of a voltage or bias. For example, by reverse biasing a solid-state switch, the switch may be transitioned into a non-conducting state. However, since solid-state switches do not create a physical gap between contacts when they are switched into a non-conducing state, they experience leakage current. Further, due to internal resistances, when solid-state switches operate in a conducting state, they experience a voltage drop. Both the voltage drop and leakage current contribute to the generation of excess heat under normal operating circumstances, which may be detrimental to switch performance and life. Moreover, due at least in part to the inherent leakage current associated with solid-state switches, their use in circuit breaker applications is not possible. BRIEF DESCRIPTION OF THE INVENTION Exemplary embodiments of the present invention comprise a method for over-current protection. The method comprising monitoring a load current value of a load current passing through a plurality of micro-electromechanical switching system devices, determining if the monitored load current value varies from a predetermined load current value, and generating a fault signal in the event that the monitored load current value varies from the predetermined load current value. The method also comprises diverting the load current from the plurality of micro-electromechanical switching system devices in response to the fault signal and determining if the variance in the load current value was due to a true fault trip or a false nuisance trip. Another exemplary embodiment of the present invention comprises an over-current protective device for electrical distribution systems. The device comprising a user interface, wherein the user interface is configured to receive input control commands, the user interface further comprising a terminal block in communication with a disconnect switch, a logic circuit in communication with the user interface, and a power stage circuit in communication with the logic circuit. The device also comprises an MEMS protection circuit in communication with the logic circuit and the power staging circuit and a switching circuit in communication with the MEMS protection circuit, wherein the switching circuit comprises a plurality of micro-electromechanical system switching devices. BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: FIG. 1 is a block diagram of an exemplary MEMS based switching system in accordance with an embodiment of the invention. FIG. 2 is schematic diagram illustrating the exemplary MEMS based switching system depicted in FIG. 1. FIG. 3 is a block diagram of an exemplary MEMS based switching system in accordance with an embodiment of the invention and alternative to the system depicted in FIG. 1. FIG. 4 is a schematic diagram, illustrating the exemplary MEMS based switching system depicted in FIG. 3. FIG. 5 is a block diagram of an exemplary MEMS based over-current protective component in accordance with an embodiment of the present invention. FIG. 6 is a flow diagram detailing a methodology for utilizing a MEMS enabled over-current protective component in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of various embodiments of the present invention. However, those skilled in the art will understand that embodiments of the present invention may be practiced without these specific details, that the present invention is not limited to the depicted embodiments, and that the present invention may be practiced in a variety of alternative embodiments. In other instances, well known methods, procedures, and components have not been described in detail. Further, various operations may be described as multiple discrete steps performed in a manner that is helpful for understanding embodiments of the present invention. However, the order of description should not be construed as to imply that these operations need be performed in the order they are presented, or that they are even order dependent. Moreover, repeated usage of the phrase “in an embodiment” does not necessarily refer to the same embodiment, although it may. Lastly, the terms “comprising,” “including,” “having,” and the like, as used in the present application, are intended to be synonymous unless otherwise indicated. FIG. 1 illustrates a block diagram of an exemplary arc-less MEMS based switching system 10, in accordance with aspects of the present invention. Presently, MEMSs generally refers to micron-scale structures that, for example, can integrate a multiplicity of functionally distinct elements. Such elements including, but not being limited to, mechanical elements, electromechanical elements, sensors, actuators, and electronics, on a common substrate through micro-fabrication technology. It is contemplated, however, that many techniques and structures presently available in MEMS devices will in just a few years be available via nanotechnology-based devices, that is, structures that may be smaller than 100 nanometers in size. Accordingly, even though example embodiments described throughout this document may refer to MEMS-based switching devices, it is submitted that the inventive aspects of the present invention should be broadly construed and should not be limited to micron-sized devices. As illustrated in FIG. 1, the arc-less MEMS based switching system 10 is shown as including MEMS based switching circuitry 12 and arc suppression circuitry 14, where the arc suppression circuitry 14 (alternatively referred to Hybrid Arc-less Limiting Technology (HALT)), is operatively coupled to the MEMS based switching circuitry 12. Within exemplary embodiments of the present invention, the MEMS based switching circuitry 12 may be integrated in its entirety with the arc suppression circuitry 14 in a single package 16. In further exemplary embodiments, only specific portions or components of the MEMS based switching circuitry 12 may be integrated in conjunction with the arc suppression circuitry 14. In a presently contemplated configuration as will be described in greater detail with reference to FIG. 2, the MEMS based switching circuitry 12 may include one or more MEMS switches. Additionally, the arc suppression circuitry 14 may include a balanced diode bridge and a pulse circuit. Further, the arc suppression circuitry 14 may be configured to facilitate suppression of an arc formation between contacts of the one or more MEMS switches. It may be noted that the arc suppression circuitry 14 may be configured to facilitate suppression of an arc formation in response to an alternating current (AC) or a direct current (DC). Turning now to FIG. 2, a schematic diagram 18 of the exemplary arc-less MEMS based switching system depicted in FIG. 1 is illustrated in accordance with an embodiment. As noted with reference to FIG. 1, the MEMS based switching circuitry 12 may include one or more MEMS switches, in the illustrated exemplary embodiment a first MEMS switch 20 is depleted as having a first contact 22, a second contact 24 and a third contact 26. In one embodiment the first contact 22 may be configured as a drain, the second contact 24 may be configured as a source and the third contact 26 may be configured as a gate. Further, as illustrated in FIG. 2, a voltage snubber circuit 33 may be coupled in parallel with the MEMS switch 20 and configured to limit voltage overshoot during fast contact separation as will be explained in greater detail hereinafter. In further embodiments, the snubber circuit 33 may include a snubber capacitor (see 76, FIG. 4) coupled in series with a snubber resistor (see FIG. 4, reference number 78). The snubber capacitor may facilitate improvement in transient voltage sharing during the sequencing of the opening of the MEMS switch 20. Additionally, the snubber resistor may suppress any pulse of current generated by the snubber capacitor during closing operation of the MEMS switch 20. In yet further embodiments, the voltage snubber circuit 33 may include a metal oxide varistor (MOV) (not shown). In accordance with further aspects of the present technique, a load circuit 40 may be coupled in series with the first MEMS switch 20. The load circuit 40 may include a voltage source VBUS 44. In addition, the load circuit 40 may also include a load inductance 46 LLOAD, where the load inductance LLOAD 46 is representative of a combined load inductance and a bus inductance viewed by the load circuit 40. The load circuit 40 may also include a load resistance RLOAD 48 representative of a combined load resistance viewed by the load circuit 40. Reference numeral 50 is representative of a load circuit current ILOAD that may flow through the load circuit 40 and the first MEMS switch 20. As noted with reference to FIG. 1, the arc suppression circuitry 14 may include a balanced diode bridge. In the illustrated embodiment, a balanced diode bridge 28 is depleted as having a first branch 29 and a second branch 31. As used herein, the term “balanced diode bridge” is used to represent a diode bridge that is configured in such a manner that voltage drops across both the first and second branches 29, 31 are substantially equal. The first branch 29 of the balanced diode bridge 28 may include a first diode D1 30 and a second diode D2 32 coupled together to form a first series circuit. In a similar fashion, the second branch 31 of the balanced diode bridge 28 may include a third diode D3 34 and a fourth diode D4 36 operatively coupled together to form a second series circuit. In an exemplary embodiment, the first MEMS switch 20 may be coupled in parallel across midpoints of the balanced diode bridge 28. The midpoints of the balanced diode bridge may include a first midpoint located between the first and second diodes 30, 32 and a second midpoint located between the third and fourth diodes 34, 36. Further, the first MEMS switch 20 and the balanced diode bridge 28 may be tightly packaged to facilitate minimization of parasitic inductance caused by the balanced diode bridge 28 and in particular, the connections to the MEMS switch 20. It must be noted that, in accordance with exemplary aspects of the present technique, the first MEMS switch 20 and the balanced diode bridge 28 are positioned relative to one another such that the inherent inductance between the first MEMS switch 20 and the balanced diode bridge 28 produces a di/dt voltage less than a few percent of the voltage across the drain 22 and source 24 of the MEMS switch 20 when carrying a transfer of the load current to the diode bridge 28 during the MEMS switch 20 turn-off which will be described in greater detail hereinafter. In further embodiments, the first MEMS switch 20 may be integrated with the balanced diode bridge 28 in a single package 38 or optionally within the same die with the intention of minimizing the inductance interconnecting the MEMS switch 20 and the diode bridge 28. Additionally, the arc suppression circuitry 14 may include a pulse circuit 52 operatively coupled in association with the balanced diode bridge 28. The pulse circuit 52 may be configured to detect a switch condition and initiate opening of the MEMS switch 20 responsive to the switch condition. As used herein, the term “switch condition” refers to a condition that triggers changing a present operating state of the MEMS switch 20. For example, the switch condition may result in changing a first closed state of the MEMS switch 20 to a second open state or a first open state of the MEMS switch 20 to a second closed state. A switch condition may occur in response to a number of actions including but not limited to a circuit fault or switch ON/OFF request. The pulse circuit 52 may include a pulse switch 54 and a pulse capacitor CPULSE 56 series coupled to the pulse switch 54. Further, the pulse circuit may also include a pulse inductance LPULSE 58 and a first diode DP 60 coupled in series with the pulse switch 54. The pulse inductance LPULSE 58, the diode DP 60, the pulse switch 54 and the pulse capacitor CPULSE 56 may be coupled in series to form a first branch of the pulse circuit 52, where the components of the first branch may be configured to facilitate pulse current shaping and timing. Also, reference numeral 62 is representative of a pulse circuit current IPULSE that may flow through the pulse circuit 52. In accordance with aspects of the present invention, the MEMS switch 20 may be rapidly switched (for example, on the order of picoseconds or nanoseconds) from a first closed state to a second open state while carrying a current albeit at a near-zero voltage. This may be achieved through the combined operation of the load circuit 40, and pulse circuit 52 including the balanced diode bridge 28 coupled in parallel across contacts of the MEMS switch 20. Reference is now made to FIG. 3, which illustrates a block diagram of an exemplary soft switching system 11, in accordance with aspects of the present invention. As illustrated in FIG. 3, the soft switching system 11 includes switching circuitry 12, detection circuitry 70, and control circuitry 72 operatively coupled together. The detection circuitry 70 may be coupled to the switching circuitry 12 and configured to detect an occurrence of a zero crossing of an alternating source voltage in a load circuit (hereinafter “source voltage”) or an alternating current in the load circuit (hereinafter referred to as “load circuit current”). The control circuitry 72 may be coupled to the switching circuitry 12 and the detection circuitry 70, and may be configured to facilitate arc-less switching of one or more switches in the switching circuitry 12 responsive to a detected zero crossing of the alternating source voltage or the alternating load circuit current. In one embodiment, the control circuitry 72 may be configured to facilitate arc-less switching of one or more MEMS switches comprising at least part of the switching circuitry 12. In accordance with one aspect of the invention, the soft switching system 11 may be configured to perform soft or point-on-wave (PoW) switching whereby one or more MEMS switches in the switching circuitry 12 may be closed at a time when the voltage across the switching circuitry 12 is at or very close to zero and opened at a time when the current through the switching circuitry 12 is at or close to zero. By closing the switches at a time when the voltage across the switching circuitry 12 is at or very close to zero, pre-strike arcing can be avoided by keeping the electric field low between the contacts of the one or more MEMS switches as they close; even if multiple switches do not all close at the same time. Similarly, by opening the switches at a time when the current through the switching circuitry 12 is at or close to zero, the soft switching system 11 can be designed so that the current in the last switch to open in the switching circuitry 12 falls within the design capability of the switch. As mentioned above, the control circuitry 72 may be configured to synchronize the opening and closing of the one or more MEMS switches of the switching circuitry 12 with the occurrence of a zero crossing of an alternating source voltage or an alternating load circuit current. Turning to FIG. 4, a schematic diagram 19 of one embodiment of the soft switching system 11 of FIG. 3 is illustrated. In accordance with the illustrated embodiment, the schematic diagram 19 includes one example of the switching circuitry 12, the detection circuitry 70 and the control circuitry 72. Although for the purposes of description, FIG. 4 illustrates only a single MEMS switch 20 in switching circuitry 12, the switching circuitry 12 may nonetheless include multiple MEMS switches depending upon, for example, the current and voltage handling requirements of the soft switching system 11. In an exemplary embodiment, the switching circuitry 12 may include a switch module including multiple MEMS switches coupled together in a parallel configuration to divide the current amongst the MEMS switches. In a further exemplary embodiment, the switching circuitry 12 may include an array of MEMS switches coupled in a series configuration to divide the voltage amongst the MEMS switches. In a yet further exemplary embodiment, the switching circuitry 12 may include an array of MEMS switch modules coupled together in a series configuration to concurrently divide the voltage amongst the MEMS switch modules and divide the current amongst the MEMS switches in each module. Furthermore, the one or more MEMS switches of the switching circuitry 12 may be integrated into a single package 74. The exemplary MEMS switch 20 may include three contacts. In an exemplary embodiment, a first contact may be configured as a drain 22, a second contact may be configured as a source 24, and the third contact may be configured as a gate 26. In one embodiment, the control circuitry 72 may be coupled to the gate contact 26 to facilitate switching a current state of the MEMS switch 20. Also, in additional exemplary embodiments damping circuitry (snubber circuit) 33 may be coupled in parallel with the MEMS switch 20 to delay appearance of voltage across the MEMS switch 20. As illustrated, the damping circuitry 33 may include a snubber capacitor 76 coupled in series with a snubber resistor 78. The MEMS switch 20 may be coupled in series with a load circuit 40, as further illustrated in FIG. 4. In a presently contemplated configuration, the load circuit 40 may include a voltage source VSOURCE 44, and may possess a representative load inductance LLOAD 46 and a load resistance RLOAD 48. In one embodiment, the voltage scarce VSOURCE 44 (also referred to as an AC voltage source) may be configured to generate the alternating source voltage and the alternating load current ILOAD 50. As previously noted, the detection circuitry 70 may be configured to detect occurrence of a zero crossing of the alternating source voltage or the alternating load current ILOAD 50 in the load circuit 40. The alternating source voltage may be sensed via the voltage sensing circuitry 80 and the alternating load current ILOAD 50 may be sensed via the current sensing circuitry 82. The alternating source voltage and the alternating load current may be sensed continuously or at discrete periods for example. A zero crossing of the source voltage may be detected through, for example, use of a comparator such as the illustrated zero voltage comparator 84. The voltage sensed by the voltage sensing circuitry 80 and a zero voltage reference 86 may be employed as inputs to the zero voltage comparator 84. In turn, an output signal 88 representative of a zero crossing of the source voltage of the load circuit 40 may be generated. Similarly, a zero crossing of the load current ILOAD 50 may also be detected through use of a comparator such as the illustrated zero current comparator 92. The current sensed by the current sensing circuitry 82 and a zero current reference 90 may be employed as inputs to the zero current comparator 92. In turn, an output signal 94 representative of a zero crossing of the load current ILOAD 50 may be generated. The control circuitry 72, may in turn utilize the output signals 88 and 94 to determine when to change (for example, open or close) the current operating state of the MEMS switch 20 (or array of MEMS switches). More specifically, the control circuitry 72 may be configured to facilitate opening of the MEMS switch 20 in an arc-less manner to interrupt or open the load circuit 40 responsive to a detected zero crossing of the alternating load current ILOAD 50. Additionally, the control circuitry 72 may be configured to facilitate closing of the MEMS switch 20 in an arc-less manner to complete the load circuit 40 responsive to a detected zero crossing of the alternating source voltage. The control circuitry 72 may determine whether to switch the present operating state of the MEMS switch 20 to a second operating state based at least in part upon a state of an Enable signal 96. The Enable signal 96 may be generated as a result of a power off command in a contactor application, for example. Further, the Enable signal 96 and the output signals 88 and 94 may be used as input signals to a dual D flip-flop 98 as shown. These signals may be used to close the MEMS switch 20 at a first source voltage zero after the Enable signal 96 is made active (for example, rising edge triggered), and to open the MEMS switch 20 at the first load current zero a tier the Enable signal 96 is deactivated (for example, falling edge triggered). With respect to the illustrated schematic diagram 19 of FIG. 4, every time the Enable signal 96 is active (either high or low depending upon the specific implementation) and either output signal 88 or 94 indicates a sensed voltage or current zero, a trigger signal 172 may be generated. Additionally, the trigger signal 172 may be generated via a NOR gate 100. The trigger signal 102 may in turn be passed through a MEMS gate driver 104 to generate a gate activation signal 106 which may be used to apply a control voltage to the gate 26 of the MEMS switch 20 (or gates in the case of a MEMS array). As previously noted, in order to achieve a desirable current rating for a particular application, a plurality of MEMS switches may be operatively coupled in parallel (for example, to form a switch module) in lieu of a single MEMS switch. The combined capabilities of the MEMS switches may be designed to adequately carry the continuous and transient overload current levels that may be experienced by the load circuit. For example, with a 10-amp RMS motor contactor with a 6× transient overload, there should be enough switches coupled in parallel to carry 60 amps RMS for 10 seconds. Using point-on-wave switching to switch the MEMS switches within 5 microseconds of reaching current zero, there will be 160 milliamps instantaneous, flowing at contact opening. Thus, for that application, each MEMS switch should be capable of “warm-switching” 160 milliamps, and enough of them should be placed in parallel to carry 60 amps. On the other hand, a single MEMS switch should be capable of interrupting the amount of current that will be flowing at the moment of switching. FIG. 5 shows a block diagram of a MEMS based over-current protection device 110 that may be implemented within exemplary embodiments of the present invention. The device 110 receives user control inputs at the user interface 115, the user interface 115 providing a control and input interface for a user to interact with the device 110. Within the user interface 115, three-phase line power inputs 114 are received at a terminal block 116, wherein the line power input 114 is fed to the terminal block 116, and then respectively through to the power circuit 135 and the switch module 120. User inputs can be utilized to make determinations in regard to operations such as whether to open or close the device 110 input trip levels within predetermined ranges. As such, user input can be in the form of input from a trip adjustment potentiometer, an electrical signal from a human interface (for example, from a push-button interface), or control equipment that are routed to the user interface 115. User input also can be input directly to activate a disconnect switch 117 via the terminal block 116, wherein the disconnect switch is structurally configured to provide lockable isolation of the device 110 in order to protect personnel during the service and maintenance of downstream equipment. User input is used to control the MEMS switching as well as provide user adjustability in regard to trip-time curves. The power circuit 135 performs basic functions to provide power for the additional circuits, such as transient suppression, voltage scaling & isolation, and EMI filtering. The over-current protection device 110 further comprises logic circuitry 125, wherein the logic circuitry 125 is responsible controlling the normal operation as well as recognizing fault conditions (such as setting the trip-time curve for timed over-currents (126), allowing programmability or adjustability, controlling the closing/re-closing of specified logic (126, 128), etc. . . . ). The current/voltage sensing component 127 provides the voltage and current measurements needed to implement the required logic for over-current protection operations, and for maintaining responsibility the energy diversion circuits utilize for cold switching operations, wherein the operations are accomplished using the above mentioned charging 132 and pulse circuits 133 in addition to the diode bridge 134. The MEMS protection circuitry 130 is similar in configuration and operation to the pulse circuit 52 as described above. Lastly, the switching circuitry 120 is implemented, wherein the switching circuit comprises a switching module 122 containing the MEMS device arrays. The switching module 122 is similar in configuration and operation to the MEMS switch 20 as described above. In further embodiments of the present invention the switching circuit 120 further comprises an isolation contactor 123, wherein the isolation contactor is utilized to isolate input line 114 to output load 141 when the over-protection current device 110 is not activated or when the over-current protection device 110 is tripped. The over-current protection device 110 of FIG. 5 as configured has the capability to replace fuses or circuit breakers within power systems. In an exemplary embodiment, the logic circuit 125 includes some or all functional characteristics similar to those of an electronic trip unit typically employed with a circuit breaker, which includes a processing circuit responsive to signals from current and voltage sensors, logic provided by a time-current characteristic curve, and algorithms productive of trip signals, current metering information, and/or communications with an external device, thereby providing device 110 with all of the functionality of a circuit breaker with an electronic trip unit. Within exemplary embodiments of the present invention line inputs 114 are attached to the terminal block 116 which in turn feeds a disconnect switch that feeds the switching module 120 through the isolation contactor 123, and finally out to a load output 141. The disconnect switch 117 is utilized for service disconnection in the event of needed maintenance within the device or any downstream equipment. As such, the MEMS switch enabled over-current protection device 110 provides the main switching capability and the fault interruption for the line power. Within further exemplary embodiments of the present invention, power for the logic circuit 125 is drawn from a phase-to-phase differential and thereafter fed through to a surge suppression component 136. A main power stage component 137 distributes power at various voltages in order to feed the control logic 138, the over-current protection device charging circuits 139, and the MEMS switch gate voltages 140. A current and voltage sensor 127 feeds the timed and instantaneous over-current logic 128, which in turn controls the MEMS switch gate voltage 140 and the MEMS protection circuit's 130 triggering circuits 131. FIG. 6 shows a flow diagram detailing the utilization of the over-current protection device 110 as a method for providing short-circuit protection and eliminating the issue of nuisance tripping. At step 605, the current/voltage sensor 127 of the over-current protection component 110 continuously monitors both the line current level and the line voltage level within a system. At step 610 a determination is made as to if the level of the current/voltage vary from a predetermined range. In the event that the current/voltage level has not varied from a prescribed range the sensor 127 continues its monitoring operations. In the event that the monitored current/voltage levels do vary from a predetermined range, a fault signal is generated at the instantaneous over-current logic 128 to indicate that a system determined variance in current/voltage level (step 615) has been detected. In conjunction with the generation of the fault signal, at step 620 a fault counter is incremented in order to track the occurrence of faults originating within a system. At step 625 the fault signal is delivered to the trigger circuit 131, wherein the trigger circuit initiates an over-current protection pulsing operation at the MEMS protection circuit 130. The pulsing operation involves the activation of the pulse circuit 133, the activation of which results in the closing of the LC pulse circuit. Once the LC pulse circuit 133 has been closed the charging circuit 132 discharges through the balanced diode bridge 134. The pulse current through the diode bridge 134 creates a resulting short across the MEMS array switches of the switching module 122 and diverts the load current into the diode bridge and around the MEMS array (step 630) (see FIGS. 2 and 5). Under the protective pulse operation, the MEMS switches of the switch module 122 can be opened with a zero or close to zero current (step 635). After the opening of the MEMS switches at step 635, at step 640 the incremental fault count information that has accumulating within a system is retrieved. At step 645 a determination is made as to if the resultant trip action was the result of a non-nuisance trip or a nuisance trip action that may have been caused by detected noise on the power line. In the event that the fault count is less than one (1), then a determination is made that the resulting trip was a nuisance trip (step 650), then the component will close (or reset) the MEMS switches and continue its current/voltage monitoring operations, in the event that the fault count is greater than one (1), then a determination is made that the resulting trip was a non-nuisance trip (step 655), and then at step 660 the component will leave the MEMS switches open and wait for switch resetting services. The present invention provides enhanced protection as compared to current fuses and circuit breaker devices and can be completely implemented in place of the fore-mentioned devices. While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
|
H
|
H02
|
H02H
|
3
|
08
|
|||
11809719
|
US20110068350A1-20110324
|
Diamond semiconductor devices and associated methods
|
ACCEPTED
|
20110309
|
20110324
|
[]
|
H01L310312
|
["H01L310312", "H01L21223"]
|
8110846
|
20070531
|
20120207
|
257
|
079000
|
63495.0
|
TORNOW
|
MARK
|
[{"inventor_name_last": "Sung", "inventor_name_first": "Chien-Min", "inventor_city": "Tansui", "inventor_state": "", "inventor_country": "TW"}]
|
Semiconductor devices and methods for making such devices are provided. One such method may include forming a transparent diamond layer having a SiC layer coupled thereto, where the SiC layer has a crystal structure that is substantially epitaxially matched to the transparent diamond layer, forming epitaxially a plurality of semiconductor layers on the SiC layer, and coupling a diamond substrate to at least one of the plurality of semiconductor layers such that the diamond support is oriented parallel to the transparent diamond layer. In one aspect such a method may further include electrically coupling at least one of a p-type electrode or an n-type electrode to at least one of the plurality of semiconductor layers.
|
1. A semiconductor device, comprising: a diamond substrate; a transparent diamond layer positioned parallel to the diamond substrate; a plurality of semiconductor layers coupled between the transparent diamond layer and the diamond substrate; and a SiC layer coupled directly to the transparent diamond layer and facing the plurality of semiconductor layers, such that the SiC layer is coupled directly to at least one of the plurality of semiconductor layers, and wherein light generated in the semiconductor layers is emitted through the transparent diamond layer. 2. The device of claim 1, wherein the semiconductor device is an LED device and the plurality of semiconductor layers is a plurality of LED nitride layers. 3. The device of claim 1, wherein the plurality of semiconductor layers is arranged in series between the diamond substrate and the transparent diamond layer. 4. (canceled) 5. The device of claim 1, wherein the SiC layer is a single crystal SiC layer. 6. The device of claim 5, wherein the SiC layer has a crystal lattice that is substantially epitaxially matched to the transparent diamond layer. 7. The device of claim 5, wherein the SiC layer has a crystal lattice that is substantially epitaxially matched to at least one of the semiconductor layers. 8. The device of claim 1, further comprising at least one of a p-type electrode or an n-type electrode electrically coupled to at least one of the semiconductor layers. 9. The device of claim 8, wherein the diamond substrate is p-type doped, and the p-type electrode is the p-type doped diamond substrate. 10. The device of claim 9, wherein the diamond substrate is doped with boron to form the p-type doped diamond substrate. 11. The device of claim 1, wherein the plurality of semiconductor layers includes at least one member selected from the group consisting of silicon germanium, gallium arsenide, gallium nitride, germanium, zinc sulfide, gallium phosphide, gallium antimonide, gallium indium arsenide phosphide, aluminum phosphide, aluminum arsenide, aluminum gallium arsenide, gallium nitride, boron nitride, aluminum nitride, indium arsenide, indium phosphide, indium antimonide, indium nitride, and combinations thereof. 12. The device of claim 11, wherein at least one of the semiconductor layers is gallium nitride. 13. The device of claim 11, wherein at least one of the semiconductor layers is aluminum nitride. 14. A method of making a semiconductor device, comprising: forming a transparent diamond layer having a SiC layer coupled thereto, where the SiC layer has a crystal structure that is substantially epitaxially matched to the transparent diamond layer; depositing epitaxially at least one of a plurality of semiconductor layers on the SiC layer opposite the transparent diamond layer; and coupling a diamond substrate to at least one of the plurality of semiconductor layers such that the diamond substrate is oriented parallel to the transparent diamond layer, and the plurality of semiconductor layers are located between the transparent diamond layer and the diamond substrate. 15. The method of claim 14, further comprising electrically coupling at least one of a p-type electrode or an n-type electrode to at least one of the plurality of semiconductor layers. 16. The method of claim 14, wherein the plurality of semiconductor layers includes at least one member selected from the group consisting of silicon germanium, gallium arsenide, gallium nitride, germanium, zinc sulfide, gallium phosphide, gallium antimonide, gallium indium arsenide phosphide, aluminum phosphide, aluminum arsenide, aluminum gallium arsenide, gallium nitride, boron nitride, aluminum nitride, indium arsenide, indium phosphide, indium antimonide, indium nitride, and combinations thereof. 17. The method of claim 14, wherein the semiconductor layer is gallium nitride. 18. The method of claim 14, wherein the semiconductor layer is aluminum nitride.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>In many developed countries, major portions of the populations consider electronic devices to be integral to their lives. Such increasing use and dependence has generated a demand for electronics devices that are smaller and faster. As electronic circuitry increases in speed and decreases in size, cooling of such devices becomes problematic. Electronic devices generally contain printed circuit boards having integrally connected electronic components that allow the overall functionality of the device. These electronic components, such as processors, transistors, resistors, capacitors, light-emitting diodes (LEDs), etc., generate significant amounts of heat. As it builds, heat can cause various thermal problems associated with such electronic components. Significant amounts of heat can affect the reliability of an electronic device, or even cause it to fail by, for example, causing burn out or shorting both within the electronic components themselves and across the surface of the printed circuit board. Thus, the buildup of heat can ultimately affect the functional life of the electronic device. This is particularly problematic for electronic components with high power and high current demands, as well as for the printed circuit boards that support them. Various cooling devices have been employed such as fans, heat sinks, Peltier and liquid cooling devices, etc., as means of reducing heat buildup in electronic devices. As increased speed and power consumption cause increasing heat buildup, such cooling devices generally must increase in size to be effective and may also require power to operate. For example, fans must be increased in size and speed to increase airflow, and heat sinks must be increased in size to increase heat capacity and surface area. The demand for smaller electronic devices, however, not only precludes increasing the size of such cooling devices, but may also require a significant size decrease. As a result, methods and associated devices are being sought to provide adequate cooling of electronic devices while minimizing size and power constraints placed on such devices due to cooling.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, the present invention provides diamond semiconductor devices having improved thermal properties and methods for making such devices. In one aspect, for example, a semiconductor device is provided having a diamond substrate, a transparent diamond layer positioned parallel to the diamond substrate, and a plurality of semiconductor layers coupled between the transparent diamond layer and the diamond substrate. In one specific aspect, the semiconductor device is an LED device and the plurality of semiconductor layers is a plurality of LED nitride layers. The plurality of semiconductor layers can be arranged in a variety of configuration, however in one aspect the plurality of semiconductor layers may be arranged in series between the diamond substrate and the transparent diamond layer. In various aspects of the present invention, semiconductor devices are provided having very low lattice mismatches between material layers. Such low lattice mismatches may be achieved through the use of a high quality SiC layer. In one aspect, for example, the device may further include a SiC layer coupled to the transparent diamond layer and facing the plurality of semiconductor layers, such that the SiC layer is coupled to at least one of the plurality of semiconductor layers. In another aspect the SiC layer is a single crystal SiC layer. In yet another aspect the SiC layer has a crystal lattice that is substantially epitaxially matched to the transparent diamond layer. In a further aspect, the SiC layer has a crystal lattice that is substantially epitaxially matched to at least one of the semiconductor layers. The devices according to aspects of the present invention also may include various electrodes. In one aspect, for example, the device may include at least one of a p-type electrode or an n-type electrode electrically coupled to at least one of the semiconductor layers. In another aspect, the diamond substrate may be p-type doped, and the p-type electrode is the p-type doped diamond substrate. In one specific aspect, the diamond substrate is doped with boron to form the p-type doped diamond substrate. A variety of semiconductor materials may be used in various aspects the present invention depending on the intended use of resulting devices. For example, and without limitation, the plurality of semiconductor layers may include at least one of silicon germanium, gallium arsenide, gallium nitride, germanium, zinc sulfide, gallium phosphide, gallium antimonide, gallium indium arsenide phosphide, aluminum phosphide, aluminum arsenide, aluminum gallium arsenide, gallium nitride, boron nitride, aluminum nitride, indium arsenide, indium phosphide, indium antimonide, indium nitride, and combinations thereof. In one specific aspect the semiconductor layers may include gallium nitride. In another specific aspect the semiconductor layers may include aluminum nitride. The present invention also provides methods for making semiconductor devices. In one aspect such a method may include forming a transparent diamond layer having a SiC layer coupled thereto, where the SiC layer has a crystal structure that is substantially epitaxially matched to the transparent diamond layer, forming epitaxially a plurality of semiconductor layers on the SiC layer, and coupling a diamond substrate to at least one of the plurality of semiconductor layers such that the diamond support is oriented parallel to the transparent diamond layer. In another aspect such a method may further include electrically coupling at least one of a p-type electrode or an n-type electrode to at least one of the plurality of semiconductor layers. There has thus been outlined, rather broadly, various features of the invention so that the detailed description thereof that follows may be better understood, and so that the present contribution to the art may be better appreciated. Other features of the present invention will become clearer from the following detailed description of the invention, taken with the accompanying claims, or may be learned by the practice of the invention.
|
FIELD OF THE INVENTION The present invention relates generally to semiconductor devices and associated methods. Accordingly, the present invention involves the electrical and material science fields. BACKGROUND OF THE INVENTION In many developed countries, major portions of the populations consider electronic devices to be integral to their lives. Such increasing use and dependence has generated a demand for electronics devices that are smaller and faster. As electronic circuitry increases in speed and decreases in size, cooling of such devices becomes problematic. Electronic devices generally contain printed circuit boards having integrally connected electronic components that allow the overall functionality of the device. These electronic components, such as processors, transistors, resistors, capacitors, light-emitting diodes (LEDs), etc., generate significant amounts of heat. As it builds, heat can cause various thermal problems associated with such electronic components. Significant amounts of heat can affect the reliability of an electronic device, or even cause it to fail by, for example, causing burn out or shorting both within the electronic components themselves and across the surface of the printed circuit board. Thus, the buildup of heat can ultimately affect the functional life of the electronic device. This is particularly problematic for electronic components with high power and high current demands, as well as for the printed circuit boards that support them. Various cooling devices have been employed such as fans, heat sinks, Peltier and liquid cooling devices, etc., as means of reducing heat buildup in electronic devices. As increased speed and power consumption cause increasing heat buildup, such cooling devices generally must increase in size to be effective and may also require power to operate. For example, fans must be increased in size and speed to increase airflow, and heat sinks must be increased in size to increase heat capacity and surface area. The demand for smaller electronic devices, however, not only precludes increasing the size of such cooling devices, but may also require a significant size decrease. As a result, methods and associated devices are being sought to provide adequate cooling of electronic devices while minimizing size and power constraints placed on such devices due to cooling. SUMMARY OF THE INVENTION Accordingly, the present invention provides diamond semiconductor devices having improved thermal properties and methods for making such devices. In one aspect, for example, a semiconductor device is provided having a diamond substrate, a transparent diamond layer positioned parallel to the diamond substrate, and a plurality of semiconductor layers coupled between the transparent diamond layer and the diamond substrate. In one specific aspect, the semiconductor device is an LED device and the plurality of semiconductor layers is a plurality of LED nitride layers. The plurality of semiconductor layers can be arranged in a variety of configuration, however in one aspect the plurality of semiconductor layers may be arranged in series between the diamond substrate and the transparent diamond layer. In various aspects of the present invention, semiconductor devices are provided having very low lattice mismatches between material layers. Such low lattice mismatches may be achieved through the use of a high quality SiC layer. In one aspect, for example, the device may further include a SiC layer coupled to the transparent diamond layer and facing the plurality of semiconductor layers, such that the SiC layer is coupled to at least one of the plurality of semiconductor layers. In another aspect the SiC layer is a single crystal SiC layer. In yet another aspect the SiC layer has a crystal lattice that is substantially epitaxially matched to the transparent diamond layer. In a further aspect, the SiC layer has a crystal lattice that is substantially epitaxially matched to at least one of the semiconductor layers. The devices according to aspects of the present invention also may include various electrodes. In one aspect, for example, the device may include at least one of a p-type electrode or an n-type electrode electrically coupled to at least one of the semiconductor layers. In another aspect, the diamond substrate may be p-type doped, and the p-type electrode is the p-type doped diamond substrate. In one specific aspect, the diamond substrate is doped with boron to form the p-type doped diamond substrate. A variety of semiconductor materials may be used in various aspects the present invention depending on the intended use of resulting devices. For example, and without limitation, the plurality of semiconductor layers may include at least one of silicon germanium, gallium arsenide, gallium nitride, germanium, zinc sulfide, gallium phosphide, gallium antimonide, gallium indium arsenide phosphide, aluminum phosphide, aluminum arsenide, aluminum gallium arsenide, gallium nitride, boron nitride, aluminum nitride, indium arsenide, indium phosphide, indium antimonide, indium nitride, and combinations thereof. In one specific aspect the semiconductor layers may include gallium nitride. In another specific aspect the semiconductor layers may include aluminum nitride. The present invention also provides methods for making semiconductor devices. In one aspect such a method may include forming a transparent diamond layer having a SiC layer coupled thereto, where the SiC layer has a crystal structure that is substantially epitaxially matched to the transparent diamond layer, forming epitaxially a plurality of semiconductor layers on the SiC layer, and coupling a diamond substrate to at least one of the plurality of semiconductor layers such that the diamond support is oriented parallel to the transparent diamond layer. In another aspect such a method may further include electrically coupling at least one of a p-type electrode or an n-type electrode to at least one of the plurality of semiconductor layers. There has thus been outlined, rather broadly, various features of the invention so that the detailed description thereof that follows may be better understood, and so that the present contribution to the art may be better appreciated. Other features of the present invention will become clearer from the following detailed description of the invention, taken with the accompanying claims, or may be learned by the practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-section view of a semiconductor device in accordance with one embodiment of the present invention. FIG. 2 is a cross-section view of a semiconductor device in accordance with one embodiment of the present invention. FIG. 3 is a cross-section view of a semiconductor device being constructed in accordance with one embodiment of the present invention. FIG. 4 is a cross-section view of an LED device in accordance with one embodiment of the present invention. FIG. 5 is a cross-section view of an LED device in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Definitions In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set forth below. The singular forms “a,” “an,” and, “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a heat source” includes reference to one or more of such sources, and reference to “the diamond layer” includes reference to one or more of such layers. The terms “heat transfer,” “heat movement,” and “heat transmission” can be used interchangeably, and refer to the movement of heat from an area of higher temperature to an area of cooler temperature. It is intended that the movement of heat include any mechanism of heat transmission known to one skilled in the art, such as, without limitation, conductive, convective, radiative, etc. As used herein, the term “emitting” refers to the process of moving heat or light from a solid material into the air. As used herein, “light-emitting surface” refers to a surface of a device or object from which light is intentionally emitted. Light may include visible light and light within the ultraviolet spectrum. An example of a light-emitting surface may include, without limitation, a nitride layer of an LED, or of semiconductor layers to be incorporated into an LED, from which light is emitted. As used herein, “vapor deposited” refers to materials which are formed using vapor deposition techniques. “Vapor deposition” refers to a process of forming or depositing materials on a substrate through the vapor phase. Vapor deposition processes can include any process such as, but not limited to, chemical vapor deposition (CVD) and physical vapor deposition (PVD). A wide variety of variations of each vapor deposition method can be performed by those skilled in the art. Examples of vapor deposition methods include hot filament CVD, rf-CVD, laser CVD (LCVD), laser ablation, conformal diamond coating processes, metal-organic CVD (MOCVD), sputtering, thermal evaporation PVD, ionized metal PVD (IMPVD), electron beam PVD (EBPVD), reactive PVD, and the like. As used herein, “chemical vapor deposition,” or “CVD” refers to any method of chemically forming or depositing diamond particles in a vapor form upon a surface. Various CVD techniques are well known in the art. As used herein, “physical vapor deposition,” or “PVD” refers to any method of physically forming or depositing diamond particles in a vapor form upon a surface. Various PVD techniques are well known in the art. As used herein, “diamond” refers to a crystalline structure of carbon atoms bonded to other carbon atoms in a lattice of tetrahedral coordination known as sp3 bonding. Specifically, each carbon atom is surrounded by and bonded to four other carbon atoms, each located on the tip of a regular tetrahedron. Further, the bond length between any two carbon atoms is 1.54 angstroms at ambient temperature conditions, and the angle between any two bonds is 109 degrees, 28 minutes, and 16 seconds although experimental results may vary slightly. The structure and nature of diamond, including its physical and electrical properties are well known in the art. As used herein, “distorted tetrahedral coordination” refers to a tetrahedral bonding configuration of carbon atoms that is irregular, or has deviated from the normal tetrahedron configuration of diamond as described above. Such distortion generally results in lengthening of some bonds and shortening of others, as well as the variation of the bond angles between the bonds. Additionally, the distortion of the tetrahedron alters the characteristics and properties of the carbon to effectively lie between the characteristics of carbon bonded in sp3 configuration (i.e. diamond) and carbon bonded in sp2 configuration (i.e. graphite). One example of material having carbon atoms bonded in distorted tetrahedral bonding is amorphous diamond. As used herein, “diamond-like carbon” refers to a carbonaceous material having carbon atoms as the majority element, with a substantial amount of such carbon atoms bonded in distorted tetrahedral coordination. Diamond-like carbon (DLC) can typically be formed by PVD processes, although CVD or other processes could be used such as vapor deposition processes. Notably, a variety of other elements can be included in the DLC material as either impurities, or as dopants, including without limitation, hydrogen, sulfur, phosphorous, boron, nitrogen, silicon, tungsten, etc. As used herein, “amorphous diamond” refers to a type of diamond-like carbon having carbon atoms as the majority element, with a substantial amount of such carbon atoms bonded in distorted tetrahedral coordination. In one aspect, the amount of carbon in the amorphous diamond can be at least about 90%, with at least about 20% of such carbon being bonded in distorted tetrahedral coordination. Amorphous diamond also has a higher atomic density than that of diamond (176 atoms/cm3). Further, amorphous diamond and diamond materials contract upon melting. As used herein, “adynamic” refers to a type of layer which is unable to independently retain its shape and/or strength. For example, in the absence of a mold or support layer, an adynamic diamond layer will tend to curl or otherwise deform when the mold or support surface is removed. While a number of reasons may contribute to the adynamic properties of a layer, in one aspect, the reason may be the extreme thinness of the layer. As used herein, “growth side,” and “grown surface” may be used interchangeably and refer to the surface of a film or layer which is grows during a CVD process. As used herein, “substrate” refers to a support surface to which various materials can be joined in forming a semiconductor or semiconductor-on-diamond device. The substrate may be any shape, thickness, or material, required in order to achieve a specific result, and includes but is not limited to metals, alloys, ceramics, and mixtures thereof. Further, in some aspects, the substrate may be an existing semiconductor device or wafer, or may be a material which is capable of being joined to a suitable device. As used herein, the term “substantially” refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result. For example, an object that is “substantially” enclosed would mean that the object is either completely enclosed or nearly completely enclosed. The exact allowable degree of deviation from absolute completeness may in some cases depend on the specific context. However, generally speaking the nearness of completion will be so as to have the same overall result as if absolute and total completion were obtained. The use of “substantially” is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result. For example, a composition that is “substantially free of” particles would either completely lack particles, or so nearly completely lack particles that the effect would be the same as if it completely lacked particles. In other words, a composition that is “substantially free of” an ingredient or element may still actually contain such item as long as there is no measurable effect thereof. As used herein, the term “about” is used to provide flexibility to a numerical range endpoint by providing that a given value may be “a little above” or “a little below” the endpoint. As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. Concentrations, amounts, and other numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. As an illustration, a numerical range of “about 1 to about 5” should be interpreted to include not only the explicitly recited values of about 1 to about 5, but also include individual values and sub-ranges within the indicated range. Thus, included in this numerical range are individual values such as 2, 3, and 4 and sub-ranges such as from 1-3, from 2-4, and from 3-5, etc., as well as 1, 2, 3, 4, and 5, individually. This same principle applies to ranges reciting only one numerical value as a minimum or a maximum. Furthermore, such an interpretation should apply regardless of the breadth of the range or the characteristics being described. The Invention The present invention provides semiconductor devices having incorporated diamond layers and methods of making such devices. Semiconductor devices are often challenging to cool, particularly those that emit light. It should be noted that, even though much of the following description is devoted to light emitting devices such as LEDs, the scope of the claims of the present invention should not be limited thereby and that such teachings are equally applicable to other types of semiconductor devices. Much of the heat generated by semiconductor devices tends to build up within the semiconducting layers, thus affecting the efficiency of the device. For example, an LED may consist of a plurality of nitride layers arranged to emit light from a light-emitting surface. As they have become increasingly important in electronics and lighting devices, LEDs continue to be developed that have ever increasing power requirements. This trend of increasing power has created cooling problems for such devices. These cooling problems can be exacerbated by the typically small size of these devices, which may render heat sinks with traditional aluminum heat fins ineffective due to their bulky nature. Additionally, such traditional heat sinks block the emission of light if applied to the light-emitting surface of the LED. Because heat sinks cannot interfere with the function of the nitride layers or the light-emitting surface, they are often located at the junction between the LED and a supporting structure such as a circuit board. Such a heat sink location is relatively remote from the accumulation of much of the heat, namely, the light-emitting surface and the nitride layers. It has been discovered that forming a diamond layer within the LED package allows adequate cooling even at high power, while at the same time maintaining a small LED package size. Additionally, in one aspect the maximum operating wattage of an LED may be exceeded by drawing heat from the semiconductor layers of the LED with a diamond layer in order to operate the LED at an operating wattage that is higher than the maximum operating wattage for that LED. Additionally, in both semiconductor devices that emit light and those that don't, heat may be trapped within the semiconducting layers due to the relatively poor thermal conductivity of materials that often make up these layers. Additionally, crystal lattice mismatches between semiconductive layers slow the conduction of heat, thus facilitating further heat buildup. Semiconductor devices have now been developed incorporating layers of diamond that provide, among other things, improved cooling properties to the device. Such layers of diamond increase the flow of heat laterally through the semiconductor device to thus reduce the amount of heat trapped within the semiconductor layers. This lateral heat transmission may thus effectively improve the thermal properties of many semiconductor devices. Furthermore, devices according to aspects of the present invention have increased lattice matching, thus further improving their thermal cooling properties. Additionally, it should be noted that the beneficial properties provided by diamond layers may extend beyond cooling, and as such, the present scope should not be limited thereto. More effective cooling can be achieved within a semiconductor device if diamond layers can be incorporated close to the semiconducting layers. One barrier to integration concerns the high dielectric properties of diamond materials, particularly those that have substantially single crystal lattice configurations. Optimum cooling conditions may be achieved if the diamond layer is within the conductive pathway of the semiconductor device, however such configurations have been difficult to achieve due to the dielectric properties of diamond. It has now been discovered that a conductive diamond layer can function as an electrode and be coupled to semiconductor layers and thus be within the conductive pathway of the device. Additionally, by utilizing a conductive diamond layer as an electrode, LED devices can be constructed having a linear conductive pathway through the semiconductive layers between the electrodes. Many prior LED devices were constructed such that the conductive pathway from the n-type electrode was at a right angle to the conductive pathway from the p-type electrode. Such an “L” shaped conductive pathway caused electrons and holes to be oriented at right angles to one another, thus reducing the efficiency of the device. The linear conductive pathway according to aspects of the present invention causes electrons and holes to be oriented along the same linear pathway, thus improving the efficiency of the LED device. Furthermore, it has been discovered that locating heat-generating semiconductor layers between layers of diamond materials in a “sandwich-like” configuration greatly improves the thermal cooling of semiconductor devices, particularly high power LEDs. It may be beneficial to utilize at least one of the diamond layers as a conductive diamond layer in some aspects, and as such, a high level of epitaxial lattice matching between the conductive diamond layer and an associated semiconductor layer is preferred. Although there may be thermal cooling benefits to lattice matching all associated diamond layers, diamond layers that are nonconductive do not necessarily require such matching. Accordingly, in one aspect of the present invention, an LED device is provided. As is shown in FIG. 1, such a device may include a diamond substrate 12, a transparent diamond layer 14 positioned parallel to the diamond substrate 12, and a plurality of semiconductor layers 16 coupled between the transparent diamond layer 14 and the diamond substrate 12. Light generated by the semiconductor layers 16 is emitted 15 through the transparent diamond layer 14. A reflective layer 13 may be applied to the diamond substrate 12 to reflect light that is emitted toward the diamond substrate 12 back through the semiconductor layers 16 and the transparent diamond layer 14 to thus improve the efficiency of the LED device. Such a reflective layer may be formed from a variety of reflective materials that are known to those of ordinary skill in the art. One example of such a reflective material would be a layer of chromium metal or other reflective metal. In another aspect, as is shown in FIG. 2, a SiC layer 18 may be coupled to the transparent diamond layer 14 in order to improve the lattice matching between the transparent diamond layer 14 and the semiconductor layers 16. In some aspects the transparent diamond layer may also be conductive, thus functioning as an electrode for the semiconductor device. In such cases, an electrode of opposite polarity may be coupled to the semiconductor layers opposite the transparent conductive diamond layer (not shown). FIG. 3 shows selected steps of a method constructing a semiconductor substrate that may be used to form an LED device according to particular aspects of the present invention. A single crystal Si growth substrate 34 is provided upon which other materials are formed. Although it is not required that the Si growth substrate be single crystal, such a single crystal lattice configuration may facilitate deposition of additional materials with fewer lattice mismatches as compared to a non-single crystal substrate. It may be beneficial to thoroughly clean the Si growth substrate to remove any non-crystalline Si or non-Si particles from the wafer prior to deposition that may affect the lattice mismatch between the Si growth substrate and the layers formed thereon. Any method of cleaning the Si growth substrate would be considered to be within the present scope, however, in one aspect the substrate can be soaked in KOH and ultrasonically cleaned with distilled water. Following cleaning of the Si growth substrate 34, an epitaxial layer of single crystal SiC 32 and an epitaxial transparent diamond layer 36 may be formed thereon, such that the single crystal SiC layer 32 is located between the Si growth substrate 34 and the transparent diamond layer 36. The SiC layer may be formed separately from the diamond layer, or it may be formed as a result of, or in conjunction with, the deposition of the diamond layer. For example, the SiC layer may be formed as a result of a gradation process from Si to diamond, as is described below. Additionally, the SiC layer may be created in vivo by the deposition of an amorphous diamond layer onto the Si growth substrate, as is also described below. Subsequently, a Si layer 38 may be deposited on the transparent diamond layer 36. The Si layer 38 improves the bonding of the Si carrier substrate 42 to the transparent diamond layer 36. The Si carrier substrate 42 has a SiO2 layer for bonding to the Si layer 38. Following the wafer bonding of the Si carrier substrate 42 to the Si layer 38, the Si growth substrate 34 may be removed to expose the SiC layer 32. As has been described, the SiC layer 32 may be used as a growth surface for the deposition of semiconductor materials (not shown). In one aspect, following formation of the LED layers on the SiC layer 32, the Si carrier substrate 42 and the Si layer 38 may be removed to expose the transparent diamond layer 36. The diamond substrate may be coupled to the semiconductor layers as has been described (not shown). Diamond materials have excellent thermal conductivity properties that make them ideal for incorporation into semiconductor devices, such as LEDs. The transfer of heat that is present in the semiconductor device can thus be accelerated from the device through a diamond material. It should be noted that the present invention is not limited as to specific theories of heat transmission. As such, in one aspect the accelerated movement of heat from inside the device can be at least partially due to heat movement into and through a diamond layer. Due to the heat conductive properties of diamond, heat can rapidly spread laterally through the diamond layer and to the edges of a semiconductor device. Heat present around the edges will be more rapidly dissipated into the air or into surrounding structures, such as heat spreaders or device supports. Additionally, diamond layers having a major portion of surface area exposed to air will more rapidly dissipate heat from a device in which such a layer is incorporated. Because the thermal conductivity of diamond is greater than the thermal conductivity of a semiconductor layer or other structure to which it is thermally coupled, a heat sink is established by the diamond layer. As such, heat that builds up in the semiconductor layer is drawn into the diamond layer and spread laterally to be discharged from the device. Such accelerated heat transfer may result in semiconductor devices with much cooler operational temperatures. Additionally, the acceleration of heat transfer not only cools a semiconductor device, but may also reduce the heat load on many electronic components that are spatially located nearby the semiconductor device. In some aspects of the present invention, a portion of a diamond layer may be exposed to the air. Such exposure may be limited to the edges of the layer in some cases, or it may be a larger proportion of surface area, such as would be the case for a diamond layer having one side exposed. In such aspects, the accelerated movement of heat away from a semiconductor layer may be at least partially due to heat movement from the diamond layer to air. For example, a diamond material such as diamond-like carbon (DLC) has exceptional heat emissivity characteristics even at temperatures below 100° C., and as such, may effectively radiate heat directly to the air. Many semiconductor materials that comprise a device conduct heat much better than they emit heat. As such, heat can be conducted through a semiconductor material to a DLC layer, spread laterally through the DLC layer, and subsequently emitted to the air along the edges or other exposed surfaces. Due to the high heat conductive and radiative properties of DLC, heat movement from the DLC layer to air can be greater than heat movement from the semiconductor layer to air. Also, heat movement from the semiconductor device to the DLC layer can be greater than heat movement from the semiconductor device to the air. As such, the layer of DLC can serve to accelerate heat transfer away from the semiconductor layer more rapidly than heat can be transferred through the semiconductor device itself, or from the semiconductor device to the air. As has been suggested, various diamond materials may be utilized to provide accelerated heat transferring properties to a semiconductor device. Non-limiting examples of such diamond materials may include diamond, DLC, amorphous diamond, and combinations thereof. It should be noted, however, that any form of natural or synthetic diamond material that may be utilized to cool a semiconductor device is considered to be within the present scope. It should be understood that the following is a very general discussion of diamond deposition techniques that may or may not apply to a particular diamond layer or application, and that such techniques may vary widely between the various aspects of the present invention. Generally, diamond layers may be formed by any means known, including various vapor deposition techniques. Any number of known vapor deposition techniques may be used to form these diamond layers. The most common vapor deposition techniques include chemical vapor deposition (CVD) and physical vapor deposition (PVD), although any similar method can be used if similar properties and results are obtained. In one aspect, CVD techniques such as hot filament, microwave plasma, oxyacetylene flame, rf-CVD, laser CVD (LCVD), metal-organic CVD (MOCVD), laser ablation, conformal diamond coating processes, and direct current arc techniques may be utilized. Typical CVD techniques use gas reactants to deposit the diamond or diamond-like material in a layer, or film. These gases generally include a small amount (i.e. less than about 5%) of a carbonaceous material, such as methane, diluted in hydrogen. A variety of specific CVD processes, including equipment and conditions, as well as those used for boron nitride layers, are well known to those skilled in the art. In another aspect, PVD techniques such as sputtering, cathodic arc, and thermal evaporation may be utilized. Further, specific deposition conditions may be used in order to adjust the exact type of material to be formed, whether DLC, amorphous diamond, or pure diamond. It should also be noted that many semiconductor devices such as LEDs may be degraded by high temperature. Care may need to be taken to avoid damage during diamond deposition by forming at lower temperatures. For example, if the semiconductor contains InN, deposition temperatures of up to about 600° C. may be used. In the case of GaN, layers may be thermally stable up to about 1000° C. Additionally, preformed layers can be brazed, glued, or otherwise affixed to the semiconductor layer or to a support substrate of the semiconductor device using methods which do not unduly interfere with the heat transference of the diamond layer or the functionality of the device. An optional nucleation enhancing layer can be formed on the growth surface of a substrate in order to improve the quality and deposition time of a diamond layer. Specifically, a diamond layer can be formed by depositing applicable nuclei, such as diamond nuclei, on a diamond growth surface of a substrate and then growing the nuclei into a film or layer using a vapor deposition technique. In one aspect of the present invention, a thin nucleation enhancer layer can be coated upon the substrate to enhance the growth of the diamond layer. Diamond nuclei are then placed upon the nucleation enhancer layer, and the growth of the diamond layer proceeds via CVD. A variety of suitable materials will be recognized by those in skilled in the art which can serve as a nucleation enhancer. In one aspect of the present invention, the nucleation enhancer may be a material selected from the group consisting of metals, metal alloys, metal compounds, carbides, carbide formers, and mixtures thereof. Examples of carbide forming materials may include, without limitation, tungsten (W), tantalum (Ta), titanium (Ti), zirconium (Zr), chromium (Cr), molybdenum (Mo), silicon (Si), and manganese (Mn). Additionally, examples of carbides include tungsten carbide (WC), silicon carbide (SiC), titanium carbide (TiC), zirconium carbide (ZrC), and mixtures thereof among others. The nucleation enhancer layer, when used, is a layer which is thin enough that it does not to adversely affect the thermal transmission properties of the diamond layer. In one aspect, the thickness of the nucleation enhancer layer may be less than about 0.1 micrometers. In another aspect, the thickness may be less than about 10 nanometers. In yet another aspect, the thickness of the nucleation enhancer layer is less than about 5 nanometers. In a further aspect of the invention, the thickness of the nucleation enhancer layer is less than about 3 nanometers. Various methods may be employed to increase the quality of the diamond in the nucleation surface of the diamond layer which is created by vapor deposition techniques. For example, diamond particle quality can be increased by reducing the methane flow rate, and increasing the total gas pressure during the early phase of diamond deposition. Such measures, decrease the decomposition rate of carbon, and increase the concentration of hydrogen atoms. Thus a significantly higher percentage of the carbon will be deposited in a sp3 bonding configuration, and the quality of the diamond nuclei formed is increased. Additionally, the nucleation rate of diamond particles deposited on the growth surface of the substrate or the nucleation enhancer layer may be increased in order to reduce the amount of interstitial space between diamond particles. Examples of ways to increase nucleation rates include, but are not limited to; applying a negative bias in an appropriate amount, often about 100 volts, to the growth surface; polishing the growth surface with a fine diamond paste or powder, which may partially remain on the growth surface; and controlling the composition of the growth surface such as by ion implantation of C, Si, Cr, Mn, Ti, V, Zr, W, Mo, Ta, and the like by PVD or PECVD. PVD processes are typically at lower temperatures than CVD processes and in some cases can be below about 200° C. such as about 150° C. Other methods of increasing diamond nucleation will be readily apparent to those skilled in the art. In one aspect of the present invention, the diamond layer may be formed as a conformal diamond layer. Conformal diamond coating processes can provide a number of advantages over conventional diamond film processes. Conformal diamond coating can be performed on a wide variety of substrates, including non-planar substrates. A growth surface can be pretreated under diamond growth conditions in the absence of a bias to form a carbon film. The diamond growth conditions can be conditions that are conventional CVD deposition conditions for diamond without an applied bias. As a result, a thin carbon film can be formed which is typically less than about 100 angstroms. The pretreatment step can be performed at almost any growth temperature such as from about 200° C. to about 900° C., although lower temperatures below about 500° C. may be preferred. Without being bound to any particular theory, the thin carbon film appears to form within a short time, e.g., less than one hour, and is a hydrogen terminated amorphous carbon. Following formation of the thin carbon film, the growth surface may then be subjected to diamond growth conditions to form a conformal diamond layer. The diamond growth conditions may be those conditions which are commonly used in traditional CVD diamond growth. However, unlike conventional diamond film growth, the diamond film produced using the above pretreatment steps results in a conformal diamond film that typically begins growth substantially over the entire growth surface with substantially no incubation time. In addition, a continuous film, e.g. substantially no grain boundaries, can develop within about 80 nm of growth. Diamond layers having substantially no grain boundaries may move heat more efficiently than those layers having grain boundaries. Various techniques may be employed to render a diamond layer conductive. Such techniques are known to those of ordinary skill in the art. For example, various impurities may be doped into the crystal lattice of the diamond layer. Such impurities may include elements such as Si, B, P, N, Li, Al, Ga, etc. In one specific aspect, for example, the diamond layer may be doped with B. Impurities may also include metallic particles within the crystal lattice, provided they do not interfere with the function of the device, such as by blocking light emitted from an LED. For some diamond layers, particularly those on which semiconductor layers are to be formed, it may be beneficial to create a growth substrate upon which the semiconductor material can be formed with minimal crystal lattice dislocations as a substantially single crystal. Additionally, diamond layers having low crystal lattice dislocations tend to be transparent to light. Minimizing crystal lattice dislocations may be facilitated by utilizing a growth substrate that is substantially a single crystal and has properties such that strong bonding interactions with the semiconductor material may be achieved. In one aspect, such a substrate includes a substantially single crystal diamond layer having a substantially single crystal SiC layer epitaxially coupled thereto. The substantially single crystal nature of the SiC layer facilitates the deposition of a semiconductor such as GaN or AlN as a substantially single crystal. Additionally, the epitaxial relationship from the diamond layer through the SiC layer and to the semiconductor layer increases thermal conduction to the diamond layer, thus improving the cooling properties of the device. Various methods are possible for building such a diamond/SiC composite substrate. Any such method would be considered to be within the scope of the present invention. For example, in one aspect such a substrate may be created by grading a single crystal Si wafer into a single crystal diamond layer. In other words, the Si wafer would gradually transition from Si to SiC and then to diamond. Techniques for such grading are further discussed in the Applicant's copending U.S. patent application entitled “Graded Crystalline Materials And Associated Methods”, and filed on May 31, 2007 under Attorney Docket No. 00802-32733.NP, which is incorporated herein by reference. In addition to the above described benefits of minimizing crystal dislocations, substantially single crystal diamond layers are substantially transparent to light and are thus useful in constructing light-emitting semiconductor devices such as LEDs and laser diodes. The resulting structure includes a substantially single crystal diamond layer having a substantially single crystal SiC layer epitaxially coupled thereto. Semiconductor layers may be epitaxially formed on the SiC layer by any method know to one of ordinary skill in the art. In one aspect such deposition may occur in a graded manner similar to the techniques used in forming the diamond layer on the Si wafer. Following formation of the semiconductor layers, a diamond support may be coupled thereto. Numerous methods of coupling are known to one of ordinary skill in the art, such as brazing, gluing, annealing, etc. It should be noted that any coupling method may be used, provided the functionality of the diamond support is not substantially affected. In one specific aspect, a reflective layer of a carbide forming metal may be applied to a surface of a semiconductor layer. One example of such a metal is titanium. The diamond support may then be formed on the titanium reflective layer and thus coupled to the semiconductive layer by titanium carbide bonds forming between the reflective layer and the diamond substrate. The diamond layers according to aspects of the present invention may be of any thickness that would allow thermal cooling of a semiconductor device. Thicknesses may vary depending on the application and the semiconductor device configuration. For example, greater cooling requirements may require thicker diamond layers. The thickness may also vary depending on the material used in the diamond layer. That being said, in one aspect a diamond layer may be from about 10 to about 50 microns thick. In another example, a diamond layer may be less than or equal to about 10 microns thick. In yet another example, a diamond layer may be from about 50 microns to about 100 microns thick. In a further example, a diamond layer may be greater than about 50 microns thick. In yet a further example, a diamond layer may be an adynamic diamond layer. SiC layers according to aspects of the present invention may have a variety of thicknesses, depending on the method of deposition of the SiC layer and the intended uses of the device. In some aspects the SiC layer may be merely thick enough to orient the crystal lattice of the layers being formed thereon. In other aspects, thicker SiC layers may be beneficial. With such variation in mind, in one aspect the SiC layer may be less than or equal to about 1 micron thick. In another aspect, the SiC layer may be less than or equal to about 500 nanometers thick. In yet another aspect, the SiC layer may be less than or equal to about 1 nanometer thick. In a further aspect, the SiC layer may be greater than about 1 micron thick. As has been described, the semiconductor devices according to aspects of the present invention include a plurality of semiconductor layers associated with one or more diamond layers. These semiconductor layers may be associated with a diamond layer by a variety of methods known to one of ordinary skill in the art. In one aspect of the present invention, however, one or more semiconductor layers may be formed on a diamond layer, or as is described above, on a SiC layer coupled to a diamond layer. A semiconductor layer may be formed on a substrate such as a SiC layer using a variety of techniques known to those of ordinary skill in the art. One example of such a technique is a MOCVD process. The semiconductor layer may include any material that is suitable for forming electronic devices, semiconductor devices, or the like. Many semiconductors are based on silicon, gallium, indium, and germanium. However, suitable materials for the semiconductor layer can include, without limitation, silicon, silicon carbide, silicon germanium, gallium arsenide, gallium nitride, germanium, zinc sulfide, gallium phosphide, gallium antimonide, gallium indium arsenide phosphide, aluminum phosphide, aluminum arsenide, aluminum gallium arsenide, gallium nitride, boron nitride, aluminum nitride, indium arsenide, indium phosphide, indium antimonide, indium nitride, and composites thereof. In one aspect, however, the semiconductor layer can include silicon, silicon carbide, gallium arsenide, gallium nitride, gallium phosphide, aluminum nitride, indium nitride, indium gallium nitride, aluminum gallium nitride, or composites of these materials. In some additional embodiments, non-silicon based devices can be formed such as those based on gallium arsenide, gallium nitride, germanium, boron nitride, aluminum nitride, indium-based materials, and composites thereof. In another embodiment, the semiconductor layer can comprise gallium nitride, indium gallium nitride, indium nitride, and combinations thereof. In one specific aspect, the semiconductor material is gallium nitride. In another specific aspect, the semiconductor material is aluminum nitride. Other semiconductor materials which can be used include Al2O3, BeO, W, Mo, c-Y2O3, c-(Y0.9La0.1)2O3, c-Al23O27N5, c-MgAl2O4, t-MgF2, graphite, and mixtures thereof. It should be understood that the semiconductor layer may include any semiconductor material known, and should not be limited to those materials described herein. Additionally, semiconductor materials may be of any structural configuration known, for example, without limitation, cubic (zincblende or sphalerite), wurtzitic, rhombohedral, graphitic, turbostratic, pyrolytic, hexagonal, amorphous, or combinations thereof. As has been described, the semiconductor layer 14 may be formed by any method known to one of ordinary skill in the art. Various known methods of vapor deposition can be utilized to deposit such layers and that allow deposition to occur in a graded manner. Additionally, surface processing may be performed between any of the deposition steps described in order to provide a smooth surface for subsequent deposition. Such processing may be accomplished by any means known, such as by chemical etching, polishing, buffing, grinding, etc. In one aspect of the present invention, at least one of the semiconductor layers may be gallium nitride (GaN). GaN semiconductor layers may be useful in constructing LEDs and other semiconductor devices. In some cases it may be beneficial to gradually transition between the SiC or other substrate and the semiconductor layer. For example, gradually transitioning an indium nitride (InN) semiconductor substrate into a GaN semiconductor layer may occur by fixing the concentration of the N being vapor deposited and varying the deposited concentration of Ga and of In such that a ratio of Ga:In gradually transitions from about 0:1 to about 1:0. In other words, the sources of Ga and In are varied such that as the In concentration is decreased, the Ga concentration is increased. The gradual transition functions to greatly reduce the lattice mismatch observed when forming GaN directly on InN. In another aspect, at least one of the semiconductor layers may be a layer of aluminum nitride (AlN). The AlN layer may be deposited onto a substrate by any means known to one of ordinary skill in the art. As with the GaN layer described above, gradually transitioning between semiconductor layers may improve the functionality of the semiconductor device. For example, in one aspect AlN may be deposited onto a semiconductor substrate of InN by gradually transitioning the layer of InN into the layer of AlN. Such a gradual transition may include, for example, gradually transitioning the layer of InN into the layer of AlN by fixing the concentration of N being deposited and varying the deposited concentration of In and of Al such that a ratio of In:Al gradually transitions from about 0:1 to about 1:0. Such a gradual transition may greatly reduce the lattice mismatch observed when forming AlN on InN directly. Surface processing may be performed between any of the deposition steps described in order to provide a smooth surface for subsequent deposition. Such processing may be accomplished by any means known, such as by chemical etching, polishing, buffing, grinding, etc. As has been described, electrodes may be incorporated into an LED device as an electrical contact for the semiconductive layers. Various electrodes, particularly p-type and n-type electrodes, including their use and formation, are well known to those of ordinary skill in the art, and will not be discussed in detail herein. In one specific aspect of the present invention as shown in FIG. 4, a “flip-chip” design for an LED device is described. A semiconductor substrate 42 is made as described above and as shown in FIG. 3. An n-type semiconductive material 44 such as n-Gan is formed on the semiconductor substrate 42, followed by the formation of MQW layers 46, and a p-type semiconductor material 48 such as p-GaN. The n-type semiconductive material 44 is electrically coupled to an n-type electrode 50, and the p-type semiconductive material 48 is electrically coupled to a p-type electrode 52. A reflective layer 54 and associated diamond substrate 56 may then be flip-chip bonded to the n-type electrode 50 and the p-type electrode 52. If the reflective layer 54 is conductive it may require division into two electrically isolated portions to facilitate functionality of the device (not shown). As is shown in FIG. 5, in order to emit light the nontransparent layers of the semiconductor substrate need to be removed to expose the transparent diamond layer 58. Upon activation of the LED device, light is generated by the semiconductor layers and emitted 62 through the SiC layer 60 and the transparent diamond layer 58. Additionally, light that is transmitted toward the diamond substrate 56 is reflected by the reflective layer 54 and transmitted back through the semiconductor layers to be emitted through the transparent diamond layer 58. EXAMPLES The following examples illustrate various techniques of making a semiconductor device such as an LED according to aspects of the present invention. However, it is to be understood that the following are only exemplary or illustrative of the application of the principles of the present invention. Numerous modifications and alternative compositions, methods, and systems can be devised by those skilled in the art without departing from the spirit and scope of the present invention. The appended claims are intended to cover such modifications and arrangements. Thus, while the present invention has been described above with particularity, the following Examples provide further detail in connection with several specific embodiments of the invention. Example 1 A semiconductor substrate may be formed as follows: A single crystal Si wafer is obtained and cleaned by soaking in KOH and ultrasound cleaning with distilled water to remove any non-crystalline Si and foreign debris. A conformal amorphous carbon coating is applied to the cleaned surface of the Si wafer by exposing the wafer to CVD deposition conditions without an applied bias. Following carbonization of the surface, amorphous diamond is deposited for approximately 30 minutes at 800° in 1% CH4 and 99% H2. The amorphous carbon coating is then removed with H2 or F2 treatment for about 60 minutes, at 900°. Removal of the amorphous carbon coating exposes an epitaxial SiC layer that has formed in situ between the Si wafer and the amorphous carbon coating. The thickness of the SiC layer is approximately 10 nm. A transparent diamond coating 10 microns thick is then deposited onto the SiC layer by CVD deposition of CH4 for approximately 10 hours. After 10 hours, the CH4 source is then switched to SiH4 for approximately 10 minutes to deposit a 1 micron thick Si layer. A Si carrier substrate having a SiO2 surface is wafer bonded to the 1 micron thick Si layer at the SiO2 surface. Following wafer bonding, the single crystal Si wafer is removed to expose the SiC layer by etching with HF+3HNO2+H2O. Further details regarding etching Si materials may be found in U.S. Pat. No. 4,981,818, which is incorporated herein by reference. Example 2 An LED device may be constructed as follows: A semiconductor substrate is obtained as in Example 1. GaN semiconductor layers are deposited onto the exposed SiC layer by MOCVD with GaH3 and NH3 source materials. Of course, it is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention and the appended claims are intended to cover such modifications and arrangements. Thus, while the present invention has been described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiments of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use may be made without departing from the principles and concepts set forth herein.
|
H
|
H01
|
H01L
|
3103
|
12
|
|||
11712731
|
US20070147048A1-20070628
|
Illumination device
|
ACCEPTED
|
20070613
|
20070628
|
[]
|
F21V700
|
["F21V700"]
|
7635199
|
20070301
|
20091222
|
362
|
235000
|
72228.0
|
LEE
|
GUNYOUNG
|
[{"inventor_name_last": "Guo", "inventor_name_first": "Huang-Chen", "inventor_city": "Junghe", "inventor_state": "", "inventor_country": "TW"}, {"inventor_name_last": "Huang", "inventor_name_first": "Chen-Yuan", "inventor_city": "Junghe", "inventor_state": "", "inventor_country": "TW"}, {"inventor_name_last": "Wang", "inventor_name_first": "Chen-Ming", "inventor_city": "Junghe", "inventor_state": "", "inventor_country": "TW"}, {"inventor_name_last": "Tan", "inventor_name_first": "Tzy-Chang", "inventor_city": "Junghe", "inventor_state": "", "inventor_country": "TW"}, {"inventor_name_last": "Hsieh", "inventor_name_first": "Kun-Han", "inventor_city": "Junghe", "inventor_state": "", "inventor_country": "TW"}, {"inventor_name_last": "Chang", "inventor_name_first": "Kai-Chi", "inventor_city": "Junghe", "inventor_state": "", "inventor_country": "TW"}]
|
The present invention is related to an illumination device capable of producing ambient light and whose structure can be efficiently manufactured and assembled. The illumination device comprises: a substrate electrically connect to a power supply, a plurality of light sources attached to a surface of the substrate, a reflection body with a reflection surface situated a distance from said plurality of light sources, a shell having a diffusion surface situated a distance from said reflection surface. The illumination device may further comprise a housing for receiving and supporting the substrate and the reflection body. The housing is configured to join with the shell and can be further attached to an external device receiving the ambient light. The light emitted from the light sources is reflected by the reflection body to the diffusion member and then radiates outwardly to the surrounding environment of the shell. The reflection surface of the reflection body is inclined at angle relative to the substrate. Said reflection angle formed by the reflection surface and the substrate can be adjusted so that the light is effectively reflected by the reflection surface to the surrounding environment of the device.
|
1. An illumination device, comprising: a substrate; a plurality of light sources attached to a surface of said substrate; a reflection body with a reflection surface situated a distance from said plurality of light sources; a shell having a diffusion member situated a distance from said reflection surface; and wherein said diffusion member comprises a diffusion surface situated a distance away from said reflection surface; and the light emitted from said light sources is reflected by said reflection surface to said diffusion member and then radiates outwardly from said diffusion surface to the surrounding environment of said shell. 2. The illumination device of claim 1, wherein said reflection surface of the reflection body forms an angle with said surface of the substrate. 3. The illumination device of claim 1, wherein said reflection body further comprises a bottom surface parallel to said surface of the substrate such that said bottom surface can be used to attach to said substrate. 4. The illumination device of claim 2, wherein said angle is between 5 degree and 90 degree. 5. The illumination device of claim 1, wherein said shell covers a portion of said substrate and said reflection body. 6. The illumination device of claim 1, wherein said light sources are arranged in equal distance from each other and are aligned longitudinally along the length of said substrate such that uniform lighting is achieved. 7. The illumination device of claim 1, wherein said shell is further provided with at least a slot to allow air circulation such that the temperature inside said shell can be reasonably maintained to avoid over heating of said illumination device. 8. The illumination device of claim 1, wherein said diffusion member is formed integrally with the shell. 9. The illumination device of claim 1 or 3, wherein said reflection body is attached to said substrate via screw fixation. 10. The illumination device of claim 3, wherein an adhesive layer is provided between said bottom surface of the reflection body and said surface of the substrate such that said reflection body is adhesively joined to said substrate. 11. The illumination device of claim 1 or 5, wherein said shell is configured to completely cover said substrate and said reflection body. 12. An illumination device, comprising: a substrate; a plurality of light sources attached to a surface of said substrate; a light reflection shell having a reflection body and a diffusion member arranged a distance from said plurality of light sources; and wherein said reflection body comprises a reflection surface situated a distance from said plurality of light sources, and said diffusion member comprises a diffusion surface situated a distance from said reflection surface; and the light emitted from said light sources is reflected by said reflection body to said diffusion member and then radiates outwardly from said diffusion surface to the surrounding environment of said shell. 13. The illumination device of claim 12, wherein said reflection surface of the reflection body forms an angle with said surface of the substrate. 14. The illumination device of claim 12, wherein said reflection body further comprises a bottom surface parallel to said surface of the substrate such that said bottom surface can be used to attach to said substrate. 15. The illumination device of claim 13, wherein said angle is between 5 degree and 90 degree. 16. The illumination device of claim 12, wherein the light reflection shell covers a portion of said substrate and said reflection body. 17. The illumination device of claim 12, wherein said light sources are arranged in equal distance from each other and are aligned longitudinally along the length of said substrate such that uniform lighting is achieved. 18. The illumination device of claim 12, wherein said light reflection shell is further provided with at least a slot to allowing air circulation such that the temperature inside the shell can be reasonably maintained to avoid over heating of said illumination device. 19. The illumination device of claim 12, wherein said reflection body and said diffusion member are both formed integrally with said light reflection shell. 20. The illumination device of claim 12 or 14, wherein said reflection body is attached to said substrate via screw fixation. 21. The illumination device of claim 14, wherein an adhesive layer is provided between said bottom surface of the reflection body and said surface of the substrate such that said reflection body is adhesively joined to said substrate. 22. The illumination device of claim 12 or 16, wherein said light reflection shell is configured to completely cover said substrate and said reflection body. 23. An illumination device, comprising: a housing; a substrate secured to said housing; a plurality of light sources attached to a surface of said substrate; a reflection body with a reflection surface situated a distance from said plurality of light sources; a shell having a diffusion member situated a distance from said reflection surface and configured to join with said housing; wherein said diffusion member comprises a diffusion surface situated a distance from said reflection surface; and the light emitted from said light sources is reflected by said reflection body to said diffusion member and then radiates outwardly from said diffusion surface to the surrounding environment of said shell and said housing. 24. The illumination device of claim 23, wherein said reflection surface of the reflection body forms an angle with said surface of the substrate. 25. The illumination device of claim 23, wherein said reflection body further comprises a bottom surface parallel to said surface of the substrate such that said bottom surface can be used to attach to said substrate. 26. The illumination device of claim 24, wherein said angle is between 5 degree and 90 degree. 27. The illumination device of claim 23, wherein said housing further comprises at least one securement member to secure said substrate. 28. The illumination device of claim 23, wherein said reflection body is configured to hold said securement members and is secured to said substrate by at least one of said securement members. 29. The illumination device of claim 23, wherein said housing further comprises at least one supporter to support said substrate such that said housing is maintained at a distance from said substrate. 30. The illumination device of claim 23, wherein said shell covers a portion of said housing, said substrate and said reflection body. 31. The illumination device of claim 23, wherein said shell is further provided with at least a slot to allow air circulation such that the temperature inside the shell can be reasonably maintained to avoid over heating of said illumination device. 32. The illumination device of claim 23, wherein said housing is further provided with at least an opening to allow air circulation such that the temperature inside said housing can be reasonably maintained to avoid over heating of said illumination device. 33. The illumination device of claim 23 or 30, wherein said shell is detachably joined to said housing via hook engagement. 34. The illumination device of claim 23, wherein said diffusion member is formed integrally with said shell. 35. The illumination device of claim 23 or 34, wherein said reflection body and said diffusion member are both formed integrally with said shell. 36. The illumination device of claim 27 or 28, wherein said securement member is a screw that can detachably fasten said substrate and said reflection body to said housing. 37. The illumination device of claim 27 or 28, wherein said securement member is a hook that can detachably secure said substrate and said reflection body to said housing. 38. The illumination device of claim 25, wherein an adhesive layer is provided between said bottom surface of the reflection body and said surface of the substrate such that said reflection body is adhesively joined to said substrate. 39. The illumination device of claim 23, wherein said housing is further provided with at least one attachment member that can removably attach said housing to an external device. 40. The external device of claim 39, wherein said external device can be any type of display or audio apparatus. 41. The illumination device of claim 39, wherein said attachment member is a screw that can detachably fasten said housing to said external device. 42. The illumination device of claim 39, wherein said attachment member is a hook that can detachably secure said housing to said external device.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>While it is known that televisions and computer monitors utilize flat panels and digital techniques to improve dimensional size and display quality, more improvements, such as 3D digital comb filters and 3D digital noise reduction, are currently under development. Recently, research and development efforts were made to improve the external environment of the display apparatus by using illumination devices as a means to provide ambient light to the external environment, i.e. the environment surrounding the display apparatus, such as the nearby walls. Ambient light provided by the illumination device to the external environment of a display apparatus can create a comfortable atmosphere for the viewers. The viewers not only can enjoy the images on the display apparatus but also the ambient environment generated by the ambient light from the illumination device. The ambient light can work with the images shown on the display apparatus. For instance, when a video on a television shows a thunderstorm, a dark and lightning effect can be created by the illumination device. More specifically, when lightning is shown on the screen, a flash can be generated by the ambient light to produce the effect of lightning in conjunction with the schemes on the screen. Therefore, the ambient light may be dynamic depending upon the contents shown on the display apparatus. Moreover, sound can also play a significant role in creating different viewing experiences. Ambient light generated by the illumination device can work with sounds to create different viewing experiences for the audience. Another example that demonstrates the need for ambient light is when the screen is small and does not cover the entire wall in front of the viewers. Here, the viewers must concentrate and focus on the small display screen and their eyes need to adjust frequently between the brightness of the image on the display screen and the surrounding environment. The ambient lighting technique can reduce the difference in brightness between the display screen and the surrounding environment such that the stress on viewers' eyes is reduced. U.S. Pat. No. 5,255,171, entitled “Colored Light Source Providing Intensification of Initial Source Illumination”, by L. Douglas Clark discloses an illuminating device utilizing light emitting diodes (“LED”) as light sources and a reflector with parabolic reflecting walls. This illuminating device comprises various LEDs positioned at the base of the reflector and a diffuser attached to the opposite end thereof. However, this prior art primarily focuses on a light concentrator for use with a color optical scanning device, such as a line scanning imaging system or an area scan imaging system. A suitable light source for projecting ambient light is selected based on factors such as: the light transmittance, mixture of different color LEDs, response time of the LEDs, orientation of light projection and the reflectivity of light. Furthermore, one can also physically combine such ambient light sources with a display apparatus or an audio apparatus since audio-video (“AV”) apparatuses are widely available. Most ambient light illumination devices that use LEDs as light source adopt a complex design. For instance, such device may comprise a housing, a substrate or printed circuit board (PCB), a soft layer, a reflection plate, an adhesive layer, a diffusion layer and an external shell. This multi-layer structure makes it difficult to design, manufacture, assembly or maintain the illumination device. For the utilization of the LEDs on the PCB, all the necessary components positioned above the LEDs need to be carefully designed and arranged. Such complex structure can be very costly. In addition, having many separated parts and layers are not desirable since each layer will need to satisfy the conditions of the LEDs used. This may affect the overall performance of the illumination device. The components of the abovementioned illumination devices, in particular the reflection plate, are typically made of metal. However, metal components are subject to oxidation when placed in contact with humidity. Since the inside of the illumination device is not in vacuum, the use of metal is not desirable in the long run. This is particularly true for multi-layered structure since the spaces among the layers can increase contact surface to air and water, thus promoting the oxidation process. Moreover, structure with multiple layers is not preferred when the temperature can rise inside the illumination device. As the LEDs emit light, the internal temperature increases. The design of the illumination device must take into account the rising temperature so that each layer and the structure as a whole can withstand the heat. In view of the above, it is desirable to provide an illumination device that can effectively provide ambient light and can be economically manufactured and maintained. The present invention provides an illumination device with a simplified structure that can facilitate the manufacturing process and can generate and reflect light effectively. The present invention also provides the technical solutions to the deficiencies of the prior illumination device.
|
<SOH> SUMMARY OF THE INVENTION <EOH>One aspect of the invention is to provide an illumination device that can generate ambient light to the surrounding environment. Another aspect of the invention is to provide an illumination device with a structure that can adapt to the changes in operating environment, in particular the temperature and the humidity changes. Another aspect of the invention is to provide an illumination device with a structure that can effectively produce and reflect light and that can be easily assembled so that the overall manufacturing process is simplified and the cost reduced. According to one embodiment of the present invention, an illumination device comprises: a substrate, a plurality of light sources attached to a surface of the substrate, a reflection body with a reflection surface situated a distance from said plurality of light sources, a shell having a diffusion member situated a distance from said reflection surface; wherein the light emitted by the light sources on the substrate travels to the reflection surface of the reflection body upon which the light is reflected to the diffusion member of the shell and then radiate outward through a diffusion surface. A reflection angle is formed by the reflection surface and the substrate. Said reflection angle can be adjusted so that the light is effectively reflected by the reflection surface. This embodiment can be further attached to a housing adapted to hold the abovementioned structure. One of the purposes of the housing is to provide a means for securing the abovementioned components. The housing can also be used as a means for connecting the abovementioned structure to an external device, such as a television or a LCD display screen. According to another embodiment, an illumination device comprises: a substrate, a plurality of light sources attached to a surface of the substrate, and a light reflection shell having a reflection member and a diffusion member situated a distance from said plurality of light sources; wherein said reflection member includes a reflection surface situated a distance from the light sources and said diffusion member includes a diffusion surface situated a distance from the reflection surface so that the light emitted by the light sources are reflected by the reflection surface to the diffusion member and then radiates outwardly from the diffusion surface to the external environment of the shell. The reflection member and the diffusion member are formed integrally with the shell. A reflection angle is formed by the reflection surface and the substrate. Said reflection angle can be adjusted so that the light is effectively reflected by the reflection surface. This embodiment can be further attached to a housing adapted to hold the abovementioned structure. One of the purposes of the housing is to provide a means for securing the abovementioned components. The housing can also be used as a means for connecting the abovementioned structure to an external device, such as a television or a LCD display screen. According to another preferred embodiment of the present invention, an illumination device comprises: a housing, a substrate secured to the housing, a plurality of light sources attached to a surface of the substrate, a reflection body having a reflection surface situated a distance from the light sources, and a shell having a diffusion member situated a distance from the reflection surface such that the light emitted from the light sources is reflected by the reflection surface to the diffusion member and then radiates outwardly from the diffusion surface to the external environment. A reflection angle is formed by the reflection surface and the substrate. Said reflection angle can be adjusted so that the light is effectively reflected and directed by the reflection surface. One of the purposes of said housing is to provide a means for securing the abovementioned components. The housing can also be used to connect the abovementioned structure to an external device, such as a television or a LCD display screen.
|
RELATED APPLICATION This application is a continuation in part of U.S. patent application entitled “Illuminating Device” Ser. No. 11/356,727 filed Feb. 17, 2006, which claims the benefit of the foreign application Taiwan 094221359 filed Dec. 8, 2005. FIELD OF THE INVENTION The present invention relates to an illumination device, and more particularly, to an illumination device capable of providing light emitted from a series of internal light sources and deflects out to an ambient environment. Such illumination device may be used as a backlight for computer monitors, televisions and audio apparatuses. BACKGROUND OF THE INVENTION While it is known that televisions and computer monitors utilize flat panels and digital techniques to improve dimensional size and display quality, more improvements, such as 3D digital comb filters and 3D digital noise reduction, are currently under development. Recently, research and development efforts were made to improve the external environment of the display apparatus by using illumination devices as a means to provide ambient light to the external environment, i.e. the environment surrounding the display apparatus, such as the nearby walls. Ambient light provided by the illumination device to the external environment of a display apparatus can create a comfortable atmosphere for the viewers. The viewers not only can enjoy the images on the display apparatus but also the ambient environment generated by the ambient light from the illumination device. The ambient light can work with the images shown on the display apparatus. For instance, when a video on a television shows a thunderstorm, a dark and lightning effect can be created by the illumination device. More specifically, when lightning is shown on the screen, a flash can be generated by the ambient light to produce the effect of lightning in conjunction with the schemes on the screen. Therefore, the ambient light may be dynamic depending upon the contents shown on the display apparatus. Moreover, sound can also play a significant role in creating different viewing experiences. Ambient light generated by the illumination device can work with sounds to create different viewing experiences for the audience. Another example that demonstrates the need for ambient light is when the screen is small and does not cover the entire wall in front of the viewers. Here, the viewers must concentrate and focus on the small display screen and their eyes need to adjust frequently between the brightness of the image on the display screen and the surrounding environment. The ambient lighting technique can reduce the difference in brightness between the display screen and the surrounding environment such that the stress on viewers' eyes is reduced. U.S. Pat. No. 5,255,171, entitled “Colored Light Source Providing Intensification of Initial Source Illumination”, by L. Douglas Clark discloses an illuminating device utilizing light emitting diodes (“LED”) as light sources and a reflector with parabolic reflecting walls. This illuminating device comprises various LEDs positioned at the base of the reflector and a diffuser attached to the opposite end thereof. However, this prior art primarily focuses on a light concentrator for use with a color optical scanning device, such as a line scanning imaging system or an area scan imaging system. A suitable light source for projecting ambient light is selected based on factors such as: the light transmittance, mixture of different color LEDs, response time of the LEDs, orientation of light projection and the reflectivity of light. Furthermore, one can also physically combine such ambient light sources with a display apparatus or an audio apparatus since audio-video (“AV”) apparatuses are widely available. Most ambient light illumination devices that use LEDs as light source adopt a complex design. For instance, such device may comprise a housing, a substrate or printed circuit board (PCB), a soft layer, a reflection plate, an adhesive layer, a diffusion layer and an external shell. This multi-layer structure makes it difficult to design, manufacture, assembly or maintain the illumination device. For the utilization of the LEDs on the PCB, all the necessary components positioned above the LEDs need to be carefully designed and arranged. Such complex structure can be very costly. In addition, having many separated parts and layers are not desirable since each layer will need to satisfy the conditions of the LEDs used. This may affect the overall performance of the illumination device. The components of the abovementioned illumination devices, in particular the reflection plate, are typically made of metal. However, metal components are subject to oxidation when placed in contact with humidity. Since the inside of the illumination device is not in vacuum, the use of metal is not desirable in the long run. This is particularly true for multi-layered structure since the spaces among the layers can increase contact surface to air and water, thus promoting the oxidation process. Moreover, structure with multiple layers is not preferred when the temperature can rise inside the illumination device. As the LEDs emit light, the internal temperature increases. The design of the illumination device must take into account the rising temperature so that each layer and the structure as a whole can withstand the heat. In view of the above, it is desirable to provide an illumination device that can effectively provide ambient light and can be economically manufactured and maintained. The present invention provides an illumination device with a simplified structure that can facilitate the manufacturing process and can generate and reflect light effectively. The present invention also provides the technical solutions to the deficiencies of the prior illumination device. SUMMARY OF THE INVENTION One aspect of the invention is to provide an illumination device that can generate ambient light to the surrounding environment. Another aspect of the invention is to provide an illumination device with a structure that can adapt to the changes in operating environment, in particular the temperature and the humidity changes. Another aspect of the invention is to provide an illumination device with a structure that can effectively produce and reflect light and that can be easily assembled so that the overall manufacturing process is simplified and the cost reduced. According to one embodiment of the present invention, an illumination device comprises: a substrate, a plurality of light sources attached to a surface of the substrate, a reflection body with a reflection surface situated a distance from said plurality of light sources, a shell having a diffusion member situated a distance from said reflection surface; wherein the light emitted by the light sources on the substrate travels to the reflection surface of the reflection body upon which the light is reflected to the diffusion member of the shell and then radiate outward through a diffusion surface. A reflection angle is formed by the reflection surface and the substrate. Said reflection angle can be adjusted so that the light is effectively reflected by the reflection surface. This embodiment can be further attached to a housing adapted to hold the abovementioned structure. One of the purposes of the housing is to provide a means for securing the abovementioned components. The housing can also be used as a means for connecting the abovementioned structure to an external device, such as a television or a LCD display screen. According to another embodiment, an illumination device comprises: a substrate, a plurality of light sources attached to a surface of the substrate, and a light reflection shell having a reflection member and a diffusion member situated a distance from said plurality of light sources; wherein said reflection member includes a reflection surface situated a distance from the light sources and said diffusion member includes a diffusion surface situated a distance from the reflection surface so that the light emitted by the light sources are reflected by the reflection surface to the diffusion member and then radiates outwardly from the diffusion surface to the external environment of the shell. The reflection member and the diffusion member are formed integrally with the shell. A reflection angle is formed by the reflection surface and the substrate. Said reflection angle can be adjusted so that the light is effectively reflected by the reflection surface. This embodiment can be further attached to a housing adapted to hold the abovementioned structure. One of the purposes of the housing is to provide a means for securing the abovementioned components. The housing can also be used as a means for connecting the abovementioned structure to an external device, such as a television or a LCD display screen. According to another preferred embodiment of the present invention, an illumination device comprises: a housing, a substrate secured to the housing, a plurality of light sources attached to a surface of the substrate, a reflection body having a reflection surface situated a distance from the light sources, and a shell having a diffusion member situated a distance from the reflection surface such that the light emitted from the light sources is reflected by the reflection surface to the diffusion member and then radiates outwardly from the diffusion surface to the external environment. A reflection angle is formed by the reflection surface and the substrate. Said reflection angle can be adjusted so that the light is effectively reflected and directed by the reflection surface. One of the purposes of said housing is to provide a means for securing the abovementioned components. The housing can also be used to connect the abovementioned structure to an external device, such as a television or a LCD display screen. BRIEF DESCRIPTION OF THE DRAWINGS The present invention may be embodied in various forms with reference to the following drawings. The drawings depict only the preferred embodiments of the invention and shall not to be considered as limiting the scope of the present invention. FIG. 1 is an exploded perspective view of a preferred embodiment of the illumination device of the present invention; FIG. 2 is an exploded side elevational view of the illumination device shown in FIG. 1; FIG. 3 is a perspective view of another preferred embodiment of the illumination device; FIG. 4 is a side elevational view of the illumination device shown in FIG. 3; FIG. 5 is an exploded perspective view of another preferred embodiment of the illumination device; and FIG. 6 is an exploded side elevational view of the illumination device shown in FIG. 5. DESCRIPTION OF EMBODIMENTS OF THE INVENTION FIG. 1 and 2 show an exploded perspective view and an exploded side view of an embodiment of the illumination device. As shown in FIG. 1 and 2, one embodiment of an illumination device 10 comprises: a substrate 20, a plurality of light sources 28 attached to a surface 22 of the substrate 20, a reflection body 30 with a reflection surface 32 situated a distance from said plurality of light sources 28, a shell 40 having a diffusion member 42 situated a distance from said reflection surface 32; wherein the diffusion member further comprises a diffusion surface located a distance from the reflection surface 32; and the light emitted from the light sources 28 is reflected by the reflection surface 32 to the diffusion member 42 and then radiates outwardly from the diffusion surface 46 to the external environment of the shell 40. The abovementioned technical features and mechanical structure are described in detailed as follows. First, the ambient light of the illumination device 10 is provided by the light sources 28 attached to a surface 22 of a substrate 20. In one embodiment, the light sources 28 are soldered to said surface 22. The illumination device 10 may further comprise an external power supply (not shown) electrically connected to the substrate 20 to provide the electricity needed by said light sources 28 to generate ambient light. The illumination device 10 may also include data lines (not shown) that can be used to communicate with external apparatus, such as audio or display devices. The light sources can be a light emitted diode (LED) or any other suitable lighting device. The light sources 20 may generate different colors of light, e.g., red, green and blue. One preferred embodiment is to arrange the light sources 28 in equal distance to each other and most preferably, align the light sources longitudinally along the length of the substrate 20 such that uniform lighting can be achieved. Furthermore, the light sources 28 are preferably attached parallel to the flat surface 22 such that the light emitted by the light sources 28 travels upwardly and substantially perpendicular to the substrate 20. The surface 22 of the substrate 20 can be further coated with a nonconductive protection layer resistant to structural deformation caused by external forces or pressure, such as the bombarding of debris or particles. It can also be coated with water-resistance material. A preferred embodiment of the protection layer is a urethane resin or an epoxy resin such that the substrate is resistant to dust, water, heat or deformation. Light emitted by the light sources 28 on the substrate 20 travels upwardly to the reflection surface 32 of the reflection body 30. In one embodiment, the reflection body 30 is at least partially secured to the substrate 20 by means of an attachment to the surface 22 using screws or adhesive joiners. The reflection body 30 comprises a reflection surface 32 and a bottom surface 34. The reflection surface 32 is generally flat and non-transparent and the light traveled thereto is reflected at an angle formed by the reflection body 30 and the substrate 20. As shown in FIG. 2, the bottom surface 34 of the reflection body 30 is generally flat and is attached to the surface 22 of the substrate 20. The reflection surface 32 is inclined at an angle A to reflect the light that travels towards it. An angle B is formed between the reflection surface 32 and the bottom surface 34. In a preferred embodiment, angles A and B are supplementary to each other, i.e. ∠ A+∠ B=180°. Angle A, however, can be set to any degree. In one embodiment, the angle A is between 5° and 90° (or more specifically, 5°≦A<90°). Most preferably, the angle A is 61°. The reflection body 20 can be made of thermoplastic or thermosetting materials of great rigidity and heat resistance, such as ABS, PP, PMMA or the like. The reflection body 20 can also be made of composite materials or metallic materials. In one embodiment, the reflection body 20 is made of thermosetting plastic using injection molding processes. The reflection surface 22 is generally a flat surface with high light reflection coefficient. The coefficient is related to the reflectivity of light from a surface depending on the angle of incidence and the plane of polarization. The reflection body 30 can be attached to the substrate 20 by means of, for example: screw fixation, hook engagement, thermal bonding, press-fit, insertion, adhesive bonding, inserted pin fixation, slidable pin fixation, rotatable pin fixation, soldering, and/or friction press-fitting. In one embodiment, the reflection body 30 is secured to the substrate 20 utilizing nuts and bolts. A bolt through the opening 36 and the hole 26 is joined with a nut such that the reflection body 30 and the substrate 20 are securely attached. In another embodiment, the reflection body 30 is secured to the substrate 20 by screws. A screw that passes through the opening 36 and the hole 26 can be applied to an protrusion or a securement member containing internal threads of a housing. Details relating to the housing are described in the later sections. Once the light reaches the reflection surface 32 and is reflected therefrom, the light travels to a shell 40, in particular to a diffusion member 42 of the shell 40. As shown in FIG. 1 and 2, the diffusion member includes a receiving plane 44 and a diffusion surface 46. When the light hits the receiving plane 44, it is diffused and then radiates outwardly from the diffusion surface 46. In one embodiment, the diffusion member 20 is made of thermosetting plastic and is preferably transparent or semi-transparent with low light reflection coefficient. The diffusion member 42 is preferably formed integrally with the shell 40 by injection molding as an one-piece component. The shell 40 covers at least a portion of the reflection body 30 and the substrate 20 and most preferably, covers the reflection body 30 and the substrate 20 entirely, so that the covered components are adequately protected from dust and/or other external contaminants. The shell 40 may further contain a plurality of slots 48. Preferably, said slots 48 are arranged on the sides of the shell 40. The slots 48 mainly provide air circulation such that the internal temperature of the shell 40 can be reduced and that the substrate 20 and the reflection body 30 are protected from over heat. FIG. 3 and 4 show a second preferred embodiment of the illumination device 110. In this embodiment, the components above the substrate 120 such as the shell 140, reflection member 130 and the diffusion member 142 are formed integrally as an one-piece object—light reflection shell 160. Preferably, the light reflection shell 160 is made of thermoplastic or thermosetting materials, composite materials or metallic materials. In one embodiment, the light reflection shell 160 is made of a thermosetting plastic with high temperature resistance and rigidity and is formed using injection molding processes. The reflection surface 132 has a high light reflection coefficient; whereas the diffusion member 142 has a low light reflection coefficient. In this preferred embodiment, the reflection member 130 is provided with a reflection surface 132 inclined at an angle A′ so that the light emitted from the light sources 122 on the substrate 120 can be reflected. Referring to FIG. 4, the reflection surface 132 and the bottom surface 134 form an angle B′. Preferably, ∠ A′+∠ B′=180°. The angle A′ can be set to any degree. In one embodiment, the angle A′ is between 5° and 90° (or more specifically, 5°≦A′<90°). Most preferably, the angle A′ is 61°. The light that hits the reflection member 130 is reflected by the reflection surface 132 and further travels to the diffusion member 142. As shown in FIG. 3 and 4, said diffusion member 142 is provided with a receiving plane 144 and a diffusion surface 146, wherein the light hits the receiving plane 144 and radiates outwardly from the diffusion surface 146. The light reflection shell 160 can be joined with the substrate 120 by attaching the bottom surface 134 to the surface 122 with, for example: screw fixation, hook engagement, thermal bonding, press-fit, insertion, adhesive bonding, inserted pin fixation, slidable pin fixation, rotatable pin fixation, soldering, and/or friction press-fitting. In one embodiment, the light reflection shell 160 is secured to the substrate 120 utilizing nuts and bolts. A bolt through the opening 136 of the light reflection shell 160 and the hole 126 of the substrate 120 is joined with a nut such that the light reflection shell 160 and the substrate 120 are securely attached. In another embodiment, the light reflection shell 160 is secured to the substrate 120 by screws. A screw that passes through the opening 136 and the hole 126 can be applied to an protrusion or a securement member containing internal threads of a housing. The light reflection shell 160 also includes the diffusion member 142. The light received at the receiving plane 144 is diffused by the diffusion surface and then radiates outwardly therefrom. Preferably, the shell 160 is either transparent or semi-transparent with the diffusion member 142 coated with a medium of low light reflection coefficient to achieve the desired light diffusion. The shell 160 may further contain a plurality of slots 148. The slots 148 are preferably arranged on the sides of the shell 160. The slots 148 provide air circulation such that the internal temperature of the shell 160 is reduced and that the substrate 120 and the reflection member 130 are protected from over heat. The abovementioned embodiments can provide desired ambient light to illuminate surrounding areas. Another preferred embodiment of the present invention is described in detail in the subsequent content with reference to FIG. 5 and 6. This embodiment further comprises a housing 250. The main function of the housing 250 is to provide securement for the various components recited in previous embodiments. A preferred design of the housing 250 is described below but other variations are also available and within the scope of the present invention. Referring to FIG. 5 and 6, a preferred embodiment of the illumination device 210 is illustrated. This embodiment mainly differs from the previous embodiments in that a housing 250 is attached. The housing 250 is used to hold various components in the illumination device and may also be utilized as a base for connecting or attaching to an external device (not shown), such as a display screen. The illumination device 210 comprises a substrate 220, a plurality of light sources 228 on a surface 222, a reflection body 230 that is situated at a distance from said substrate 220 and that has a reflection surface 232 situated a distance from the light sources 228, and a shell 240 with a diffusion surface situated a distance from the reflection surface 232; wherein the light emitted from the light sources 228 reaches the reflection surface 232 and reflected thereupon to a diffusion member 242 and then radiates outwardly to the external environment of the shell 240. The reflection surface 232 of the reflection body 230 forms an angle A″ with the horizontal plane to reflect and direct light. The reflection surface 232 and the bottom surface 234 also form an angle B″. Preferably, ∠ A″+∠ B″=180°. The angle A″ can be set to any degree. In one embodiment, the angle A″ is between 5° and 90° (or more specifically, 5°≦A″<90°). Most preferably, the angle A″ is 61°. The light that hits the reflection body 230 is reflected by the reflection surface 232 and further travels to the diffusion member 242. As shown in FIG. 5 and 6, said diffusion member 242 is provided with a receiving plane 244 and a diffusion surface 246. Light that hits the receiving plane 244 will radiate outwardly from the diffusion surface 246. The housing 250 is preferably arranged beneath the substrate 220, reflection body 230 and the shell 240. As shown in FIG. 5, the housing 250 comprises a plurality of securement members 252 and supports 254. A plurality of through holes 226 are provided on the substrate 220 to correspond to the locations of the securement members 252 on the housing 250 to allow these securement members 252 to pass through. The locations of the through holes 226 are preferably arranged some distant away from the light sources 228. One specific embodiment of the securement members 252 is a plastic protrusion with internal threads to receive screws and is formed integrally with the housing 250. The substrate 220 is secured to the housing 250 via the securement members 252 and is maintained at a distance from the base of the housing 250 by the supports 254. Furthermore, the reflection body 230 is attached to the surface 222 of the substrate 220 and contains at least an opening 236 that corresponds to the position of at least one of the through-holes 226. Preferably, the through-holes 226 on the substrate 220 are aligned with the securement members 252 of housing 250 such that the reflection body 230 and the substrate 220 are attached in conjunction with the housing 250 via attachment means such as screws. The attachment means passes through both the opening 236 and the through-holes 226 and secures itself with at least one of the securement members 252. Via such an efficient attachment, the manufacturing processes can be simplified and made more cost effective. As mentioned previously, the attachment of the components can also be implemented in other ways such as: screw fixation, hook engagement, thermal bonding, press-fit, insertion, adhesive bonding, inserted pin fixation, slidable pin fixation, rotatable pin fixation, soldering and/or friction press-fitting. As shown in FIG. 5 and 6, the edges of the housing 250, in particular the front and rear protruding edges 256, further comprises a plurality of pores 258 to engage the shell 240. The shell 240 preferably covers the housing 250, the substrate 220 and the reflection body 230. A plurality of protrusions (not shown) corresponding to the pores 258 can also be provided at the front and rear edges of the shell 240 for both the positioning and engagement of the shell 240 onto the housing 250. Said engagement can be implemented by means of: screw fixation, hook engagement, thermal bonding, press-fit, insertion, adhesive bonding, inserted pin fixation, slidable pin fixation, rotatable pin fixation, soldering and/or friction press-fitting. The shell 240 may further comprise a plurality of slots 248. Preferably, the slots 248 are located on the sides of the shell 240. The slots 248 can facilitate air circulation such that the heat generated by the light sources 228 inside the shell 240 can be dissipated The housing may further provide a plurality of openings 253 to facilitate air circulation inside the housing 250 so that the heat generated by the light sources can be dissipated properly. The housing 250 may further include an attachment member 255, formed integrally therein and preferably on an external surface of the housing 250, such that the attachment member 255 provides a means of attaching the housing 250 to an external device (not shown), such as a display screen. While the present invention is disclosed by reference to the embodiments detailed herein, note that these examples are intended in an illustrative rather than in a limiting sense. It is contemplated that other modifications and combinations will readily occur to those skilled in the art and will be within the spirit of the invention and the scope of the following claims.
|
F
|
F21
|
F21V
|
7
|
00
|
|||
11678925
|
US20070202848A1-20070830
|
AUTHENTICATION VECTOR GENERATING DEVICE, SUBSCRIBER AUTHENTICATION MODULE, MOBILE COMMUNICATION SYSTEM, AND AUTHENTICATION VECTOR GENERATION METHOD
|
ACCEPTED
|
20070816
|
20070830
|
[]
|
H04M166
|
["H04M166"]
|
7974603
|
20070226
|
20110705
|
455
|
411000
|
64856.0
|
DOAN
|
KIET
|
[{"inventor_name_last": "ISHIKAWA", "inventor_name_first": "Hidetoshi", "inventor_city": "Yokohama-shi", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Shiro", "inventor_name_first": "Teruaki", "inventor_city": "Tokyo", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Umeno", "inventor_name_first": "Hiroshi", "inventor_city": "Tokyo", "inventor_state": "", "inventor_country": "JP"}]
|
To stop functions of a subscriber authentication module regardless of whether a roaming network is based on IMT-2000 or GSM. HLR of a mobile communication network based on IMT-2000 has a stop information addition part instructing a RAND field of an authentication vector used for authentication of USIM to cause part or all of functions in the subscriber authentication module to stop. The USIM mounted in a mobile terminal has a function stop part executing to cause part or all of functions of the subscriber authentication module to stop, an identification part that refers to information identifying stop information contained in received data and transmits the stop information to a function stop part, and an operation part for performing a predetermined operation using the received data.
|
1. An authentication vector generating device for generating an authentication vector including a RAND field in response to a request from an authentication device for authenticating a subscriber authentication module and transmitting the generated authentication vector to the authentication device; comprising: a setting unit for making a setting to an effect that part or all of functions of the subscriber authentication module mounted in a subscriber terminal equipment should be caused to stop based on settings of an operator operating the authentication vector generating device; a request accepting unit for accepting an issue request of an authentication vector for authenticating the subscriber authentication module via the subscriber terminal equipment; an authentication vector generating unit for generating an authentication vector for authenticating the subscriber authentication module mounted in the subscriber terminal equipment after an issue request of an authentication vector is accepted by the request accepting unit; an addition unit for adding stop information instructing to cause part or all of functions of the subscriber authentication module to stop to the RAND field of the authentication vector generated by the authentication vector generating unit when the setting unit makes a setting to the effect that the functions of the subscriber authentication module should be caused to stop; and an authentication vector transmitting unit for transmitting the authentication vector to which the stop information is added by the addition unit to the authentication device. 2. A subscriber authentication module to be mounted in a subscriber terminal equipment; comprising: a stop information receiving unit for receiving stop information for causing part or all of functions of the subscriber authentication module to stop, included in a RAND field of an authentication vector used for authenticating the subscriber authentication module of a mobile communication network; and a stopping unit for stopping part or all of functions in the subscriber authentication module based on the stop information received by the stop information receiving unit. 3. A mobile communication system comprising an authentication device for authenticating a subscriber authentication module, an authentication vector generating device for generating an authentication vector including a RAND field in response to a request from the authentication device and transmitting the generated authentication vector to the authentication device, and the subscriber authentication module mounted in a subscriber terminal equipment, wherein the authentication vector generating device; includes: a setting unit for making a setting to an effect that part or all of functions of the subscriber authentication module mounted in the subscriber terminal equipment should be caused to stop based on settings of an operator operating the authentication vector generating device; a request accepting unit for accepting an issue request of an authentication vector from the authentication device for authenticating the subscriber authentication module via the subscriber terminal equipment set by the setting unit; an authentication vector generating unit for generating an authentication vector for authenticating the subscriber authentication module mounted in the subscriber terminal equipment after an issue request of an authentication vector is accepted by the request accepting unit; an addition unit for adding stop information instructing to cause part or all of functions of the subscriber authentication module to stop to the RAND field of the authentication vector generated by the authentication vector generating unit when the setting unit makes a setting to the effect that the functions of the subscriber authentication module should be caused to stop; and an authentication vector transmitting unit for transmitting the authentication vector to which the stop information is added by the addition unit to the authentication device, and wherein the subscriber authentication module; includes: a stop information receiving unit for receiving stop information included in the RAND field of the authentication vector transmitted by the authentication vector transmitting unit; and a stopping unit for stopping part or all of functions in the subscriber authentication module based on the stop information received by the stop information receiving unit. 4. A method of generating an authentication vector of an authentication vector generating device that generates an authentication vector including a RAND field in response to a request from an authentication device authenticating a subscriber authentication module and transmits the generated authentication vector to the authentication device; comprising: a setting step of making a setting to an effect that part or all of functions of the subscriber authentication module mounted in the subscriber terminal equipment should be caused to stop based on settings of an operator operating the authentication vector generating device; an accepting step of accepting an issue request of an authentication vector from the authentication device for authenticating the subscriber authentication module via the subscriber terminal equipment set by the setting step; an authentication vector generating step of generating an authentication vector for authenticating the subscriber authentication module in the subscriber terminal equipment after a request of the authentication vector is accepted by the accepting step; an addition step of adding stop information instructing to cause part or all of functions of the subscriber authentication module to stop to the RAND field of the authentication vector generated by the authentication vector generating step when the setting step makes a setting to the effect that the functions of the subscriber authentication module should be caused to stop; and a transmitting step of transmitting the authentication vector to which the stop information is added by the addition step to the authentication device.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to an authentication vector generating device for causing functions of a subscriber authentication module to stop, the subscriber authentication module, a mobile communication system and an authentication vector generation method. 2. Related Background of the Invention In recent years, public opinion about protection of personal information is on the rise such as establishment of laws relating to protection of personal information. Mobile communication businesses, on the other hand, have several dozens of millions of subscribers and are now quite familiar in everyday life. A subscriber authentication module used and managed by a user in mobile communication and a mobile phone in which the subscriber authentication module is mounted are devices containing a lot of personal information and are carried by the user at normal times, and thus it is not rare that such devices become non-controllable by the user due to a loss or theft. If the subscriber authentication module or the mobile phone in which the subscriber authentication module is mounted is lost or stolen, stopping calls or communication using the subscriber authentication module can quickly be dealt with only by reporting to a mobile communication operator to which the subscriber of the mobile communication network subscribes or an issuer of subscriber authentication module (hereinafter, the mobile communication network provided as a service by the mobile communication operator or the issuer of subscriber authentication module is called a “home network”). However, utilization stop of communication lines using the subscriber authentication module means only that call connection by network equipment in a home network is not established and can not stop functions of the subscriber authentication module itself mounted in a mobile phone. Here, as a mechanism to cause functions of a subscriber authentication module itself to stop, that is, to prevent utilization by a user other than a legitimate user, there is a function to authenticate a legitimate user of the subscriber authentication module by forcing input of PIN (Personal Identity Number) into the subscriber authentication module for verification. That is, authenticating a legitimate user of the subscriber authentication module by input of PIN by a user during power-on (that is, starting power supply to the subscriber authentication module) of a mobile terminal is considered. As long as PIN is not known to third parties, the PIN of the subscriber authentication module cannot be made verified in the authentication function based on the PIN. Thus, for example, when the subscriber authentication module is inserted into another mobile phone and power supply to the subscriber authentication module is once cut, then it will be impossible to access internal information that requires PIN verification in the subscriber authentication module to which power is again supplied. Patent Document 1 shown below relates to a function stop method of causing various functions of a mobile terminal unit to stop easily and reliably by a third party when the mobile terminal unit is stolen or lost and describes a method to cause various functions of the mobile terminal unit to stop by transmitting an e-mail to the stolen or lost mobile terminal unit. [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-209260
|
<SOH> SUMMARY OF THE INVENTION <EOH>However, once legitimate information is input for PIN verification of a subscriber authentication module (hereinafter a verified state is assumed), thereafter the verified state will be maintained until the subscriber authentication module is turned off or reset (restarted). If a mobile phone in which a subscriber authentication module is mounted is lost, it is usually assumed that PIN of the subscriber authentication module was verified at least when a legitimate user managed the mobile phone. Therefore, the PIN verified state of the subscriber authentication module can be maintained unless power supply is interrupted using a device (charger) conforming to the mobile phone after the mobile phone is taken back, and in this case, information stored in the subscriber authentication module can be accessed. By inputting and setting the PIN, the legitimate user can also disable a PIN verification function itself for the subscriber authentication module in advance. That is, if the PIN verification function is disabled in the subscriber authentication module, it is quite easy to view internally stored information by removing the subscriber authentication module from the taken-back mobile phone to insert it into another mobile phone or connecting an IC card reader/writer to a personal computer. Since the above-described method of Patent Document 1 requires an e-mail function, it is difficult to apply the method to all mobile terminal units. Further, if the mobile terminal is located at the place where no e-mail can be received, for example, no radio wave is received, the function cannot be executed and, even after moving to a place where radio waves can be received, the functions of the mobile terminal cannot be quickly caused to stop because an e-mail may not be received immediately. Therefore, in order to solve the above problems, an object of the present invention is to provide an authentication vector generating device that can cause part or all of functions of a subscriber authentication module to stop quickly, the subscriber authentication module, a mobile communication system, and an authentication vector generation method. An authentication vector generating device in the present invention is one for generating an authentication vector which includes a RAND field in response to a request from an authentication device for authenticating a subscriber authentication module and transmitting the generated authentication vector to the authentication device; and comprises: a setting unit for making a setting to an effect that part or all of functions of the subscriber authentication module mounted in a subscriber terminal equipment should be caused to stop based on settings of an operator operating the authentication vector generating device; a request accepting unit for accepting an issue request of an authentication vector for authenticating the subscriber authentication module via the subscriber terminal equipment; an authentication vector generating unit for generating an authentication vector for authenticating the subscriber authentication module mounted in the subscriber terminal equipment after an issue request of an authentication vector is accepted by the request accepting unit; an addition unit for adding stop information instructing to cause part or all of functions of the subscriber authentication module to stop to the RAND field of the authentication vector generated by the authentication vector generating unit when the setting unit makes a setting to the effect that the functions of the subscriber authentication module should be caused to stop; and an authentication vector transmitting unit for transmitting the authentication vector to which the stop information is added by the addition unit to the authentication device. An authentication vector generation method in the present invention is a method of generating an authentication vector of an authentication vector generating device that generates an authentication vector including a RAND field in response to a request from an authentication device authenticating a subscriber authentication module and transmits the generated authentication vector to the authentication device; and the method comprises: a setting step of making a setting to an effect that part or all of functions of the subscriber authentication module mounted in the subscriber terminal equipment should be caused to stop based on settings of an operator operating the authentication vector generating device; an accepting step of accepting an issue request of an authentication vector from the authentication device for authenticating the subscriber authentication module via the subscriber terminal equipment set by the setting step; an authentication vector generating step of generating an authentication vector for authenticating the subscriber authentication module in the subscriber terminal equipment after a request of the authentication vector is accepted by the accepting step; an addition step of adding stop information instructing to cause part or all of functions of the subscriber authentication module to stop to the RAND field of the authentication vector generated by the authentication vector generating step when the setting step makes a setting to the effect that the functions of the subscriber authentication module should be caused to stop; and a transmitting step of transmitting the authentication vector to which the stop information is added by the addition step to the authentication device. According to the present invention, if a setting is made to an effect that part or all of functions of a subscriber authentication module mounted in subscriber terminal equipment should be caused to stop based on settings of an operator operating an authentication vector generating device or a user of the subscriber terminal equipment and an issue request of an authentication vector from an authentication device whose location registration has been performed from the set subscriber terminal equipment is accepted, an authentication vector for authenticating the subscriber authentication module in the subscriber terminal equipment is generated. Then, if a setting is made to stop the functions of the subscriber authentication module, stop information instructing to cause part or all of functions of the subscriber authentication module to stop is added to the RAND field of the generated authentication vector so that the authentication vector to which the stop information is added can be transmitted to the authentication device. An authentication vector for stopping functions is thereby generated in accordance with a location registration request from the subscriber terminal equipment such as a mobile terminal and, therefore, the functions can be quickly stopped when the subscriber terminal equipment is located where radio waves are received. Further, since stop information is added to the RAND field in the authentication vector, information for stopping can reliably be transmitted to the subscriber terminal equipment without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM (Global System for Mobile Communications) and that based on IMT (International Mobile Telecommunication)-2000 due, for example, to roaming. A subscriber authentication module in the present invention is one to be mounted in a subscriber terminal equipment, and comprises: a stop information receiving unit for receiving stop information for causing part or all of functions of the subscriber authentication module to stop included in a RAND field of an authentication vector used for authenticating the subscriber authentication module of a mobile communication network; and a stopping unit for stopping part or all of functions in the subscriber authentication module based on the stop information received by the stop information receiving unit. According to the present invention, part or all of functions of a subscriber authentication module can be caused to stop based on stop information after receiving the stop information for causing part or all of functions of the subscriber authentication module, the stop information being written in the RAND field of an authentication vector. Functions set in the authentication vector can thereby be quickly stopped in the subscriber terminal equipment if a location registration request can be made, that is, if the subscriber terminal equipment is located where radio waves are received. Also, function stop processing can be performed based on the stop information for stopping the functions set to the RAND field of the authentication vector and the stop information can reliably be extracted to stop the functions without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM (Global System for Mobile Communications) and that based on IMT (International Mobile Telecommunication)-2000 due, for example, to roaming. A mobile communication system in the present invention is one that comprises an authentication device for authenticating a subscriber authentication module, an authentication vector generating device for generating an authentication vector including a RAND field in response to a request from the authentication device and transmitting the generated authentication vector to the authentication device, and the subscriber authentication module mounted in a subscriber terminal equipment, wherein the authentication vector generating device; includes: a setting unit for making a setting to an effect that part or all of functions of the subscriber authentication module mounted in the subscriber terminal equipment should be caused to stop based on settings of an operator operating the authentication vector generating device; a request accepting unit for accepting an issue request of an authentication vector from the authentication device for authenticating the subscriber authentication module via the subscriber terminal equipment set by the setting unit; an authentication vector generating unit for generating an authentication vector for authenticating the subscriber authentication module mounted in the subscriber terminal equipment after an issue request of an authentication vector is accepted by the request accepting unit; an addition unit for adding stop information instructing to cause part or all of functions of the subscriber authentication module to stop to the RAND field of the authentication vector generated by the authentication vector generating unit when the setting unit makes a setting to the effect that the functions of the subscriber authentication module should be caused to stop; and an authentication vector transmitting unit for transmitting the authentication vector to which the stop information is added by the addition unit to the authentication device, and wherein the subscriber authentication module; includes: a stop information receiving unit for receiving stop information included in the RAND field of the authentication vector transmitted by the authentication vector transmitting unit; and a stopping unit for stopping part or all of functions in the subscriber authentication module based on the stop information received by the stop information receiving unit. An authentication vector is thereby generated quickly in accordance with a location registration request from a subscriber terminal equipment such as a mobile terminal and, therefore, the functions can quickly be caused to stop if the subscriber terminal equipment is located where radio waves are received. Further, since the stop information is added to the RAND field in the authentication vector, information for stopping the functions can reliably be transmitted to the subscriber terminal equipment without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM and that based on IMT-2000 due, for example, to roaming. Functions set in an authentication vector can be quickly stopped in the subscriber terminal equipment if a location registration request can be made, that is, if the subscriber terminal equipment is located where radio waves are received. Also, function stop processing can be performed based on the stop information for stopping the functions set to the RAND field of the authentication vector and information for stopping can reliably be extracted to stop the functions without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM (Global System for Mobile Communications) and that based on IMT (International Mobile Telecommunication)-2000 due, for example, to roaming. According to the present invention, when subscriber terminal equipment is located where radio waves are received, functions thereof can quickly be caused to stop. If a subscriber module is mounted in the subscriber terminal equipment, functions thereof can quickly be stopped based on an authentication vector. BRFSUM description="Brief Summary" end="tail"?
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an authentication vector generating device for causing functions of a subscriber authentication module to stop, the subscriber authentication module, a mobile communication system and an authentication vector generation method. 2. Related Background of the Invention In recent years, public opinion about protection of personal information is on the rise such as establishment of laws relating to protection of personal information. Mobile communication businesses, on the other hand, have several dozens of millions of subscribers and are now quite familiar in everyday life. A subscriber authentication module used and managed by a user in mobile communication and a mobile phone in which the subscriber authentication module is mounted are devices containing a lot of personal information and are carried by the user at normal times, and thus it is not rare that such devices become non-controllable by the user due to a loss or theft. If the subscriber authentication module or the mobile phone in which the subscriber authentication module is mounted is lost or stolen, stopping calls or communication using the subscriber authentication module can quickly be dealt with only by reporting to a mobile communication operator to which the subscriber of the mobile communication network subscribes or an issuer of subscriber authentication module (hereinafter, the mobile communication network provided as a service by the mobile communication operator or the issuer of subscriber authentication module is called a “home network”). However, utilization stop of communication lines using the subscriber authentication module means only that call connection by network equipment in a home network is not established and can not stop functions of the subscriber authentication module itself mounted in a mobile phone. Here, as a mechanism to cause functions of a subscriber authentication module itself to stop, that is, to prevent utilization by a user other than a legitimate user, there is a function to authenticate a legitimate user of the subscriber authentication module by forcing input of PIN (Personal Identity Number) into the subscriber authentication module for verification. That is, authenticating a legitimate user of the subscriber authentication module by input of PIN by a user during power-on (that is, starting power supply to the subscriber authentication module) of a mobile terminal is considered. As long as PIN is not known to third parties, the PIN of the subscriber authentication module cannot be made verified in the authentication function based on the PIN. Thus, for example, when the subscriber authentication module is inserted into another mobile phone and power supply to the subscriber authentication module is once cut, then it will be impossible to access internal information that requires PIN verification in the subscriber authentication module to which power is again supplied. Patent Document 1 shown below relates to a function stop method of causing various functions of a mobile terminal unit to stop easily and reliably by a third party when the mobile terminal unit is stolen or lost and describes a method to cause various functions of the mobile terminal unit to stop by transmitting an e-mail to the stolen or lost mobile terminal unit. [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-209260 SUMMARY OF THE INVENTION However, once legitimate information is input for PIN verification of a subscriber authentication module (hereinafter a verified state is assumed), thereafter the verified state will be maintained until the subscriber authentication module is turned off or reset (restarted). If a mobile phone in which a subscriber authentication module is mounted is lost, it is usually assumed that PIN of the subscriber authentication module was verified at least when a legitimate user managed the mobile phone. Therefore, the PIN verified state of the subscriber authentication module can be maintained unless power supply is interrupted using a device (charger) conforming to the mobile phone after the mobile phone is taken back, and in this case, information stored in the subscriber authentication module can be accessed. By inputting and setting the PIN, the legitimate user can also disable a PIN verification function itself for the subscriber authentication module in advance. That is, if the PIN verification function is disabled in the subscriber authentication module, it is quite easy to view internally stored information by removing the subscriber authentication module from the taken-back mobile phone to insert it into another mobile phone or connecting an IC card reader/writer to a personal computer. Since the above-described method of Patent Document 1 requires an e-mail function, it is difficult to apply the method to all mobile terminal units. Further, if the mobile terminal is located at the place where no e-mail can be received, for example, no radio wave is received, the function cannot be executed and, even after moving to a place where radio waves can be received, the functions of the mobile terminal cannot be quickly caused to stop because an e-mail may not be received immediately. Therefore, in order to solve the above problems, an object of the present invention is to provide an authentication vector generating device that can cause part or all of functions of a subscriber authentication module to stop quickly, the subscriber authentication module, a mobile communication system, and an authentication vector generation method. An authentication vector generating device in the present invention is one for generating an authentication vector which includes a RAND field in response to a request from an authentication device for authenticating a subscriber authentication module and transmitting the generated authentication vector to the authentication device; and comprises: a setting unit for making a setting to an effect that part or all of functions of the subscriber authentication module mounted in a subscriber terminal equipment should be caused to stop based on settings of an operator operating the authentication vector generating device; a request accepting unit for accepting an issue request of an authentication vector for authenticating the subscriber authentication module via the subscriber terminal equipment; an authentication vector generating unit for generating an authentication vector for authenticating the subscriber authentication module mounted in the subscriber terminal equipment after an issue request of an authentication vector is accepted by the request accepting unit; an addition unit for adding stop information instructing to cause part or all of functions of the subscriber authentication module to stop to the RAND field of the authentication vector generated by the authentication vector generating unit when the setting unit makes a setting to the effect that the functions of the subscriber authentication module should be caused to stop; and an authentication vector transmitting unit for transmitting the authentication vector to which the stop information is added by the addition unit to the authentication device. An authentication vector generation method in the present invention is a method of generating an authentication vector of an authentication vector generating device that generates an authentication vector including a RAND field in response to a request from an authentication device authenticating a subscriber authentication module and transmits the generated authentication vector to the authentication device; and the method comprises: a setting step of making a setting to an effect that part or all of functions of the subscriber authentication module mounted in the subscriber terminal equipment should be caused to stop based on settings of an operator operating the authentication vector generating device; an accepting step of accepting an issue request of an authentication vector from the authentication device for authenticating the subscriber authentication module via the subscriber terminal equipment set by the setting step; an authentication vector generating step of generating an authentication vector for authenticating the subscriber authentication module in the subscriber terminal equipment after a request of the authentication vector is accepted by the accepting step; an addition step of adding stop information instructing to cause part or all of functions of the subscriber authentication module to stop to the RAND field of the authentication vector generated by the authentication vector generating step when the setting step makes a setting to the effect that the functions of the subscriber authentication module should be caused to stop; and a transmitting step of transmitting the authentication vector to which the stop information is added by the addition step to the authentication device. According to the present invention, if a setting is made to an effect that part or all of functions of a subscriber authentication module mounted in subscriber terminal equipment should be caused to stop based on settings of an operator operating an authentication vector generating device or a user of the subscriber terminal equipment and an issue request of an authentication vector from an authentication device whose location registration has been performed from the set subscriber terminal equipment is accepted, an authentication vector for authenticating the subscriber authentication module in the subscriber terminal equipment is generated. Then, if a setting is made to stop the functions of the subscriber authentication module, stop information instructing to cause part or all of functions of the subscriber authentication module to stop is added to the RAND field of the generated authentication vector so that the authentication vector to which the stop information is added can be transmitted to the authentication device. An authentication vector for stopping functions is thereby generated in accordance with a location registration request from the subscriber terminal equipment such as a mobile terminal and, therefore, the functions can be quickly stopped when the subscriber terminal equipment is located where radio waves are received. Further, since stop information is added to the RAND field in the authentication vector, information for stopping can reliably be transmitted to the subscriber terminal equipment without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM (Global System for Mobile Communications) and that based on IMT (International Mobile Telecommunication)-2000 due, for example, to roaming. A subscriber authentication module in the present invention is one to be mounted in a subscriber terminal equipment, and comprises: a stop information receiving unit for receiving stop information for causing part or all of functions of the subscriber authentication module to stop included in a RAND field of an authentication vector used for authenticating the subscriber authentication module of a mobile communication network; and a stopping unit for stopping part or all of functions in the subscriber authentication module based on the stop information received by the stop information receiving unit. According to the present invention, part or all of functions of a subscriber authentication module can be caused to stop based on stop information after receiving the stop information for causing part or all of functions of the subscriber authentication module, the stop information being written in the RAND field of an authentication vector. Functions set in the authentication vector can thereby be quickly stopped in the subscriber terminal equipment if a location registration request can be made, that is, if the subscriber terminal equipment is located where radio waves are received. Also, function stop processing can be performed based on the stop information for stopping the functions set to the RAND field of the authentication vector and the stop information can reliably be extracted to stop the functions without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM (Global System for Mobile Communications) and that based on IMT (International Mobile Telecommunication)-2000 due, for example, to roaming. A mobile communication system in the present invention is one that comprises an authentication device for authenticating a subscriber authentication module, an authentication vector generating device for generating an authentication vector including a RAND field in response to a request from the authentication device and transmitting the generated authentication vector to the authentication device, and the subscriber authentication module mounted in a subscriber terminal equipment, wherein the authentication vector generating device; includes: a setting unit for making a setting to an effect that part or all of functions of the subscriber authentication module mounted in the subscriber terminal equipment should be caused to stop based on settings of an operator operating the authentication vector generating device; a request accepting unit for accepting an issue request of an authentication vector from the authentication device for authenticating the subscriber authentication module via the subscriber terminal equipment set by the setting unit; an authentication vector generating unit for generating an authentication vector for authenticating the subscriber authentication module mounted in the subscriber terminal equipment after an issue request of an authentication vector is accepted by the request accepting unit; an addition unit for adding stop information instructing to cause part or all of functions of the subscriber authentication module to stop to the RAND field of the authentication vector generated by the authentication vector generating unit when the setting unit makes a setting to the effect that the functions of the subscriber authentication module should be caused to stop; and an authentication vector transmitting unit for transmitting the authentication vector to which the stop information is added by the addition unit to the authentication device, and wherein the subscriber authentication module; includes: a stop information receiving unit for receiving stop information included in the RAND field of the authentication vector transmitted by the authentication vector transmitting unit; and a stopping unit for stopping part or all of functions in the subscriber authentication module based on the stop information received by the stop information receiving unit. An authentication vector is thereby generated quickly in accordance with a location registration request from a subscriber terminal equipment such as a mobile terminal and, therefore, the functions can quickly be caused to stop if the subscriber terminal equipment is located where radio waves are received. Further, since the stop information is added to the RAND field in the authentication vector, information for stopping the functions can reliably be transmitted to the subscriber terminal equipment without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM and that based on IMT-2000 due, for example, to roaming. Functions set in an authentication vector can be quickly stopped in the subscriber terminal equipment if a location registration request can be made, that is, if the subscriber terminal equipment is located where radio waves are received. Also, function stop processing can be performed based on the stop information for stopping the functions set to the RAND field of the authentication vector and information for stopping can reliably be extracted to stop the functions without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM (Global System for Mobile Communications) and that based on IMT (International Mobile Telecommunication)-2000 due, for example, to roaming. According to the present invention, when subscriber terminal equipment is located where radio waves are received, functions thereof can quickly be caused to stop. If a subscriber module is mounted in the subscriber terminal equipment, functions thereof can quickly be stopped based on an authentication vector. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a configuration of a mobile communication system according to the present embodiment. FIG. 2 is a hardware block diagram of HLR 10. FIG. 3 is a diagram illustrating the configuration of a quintet and a triplet and conversion from the quintet to the triplet. FIG. 4 is a sequence diagram illustrating processing performed in the mobile communication system according to the present embodiment. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be understood easily by considering detailed descriptions below with reference to attached drawings for exemplification. Subsequently, an embodiment of the present invention will be described with reference to attached drawings. The same numerals are attached to the same components if possible to omit duplicate descriptions. FIG. 1 shows a configuration of a mobile communication system 1 including a mobile terminal 30 in which an HLR10 (Home Location Register: authentication vector generating device), a VLR20 (Visitor Location Register: authentication device), and a USIM 40 (User Subscriber Identity Module: subscriber authentication module) according to the present embodiment are mounted. In the mobile communication system 1, a mobile communication network 2 exists for each network operator. If, in the mobile communication system 1, the mobile terminal 30 is not located within communication areas of a mobile communication network of a network operator to which a subscriber of the mobile terminal 30 subscribes, but is located within communication areas (for example, within areas authenticated by the VLR20) of a mobile communication network of another network operator, communication can still be performed via the another network. That is, roaming is possible in the mobile communication system 1. In the present embodiment, it is assumed that a mobile communication network 2a is a mobile communication network of a network operator to which a subscriber of the mobile terminal 30 subscribes (hereinafter, this mobile communication network is referred to as a home network 2a) and a mobile communication network 2b is a mobile communication network of another network operator (hereinafter, this mobile communication network is referred to as a roaming network 2b). It is also assumed that the home network 2a is a network based on IMT-2000 and, for example, a network in Japan, and the roaming network 2b is a network based on GSM and, for example, an overseas network. Each component of the mobile communication system 1 will be described below assuming that the mobile terminal 30 communicates with the home network 2a via the roaming network 2b based on GSM in overseas. The HLR10 is a device for generating an authentication vector (AV) used for authenticating a subscriber authentication module of a mobile communication network and exists in each mobile communication network 2. An HLR of the mobile communication network 2a is assumed to be the HLR 10. As shown in FIG. 1, the HLR 10 includes an authentication vector generation part 11 (authentication vector generating unit), a stop information addition part 12 (adding unit) instructing to cause part or all of functions in the subscriber authentication module to stop, an authentication vector transmission part 13 (authentication vector transmitting unit), a function stop setting part 14 (setting unit), and a request acceptance part 15 (request accepting unit). More specifically, the HLR 10 is preferably realized by an information processing device including a CPU, a memory, and the like. FIG. 2 is a hardware configuration diagram of the HLR 10. As shown in FIG. 2, the HLR 10 is physically configured as a computer system including a CPU 101, a RAM 102 and a ROM 103, which are main storage devices, an auxiliary storage 105, such as a hard disk, an input device 106, such as a keyboard and mouse, which are input devices, an output device 107 such as a display, and a communication module 104, which is a data transmitting/receiving device such as a network card. Each function described in FIG. 1 is realized by operating the communication module 104, the input device 106, and the output device 107 under control of the CPU 101 and also performing read and write operations of data in the RAM 102 and the auxiliary storage 105 by causing hardware such as the CPU 101 and the RAM 102 shown in FIG. 2 to read computer software. Each component will be described below based on a functional block shown in FIG. 1. The authentication vector generation part 11 is a part that generates an authentication vector used for authentication of a subscriber authentication module. An authentication vector is generated by generating electronic data having a plurality of fields. For example, the authentication vector generation part 11 generates an authentication vector consisting of data rows shown in FIG. 3(a). FIG. 3(a) is a schematic view showing an authentication vector based on IMT-2000. As shown in FIG. 3(a), the authentication vector based on IMT-2000 consists of data rows called a quintet. More specifically, an authentication vector of a quintet is shown as data rows consisting of RAND, XRES, CK, IK, and AUTN. Of these data rows, the RAND field is a portion where random numbers for authentication processing are written, and further in the present embodiment, stop information for causing the function of the USIM 40 to stop is written. Here, an authentication vector generated by the HLR 10 of the home network 2a, that is, an authentication vector generated for authenticating a subscriber authentication module owning the USIM 40 will be described. Since the home network 2a is a mobile communication network based on IMT-2000, an authentication vector generated by the HLR 10 of the home network 2a is a quintet having five fields of RAND, XRES, CK, IK, and AUTN as shown in FIG. 3(a). A more specific description will be given below. The XRFS field contains information for verifying operation results carried out by the USIM 40. The information is preferably determined by confidential information and algorithms known only to the HLR 10 and the USIM 40 of a verification target. The CK field contains information for hiding radio channels. The IK field contains information for verifying contents of radio communication. The AUTN field contains information for authenticating the mobile communication network 2 in the USIM 40. Information for identifying the algorithm used for operations for authenticating a quintet is contained in the AMF field included in the AUTN field. When authentication is performed by the VLR 20 of the roaming network 2b, the quintet may be converted into a triplet in some cases (See FIG. 3(b)). Conversion content will be described later. The stop information addition part 12 is a part that adds stop information in the USIM 40 to the RAND field of an authentication vector after reading the authentication vector generated by the authentication vector generation part 11 when location registration processing for the mobile terminal 30 set by the function stop setting part 14 is performed. The authentication vector generated by the authentication vector generation part 11 and to which stop information is added by the stop information addition part 12 is output to the authentication vector transmission part 13. The authentication vector transmission part 13 transmits the authentication vector to which stop information has been added by the stop information addition part 12 to the VLR 20. The function stop setting part 14 is a part that accepts a setting instruction by an operator of the HLR 10 from a control desk called a console (not shown) connected to the HLR 10 and makes a setting thereof. More specifically, the function stop setting part 14 is a part that accepts an instruction to stop part or all of functions of the USIM 40 itself identified by the USIM 40 and makes a setting thereof. In addition to accepting an instruction by an operator from the console, a setting to stop part or all of functions of the USIM 40 itself identified by the USIM 40 through a remote operation via a communication network from a user of the mobile terminal 30 may be accepted and stored. The request acceptance part 15 is a part that accepts a request of an authentication vector from the VLR 20 via a communication part 31 and an interface part 32 of the subscriber terminal equipment. After accepting the request of an authentication vector, the request acceptance part 15 outputs an instruction for generating an authentication vector to the authentication vector generation part 11. The VLR 20 is a device for managing and storing the location of the mobile terminal 30 and uses an authentication vector generated by the HLR 10 to perform actual authentication processing for the mobile terminal 30 and USIM 40. The VLR 20 also exists in each mobile communication network 2 and, if the mobile terminal 30 is connected to the home network 2a by roaming via the roaming network 2b, authentication processing is performed by the VLR 20 of the roaming network 2b. Concrete authentication processing in the VLR 20 will be described later. The mobile terminal 30 is a device used by a subscriber of a mobile communication network to perform communication in the mobile communication system 1. The communication here corresponds, for example, to voice communication, packet communication and the like. As shown in FIG. 1, the mobile terminal 30 includes the communication part 31 having a mobile communication function and the interface part 32 that performs transmission/reception of information to the USIM 40. The USIM 40 is a device mounted in the mobile terminal 30 to carry out operations necessary for authentication of a subscriber authentication module performed by the VLR 20. The USIM 40 is more specifically realized by an IC card mountable to the mobile terminal 30, and preferably stores information about a phone number of a subscriber and a network operator to which the subscriber subscribes. As shown in FIG. 1, the USIM 40 includes a function stop part 41 (stopping unit) executing to cause part or all of functions of the subscriber authentication module to stop, a receiving part 42 (stop information receiving unit), an identification part 43, an operation part 44, and a transmission part 45. The function stop part 41 is a functional part to disable, for example, a function for referring to telephone directory information stored inside the USIM 40 from outside and also a function for referring to a portion in which other information that can be individually set by the user is stored, that is, to stop reference from outside. In addition, the function stop part 41 may also disable network connection using the USIM 40 by stopping all functions (a state in which no response is received) included in the USIM 40, disabling authentication operations, or deleting and resetting information stored in the USIM 40 itself after making a resetting to request input of the PIN code. The receiving part 42 is a part for receiving data used for operation or that for a function stop from the interface part 32 of the mobile terminal 30. Data transmitted from the mobile terminal 30 contains at least information of the RAND field of an authentication vector. The received data is transmitted to the identification part 43. The identification part 43 is a part that identifies stop information in the function stop part 41 by referring to the stop information contained in the RAND field of an authentication vector in the received data. If the identification part 43 identifies the stop information, the information is output to the function stop part 41 to cause a functional stop. The operation part 44 is a part that carries out operations for authentication using the received data. Information of an operation result is transmitted to the transmission part 45 for transmission to the mobile terminal 30. The transmission part 45 is a part that transmits information of an operation result after performing an operation to the mobile terminal 30. The mobile terminal 30 can determine whether or not authentication processing has been completed based on the operation result transmitted by the transmission part 45. Processing performed by the mobile communication system 1 in the present embodiment will be described below with reference to a sequence diagram shown in FIG. 4. The present processing is a process to authenticate the USIM 40 performed when the mobile terminal 30 is located within a communication area (for example, a foreign country in which a network based on GSM is set up) of the roaming network 2b and location registration is performed. First, a request of location registration is transmitted from the mobile terminal 30 mounting the USIM 40, and the VLR 20 of the roaming network 2b managing an area where the mobile terminal 30 is located receives the request. Then, in accordance with the location registration request from the mobile terminal 30, the VLR 20 transmits an allocation request of an authentication vector for authenticating the USIM 40 to the HLR 10 of the home network 2a (S01). It is assumed in the present embodiment that a network operator to which the subscriber of the mobile terminal 30 (USIM 40) subscribes provides communication services to areas managed by the HLR 10. The authentication vector generation part 11 in the HLR 10, which has received the allocation request, generates an authentication vector corresponding to the USIM 40 based on information identifying the USIM 40 contained in the allocation request (S02). Since the home network 2a is based on IMT-2000, as described above, the generated authentication vector is a quintet. Information in the XRES field of the generated authentication vector is usually obtained from random number information contained in the RAND field and confidential information corresponding to the USIM 40 held in advance by the HLR 10 as a result of operation based on a predetermined algorithm. The predetermined algorithm is an algorithm used for operation of authentication by the USIM 40. Subsequently, in the HLR 10, the stop information addition part 12 adds stop information to the RAND field of the generated authentication vector (S03). More specifically, as shown in FIG. 3, it is preferable to provide a stop information field of a predetermined data length, which is a field for identifying stop information, in the RAND field and to contain a character string identifying stop information in this stop information field. At this time, character strings are brought into correspondence with each other in advance, for example, a string “00h” is assumed to be stop information and other strings are not contained in stop information. Since the RAND field needs to contain random number information that should originally be contained in this field, a field for identifying the algorithm should be kept to a minimum. Information for identifying the algorithm may be encrypted by some technique or in plain text. Generation of an authentication vector (S02) and addition of stop information (S03) are separate processing in the above description of the present embodiment, but generation of an authentication vector and addition of stop information may be performed in single processing. The generated authentication vector is transmitted by the authentication vector transmission part 13, and an allocation of the authentication vector is issued. That is, the authentication vector transmission part 13 transmits the authentication vector to the VLR 20 that issued an allocation request of an authentication vector (S04). The VLR 20 receives the transmitted authentication vector. The authentication vector is a quintet, but the roaming network 2b is a network based on GSM and uses a triplet for authentication and thus the VLR 20 converts the quintet into a triplet (S05). More specifically, this conversion is performed as shown in FIG. 3. As shown in FIG. 3, data in the RAND field becomes data in the RAND field of a triplet without undergoing any conversion. Data in the XRES field becomes data in the RES field of the triplet after conversion by a predetermined function c2. Data in the CK and IK fields become data in a Kc field of the triplet after conversion by a predetermined function c3. Data in the AUTN field is deleted during conversion to the triplet. Since information for identifying stop information is contained in the RAND field that is not converted by any function, the information is inherited as it is. The above conversion to a triplet is performed by the VLR 20, but in some mobile communication systems, conversion to a triplet is performed by the HLR 10 before transmission to the VLR 20. Subsequently, the VLR 20 transmits information for authentication to the USIM 40 (S06). The information for authentication contains at least information in the RAND field. The transmission is performed via base stations (not shown) and the communication part 31 and interface part 32 of the mobile terminal 30. Subsequently, in the USIM 40, the receiving part 42 receives information for authentication transmitted from the mobile terminal 30, that is, data used for operation for authentication. After the data is received by the receiving part 42, the identification part 43 reads the data. The identification part 43 refers to stop information contained in the RAND field and outputs an instruction to stop functions to the function stop part 41. After receiving the instruction, the function stop part 41 stops part or all of functions of the USIM (S07). More specifically, identification of stop information is preferably performed by reading a character string in the RAND field and using correspondence information between the character string and a character string held in advance. Subsequently, the operation part 44 carries out an operation for authentication based on a predetermined algorithm (S08). An operation result is transmitted to the transmission part 45, and the transmission part 45 transmits the operation result to the mobile terminal 30. The transmitted operation result is transmitted to the VLR 20 via the communication part 31 of the mobile terminal 30 and base stations (S09). After receiving the operation result, the VLR 20 uses information for authentication contained in the XRES field of an authentication vector to verify whether or not the operation result is valid to authenticate the USIM 40 (S10). More specifically, the verification is performed by determining whether a value contained in the XRES field and that of the operation result are the same. By performing the above operation processing for authentication and authentication processing thereof, processing for location registration can normally be terminated, but if functions are stopped including processing thereafter (processing of S08 and thereafter), the USIM 40 can safely omit processing of S08 and thereafter. Thus, according to the present embodiment, stop information is identified before stopping functions even if the roaming network 2b is a network based on GSM. Therefore, functions of the USIM 40 can still be stopped when the mobile terminal 30 is in a roaming network. Points where modifications are needed in the present embodiment from a conventional mobile communication system include a generation process of an authentication vector of the HLR 10 (S02 and S03 in FIG. 4) and a stop process based on stop information of the USIM 40 (S07 in FIG. 4) only and the VLR 20 needs no modification at all, and therefore, the present embodiment can be realized reasily. The above embodiment assumes that roaming occurs between a network based on IMT-2000 and that based on GSM, and a technology of the present invention can also be applied for authentication in a GSM network. That is, in a GSM network, the HLR inserts information for identification of stop information in a subscriber authentication module (called SIM (Subscriber Identity Module) in GSM) into the RAND field of a triplet. The above processing enables realization of a function stop even in GSM that does not assume a function stop in terms of specification. To realize the above function stop, the USIM 40 must perform an authentication operation. Thus, it is preferable to perform a function accompanied by an authentication operation such as an incoming operation on subscriber information of the USIM 40 from a home network. Next, operation effects of the mobile communication system in the present embodiment will be described. According to the HLR 10 in the present embodiment, a setting is made to the effect that part or all of functions of the USIM 40 should be caused to stop based on an instruction from an operator operating the HLR 10 or a user who has lost the mobile terminal 30. Then, a request of an authentication vector from the VLR 20 whose location registration has been performed from the set mobile terminal 30 is accepted, an authentication vector for authenticating the USIM 40 in the mobile terminal 30 is generated, stop information instructing to cause part or all of functions of the USIM 40 to stop is added to the RAND field of the generated authentication vector so that the authentication vector to which the stop information is added can be transmitted to the VLR 20. An authentication vector for stopping functions is thereby generated in accordance with a location registration request from the subscriber terminal equipment such as the mobile terminal 30 and, therefore, the functions can be quickly stopped when the mobile terminal 30 is located where radio waves are received. Further, since stop information is added to the RAND field in the authentication vector, information for stopping can reliably be transmitted to the mobile terminal 30 without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM and that based on IMT-2000 due, for example, to roaming. The USIM 40 in the present invention receives stop information written in the RAND field of an authentication vector to cause part or all of functions of the USIM 40 to stop and, based on the stop information contained in the received authentication vector, part or all of functions of the USIM 40 or part or all of functions of the mobile terminal 30 can be caused to stop. Functions set in the authentication vector can thereby be quickly stopped in the mobile terminal 30 if a location registration request can be made, that is, if the mobile terminal 30 is located where radio waves are received. Also, function stop processing can be performed based on stop information for stopping the functions set to the RAND field of the authentication vector and stop information can reliably be extracted to stop the functions without being deleted or converted while converting a quintet into a triplet even if communication passes through a network based on GSM and that based on IMT-2000 due, for example, to roaming.
|
H
|
H04
|
H04M
|
1
|
66
|
|||
11720067
|
US20080079605A1-20080403
|
Sonde Attachment Means
|
ACCEPTED
|
20080318
|
20080403
|
[]
|
G01V318
|
["G01V318"]
|
8451136
|
20070523
|
20130528
|
340
|
853100
|
72723.0
|
BENLAGSIR
|
AMINE
|
[{"inventor_name_last": "Jaques", "inventor_name_first": "Paul", "inventor_city": "Cornwall", "inventor_state": "", "inventor_country": "GB"}, {"inventor_name_last": "Jones", "inventor_name_first": "Robert", "inventor_city": "Cambridge", "inventor_state": "", "inventor_country": "GB"}]
|
A sonde for installation in a well including a clamp (2) for engaging with the inner wall of a well casing (3) and securing device for securing the clamp to inner tubing of the well, whereby the securing device includes an attachment device (5, 6) for connection to the inner tubing and a rod (4) connected between the clamp and the attachment device.
|
1. A sonde for installation in a well comprising a clamp for engaging with the inner wall of a well casing and securing means for securing the clamp to inner tubing of the well, characterised by the securing means comprising attachment means for connection to the inner tubing and a rod connected between the clamp and the attachment means. 2. A sonde according to claim 1, wherein the dimensions and/or material of the rod are selected so as to minimise transfer of noise from the tubing to the sonde. 3. A sonde according to claim 1, wherein the securing means comprises a plurality of such rods. 4. A sonde according to claim 3, wherein at least one such rod and attachment means is provided on each side of the clamp along the axis of the well in use. 5. A sonde according to claim 1, wherein the attachment means is soft mounted to the tubing. 6. A sonde according to claim 1, wherein the attachment means comprises electrical distribution means enabling electrical connection between the sonde and wellhead components, the electrical distribution means being fixed relative to the sonde. 7. A sonde according to claim 1, wherein the clamp is substantially C-shaped. 8. A sonde according to claim 1, wherein the clamp carries a sensor. 9. A sonde according to claim 8, wherein the sensor is electrically connected to the electrical distribution means. 10. A well assembly comprising a well, a well casing lining the wall of the well, tubing extending internally through the well and a sonde in accordance with any preceding claim. 11. A method of installing acoustic sensing equipment in a well, comprising the steps of: providing a sonde in accordance with claim 1, fitting the sonde to the inner tubing of a well while the clamp is in a retracted state, expanding the clamp so that it contacts the inner wall of the well casing, and pushing the sonde along the well to its desired position. 12. A method of sensing acoustic vibration in a well, comprising the steps of: providing a sonde in accordance with claim 1, installing the sonde at a desired position in the well so that acoustic sensing equipment carried by the sonde is held against the inner wall of the well casing.
|
<SOH> BACKGROUND <EOH>Microseismic analysis of the geological strata around the bore of fluid injection and production wells is typically effected by the use of seismic sensor assemblies (sondes), mounted downhole in the area of the fluid flow. Usually a number of sondes are mounted in the well at different levels in the bore. Deployment techniques have been developed to allow the sensors to become almost completely mechanically decoupled from the flow induced noise from the tubing. Systems for permanently installing a sonde against an inner wall of a pipe, such as the casing of a fluid extraction well, are known. Such systems are described in, for example, U.S. Pat. Nos. 5,092,423, 5,181,565, 5,200,581, 5,111,903, 6,289,985, 6,173,804 and 5,318,129. Typically, a sonde comprises a clamp which permanently or semi-permanently engages with the inner casing of a well. For example, the clamp may be lowered into the well in a retracted state and then once in position activated to engage with the well casing using a pressure actuated system, which may use external pressure sources or well pressure. Such a clamp is described in patent application no. EP-A-1370891, the contents of which are incorporated herein by reference, which describes C-shaped ring clamps. It is also possible to activate the clamp near the top of the well, and simply drag it down the well, acting against friction between the clamp and well casing, into the desired position. A disadvantage of these systems is that because the sondes (for example with C-shaped ring clamps) are released from the tubing and clamped to the inside of the casing, any large tubing movement, i.e. typically more than 15 cm, can cause the risk of coupling the sondes back to the tubing. Such movement is invariably axial or rotational. These systems only perform at their best when the tubing movement is small. Small movements can also be accommodated by the wires from the sensors mounted on the casing and running up the tubing, whereas large movements will result in breakage of these wires. Well completions differ significantly from well to well and temperature changes cause thermal expansion to the installed tubing. Completions have to be designed to allow for the tubing axial or rotational movement, and this can be done by the installation of a seal bore packer for example. For well completions of this type where tubing movement occurs, it would therefore be preferable to provide a means of allowing the sondes to move along the inside of the casing when the tubing moves while maintaining good mechanical decoupling. With such an arrangement, the sondes must be able to move along the axis of the borehole when the tubing moves, this tubing movement being possible in either direction. Therefore, the sonde must be secured to the tubing by some mechanical means which must have the following properties: a) it is strong enough to allow the sonde to be dragged along the casing; b) it does not change the frequency properties of the sonde by changing or adding unwanted resonance; and c) most importantly, it does not provide a path for flow noise from tubing to sonde. It is an object of the present invention to provide a sonde having such securement means.
|
<SOH> SUMMARY OF THE INVENTION <EOH>In accordance with a first object of the present invention there is provided a sonde for installation in a well comprising a clamp for engaging with the inner wall of a well casing and securing means for securing the clamp to inner tubing of the well, characterised by the securing means comprising attachment means for connection to the inner tubing and a rod connected between the clamp and the attachment means. Advantageously, the dimensions and/or material of the rod are selected so as to minimise transfer of noise from the tubing to the sonde. The securing means preferably comprises a plurality of such rods. With this arrangement, at least one such rod and attachment means may be provided on each side of the clamp along the axis of the well. Advantageously, the attachment means is soft mounted to the tubing. The attachment means may comprise electrical distribution means enabling electrical connection between the sonde and wellhead components, the electrical distribution means being fixed relative to the sonde. The clamp may be substantially C-shaped. Preferably, the clamp carries a sensor. The sensor may be electrically connected to the electrical distribution means. In accordance with a second aspect of the present invention, there is provided a well assembly comprising a well, a well casing lining the wall of the well, tubing extending internally through the well and a sonde in accordance with the first aspect of the invention. In accordance with a third aspect of the present invention, there is provided a method of installing acoustic sensing equipment in a well, comprising the steps of: providing a sonde in accordance with any preceding claim, fitting the sonde to the inner tubing of a well while the clamp is in a retracted state, expanding the clamp so that it contacts the inner wall of the well casing, and pushing the sonde along the well to its desired position. In accordance with a fourth aspect of the present invention, there is provided a method of sensing acoustic vibration in a well, comprising the steps of: providing a sonde in accordance with any preceding claim, installing the sonde at a desired position in the well so that acoustic sensing equipment carried by the sonde is held against the inner wall of the well casing. Thus the object of the invention is achieved by connecting at least one rigid “tether rod” between the sonde and the tubing. A plurality of such rods may be fitted above and below the sonde and attach on to this tubing at soft mounted interfaces above and below the sonde. The cross sectional area of the rods must be small in comparison to the cross sectional area of the tubing, which provides a high ‘impedance’ mismatch between cable and tubing. In popular science terms: compare this to a thin rope connected to a heavy rope. If you swing the thin rope, a travelling wave will propagate through the rope, when it reaches the heavy rope this wave will be largely reflected, instead of travelling along the heavy rope. This works two ways, if you swing the heavy rope the wave will also be reflected at the thin rope instead of travelling further along the thin rope. Thus, although the sonde is mechanically coupled to the installed tubing, it is effectively isolated, acoustically, from the noise generated by the fluid flow in the tubing. The dimensions, especially the diameter, and the material of the tether rods can be calculated to provide such acoustic isolation over the band of frequencies required to be sensed by the sonde, taking into account the choice of material for the rods. Embodiments in accordance with the invention have the following advantages over the prior art: i) The acoustic sensors remain acoustically decoupled from the flow noise; ii) Potential damage to the sensor electrical wiring by tubing movement is prevented; iii) A strong connection to the tubing is provided. The rod size and number can be adjusted to suit requirements; iv) There is no low frequency resonance added in the seismic frequency band; v) The rods can be fitted to any shaped clamp equipment; and vi) Deployment from the surface is enabled without any remote actuation equipment. Therefore, the tool may be dragged down from the surface during installation. No actuation mechanism, e.g. downhole pressure supply is required, and the need for a threaded section of tubing required by prior art systems, typically 1500 mm long and carrying the pre-assembled clamp system, is eliminated.
|
This invention relates to a sonde for installation in a well, a well assembly comprising such a sonde, and methods for installing acoustic sensing equipment in a well and sensing acoustic vibration in a well. BACKGROUND Microseismic analysis of the geological strata around the bore of fluid injection and production wells is typically effected by the use of seismic sensor assemblies (sondes), mounted downhole in the area of the fluid flow. Usually a number of sondes are mounted in the well at different levels in the bore. Deployment techniques have been developed to allow the sensors to become almost completely mechanically decoupled from the flow induced noise from the tubing. Systems for permanently installing a sonde against an inner wall of a pipe, such as the casing of a fluid extraction well, are known. Such systems are described in, for example, U.S. Pat. Nos. 5,092,423, 5,181,565, 5,200,581, 5,111,903, 6,289,985, 6,173,804 and 5,318,129. Typically, a sonde comprises a clamp which permanently or semi-permanently engages with the inner casing of a well. For example, the clamp may be lowered into the well in a retracted state and then once in position activated to engage with the well casing using a pressure actuated system, which may use external pressure sources or well pressure. Such a clamp is described in patent application no. EP-A-1370891, the contents of which are incorporated herein by reference, which describes C-shaped ring clamps. It is also possible to activate the clamp near the top of the well, and simply drag it down the well, acting against friction between the clamp and well casing, into the desired position. A disadvantage of these systems is that because the sondes (for example with C-shaped ring clamps) are released from the tubing and clamped to the inside of the casing, any large tubing movement, i.e. typically more than 15 cm, can cause the risk of coupling the sondes back to the tubing. Such movement is invariably axial or rotational. These systems only perform at their best when the tubing movement is small. Small movements can also be accommodated by the wires from the sensors mounted on the casing and running up the tubing, whereas large movements will result in breakage of these wires. Well completions differ significantly from well to well and temperature changes cause thermal expansion to the installed tubing. Completions have to be designed to allow for the tubing axial or rotational movement, and this can be done by the installation of a seal bore packer for example. For well completions of this type where tubing movement occurs, it would therefore be preferable to provide a means of allowing the sondes to move along the inside of the casing when the tubing moves while maintaining good mechanical decoupling. With such an arrangement, the sondes must be able to move along the axis of the borehole when the tubing moves, this tubing movement being possible in either direction. Therefore, the sonde must be secured to the tubing by some mechanical means which must have the following properties: a) it is strong enough to allow the sonde to be dragged along the casing; b) it does not change the frequency properties of the sonde by changing or adding unwanted resonance; and c) most importantly, it does not provide a path for flow noise from tubing to sonde. It is an object of the present invention to provide a sonde having such securement means. SUMMARY OF THE INVENTION In accordance with a first object of the present invention there is provided a sonde for installation in a well comprising a clamp for engaging with the inner wall of a well casing and securing means for securing the clamp to inner tubing of the well, characterised by the securing means comprising attachment means for connection to the inner tubing and a rod connected between the clamp and the attachment means. Advantageously, the dimensions and/or material of the rod are selected so as to minimise transfer of noise from the tubing to the sonde. The securing means preferably comprises a plurality of such rods. With this arrangement, at least one such rod and attachment means may be provided on each side of the clamp along the axis of the well. Advantageously, the attachment means is soft mounted to the tubing. The attachment means may comprise electrical distribution means enabling electrical connection between the sonde and wellhead components, the electrical distribution means being fixed relative to the sonde. The clamp may be substantially C-shaped. Preferably, the clamp carries a sensor. The sensor may be electrically connected to the electrical distribution means. In accordance with a second aspect of the present invention, there is provided a well assembly comprising a well, a well casing lining the wall of the well, tubing extending internally through the well and a sonde in accordance with the first aspect of the invention. In accordance with a third aspect of the present invention, there is provided a method of installing acoustic sensing equipment in a well, comprising the steps of: providing a sonde in accordance with any preceding claim, fitting the sonde to the inner tubing of a well while the clamp is in a retracted state, expanding the clamp so that it contacts the inner wall of the well casing, and pushing the sonde along the well to its desired position. In accordance with a fourth aspect of the present invention, there is provided a method of sensing acoustic vibration in a well, comprising the steps of: providing a sonde in accordance with any preceding claim, installing the sonde at a desired position in the well so that acoustic sensing equipment carried by the sonde is held against the inner wall of the well casing. Thus the object of the invention is achieved by connecting at least one rigid “tether rod” between the sonde and the tubing. A plurality of such rods may be fitted above and below the sonde and attach on to this tubing at soft mounted interfaces above and below the sonde. The cross sectional area of the rods must be small in comparison to the cross sectional area of the tubing, which provides a high ‘impedance’ mismatch between cable and tubing. In popular science terms: compare this to a thin rope connected to a heavy rope. If you swing the thin rope, a travelling wave will propagate through the rope, when it reaches the heavy rope this wave will be largely reflected, instead of travelling along the heavy rope. This works two ways, if you swing the heavy rope the wave will also be reflected at the thin rope instead of travelling further along the thin rope. Thus, although the sonde is mechanically coupled to the installed tubing, it is effectively isolated, acoustically, from the noise generated by the fluid flow in the tubing. The dimensions, especially the diameter, and the material of the tether rods can be calculated to provide such acoustic isolation over the band of frequencies required to be sensed by the sonde, taking into account the choice of material for the rods. Embodiments in accordance with the invention have the following advantages over the prior art: i) The acoustic sensors remain acoustically decoupled from the flow noise; ii) Potential damage to the sensor electrical wiring by tubing movement is prevented; iii) A strong connection to the tubing is provided. The rod size and number can be adjusted to suit requirements; iv) There is no low frequency resonance added in the seismic frequency band; v) The rods can be fitted to any shaped clamp equipment; and vi) Deployment from the surface is enabled without any remote actuation equipment. Therefore, the tool may be dragged down from the surface during installation. No actuation mechanism, e.g. downhole pressure supply is required, and the need for a threaded section of tubing required by prior art systems, typically 1500 mm long and carrying the pre-assembled clamp system, is eliminated. DESCRIPTION OF DRAWINGS The invention will now be described by way of example with reference to the accompanying drawings, in which: FIG. 1 shows a first embodiment of the sonde in position in a well, the sonde comprising a C-shaped ring clamp; and FIG. 2 shows a second embodiment in which the sonde comprises a different C-shaped clamp. DETAILED DESCRIPTION FIG. 1 shows a first embodiment of the invention wherein the sonde comprises a C-shaped spring clamp design as described in the patent application no. EP-A-1370891. Typically four acoustic sensors 1 are mounted in the C-shaped clamp 2. The clamp 2 may be positioned within the well casing 3 by being fitted over production tubing 7, compressed by a mechanical assembly and released hydraulically when the assembly has been lowered down the well casing 3, to the required depth down the well. Alternatively the clamp may be compressed (e.g. manually) and fitted over tubing 7 near the top of the well and then allowed to engage the well casing and simply slide down the well in contact with the casing 3 until it is in position. As shown in this embodiment, the C-shaped sonde clamp 2 is attached to thin rigid tether rods 4, typically six rods being used, i.e. three above and three below. The other ends of the rods are connected to attachment means 5 and 6 which are in turn affixed to the tubing 7. The attachments 5 and 6 may be soft-mounted to tubing 7, e.g. using a resiliently deformable material, such as a suitable polymer, between the attachment and the tubing, which acts to dampen acoustic vibration to prevent noise transfer between the tubing and the clamp, and hence to sensors 1. The attachment 5 also supports a distribution unit 8 which provides an electrical interface between the wires 9, from each of the acoustic sensors 1, and the cable 10 to the wellhead and its acoustic signal processing system. Since the sonde is mechanically coupled to the distribution unit, i.e. the distribution unit is secured relative to the sonde, any movement of the well casing relative to the tubing does not result in damage to the electrical wiring, which is a potential risk in conventional systems. In the second of the above positioning methods, installation of the sonde is effected by fixing the whole assembly, consisting of the sonde clamp 2 with sensors 1 coupled to the attachments 5 and 6 by the tether rods 4, pre-wired to distribution unit 8 and cable 10, to the tubing 7, prior to lowering the tubing 7 down the well. With the assembly attached to the tubing 7, the clamp 1 is compressed manually to allow it to slip into the casing, facilitated by the chamfered edges of the clamp. The tubing may then be lowered down the well with the clamp 2 sliding down the casing 3, with the force to enable it to do so transmitted from the tubing 7 via the attachments 5 and 6 and the tether rods. This does not damage either the clamp or the well casing as the clamp is typically made of a very hard material, for example Inconel®, and also due to the lubricating effect of fluid in the well. Alternatively, the clamp may be retained in its compressed state until the correct position is reached down the well. FIG. 2 shows a second embodiment of the invention applied to an alternative design of sonde C-shaped clamp which is also described in EP-A-1370891. In this case, sonde packs 11 each consisting of typically four sensors arranged in a tetrahedral configuration are attached to a spring clamp 12. In the same manner as in the first embodiment, the clamp is attached to typically six thin rigid tether rods 4, i.e. three above and three below, the other ends of the rods 4 connected to attachments 5 and 6 which are also affixed to the tubing 7 as in the first embodiment. The method of installation is somewhat different to the first embodiment though. The clamp shown in FIG. 2 is contracted and expanded by physical manipulation of the members 13 at the ends of the C-shape. In practice, a forked member (not shown) like in EP-A-1370891 is used to hold the members 13 together to contract the clamp until it is inserted into the well. The clamp may then either by positioned while the clamp is retracted and then expanded to hold it in position against the well casing, or expanded near the top of the well and pushed down to the desired position against the well casing. Expansion of the clamp is effected by removing the forked member from engagement with members 13, so that the clamp moves into the expanded state. Sliding the expanded clamp down the casing does not damage either the clamp or the well casing as the clamp is typically made of a very hard material, for example Inconel®, and also due to the lubricating effect of fluid in the well. It should be noted that both forms of clamp provide substantial force to press the sonde to the well casing to ensure good acoustic coupling. Experimental work with a prototype has demonstrated that the sliding friction force within the casing is sufficiently low for the tether rods to adequately overcome these forces during installation. It should be noted that the invention is not limited to the embodiments shown, and various alternatives are possible within the scope of the claims. For example, although the invention has been described with reference to C-shaped clamps, any design of clamp may be used which can have the rods attached thereto.
|
G
|
G01
|
G01V
|
3
|
18
|
|||
11759962
|
US20080301999A1-20081211
|
Personal Fish Sack Carrier
|
ACCEPTED
|
20081122
|
20081211
|
[]
|
A01K9720
|
["A01K9720"]
|
8371061
|
20070608
|
20130212
|
43
|
055000
|
90113.0
|
PARSLEY
|
DAVID
|
[{"inventor_name_last": "Bergers", "inventor_name_first": "Jeffrey Lawrence", "inventor_city": "Grand Rapids", "inventor_state": "MI", "inventor_country": "US"}]
|
The invention is a fish transport sack specifically designed to transport larger fish such as salmon or steelhead by wading or pedestrian fisherman. The salmon is a large fish approximately 10 to 30 pounds in weight and lengths sometimes exceeding 30 inches. A fish of this size is cumbersome to carry by hand in the traditional method with a stringer, particularly when long distances need to be traversed across rugged terrain such as steep hills and fallen trees. The dangling of the fish on the stringer causes considerable strain on the fisherman's hands, wrist, arms, and shoulders. The discomfort is compounded when several large fish need to be carried simultaneously. The fish sack carrier (10) is of an oblong fish-like shape in order to position the fish in a vertical position with its head downward. This position reduces strain on the fisherman by evenly distributing the weight on their back and shoulder. A unique suspension system (14) design stabilizes and balances the fish in a comfortable position high upon the fisherman's back, and provides for additional fish sacks (58) to be easily connected to a common shoulder strap and carried simultaneously. The fish sack carrier (10) is constructed of lightweight and durable materials, is washable after use, and can be folded into a small packet for pocket storage.
|
1. A fisherman's personal fish carrier comprising: a) a flexible cigar-shaped receptacle of predetermined length and width, b) an open end with closure means, c) a suspension system securely attached to said receptacle and said open end, whereby one or several fish of substantial size and weight can be carried comfortably hands free on the back of the pedestrian fisherman for transport. 2. A fisherman's personal fish carrier according to claim 1 wherein said receptacle is an oblong fish shape of sufficient length and width to accommodate a mature salmon or steelhead in a vertical position, 3. A fisherman's personal fish carrier according to claim 1 wherein said receptacle is constructed of a durable water resistant fabric securely attached to a longitudinal section of water pervious mesh fabric by stitching, 4. A fisherman's personal fish carrier according to claim 1 wherein said open end has a hem formed by inwardly doubling over fabric and stitching, 5. A fisherman's personal fish carrier according to claim 1 wherein said receptacle has a closed bottom end formed by stitching, 6. A fisherman's personal fish carrier according to claim 1 wherein said suspension system consists of an interlocking upper and lower shoulder strap with free ends containing opposite mating sides of a two component, side-release, quick connect buckle, 7. A fisherman's personal fish carrier according to claim 6 wherein said upper shoulder strap further includes a shoulder pad, 8. A fisherman's personal fish carrier according to claim 6 wherein said upper shoulder strap threads through said hem at the top opening of said sack and then is stitched upon itself to form a handling loop at one terminal end and the other free end threads through said shoulder pad and one said mating side of connecting buckle and is folded back upon itself and secured by stitching to form another handling loop, 9. A fisherman's personal fish carrier of claim 6 wherein said lower shoulder strap threads through a plurality of said mating sides of connecting buckle and terminates to another said mating side of connecting buckle by stitching, 10. A fisherman's personal fish carrier of claim 6 wherein said lower shoulder strap further includes a snap clip at one terminal end and a tie ring securely attached by stitching, 11. A fisherman's personal fish carrier of claim 6 wherein said lower shoulder strap further includes a strap adjuster securely attached by stitching on one side and by threading a separate section of said strap through the opposite side providing strap length adjustment, 12. A fisherman's personal fish carrier of claim 1 wherein said sack further includes two connector rings each securely attached to one opposite side of said sack at an equal position along the length of said sack by stitching, 13. A fisherman's personal fish carrier of claim 1 further including a cord removably attached at one free end with a snap clip to one said connector ring on one side of said sack, 14. A fisherman's personal fish carrier of claim 1 further including a cinch strap securely attached at one end to one side of said sack and connector ring by stitching and loosely encircling around the width of the said sack extending through said connector rings, 15. A fisherman's personal fish carrier of claim 14 wherein said cinch strap further includes a section of hook and loop fastening fabric rigidly affixed to its free end and a mating section of its main length for securing.
|
<SOH> BACKGROUND <EOH>1. Field of Invention This invention relates to fish carrier devices, and more specifically to a fish sack used for the transport of larger fish such as salmon and steelhead by a wading or pedestrian fisherman. 2. Description of Prior Art There are a number of fish carrier devices or receptacles invented for the carrying or transport of fish, particularly by the wading or pedestrian fisherman. These vary in form and method from simple cord stringers where the fish is carried by hand, to specially designed evaporative-cooled, bag shaped, receptacles or creels with an attached shoulder strap, where the fish is carried with its weight supported over the fisherman's shoulder. There is no previously known bag shaped carrier device for a wading or pedestrian fisherman specially designed to efficiently and comfortably transport larger and heavier fish such as salmon or steelhead. There are several creels invented for the wading fisherman to transport smaller size fish such as stream trout. U.S. Pat. No. 2,295,889 to Garland (1957) discloses a mesh fish bag with a clip device that attaches to the belt of a wading fisherman. U.S. Pat. No. 2,555,128 to Gutshall (1951) discloses an evaporative-cooled fishing creel with a strap for carrying over one shoulder. U.S. Pat. No. 3,674,188 to Anderson (1972) discloses an evaporative-cooled fish and game receptacle with a shoulder strap. All of these inventions are similar in that they are designed to transport several smaller size fish either alive or preserved in a moisture cooled. None of these inventions is specially designed to transport large and heavy fish such as salmon in a secure, balanced, and comfortable position over sometimes long walking distances and across rugged terrain such as steep hills and fallen trees. The use of fish stringers constructed of braided nylon with a ring at one end and a needle shaped point at the opposite end are commonly deployed by salmon and steelhead wading fishermen to transport their catch. The fish is carried by threading the needle end of the stringer through a passage on one side of the fish gills and mouth, and then the stringer ring, and then grasping the free end of the stringer by the hand or attaching to a stick. This carry method poses several problems: (a) One fish can weigh upwards of 20 pounds and can exceed 30 inches in length. This is a difficult and strenuous method of transport especially when several fish need to be carried at once and the substantial weight imparts considerable strain on the fisherman's hand, wrist, arm, and shoulder. (b) This method soils and damages the fish since the fish is dangling unbalanced by a stringer threaded through its mouth and gills and sometimes dragged along the ground when too heavy a fish is transported, or adverse walking terrain such as steep hills need to be navigated. It is clear that, with the increasing popularity of fishing for larger size fish, such as salmon and steelhead, there is a need for a better method for the wading or pedestrian fisherman to comfortably and efficiently transport these large and heavy fish.
|
<SOH> SUMMARY <EOH>A lightweight, durable, and washable personal fish carrier device with a suspension system design that provides ease of use, comfort, and economy. The fish sack carrier is designed to efficiently carry hands free a single large and heavy fish such as a salmon or steelhead in a balanced vertical position on the back of the wading or pedestrian fisherman. The unique suspension system design allows additional fish sacks to be simply connected to a single, common, shoulder strap with a minimum amount of effort.
|
CROSS REFERENCE TO RELATED APPLICATIONS Not applicable. BACKGROUND 1. Field of Invention This invention relates to fish carrier devices, and more specifically to a fish sack used for the transport of larger fish such as salmon and steelhead by a wading or pedestrian fisherman. 2. Description of Prior Art There are a number of fish carrier devices or receptacles invented for the carrying or transport of fish, particularly by the wading or pedestrian fisherman. These vary in form and method from simple cord stringers where the fish is carried by hand, to specially designed evaporative-cooled, bag shaped, receptacles or creels with an attached shoulder strap, where the fish is carried with its weight supported over the fisherman's shoulder. There is no previously known bag shaped carrier device for a wading or pedestrian fisherman specially designed to efficiently and comfortably transport larger and heavier fish such as salmon or steelhead. There are several creels invented for the wading fisherman to transport smaller size fish such as stream trout. U.S. Pat. No. 2,295,889 to Garland (1957) discloses a mesh fish bag with a clip device that attaches to the belt of a wading fisherman. U.S. Pat. No. 2,555,128 to Gutshall (1951) discloses an evaporative-cooled fishing creel with a strap for carrying over one shoulder. U.S. Pat. No. 3,674,188 to Anderson (1972) discloses an evaporative-cooled fish and game receptacle with a shoulder strap. All of these inventions are similar in that they are designed to transport several smaller size fish either alive or preserved in a moisture cooled. None of these inventions is specially designed to transport large and heavy fish such as salmon in a secure, balanced, and comfortable position over sometimes long walking distances and across rugged terrain such as steep hills and fallen trees. The use of fish stringers constructed of braided nylon with a ring at one end and a needle shaped point at the opposite end are commonly deployed by salmon and steelhead wading fishermen to transport their catch. The fish is carried by threading the needle end of the stringer through a passage on one side of the fish gills and mouth, and then the stringer ring, and then grasping the free end of the stringer by the hand or attaching to a stick. This carry method poses several problems: (a) One fish can weigh upwards of 20 pounds and can exceed 30 inches in length. This is a difficult and strenuous method of transport especially when several fish need to be carried at once and the substantial weight imparts considerable strain on the fisherman's hand, wrist, arm, and shoulder. (b) This method soils and damages the fish since the fish is dangling unbalanced by a stringer threaded through its mouth and gills and sometimes dragged along the ground when too heavy a fish is transported, or adverse walking terrain such as steep hills need to be navigated. It is clear that, with the increasing popularity of fishing for larger size fish, such as salmon and steelhead, there is a need for a better method for the wading or pedestrian fisherman to comfortably and efficiently transport these large and heavy fish. SUMMARY A lightweight, durable, and washable personal fish carrier device with a suspension system design that provides ease of use, comfort, and economy. The fish sack carrier is designed to efficiently carry hands free a single large and heavy fish such as a salmon or steelhead in a balanced vertical position on the back of the wading or pedestrian fisherman. The unique suspension system design allows additional fish sacks to be simply connected to a single, common, shoulder strap with a minimum amount of effort. OBJECT AND ADVANTAGES Accordingly, the object of the fish sack carrier is to provide for the wading or pedestrian fisherman an efficient, comfortable, and affordable device for transporting larger and heavier fish such as salmon or steelhead across sometimes long distances and rugged walking terrain. Several objects and advantages of the present invention are: (a) to provide an oblong, fish shaped enclosure to comfortably carry a single larger size fish in a vertical position with its head downward high upon the fisherman's back. This position balances, secures, and evenly distributes the weight of the fish upon the fisherman's back and shoulder. (b) to provide a fish transport device that will properly support a single large fish and yet is capable of transporting additional fish by attaching a second or third fish sack to a single, common, shoulder strap. (c) to provide a simple and lightweight shoulder strap design that allows a fast and easy method for lifting the fish over the shoulder, buckling, and adjusting. (d) to provide a hands free fish transport device that can be carried over either shoulder and allows the fisherman to carry other objects with both free hands. (e) to provide a fish transport device with one water resistant side to keep the fisherman's back clean and dry and the opposite side of mesh fabric to allow drainage, cooling, and for the sack to be immersed in water with adequate water circulation to keep the fish alive and preserved until transporting. (f) to provide a fish transport device that keeps the fish clean during transport and is easily washable. (g) to provide a strong, durable, and lightweight fish transport device that is foldable into a small packet that can be stored in a pocket for later use. (h) to provide a carrying loop that can be used to comfortably hand carry the fish sack and can be used to lift and hold the fish enclosed in the sack over either shoulder. (i) to provide a removable section of shoulder strap to allow the sack to be washed by laundering. Further objects and advantages of the invention will become apparent from consideration of the drawings and ensuing description. DESCRIPTION OF DRAWINGS FIGS. 1 and 2 are perspective views of the fish sack when empty and when in use. FIGS. 3 and 4 are perspective views of a second added fish sack when empty and in use. REFERENCE NUMBERS IN DRAWINGS 10 fish sack carrier 12 sack 14 suspension system 16 lower shoulder strap 18 upper shoulder strap 20 stitching 22 sack fabric 24 mesh fabric 26 sack bottom end 28 sack top opening 30 cinch strap 32 connector ring 34 hook and loop fabric 36 strap 38 carry loop 40 shoulder pad 42 female buckle end 44 lift loop 46 snap clip 48 male buckle end 50 strap adjuster 52 tie ring 54 lateral cord 56 snap clip 58 additional fish sack DESCRIPTION—FIGS. 1-4—MAIN EMBODIMENT A preferred embodiment of the invention is shown FIG. 1. A fish sack carrier 10 is generally comprised of a sack 12 and a suspension system 14. Suspension system 14 includes a lower shoulder strap 16, upper shoulder strap 18, and lateral cord 54. FIG. 2 illustrates the invention in use. Sack 12 is constructed of a lightweight, durable, and water-resistant fabric 20, such as nylon or polyester, forming the back and part of the front side of sack 12. Fabric 20 is rigidly attached, on the front side of sack 12, to a narrow, longitudinal, section of water-resistant, durable, fabric mesh 24, such as nylon or polyester, with stitching 20. Stitching 20 forms a closed sack bottom end 26 and a hem at sack top opening 28. A cinch strap 30 and a plastic connector ring 32a are attached together by stitching 20 to one side of sack 12 near the longitudinal center of sack 12. Cinch strap 30 threads through a second plastic connector ring 32b and encircles completely around the circumference of sack 12 and threads through connector ring 32a. Cinch strap 30 is 25 mm wide polypropylene webbing material and has a sewn section of hook and loop fastener fabric 34 for securing its tag end by pressing it onto the main length of cinch strap 30. Upper shoulder strap 18 consists of a 40 mm wide strap 34, of a material such as heavyweight polypropylene, loosely threaded through the hem at the sack top opening 28. Both free ends of strap 36 exits the hem at the backside and center of top opening 28. One free end is sewn onto the main length of strap 36 to form a hand carry loop 38. The other free end of strap 36 threads through a shoulder pad 40, and then a plastic side-release female buckle end 42 and is folded back onto its main length and sewn at the same point as the other free end to form a lift loop 44. Lower shoulder strap 16 consists of a 40 mm wide webbing, of a material such as heavyweight polypropylene, removeably attached to connector ring 32a with a plastic snap clip 46 sewn to the one free end of lower shoulder strap 16. A plastic strap adjuster 50 provides lower shoulder strap 16 length adjustments. The top free end of lower shoulder strap 16 threads through male buckle ends 48b and 48c and terminates by threading to male buckle end 48a. A plastic tie ring 52 is sewn to lower shoulder strap 16 between strap adjuster 50 and male buckle end 48c. One free end of a 5 mm, nylon, lateral cord 54 is removably attached to connector ring 32b with a plastic snap clip 56. To provide for the transport of several fish, up to two additional fish sacks 58 can be connected to male buckle ends 48b and 48c already provided on common lower shoulder strap 16. FIGS. 3 and 4 show an additional fish sack 58 comprised of a sack 12 and upper shoulder strap 18. Connector rings 32a and 32b are included on the additional fish sack 58 to provide for fastening and securing of all sacks 12 together with a common lateral cord 54. Operation—FIGS. 1-4 FIG. 1 shows fish sack carrier 10 in its open position ready for use. Lower shoulder strap 16 is attached to either connector ring 32a or 32b depending on which shoulder the fisherman prefers to carry the fish. Lateral cord 54 is attached to the connector ring 32a or 32b that is on the opposite side of sack 12 and lower shoulder strap 16. Fish sack carrier 10 is used by inserting a fish head first into top opening 28 of sack 12. Cinch strap 30 is pulled snug around the girth of the fish and the tag end of cinch strap 30 is secured with the hook and loop fabric 34 to its main length. The user then closes top opening 28 of sack 12 by pulling and drawing upper shoulder strap 18. Shoulder pad 40 is adjusted to position by sliding along strap 36 toward sack top opening 28 exposing lift loop 44. Fish sack carrier 10 is now ready to be lifted upon the fisherman's shoulder. FIG. 2 shows fish sack carrier 10 in use. The fisherman inserts his hand through lift loop 44 and lifts fish sack carrier 10 over the shoulder positioning upper shoulder strap 18 on top of the shoulder with water-resistant sack fabric 22 against the fisherman's back and mesh fabric 24 outward. While continuing to hold lift loop 44 with one hand, the user reaches around his back with his other hand to grasp and connect lower shoulder strap 16 to upper shoulder strap 18 by inserting male buckle end 48a into female buckle end 42. The user pulls the tag end of lower shoulder strap 16 protruding from the bottom side of strap adjuster 50 to tighten fish sack carrier 10 to their back, shoulder, and chest. Lastly, the fisherman reaches around the opposite side of their body from lower shoulder strap 16 and grasps lateral cord 54 pulling it around their side and chest to attach with a knot to tie ring 52. This secures fish sack carrier 10 upon the fisherman's back for transporting. It is possible to insert additional fish into the same sack 12 if the fish are in combination smaller in girth than sack 12. A fish with a length longer than sack 12 can be carried with its tail extended outside top opening 28 of sack 12. Smaller fish can be carried using this method by drawing sack top opening 28 tightly around the fish tail. This keeps the fish weight as high up the back of the fisherman as possible, thus better stabilizing the fish and improving comfort. FIG. 3 shows an additional fish sack 58 that can be used to transport several fish simultaneously. A second and third fish sack 58 can be carried by connecting to male buckle ends 48b and 48c provided on the common lower shoulder strap 16. FIG. 4 is a perspective view of a fisherman wearing two fish sacks. To carry the second fish sack 58, the user lifts the second fish sack 58 upon the same shoulder as fish sack carrier 10. The female buckle end 42 on second fish sack 58 connects to second additional male buckle end 48b on lower shoulder strap 16. A third fish sack 58 can be installed using this same method and connecting to third male buckle end 48c on lower shoulder strap 16. The user then threads lateral cord 54 through connector rings 32a and 32b on additional fish sack 58 before attaching lateral cord 54 to tie ring 52. This secures the fish for transport. Sack 12 has a mesh fabric 24 front for cooling of the fish and draining of fluids. Fish sack carrier 10 can be immersed in water to keep the fish preserved. Mesh fabric 24 allows water circulation in sack 12. Lateral cord 54 can be used to tie and secure fish sack 12 in the water. After use, sack 12 can be cleaned by rinsing with water or machine-washing after removing lower strap 16. Fish sack carrier 10 can be folded or rolled up into a small, convenient, pocket size packet for storage and later use. CONCLUSION, RAMIFICATIONS, AND SCOPE OF INVENTION Accordingly, the reader will see that this invention provides for the wading or pedestrian fisherman a lightweight, durable, fish carrier device that can be easily operated and managed to comfortably and simultaneously transport one or several larger size fish such as salmon or steelhead, leaving both hands free to carry other objects. Furthermore, the fish sack carrier has the additional advantages in that: It permits a wide selection of materials to minimize the overall pack weight and to provide fish sack carriers of various quality and durability. It permits a wide selection of fabric and fastener color combinations. It permits several sack sizes to be manufactured tailored to the size or type of fish being sought. For instance, a slightly smaller sack could be produced for less mature salmon or steelhead. It permits the fish sack to be carried comfortably by hand with the carry loop integral to the upper shoulder strap, or held by hand with the fish sack over either shoulder with the lifting loop also integral to the upper shoulder strap. It permits the fish sack to be immersed in water to preserve the fish while continuing to fish. The lateral cord can be used as a stringer to tie to an object such as a log to secure the fish. While my above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. For example, a sack of the same general shape could be designed with a slightly different suspension system, to position the sack horizontally instead of vertically on the fisherman's back. This sack could be enlarged in height to allow transport of several fish stacked horizontally in the same sack. Additionally, a vertical positioned sack could be manufactured to provide for carrying several fish by enlarging the width of the sack and attaching a narrow strip of fabric on the inside of the sack and parallel to the entire length of the sack. This creates separate vertical cells, or partitions, each of which would enclose one fish. Cinch straps attached at predetermined locations on the outside of the sack and threaded through the sack could also be used to create the separate cells. Several other means are possible for creating the partitions in this sack design. Considerable modifications may be made to the preferred embodiment without departing from the principals of the invention. For example, additional cinch straps could be sewn at points along the length of the sack that would encircle the girth of the fish further stabilizing the fish in a vertical position. The upper shoulder strap could be removably attached to the sack and the section of strap passing through the sack top hem could be changed to a different construction such as rope. In addition, the size, color, and material of the straps, fasteners, and lateral cord could be changed. The selection and amount of fasteners could be changed. For example, the snap clips and connector rings could be made of metal or plastic. The lateral cord snap clip could be deleted and the cord tied directly to the sack connector ring to reduce cost. Deleting the interlocking buckles and snap clips could create a simpler, cheaper, one-piece shoulder strap. The sack seams could be adhesively bonded instead of sewn if vinyl surfaced fabric were utilized. Finally, a small area of the backside of the sack could be of mesh fabric to improve water circulation when the fish sack carrier is placed in the water, or, the mesh material could be deleted entirely. Accordingly, the scope of the invention should be determined not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents.
|
A
|
A01
|
A01K
|
97
|
20
|
|||
11840635
|
US20070287013A1-20071213
|
Aluminizing slurry Compositions Free of Hexavalent Chromium, and Related Methods and Articles
|
ACCEPTED
|
20071128
|
20071213
|
[]
|
C09D100
|
["C09D100", "B32B1520"]
|
7896962
|
20070817
|
20110301
|
106
|
600000
|
94929.0
|
MARCANTONI
|
PAUL
|
[{"inventor_name_last": "Kool", "inventor_name_first": "Lawrence", "inventor_city": "Clifton Park", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Gigliotti", "inventor_name_first": "Michael", "inventor_city": "Scotia", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Rutkowski", "inventor_name_first": "Stephen", "inventor_city": "Duanesburg", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Svec", "inventor_name_first": "Paul", "inventor_city": "Scotia", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Kogan", "inventor_name_first": "Anatoli", "inventor_city": "Clifton Park", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "DiDomizio", "inventor_name_first": "Richard", "inventor_city": "Latham", "inventor_state": "NY", "inventor_country": "US"}, {"inventor_name_last": "Noel", "inventor_name_first": "Brian", "inventor_city": "Morrow", "inventor_state": "OH", "inventor_country": "US"}, {"inventor_name_last": "Carr", "inventor_name_first": "David", "inventor_city": "Taylor", "inventor_state": "SC", "inventor_country": "US"}, {"inventor_name_last": "Thompson", "inventor_name_first": "William", "inventor_city": "Greenville", "inventor_state": "SC", "inventor_country": "US"}]
|
A slurry coating composition is described, which is very useful for enriching the surface region of a metal-based substrate with aluminum. The composition includes colloidal silica and particles of an aluminum-based powder, and is substantially free of hexavalent chromium. The slurry may include colloidal silica and an alloy of aluminum and silicon. Alternatively, the slurry includes colloidal silica, aluminum or aluminum-silicon, and an organic stabilizer such as glycerol. The slurry exhibits good thermal and chemical stability for extended periods of time, making it very useful for industrial applications. Related methods and articles are also described.
|
1. A slurry coating composition for providing aluminum content to the surface region of a metal-based substrate, wherein the composition is substantially free of hexavalent chromium, and comprises colloidal silica and particles of an aluminum-based powder. 2. The composition of claim 1, wherein the aluminum-based powder has an average particle size in the range of about 0.5 micron to about 200 microns. 3. The composition of claim 1, wherein the aluminum-based powder comprises an alloy of aluminum and silicon. 4. The composition of claim 3, wherein the silicon is present in an amount sufficient to decrease the melting point of the aluminum-silicon alloy to below about 610° C. 5. The composition of claim 3, wherein the silicon is present at a level in the range of about 1% by weight to about 20% by weight, based on the combined weight of the silicon and aluminum. 6. The composition of claim 5, wherein the silicon is present at a level in the range of about 10% by weight to about 15% by weight, based on the combined weight of the silicon and aluminum. 7. The composition of claim 3, wherein the aluminum-silicon alloy comprises substantially spherical powder particles. 8. The composition of claim 1, further comprising a liquid carrier selected from the group consisting of water, alcohols, halogenated hydrocarbon solvents, and compatible mixtures thereof. 9. The composition of claim 8, further comprising an effective amount of at least one additive selected from the group consisting of thickening agents, dispersants, deflocculants, anti-settling agents, anti-foaming agents, binders, plasticizers, emollients, surfactants, and lubricants. 10. The composition of claim 1, containing less than about 10% by weight of phosphoric acid and phosphoric acid derivatives, based on the weight of the entire composition. 11. An aqueous-based slurry coating composition according to claim 1. 12. The composition of claim 1, wherein the colloidal silica is present at a level in the range of about 5% by weight to about 20% by weight, based on silica solids as a percentage of the entire composition. 13. The composition of claim 1, wherein the amount of aluminum in the slurry composition exceeds the amount of aluminum present in the substrate by up to about 65 atomic %. 14. The composition of claim 1, wherein the aluminum-based powder further comprises at least one metal selected from the group consisting of platinum group metals, rare earth metals, scandium, yttrium, iron, chromium, and cobalt. 15. The composition of claim 1, wherein the silica in the colloidal silica has an average particle size in the range of about 10 nanometers to about 100 nanometers. 16. The composition of claim 1, further comprising at least one organic compound which contains at least two hydroxyl groups. 17. The composition of claim 16, wherein the organic compound contains at least three hydroxyl groups. 18. The composition of claim 16, wherein the organic compound is selected from the group consisting of alkane diols, glycerol, pentaerythritol, fats, and carbohydrates. 19. The composition of claim 18, wherein the carbohydrate is a sugar compound. 20. The composition of claim 16, wherein the organic compound is present in an amount sufficient to chemically stabilize the aluminum-based powder during contact with any aqueous component present in the composition. 21. The composition of claim 16, wherein the organic compound is present at a level in the range of about 0.1% by weight to about 20% by weight, based on the total weight of the composition. 22. A slurry coating composition for providing aluminum to the surface region of a turbine component formed from a material comprising a nickel-based superalloy, wherein the composition is substantially free of hexavalent chromium, and comprises colloidal silica and particles of an aluminum-silicon alloy which has an average particle size in the range of about 1 micron to about 50 microns. 23. The composition of claim 22, wherein the colloidal silica is present at a level in the range of about 5% by weight to about 20% by weight, based on silica solids as a percentage of the entire composition; and the amount of aluminum in the composition exceeds the amount of aluminum present in the surface region of the component by up to about 65 atomic %. 24. A slurry coating composition for providing aluminum to the surface region of a turbine component formed from a material comprising a nickel-based superalloy, wherein the composition is substantially free of hexavalent chromium, and comprises colloidal silica; an organic stabilizer which contains at least two hydroxyl groups; and particles of an aluminum-based powder which has an average particle size in the range of about 1 micron to about 50 microns. 25. The composition of claim 24, wherein the organic stabilizer is selected from the group consisting of glycerol, at least one dihydroxy alcohol, and combinations thereof. 26. The composition of claim 24, wherein the aluminum-based powder comprises an alloy of aluminum and silicon. 27. The composition of claim 24, wherein the organic stabilizer is present at a level in the range of about 0.1% by weight to about 20% by weight, based on the total weight of the composition; the colloidal silica is present at a level in the range of about 5% by weight to about 20% by weight, based on silica solids as a percentage of the entire composition; and the amount of aluminum in the composition exceeds the amount of aluminum present in the surface region of the component by up to about 65 atomic %. 28-39. (canceled) 40. A method for preparing an aluminum-based slurry coating composition, comprising the following steps: a) combining an organic stabilizer with an aluminum-based powder, in the presence of a limited amount of aqueous colloidal silica, so as to form a uniform, stabilizer-aluminum pre-blend, wherein the amount of aqueous colloidal silica present is high enough to ensure adequate blending of the stabilizer and the aluminum-based powder, but low enough to ensure that the pre-blend remains chemically-stabilized; and then b) combining a second portion of the aqueous colloidal silica with the stabilizer-aluminum pre-blend formed in step (a), to form a chemically-stable slurry coating composition. 41. A metal substrate, having a slurry coating disposed on its surface, said coating being free of hexavalent chromium, and comprising colloidal silica and particles of an aluminum-based powder. 42. The metal substrate of claim 41, wherein the aluminum-based powder comprises an alloy of aluminum and silicon. 43. The metal substrate of claim 41, wherein the slurry coating further comprises at least one organic compound which contains at least two hydroxyl groups. 44. The metal substrate of claim 41, comprising a turbine engine component formed of a nickel-based superalloy.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>This invention relates generally to coating systems for protecting metals. More specifically, it is directed to slurry coating compositions for providing aluminum enrichment to the surface region of a metal substrate. Many types of metals are used in industrial applications. When the application involves demanding operating conditions, specialty metals and alloys are often required. As an example, components within gas turbine engines operate in a high-temperature environment. The specialty alloys must withstand in-service temperatures in the range of about 650° C.-1200° C. Moreover, the alloys may be subjected to repeated temperature cycling, e.g., exposure to high temperatures, followed by cooling to room temperature, and then followed by rapid re-heating. In the case of turbine engines, the substrate is often formed from a nickel-base or cobalt-base superalloy. The term “superalloy” is usually intended to embrace complex cobalt- or nickel-based alloys which include one or more other elements such as aluminum, tungsten, molybdenum, titanium, and iron. The quantity of each element in the alloy is carefully controlled to impart specific characteristics, e.g., environmental resistance and mechanical properties such as high-temperature strength. Aluminum is a particularly important component for many superalloys. It imparts environmental resistance to the alloys, and can also improve their precipitation-strengthening. Superalloy substrates are often coated with protective metallic coatings. One example of the metallic coating is an MCrAl(X)-type material, where M is nickel, cobalt, or iron; and X is an element selected from the group consisting of Y, Ta, Si, Hf, Ti, Zr, B, C, and combinations thereof. Another type of protective metallic coating is an aluminide material, such as nickel-aluminide or platinum-nickel-aluminide. If the superalloy is exposed to an oxidizing atmosphere for an extended period of time, it can become depleted in aluminum. This is especially true when the particular superalloy component is used at the elevated temperatures described above. The aluminum loss can occur by way of various mechanisms. For example, aluminum can diffuse into the overlying protective coating; be consumed during oxidation of the protective coating; or be consumed during oxidation at the coating/substrate interface. Since loss of aluminum can be detrimental to the integrity of the superalloy, techniques for countering such a loss have been investigated. At elevated temperatures, the substrate can be partially replenished with aluminum which diffuses from an adjacent MCrAlX coating. However, the amount of aluminum diffusion into the substrate from the MCrAlX coating may be insufficient. One method for increasing the aluminum content of the superalloy substrate (i.e., in its surface region) is sometimes referred to in the art as “aluminiding” or “aluminizing”. In such a process, aluminum is introduced into the substrate by a variety of techniques. In the “pack aluminiding” process, the substrate is immersed within a mixture (or pack) containing the coating element source, filler material, and a halide activating agent. At high temperatures (usually about 700-750° C.), reactions within the mixture yield an aluminum-rich vapor which condenses onto the substrate surface. During a subsequent heat treatment, the condensed aluminum-based material diffuses into the substrate. Slurry compositions are employed in another method for incorporating aluminum into the surface of a superalloy. For example, an aqueous or organic slurry containing aluminum in some form can be sprayed or otherwise coated onto the substrate. The volatile components are then evaporated, and the aluminum-containing component can be heated in a manner which causes the aluminum to diffuse into the substrate surface. Important advantages are associated with using slurries for aluminizing the substrates. For example, slurries can be easily and economically prepared, and their aluminum content can be readily adjusted to meet the requirements for a particular substrate. Moreover, the slurries can be applied to the substrate by a number of different techniques, and their wetting ability helps to ensure relatively uniform aluminization. Slurry compositions which contain aluminum are described, for example, in U.S. Pat. No. 3,248,251 (Allen). The aluminum particulates in the patent are dispersed in an aqueous, acidic bonding solution which also contains metal chromate, dichromate or molybdate, and phosphate. (The phosphate serves as a binder). The chromate ions are known to improve corrosion resistance. One prevalent theory described in U.S. Pat. No. 6,074,464 is that the chromate ions passivate the bonding solution toward aluminum, and inhibit the oxidation of metallic aluminum. This allows particulate aluminum to be combined with the bonding solution, without the undesirable reaction between the solution and the aluminum. The coatings described in the Allen patent are known to very effectively protect some types of metal substrates from oxidation and corrosion, particularly at high temperatures. While the “Allen” compositions are useful for some applications, they have some disadvantages as well. One serious deficiency is that the compositions rely on the presence of chromates, which are considered toxic. In particular, hexavalent chromium is also considered to be a carcinogen. When compositions containing this form of chromium are used (e.g., in spray booths), special handling procedures have to be very closely followed, in order to satisfy health and safety regulations. The special handling procedures can often result in increased costs and decreased productivity. Attempts have been made to formulate slurry compositions which do not rely on the presence of chromates. For example, U.S. Pat. No. 6,150,033 describes chromate-free coating compositions which are used to protect metal substrates such as stainless steel. Many of the compositions are based on an aqueous phosphoric acid bonding solution, which comprises a source of magnesium, zinc, and borate ions. The coatings are said to be very satisfactory, in terms of oxidation- and corrosion resistance. However, the chromate-free slurry compositions may be accompanied by other serious drawbacks. For example, they are sometimes unstable over the course of several hours (or even several minutes), and may also generate unsuitable levels of gasses such as hydrogen. Furthermore, the compositions have been known to thicken or partially solidify during those time periods, making them very difficult to apply to a substrate, e.g., by spray techniques. Moreover, the use of phosphoric acid in the compositions may also contribute to their instability. This is especially true when chromate compounds are not present, since the latter apparently passivate the surface of the aluminum particles. In the absence of the chromates, any phosphoric acid present may attack the aluminum metal in the slurry composition, rendering it thermally and physically unstable. At best, such a slurry composition will be difficult to store and apply to a substrate. It is thus apparent that new slurry compositions useful for aluminizing metal substrates would be welcome in the art. The compositions should be capable of incorporating as much aluminum as necessary into the substrate. They should also be substantially free of chromate compounds—especially hexavalent chromium. (In some preferred embodiments, the compositions should also contain relatively low levels of phosphoric acid, e.g., less than about 10% by weight). Moreover, these improved slurry compositions should be chemically and physically stable for extended periods of use and storage, as compared to the prior art. They should also be amenable to slurry-application by various techniques, such as spraying, painting, and the like. Furthermore, the use of these compositions should be generally compatible with other techniques which might be used to treat a particular metal substrate, e.g., a superalloy component.
|
<SOH> BRIEF DESCRIPTION OF THE INVENTION <EOH>A slurry coating composition is described herein, which is very useful for enriching the surface region of a metal-based substrate with aluminum. The composition includes colloidal silica and particles of an aluminum-based powder. The aluminum-based powder usually has an average particle size in the range of about 0.5 micron to about 200 microns. (The powder is sometimes referred to herein as the “aluminum powder”, for the sake of brevity). The composition is substantially free of hexavalent chromium, and contains, at most, restricted amounts of phosphoric acid. In one embodiment, the slurry composition comprises colloidal silica and an alloy of aluminum and silicon. In another embodiment, the slurry composition comprises colloidal silica, aluminum or aluminum-silicon, and an organic stabilizer such as glycerol. The slurry composition is preferably aqueous, as defined below. The composition can be applied to the substrate by a number of techniques, but is often sprayed. As described below, the slurry composition exhibits good thermal and chemical stability for extended periods of time, making it very useful for industrial applications. Another embodiment is directed to a method for aluminiding the surface region of a metal substrate. The method includes the following steps, using the types of slurry coatings described below: (I) applying at least one layer of the slurry coating to the surface of the substrate; wherein the slurry coating is a composition which comprises colloidal silica and particles of an aluminum-based powder; and the aluminum-based powder has an average particle size in the range of about 0.5 micron to about 200 microns; and then (II) heat treating the slurry coating, under conditions sufficient to remove volatile components from the coating, and to cause diffusion of aluminum into the surface region of the substrate. Still another embodiment is directed to an article, e.g., a superalloy substrate like those present in turbine alloy components. The substrate is covered by the aluminum-containing slurry coating described herein. The slurry coating is free of hexavalent chromium, and can be heated to diffuse the aluminum into the surface region of the substrate. Other features and advantages of the present invention will be apparent from the following detailed description. detailed-description description="Detailed Description" end="lead"?
|
BACKGROUND OF THE INVENTION This invention relates generally to coating systems for protecting metals. More specifically, it is directed to slurry coating compositions for providing aluminum enrichment to the surface region of a metal substrate. Many types of metals are used in industrial applications. When the application involves demanding operating conditions, specialty metals and alloys are often required. As an example, components within gas turbine engines operate in a high-temperature environment. The specialty alloys must withstand in-service temperatures in the range of about 650° C.-1200° C. Moreover, the alloys may be subjected to repeated temperature cycling, e.g., exposure to high temperatures, followed by cooling to room temperature, and then followed by rapid re-heating. In the case of turbine engines, the substrate is often formed from a nickel-base or cobalt-base superalloy. The term “superalloy” is usually intended to embrace complex cobalt- or nickel-based alloys which include one or more other elements such as aluminum, tungsten, molybdenum, titanium, and iron. The quantity of each element in the alloy is carefully controlled to impart specific characteristics, e.g., environmental resistance and mechanical properties such as high-temperature strength. Aluminum is a particularly important component for many superalloys. It imparts environmental resistance to the alloys, and can also improve their precipitation-strengthening. Superalloy substrates are often coated with protective metallic coatings. One example of the metallic coating is an MCrAl(X)-type material, where M is nickel, cobalt, or iron; and X is an element selected from the group consisting of Y, Ta, Si, Hf, Ti, Zr, B, C, and combinations thereof. Another type of protective metallic coating is an aluminide material, such as nickel-aluminide or platinum-nickel-aluminide. If the superalloy is exposed to an oxidizing atmosphere for an extended period of time, it can become depleted in aluminum. This is especially true when the particular superalloy component is used at the elevated temperatures described above. The aluminum loss can occur by way of various mechanisms. For example, aluminum can diffuse into the overlying protective coating; be consumed during oxidation of the protective coating; or be consumed during oxidation at the coating/substrate interface. Since loss of aluminum can be detrimental to the integrity of the superalloy, techniques for countering such a loss have been investigated. At elevated temperatures, the substrate can be partially replenished with aluminum which diffuses from an adjacent MCrAlX coating. However, the amount of aluminum diffusion into the substrate from the MCrAlX coating may be insufficient. One method for increasing the aluminum content of the superalloy substrate (i.e., in its surface region) is sometimes referred to in the art as “aluminiding” or “aluminizing”. In such a process, aluminum is introduced into the substrate by a variety of techniques. In the “pack aluminiding” process, the substrate is immersed within a mixture (or pack) containing the coating element source, filler material, and a halide activating agent. At high temperatures (usually about 700-750° C.), reactions within the mixture yield an aluminum-rich vapor which condenses onto the substrate surface. During a subsequent heat treatment, the condensed aluminum-based material diffuses into the substrate. Slurry compositions are employed in another method for incorporating aluminum into the surface of a superalloy. For example, an aqueous or organic slurry containing aluminum in some form can be sprayed or otherwise coated onto the substrate. The volatile components are then evaporated, and the aluminum-containing component can be heated in a manner which causes the aluminum to diffuse into the substrate surface. Important advantages are associated with using slurries for aluminizing the substrates. For example, slurries can be easily and economically prepared, and their aluminum content can be readily adjusted to meet the requirements for a particular substrate. Moreover, the slurries can be applied to the substrate by a number of different techniques, and their wetting ability helps to ensure relatively uniform aluminization. Slurry compositions which contain aluminum are described, for example, in U.S. Pat. No. 3,248,251 (Allen). The aluminum particulates in the patent are dispersed in an aqueous, acidic bonding solution which also contains metal chromate, dichromate or molybdate, and phosphate. (The phosphate serves as a binder). The chromate ions are known to improve corrosion resistance. One prevalent theory described in U.S. Pat. No. 6,074,464 is that the chromate ions passivate the bonding solution toward aluminum, and inhibit the oxidation of metallic aluminum. This allows particulate aluminum to be combined with the bonding solution, without the undesirable reaction between the solution and the aluminum. The coatings described in the Allen patent are known to very effectively protect some types of metal substrates from oxidation and corrosion, particularly at high temperatures. While the “Allen” compositions are useful for some applications, they have some disadvantages as well. One serious deficiency is that the compositions rely on the presence of chromates, which are considered toxic. In particular, hexavalent chromium is also considered to be a carcinogen. When compositions containing this form of chromium are used (e.g., in spray booths), special handling procedures have to be very closely followed, in order to satisfy health and safety regulations. The special handling procedures can often result in increased costs and decreased productivity. Attempts have been made to formulate slurry compositions which do not rely on the presence of chromates. For example, U.S. Pat. No. 6,150,033 describes chromate-free coating compositions which are used to protect metal substrates such as stainless steel. Many of the compositions are based on an aqueous phosphoric acid bonding solution, which comprises a source of magnesium, zinc, and borate ions. The coatings are said to be very satisfactory, in terms of oxidation- and corrosion resistance. However, the chromate-free slurry compositions may be accompanied by other serious drawbacks. For example, they are sometimes unstable over the course of several hours (or even several minutes), and may also generate unsuitable levels of gasses such as hydrogen. Furthermore, the compositions have been known to thicken or partially solidify during those time periods, making them very difficult to apply to a substrate, e.g., by spray techniques. Moreover, the use of phosphoric acid in the compositions may also contribute to their instability. This is especially true when chromate compounds are not present, since the latter apparently passivate the surface of the aluminum particles. In the absence of the chromates, any phosphoric acid present may attack the aluminum metal in the slurry composition, rendering it thermally and physically unstable. At best, such a slurry composition will be difficult to store and apply to a substrate. It is thus apparent that new slurry compositions useful for aluminizing metal substrates would be welcome in the art. The compositions should be capable of incorporating as much aluminum as necessary into the substrate. They should also be substantially free of chromate compounds—especially hexavalent chromium. (In some preferred embodiments, the compositions should also contain relatively low levels of phosphoric acid, e.g., less than about 10% by weight). Moreover, these improved slurry compositions should be chemically and physically stable for extended periods of use and storage, as compared to the prior art. They should also be amenable to slurry-application by various techniques, such as spraying, painting, and the like. Furthermore, the use of these compositions should be generally compatible with other techniques which might be used to treat a particular metal substrate, e.g., a superalloy component. BRIEF DESCRIPTION OF THE INVENTION A slurry coating composition is described herein, which is very useful for enriching the surface region of a metal-based substrate with aluminum. The composition includes colloidal silica and particles of an aluminum-based powder. The aluminum-based powder usually has an average particle size in the range of about 0.5 micron to about 200 microns. (The powder is sometimes referred to herein as the “aluminum powder”, for the sake of brevity). The composition is substantially free of hexavalent chromium, and contains, at most, restricted amounts of phosphoric acid. In one embodiment, the slurry composition comprises colloidal silica and an alloy of aluminum and silicon. In another embodiment, the slurry composition comprises colloidal silica, aluminum or aluminum-silicon, and an organic stabilizer such as glycerol. The slurry composition is preferably aqueous, as defined below. The composition can be applied to the substrate by a number of techniques, but is often sprayed. As described below, the slurry composition exhibits good thermal and chemical stability for extended periods of time, making it very useful for industrial applications. Another embodiment is directed to a method for aluminiding the surface region of a metal substrate. The method includes the following steps, using the types of slurry coatings described below: (I) applying at least one layer of the slurry coating to the surface of the substrate; wherein the slurry coating is a composition which comprises colloidal silica and particles of an aluminum-based powder; and the aluminum-based powder has an average particle size in the range of about 0.5 micron to about 200 microns; and then (II) heat treating the slurry coating, under conditions sufficient to remove volatile components from the coating, and to cause diffusion of aluminum into the surface region of the substrate. Still another embodiment is directed to an article, e.g., a superalloy substrate like those present in turbine alloy components. The substrate is covered by the aluminum-containing slurry coating described herein. The slurry coating is free of hexavalent chromium, and can be heated to diffuse the aluminum into the surface region of the substrate. Other features and advantages of the present invention will be apparent from the following detailed description. DETAILED DESCRIPTION OF THE INVENTION As mentioned above, the slurry coating composition includes colloidal silica. The term “colloidal silica” is meant to embrace any dispersion of fine particles of silica in a medium of water or another solvent. (Water is usually preferred). Dispersions of colloidal silica are available from various chemical manufacturers, in either acidic or basic form. Moreover, various shapes of silica particles can be used, e.g., spherical, hollow, porous, rod, plate, flake, or fibrous, as well as amorphous silica powder. Spherical silica particles are often preferred. The particles usually (but not always) have an average particle size in the range of about 10 nanometers to about 100 nanometers. Non-limiting examples of references which describe colloidal silica are U.S. Pat. No. 4,027,073 and U.S. Pat. No. 5,318,850, which are incorporated herein by reference. Commercial examples of colloidal silica can be found under the trade names Ludox® and Remasol® (e.g., from Remet® Corporation, Utica, N.Y.). The amount of colloidal silica present in the composition will depend on various factors. They include, for example: the amount of aluminum powder being used; and the presence (and amount) of an organic stabilizer, as described below. (It appears that the colloidal silica functions primarily as a very effective binder). Processing conditions are also a consideration, e.g., how the slurry is formed and applied to a substrate. Usually, the colloidal silica is present at a level in the range of about 5% by weight to about 20% by weight, based on silica solids as a percentage of the entire composition. In especially preferred embodiments, the amount is in the range of about 10% by weight to about 15% by weight. The slurry coating composition further includes aluminum powder. This powder serves as the source of aluminum for the substrate. The aluminum powder can be obtained from a number of commercial sources, such as Valimet Corporation, Stockton, Calif. The powder is usually in the form of spherical particles. However, it can be in other forms as well, such as those described above for the colloidal silica, or in the form of a wire, e.g., wire mesh. The aluminum powder can be used in a variety of standard sizes. The size of the powder particles will depend on several factors, such as the type of substrate; the technique by which the slurry is to be applied to the substrate; the identity of the other components present in the slurry; and the relative amounts of those components. Usually, the powder particles have an average particle size in the range of about 0.5 micron to about 200 microns. In some preferred embodiments, the powder particles have an average particle size in the range of about 1 micron to about 50 microns. In especially preferred embodiments, the average particle size is in the range of about 1 micron to about 20 microns. The powder particles are often produced by a gas atomization process, although other techniques can be employed, e.g., rotating electrode techniques. As used herein, an “aluminum-based powder” is defined as one which contains at least about 75% by weight aluminum, based on total elements present. Thus, the powder may contain other elements which impart various characteristics to the substrate material, e.g., enhanced oxidation resistance, phase stability, environmental resistance, and sulfidation resistance. For example, the powder may contain at least one platinum group metal, such as platinum, palladium, ruthenium, rhodium, osmium, and iridium. Rare earth metals are also possible, e.g., lanthanides such as lanthanum, cerium, and erbium. Elements which are chemically-similar to the lanthanides could also be included, such as scandium and yttrium. In some instances, it may also be desirable to include one or more of iron, chromium, and cobalt. Moreover, those skilled in the art understand that aluminum powder may also contain various other elements and other materials at impurity levels, e.g., less than about 1% by weight. Techniques for preparing powders formed from any combination of the optional elements described above are also well-known in the art. The composition of the aluminum-based powder, and the composition of the slurry, depend in large part on the amount of aluminum needed for the substrate. In general, the aluminum in the slurry coating composition will be present in an amount sufficient to compensate for any projected loss of aluminum from the substrate, under projected operating conditions. The operating condition parameters include temperature levels, temperature/time schedules and cycles; and environmental conditions. Data regarding loss of aluminum from a typical metal substrate exposed to the operating conditions of interest is readily obtainable, as described, for example, in U.S. Pat. No. 6,372,299 (A. M. Thompson et al). This patent is incorporated herein by reference. Frequently, the amount of aluminum in the slurry composition is calculated to exceed the amount of aluminum present in the substrate itself (i.e., as formed) by up to about 65 atomic %. In terms of weight percentages, the amount of aluminum in the slurry is often in the range of about 0.5% by weight to about 45% by weight. In preferred embodiments, the amount of aluminum is in the range of about 30% by weight to about 40% by weight. (Depending on the particular requirements for the substrate, i.e., its surface region, these aluminum levels may be adjusted to allow for the presence of other metals intended for diffusion, as described herein). In one embodiment of this invention, the aluminum is present in the form of an aluminum-silicon alloy. Frequently, the alloy is in powder form, and is available from companies like Valimet Corporation. Alloy powders of this type usually have a particle size in the range described above for the aluminum powders. They are often formed from a gas atomization process, as mentioned previously. The silicon in the aluminum-silicon alloy serves, in part, to decrease the melting point of the alloy, thereby facilitating the aluminiding process, as described below. (It also appears that the silicon functions as a passivating agent, so that the alloy is relatively stable in the presence of the colloidal silica. However, the inventors do not wish to be bound by this theory). In some embodiments, the silicon is present in an amount sufficient to decrease the melting point of the alloy to below about 610° C. Usually, the silicon is present in the alloy at a level in the range of about 1% by weight to about 20% by weight, based on the combined weight of the silicon and aluminum. In some preferred embodiments, the silicon is present at a level in the range of about 10% by weight to about 15% by weight. Table 1 describes some of the chemical and physical characteristics for several commercial grades of spherical, aluminum-silicon particles, available from Valimet Corporation. These grades of the aluminum-silicon alloy are merely exemplary, since many other types of these alloys could be used. TABLE 1 WEIGHT % S-10 GRADE S-20 GRADE Aluminum Balance Balance Silicon 11.0%-13.0% 11.0%-13.0% Iron 0.8% maximum 0.8% maximum Zinc 0.2% maximum 0.2% maximum Oil and Grease 0.2% maximum 0.2% maximum Volatile Components 0.1% maximum 0.1% maximum SIEVE ANALYSIS +140 1.0% maximum +170 7.0% maximum +200 0.1% maximum +250 1.0% maximum +325 15.0% maximum 90.0% minimum −325 85.0% minimum 10.0% maximum As in the case of the powders described above, the aluminum-silicon alloys may also contain one or more other elements which impart a variety of desired characteristics. Examples include the platinum group metals; rare earth metals (as well as Sc and Y); iron, chromium, cobalt, and the like. Minor amounts of impurities are also sometimes present, as described previously. In another embodiment, the slurry composition includes an organic stabilizer, in addition to the colloidal silica and the aluminum (or aluminum-silicon) component. The stabilizer is an organic compound which contains at least two hydroxyl groups. In some preferred embodiments, the stabilizer contains at least three hydroxyl groups. Stabilizers which are water-miscible are also sometimes preferred, although this is often not a critical requirement. Moreover, a combination of two or more organic compounds could be used as the stabilizer. Many organic compounds can be used. Non-limiting examples include alkane diols (sometimes referred to as “dihydroxy alcohols”) such as ethanediol, propanediol, butanediol, and cyclopentanediol. (Some of these dihydroxy alcohols are referred to as “glycols”, e.g., ethylene glycol, propylene glycol, and diethylene glycol). The diols can be substituted with various organic groups, i.e., alkyl or aromatic groups. Non-limiting examples of the substituted versions include 2-methyl-1,2-propanediol; 2,3-dimethyl-2,3-butanediol; 1-phenyl-1,2-ethanediol; and 1-phenyl-1,2-propanediol. Another example of the organic stabilizer is glycerol, C3H5(OH)3. The compound is sometimes referred to as “glycerin” or “glycerine”. Glycerol can readily be obtained from fats, i.e., glycerides. Compounds containing greater than three hydroxy groups (some of which are referred to as “sugar alcohols”) can also be used. As an example, pentaerythritol, C(CH2OH)4, can be a suitable stabilizer. Sorbitol and similar polyhydroxy alcohols represent other examples. Suitable compounds are also described in many standard texts. Examples include “Organic Chemistry”, by Morrison and Boyd, 3rd Edition (1975); and “The Condensed Chemical Dictionary”, Tenth Edition, Van Nostrand Reinhold Company (1981). Various polymeric materials containing at least two hydroxy groups can also be employed as the organic stabilizer. Non-limiting examples include various fats (glycerides), such as phosphatidic acid (a phosphoglyceride). Carbohydrates represent another broad class of materials that may be employed. They are well-known in the art and described, for example, in the “Organic Chemistry” text mentioned above, pages 1070-1132. The term “carbohydrate” is meant to include polyhydroxy aldehydes, polyhydroxy ketones, or compounds that can be hydrolyzed to them. The term includes materials like lactose, along with sugars, such as glucose, sucrose, and fructose. Many related compounds could also be used, e.g., polysaccharides like cellulose and starch, or components within the polysaccharides, such as amylose. (Water-soluble derivatives of any of these compounds are also known in the art, and can be used herein). Based on factors such as cost, availability, and effectiveness, glycerols and dihydroxy alcohols like the glycols are often preferred as the organic stabilizer. Although the inventors do not wish to be bound by any specific theory, it appears that the tri-hydroxy functionality of compounds like glycerol is especially effective at passivating the aluminum component in the slurry. (Compounds like glycerol, which contain three or more hydroxy groups, are sometimes referred to as “polyols”). The amount of the organic stabilizer which should be used will depend on various factors. They include: the specific type of stabilizer present; the hydroxyl content of the stabilizer; its water-miscibility; the effect of the stabilizer on the viscosity of the slurry composition; the amount of aluminum present in the slurry composition; the particle size of the aluminum; the surface-to-volume ratio of the aluminum particles; the specific technique used to prepare the slurry; and the identity of the other components which may be present in the slurry composition. (For example, if used in sufficient quantities, the organic stabilizer is capable of preventing or minimizing any undesirable reaction between the aluminum metal and phosphoric acid, when the latter is present). In preferred embodiments, the organic stabilizer is present in an amount sufficient to chemically stabilize the aluminum or aluminum-silicon component during contact with water or any other aqueous components. The term “chemically stabilize” is used herein to indicate that the slurry remains substantially free of undesirable chemical reactions. These are reactions which would increase the viscosity and/or the temperature of the composition to unacceptable levels. For example, unacceptable increases in temperature or viscosity are those which could prevent the slurry composition from being easily applied to the substrate, e.g., by spraying. As a very general guideline, compositions which are deemed to be unstable are those which exhibit a temperature increase of greater than about 10 degrees Centigrade within about 1 minute, or greater than about 30 degrees Centigrade within about 10 minutes. In the alternative (or in conjunction with the temperature increase), these compositions may also exhibit unacceptable increases in viscosity over the same time period. (As those skilled in the chemical arts understand, the increases in temperature and viscosity may begin to occur after a short induction period). Usually, the amount of organic stabilizer present in the slurry composition is in the range of about 0.1% by weight to about 20% by weight, based on the total weight of the composition. In preferred embodiments, the range is about 0.5% by weight to about 15% by weight. The slurry coating which contains the components described above can contain various other ingredients as well. Many of these are known in the art to those involved in slurry preparations. Slurries are generally described in “Kirk-Othmer's Encyclopedia of Chemical Technology”, 3rd Edition, Vol. 15, p. 257 (1981), and in the 4th Edition, Vol. 5, pp. 615-617 (1993), as well as in U.S. Pat. Nos. 5,759,932 and 5,043,378. Each of these references is incorporated herein by reference. A good quality slurry is usually well-dispersed and free of air bubbles and foaming. It typically has a high specific gravity and good rheological properties adjusted in accordance with the requirements for the particular technique used to apply the slurry to the substrate. Moreover, the solid particle settling rate in the slurry should be as low as possible, or should be capable of being controlled, e.g., by stirring. The slurry should also be chemically stable. As mentioned above, the slurry composition is preferably aqueous. In other words, it includes a liquid carrier which is primarily water, i.e., the medium in which the colloidal silica is often employed. As used herein, “aqueous” refers to compositions in which at least about 65% of the volatile components are water. Preferably, at least about 80% of the volatile components are water. Thus, a limited amount of other liquids may be used in admixture with the water. Non-limiting examples of the other liquids or “carriers” include alcohols, e.g., lower alcohols with 1-4 carbon atoms in the main chain, such as ethanol. Halogenated hydrocarbon solvents are another example. Selection of a particular carrier composition will depend on various factors, such as: the evaporation rate required during treatment of the substrate with the slurry; the effect of the carrier on the adhesion of the slurry to the substrate; the solubility of additives and other components in the carrier; the “dispersability” of powders in the carrier; the carrier's ability to wet the substrate and modify the rheology of the slurry composition; as well as handling requirements; cost requirements; and environmental/safety concerns. Those of ordinary skill in the art can select the most appropriate carrier composition by considering these factors. The amount of liquid carrier employed is usually the minimum amount sufficient to keep the solid components of the slurry in suspension. Amounts greater than that level may be used to adjust the viscosity of the slurry composition, depending on the technique used to apply the composition to a substrate. In general, the liquid carrier will comprise about 30% by weight to about 70% by weight of the entire slurry composition. (It should be noted that the slurry could be in the form of a “liquid-liquid emulsion”). A variety of other components may be used in the slurry coating composition. Most of them are well-known in areas of chemical processing and ceramics processing. Non-limiting examples of these additives are thickening agents, dispersants, deflocculants, anti-settling agents, anti-foaming agents, binders, plasticizers, emollients, surfactants, and lubricants. In general, the additives are used at a level in the range of about 0.01% by weight to about 10% by weight, based on the weight of the entire composition. For embodiments in which the slurry composition is based on colloidal silica and the aluminum-silicon alloy, there are no critical steps in preparing the composition. Conventional blending equipment can be used, and the shearing viscosity can be adjusted by addition of the liquid carrier. Mixing of the ingredients can be undertaken at room temperature, or at temperatures up to about 60° C., e.g., using a hot water bath or other technique. Mixing is carried out until the resulting blend is uniform. (Portions of the primary ingredients may be withheld temporarily during the blending operation, to ensure intimate mixing). The additives mentioned above, if used, are usually added after the primary ingredients have been mixed, although this will depend in part on the nature of the additive. For embodiments which utilize an organic stabilizer in conjunction with the aluminum-based powder and the colloidal silica, certain blending sequences are highly preferred in some instances. For example, the organic stabilizer is usually first mixed with the aluminum-based powder, prior to any significant contact between the aluminum-based powder and the aqueous carrier. A limited portion of the colloidal silica, e.g., one-half or less of the formulated amount, may also be included at this time (and added slowly), to enhance the shear characteristics of the mixture. The present inventors have discovered that the initial contact between the stabilizer and the aluminum, in the absence of a substantial amount of any aqueous component, greatly increases the stability of this type of slurry composition. The remaining portion of the colloidal silica is then added and thoroughly mixed into the blend. The other optional additives can also be added at this time. In some instances, it may be desirable to wait for a period of time, e.g., up to about 24 hours or more, prior to adding the remaining colloidal silica. This waiting period may enhance the “wetting” of the alumina with the stabilizer, but does not always appear to be necessary. Those skilled in the art can determine the effect of the waiting period on slurry stability, without undue experimentation. Blending temperatures are as described above. The sequence discussed above is very preferable for compositions which utilize the stabilizer. However, other techniques for mixing the ingredients may be possible. For example, if all of the primary ingredients are mixed together rapidly, then adverse reactions between the aluminum component and the colloidal silica could be prevented or minimized. However, the process should be monitored very closely for the occurrence of sudden increases in temperature and/or viscosity. Appropriate safeguards should be in place. The slurry coating composition may be applied to various metal substrates. The use of this composition is especially advantageous for enhancing the aluminum content of superalloy substrates. The term “superalloy” is usually intended to embrace complex cobalt-, nickel-, or iron-based alloys which include one or more other elements, such as chromium, rhenium, aluminum, tungsten, molybdenum, and titanium. Superalloys are described in many references, e.g., U.S. Pat. No. 5,399,313, incorporated herein by reference. High temperature alloys are also generally described in “Kirk-Othmer's Encyclopedia of Chemical Technology”, 3rd Edition, Vol. 12, pp. 417-479 (1980), and Vol. 15, pp. 787-800 (1981). The actual configuration of the substrate may vary widely. For example, the substrate may be in the form of various turbine engine parts, such as combustor liners, combustor domes, shrouds, buckets, blades, nozzles, or vanes. The slurry coatings can be applied to the substrate by a variety of techniques known in the art. Some examples of the deposition techniques are described in “Kirk-Othmer's Encyclopedia of Chemical Technology”, 4th Edition, Vol. 5, pp. 606-619 (1993). The slurries can be slip-cast, brush-painted, dipped, sprayed, poured, rolled, or spun-coated onto the substrate surface, for example. Spray-coating is often the easiest way to apply the slurry coating to substrates such as airfoils. The viscosity of the coating can be readily adjusted for spraying, by varying the amount of liquid carrier used. Spraying equipment is well-known in the art. Any spray gun for painting should be suitable, including manual or automated spray gun models; air-spray and gravity-fed models, and the like. Non-limiting examples are described in U.S. Pat. No. 6,086,997, incorporated herein by reference. Examples of commercially-available spray equipment carry the trade names Binks, Grayco, DeVilbiss, and Paasche. Adjustment in various spray gun settings (e.g., for pressure and slurry volume) can readily be made to satisfy the needs of a specific slurry-spraying operation. The slurry can be applied as one layer, or multiple layers. (Multiple layers may sometimes be required to deliver the desired amount of aluminum to the substrate). If a series of layers is used, a heat treatment can be performed after each layer is deposited, to accelerate removal of the volatile components. After the full thickness of the slurry has been applied, an additional, optional heat treatment may be carried out, to further remove volatile materials like the organic solvents and water. The heat treatment conditions will depend in part on the identity of the volatile components in the slurry. An exemplary heating regimen is about 5 minutes to about 120 minutes, at a temperature in the range of about 80° C. to about 200° C. (Longer heating times can compensate for lower heating temperatures, and vice versa). The dried slurry is then heated to a temperature sufficient to diffuse the aluminum into the surface region of the substrate, i.e., into the entire surface region, or some portion thereof. As used herein, the “surface region” usually extends to a depth of about 200 microns into the surface, and more frequently, to a depth of about 75 microns into the surface. Those of skill in the art understand that an “aluminum-diffused surface region” for substrates like superalloys includes both an aluminum-enriched region closest to the surface, and an area of aluminum-superalloy interdiffusion immediately below the enriched region. The temperature required for this aluminizing step (i.e., the diffusion temperature) will depend on various factors. They include: the composition of the substrate; the specific composition and thickness of the slurry; and the desired depth of enhanced aluminum concentration. Usually the diffusion temperature is within the range of about 650° C. to about 1100° C., and preferably, about 800° C. to about 950° C. These temperatures are also high enough to completely remove (by vaporization or pyrolysis) any organic compounds which are present, e.g., stabilizers like glycerol. The diffusion heat treatment can be carried out by any convenient technique, e.g., heating in an oven in a vacuum or under argon gas. The time required for the diffusion heat treatment will depend on many of the factors described above. Generally, the time will range from about 30 minutes to about 8 hours. In some instances, a graduated heat treatment is desirable. As a very general example, the temperature could be raised to about 650° C., held there for a period of time, and then increased, in steps, to about to 850° C. Alternatively, the temperature could initially be raised to a threshold temperature like 650° C., and then raised continuously, e.g., 1° C. per minute, to reach a temperature of about 850° C. in 200 minutes. Those skilled in the general art (e.g., those who work in the area of pack-aluminizing) will be able to select the most appropriate time-temperature regimen for a given substrate and slurry. EXAMPLES The examples which follow are merely illustrative, and should not be construed to be any sort of limitation on the scope of the claimed invention. Example 1 Sample A was a commercial slurry, outside the scope of the present invention. The slurry contained three primary components. The first component was an aluminum alloy powder which included silicon, and which had an average particle size of about 4 microns. The second component was chromic acid, while the third component was phosphoric acid. The acidic mixture comprised approximately 58% by weight of the total slurry. The chromic acid was in the form of a solution of chromium trioxide (CrO3) and water. When incorporated into the slurry, the chromium exists in its hexavalent state, and the color of the solution ranges from orange to deep red, depending on the concentration of the metal. When aluminum is added to the acidic solution, the chromium is slowly reduced to its trivalent state (Cr2O3), resulting in a distinctive green color. Sample B was a trial slurry material, also outside the scope of this invention. It was prepared by combining aluminum powder (4 micron average particle size) with 4 mL of orthophosphoric acid. The material did not contain any chromium component. Sample A exhibited a relatively high degree of stability, i.e., exhibiting substantially no change in viscosity, intrinsic temperature, or appearance. (The sample had previously been stable for more than one year). In marked contrast, sample B was immediately unstable upon preparation. A reaction occurred after the ingredients were mixed, resulting in a temperature increase, from room temperature to more than 100° C., in less than one minute. As the reaction proceeded, a mushroom cloud of gray reactant rose over the top of the container and overflowed. Upon cooling, the remaining product was very tacky, with no evidence of the presence of aluminum. This example demonstrates the necessity of including some form of chromium as a passivating agent in aluminum-based slurries of the prior art. Example 2 Samples C and D were aluminum-containing slurries which were free of any chromium component. The samples are outside the scope of the present invention, and were prepared according to the teachings of U.S. Pat. No. 6,368,394. The components for each sample are listed in Table 2: TABLE 2 Ingredient Sample C Sample D Deionized Water 40.0 mL 40.0 mL Phosphoric Acid (85%) 6.70 mL 9.20 mL Boron Oxide 0.85 g 1.40 g Aluminum Hydroxide 4.10 g 4.30 g Zinc Oxide — 0.70 g For each sample, the ingredients listed above were combined, with stirring, to form suspensions. 10 mL of each suspension (slurry) was combined with 8 g of aluminum powder, having an average particle size of about 4 microns. After 6.5 minutes of standing, slurry C exhibited a significant temperature change, reaching 180° C. at the 8 minute mark. Sample D was audibly “fizzing” about 1 minute after the addition of the aluminum. Nine minutes after being mixed, sample D began to increase in temperature rapidly, reaching 140° C. at the 10 minute mark. Sample D was still fizzing 20 minutes after being mixed. It was therefore apparent that both samples underwent significant reaction when the binding solution (phosphoric acid) was combined with the aluminum. The fact that both samples were made in small quantities leads one to predict that larger batches would probably produce more severe reactions, with more gas- and heat-generation. Neither slurry produced the mushroom cloud or tacky reaction product which occurred with sample B (Example 1). However, each sample had completely solidified in its container, after sitting overnight. Four hours after mixing, sample D had significantly increased in viscosity. 10 mL of water were added to the sample, causing more bubbles and fizzing. Both of the samples were then allowed to sit for about one hour. Following that rest period, each sample was stirred again, and then applied with a paint brush to coupons formed from a nickel-based superalloy. (The coupons had previously been grit-blasted and washed with alcohol). Both samples exhibited a very acceptable viscosity for painting, and initially adhered well to the coupon. The samples were then allowed to air-dry overnight. The samples were then cured, according to a three-step heating regimen: 60 minutes at 80° C.; then 30 minutes at 120° C.; followed by 60 minutes at 230° C. This curing cycle appeared to remove substantially all of the liquid material in each sample. Both samples were then heat-treated in a vacuum, using the following heat treatment cycle: 1) Load each coupon into oven, slurry-side up; 2) Raise oven temperature to 650° C. (±5° C.), and hold for 15 minutes (±1 minute); 3) Increase temperature at 8° C. per minute (maximum rate), to 870° C. (±5° C.); 4) Hold at 870° C. (±5° C.) for 2 hours (±6 minutes); and 5) Furnace-cool each coupon. Upon being removed from the oven, most of sample C was attached to the coupon. However, most of sample D had spalled off its coupon. There was thus a considerable difference in the final appearance of sample C, as compared to sample D. It appeared that the addition of zinc oxide to sample D adversely affected its high-temperature binding properties. After the heat treatment, each sample (i.e., the coated coupon) was cross-sectioned to produce additional samples for optical analysis. Cross-sectional portions of sample C showed very little diffusion of the aluminum from the sample into the coupon, i.e., the substrate. However, sample D did exhibit a significant diffusion zone (about 75 microns into the coupon), even though a significant portion of the sample had lost its slurry coating through spallation. In each instance, it may be possible to prevent some of the spallation by using thinner slurry coatings. The thinner coatings may be able to better withstand the effects of the heat treatment process, and could possibly allow for better diffusion characteristics. Additional, brief, short-term tests were conducted, in an attempt to assess the stability of these prior art, chromate-free compositions. In the first test, aluminum powder was simply combined with water in a container. Heat evolution was apparent within several hours. The material completely solidified in three days. Another washing procedure was used in a second test. In this instance, aluminum powder was washed in chromic acid, decanted, and then placed in phosphoric acid. The mixture reacted violently within 5 minutes. In a third informal experiment, aluminum powder was mixed with phosphoric acid, and chromic acid was very quickly added to the mixture. The mixture appeared to be stable for approximately 1 week, after which the test was discontinued. It is evident that the currently-known, chromate-free slurry compositions usually exhibit serious stability problems. Moreover, it can be difficult to apply the compositions to a substrate, and to maintain an adherent layer of the composition on the substrate during a heat treatment. Furthermore, the compositions may not be consistently capable of providing aluminum to the diffusion region of the substrate by way of a diffusion heat treatment. Example 3 Sample E was a slurry composition within the scope of the present invention. The colloidal silica was Remasol® grade LP-30, having a concentration of 30% SiO2 in water, with a particle size of 12-13 millimicrons. An aluminum-silicon alloy obtained from Read Chemical Company was also used: grade S-10. As described in Table 1, this material contained 11-13% silicon. The average particle size was about 10 microns. 30 weight % of the LP-30 silica and 70 weight % of the aluminum-silicon alloy was added to a mixing vessel, and mixed at high speed for about 15 minutes. The resulting slurry was very stable, and did not exhibit any significant increase in temperature or viscosity after combination of the ingredients. (The material was mixed immediately before use, because settling can occur quickly). The slurry was brushed onto the surface of a nickel-based superalloy coupon, using a paint brush. (The coupon had been previously grit-blasted and washed with alcohol). Two coats were applied, for a total thickness (wet) of about 125 microns. The slurry was allowed to air-dry on the coupon. After being air-dried, the coated coupon was cured in an oven, according to this heating regimen: 80° C. for 30 minutes, followed by 260° C. for 30 minutes. The coated coupon was then diffusion heat-treated in a vacuum oven, at a temperature of about 870° C. The coupon was held at that temperature for 2 hours. There was no evidence of coating spallation. After being oven-cooled, the coupon was cross-sectioned for analysis. The cross-section was examined by both light microscopy and scanning electron microscopy. The cross-section revealed an aluminum-enriched region on the surface of the coupon. The depth of the aluminum-enriched region was about 75 microns, as measured prior to the mechanical removal of any friable residue left behind after the heat treatment. The depth included an outer, “high-aluminum” region, and an inner region of aluminum-superalloy interdiffusion. Other slurry compositions having the same contents as sample E were stored and monitored for stability. The compositions remained stable for at least 5 months, i.e., as long as monitoring had taken place. Example 4 Sample F was a slurry composition within the scope of the present invention. The colloidal silica used in Example 3 was used here as well. In this example, an aluminum powder (obtained from Alfa Aesar) was used, rather than the aluminum-silicon alloy powder. The aluminum powder had an average particle size of about 10 microns. Moreover, in this experiment, glycerol (glycerine) was used as an organic stabilizer. The overall composition of the slurry was as follows: 32 weight % of the LP-30 colloidal silica; 60 weight % of the aluminum powder, and 8 weight percent of the glycerol. (In one example, the actual ingredients were as follows: 32 g LP-30; 60 g aluminum powder; and 8 g glycerine). The glycerol was combined with one-half of the formulated amount of LP-30 (i.e., 16 weight percent), and mixed for about 5 minutes. The aluminum powder was then added to the mixture, followed by additional mixing. A planetary mixer was used, and mixing was continued until a uniform paste was present. The remaining portion of LP-30 was then added, followed by mixing at high speed, using an air-driven drill press mixer. As in the case of sample E, the slurry was very stable, and did not exhibit any significant increase in temperature or viscosity after combination of the ingredients. (The material was mixed immediately before use, to prevent settling). In this example, the slurry was air-sprayed onto the surface of a pre-treated, nickel-based superalloy coupon, using a conventional DeVilbiss spray gun. The average thickness (wet) was about 125 microns. The slurry was then allowed to air-dry on the coupon. Following air-drying, the slurry was then cured in an oven, according to the same heating regimen described in Example 3. The coated coupon was then diffusion heat-treated in a vacuum oven, at a temperature of about 870° C. The coupon was held at that temperature for 2 hours. There was no evidence of coating spallation. After being oven-cooled, the coupon was cross-sectioned for analysis, as in Example 3. The cross-section revealed an aluminum-enriched region on the surface of the coupon. The enriched region had a depth of about 100 microns, prior to removal of any friable residue. As in Example 3, the enriched region included an outer, “high-aluminum” region, and an inner region of aluminum-superalloy interdiffusion. Sample F was stored after use, and its stability was monitored. It remained stable after at least 5 months, i.e., the limit of monitoring at that time. It should be readily apparent that the compositions of this invention exhibit highly desirable stability characteristics. They are also very effective for aluminizing a metal substrate. Moreover, the compositions are substantially free of chromate compounds—especially hexavalent chromium. Furthermore, some preferred embodiments are directed to compositions which are also substantially free of phosphoric acid or its derivatives. This can also represent a distinct advantage, as alluded to above. (Other embodiments allow limited amounts of phosphoric acid, e.g., less than about 10% by weight, based on the weight of the entire composition). This invention has been described according to specific embodiments and examples. However, various modifications, adaptations, and alternatives may occur to one skilled in the art, without departing from the spirit and scope of the claimed inventive concept. All of the patents, articles, and texts which are mentioned above are incorporated herein by reference.
|
C
|
C09
|
C09D
|
1
|
00
|
|||
11939969
|
US20100289509A1-20101118
|
METHOD FOR POSITIONING CARBON NANOTUBES BETWEEN ELECTRODES, BIOMOLECULE DETECTOR BASED ON CARBON NANOTUBE-PROBE COMPLEXES AND DETECTION METHOD USING THE SAME
|
ACCEPTED
|
20101104
|
20101118
|
[]
|
G01R2708
|
["G01R2708"]
|
7928740
|
20071114
|
20110419
|
324
|
692000
|
98597.0
|
NGUYEN
|
HOAI AN
|
[{"inventor_name_last": "CHUNG", "inventor_name_first": "Won Seok", "inventor_city": "Hwaseong-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "YOO", "inventor_name_first": "Kyu Tae", "inventor_city": "Seongnam-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "SHIM", "inventor_name_first": "Jeo Young", "inventor_city": "Yongin-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "LEE", "inventor_name_first": "Junghoon", "inventor_city": "Seongnam-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "CHA", "inventor_name_first": "Misun", "inventor_city": "Seoul", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "HAN", "inventor_name_first": "Junglm", "inventor_city": "Yongin-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "JUNG", "inventor_name_first": "Seungwon", "inventor_city": "Seo-gu", "inventor_state": "", "inventor_country": "KR"}]
|
A device and method are disclosed for detecting biomolecules. More specifically, by measuring the change in the electrical properties of a complex between a probe and carbon nanotubes, a non-label detection is achieved, capable of a rapid, sensitive and electrical detection of the presence and concentration of biomolecules in a sample solution.
|
1. A device for electrical detection of biomolecules comprising: a substrate; a pair of electrodes formed on the substrate and having a gap therebetween; an electrode capable of applying a voltage between either one of the pair of electrodes and the substrate; a detection solution comprising carbon nanotube-probe complexes, the probe being capable of interacting with target biomolecules; a means for positioning the carbon nanotube in the detection solution on a gap between the electrodes; and a means for measuring a change in electrical characteristics. 2. The device of claim 1, wherein the carbon nanotube is a metallic carbon nanotube. 3. The device of claim 2, wherein the carbon nanotube is a single-walled carbon nanotube. 4. The device of claim 1, wherein the target biomolecule is ribonucleic acid or deoxyribonucleic acid. 5. The device of claim 4, wherein the probe is a complementary ribonucleic acid or deoxyribonucleic acid to the target ribonucleic acid or deoxyribonucleic acid. 6. The device of claim 5, wherein the target biomolecule is a deoxyribonucleic acid, and the probe is a complementary single-stranded deoxyribonucleic acid to the target deoxyribonucleic acid. 7. The device of claim 1, wherein the positioning means is a DC power source device capable of applying a DC electric field between the electrodes and an AC power source device capable of applying an AC electric field between the electrodes. 8. The device of claim 7, wherein the DC electric field and the AC electric field are concurrently applied in the form of a composite electric field. 9. The device of claim 8, wherein the DC electric field is a continuously applied DC electric field or a non-continuously applied pseudo DC electric field. 10. The device of claim 1, wherein the measuring means of change in electrical characteristics is an ammeter to measure an electric current between the electrodes. 11. A method for fabricating a device for electrical detection of biomolecules comprising: mixing a carbon nanotube with a probe which is a material capable of interacting with target biomolecules in a solution, thereby forming a detection solution that comprises a carbon nanotube-probe complex and/or carbon nanotubes; contacting the formed detection solution with a sample solution to form a mixture; the sample solution comprising biomolecules to be tested; and positioning the mixture of the detection solution and the sample solution in a gap between electrodes on a substrate; arranging the carbon nanotube-probe complex or the carbon nanotubes in the mixture in the gap between the electrodes, the arranging being accomplished by the application of a composite electric field; the composite electric field comprising an alternate current electric field and a direct current electric field that is in a continuous or non-continuous form. 12. A method for electrically detecting biomolecules, comprising: mixing a carbon nanotube with a probe; the probe being a material that interacts with target biomolecules in a solution; the interaction resulting in the formation of a detection solution that comprises a carbon nanotube-probe complex; contacting the formed detection solution with a sample solution to form a mixture; the sample solution comprising biomolecules to be tested; positioning the mixture of the detection solution and the sample solution in a gap between electrodes on a substrate, thereby arranging the carbon nanotube-probe complex or the carbon nanotubes in the gap between the electrodes; generating an electric field effect between the electrodes; and measuring a first electric field effect. 13. The method of claim 12, further comprising: disposing the detection solution between the electrodes; measuring a second electric field effect; and comparing the first electric field effect with the second electric field effect. 14. The method of claim 12, wherein the carbon nanotube is a metallic nanotube. 15. The method of claim 14, wherein the carbon nanotube is a single-walled carbon nanotube. 16. The method of claim 12, wherein the target biomolecule is a ribonucleic acid or deoxyribonucleic acid. 17. The method of claim 16, wherein the probe is a complementary ribonucleic acid or deoxyribonucleic acid to the target ribonucleic acid or deoxyribonucleic acid. 18. The method of claim 12, wherein the positioning occurs in the presence of a composite electric field; the composite electric field comprising a direct current electric field and an alternating current electric field. 19. The method of claim 18, wherein the direct current electric field is a non-continuously applied pseudo direct current electric field. 20. The method of claim 18, wherein the alternating current electric field of the composite electric field has an intensity ranging from 0.01 to 1000 Vpeak, and a frequency ranging from a 1 MHz to a 10 GHz. 21. The method of claim 18, wherein the composite electric field has an intensity ratio of direct current electric field to the alternating current electric field of up to about 1. 22. The method of claim 19, wherein the pseudo DC electric field has an intensity ratio of up to about 1 relative to the AC electric field and a pulse frequency of the pseudo DC electric field ranging from about 1 KHz to about 10 MHz. 23. The method of claim 12, wherein the measurement of the electric field effect is carried out by using an ammeter to measure an electric current between the electrodes. 24. A method of positioning a carbon nanotube or a carbon nanotube-probe complex in a gap between electrodes, comprising: disposing a solution comprising the carbon nanotube or the carbon nanotube-probe complex in the gap between the electrodes on a substrate; and arranging the carbon nanotube-probe complex or the carbon nanotube in a gap between the electrodes by applying a composite electric field; the composite electric field comprising an alternate current electric field and a direct current electric field. 25. The method of claim 24, wherein the direct current electric field is non-continuously applied.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to a method and device for electrically detecting biomolecules. 2. Description of the Prior Art Carbon nanotubes (CNTs) have a tremendous potential for a wide variety of applications due to their unique mechanical, electrical, and chemical characteristics. The CNTs have excellent characteristics such as extremely high electrical conductivity, high length-to-diameter ratio, and excellent structural strength. Thus, it is expected that CNTs can be used to produce new products that have unique properties compared with existing ones. Single-walled carbon nanotubes (SWCNTs) have attracted attention as new nano-biosensor materials because of their high aspect ratios, excellent chemical, mechanical, and electrical characteristics. SWCNTs exhibit a pronounced change in their electrical characteristics even when reacted to a trace amount of biomolecules. Thus, SWCNT biosensors have been developed that can detect the change in the characteristics of the SWCNTs before and after the reaction to the biomolecules. In the case of most of the presently available biosensors using the SWCNTs, attempts have been made to detect biomolecules with field effect transistors (FETs) or Schottky barrier transistors. These methods generally have difficulties in immobilizing the probe on the surface of the SWCNTs, and are subjected to bonding between the SWCNTs and the biomolecules since the reaction occurs on the surface of a substrate. This bonding is inefficient, since the biomolecule has to be bonded to the SWCNT. Further, there still exists a possibility of alteration in the characteristics of the SWCNT or the target biomolecules due to immobilization of the SWCNT on the surface of the biosensor, or immobilization of the target biomolecules on the surface of the SWCNT. In cases where a non-electrical method is used to detect the biomolecules, fluorescent or other chemical labels are usually attached to the targets to be detected, and then signals generated from the labels are measured. In this case, a pre-treatment process such as labeling target samples is most often utilized and these processes are usually time-consuming, so that it is difficult to analyze various samples in a short time. Further, it is difficult to verify that the labels are attached only to the target biomolecules in the process of the labeling. Thus, it is desirable to have a method and device capable of rapidly and accurately detecting the target biomolecules without any sample pre-treatment process such as the labeling or bonding.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Disclosed herein is a device for electrical detection of biomolecules comprising a substrate; a pair of electrodes formed on the substrate and having a gap therebetween; an electrode capable of applying a voltage between either one of the pair of electrodes and the substrate; a detection solution comprising carbon nanotube-probe complexes, the probe being capable of interacting with target biomolecules; a means for positioning the carbon nanotube in the detection solution on a gap between the electrodes; and a means for measuring a change in electrical characteristics. Disclosed herein too is a method for fabricating a device for electrical detection of biomolecules comprising mixing a carbon nanotube with a probe which is a material capable of interacting with target biomolecules in a solution, thereby forming a detection solution that comprises a carbon nanotube-probe complex; contacting the formed detection solution with a sample solution to form a mixture; the sample solution comprising biomolecules to be tested; and positioning the mixture of the detection solution and the sample solution in a gap between electrodes on a substrate; arranging the carbon nanotube-probe complex or the carbon nanotubes in the mixture in the gap between the electrodes, the arranging being accomplished by the application of a composite electric field; the composite electric field comprising an alternate current electric field and a direct current electric field that is in a continuous or non-continuous form. Disclosed herein too is a method for electrically detecting biomolecules, comprising mixing a carbon nanotube with a probe; the probe being a material that interacts with target biomolecules in a solution; the interaction resulting in the formation of a detection solution that comprises a carbon nanotube-probe complex; contacting the formed detection solution with a sample solution to form a mixture; the sample solution comprising biomolecules to be tested; positioning the mixture of the detection solution and the sample solution in a gap between electrodes on a substrate, thereby arranging the carbon nanotube-probe complex or the carbon nanotubes in the gap between the electrodes; and generating an electric field effect between the electrodes; and, measuring a first electric field effect. Disclosed herein too is a method of positioning a carbon nanotube or a carbon nanotube-probe complex in a gap between electrodes, comprising disposing a solution comprising the carbon nanotube or the carbon nanotube-probe complex in the gap between the electrodes on a substrate; and arranging the carbon nanotube-probe complex or the carbon nanotube in a gap between the electrodes by applying a composite electric field; the composite electric field comprising an alternate current electric field and a direct current electric field that is in a continuous or non-continuous form.
|
CROSS-REFERENCES TO RELATED APPLICATIONS The present invention claims priorities of Korean patent application No. 10-2007-0047239 filed on May 15, 2007, and Korean patent application No. 10-2007-0098352 filed on Sep. 28, 2007, which are hereby incorporated by reference in their entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and device for electrically detecting biomolecules. 2. Description of the Prior Art Carbon nanotubes (CNTs) have a tremendous potential for a wide variety of applications due to their unique mechanical, electrical, and chemical characteristics. The CNTs have excellent characteristics such as extremely high electrical conductivity, high length-to-diameter ratio, and excellent structural strength. Thus, it is expected that CNTs can be used to produce new products that have unique properties compared with existing ones. Single-walled carbon nanotubes (SWCNTs) have attracted attention as new nano-biosensor materials because of their high aspect ratios, excellent chemical, mechanical, and electrical characteristics. SWCNTs exhibit a pronounced change in their electrical characteristics even when reacted to a trace amount of biomolecules. Thus, SWCNT biosensors have been developed that can detect the change in the characteristics of the SWCNTs before and after the reaction to the biomolecules. In the case of most of the presently available biosensors using the SWCNTs, attempts have been made to detect biomolecules with field effect transistors (FETs) or Schottky barrier transistors. These methods generally have difficulties in immobilizing the probe on the surface of the SWCNTs, and are subjected to bonding between the SWCNTs and the biomolecules since the reaction occurs on the surface of a substrate. This bonding is inefficient, since the biomolecule has to be bonded to the SWCNT. Further, there still exists a possibility of alteration in the characteristics of the SWCNT or the target biomolecules due to immobilization of the SWCNT on the surface of the biosensor, or immobilization of the target biomolecules on the surface of the SWCNT. In cases where a non-electrical method is used to detect the biomolecules, fluorescent or other chemical labels are usually attached to the targets to be detected, and then signals generated from the labels are measured. In this case, a pre-treatment process such as labeling target samples is most often utilized and these processes are usually time-consuming, so that it is difficult to analyze various samples in a short time. Further, it is difficult to verify that the labels are attached only to the target biomolecules in the process of the labeling. Thus, it is desirable to have a method and device capable of rapidly and accurately detecting the target biomolecules without any sample pre-treatment process such as the labeling or bonding. SUMMARY OF THE INVENTION Disclosed herein is a device for electrical detection of biomolecules comprising a substrate; a pair of electrodes formed on the substrate and having a gap therebetween; an electrode capable of applying a voltage between either one of the pair of electrodes and the substrate; a detection solution comprising carbon nanotube-probe complexes, the probe being capable of interacting with target biomolecules; a means for positioning the carbon nanotube in the detection solution on a gap between the electrodes; and a means for measuring a change in electrical characteristics. Disclosed herein too is a method for fabricating a device for electrical detection of biomolecules comprising mixing a carbon nanotube with a probe which is a material capable of interacting with target biomolecules in a solution, thereby forming a detection solution that comprises a carbon nanotube-probe complex; contacting the formed detection solution with a sample solution to form a mixture; the sample solution comprising biomolecules to be tested; and positioning the mixture of the detection solution and the sample solution in a gap between electrodes on a substrate; arranging the carbon nanotube-probe complex or the carbon nanotubes in the mixture in the gap between the electrodes, the arranging being accomplished by the application of a composite electric field; the composite electric field comprising an alternate current electric field and a direct current electric field that is in a continuous or non-continuous form. Disclosed herein too is a method for electrically detecting biomolecules, comprising mixing a carbon nanotube with a probe; the probe being a material that interacts with target biomolecules in a solution; the interaction resulting in the formation of a detection solution that comprises a carbon nanotube-probe complex; contacting the formed detection solution with a sample solution to form a mixture; the sample solution comprising biomolecules to be tested; positioning the mixture of the detection solution and the sample solution in a gap between electrodes on a substrate, thereby arranging the carbon nanotube-probe complex or the carbon nanotubes in the gap between the electrodes; and generating an electric field effect between the electrodes; and, measuring a first electric field effect. Disclosed herein too is a method of positioning a carbon nanotube or a carbon nanotube-probe complex in a gap between electrodes, comprising disposing a solution comprising the carbon nanotube or the carbon nanotube-probe complex in the gap between the electrodes on a substrate; and arranging the carbon nanotube-probe complex or the carbon nanotube in a gap between the electrodes by applying a composite electric field; the composite electric field comprising an alternate current electric field and a direct current electric field that is in a continuous or non-continuous form. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. 1 is a picture showing the principle of the detection method of the present invention in which the target biomolecule is DNA, and the probe is a complementary single-stranded DNA(ssDNA) to the target DNA, wherein an SWCNT-ssDNA complex is formed from a single-walled carbon nanotube (SWCNT) and ssDNA and this complex reacts to target DNA. FIG. 2 is a view showing an electrode manufacturing process using nanoimprint lithography (NIL) and resultant electrode with a nano-sized gap; FIG. 3 is a schematic view of a device for positioning SWCNT on the electrodes with a nano-sized gap using a composite electric field guided assembly; FIG. 4 is a picture showing SWCNT-ssDNA complex positioned on the electrodes with a nano-sized gap; FIG. 5 is a conceptual view showing the procedure for positioning SWCNT-DNA complexes reacted to target DNA in a solution and un-reacted complexes on the electrodes. FIG. 6 is a conceptual view of a device for measuring electrical characteristics of SWCNT-ssDNA complex or SWCNT on the electrodes; FIG. 7 is a graph showing measured electrical characteristics of the reacted SWCNT-ssDNA complexes and the un-reacted complexes. FIG. 7A shows that the reacted complex (i.e., SWCNT) is metallic since ISD (i.e., the current between the source and the drain) has constant value regardless of the gate voltage. FIG. 7B shows that the SWCNT-DNA complex shows semi-conducting characteristics only when the complex is wet, thus it is important to measure the electrical characteristics of the complex in the solution. FIG. 7C shows that the reacted complex to target DNA is SWCNT and exhibits metallic behavior, whereas the unreacted complex exhibits semi-conducting behavior; and FIG. 8A is a circuit diagram illustrating an example of composite electric field-guided assembly device, and FIG. 8B shows the effect of the different electric fields (composite, AC only and DC only) upon the arrangement and the assembly of the CNTs. FIG. 9A is a picture showing damaged electrodes in the case of practicing a composite electric field-guided assembly in a buffer solution, where salts are dissolved, using an ordinary continuous DC electric field. FIG. 9B is a picture showing SWCNT-ssDNA complexes assembled on the gap between the electrodes in a buffer solution, where salts are dissolved, using a pulsed pseudo DC electric field according to the composite electric field-guided assembly method. FIG. 9C is a graph showing the result of measuring the electrical characteristics of the SWCNT-ssDNA complexes from the device used in FIG. 9B. DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS Disclosed herein is a device and a method capable of measuring the existence and concentration of the target biomolecules in a simple, rapid, and accurate manner without immobilizing the biomolecules through covalent bonds or labeling the biomolecules with optical or chemical labels. The device and method for biomolecule detection is based on interactions between free carbon nanotubes (CNTs) or a CNT-probe complex and the target biomolecules in a solution without growing or immobilizing the CNTs or the CNT-probe complex on a specific substrate prior to CNT-biomolecule interaction. The device and method can detect a very small quantity of target biomolecules with extremely high sensitivity. More specifically, the method permits the detecting of biomolecules with a high reaction efficiency and sensitivity through reaction between the CNT-probe complexes and the biomolecules and positioning the products of reaction (CNTs or CNT-probe complexes) at desired positions to measure the electrical characteristics of the products of reactions. Herein, “target biomolecules” refer to all biomolecules that interact with “probes,” which will be described below, and are capable of disassembling the complex of the probe and CNT. Thus, all the biomolecules meeting this condition correspond to the target biomolecules, and the scope of these biomolecules are not limited to proteins, nucleic acids, lipids, carbohydrates, or specific complex molecules thereof. Herein, “probes” refer to all molecules capable of interacting with the CNTs to form complexes. The probe is capable of changing the electrical characteristics of the CNTs when it is assembled with the CNTs to form a complex. Such complexes need not be based on a chemical bond such as a covalent or an ionic bond, and it is sufficient if they have strength enough to maintain the complexes under the measurement conditions for the detecting device. Preferably, when the probes are bonded with the metallic (or conductive) CNTs, the CNT-probe complexes exhibit characteristics of a semiconductor. Furthermore, it is desirable for the probes to be capable of being wholly or partly dissociated from the complexes when an interaction between the probe and the target biomolecules occurs. The probes may include proteins, nucleic acids, lipids, or saccharides that bind with the target protein molecules, or nucleic acid that have complementary sequences to target nucleic acid molecules. Further, the probes may include proteins such as leptin that form strong complexes with specific carbohydrate molecules, or proteins such as hormone receptor proteins that are combined with hormones. However, the probe can make use of any molecule having these characteristics, and thus is not limited only to the biomolecule. Herein, the “change in electrical characteristics” refers to any change in the electrical characteristics of a CNT-probe complex that arises out of the interaction between the probe and the target biomolecules. For example, changes in electrical characteristics include a change in electrical resistance, or conversion of electrical property between a conductor and a semiconductor. In one embodiment, an electric field effect is generated in a device that comprises a pair of electrodes functioning as the source and the drain on a substrate and a gate capable of controlling electric current between the source and the drain by applying voltage. A gap between the electrodes ranges from tens of micrometers (μm) to tens of nanometers (nm) and the electric field effect is measured with a proper measuring means. One example of a typical electric field effect device is a field effect transistor (FET). However, in the electric field effect device of the present disclosure, the CNTs or the CNT-probe complexes act as a channel, through which electric current between the source and the drain flows. For this reason, the electric field effect device is characterized in that it does not have a doped silicon layer serving as the channel for electric current, which is different from ordinary FETs. Thus, the field effect device can be provided by modifying an ordinary FET, or by producing a new one. The electric field effect can be measured, for instance, by measuring the electric current or voltage between the source and the drain. In one embodiment, the CNTs can be single-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs) and are preferably SWCNTs. The CNTs used for the detection are preferably metallic (or conductive) nanotubes. An embodiment of detecting the presence of deoxyribonucleic acid (DNA) in a solution sample using the biomolecule detecting device will now be described in detail. The SWCNT and a single-stranded DNA (ssDNA) form a complex due to the characteristics of their molecular structures. The DNA winds itself around the CNT. However, the overall structure of the complex may be of any other shape. For example, the DNA may be attached to the CNT in parallel position. When the complex contacts with a specific DNA molecule, i.e., the target DNA molecule, complementary to the ssDNA (disposed on the probe), the probe ssDNA is disassembled from the complex and a double-stranded DNA (dsDNA) is formed due to hybridization between the target DNA and the probe DNA (i.e., the DNA disposed on the CNT) (see FIG. 1). However, when the complex contacts a non-specific DNA that is not complementary to the probe DNA, the complex keeps its form without being dissembled. Because the hybridization between DNA and RNA or between RNA and RNA is well-known phenomena, this principle can be generally applied to those cases in which the target biomolecules and the probes are not only DNA but also other nucleic acids. In an embodiment in which the target biomolecule is DNA and the probe is the ssDNA complementary to the target DNA, it has been discovered that the complex comprising metallic SWCNT and ssDNA has semiconducting characteristics. Thus, the electrical characteristic of the metallic SWCNT differs from that of the SWCNT-ssDNA complex, and this fact makes it possible to detect target DNA, when the target DNA are complementary to the probe DNA in an easy and accurate manner using a device based on measuring an electric field effect, as described below. 1. SWCNTs are mixed with the ssDNAs complementary to the target DNA in the appropriate solution and the SWCNTs and ssDNAs form SWCNT-ssDNA complexes. 2. The sample solution to be tested for the presence of the target DNA is mixed to the solution containing the SWCNT-ssDNA complexes. If the target DNA exists in the sample solution, reaction between target DNAs and ssDNAs in the complexes disassembles the SWCNT-ssDNA complexes into the SWCNTs and the ssDNAs. 3. Resultant products of reaction (the SWCNT-ssDNA complexes or the SWCNTs) processed in step 2, are positioned in the gap between the electrodes of the electric field effect device to measure the electrical characteristics of products of reaction. 4. The electric field effect is measured with a gate voltage sweep applied to the electric field effect device. Then, it can be determined whether the target DNA exists in the sample solution or not from the measured data (metallic or semi-conducting characteristics of products of reaction in step 2). Both the processes of forming the complex and the contacting of the complex with the complementary DNA take place in a solution. In order to measure the electric characteristics of a resultant product of the contacting, it is important to manufacture the proper electrodes and to arrange the products of the contacting, i.e. the SWCNT-ssDNA complexes or SWCNTs, in the gap between the electrodes after the reaction (see FIG. 5). FIG. 2A represents exemplary schematic views of the process of manufacturing the electrode, while FIG. 2B shows micrographs that depict the result at each step in the manufacturing of electrodes having a suitable gap size. FIG. 2A shows the manufacturing of an electrode using nanoimprint lithography (NIL). First, a substrate coated with a polymeric protection layer is pressed in a mold. In the embodiment depicted in the FIG. 2A, the polymeric protection layer comprises a first layer and a second layer. The substrate generally comprises silicon, while the first layer comprises polymer, e.g., PMMA(polymethyl methacrylate) or PMGI(polymethyl glutarimide), and the second layer comprises resin for imprint. The first layer is deposited on the substrate to protect the substrate. The second layer is deposited on the first layer to form a pattern on the first layer. Further, the second layer may protect the first layer as a mask later during the etching process. The first layer and the second layer may be deposited by spin coating. Then, the protection layer is cross-linked using heat or light. The mold is removed and the first and second protection layers on the substrate are removed by oxygen plasma etching. Following the oxygen plasma etching, a metal electrode is disposed upon the substrate. When metal electrodes (e.g., Au in FIG. 2A) are directly deposited on an undoped silicone substrate as in the embodiment shown in FIGS. 2A and 2B, there is no a channel for electric current between the electrodes functioning as a source and a drain. In one embodiment, it may not be desirable to remove the insulating layer laminated on the substrate. The metal electrodes can be directly disposed on a doped polymeric layer. Following the deposition of the electrodes, the CNTS or the CNT-probe complexes are arranged on a gap between the electrodes to function as a channel. However, it is not essential to use the undoped silicone substrate, but various materials including doped silicone and other synthetic resins can be used for the substrate. It is desirable to arrange the CNT-probe complexes or the CNTS on a gap between the electrodes. This is generally accomplished using dielectrophoresis (DEP) with only an alternating current (AC). In another embodiment, composite electric field-guided assembly (CEGA) is used to arrange the CNT-probe complexes or the CNTS on the gap between the electrodes. This is accomplished as follows: a solution containing the dispersed CNTs is placed on a gap between pre-patterned electrodes and then a composite electric field with a specific condition is applied to the solution through the electrodes for the purpose of arranging the CNTs as intended (see FIG. 3). Applying the composite electric field means that both of AC and DC electric fields are applied to the electrodes simultaneously. The DC electric field may be a typical electric field or a pulsed electric field. Hereinafter the pulsed electric field will be referred to as a “pseudo-DC electric field.” By properly selecting the intensity and the frequency of the AC and DC electric fields of the composite electric field, orienting of the CNTS or CNT-probes between the electrodes can be achieved. The CEGA has advantages when compared to existing methods in the following aspects: 1) Since the CNT or the CNT-probes are assembled by forcibly orienting them (while disposed in a solution) to an electrode, it is advantageous to detect a CNTs or CNT-probes when present in a low density, when used in a measurement. Consequently, it is possible to automatically assemble one nano element in a desired position. 2) The CNTs can be assembled selectively. When conductive CNTs are mixed with semi-conducting CNTs, the conducting or semi-conducting CNTs can be selectively located and assembled only by adjusting the frequency and the voltage. 3) Electro-osmotic force by AC current acts to straighten the CNTs as well as generate a downstream flow so that the CNTs can be more easily attached to the electrodes. When an electric field is applied on both of the electrodes, the solution positioned in the gap between the electrodes is forced and forms a current therewithin towards the substrate (i.e., perpendicular to the substrate). The downstream flow means such flow of the solution in the gap between the electrodes when the electric field is applied to the electrodes. FIG. 8A is a circuit diagram illustrating an example of an apparatus for applying such a composite electric field. According to the circuit shown in FIG. 8A, DC and AC power sources are connected in series and a capacitor and a resistor having a high resistance value are connected in parallel. FIG. 8B is a conceptual view illustrating a process of positioning CNTs on a gap between pair of electrodes using the device as shown in FIG. 8A. In FIG. 8B, (a) indicates a situation prior to the application of a composite electric field, the rods in the figure representing CNTs, while the dots represent other impurities (b) indicates a situation where dielectrophoresis takes place only by an AC electric field, (c) indicates a situation where dielectrophoresis takes place only by a DC electric field, and (d) the CNTs are assembled by a composite electric field. The DC electric field may be implemented in the form of a pseudo-DC electric field as mentioned above. This is effective in a case where biomolecules to be detected are suspended or dissolved into a buffer solution, where inorganic and organic salts are dissolved, for the purpose of stability and functionality of the biomolecules. In the case of applying an ordinary continuous DC electric field in order to arrange the CNTs included in a buffer solution, where salts are dissolved, electrodes can be damaged due to electrolysis. In this case, using a pulsed, pseudo DC electric field makes it possible to arrange the CNTs between the pair of electrodes without damaging the electrodes. After the CNTs or CNT-probe complexes are positioned between the pair of electrodes of a field effect device by the CEGA method or other known methods, field effect is measured (see FIG. 5). This is different from a typical FET in that the CNTs or the CNT-probe complexes act as a channel of current, which flows between a source and a drain (i.e., a pair of electrode). The method of measuring the field effect can be implemented with any method that measures a current flowing between the source and the drain or other known methods that measure the electric characteristics of the FET. A concept of measuring the electric current is illustrated in FIG. 6. EXAMPLES Hereinafter the present invention will be described in more detail with reference to Examples. It should be construed that Examples are give for the illustrative purposes only but do not limit the scope of protection of the present invention. Example 1 Production and Hybridization of SWCNT-ssDNA Complexes In order to make SWCNT-ssDNA complexes, metallic SWCNTs (available from Carbon Nanotechnologies Inc. in Texas, USA) were sonicated for 90 mins in a DNA solution (15 μm 18-mer Poly (dG) or Poly (dC)), which was dissolved into deionized water, followed by a centrifugation to remove impurities. While the deionized water was used in Example 1, the DNA solution can be implemented with other suitable buffer solutions such as 0.1 M NaCl solution or PBS solution. The average length of the SWCNTs used was about 1 μm. In order to hybridize a portion of the produced complexes with a target DNA (for example, the target DNA is complementary 18-mer poly (dC) DNA to 18-mer poly (dG) in the case that the probe is 18-mer poly (dG)), the solution containing the complex was added with the same amount of a 15 μm solution of the DNA to be detected. Then, the resultant solution was allowed to react overnight (about 24 hours). The complexes and the hybridized complexes were used in the field effect measurement. Example 2 Arranging SWCNT-ssDNA Complexes or SWCNTs in Electrode Gap By using the CEGA method, the SWCNT-ssDNA complexes formed in Example 1 or the hybridized complexes (i.e., SWCNT with ssDNA dissociated) were located between the electrodes of a field effect device. A circuit as shown in FIG. 8A was used to generate a composite electric field. In the case of arranging the SWCNT-ssDNA complexes or the SWCNTs using the CEGA method, it is difficult to present general arrangement conditions, which can be widely used, since the arrangement of the SWCNT-ssDNA complexes or the SWCNTs is variable according to the gap size of the electrodes, the length of the SWCNTs and reaction conditions. In Example 2, a device of generating field effect, which has an electrode gap of 300 nm, was manufactured using the aforementioned nanoimprint lithography. In the composite electric field used to position the SWCNT-ssDNA complexes or the SWCNTs produced in Example 1, the frequency of an AC electric field was 5 MHz, the intensity of the AC electric field was 2.96 Vpeak, and an intensity ratio of DC to AC electric field was 0.345. While an ordinary continuous DC electric field was used instead of the CEGA, it is preferable to use a pulsed pseudo DC electric field where the SWCNT and ssDNAs are dissolved into a buffer solution unlike the water used in Example 1 above. FIG. 4 is a picture illustrating SWCNT-ssDNA complexes assembled between electrodes having an electrode gap of 300 nm, by using the aforementioned CEGA method. Example 3 Measuring Field Effect After SWCNTs or SWCNT-ssDNA complexes were positioned between the pair of electrodes of a device that generates a field effect, a current between a source and a drain was measured. Biomolecules to be measured and probes were implemented with (dG)18 and (dC)18 (see FIGS. 7A and 7B) or with 17 mer random base sequences (ccg acc gac gtc ggt cg) and their complementary strands (see FIG. 7C), respectively. In order to measure field effect, variations in current ISD between the source and the drain were measured with a semiconductor analyzer (HP4155A) by sweeping a gate voltage from −15 V to +15 V. The result is reported in FIGS. 7A to 7C. FIG. 7A shows that the assembled SWCNTs were metallic since ISD (i.e., a current flowing between the source and the drain) did not change according to a gate voltage irrespective of the existence of moisture when electric characteristics of the SWCNTs prior to reaction were measured. FIG. 7B shows the importance of maintaining a solution phase in a space between the pair of electrodes while the measurement was being carried out since the SWCNT-ssDNA complexes showed a semi-conducting property only in the solution phase. FIG. 7C is a graph illustrating that the CNTs were metallic when field effect was measured since probe ssDNAs were dissociated to reduce into the SWCNTs and that the complexes, which were not hybridized, were still SWCNT-ssDNA complexes. As shown in FIG. 7A, when DNAs were combined with originally metallic SWCNTs, semi-conducting characteristics were obtained. Thus, when electric characteristics of reactants were measured after the complexes made of the metallic SWCNTs were reacted to the DNAs to be detected, metallic property indicates that the DNAs to be detected existed in a specification but semi-conducting property indicates that the DNAs to be detected did not exist in the sample. Example 4 Assembling SWCNT-ssDNA Complexes in a Buffer Solution by using a Pulsed Pseudo DC Electric Field According to the CEGA Method FIG. 9A is a picture showing damaged electrodes in the case of assembling SWCNT-ssDNA complexes in a buffer solution, where salts are dissolved, using an ordinary continuous DC electric field according to the CEGA method. Electrodes are damaged as shown in FIG. 9A since electrodes are oxidized due to the electrolysis when the continuous DC electric field is applied to the buffer solution wherein salts are dissolved. FIG. 9B is a picture showing SWCNT-ssDNA complexes assembled well on the electrodes with a nano-sized gap in the case of assembling SWCNT-ssDNA complexes in a buffer solution, where salts are dissolved, using a pulsed pseudo DC electric field according to the CEGA method. Thus, it is preferable to position the SWCNT-ssDNA complexes or the SWCNTs on the gap between the pair of electrodes by using the pulsed pseudo DC electric field in a case where the SWCNT and ssDNAs are dissolved into the buffer solution that contains dissolved salts. In the composite electric field used to assemble SWCNT-ssDNA complexes, the frequency of the AC electric field (of sine wave) was 5 MHz, the intensity of the AC electric field was 2.96 Vpeak, the frequency of the pseudo DC electric field of square wave was 500 kHz, and the intensity ratio of DC to AC electric field was 0.345. It took 1 minute to assemble SWCNT-ssDNA complexes. FIG. 9C is a graph showing the result of measuring the electrical characteristics of the SWCNT-ssDNA complexes from the device used in FIG. 9B. As shown in FIG. 9C, the SWCNT-ssDNA complexes have semi-conducting characteristics and, it can be seen that the SWCNT-ssDNA complexes are assembled well in the gap between the pair of electrodes through the electrical characteristics. While the aforementioned example has been described with respect to SWCNT and ssDNA, various complexes of nano elements and biomolecules can be adopted in the present invention. The device and the method of detecting biomolecules as set forth above are a novel and new approach that can enhance reaction efficiency by fixing nano elements after reaction of nano elements in a solution phase as well as lower detection limit by using the CEGA method unlike conventional nano-bio sensors. Accordingly, it is possible to achieve an original technology that can cause innovation in the existing biosensor field in order to develop biosensors having enhanced characteristics such as detection density, time and volume. Furthermore, it is applicable to biosensor fields where it is desirable to measure a faint amount of biomolecules with high sensitivity as well as to high-tech detection methods such as a lab-on-a-chip method. While the present invention has been described with reference to the particular illustrative embodiments and the accompanying drawings, it is not to be limited thereto but will be defined by the appended claims. It is to be appreciated that those skilled in the art can substitute, change or modify the embodiments into various forms without departing from the scope and spirit of the present invention.
|
G
|
G01
|
G01R
|
27
|
08
|
|||
11704262
|
US20070200918A1-20070830
|
Method for setting mute flags to improve compatibilities and the high definition multimedia interface system using the same method
|
ACCEPTED
|
20070816
|
20070830
|
[]
|
H04N714
|
["H04N714"]
|
7773107
|
20070209
|
20100810
|
725
|
080000
|
61420.0
|
BROCKMAN
|
ANGEL
|
[{"inventor_name_last": "Kwon", "inventor_name_first": "Kwang Hun", "inventor_city": "Yongin-si", "inventor_state": "", "inventor_country": "KR"}, {"inventor_name_last": "Kim", "inventor_name_first": "Chang Hoon", "inventor_city": "Seongnam-si", "inventor_state": "", "inventor_country": "KR"}]
|
The present invention relates to an HDMI (High Definition Multimedia Interface) system, and more particularly, to a method for setting mute flag in connection with transmission of audio data and auxiliary data transmitted through HDMI system, and an HDMI system using the same method.
|
1. An HDMI system comprising a source device having a sender which sends at least one of video data, audio data and auxiliary data, cables passing the vide data, audio data and auxiliary data from the source device and a sink device having a receiver which receives the data from the source device, said audio data and auxiliary data being contained in GCP (General Control Packet) comprising: a packet header indicating the packet type; and a subpacket comprising at least one of single mute flags of audio mute flag and video mute flag and complex mute flag. 2. The HDMI system according to claim 1, wherein the audio mute flag comprises audio mute setting flag and audio mute clearing flag. 3. The HDMI system according to claim 1, wherein the video mute flag comprises video mute setting flag and video mute clearing flag. 4. The HDMI system according to claim 1, wherein the subpacket consists of 8 bytes, SB0 through SB7 which comprise the single mute flags and complex mute flags. 5. The HDMI system according to claim 1, wherein the subpacket consists of 8 bytes, SB0 through SB7, and the complex mute flag is contained in SB0 and single mute flags are contained in one of SB1 through SB7. 6. The HDMI system according to claim 1, wherein the source device is one of set-top box and DVD player, and the sink device is digital TV. 7. A mute flag controlling method in an HDMI system comprising a source device having a sender which sends at least one of video data, audio data and auxiliary data, cables passing the vide data, audio data and auxiliary data from the source device and a sink device having a receiver which receives the data from the source device, said audio data and auxiliary data being contained in GCP (General Control Packet) comprising the steps of: requesting change of setting value in the source device; setting at least one of the audio mute setting flag and video mute setting flag in the source device; transmitting the set mute flag from the source device to the sink device; muting one of the audio signal or the video signal while playing the other; completing the request of changing setting value; setting mute clearing flag of one of the set mute flag; transmitting the set mute flag from the source device to the sink device; and releasing the mute of the audio signal or the video signal. 8. A mute flag controlling method according to claim 7, wherein the audio mute flag comprises audio mute setting flag and audio mute clearing flag. 9. A mute flag controlling method according to claim 7, wherein the video mute flag comprises video mute setting flag and video mute clearing flag. 10. A mute flag controlling method according to claim 7, wherein the subpacket consists of 8 bytes, SB0 through SB7 which comprise the single mute flags and complex mute flags. 11. A mute flag controlling method according to claim 7, wherein the subpacket consists of 8 bytes, SB0 through SB7, and the complex mute flag is contained in SB0 and single mute flags are contained in one of SB1 through SB7. 12. A mute flag controlling method according to claim 7, wherein the source device is one of set-top box and DVD player, and the sink device is digital TV.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention relates to an HDMI (High Definition Multimedia Interface) system, and more particularly, to a method for setting mute flag in connection with transmission of audio data and auxiliary data transmitted through HDMI system, and an HDMI system using the same method. 2. Description of the Related Art HDMI is a standard for connecting a source device which sends data and a sink device which receives data, wherein the source device may be, for example, set-top box or DVD player and the sink device may be, for example, digital TV. General architecture of HDMI system is suggested in “HDMI specification version 1.2a, FIG. 3-1 HDMI Block diagram”, which is incorporated herewith as FIG. 1 . Referring to FIG. 1 of the present invention, an HDMI system consists of a source device 100 which sends data and a sink device 200 which receives data. Each of source device and sink device may have more than one HDMI inputs and HDMI outputs. All the HDMI inputs at the source device and the sink device conform to the specification for the HDMI sink device, and all the HDMI outputs at the HDMI system accconformords to the specification the for HDMI source device. As shown in FIG. 1 , HDMI cable 300 employed in HDMI system holds four different channels, each of which consists of TDMS (Transition Minimized Differential Signaling) data channels 301 , 302 , 303 and clock channel 304 . These channels are used for transmitting video data, audio data and auxiliary data. Also, HDMI system holds VESA (Video Electronics Standards Association) DDC (Display Data Channel) 400 , which is used for exchanging configuration and status information between the single source device and the single sink device. Alternatively, HDMI system may use CEC (Consumer Electronics Control) line 500 which transmits CEC protocol to provide high level control among various viewing devices in user environment. As described above, audio data, video data and auxiliary data are transmitted from HDMI sender 101 of the source device 100 to HDMI receiver 201 of the sink device 200 through three TMDS (Transition Minimized Differential Signaling) data channels 301 , 302 , 303 and video pixel clock is transmitted through TMDS clock channel 304 . The video pixel clock is used as frequency standard for restoring data on three TMDS data channel 301 , 302 , 303 by receiver 201 of sink device 202 . The difference between traditional DVI (Digital Visual Interface) system and HDMI system is that audio data and auxiliary data as well as video data are transmitted through HDMI cable 300 . Video data is transmitted as a series of 24 bit pixel on the three TMDS data channels and HDMI system employs packet structure for transmitting audio data and auxiliary data. There is a packet type called General Control packet in HDMI specification version 1.2a (see table 3). The General Control packet was introduced in HDMI specification for muting audio and video signal simultaneously to reduce transient impacts between the source device and the sink device. The General Control packet retains Clear_AVMUTE flag and Set_AVMUTE flag for muting or for releasing the muting of audio and video signal simultaneously. It is optional for the source device to send muting signal, but is required for the sink device to receive the signal for muting signal. Further, it is optional for the sink device to effectively process the received muting signal. The reason HDMI system employs these mute flags are to minimize the transient impacts due to the status changes when the source device sends signals to the sink device. For example, it is possible to prevent audio pop noise which may occur in the source device by setting the AVMUTE flags. When Set-AVMUTE flag is set in the source device, the sink device receives invalid video or audio signal. Accordingly, HDMI sink device can optionally perform the muting of video or audio signal as required. Recently, most of home appliances are equipped with HDMI input/output terminals. Also, many high level functions (e.g. memory card operability) are increasingly added to set-top boxes or DVD players which meet the HDMI specification. Accordingly, the interoperability between the various source devices and the sink devices becomes an important issue. More specifically, during transient period when resolution or frequency is being changed between the source device and the sink device, there may occur flickering or noise (hereinafter transient impacts). To prevent the transient impact, a technology to reduce transient impact of devices employing HDMI specification, or a technology to increase interoperability between devices is required. The mute flags retained in the General Control packet of HDMI specification could be a solution to increase the interoperability between the source device and the sink device. Meanwhile, sometimes it is enough to simultaneously set Clear_AVMUTE flag and Set_AVflag to mute or release muting both audio signal and video signal (e.g. when the resolution is being changed), but at other times it is required to mute or release muting one of audio signal and video signal. For example, when playing back MP3 file from memory card which was added as a high level function or when changing frequency of MP3 file, more detailed control to selectively mute or release muting one of audio or video signal is desirable rather than to mute or release muting both of them. The need for more detailed control is increasing according to the high-end trend and diversification of source device and sink device.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, an object of the present invention is to provide a HDMI system and a mute flag control method of the same that enable selective control of audio or video mute flag and reduce the transient impacts of related art in which one could not but mute or release muting of both audio and video signal, and to substantially obviate one or more problems due to limitations and disadvantages of the related art. Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided an HDMI system comprising a source device having a sender which sends at least one of video data, audio data and auxiliary data, cables passing the vide data, audio data and auxiliary data from the source device and a sink device having a receiver which receives the data from the source device, said audio data and auxiliary data being contained in GCP (General Control Packet) comprising: a packet header indicating the packet type; and a subpacket comprising at least one of single mute flags of audio mute flag and video mute flag and complex mute flag. In a preferred embodiment, the audio mute flag comprises audio mute setting flag and audio mute clearing flag. In a preferred embodiment, the video mute flag comprises video mute setting flag and video mute clearing flag. In a preferred embodiment, the subpacket consists of 8 bytes, SB 0 through SB 7 which comprise the single mute flags and complex mute flags. In a preferred embodiment, the subpacket consists of 8 bytes, SB 0 through SB 7 , and the complex mute flag is contained in SB 0 and single mute flags are contained in one of SB 1 through SB 7 . In a preferred embodiment, the source device is one of set-top box and DVD player, and the sink device is digital TV. In another aspect of the present invention, there is provided a mute flag controlling method in an HDMI system comprising a source device having a sender which sends at least one of video data, audio data and auxiliary data, cables passing the vide data, audio data and auxiliary data from the source device and a sink device having a receiver which receives the data from the source device, said audio data and auxiliary data being contained in GCP (General Control Packet) comprising the steps of: requesting change of setting value in the source device; setting at least one of the audio mute setting flag and video mute setting flag in the source device; transmitting the set mute flag from the source device to the sink device; muting one of the audio signal or the video signal while playing the other; completing the request of changing setting value; setting mute clearing flag of one of the set mute flag; transmitting the set mute flag from the source device to the sink device; and releasing the mute of the audio signal or the video signal. In a preferred embodiment, the audio mute flag comprises audio mute setting flag and audio mute clearing flag. In a preferred embodiment, the video mute flag comprises video mute setting flag and video mute clearing flag. In a preferred embodiment, the subpacket consists of 8 bytes, SB 0 through SB 7 which comprise the single mute flags and complex mute flags. In a preferred embodiment, the subpacket consists of 8 bytes, SB 0 through SB 7 , and the complex mute flag is contained in SB 0 and single mute flags are contained in one of SB 1 through SB 7 . In a preferred embodiment, the source device is one of set-top box and DVD player, and the sink device is digital TV. It is to be understood that both the foregoing general description and the following detailed description of the present invention is exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRFSUM description="Brief Summary" end="tail"?
|
The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2005-0014375 (filed on Feb. 14, 2006), which is hereby incorporated by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an HDMI (High Definition Multimedia Interface) system, and more particularly, to a method for setting mute flag in connection with transmission of audio data and auxiliary data transmitted through HDMI system, and an HDMI system using the same method. 2. Description of the Related Art HDMI is a standard for connecting a source device which sends data and a sink device which receives data, wherein the source device may be, for example, set-top box or DVD player and the sink device may be, for example, digital TV. General architecture of HDMI system is suggested in “HDMI specification version 1.2a, FIG. 3-1 HDMI Block diagram”, which is incorporated herewith as FIG. 1. Referring to FIG. 1 of the present invention, an HDMI system consists of a source device 100 which sends data and a sink device 200 which receives data. Each of source device and sink device may have more than one HDMI inputs and HDMI outputs. All the HDMI inputs at the source device and the sink device conform to the specification for the HDMI sink device, and all the HDMI outputs at the HDMI system accconformords to the specification the for HDMI source device. As shown in FIG. 1, HDMI cable 300 employed in HDMI system holds four different channels, each of which consists of TDMS (Transition Minimized Differential Signaling) data channels 301, 302, 303 and clock channel 304. These channels are used for transmitting video data, audio data and auxiliary data. Also, HDMI system holds VESA (Video Electronics Standards Association) DDC (Display Data Channel) 400, which is used for exchanging configuration and status information between the single source device and the single sink device. Alternatively, HDMI system may use CEC (Consumer Electronics Control) line 500 which transmits CEC protocol to provide high level control among various viewing devices in user environment. As described above, audio data, video data and auxiliary data are transmitted from HDMI sender 101 of the source device 100 to HDMI receiver 201 of the sink device 200 through three TMDS (Transition Minimized Differential Signaling) data channels 301, 302, 303 and video pixel clock is transmitted through TMDS clock channel 304. The video pixel clock is used as frequency standard for restoring data on three TMDS data channel 301, 302, 303 by receiver 201 of sink device 202. The difference between traditional DVI (Digital Visual Interface) system and HDMI system is that audio data and auxiliary data as well as video data are transmitted through HDMI cable 300. Video data is transmitted as a series of 24 bit pixel on the three TMDS data channels and HDMI system employs packet structure for transmitting audio data and auxiliary data. There is a packet type called General Control packet in HDMI specification version 1.2a (see table 3). The General Control packet was introduced in HDMI specification for muting audio and video signal simultaneously to reduce transient impacts between the source device and the sink device. The General Control packet retains Clear_AVMUTE flag and Set_AVMUTE flag for muting or for releasing the muting of audio and video signal simultaneously. It is optional for the source device to send muting signal, but is required for the sink device to receive the signal for muting signal. Further, it is optional for the sink device to effectively process the received muting signal. The reason HDMI system employs these mute flags are to minimize the transient impacts due to the status changes when the source device sends signals to the sink device. For example, it is possible to prevent audio pop noise which may occur in the source device by setting the AVMUTE flags. When Set-AVMUTE flag is set in the source device, the sink device receives invalid video or audio signal. Accordingly, HDMI sink device can optionally perform the muting of video or audio signal as required. Recently, most of home appliances are equipped with HDMI input/output terminals. Also, many high level functions (e.g. memory card operability) are increasingly added to set-top boxes or DVD players which meet the HDMI specification. Accordingly, the interoperability between the various source devices and the sink devices becomes an important issue. More specifically, during transient period when resolution or frequency is being changed between the source device and the sink device, there may occur flickering or noise (hereinafter transient impacts). To prevent the transient impact, a technology to reduce transient impact of devices employing HDMI specification, or a technology to increase interoperability between devices is required. The mute flags retained in the General Control packet of HDMI specification could be a solution to increase the interoperability between the source device and the sink device. Meanwhile, sometimes it is enough to simultaneously set Clear_AVMUTE flag and Set_AVflag to mute or release muting both audio signal and video signal (e.g. when the resolution is being changed), but at other times it is required to mute or release muting one of audio signal and video signal. For example, when playing back MP3 file from memory card which was added as a high level function or when changing frequency of MP3 file, more detailed control to selectively mute or release muting one of audio or video signal is desirable rather than to mute or release muting both of them. The need for more detailed control is increasing according to the high-end trend and diversification of source device and sink device. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a HDMI system and a mute flag control method of the same that enable selective control of audio or video mute flag and reduce the transient impacts of related art in which one could not but mute or release muting of both audio and video signal, and to substantially obviate one or more problems due to limitations and disadvantages of the related art. Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided an HDMI system comprising a source device having a sender which sends at least one of video data, audio data and auxiliary data, cables passing the vide data, audio data and auxiliary data from the source device and a sink device having a receiver which receives the data from the source device, said audio data and auxiliary data being contained in GCP (General Control Packet) comprising: a packet header indicating the packet type; and a subpacket comprising at least one of single mute flags of audio mute flag and video mute flag and complex mute flag. In a preferred embodiment, the audio mute flag comprises audio mute setting flag and audio mute clearing flag. In a preferred embodiment, the video mute flag comprises video mute setting flag and video mute clearing flag. In a preferred embodiment, the subpacket consists of 8 bytes, SB0 through SB7 which comprise the single mute flags and complex mute flags. In a preferred embodiment, the subpacket consists of 8 bytes, SB0 through SB7, and the complex mute flag is contained in SB0 and single mute flags are contained in one of SB1 through SB7. In a preferred embodiment, the source device is one of set-top box and DVD player, and the sink device is digital TV. In another aspect of the present invention, there is provided a mute flag controlling method in an HDMI system comprising a source device having a sender which sends at least one of video data, audio data and auxiliary data, cables passing the vide data, audio data and auxiliary data from the source device and a sink device having a receiver which receives the data from the source device, said audio data and auxiliary data being contained in GCP (General Control Packet) comprising the steps of: requesting change of setting value in the source device; setting at least one of the audio mute setting flag and video mute setting flag in the source device; transmitting the set mute flag from the source device to the sink device; muting one of the audio signal or the video signal while playing the other; completing the request of changing setting value; setting mute clearing flag of one of the set mute flag; transmitting the set mute flag from the source device to the sink device; and releasing the mute of the audio signal or the video signal. In a preferred embodiment, the audio mute flag comprises audio mute setting flag and audio mute clearing flag. In a preferred embodiment, the video mute flag comprises video mute setting flag and video mute clearing flag. In a preferred embodiment, the subpacket consists of 8 bytes, SB0 through SB7 which comprise the single mute flags and complex mute flags. In a preferred embodiment, the subpacket consists of 8 bytes, SB0 through SB7, and the complex mute flag is contained in SB0 and single mute flags are contained in one of SB1 through SB7. In a preferred embodiment, the source device is one of set-top box and DVD player, and the sink device is digital TV. It is to be understood that both the foregoing general description and the following detailed description of the present invention is exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: FIG. 1 is a block diagram of HDMI system specified by HDMI specification version 1.2a. FIG. 2 shows flow of AVMUTE flag of General Control packet according to an embodiment of the present invention. FIG. 3 shows flow of AMUTE flag of General Control packet according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer the same or like parts. In HDMI system, links for transmitting and receiving data between source device and sink device consist of Video Data Period, Data Island Period, and Control Period. During the Video Data Period, active pixels of active video line are transmitted. During the Island Period audio data and auxiliary data are transmitted as a series of packets. Control Period is when there is no need to transmit video, audio or auxiliary data. Among these, Data Island Period is related to the feature of the present invention, and during the Island Period packets of audio sample data and auxiliary data are transmitted. The auxiliary data comprise EIA/CEA-861B InfoFrames and other data describing active audio or video stream or source device. The structure of Data Island Packet used in Data Island Period is as follows. All the data in one Data Island are included in 32 pixel packet. A packet consists of one packet header, packet body (which consists of four subpackets) and error correction bit. Each of the subpackets comprises 56 bit data, and is protected by 8 bit BCH ECC parity bits. A packet header comprises 24 data bits and additional 8 bit BCH (32, 24) ECC parity bits. The parity bits are produced from 24 bits of packet header. A packet header comprises 8 bit packet type and 16 bit packet specific data. Table 1 shows structure of packet header cited from Table 5-7 of HDMI specification 1.2a. TABLE 1 Structure of packet header bit# Byte 7 6 5 4 3 2 1 0 HB0 Packet type HB1 Packet specific data HB2 Packet specific data As shown in Table 1, the first byte HB0 indicates packet type, the second byte and the third byte, HB1 and HB2 packet specific data. TABLE 2 Example in which a certain packet type (General Control Packet) is designated (HDMI specification version 1.2 Table 5-16) bit# Byte 7 6 5 4 3 2 1 0 HB0 1 1 HB1 HB2 Table 2 shows packet type of HB0 is “3” in which bit 0 and bit 1 are “1” of the first byte, which indicates the packet type is General Control packet of one embodiment of the present invention. TABLE 3 Packet type (HDMI specification version 1.2a Table 5-8) Packet Type Value Packet Type 0x00 NULL 0x01 Audio Clock Generation (N/CTS) 0x02 Audio Sample (L-PCM and compressed formats) 0x03 General Control 0x04 ACP Packet 0x05 ISRC1 Packet 0x06 ISRC2 Packet 0x07 1 Bit Audio Sample Packet 0x80+ InfoFrame Type EIA/CEA-861B InfoFrame 0x81 Vendor-Specific InfoFrame 0x82 AVI InfoFrame* 0x83 Source Product Descriptor InfoFrame 0x84 Audio InfoFrame 0x85 MPEG Source InfoFrame As shown in Table 3, the difference of HDMI especially from DVI is that various Island packets such as Null, Audio Clock Regeneration (N/CTS), Audio Sample (L-PCM, compress formats) can be transmitted and received during Data Island Period. One packet type lout of the various Island packets is General Control packet. The subpacket structure of General Control packet is shown in Table 4. TABLE 4 General Control Subpacket (HDMI specification version 1.2a Table 5-17) bit# Byte 7 6 5 4 3 2 1 0 SB0 0 0 0 Clear_AVMUTE 0 0 0 Set_AVMUTE SB1 0 0 0 0 0 0 0 0 SB2 0 0 0 0 0 0 0 0 SB3 0 0 0 0 0 0 0 0 SB4 0 0 0 0 0 0 0 0 SB5 0 0 0 0 0 0 0 0 SB6 0 0 0 0 0 0 0 0 SB7 0 0 0 0 0 0 0 0 Subpacket of HDMI General Control consists of 7 bytes, SB0˜SB6R as shown in Table 4, in which SB0 is presently used to include Set_AVMUTE flag in bit 0 and Clear_AVMUTE in bit 4. In other words, mute flags of General Control in prior art is complex mute flags for muting or releasing muting of both audio and video signal, and cannot but mute or release muting of both audio and video signal at the same time. TABLE 5 Subpacket of General Control according to an embodiment of the present invention bit# Byte 7 6 5 4 3 2 1 0 SB0 0 Clear_AMUTE Clear_VMUTE Clear_AVMUTE 0 Set_AMUTE Set_VMUTE Set_AVMUTE SB1 0 0 0 0 0 0 0 0 SB2 0 0 0 0 0 0 0 0 SB3 0 0 0 0 0 0 0 0 SB4 0 0 0 0 0 0 0 0 SB5 0 0 0 0 0 0 0 0 SB6 0 0 0 0 0 0 0 0 SB7 0 0 0 0 0 0 0 0 As shown in Table 5, mute flags according to an embodiment of the present invention comprise single mute flags, Set_AMUTE, Clear_AMUTE, Set_VMUTE and Clear_VMUTE for controlling audio or video signal as well as complex mute flgas, Set_AVMUTE and Clear_AVMUTE for controlling audio and video signal at the same time. In this configuration, assuming HDMI source device and HDMI sink device are connected and performing the playback of MP3, when bit 3, #2 of the first byte SB0 is set to 1 and sampling frequency of MP3 file is changed, transient impacts can be reduced by simply muting only audio signal. As such, it is not needed to mute both audio and video signals. More specifically, when sampling frequency of audio signal is being changed, the sink device may produce negative impacts such as pop noises due to the change of internal clock. In this case, the source device sets Set_AMUTE flag to 1 not Set_AVMUTE flag, and the sink device mutes the audio signal while the source is performing the internal process for changing sample frequency. After the internal process is completes, the source device sets Clear_AMUTE to 1, and the sink device receives data in which Clear_AMUTE is set to 1. And then the sink device releases the muting of audio signal. In terms of mute control as above, that is, by selectively muting only audio signal (or only video signal as seeded), the transient impacts due to the change of sampling frequency, resolution and so on in connection with either of audio or video signal can be minimized. In this embodiment, it is described the mute flags are located only in the first byte, SB0 of subpacket. However, the single mute flags such as AMUTE flag and VMUTE flag may be distributed in one or more bytes in the second byte through the eighth byte of subpacket while the complex mute flags such as AVMUTE are limited in the first byte. Also, it is to be understood that the mute flags may be located in anywhere within the subpacket. FIG. 2 and FIG. 3 represent general transmission of AVMUTE flags and AMUTE flags of General Control packet between the source device and the sink device in HDMI system. Referring to FIG. 2, transmission of AVMUTE flag is described as below. When the source device demands resolution change S2001, it sets Set_AVMUTE flag “1” of complex mute flag retained in subpacket of General Control packet and sends General Control packet to sink device S2002. The sink device parses the General Control packet and mutes audio and video signal according to the Set_AVMUTE flag S2003. In the meantime, while audio and video signal is muted, the source device changes video resolution and other setting values including synchronization, clock and so on. After the change of the video resolution is completed, the source device sets Clear_AVMUTE flag of General Control packet and sends it to the sink device S2005. And then the sink device parses the General Control packet and releases the muting of the audio and video signal S2006. Through the step as above, it is possible change video resolution by muting or releasing muting of both audio and video signals. However, it is desirable to set or clear single mute flags when it needs muting either one of audio and video signal. FIG. 3 shows mute flag control method by muting and releasing muting of only audio signal. Referring to FIG. 3, when the source device demands playback of an MP3 file which has different sampling frequency from that of the previously played MP3 file S3001, it sets Set_AMUTE flag of General Control flag which is a single audio flag to 1 and sends it to the sink device S3002. The sink device receives the General Control packet and mutes audio signal according to the Set_AMUTE flag S3003. The source device changes sampling frequency of the MP3 file while the audio signal is muted. During the changing of sampling frequency, processes in connected with video signal go on S3004. After the changing of sampling frequency is complete, the source device sets Clear_AMUTE flag to 1 of General Control packet and sends it to the sink device S3007. The sink device parses the General Control packet and releases the muting of audio signal S3008. The steps of transmitting and receiving at least one of audio mute flag and video mute flag may be prescribed as a requirement in the HDMI specification. And the test and acknowledgment procedure for the steps of transmitting and receiving audio mute flag and video mute flag can be added to HDMI CTS (Compliance Test Specification). It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. As is clear from the forgoing description, An HDMI system and mute flag controlling method according to the present invention have following advantages. It is possible to properly meet the capricious situations which may occur during the communication between the source device and the sink device due to the functional high end trend and diversification thereof by selectively muting either audio or video signal as well as muting both audio signal and video signal in HDMI system. An HDMI system and mute flag controlling method according to the present invention can reduce the transient impacts occurring during changing of system setting values, so that the interoperability between source device and sink device employing HDMI system can be enhanced and the fields which source device and sink device may be applied can be dramatically enlarged. An HDMI system and mute flag controlling method according to the present invention can achieve the above advantages by means of simple manipulations of General Control packet without creating new configuration.
|
H
|
H04
|
H04N
|
7
|
14
|
|||
11677444
|
US20070139753A1-20070621
|
CONFOCAL MICROSCOPE APPARATUS
|
ACCEPTED
|
20070608
|
20070621
|
[]
|
G02B2602
|
["G02B2602"]
|
7675676
|
20070221
|
20100309
|
359
|
385000
|
71466.0
|
NGUYEN
|
THONG
|
[{"inventor_name_last": "Nakata", "inventor_name_first": "Tatsuo", "inventor_city": "Hino-shi", "inventor_state": "", "inventor_country": "JP"}]
|
A confocal microscope apparatus comprises a first optical scanning system which obtains a scan image of a sample using a laser beam from a first laser light source, a second optical scanning system which scans specific regions of a sample with a laser beam from a second laser light source that is different from the first laser light source, thereby causing a particular phenomenon, and a beam diameter varying mechanism which can change the beam diameter of the laser beam of at least one of the first optical scanning system and the second optical scanning system. With this configuration, the apparatus further comprises an excitation light intensity distribution calculator which calculates and stores the excitation light intensity distribution along a depth direction on the sample surface from the beam diameter of the laser beam output from the beam diameter varying mechanism.
|
1. An observation method using a confocal microscope, comprising: irradiating an excitation light to a sample, while scanning the excitation light, to excite the sample, said excitation light having a predetermined intensity distribution along a depth direction of the sample; irradiating a stimulation light to the sample to stimulate a desired position of the sample, said stimulation light having an intensity distribution having a range along the depth direction which is narrower than a range of the intensity distribution of the excitation light; and detecting light emitted from the excited sample and imaging the sample which is stimulated with the stimulation light. 2. The observation method according to claim 1, wherein the imaging of the sample is carried out while changing at least one of the intensity distribution of the excitation light and the intensity distribution of the stimulation light. 3. An observation method using a confocal microscope, comprising: irradiating an excitation light to a sample, while scanning the excitation light, to excite the sample, said excitation light having a predetermined intensity distribution along a depth direction of the sample; irradiating a stimulation light to the sample to stimulate a desired position of the sample, said stimulation light having an intensity distribution having a range along the depth direction which is larger than a range of the intensity distribution of the excitation light; and detecting light emitted from the sample and imaging the sample which is stimulated with the stimulation light. 4. The observation method according to claim 3, wherein the imaging of the sample is carried out while changing at least one of the intensity distribution of the excitation light and the intensity distribution of the stimulation light. 5. A confocal microscope, comprising: an objective lens; a first irradiation system which irradiates an excitation light to a sample through the objective lens, while scanning the excitation light, to excite the sample, said excitation light having a predetermined intensity distribution along a depth direction of the sample; a second irradiation system which irradiates a stimulation light to the sample through the objective lens to stimulate a desired position of the sample, said stimulation light having an intensity distribution having a range along the depth direction which is narrower than a range of the intensity distribution of the excitation light; and a detection unit which detects light emitted from the excited sample and images the sample which is stimulated with the stimulation light. 6. The microscope according to claim 5, wherein the imaging of the sample is carried out while changing at least one of the intensity distribution of the excitation light and the intensity distribution of the stimulation light. 7. The microscope according to claim 5, further comprising: a beam diameter varying unit which varies the intensity distribution of one of the excitation light and the stimulation light along the depth direction by varying a beam diameter of the one of the excitation light and the stimulation light for a pupil diameter of the objective lens. 8. The microscope according to claim 7, wherein the beam diameter varying unit comprises a beam expander. 9. The microscope according to claim 7, wherein the excitation light is an IR pulsed laser, and the beam diameter varying unit is installed in the second irradiation system. 10. The microscope according to claim 5, wherein the first irradiation system comprises a first beam diameter varying unit which varies the intensity distribution of the excitation light along the depth direction by varying a beam diameter of the excitation light for a pupil diameter of the objective lens; and wherein the second irradiation system comprises a second beam diameter varying unit which varies the intensity distribution of the stimulation light along the depth direction by varying a beam diameter of the stimulation light for the pupil diameter of the objective lens. 11. The microscope according to claim 5, wherein the first irradiation system comprises a first laser light source which irradiates laser light used as the excitation light, and the second irradiation system comprises a second laser light source which irradiates laser light used as the stimulation light. 12. The microscope according to claim 5, wherein the second irradiation system comprises a scanning optical unit which scans the stimulation light on the sample. 13. A confocal microscope, comprising: an objective lens; a first irradiation system which irradiates an excitation light to a sample through the objective lens, while scanning the excitation light, to excite the sample, said excitation light having a predetermined intensity distribution along a depth direction of the sample; a second irradiation system which irradiates a stimulation light to the sample through the objective lens to stimulate a desired position of the sample, said stimulation light having an intensity distribution having a range along the depth direction which is larger than a range of the intensity distribution of the excitation light; and a detection unit which detects light emitted from the sample and images the sample which is stimulated with the stimulation light. 14. The microscope according to claim 13, wherein the imaging of the sample is carried out while changing at least one of the intensity distribution of the excitation light and the intensity distribution of the stimulation light. 15. The microscope according to claim 13, further comprising: a beam diameter varying unit which varies the intensity distribution of one of the excitation light and the stimulation light along the depth direction by varying a beam diameter of the one of the excitation light and the stimulation light for a pupil diameter of the objective lens. 16. The microscope according to claim 15, wherein the beam diameter varying unit comprises a beam expander. 17. The microscope according to claim 15, wherein the excitation light is an IR pulsed laser, and the beam diameter varying unit is installed in the second irradiation system. 18. The microscope according to claim 13, wherein the first irradiation system comprises a first beam diameter varying unit which varies the intensity distribution of the excitation light along the depth direction by varying a beam diameter of the excitation light for a pupil diameter of the objective lens; and wherein the second irradiation system comprises a second beam diameter varying unit which varies the intensity distribution of the stimulation light along the depth direction by varying a beam diameter of the stimulation light for the pupil diameter of the objective lens. 19. The microscope according to claim 13, wherein the first irradiation system comprises a first laser light source which irradiates laser light used as the excitation light, and the second irradiation system comprises a second laser light source which irradiates laser light used as the stimulation light. 20. The microscope according to claim 13, wherein the second irradiation system comprises a scanning optical unit which scans the stimulation light on the sample.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The invention relates to a confocal microscope apparatus which excites a specimen which has been marked with a fluorescent dye or fluorescent protein using the excitation wavelength, and detects fluorescence emitted from the specimen. 2. Description of the Related Art A scanning laser microscope has been proposed, which includes a first optical scanning system for obtaining a scan image of a sample and a second optical scanning system for causing a particular phenomenon in specific areas on the sample surface (refer to Jpn. Pat. Appln. KOKAI Publication No. 2000-275529, the entire contents of which are incorporated herein by reference). In this laser scanning microscope, a specific area on the sample surface is irradiated using a laser light source and an optical path of the first optical scanning system, thus stimulating the sample or a chemical substance injected into the sample. A specific area on the sample surface which is different from the above-mentioned area is excited using a laser light source and an optical path of the second optical scanning system, and the fluorescence is detected, and imaging is carried out. In the specification, unless stated otherwise, an optical scanning system for obtaining images of a sample is called a “first optical scanning system” and an optical scanning system for causing a particular phenomenon in specific areas of a sample is called a “second optical scanning system”. Generally, in the confocal microscope, the focal point on the sample surface and the conjugated focal point thereof are provided before the detection device, and a pinhole is provided therein. Thereby, the resolution of the sample along the depth direction is 1.22 λ/NA, and a smaller confocal effect is being utilized than when a regular microscope is used for observation. There is resolution as a result of this confocal effect, and thus a sharp cross sectional image (that is, an image to obtain a thin slice image along depth direction) can be obtained for the sample which is being scanned. When the image is taken at a high speed or when a dark sample is being used, the confocal effect is weakened by opening the pinhole (that is, enlarging a diameter of the pinhole), and the image is made bright by lowering the resolution of the fluorescence. Thus the confocal microscope has the pinhole and decreases the resolution, and thus depth-direction information can be obtained. However, since the focal depth of the sample is determined by the flux diameter of the coherent light which is irradiated on the objective lens, it is impossible to change the focal depth at the pinhole. Meanwhile, Koehler illumination is often used as the lighting to the sample by the microscope. This Koehler illumination along the thickness direction of the cross section of the sample causes almost uniform excitation. In the conventional confocal microscope described above, when the apparatus is realized by using 2 laser scanning paths and one objective lens, the excitation light intensity distribution along the depth direction on the sample surface of the laser beam for sample stimulation and the laser beam for obtaining images are almost the same since only wavelength differences is generated.
|
<SOH> BRIEF SUMMARY OF THE INVENTION <EOH>A confocal microscope apparatus according to a first aspect of the present invention is characterized by comprising: a first optical scanning system which obtains a scan image of a sample using a laser beam from a first laser light source; a second optical scanning system which scans specific regions of a sample with a laser beam from a second laser light source that is different from the first laser light source, thereby causing a particular phenomenon; and a beam diameter varying mechanism which can change the beam diameter of the laser beam of at least one of the first optical scanning system and the second optical scanning system. A confocal microscope apparatus according to a second aspect of the present invention is characterized by comprising: a first optical scanning system which scans a sample via an objective lens with incoherent light output from an incoherent light source, and detects fluorescence emitted from the sample via the objective lens; and a second optical scanning system which irradiates specific regions of the sample with laser beam output from a laser light source, thereby causing a particular phenomenon, in which the first optical scanning system further comprises a rotatable disk to obtain a confocal effect, the light output from the incoherent source scans the sample via the rotatable disk, and the fluorescence is detected via the rotatable disk. A confocal microscope apparatus according to a third aspect of the present invention is characterized by comprising: a first optical system which illuminates a sample via an objective lens with incoherent light output from an incoherent light source, and detects fluorescence emitted from the sample via the objective lens; and a second optical scanning system which irradiates specific regions of a sample with a laser beam from a laser light source, thereby causing a particular phenomenon. Advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
|
CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a Divisional Application of U.S. application Ser. No. 10/393,721 filed Mar. 21, 2003, which is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-89878, filed Mar. 27, 2002, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a confocal microscope apparatus which excites a specimen which has been marked with a fluorescent dye or fluorescent protein using the excitation wavelength, and detects fluorescence emitted from the specimen. 2. Description of the Related Art A scanning laser microscope has been proposed, which includes a first optical scanning system for obtaining a scan image of a sample and a second optical scanning system for causing a particular phenomenon in specific areas on the sample surface (refer to Jpn. Pat. Appln. KOKAI Publication No. 2000-275529, the entire contents of which are incorporated herein by reference). In this laser scanning microscope, a specific area on the sample surface is irradiated using a laser light source and an optical path of the first optical scanning system, thus stimulating the sample or a chemical substance injected into the sample. A specific area on the sample surface which is different from the above-mentioned area is excited using a laser light source and an optical path of the second optical scanning system, and the fluorescence is detected, and imaging is carried out. In the specification, unless stated otherwise, an optical scanning system for obtaining images of a sample is called a “first optical scanning system” and an optical scanning system for causing a particular phenomenon in specific areas of a sample is called a “second optical scanning system”. Generally, in the confocal microscope, the focal point on the sample surface and the conjugated focal point thereof are provided before the detection device, and a pinhole is provided therein. Thereby, the resolution of the sample along the depth direction is 1.22 λ/NA, and a smaller confocal effect is being utilized than when a regular microscope is used for observation. There is resolution as a result of this confocal effect, and thus a sharp cross sectional image (that is, an image to obtain a thin slice image along depth direction) can be obtained for the sample which is being scanned. When the image is taken at a high speed or when a dark sample is being used, the confocal effect is weakened by opening the pinhole (that is, enlarging a diameter of the pinhole), and the image is made bright by lowering the resolution of the fluorescence. Thus the confocal microscope has the pinhole and decreases the resolution, and thus depth-direction information can be obtained. However, since the focal depth of the sample is determined by the flux diameter of the coherent light which is irradiated on the objective lens, it is impossible to change the focal depth at the pinhole. Meanwhile, Koehler illumination is often used as the lighting to the sample by the microscope. This Koehler illumination along the thickness direction of the cross section of the sample causes almost uniform excitation. In the conventional confocal microscope described above, when the apparatus is realized by using 2 laser scanning paths and one objective lens, the excitation light intensity distribution along the depth direction on the sample surface of the laser beam for sample stimulation and the laser beam for obtaining images are almost the same since only wavelength differences is generated. BRIEF SUMMARY OF THE INVENTION A confocal microscope apparatus according to a first aspect of the present invention is characterized by comprising: a first optical scanning system which obtains a scan image of a sample using a laser beam from a first laser light source; a second optical scanning system which scans specific regions of a sample with a laser beam from a second laser light source that is different from the first laser light source, thereby causing a particular phenomenon; and a beam diameter varying mechanism which can change the beam diameter of the laser beam of at least one of the first optical scanning system and the second optical scanning system. A confocal microscope apparatus according to a second aspect of the present invention is characterized by comprising: a first optical scanning system which scans a sample via an objective lens with incoherent light output from an incoherent light source, and detects fluorescence emitted from the sample via the objective lens; and a second optical scanning system which irradiates specific regions of the sample with laser beam output from a laser light source, thereby causing a particular phenomenon, in which the first optical scanning system further comprises a rotatable disk to obtain a confocal effect, the light output from the incoherent source scans the sample via the rotatable disk, and the fluorescence is detected via the rotatable disk. A confocal microscope apparatus according to a third aspect of the present invention is characterized by comprising: a first optical system which illuminates a sample via an objective lens with incoherent light output from an incoherent light source, and detects fluorescence emitted from the sample via the objective lens; and a second optical scanning system which irradiates specific regions of a sample with a laser beam from a laser light source, thereby causing a particular phenomenon. Advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention. FIG. 1 is a schematic diagram of a confocal microscope apparatus according to a first embodiment of the invention; FIG. 2 is a view showing a structural example of a first beam diameter varying mechanism and a second bean diameter varying mechanism; FIG. 3 is a schematic diagram of a confocal microscope apparatus according to a second embodiment of the invention; FIG. 4 is a view showing an example of a rotatable disk used in the invention; and FIG. 5 is a view schematically showing a nerve tissue observation. DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described with reference to the drawings. First Embodiment FIG. 1 is a schematic diagram of a confocal microscope apparatus according to a first embodiment of the invention. In FIG. 1, the confocal microscope apparatus comprises: a first optical scanning system 100 for observation (or for obtaining images) which scans a focal surface of a sample 134 with a laser beam from a first laser light source 101; and a second optical scanning system 200 for radiating the laser beam output from the second laser light source 201 onto an optional position on the sample 134, and splitting the caged reagent (i.e. for sample stimulation). An optical path of the first optical scanning system 100 and an optical path of the second optical scanning system 200 meet at a dichroic mirror 120. As a result, the first optical scanning system 100 and the second optical scanning system 200 share an objective lens 132. In the first optical scanning system 100 and the second optical scanning system 200, the coherent light output from the first laser light source 101 arrives at the dichroic mirror 120 by way of a first beam diameter varying mechanism 102 and a first optical scanning unit 104. Also, the coherent light output from the second laser light source 201 reaches the dichroic mirror 120 by way of a beam diameter varying mechanism 202 and a second optical scanning unit 203. In addition, the first beam diameter varying mechanism 102 and the second beam diameter varying mechanism 202 are connected electrically or indirectly to an excitation light intensity calculator 160. As a result, the excitation light intensity calculator 160 can obtain beam diameter information of the beams output from the first beam diameter varying mechanism 102 and the second beam diameter varying mechanism 202. The first beam diameter varying mechanism 102 and the second beam diameter varying mechanism 202 may, as shown in FIG. 2 for example, include a plurality of mechanisms, which changes the flux diameter such as beam expanders, on a rotatable turret. Also mechanisms, in which optical elements such as a plurality of lenses are combined, and the flux diameter is changed while the coherence of the laser is maintained (for example, zoom mechanism), may be adopted as the first beam diameter varying mechanism 102 and the second beam diameter varying mechanism 202. The operation of the confocal microscope apparatus according to the first embodiment, which has the above-described configuration, will be described. The first optical scanning system 100 and the second optical scanning system 200 are used for radiating a coherent light at an optional (desired) position on the sample 134. Specifically, this is as described below. That is, the flux diameter of the coherent light generated from the first laser light source 101 and the second laser light source 201 respectively, are varied (adjusted) with the first beam diameter varying mechanism 102 and the second beam diameter varying mechanism 202. The light beam output from the first beam diameter varying mechanism 102 passes a dichroic mirror 150, and is arbitrarily deflected to an XY direction by each of scanning mirrors 104a and 104b of the first optical scanning unit 104. The deflected light beam is reflected at the mirror 106 after passing through a relay lens 105, and is then irradiated onto the dichroic mirror 120. Meanwhile, the light beam output from the second beam diameter varying mechanism 202 is suitably deflected in an XY direction by each of scanning mirrors 203a and 203b of the second optical scanning unit 203. The deflected light beam passes through the relay lens 204 and is irradiated onto the dichroic mirror 120, and the optical path is deflected at the dichroic mirror 120. In addition, the coherent light from the dichroic mirror 120 is irradiated onto an image formation lens 130. By changing the flux diameters of the laser beams from the first laser light source and the second laser light source at the first beam diameter varying mechanism 102 and the second beam diameter varying mechanism 202 with respect to the pupil diameter of the objective lens 132, the width of the excitation light distribution (and/or the intensity distribution) along the depth direction on the surface of the sample 134 corresponding to each of the optical scanning systems can be changed. The light beam that has passed through the image formation lens 130 reaches the objective lens 132, passes through the objective lens 132 and is focused on an arbitrary cross section 138 of the sample 134 which is mounted on a stage 136. The stage 136 is movable along the XY horizontal direction and the height direction (Z axis direction—the direction of the arrow in FIG. 1). As described above, when the sample 134 is being scanned, in accordance with the application, a particular field may be scanned by each of the scanning mirrors 203a and 203b or it may be kept still and irradiated in spots. Further by skipping each of the scanning mirrors 203a and 203b momentarily, the field can be irradiated in spots at a number of arbitrary positions from moment to moment. Meanwhile, the coherent light generated from the first laser light source 101 is transmitted by the dichroic mirror 150 as described above, and it is deflected by each of the scanning mirrors 104a and 104b of the first optical scanning unit 104. When light beam is irradiated on the sample 134 by the first optical scanning system 100, the fluorescent marker chemical is excited and fluorescence is generated. The fluorescence from the sample 134 takes the opposite direction of the optical path of the light irradiated on the sample 134 and passes from the objective lens 132 by way of the image formation lens 130, the dichroic mirror 120, the first optical scanning unit 104, the relay lens 103, each of the scanning mirrors 104a and 104b and arrives at the dichroic mirror 150, and at the dichroic mirror 150. The fluorescence is reflected and incident to a photometry filter 140. The light beam is incident to the photometry filter 140 and only the fluorescent wavelength from the sample 134 is selected, and the light beam from the sample 134 having only the fluorescence wavelength is focused at a surface of the pinhole 144 by a lens 142. The fluorescence, which has passed through the pinhole 144, is measured by a photoelectric conversion device 146. The excitation light intensity calculator 160 calculates the excitation light intensity distribution on the sample surface by inputting the information on the beam diameter of the beam output by the first beam diameter varying mechanism 102 and the second beam diameter varying mechanism 202 and the performance (specification) of the objective lens being used at the time. It also has other functions such as outputting values, which have already been stored in a memory, to interfaces such as a computer or a display (not shown in the figure). According to the confocal microscope apparatus of the first embodiment of the invention as mentioned above, when the sample 134 is observed and recorded by the first optical scanning system 100, by irradiating coherent light on the sample 134 by the second optical scanning system 200, the dynamics (chemical reactions) of sample 134 which are caused by the coherent light irradiation by the second optical scanning system 200 can be adjusted by the first optical scanning system 100. In this case, in the first embodiment, the excitation light distribution along the depth direction on the sample surface by the first optical scanning system 100 and the second optical scanning system 200 are independently set by the first beam diameter varying mechanism 102 and the second beam diameter varying mechanism 202. Accordingly, even if the excitation light distribution is narrow for the field of the sample being excited by the second optical scanning system, that is, even in the case where a large area of the sample along the thickness direction is excited, by broadening the excitation light distribution of the first optical scanning system, it is possible to carry out observation. Also, unlike the case described above, at the second optical scanning system, a wide field of the sample along the thickness direction is stimulated, and at the first optical scanning system, the excitation light distribution field along the thickness direction is narrowed, and thus the cross section 138 of the sample can be observed with high resolution. The first embodiment may be configured such that an IR pulse laser is used as the first laser light source 101, and a fluorescent image is obtained by two photon absorption. In this case, the two photon absorption phenomenon occurs only at the position where the image is formed and theoretically the pinhole 144 is unnecessary. Also, because the dichroic mirror 150 can transmit the IR pulse laser, reflect the visible fluorescence and lead it to the photoelectric converter 146, this embodiment has the property of reflecting short wavelengths. It may also be configured such that the beam diameter varying mechanism 102 is not used. As described above, by using an IR pulse laser as the first laser light source 101, the configuration of the first optical scanning system 100 is simplified. In addition, even in the case where the first beam diameter varying mechanism 102 is not used, the width of the excitation light distribution along the depth direction on the sample surface of the optical scanning system 1 becomes narrow than the excitation light distribution along the depth direction of the second optical scanning system 200 due to the two photon absorption phenomenon. Further, in the case where the thickness of the sample to be stimulated is to be changed, the width of the excitation light distribution of the second optical scanning system 200 can be made smaller by the second beam diameter varying mechanism 202. Second Embodiment A confocal microscope according to a second embodiment of the invention is described with reference to FIG. 3. FIG. 3 is a schematic diagram of the confocal microscope apparatus according to the second embodiment of the invention. The second optical scanning system 200 of FIG. 3 is the same as that of the first embodiment, and has been assigned the same reference numbers and thus detailed descriptions thereof are omitted. In the second embodiment, a first optical scanning system 100′ has a incoherent light source such as a mercury light source, a halogen light source, or an LED light source as a light source 301. An optical lens 302, a polarizing plate 303 and a polarizing beam splitter (PBS) 304 are arranged on an optical path of a light beam emitted from the light source 301. A rotatable disk 305, a first image formation lens 307, a quarter wave plate 308, and objective lens 309 are arranged on a reflection optical path of the PBS 304, and a light beam from the light source is incident to a sample 310, which is mounted on a stage 318, by way of these. The rotatable disk 305 is connected to a shaft of a motor (not shown) via a rotation shaft 306, and rotates at a predetermined rotation speed. The rotatable disk 305 has linear transmit portions through which light passes and linear shield portions which shield light are alternately arranged. In addition, the line width of the shield portion is wider than that of the transmit portion, and for example, the ratio of the width of the shield portion to that of the transmit portion is 1:9 (refer to FIG. 4). If the width of the portion through which light passes is W, and as is the case with the pinhole, assuming that magnification with which the specimen image is projected onto the disk is M, the wavelength of the light is λ, and the numerical aperture of the objective lens is NA, W=kλM/NA where k is a coefficient and a value in the range of 0.5 to 1 is often used for k. Also, a CCD camera 312 is arranged on the transmission optical path of the PBS 304 via a second image formation lens 311. A monitor 313 for observing the image taken by the CCD camera 312 is connected to the camera 312. The operation of the confocal microscope of the second embodiment having the above configuration will be described in the following. The light beam output from the light source 301 passes through the optical lens 302, and at the polarizing plate 303 it is transformed to linearly polarized light having only a predetermined polarization, and then input into the PBS 304. The PBS 304 reflects the deflected light beam in the direction in which the beam has passed through the polarizing plate and a light in a direction parallel thereto is transmitted. The light beam reflected at the PBS 304 is input into the rotatable disk 305 which rotates at a predetermined speed. The light beam passing through the transmit portion of the rotatable disk 305 passes through the first image formation lens 307 and becomes circularly polarized at the quarter wave plate 308, and is focused on an arbitrary cross section 320 of the sample 310 with the objective lens 309 to be irradiated on the sample 310. The light beam reflected by the sample 310 passes through the objective lens 309, and at the quarter plate 308 it becomes linearly polarized light which is orthogonal to that at the time of input, thereby focusing the image of the sample 310 on the rotatable disk 305, via the second imaging lens 311. The focused component of the formed image formed on the rotatable disk 305 passes through the transmit portion of the rotatable disk 305. The component passing through the rotatable disk 305 is transmitted by the PBS 304, and arrives at the CCD camera 312 by way of the second image formation lens 311. The specimen image is formed on the image formation surface (image pickup surface). If a particular moment when the sample 310 is being observed is considered, a line is projected on the sample 310 along a particular direction as shown in FIG. 4. In this situation, in the case where the light beam reflected from the sample 310 in this state is focused on the rotatable disk 305, a line is projected on the rotatable disk 305 for the portion of the sample 310 which is in focus. However, for the unfocused portion, the image that is projected on the rotatable disk 305 is blurred, and thus most of the unfocused image cannot be transmitted. Accordingly, only images which are in focus are transmitted to the rotatable disk 305. When the rotatable disk 305 is not rotating, the situation is not changed and the image is simply one in which the sample and the line overlap. However, by rotating the rotatable disk 305, the line which includes the transmit portion and the shield portion moves while changing its direction on the sample 310, and thus there is uniformity, the line image disappears and an image which is in focus can be observed. Thus, if the rotation of the rotatable disk 305 is sufficiently fast with respect to the exposure time of the CCD camera 312, the focused image can be picked up by the CCD camera 312 and observed at the monitor 313. For example, if the CCD camera 312 has a TV rate as a usual, the exposure time is 1/60 second or 1/30 second. Therefore, the number of rotations of the rotatable disk 305 during the exposure time should be about 1800 rpm at which half revolutions occur. The excitation light distribution along the depth direction on the surface of the sample 310 of the first optical scanning system 100′ at this time is the same as the light distribution of Koehler illumination of the microscope in the longitudinal direction of the slit. At the width direction of the slit, the distribution is the same as the second optical scanning system. Accordingly, excitation light distribution along the depth direction on the sample surface of the first optical scanning system is a distribution of which both longitudinal direction and width direction distributions are combined. It is possible to change the excitation light intensity distribution along the depth direction, by varying the width of the slit and the space between the slits of the rotatable disk 305. In the second embodiment, by detecting the dynamic change which caused reaction of the light radiated by the second optical scanning system which has been shown in the first embodiment using the first optical scanning system 100′, the excitation light distribution along the depth direction on the surface of the first and second samples can be different. Accordingly, a wider field of measurement is possible in the first optical scanning system 100′ than the stimulation field in the second optical scanning system 200. Particularly in nervous system measurements, in order to catch movements of the nerve which extend along the thickness direction of the sample, it is necessary to obtain the images with high speed. Usually, with the confocal microscope apparatus, in order to increase the width of the excitation light distribution along the depth direction on the surface of the sample, if the sample is extends along the thickness direction, the image cannot be captured with one measurement. As a result, as in the second embodiment, by reducing the width of the excitation light distribution along the depth direction on the surface of the sample, image measurements for wider fields can be taken. Accordingly, the second embodiment may have a configuration in which the rotatable disk 305 is omitted. Also the rotatable disk is not limited to the structure shown in FIG. 4. Provided that the confocal effect can be obtained, any configuration or structure can be used. For example, the rotatable disk may be one having pinholes formed therein, and it can be a reflection type rotatable disk rather than the transmit type of the above-described embodiment. In addition, in the second embodiment, the second beam diameter varying mechanism 202 is not necessarily needed. However, if the second embodiment has the second beam diameter varying mechanism 202, it is possible to change the proportion of the first cross section and the second cross section, and by fine adjustment of the field for obtaining images and the portion for stimulation, the degree of freedom of the experiment (and/or observation) is increased. In addition, when the second beam diameter varying mechanism 202 is provided, it is preferable that the excitation light intensity distribution calculator 160 is provided as in the case of the first embodiment. Also, in the above-described configuration, by the first optical scanning system 100′ having an optical microscope system with Koehler illumination, it becomes possible for the image to be obtained in a wider excitation field. In this case, the rotatable disk 305 is unnecessary. In the above-described second embodiment, the PBS 304 may be replaced with a dichroic mirror. In this case, the light beam from the light source is reflected at the dichroic mirror, and the fluorescence from the sample passes through the dichroic mirror. Thus the optical path of the optical excitation system and that of the optical measurement system can be separated, and as a result the polarizing plate 303 is unnecessary. Applications of the confocal microscope apparatus of each of the above-described embodiments include for example, the application in the field of cell research in which the cell is locally excited and reactions at the excited regions are observed. In the method known as the uncaged method, by locally exciting the cell, the concentration of the activated material is changed. When this change in concentration is to be measured, by measuring peripheral portions other than the locally excited regions simultaneously, the internal functions of the cell can be analyzed. In the photo-bleach method, by locally exciting the cell, the excited regions are discolored. The phenomenon is seen where due to migration of proteins from the periphery, over time color returns to the region which has been discolored. Accordingly, measurements for both the locally stimulated region and the peripheral portions are necessary. An example thereof is shown using FIG. 5. FIG. 5 is a schematic view showing a nerve tissue observation. For example, when ions transmitted on an axis cylinder 3 from a cell body 1 to a cell body 2 are observed with the caged fluorescent dyes introduced into the cell body 1 as a probe, first a laser beam for stimulating a sample is radiated on a focal point surface 4 of the cell body 1. Next, subsequent changes are observed with a laser beam for sample observation. However, the excitation light intensity distribution of the laser beam for sample observation 6 along the depth direction usually has the same depth as the excitation light intensity distribution 5 of the laser beam for sample stimulation. Thus, in the prior art, the fluorescent dye which transmits the axis cylinder 3 and is not within that distribution field cannot be observed because it is not exposed to excitation light. To the contrary, in each of the embodiments of the invention, the excitation light intensity distribution along the depth direction, of the laser beam for sample stimulation and the laser beam for obtaining images on the surface of the sample are each independently varied, thus solving the problem of the prior art. The inventions described in the following are extracted from the embodiments described below. The above-described embodiments do not limit the invention. Accordingly various modifications may be made within the scope of the general inventive concept of the invention. The confocal microscope apparatus according to a first aspect of the present invention is characterized by comprising: a first optical scanning system which obtains a scan image of a sample using a laser beam from a first laser light source; a second optical scanning system which scans specific regions of a sample with a laser beam from a second laser light source that is different from the first laser light source, thereby causing a particular phenomenon; and a beam diameter varying mechanism which can change the beam diameter of the laser beam of at least one of the first optical scanning system and the second optical scanning system. By combining the optical laser system and the laser scanning microscope, it becomes possible to change the width of measurement by using differences in the excitation intensity distribution along the depth direction on the surface of the sample. Specifically, this is done in the following manner. Conventionally, when movement of the sample is being analyzed, it is of course desirable for the field of excitation and the field for obtaining the images to be different, and also for the excitation light intensity distribution on the sample surface of the laser beam for sample stimulation along the depth direction and the excitation light intensity distribution on the sample surface of the laser beam for obtaining images along the depth direction to be different from each other. In addition, it is desirable for the width of the excitation light intensity distribution along the depth direction to be intentionally made small. In the first aspect, a beam diameter varying mechanism for changing the beam diameter of the laser beam is provided to the output exit for the laser beam of each of the optical scanning systems. When the flux diameter is reduced by this beam diameter varying mechanism, the numerical aperture of the objective lens is smaller than in the case where the flux diameter is large. Consequently, the width of the excitation light intensity distribution along the depth direction on the surface of the sample can be reduced without changing the objective lens. Further, by providing each of the optical systems with the beam diameter varying mechanism, the excitation light intensity distribution along the depth direction of the sample surface of each of the optical systems can be changed independently. Also, the excitation light distribution along the depth direction on the sample surface can be changed intentionally. The confocal microscope apparatus according to a second aspect of the present invention is characterized by comprising: a first optical scanning system which scans a sample via an objective lens with incoherent light output from an incoherent light source, and detects fluorescence emitted from the sample via the objective lens; and a second optical scanning system which irradiates specific regions of the sample with laser beam output from a laser light source, thereby causing a particular phenomenon, in which the first optical scanning system further comprises a rotatable disk to obtain a confocal effect, the light output from the incoherent source scans the sample via the rotatable disk, and the fluorescence is detected via the rotatable disk. The optical laser system and the disk type confocal microscope apparatus are combined, so that it becomes possible to change the width for measurement due to differences in the excitation intensity distribution along the depth direction on the surface of the sample. The confocal microscope apparatus according to a third aspect of the present invention is characterized by comprising: a first optical system which illuminates a sample via an objective lens with incoherent light output from an incoherent light source, and detects fluorescence emitted from the sample via the objective lens; and a second optical scanning system which irradiates specific regions of a sample with a laser beam from a laser light source, thereby causing a particular phenomenon. The optical laser system and the microscope of Koehler illumination are combined, so that it becomes possible to change the width of measurement due to differences in the excitation intensity distribution along the depth direction on the surface of the sample. Preferred embodiments of the confocal microscope described above are as described in the following. Each of the embodiments may be used alone or may used in combination. (1) The second optical scanning system further comprises a beam diameter varying mechanism, which changes a beam diameter of the laser beam of the laser light source. (2) An excitation light intensity distribution calculator which calculates and stores the excitation light intensity distribution along a depth direction on the sample surface from the beam diameter of the laser beam output from the beam diameter varying mechanism is further provided. (3) The first laser light source is an IR pulsed laser, and the beam diameter varying mechanism is provided to the second scanning optical system. (4) In (3), a depth direction intensity distribution calculator which calculates an intensity distribution along a depth direction of the laser light beam output from the beam diameter varying mechanism on the sample surface is further provided. (5) The incoherent light source includes a lamp or an LED light source. The observation method according to the fourth aspect of the invention is characterized by comprising: irradiating an excitation light to a sample to excite the sample; irradiating an light to cause the particular phenomenon to a desired position; and imaging by detecting a light from the excited sample, in which said irradiating the excitation light includes adjusting an intensity distribution of the excitation light along a depth direction on the surface. The observation method according to the fifth aspect of the invention is characterized by comprising: irradiating an excitation light to a sample to excite the sample; irradiating an light to cause the particular phenomenon to a desired position; and imaging by detecting a light from the excited sample, in which said irradiating the sample includes adjusting an intensity distribution of the light to cause the particular phenomena along a depth direction on the surface. The observation method according to the sixth aspect of the invention is characterized by comprising: irradiating an excitation light to a sample via a rotatable disk to acquire a fluorescent image of the sample by a disk scanning; and irradiating an light to cause the particular phenomenon to a desired position. With this configuration, it is preferable that the irradiating the light includes adjusting an intensity distribution of the excitation light along a depth direction on the surface. According to the present invention, by independently changing the intensity distribution along the depth direction on the sample surface of the excitation light in the optical system for sample excitation and for obtaining images, it becomes possible to do dynamic analysis of different three-dimensional spaces. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
|
G
|
G02
|
G02B
|
26
|
02
|
|||
11895286
|
US20090069347A1-20090312
|
2-phenoxy pyrimidinone analogues
|
ACCEPTED
|
20090225
|
20090312
|
[]
|
C07D47302
|
["C07D47302", "A61K31522", "A61K31519", "C07D47104", "C07D51304", "A61P2900", "A61P1300", "A61P2514", "A61P500"]
|
8003656
|
20070822
|
20110823
|
514
|
263300
|
59557.0
|
MOORE
|
SUSANNA
|
[{"inventor_name_last": "Bakthavatchalam", "inventor_name_first": "Rajagopal", "inventor_city": "Madison", "inventor_state": "CT", "inventor_country": "US"}, {"inventor_name_last": "Capitosti", "inventor_name_first": "Scott M.", "inventor_city": "Middletown", "inventor_state": "CT", "inventor_country": "US"}, {"inventor_name_last": "Xu", "inventor_name_first": "Jianjun", "inventor_city": "Branford", "inventor_state": "CT", "inventor_country": "US"}, {"inventor_name_last": "Chenard", "inventor_name_first": "Bertrand L.", "inventor_city": "Waterford", "inventor_state": "CT", "inventor_country": "US"}, {"inventor_name_last": "Ghosh", "inventor_name_first": "Manuka", "inventor_city": "Madison", "inventor_state": "CT", "inventor_country": "US"}, {"inventor_name_last": "Blum", "inventor_name_first": "Charles A.", "inventor_city": "Westbrook", "inventor_state": "CT", "inventor_country": "US"}]
|
2-Phenoxy pyrimidinone analogues are provided, of the Formula: wherein variables are as described herein. Such compounds are ligands that may be used to modulate specific receptor activity in vivo or in vitro, and are particularly useful in the treatment of conditions associated with pathological receptor activation in humans, domesticated companion animals and livestock animals. Pharmaceutical compositions and methods for using such compounds to treat such disorders are provided, as are methods for using such ligands for receptor localization studies.
|
1. A compound of the formula: or a pharmaceutically acceptable salt or hydrate thereof, wherein: represents a fused 5- or 6-membered heteroaryl that contains 1, 2 or 3 heteroatoms independently chosen from O, N and S, with the remaining ring atoms being carbon, wherein the fused heteroaryl is substituted with from 0 to 3 substituents independently chosen from amino, hydroxy, C1-C6alkyl, C1-C6hydroxyalkyl, (C3-C7cycloalkyl)C0-C2alkyl, C1-C6haloalkyl, C1-C6alkoxy, C2-C6alkyl ether, C1-C6alkanoyloxy, C1-C6alkylsulfonylamino, C1-C6alkanonylamino, and mono- or di-(C1-C6alkyl)amino; Ar is phenyl or a 5- or 6-membered heteroaryl, each of which is substituted with from 0 to 4 substituents that are independently chosen from halogen, cyano, amino, nitro, C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, C1-C6haloalkyl, C1-C6hydroxyalkyl, C1-C6alkoxy, C1-C6haloalkoxy, (C3-C7cycloalkyl)C0-C4alkyl, and mono- or di-(C1-C6alkyl)amino; and R3 represents from 0 to 4 substituents that are independently chosen from halogen, hydroxy, cyano, amino, nitro, C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, C1-C6haloalkyl, C1-C6hydroxyalkyl, C1-C6alkoxy, C1-C6haloalkoxy, (C3-C7cycloalkyl)C0-C4alkyl, mono- or di-(C1-C6alkyl)amino, and mono- or di-(C1-C6alkyl)aminosulfonyl. 2. A compound or salt or hydrate thereof according to claim 1, wherein the compound has the formula: wherein: represents a fused 5- or 6-membered heteroaryl that contains 1, 2 or 3 heteroatoms independently chosen from O, N and S, and that is substituted with from 0 to 2 substituents independently chosen from amino, hydroxy, C1-C6alkyl, C1-C6hydroxyalkyl, (C3-C7cycloalkyl)C0-C2alkyl, C1-C6haloalkyl, C1-C6alkoxy, C2-C6alkyl ether, C1-C6alkanoyloxy, C1-C6alkylsulfonylamino, C1-C6alkanonylamino, and mono- or di-(C1-C6alkyl)amino; X is N or CH that is optionally substituted with a substituent represented by R1; R1 represents from 0 to 3 substituents independently chosen from halogen, cyano, amino, nitro, C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, C1-C6haloalkyl, C1-C6hydroxyalkyl, C1-C6alkoxy, C1-C6haloalkoxy, (C3-C7cycloalkyl)C0-C4alkyl, and mono- or di-(C1-C6alkyl)amino; and R3 represents from 0 to 3 substituents independently chosen from halogen, hydroxy, cyano, amino, nitro, C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, C1-C6haloalkyl, C1-C6hydroxyalkyl, C1-C6alkoxy, C1-C6haloalkoxy, (C3-C7cycloalkyl)C0-C4alkyl, mono- or di-(C1-C6alkyl)amino, and mono- or di-(C1-C6alkyl)aminosulfonyl. 3. A compound or salt or hydrate thereof according to claim 1, wherein is a 5-membered heteroaryl that is substituted with from 0 to 2 substituents independently chosen from C1-C4alkyl, (C3-C5cycloalkyl)C0-C2alkyl and C1-C4haloalkyl. 4. A compound or salt or hydrate thereof according to claim 3, wherein is wherein R2 is hydrogen, C1-C4alkyl, C1-C4haloalkyl or C3-C5cycloalkyl. 5. A compound or salt or hydrate thereof according to claim 1, wherein is a 6-membered heteroaryl that is substituted with from 0 to 3 substituents independently chosen from hydroxy, C1-C6alkyl, (C3-C7cycloalkyl)C0-C2alkyl, C1-C6haloalkyl, C1-C6hydroxyalkyl, C1-C6alkoxy, mono-(C1-C6alkyl)amino, C1-C6alkanoylamino or C1-C6alkylsulfonylamino. 6. A compound or salt or hydrate thereof according to claim 5, wherein is wherein R4 represents from 1 to 3 substituents independently chosen from hydroxy, C1-C4alkyl, (C3-C5cycloalkyl)C0-C2alkyl, C1-C4haloalkyl, C1-C4hydroxyalkyl, C1-C4alkoxy, mono-(C1-C4alkyl)amino, C1-C4alkanoylamino or C1-C4alkylsulfonylamino. 7. A compound or salt or hydrate thereof according to claim 2, wherein R1 represents from 1 to 3 substituents independently chosen from halogen, cyano, C1-C4alkyl and C1-C4haloalkyl. 8. A compound or salt or hydrate thereof according to claim 7, wherein one substituent represented by R1 is a halogen or cyano at the para position. 9. A compound or salt or hydrate thereof according to claim 7, wherein R1 represents exactly one substituent. 10. A compound or salt or hydrate thereof according to claim 1, wherein R3 represents from 1 to 3 substituents independently chosen from halogen, cyano, C1-C6alkyl, C1-C6haloalkyl and C1-C6alkoxy. 11. A compound or salt or hydrate thereof according to claim 2, wherein the compound has the formula: wherein: R2 is hydrogen, C1-C4alkyl, C1-C4haloalkyl or C3-C5cycloalkyl; R3 represents from 1 to 3 substituents independently chosen from halogen, cyano, C1-C4alkyl, C1-C4haloalkyl and C1-C4alkoxy; and R5 is halogen or CN. 12. A compound or salt or hydrate thereof according to claim 2, wherein the compound has the formula: wherein: R3 represents from 1 to 3 substituents independently chosen from halogen, cyano, C1-C4alkyl, C1-C4haloalkyl and C1-C4alkoxy; and R5 is halogen or CN. 13. A compound or salt or hydrate thereof according to claim 2, wherein the compound has the formula: wherein: R2 is hydrogen, C1-C4alkyl, C1-C4haloalkyl or C3-C5cycloalkyl; R3 represents from 1 to 3 substituents independently chosen from halogen, cyano, C1-C4alkyl, C1-C4haloalkyl and C1-C4alkoxy; and R5 is halogen or CN. 14. A compound or salt or hydrate thereof according to claim 2, wherein the compound has the formula: wherein: R3 represents from 1 to 3 substituents independently chosen from halogen, cyano, C1-C4alkyl, C1-C4haloalkyl and C1-C4alkoxy; R4 represents from 0 to 2 substituents independently chosen from hydroxy, C1-C4alkyl, (C3-C5cycloalkyl)C0-C2alkyl, C1-C4haloalkyl, C1-C4hydroxyalkyl, C1-C4alkoxy, mono-(C1-C4alkyl)amino, C1-C4alkanoylamino or C1-C4alkylsulfonylamino; and R5 is halogen or CN. 15. A compound or salt or hydrate thereof according to claim 1, wherein the compound is: 1-(4-bromophenyl)-9-methyl-2-(2,3,4-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-chlorophenyl)-2-(2,3-difluorophenoxy)-9-methyl-1,9-dihydro-6H-purin-6-one; 1-(4-chlorophenyl)-2-(2,4-difluorophenoxy)-9-methyl-1,9-dihydro-6H-purin-6-one; 1-(4-chlorophenyl)-2-[2-fluoro-3-(trifluoromethyl)phenoxy]-9-methyl-1,9-dihydro-6H-purin-6-one; 1-(4-chlorophenyl)-9-methyl-2-(2,3,4-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-chlorophenyl)-9-methyl-2-(2,3,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-chlorophenyl)-9-methyl-2-(2,3,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-chlorophenyl)-9-methyl-2-(2,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-chlorophenyl)-9-methyl-2-(2,4,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-chlorophenyl)-9-methyl-2-(3,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-fluorophenyl)-2-[2-fluoro-3-(trifluoromethyl)phenoxy]-9-methyl-1,9-dihydro-6H-purin-6-one; 1-(4-fluorophenyl)-2-[3-fluoro-5-(trifluoromethyl)phenoxy]-9-methyl-1,9-dihydro-6H-purin-6-one; 1-(4-fluorophenyl)-9-methyl-2-(2,3,4-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-fluorophenyl)-9-methyl-2-(2,3,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-fluorophenyl)-9-methyl-2-(2,3,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-fluorophenyl)-9-methyl-2-(2,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-fluorophenyl)-9-methyl-2-(2,4,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 1-(4-fluorophenyl)-9-methyl-2-[3-(trifluoromethyl)phenoxy]-1,9-dihydro-6H-purin-6-one; 1-(6-chloropyridin-3-yl)-9-methyl-2-(3,4,5-trifluorophenoxy)-1H-purin-6(9H)-one; 2-(2,3-difluoro-4-methoxyphenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one; 2-(2,3-difluoro-4-methoxyphenoxy)-9-ethyl-1-(4-fluorophenyl)-1,9-dihydro-6H-purin-6-one; 2-(2,3-difluorophenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one; 2-(2,3-difluorophenoxy)-9-ethyl-1-(4-fluorophenyl)-1,9-dihydro-6H-purin-6-one; 2-(2,3-dimethoxyphenoxy)-3-(4-fluorophenyl)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one 2-(2,3-dimethylphenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one; 2-(2,4-difluorophenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one; 2-(2,4-difluorophenoxy)-3-(4-fluorophenyl)pyrido[3,2-d]pyrimidin-4(3H)-one; 2-(2,4-difluorophenoxy)-9-ethyl-1-(4-fluorophenyl)-1,9-dihydro-6H-purin-6-one; 2-(2,6-dimethylphenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one; 2-(2-chloro-4-fluorophenoxy)-1-(4-chlorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one; 2-(2-chloro-4-fluorophenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one; 2-(2-ethylphenoxy)-3-(4-fluorophenyl)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one; 2-(4-chloro-2-fluorophenoxy)-1-(4-chlorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one; 2-(4-chloro-2-fluorophenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one; 2-(4-chloro-2-fluorophenoxy)-3-(4-chlorophenyl)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one; 2-(4-chloro-2-fluorophenoxy)-3-(4-fluorophenyl)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one; 2-(4-chloro-2-fluorophenoxy)-9-ethyl-1-(4-fluorophenyl)-1,9-dihydro-6H-purin-6-one; 2,3-difluoro-4-{[1-(4-fluorophenyl)-9-methyl-6-oxo-6,9-dihydro-1H-purin-2-yl]oxy}benzonitrile; 2-[2-chloro-3-(trifluoromethyl)phenoxy]-3-(4-fluorophenyl)pyrido[3,2-d]pyrimidin-4(3H)-one; 3-(4-chlorophenyl)-2-(2,4-difluorophenoxy)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one; 3-(4-chlorophenyl)-7-methyl-2-(2,3,4-trifluorophenoxy)thieno[3,2-d]pyrimidin-4(3H)-one; 3-(4-fluorophenyl)-2-(2,3,4-trifluorophenoxy)pyrido[3,2-d]pyrimidin-4(3H)-one; 3-(4-fluorophenyl)-2-(2-isopropylphenoxy)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one; 3-(4-fluorophenyl)-2-(2-methoxyphenoxy)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one; 3-(4-fluorophenyl)-2-[3-(trifluoromethyl)phenoxy]pyrido[3,2-d]pyrimidin-4(3H)-one; 3-(4-fluorophenyl)-2-[3-fluoro-5-(trifluoromethyl)phenoxy]pyrido[3,2-d]pyrimidin-4(3H)-one; 3-(4-fluorophenyl)-4-oxo-2-(2,3,4-trifluorophenoxy)-3,4-dihydrothieno[3,2-d]pyrimidine-7-carbonitrile; 3-(4-fluorophenyl)-7-methyl-2-(2,3,4-trifluorophenoxy)thieno[3,2-d]pyrimidin-4(3H)-one; 3-(4-fluorophenyl)-7-methyl-2-(2,3,6-trifluorophenoxy)thieno[3,2-d]pyrimidin-4(3H)-one; 3-(4-fluorophenyl)-7-methyl-2-(2-methylphenoxy)thieno[3,2-d]pyrimidin-4(3H)-one; 4-{[1-(4-chlorophenyl)-9-methyl-6-oxo-6,9-dihydro-1H-purin-2-yl]oxy}-2,3-difluorobenzonitrile; 5-(2,3-difluorophenoxy)-6-(4-fluorophenyl)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one; 5-(4-chloro-2-fluorophenoxy)-6-(4-fluorophenyl)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one; 5-(9-Methyl-6-oxo-2-(3,4,5-trifluorophenoxy)-6H-purin-1(9H)-yl)picolinonitrile; 5-[2-chloro-3-(trifluoromethyl)phenoxy]-6-(4-fluorophenyl)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one; 6-(4-fluorophenyl)-5-(2,3,4-trifluorophenoxy)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one; 6-(4-fluorophenyl)-5-(2,3,5-trifluorophenoxy)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one; 6-(4-fluorophenyl)-5-(2,4,5-trifluorophenoxy)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one; 6-(4-fluorophenyl)-5-(3-(trifluoromethyl)phenoxy)thiazolo[5,4-d]pyrimidin-7(6H)-one; 6-(4-fluorophenyl)-5-(3,4,5-trifluorophenoxy)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one; 6-(4-fluorophenyl)-5-[2-fluoro-3-(trifluoromethyl)phenoxy][1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one; 6-(4-fluorophenyl)-5-[3-fluoro-5-(trifluoromethyl)phenoxy][1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one; 9-ethyl-1-(4-fluorophenyl)-2-(2,3,4-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 9-ethyl-1-(4-fluorophenyl)-2-(2,3,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; 9-ethyl-1-(4-fluorophenyl)-2-(2,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one; or 9-ethyl-1-(4-fluorophenyl)-2-(2,4,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one. 16.-17. (canceled) 18. A pharmaceutical composition, comprising at least one compound or salt or hydrate thereof according to claim 1 in combination with a physiologically acceptable carrier or excipient. 19.-32. (canceled) 33. A method for treating a condition responsive to capsaicin receptor modulation in a patient, comprising administering to the patient a therapeutically effective amount of at least one compound or salt or hydrate thereof according to claim 1, and thereby alleviating the condition in the patient. 34.-35. (canceled) 36. A method for treating pain in a patient, comprising administering to a patient suffering from pain a therapeutically effective amount of at least one compound or salt or hydrate thereof according to claim 1, and thereby alleviating pain in the patient. 37. A method according to claim 36, wherein the compound or salt or hydrate thereof is present in the blood of the patient at a concentration of 5 micromolar or less. 38. (canceled) 39. A method according to claim 36, wherein the patient is suffering from neuropathic pain. 40. (canceled) 41. A method according to claim 36, wherein the patient is a human. 42. A method for treating itch in a patient, comprising administering to a patient a therapeutically effective amount of a compound or salt or hydrate thereof according to claim 1, and thereby alleviating itch in the patient. 43. A method for treating cough or hiccup in a patient, comprising administering to a patient a therapeutically effective amount of a compound or salt or hydrate thereof according to claim 1, and thereby alleviating cough or hiccup in the patient. 44. A method for treating symptoms of menopause in a patient, comprising administering to a patient a therapeutically effective amount of a compound or salt or hydrate thereof according to claim 1, and thereby alleviating symptoms of menopause in the patient. 45. A method for treating urinary incontinence or overactive bladder in a patient, comprising administering to a patient a therapeutically effective amount of a compound or salt or hydrate thereof according to claim 1, and thereby alleviating urinary incontinence or overactive bladder in the patient. 46.-49. (canceled) 50. A packaged pharmaceutical preparation, comprising: (a) a pharmaceutical composition according to claim 18 in a container; and (b) instructions for using the composition. 51.-55. (canceled) 56. A method for treating pain in a patient, comprising administering to a patient suffering from pain a therapeutically effective amount of a combination of (i) at least one compound or salt or hydrate thereof according to claim 1, and (ii) ibuprofen, and thereby alleviating pain in the patient.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Pain perception, or nociception, is mediated by the peripheral terminals of a group of specialized sensory neurons, termed “nociceptors.” A wide variety of physical and chemical stimuli induce activation of such neurons in mammals, leading to recognition of a potentially harmful stimulus. Inappropriate or excessive activation of nociceptors, however, can result in debilitating acute or chronic pain. Neuropathic pain involves pain signal transmission in the absence of stimulus, and typically results from damage to the nervous system. In most instances, such pain is thought to occur because of sensitization in the peripheral and central nervous systems following initial damage to the peripheral system (e.g., via direct injury or systemic disease). Neuropathic pain is typically burning, shooting and unrelenting in its intensity and can sometimes be more debilitating that the initial injury or disease process that induced it. Existing treatments for neuropathic pain are largely ineffective. Opiates, such as morphine, are potent analgesics, but their usefulness is limited because of adverse side effects, such as physical addictiveness and withdrawal properties, as well as respiratory depression, mood changes, and decreased intestinal motility with concomitant constipation, nausea, vomiting, and alterations in the endocrine and autonomic nervous systems. In addition, neuropathic pain is frequently non-responsive or only partially responsive to conventional opioid analgesic regimens. Treatments employing the N-methyl-D-aspartate antagonist ketamine or the alpha(2)-adrenergic agonist clonidine can reduce acute or chronic pain, and permit a reduction in opioid consumption, but these agents are often poorly tolerated due to side effects. Topical treatment with capsaicin has been used to treat chronic and acute pain, including neuropathic pain. Capsaicin is a pungent substance derived from the plants of the Solanaceae family (which includes hot chili peppers) and appears to act selectively on the small diameter afferent nerve fibers (A-delta and C fibers) that are believed to mediate pain. The response to capsaicin is characterized by persistent activation of nociceptors in peripheral tissues, followed by eventual desensitization of peripheral nociceptors to one or more stimuli. From studies in animals, capsaicin appears to trigger C fiber membrane depolarization by opening cation selective channels for calcium and sodium. Similar responses are also evoked by structural analogues of capsaicin that share a common vanilloid moiety. One such analogue is resiniferatoxin (RTX), a natural product of Euphorbia plants. The term vanilloid receptor (VR) was coined to describe the neuronal membrane recognition site for capsaicin and such related irritant compounds. The capsaicin response is competitively inhibited (and thereby antagonized) by another capsaicin analog, capsazepine, and is also inhibited by the non-selective cation channel blocker ruthenium red, which binds to VR with no more than moderate affinity (typically with a K; value of no lower than 140 μM). Rat and human vanilloid receptors have been cloned from dorsal root ganglion cells. The first type of vanilloid receptor to be identified is known as vanilloid receptor type 1 (VR1), and the terms “VR1” and “capsaicin receptor” are used interchangeably herein to refer to rat and/or human receptors of this type, as well as mammalian homologues. The role of VR1 in pain sensation has been confirmed using mice lacking this receptor, which exhibit no vanilloid-evoked pain behavior and impaired responses to heat and inflammation. VR1 is a nonselective cation channel with a threshold for opening that is lowered in response to elevated temperatures, low pH, and capsaicin receptor agonists. Opening of the capsaicin receptor channel is generally followed by the release of inflammatory peptides from neurons expressing the receptor and other nearby neurons, increasing the pain response. After initial activation by capsaicin, the capsaicin receptor undergoes a rapid desensitization via phosphorylation by cAMP-dependent protein kinase. Because of their ability to desensitize nociceptors in peripheral tissues, VR1 agonist vanilloid compounds have been used as topical anesthetics. However, agonist application may itself cause burning pain, which limits this therapeutic use. Recently, it has been reported that VR1 antagonists, including certain nonvanilloid compounds, are also useful for the treatment of pain (see, e.g., PCT International Application Publication Numbers WO 02/08221, WO 03/062209, WO 04/054582, WO 04/055003, WO 04/055004, WO 04/056774, WO 05/007646, WO 05/007648, WO 05/007652, WO 05/009977, WO 05/009980, WO 05/009982, WO 05/049601, WO 05/049613, WO 06/122200 and WO 06/120481). Thus, compounds that interact with VR1, but do not elicit the initial painful sensation of VR1 agonist vanilloid compounds, are desirable for the treatment of chronic and acute pain, including neuropathic pain, as well as other conditions that are responsive to capsaicin receptor modulation. The present invention fulfills this need, and provides further related advantages.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention provides 2-phenoxy pyrimidinone analogues of Formula A: as well as pharmaceutically acceptable salts, solvates (e.g., hydrates) and esters of such compounds. Within Formula A: represents a fused 5- or 6-membered heteroaryl that contains 1, 2 or 3 heteroatoms in the ring, said heteroatoms being independently chosen from O, N and S, with the remaining ring atoms being carbon, wherein the fused heteroaryl is optionally substituted; preferably the fused heteroaryl is substituted with from 0 to 3, or from 0 to 2, substituents independently chosen from amino, hydroxy, C 1 -C 6 alkyl, C 1 -C 6 hydroxyalkyl, (C 3 -C 7 cycloalkyl)C 0 -C 2 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 alkoxy, C 2 -C 6 alkyl ether, C 1 -C 6 alkanoyloxy, C 1 -C 6 alkylsulfonylamino, C 1 -C 6 alkanonylamino, and mono- or di-(C 1 -C 6 alkyl)amino; Ar is phenyl or a 5- or 6-membered heteroaryl, each of which is optionally substituted, and each of which is preferably substituted with from 0 to 4 or from 0 to 3 substituents that are independently chosen from halogen, cyano, amino, nitro, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 haloalkyl, C 1 -C 6 hydroxyalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, (C 3 -C 7 cycloalkyl)C 0 -C 4 alkyl, and mono- or di-(C 1 -C 6 alkyl)amino; and R 3 represents from 0 to 4, or from 0 to 3, substituents, which substituents are preferably independently chosen from halogen, hydroxy, cyano, amino, nitro, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 haloalkyl, C 1 -C 6 hydroxyalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, (C 3 -C 7 cycloalkyl)C 0 -C 4 alkyl, mono- or di-(C 1 -C 6 alkyl)amino, and mono- or di-(C 1 -C 6 alkyl)aminosulfonyl. The present invention further provides 2-phenoxy pyrimidinone analogues of Formula I: as well as pharmaceutically acceptable salts, solvates (e.g., hydrates) and esters of such compounds. Within Formula I: and R 3 are as described for Formula A; X is N or CH that is optionally substituted with a substituent represented by R 1 ; and R 1 represents from 0 to 3 substituents; which substituents are preferably independently chosen from halogen, cyano, amino, nitro, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 haloalkyl, C 1 -C 6 hydroxyalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, (C 3 -C 7 cycloalkyl)C 0 -C 4 alkyl, and mono- or di-(C 1 -C 6 alkyl)amino. Within certain aspects, compounds of Formula A and Formula I are VR1 modulators and exhibit a K i of no greater than 1 micromolar, 500 nanomolar, 100 nanomolar, 50 nanomolar, 10 nanomolar or I nanomolar in a capsaicin receptor binding assay and/or have an EC 50 or IC 50 value of no greater than 1 micromolar, 500 nanomolar, 100 nanomolar, 50 nanomolar, 10 nanomolar or 1 nanomolar in an in vitro assay for determination of capsaicin receptor agonist or antagonist activity. In certain embodiments, such VR1 modulators are VR1 antagonists and exhibit no detectable agonist activity in an in vitro assay of capsaicin receptor activation (e.g., the assay provided in Example 6, herein) at a concentration equal to the IC 50 , 10 times the IC 50 or 100 times the IC 50 . Within certain aspects, compounds provided herein are labeled with a detectable marker (e.g., radiolabeled or fluorescein conjugated). The present invention further provides, within other aspects, pharmaceutical compositions comprising at least one 2-phenoxy pyrimidinone analogue in combination with a physiologically acceptable carrier or excipient. Within further aspects, methods are provided for reducing calcium conductance of a cellular capsaicin receptor, comprising contacting a cell (e.g., neuronal, such as cells of the central nervous system or peripheral ganglia, urothelial or lung) that expresses a capsaicin receptor with at least one VR1 modulator as described herein. Such contact may occur in vivo or in vitro and is generally performed using a concentration of VR1 modulator that is sufficient to alter the binding of vanilloid ligand to VR1 in vitro (using the assay provided in Example 5) and/or VR1-mediated signal transduction (using an assay provided in Example 6). Methods are further provided for inhibiting binding of vanilloid ligand to a capsaicin receptor. Within certain embodiments, the inhibition takes place in vitro. Such methods comprise contacting a capsaicin receptor with at least one VR1 modulator as described herein, under conditions and in an amount or concentration sufficient to detectably inhibit vanilloid ligand binding to the capsaicin receptor. Within other embodiments, the capsaicin receptor is in a patient. Such methods comprise contacting cells expressing a capsaicin receptor in a patient with at least one VR1 modulator as described herein in an amount or concentration that would be sufficient to detectably inhibit vanilloid ligand binding to cells expressing a cloned capsaicin receptor in vitro. The present invention further provides methods for treating a condition responsive to capsaicin receptor modulation in a patient, comprising administering to the patient a therapeutically effective amount of at least one VR1 modulator as described herein. Within other aspects, methods are provided for treating pain in a patient, comprising administering to a patient suffering from (or at risk for) pain a therapeutically effective amount of at least one VR1 modulator as described herein. Methods are further provided for treating itch, urinary incontinence, overactive bladder, menopause symptoms, cough and/or hiccup in a patient, comprising administering to a patient suffering from (or at risk for) one or more of the foregoing conditions a therapeutically effective amount of at least one VR1 modulator as described herein. Within other aspects, methods are provided for treating menopause symptoms in a patient, comprising administering to a patient suffering from (or at risk for) such symptoms a therapeutically effective amount of at least one VR1 modulator as described herein. The present invention further provides methods for promoting weight loss in an obese patient, comprising administering to an obese patient a therapeutically effective amount of at least one VR1 modulator as described herein. Methods are further provided for identifying an agent that binds to capsaicin receptor, comprising: (a) contacting capsaicin receptor with a labeled compound as described herein under conditions that permit binding of the compound to capsaicin receptor, thereby generating bound, labeled compound; (b) detecting a signal that corresponds to the amount of bound, labeled compound in the absence of test agent; (c) contacting the bound, labeled compound with a test agent; (d) detecting a signal that corresponds to the amount of bound labeled compound in the presence of test agent; and (e) detecting a decrease in signal detected in step (d), as compared to the signal detected in step (b). Within further aspects, the present invention provides methods for determining the presence or absence of capsaicin receptor in a sample, comprising: (a) contacting a sample with a compound as described herein under conditions that permit binding of the compound to capsaicin receptor; and (b) detecting a signal indicative of a level of the compound bound to capsaicin receptor. The present invention also provides packaged pharmaceutical preparations, comprising: (a) a pharmaceutical composition as described herein in a container; and (b) instructions for using the composition to treat one or more conditions responsive to capsaicin receptor modulation, such as pain, itch, urinary incontinence, overactive bladder, menopause symptoms, cough, hiccup and/or obesity. In yet another aspect, the present invention provides methods for preparing the compounds disclosed herein, including the intermediates. These and other aspects of the invention will become apparent upon reference to the following detailed description. detailed-description description="Detailed Description" end="lead"?
|
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application 60/823,258, filed Aug. 23, 2006, which is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION This invention relates generally to 2-phenoxy pyrimidinone analogues that have useful pharmacological properties. The invention further relates to the use of such compounds for treating conditions related to capsaicin receptor activation, for identifying other agents that bind to capsaicin receptor, and as probes for the detection and localization of capsaicin receptors. BACKGROUND OF THE INVENTION Pain perception, or nociception, is mediated by the peripheral terminals of a group of specialized sensory neurons, termed “nociceptors.” A wide variety of physical and chemical stimuli induce activation of such neurons in mammals, leading to recognition of a potentially harmful stimulus. Inappropriate or excessive activation of nociceptors, however, can result in debilitating acute or chronic pain. Neuropathic pain involves pain signal transmission in the absence of stimulus, and typically results from damage to the nervous system. In most instances, such pain is thought to occur because of sensitization in the peripheral and central nervous systems following initial damage to the peripheral system (e.g., via direct injury or systemic disease). Neuropathic pain is typically burning, shooting and unrelenting in its intensity and can sometimes be more debilitating that the initial injury or disease process that induced it. Existing treatments for neuropathic pain are largely ineffective. Opiates, such as morphine, are potent analgesics, but their usefulness is limited because of adverse side effects, such as physical addictiveness and withdrawal properties, as well as respiratory depression, mood changes, and decreased intestinal motility with concomitant constipation, nausea, vomiting, and alterations in the endocrine and autonomic nervous systems. In addition, neuropathic pain is frequently non-responsive or only partially responsive to conventional opioid analgesic regimens. Treatments employing the N-methyl-D-aspartate antagonist ketamine or the alpha(2)-adrenergic agonist clonidine can reduce acute or chronic pain, and permit a reduction in opioid consumption, but these agents are often poorly tolerated due to side effects. Topical treatment with capsaicin has been used to treat chronic and acute pain, including neuropathic pain. Capsaicin is a pungent substance derived from the plants of the Solanaceae family (which includes hot chili peppers) and appears to act selectively on the small diameter afferent nerve fibers (A-delta and C fibers) that are believed to mediate pain. The response to capsaicin is characterized by persistent activation of nociceptors in peripheral tissues, followed by eventual desensitization of peripheral nociceptors to one or more stimuli. From studies in animals, capsaicin appears to trigger C fiber membrane depolarization by opening cation selective channels for calcium and sodium. Similar responses are also evoked by structural analogues of capsaicin that share a common vanilloid moiety. One such analogue is resiniferatoxin (RTX), a natural product of Euphorbia plants. The term vanilloid receptor (VR) was coined to describe the neuronal membrane recognition site for capsaicin and such related irritant compounds. The capsaicin response is competitively inhibited (and thereby antagonized) by another capsaicin analog, capsazepine, and is also inhibited by the non-selective cation channel blocker ruthenium red, which binds to VR with no more than moderate affinity (typically with a K; value of no lower than 140 μM). Rat and human vanilloid receptors have been cloned from dorsal root ganglion cells. The first type of vanilloid receptor to be identified is known as vanilloid receptor type 1 (VR1), and the terms “VR1” and “capsaicin receptor” are used interchangeably herein to refer to rat and/or human receptors of this type, as well as mammalian homologues. The role of VR1 in pain sensation has been confirmed using mice lacking this receptor, which exhibit no vanilloid-evoked pain behavior and impaired responses to heat and inflammation. VR1 is a nonselective cation channel with a threshold for opening that is lowered in response to elevated temperatures, low pH, and capsaicin receptor agonists. Opening of the capsaicin receptor channel is generally followed by the release of inflammatory peptides from neurons expressing the receptor and other nearby neurons, increasing the pain response. After initial activation by capsaicin, the capsaicin receptor undergoes a rapid desensitization via phosphorylation by cAMP-dependent protein kinase. Because of their ability to desensitize nociceptors in peripheral tissues, VR1 agonist vanilloid compounds have been used as topical anesthetics. However, agonist application may itself cause burning pain, which limits this therapeutic use. Recently, it has been reported that VR1 antagonists, including certain nonvanilloid compounds, are also useful for the treatment of pain (see, e.g., PCT International Application Publication Numbers WO 02/08221, WO 03/062209, WO 04/054582, WO 04/055003, WO 04/055004, WO 04/056774, WO 05/007646, WO 05/007648, WO 05/007652, WO 05/009977, WO 05/009980, WO 05/009982, WO 05/049601, WO 05/049613, WO 06/122200 and WO 06/120481). Thus, compounds that interact with VR1, but do not elicit the initial painful sensation of VR1 agonist vanilloid compounds, are desirable for the treatment of chronic and acute pain, including neuropathic pain, as well as other conditions that are responsive to capsaicin receptor modulation. The present invention fulfills this need, and provides further related advantages. SUMMARY OF THE INVENTION The present invention provides 2-phenoxy pyrimidinone analogues of Formula A: as well as pharmaceutically acceptable salts, solvates (e.g., hydrates) and esters of such compounds. Within Formula A: represents a fused 5- or 6-membered heteroaryl that contains 1, 2 or 3 heteroatoms in the ring, said heteroatoms being independently chosen from O, N and S, with the remaining ring atoms being carbon, wherein the fused heteroaryl is optionally substituted; preferably the fused heteroaryl is substituted with from 0 to 3, or from 0 to 2, substituents independently chosen from amino, hydroxy, C1-C6alkyl, C1-C6hydroxyalkyl, (C3-C7cycloalkyl)C0-C2alkyl, C1-C6haloalkyl, C1-C6alkoxy, C2-C6alkyl ether, C1-C6alkanoyloxy, C1-C6alkylsulfonylamino, C1-C6alkanonylamino, and mono- or di-(C1-C6alkyl)amino; Ar is phenyl or a 5- or 6-membered heteroaryl, each of which is optionally substituted, and each of which is preferably substituted with from 0 to 4 or from 0 to 3 substituents that are independently chosen from halogen, cyano, amino, nitro, C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, C1-C6haloalkyl, C1-C6hydroxyalkyl, C1-C6alkoxy, C1-C6haloalkoxy, (C3-C7cycloalkyl)C0-C4alkyl, and mono- or di-(C1-C6alkyl)amino; and R3 represents from 0 to 4, or from 0 to 3, substituents, which substituents are preferably independently chosen from halogen, hydroxy, cyano, amino, nitro, C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, C1-C6haloalkyl, C1-C6hydroxyalkyl, C1-C6alkoxy, C1-C6haloalkoxy, (C3-C7cycloalkyl)C0-C4alkyl, mono- or di-(C1-C6alkyl)amino, and mono- or di-(C1-C6alkyl)aminosulfonyl. The present invention further provides 2-phenoxy pyrimidinone analogues of Formula I: as well as pharmaceutically acceptable salts, solvates (e.g., hydrates) and esters of such compounds. Within Formula I: and R3 are as described for Formula A; X is N or CH that is optionally substituted with a substituent represented by R1; and R1 represents from 0 to 3 substituents; which substituents are preferably independently chosen from halogen, cyano, amino, nitro, C1-C6alkyl, C2-C6alkenyl, C2-C6alkynyl, C1-C6haloalkyl, C1-C6hydroxyalkyl, C1-C6alkoxy, C1-C6haloalkoxy, (C3-C7cycloalkyl)C0-C4alkyl, and mono- or di-(C1-C6alkyl)amino. Within certain aspects, compounds of Formula A and Formula I are VR1 modulators and exhibit a Ki of no greater than 1 micromolar, 500 nanomolar, 100 nanomolar, 50 nanomolar, 10 nanomolar or I nanomolar in a capsaicin receptor binding assay and/or have an EC50 or IC50 value of no greater than 1 micromolar, 500 nanomolar, 100 nanomolar, 50 nanomolar, 10 nanomolar or 1 nanomolar in an in vitro assay for determination of capsaicin receptor agonist or antagonist activity. In certain embodiments, such VR1 modulators are VR1 antagonists and exhibit no detectable agonist activity in an in vitro assay of capsaicin receptor activation (e.g., the assay provided in Example 6, herein) at a concentration equal to the IC50, 10 times the IC50 or 100 times the IC50. Within certain aspects, compounds provided herein are labeled with a detectable marker (e.g., radiolabeled or fluorescein conjugated). The present invention further provides, within other aspects, pharmaceutical compositions comprising at least one 2-phenoxy pyrimidinone analogue in combination with a physiologically acceptable carrier or excipient. Within further aspects, methods are provided for reducing calcium conductance of a cellular capsaicin receptor, comprising contacting a cell (e.g., neuronal, such as cells of the central nervous system or peripheral ganglia, urothelial or lung) that expresses a capsaicin receptor with at least one VR1 modulator as described herein. Such contact may occur in vivo or in vitro and is generally performed using a concentration of VR1 modulator that is sufficient to alter the binding of vanilloid ligand to VR1 in vitro (using the assay provided in Example 5) and/or VR1-mediated signal transduction (using an assay provided in Example 6). Methods are further provided for inhibiting binding of vanilloid ligand to a capsaicin receptor. Within certain embodiments, the inhibition takes place in vitro. Such methods comprise contacting a capsaicin receptor with at least one VR1 modulator as described herein, under conditions and in an amount or concentration sufficient to detectably inhibit vanilloid ligand binding to the capsaicin receptor. Within other embodiments, the capsaicin receptor is in a patient. Such methods comprise contacting cells expressing a capsaicin receptor in a patient with at least one VR1 modulator as described herein in an amount or concentration that would be sufficient to detectably inhibit vanilloid ligand binding to cells expressing a cloned capsaicin receptor in vitro. The present invention further provides methods for treating a condition responsive to capsaicin receptor modulation in a patient, comprising administering to the patient a therapeutically effective amount of at least one VR1 modulator as described herein. Within other aspects, methods are provided for treating pain in a patient, comprising administering to a patient suffering from (or at risk for) pain a therapeutically effective amount of at least one VR1 modulator as described herein. Methods are further provided for treating itch, urinary incontinence, overactive bladder, menopause symptoms, cough and/or hiccup in a patient, comprising administering to a patient suffering from (or at risk for) one or more of the foregoing conditions a therapeutically effective amount of at least one VR1 modulator as described herein. Within other aspects, methods are provided for treating menopause symptoms in a patient, comprising administering to a patient suffering from (or at risk for) such symptoms a therapeutically effective amount of at least one VR1 modulator as described herein. The present invention further provides methods for promoting weight loss in an obese patient, comprising administering to an obese patient a therapeutically effective amount of at least one VR1 modulator as described herein. Methods are further provided for identifying an agent that binds to capsaicin receptor, comprising: (a) contacting capsaicin receptor with a labeled compound as described herein under conditions that permit binding of the compound to capsaicin receptor, thereby generating bound, labeled compound; (b) detecting a signal that corresponds to the amount of bound, labeled compound in the absence of test agent; (c) contacting the bound, labeled compound with a test agent; (d) detecting a signal that corresponds to the amount of bound labeled compound in the presence of test agent; and (e) detecting a decrease in signal detected in step (d), as compared to the signal detected in step (b). Within further aspects, the present invention provides methods for determining the presence or absence of capsaicin receptor in a sample, comprising: (a) contacting a sample with a compound as described herein under conditions that permit binding of the compound to capsaicin receptor; and (b) detecting a signal indicative of a level of the compound bound to capsaicin receptor. The present invention also provides packaged pharmaceutical preparations, comprising: (a) a pharmaceutical composition as described herein in a container; and (b) instructions for using the composition to treat one or more conditions responsive to capsaicin receptor modulation, such as pain, itch, urinary incontinence, overactive bladder, menopause symptoms, cough, hiccup and/or obesity. In yet another aspect, the present invention provides methods for preparing the compounds disclosed herein, including the intermediates. These and other aspects of the invention will become apparent upon reference to the following detailed description. DETAILED DESCRIPTION As noted above, the present invention provides 2-phenoxy pyrimidinone analogues. Such compounds may be used in vitro or in vivo, to modulate capsaicin receptor activity in a variety of contexts. Terminology Compounds are generally described herein using standard nomenclature. For compounds having asymmetric centers, it should be understood that (unless otherwise specified) all of the optical isomers and mixtures thereof are encompassed. In addition, compounds with carbon-carbon double bonds may occur in Z- and E-forms, with all isomeric forms of the compounds being included in the present invention unless otherwise specified. Where a compound exists in various tautomeric forms, a recited compound is not limited to any one specific tautomer, but rather is intended to encompass all tautomeric forms. Certain compounds are described herein using a general formula that includes variables (e.g., R1, A). Unless otherwise specified, each variable within such a formula is defined independently of any other variable, and any variable that occurs more than one time in a formula is defined independently at each occurrence. The phrase “2-phenoxy pyrimidinone analogues,” as used herein, encompasses all compounds of Formula A, including those of Formula I, as well as compounds of other Formulas provided herein (including any enantiomers, racemates and stereoisomers) and pharmaceutically acceptable salts, solvates and esters of such compounds. A “pharmaceutically acceptable salt” of a compound recited herein is an acid or base salt that is suitable for use in contact with the tissues of human beings or animals without excessive toxicity or carcinogenicity, and preferably without irritation, allergic response, or other problem or complication. Such salts include mineral and organic acid salts of basic residues such as amines, as well as alkali or organic salts of acidic residues such as carboxylic acids. Specific pharmaceutically acceptable anions for use in salt formation include, but are not limited to, acetate, 2-acetoxybenzoate, ascorbate, benzoate, bicarbonate, bromide, calcium edetate, carbonate, chloride, citrate, dihydrochloride, diphosphate, ditartrate, edetate, estolate (ethylsuccinate), formate, fumarate, gluceptate, gluconate, glutamate, glycolate, glycollylarsanilate, hexylresorcinate, hydrabamine, hydrobromide, hydrochloride, hydroiodide, hydroxymaleate, hydroxynaphthoate, iodide, isethionate, lactate, lactobionate, malate, maleate, mandelate, methylbromide, methylnitrate, methylsulfate, mucate, napsylate, nitrate, pamoate, pantothenate, phenylacetate, phosphate, polygalacturonate, propionate, salicylate, stearate, subacetate, succinate, sulfamate, sulfanilate, sulfate, sulfonates including besylate (benzenesulfonate), camsylate (camphorsulfonate), edisylate (ethane-1,2-disulfonate), esylate (ethanesulfonate), 2-hydroxyethylsulfonate, mesylate (methanesulfonate), triflate (trifluoromethanesulfonate) and tosylate (p-toluenesulfonate), tannate, tartrate, teoclate and triethiodide. Similarly, pharmaceutically acceptable cations for use in salt formation include, but are not limited to ammonium, benzathine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine, procaine, and metals such as aluminum, calcium, lithium, magnesium, potassium, sodium and zinc. Those of ordinary skill in the art will recognize further pharmaceutically acceptable salts for the compounds provided herein. In general, a pharmaceutically acceptable acid or base salt can be synthesized from a parent compound that contains a basic or acidic moiety by any conventional chemical method. Briefly, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, the use of nonaqueous media, such as ether, ethyl acetate, ethanol, methanol, isopropanol or acetonitrile, is preferred. It will be apparent that each compound provided herein may, but need not, be formulated as a solvate (e.g., hydrate) or non-covalent complex. In addition, the various crystal forms and polymorphs are within the scope of the present invention. Also provided herein are prodrugs of the compounds of the recited Formulas. A “prodrug” is a compound that may not fully satisfy the structural requirements of the compounds provided herein, but is modified in vivo, following administration to a patient, to produce a compound a formula provided herein. For example, a prodrug may be an acylated derivative of a compound as provided herein. Prodrugs include compounds wherein hydroxy, amine or sulfhydryl groups are bonded to any group that, when administered to a mammalian subject, cleaves to form a free hydroxy, amino, or sulfhydryl group, respectively. Examples of prodrugs include, but are not limited to, acetate, formate and benzoate derivatives of alcohol and amine functional groups within the compounds provided herein. Prodrugs of the compounds provided herein may be prepared by modifying functional groups present in the compounds in such a way that the modifications are cleaved in vivo to yield the parent compounds. As used herein, the term “alkyl” refers to a straight or branched chain saturated aliphatic hydrocarbon. Alkyl groups include groups having from 1 to 8 carbon atoms (C1-C8alkyl), from 1 to 6 carbon atoms (C1-C6alkyl) and from 1 to 4 carbon atoms (C1-C4alkyl), such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, 2-pentyl, isopentyl, neopentyl, hexyl, 2-hexyl, 3-hexyl and 3-methylpentyl. “C0-Cnalkyl” refers to a single covalent bond (C0) or an alkyl group having from 1 to n carbon atoms; for example “C0-C4alkyl” refers to a single covalent bond or a C1-C4alkyl group. In some instances, a substituent of an alkyl group is specifically indicated. For example, “hydroxyalkyl” refers to an alkyl group substituted with at least one hydroxy substituent. “Alkylene” refers to a divalent alkyl group, as defined above. C1-C2alkylene is methylene or ethylene; C0-C4alkylene is a single covalent bond or an alkylene group having 1, 2, 3 or carbon atoms; C0-C2alkylene is a single covalent bond or an alkylene group having 1 or 2 carbon atoms. “Alkenyl” refers to straight or branched chain alkene groups, which comprise at least one unsaturated carbon-carbon double bond. Alkenyl groups include C2-C8alkenyl, C2-C6alkenyl and C2-C4alkenyl groups, which have from 2 to 8, 2 to 6 or 2 to 4 carbon atoms, respectively, such as ethenyl, allyl or isopropenyl. “Alkynyl” refers to straight or branched chain alkyne groups, which have one or more unsaturated carbon-carbon bonds, at least one of which is a triple bond. Alkynyl groups include C2-C8alkynyl, C2-C6alkynyl and C2-C4alkynyl groups, which have from 2 to 8, 2 to 6 or 2 to 4 carbon atoms, respectively. A “cycloalkyl” is a group that comprises one or more saturated and/or partially saturated rings in which all ring members are carbon, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, adamantyl, and partially saturated variants of the foregoing, such as cyclohexenyl. Cycloalkyl groups do not comprise an aromatic ring or a heterocyclic ring. Certain cycloalkyl groups are C3-C7cycloalkyl, in which the cycloalkyl group contains a single ring having from 3 to 7 ring members, all of which are carbon. A “(C3-C8cycloalkyl)C0-C4alkyl” is a C3-C8cycloalkyl group linked via a single covalent bond or a C1-C4alkylene group. By “alkoxy,” as used herein, is meant an alkyl group as described above attached via an oxygen bridge. Alkoxy groups include C1-C6alkoxy and C1-C4alkoxy groups, which have from 1 to 6 or from 1 to 4 carbon atoms, respectively. Methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, 2-pentoxy, 3-pentoxy, isopentoxy, neopentoxy, hexoxy, 2-hexoxy, 3-hexoxy, and 3-methylpentoxy are representative alkoxy groups. Similarly, “alkylthio” refers to an alkyl group as described above attached via a sulfur bridge. “Alkyl ether” refers to a linear or branched ether substituent (i.e., an alkyl group that is substituted with an alkoxy group). Alkyl ether groups include C2-C8alkyl ether, C2-C6alkyl ether and C2-C4alkyl ether groups, which have 2 to 8, 6 or 4 carbon atoms, respectively. A C2alkyl ether has the structure —CH2H3. The term “alkanoyl” refers to an acyl group (e.g., —(C═O)alkyl), in which carbon atoms are in a linear or branched alkyl arrangement and where attachment is through the carbon of the keto group. Alkanoyl groups have the indicated number of carbon atoms, with the carbon of the keto group being included in the numbered carbon atoms. For example a C2alkanoyl group is an acetyl group having the formula —(C═O)CH3; “C1alkanoyl” refers to —(C═O)H. “C1-C6alkanoyl groups” contain from 1 to 6 carbon atoms. The term “alkanoyloxy” as used herein refers to an alkanoyl group attached through an oxygen linker (i.e., a group having the general structure C(═O)alkyl). Alkanoyloxy groups include, for example, C1-C6alkanoyloxy groups, which have from one to six carbon atoms. “Alkanoylamino,” as used herein, refers to an alkanoyl group attached through an amino linker (i.e., a group having the general structure —N(R)—C(═O)alkyl), in which R is hydrogen or C1-C6alkyl). Alkanoylamino groups include, for example, C1-C6alkanoylamino groups, which have from 1 to 6 carbon atoms in the “alkyl” portion (i.e., the carbon of the keto bridge is not included in the indicated number of carbon atoms). “Alkylsulfonyl” refers to groups of the formula —(SO2)-alkyl, in which the sulfur atom is the point of attachment. Alkylsulfonyl groups include C1-C6alkylsulfonyl and C1-C4alkylsulfonyl groups, which have from 1 to 6 or from 1 to 4 carbon atoms, respectively. Methylsulfonyl is one representative alkylsulfonyl group. “Alkylsulfonylamino” refers to an alkylsulfonyl group attached through an amino linker (i.e., a group having the general structure —N(R)—(SO2)-alkyl), in which R is hydrogen or C1-C6alkyl). Alkylsulfonylamino groups include, for example, C1-C6alkylsulfonylamino groups, which have from 1 to 6 carbon atoms. “Aminosulfonyl” refers to groups of the formula —(SO2)—NH2, in which the sulfur atom is the point of attachment. The term “mono- or di-(C1-C6alkyl)aminosulfonyl” refers to groups that satisfy the formula —(SO2)—NR2, in which the sulfur atom is the point of attachment, and in which one R is C1-C6alkyl and the other R is hydrogen or an independently chosen C1-C6alkyl. “Alkylamino” refers to a secondary or tertiary amine that has the general structure —NH-alkyl or —N(alkyl)(alkyl), wherein each alkyl is selected independently from alkyl, cycloalkyl and (cycloalkyl)alkyl groups. Such groups include, for example, mono- and di-(C1-C6alkyl)amino groups, in which each C1-C6alkyl may be the same or different. “Alkylaminoalkyl” refers to an alkylamino group linked via an alkylene group (i.e., a group having the general structure -alkylene-NH-alkyl or -alkylene-N(alkyl)(alkyl)) in which each alkyl is selected independently from alkyl, cycloalkyl and (cycloalkyl)alkyl groups. Alkylaminoalkyl groups include, for example, mono- and di-(C1-C8alkyl)aminoC1-C8alkyl, mono- and di-(C1-C6alkyl)aminoC1-C6alkyl and mono- and di-(C1-C6alkyl)aminoC1-C4alkyl. “Mono- or di-(C1-C6alkyl)aminoC0-C6alkyl” refers to a mono- or di-(C1-C6alkyl)amino group linked via a single covalent bond or a C1-C6alkylene group. The following are representative alkylaminoalkyl groups: It will be apparent that the definition of “alkyl” as used in the terms “alkylamino” and “alkylaminoalkyl” differs from the definition of “alkyl” used for all other alkyl-containing groups, in the inclusion of cycloalkyl and (cycloalkyl)alkyl groups (e.g., (C3-C7cycloalkyl)C0-C4alkyl). The term “aminocarbonyl” refers to an amide group (i.e., —(C═O)NH2). The term “mono- or di-(C1-C6alkyl)aminocarbonyl” refers to groups of the formula —(C═O)—N(R)2, in which the carbonyl is the point of attachment, one R is C1-C6alkyl and the other R is hydrogen or an independently chosen C1-C6alkyl. The term “halogen” refers to fluorine, chlorine, bromine or iodine. A “haloalkyl” is an alkyl group that is substituted with 1 or more independently chosen halogens (e.g., “C1-C6haloalkyl” groups have from 1 to 6 carbon atoms). Examples of haloalkyl groups include, but are not limited to, mono-, di- or tri-fluoromethyl; mono-, di- or tri-chloromethyl; mono-, di-, tri-, tetra- or penta-fluoroethyl; mono-, di-, tri-, tetra- or penta-chloroethyl; and 1,2,2,2-tetrafluoro-1-trifluoromethyl-ethyl. Typical haloalkyl groups are trifluoromethyl and difluoromethyl. The term “haloalkoxy” refers to a haloalkyl group as defined above that is linked via an oxygen bridge. A dash (“-”) that is not between two letters or symbols is used to indicate a point of attachment for a substituent. For example, —CONH2 is attached through the carbon atom. A “heteroaryl” is an aromatic group in which at least one aromatic ring comprises at least one heteroatom selected from N, O and S. Heteroaryls include, for example, 5- and 6-membered heteroaryls such as imidazole, furan, furazan, isothiazole, isoxazole, oxadiazole, oxazole, pyrazine, pyrazole, pyridazine, pyridine, pyrimidine, tetrazole, thiazole and thiophene. A “substituent,” as used herein, refers to a molecular moiety that is covalently bonded to an atom within a molecule of interest. For example, a ring substituent may be a moiety such as a halogen, alkyl group, haloalkyl group or other group that is covalently bonded to an atom (preferably a carbon or nitrogen atom) that is a ring member. Substituents of aromatic groups are generally covalently bonded to a ring carbon atom. The term “substitution” refers to replacing a hydrogen atom in a molecular structure with a substituent, such that the valence on the designated atom is not exceeded, and such that a chemically stable compound (I.e., a compound that can be isolated, characterized, and tested for biological activity) results from the substitution. Groups that are “optionally substituted” are unsubstituted or are substituted by other than hydrogen at one or more available positions, typically 1, 2, 3, 4 or 5 positions, by one or more suitable groups (which may be the same or different). Optional substitution is also indicated by the phrase “substituted with from 0 to X substituents,” where X is the maximum number of possible substituents. Certain optionally substituted groups are substituted with from 0 to 2, 3 or 4 independently selected substituents (i.e., are unsubstituted or substituted with up to the recited maximum number of substituents). Other optionally substituted groups are substituted with at least one substituent (e.g., substituted with from 1 to 2, 3 or 4 independently selected substituents). The terms “VR1” and “capsaicin receptor” are used interchangeably herein to refer to a type 1 vanilloid receptor. Unless otherwise specified, these terms encompass both rat and human VR1 receptors (e.g., GenBank Accession Numbers AF327067, AJ277028 and NM—018727; sequences of certain human VR1 cDNAs and the encoded amino acid sequences are provided in U.S. Pat. No. 6,482,611), as well as homologues thereof found in other species. A “VR1 modulator,” also referred to herein as a “modulator,” is a compound that modulates VR1 activation and/or VR1-mediated signal transduction. VR1 modulators specifically provided herein are compounds of Formula A, and pharmaceutically acceptable salts, hydrates and esters thereof. Certain preferred VR1 modulators are not vanilloids. A VR1 modulator may be a VR1 agonist or antagonist. Certain modulators bind to VR1 with a Ki that is less than 1 micromolar, preferably less than 500 nanomolar, 100 nanomolar, 10 nanomolar or 1 nanomolar. A representative assay for determining Ki at VR1 is provided in Example 5, herein. A modulator is considered an “antagonist” if it detectably inhibits vanilloid ligand binding to VR1 and/or VR1-mediated signal transduction (using, for example, the representative assay provided in Example 6); in general, such an antagonist inhibits VR1 activation with a IC50 value of less than 1 micromolar, preferably less than 500 nanomolar, and more preferably less than 100 nanomolar, 10 nanomolar or 1 nanomolar within the assay provided in Example 6. VR1 antagonists include neutral antagonists and inverse agonists. An “inverse agonist” of VR1 is a compound that reduces the activity of VR1 below its basal activity level in the absence of added vanilloid ligand. Inverse agonists of VR1 may also inhibit the activity of vanilloid ligand at VR1 and/or binding of vanilloid ligand to VR1. The basal activity of VR1, as well as the reduction in VR1 activity due to the presence of VR1 antagonist, may be determined from a calcium mobilization assay, such as the assay of Example 6. A “neutral antagonist” of VR1 is a compound that inhibits the activity of vanilloid ligand at VR1, but does not significantly change the basal activity of the receptor (i.e., within a calcium mobilization assay as described in Example 6 performed in the absence of vanilloid ligand, VR1 activity is reduced by no more than 10%, preferably by no more than 5%, and more preferably by no more than 2%; most preferably, there is no detectable reduction in activity). Neutral antagonists of VR1 may inhibit the binding of vanilloid ligand to VR1. As used herein a “capsaicin receptor agonist” or “VR1 agonist” is a compound that elevates the activity of the receptor above the basal activity level of the receptor (i.e., enhances VR1 activation and/or VR1-mediated signal transduction). Capsaicin receptor agonist activity may be identified using the representative assay provided in Example 6. In general, such an agonist has an EC50 value of less than 1 micromolar, preferably less than 500 nanomolar, and more preferably less than 100 nanomolar or 10 nanomolar within the assay provided in Example 6. A “vanilloid” is any compound that comprises a phenyl ring with two oxygen atoms bound to adjacent ring carbon atoms (one of which carbon atom is located para to the point of attachment of a third moiety that is bound to the phenyl ring). Capsaicin is a representative vanilloid. A “vanilloid ligand” is a vanilloid that binds to VR1 with a Ki (determined as described herein) that is no greater than 10 μM. Vanilloid ligand agonists include capsaicin, olvanil, N-arachidonoyl-dopamine and resiniferatoxin (RTX). Vanilloid ligand antagonists include capsazepine and iodo-resiniferatoxin. A “therapeutically effective amount” (or dose) is an amount that, upon administration to a patient, results in a discernible patient benefit (e.g., provides detectable relief from at least one condition being treated). Such relief may be detected using any appropriate criteria, including alleviation of one or more symptoms such as pain. A therapeutically effective amount or dose generally results in a concentration of compound in a body fluid (such as blood, plasma, serum, CSF, synovial fluid, lymph, cellular interstitial fluid, tears or urine) that is sufficient to alter the binding of vanilloid ligand to VR1 in vitro (using the assay provided in Example 5) and/or VR1-mediated signal transduction (using an assay provided in Example 6). It will be apparent that the discernible patient benefit may be apparent after administration of a single dose, or may become apparent following repeated administration of the therapeutically effective dose according to a predetermined regimen, depending upon the indication for which the compound is administered. By “statistically significant,” as used herein, is meant results varying from control at the p<0.1 level of significance as measured using a standard parametric assay of statistical significance such as a student's T test. A “patient” is any individual treated with a compound provided herein. Patients include humans, as well as other animals such as companion animals (e.g., dogs and cats) and livestock. Patients may be experiencing one or more symptoms of a condition responsive to capsaicin receptor modulation (e.g., pain, exposure to vanilloid ligand, itch, urinary incontinence, overactive bladder, menopause symptoms, respiratory disorders, cough and/or hiccup), or may be free of such symptom(s) (i.e., treatment may be prophylactic in a patient considered at risk for the development of such symptoms). 2-Phenoxy Pyrimidinone Analogues As noted above, the present invention provides 2-phenoxy pyrimidinone analogues of Formula A. Within certain aspects, such compounds are VR1 modulators that may be used in a variety of contexts, including in the treatment of pain (e.g., neuropathic or peripheral nerve-mediated pain); exposure to capsaicin; exposure to acid, heat, light, tear gas, air pollutants (such as, for example, tobacco smoke), infectious agents (including viruses, bacteria and yeast), pepper spray or related agents; respiratory conditions such as asthma or chronic obstructive pulmonary disease; itch; urinary incontinence or overactive bladder; menopause symptoms; cough or hiccup; and/or obesity. Such compounds may also be used within in vitro assays (e.g., assays for receptor activity), as probes for detection and localization of VR1 and as standards in ligand binding and VR1-mediated signal transduction assays. It has been found, within the context of the present invention, that the 2-phenoxy pyrimidinone analogues provided herein exhibit an unexpectedly high VR1-modulating activity due, at least in part, to the phenoxy moiety of Formula A and Formula I. As noted above, represents a fused, optionally substituted 5- or 6-membered heteroaryl in which 1, 2 or 3 ring members are heteroatoms independently chosen from O, N and S, and the remaining ring members are carbon. Within certain embodiments, is substituted with from 0 to 2 substituents independently chosen from C1-C6alkyl, (C3-C7cycloalkyl)C0-C2alkyl and C1-C6haloalkyl. Within further embodiments, is substituted with from 0 to 2 substituents independently chosen from C1-C4alkyl, (C3-C5cycloalkyl)C0-C2alkyl and C1-C4haloalkyl. Within certain embodiments, is a 5-membered heteroaryl that is substituted with from 0 to 2 substituents independently chosen from C1-C4alkyl, (C3-C5cycloalkyl)C0-C2alkyl and C1-C4haloalkyl. In other embodiments, is a 5-membered heteroaryl represented by any of the formulae: in which R14 is hydrogen, C1-C4alkyl, (C3-C5cycloalkyl)C0-C2alkyl, C1-C4haloalkyl, C1-C4hydroxyalkyl, C1-C4alkoxy, C1-C4alkanoylamino or C1-C4alkylsulfonylamino. Representative such groups include, for example, in which R2 is, for example, hydrogen, cyano, aryl, heteroaryl, halogen, C1-C4alkyl, C1-C4haloalkyl or C3-C5cycloalkyl. Within certain embodiments, It will be apparent that the orientation of such moieties is intended to be retained as shown (e.g., if then the bicyclic core Within other embodiments, is a 6-membered heteroaryl that is substituted with from 0 to 3 substituents independently chosen from hydroxy, C1-C6alkyl, (C3-C7cycloalkyl)C0-C2alkyl, C1-C6haloalkyl, C1-C6hydroxyalkyl, C1-C6alkoxy, mono-(C1-C6alkyl)amino, C1-C6alkanoylamino or C1-C6alkylsulfonylamino. Representative such groups include, for example, wherein R4 represents from 0 to 3, preferably from 1 to 3, substituents independently chosen from hydroxy, C1-C4alkyl, (C3-C5cycloalkyl)C0-C2alkyl, C1-C4haloalkyl, C1-C4hydroxyalkyl, C1-C4alkoxy, mono-(C1-C4alkyl)amino, C1-C4alkanoylamino or C1-C4alkylsulfonylamino. The variable R1, within certain embodiments, represents from 0 to 3, preferably from 1 to 3, substituents independently chosen from halogen, cyano, C1-C4alkyl and C1-C4haloalkyl. For example, R1 represents exactly one substituent (e.g., at the para position of the ring Ar) within certain such compounds. Within other such compounds, at least one substituent represented by R1 is a halogen or CN; such substituent is located at the para position of a 6-membered Ar moiety within certain such compounds. It will be apparent that, within Formula I, the para position refers to the position para to the point of attachment of the Ar moiety to the pyrimidinone core; that is, the 4-position of the phenyl ring that results when X is CH, and the 6-position of the pyridin-3-yl ring that results when X is N. Within certain embodiments, R3 represents from 1 to 3 substituents independently chosen from halogen, cyano, C1-C4alkyl, C1-C4haloalkyl and C1-C4alkoxy. In certain embodiments, compounds of Formula I further satisfy one of Formulas II-VII: in which R2 is hydrogen, C1-C4alkyl, C1-C4haloalkyl or C3-C5cycloalkyl; R3 represents from 1 to 3 substituents independently chosen from halogen, cyano, C1-C4alkyl, C1-C4haloalkyl and C1-C4alkoxy; R14 is hydrogen, C1-C4alkyl, (C3-C5cycloalkyl)C0-C2alkyl, C1-C4haloalkyl, C1-C4hydroxyalkyl, C1-C4alkoxy, C1-C4alkanoylamino or C1-C4alkylsulfonylamino; and R5 is halogen or CN. In certain embodiments of Formulas II-VII, R′4 is H (i.e., such compounds further satisfy one of Formulas II1-VIIa: in which variables are as described for Formulas II-VII. Within further embodiments, compounds of Formula I further satisfy Formula VIII or IX: in which R3 represents from 1 to 3 substituents independently chosen from halogen, cyano, C1-C4alkyl, C1-C4haloalkyl and C1-C4alkoxy; R4 represents from 0 to 2 substituents independently chosen from hydroxy, C1-C4alkyl, (C3-C5cycloalkyl)C0-C2alkyl, C1-C4haloalkyl, C1-C4hydroxyalkyl, C1-C4alkoxy, mono-(C1-C4alkyl)amino, C1-C4alkanoylamino or C1-C4alkylsulfonylamino; and R5 is halogen or CN. Representative 2-phenoxy pyrimidinone analogues and intermediates provided herein include, but are not limited to, those specifically described in Examples 1-3. It will be apparent that the specific compounds recited herein are representative only, and are not intended to limit the scope of the present invention. Further, as noted above, all compounds of the present invention may be present as a free acid or base, or as a pharmaceutically acceptable salt. In addition, other forms such as hydrates and prodrugs of such compounds are specifically contemplated by the present invention. Within certain aspects of the present invention, 2-phenoxy pyrimidinone analogues provided herein detectably alter (modulate) VR1 activity, as determined using an in vitro VR1 functional assay such as a calcium mobilization assay. As an initial screen for such activity, a VR1 ligand binding assay may be used. References herein to a “VR1 ligand binding assay” are intended to refer to a standard in vitro receptor binding assay such as that provided in Example 5, and a “calcium mobilization assay” (also referred to herein as a “signal transduction assay”) may be performed as described in Example 6. Briefly, to assess binding to VR1, a competition assay may be performed in which a VR1 preparation is incubated with labeled (e.g., 125I or 3H) compound that binds to VR1 (e.g., a capsaicin receptor agonist such as RTX) and unlabeled test compound. Within the assays provided herein, the VR1 used is preferably mammalian VR1, more preferably human or rat VR1. The receptor may be recombinantly expressed or naturally expressed. The VR1 preparation may be, for example, a membrane preparation from HEK293 or CHO cells that recombinantly express human VR1. Incubation with a compound that detectably modulates vanilloid ligand binding to VR1 results in a decrease or increase in the amount of label bound to the VR1 preparation, relative to the amount of label bound in the absence of the compound. This decrease or increase may be used to determine the Ki at VR1 as described herein. In general, compounds that decrease the amount of label bound to the VR1 preparation within such an assay are preferred. Certain VR1 modulators provided herein detectably modulate VR1 activity at nanomolar (i.e., submicromolar) concentrations, at subnanomolar concentrations, or at concentrations below 100 picomolar, 20 picomolar, 10 picomolar or 5 picomolar. As noted above, compounds that are VR1 antagonists are preferred within certain embodiments. IC50 values for such compounds may be determined using a standard in vitro VR1-mediated calcium mobilization assay, as provided in Example 6. Briefly, cells expressing capsaicin receptor are contacted with a compound of interest and with an indicator of intracellular calcium concentration (e.g., a membrane permeable calcium sensitivity dye such as Fluo-3 or Fura-2 (Molecular Probes, Eugene, Oreg.), each of which produce a fluorescent signal when bound to Ca++). Such contact is preferably carried out by one or more incubations of the cells in buffer or culture medium comprising either or both of the compound and the indicator in solution. Contact is maintained for an amount of time sufficient to allow the dye to enter the cells (e.g., 1-2 hours). Cells are washed or filtered to remove excess dye and are then contacted with a vanilloid receptor agonist (e.g., capsaicin, RTX or olvanil), typically at a concentration equal to the EC50 concentration, and a fluorescence response is measured. When agonist-contacted cells are contacted with a compound that is a VR1 antagonist the fluorescence response is generally reduced by at least 20%, preferably at least 50% and more preferably at least 80%, as compared to cells that are contacted with the agonist in the absence of test compound. The IC50 for VR1 antagonists provided herein is preferably less than 1 micromolar, less than 100 nM, less than 10 nM or less than 1 nM. In certain embodiments, VR1 antagonists provided herein exhibit no detectable agonist activity an in vitro assay of capsaicin receptor agonism at a concentration of compound equal to the IC50. Certain such antagonists exhibit no detectable agonist activity an in vitro assay of capsaicin receptor agonism at a concentration of compound that is 100-fold higher than the IC50. In other embodiments, compounds that are capsaicin receptor agonists are preferred. Capsaicin receptor agonist activity may generally be determined as described in Example 6. When cells are contacted with 1 micromolar of a compound that is a VR1 agonist, the fluorescence response is generally increased by an amount that is at least 30% of the increase observed when cells are contacted with 100 nM capsaicin. The EC50 for VR1 agonists provided herein is preferably less than 1 micromolar, less than 100 nM or less than 10 mM. VR1 modulating activity may also, or alternatively, be assessed using a cultured dorsal root ganglion assay as provided in Example 7 and/or an in vivo pain relief assay as provided in Example 8. VR1 modulators provided herein preferably have a statistically significant specific effect on VR1 activity within one or more functional assays provided herein. Within certain embodiments, VR1 modulators provided herein do not substantially modulate ligand binding to other cell surface receptors, such as EGF receptor tyrosine kinase or the nicotinic acetylcholine receptor. In other words, such modulators do not substantially inhibit activity of a cell surface receptor such as the human epidermal growth factor (EGF) receptor tyrosine kinase or the nicotinic acetylcholine receptor (e.g., the IC50 or IC40 at such a receptor is preferably greater than 1 micromolar, and most preferably greater than 10 micromolar). Preferably, a modulator does not detectably inhibit EGF receptor activity or nicotinic acetylcholine receptor activity at a concentration of 0.5 micromolar, 1 micromolar or more preferably 10 micromolar. Assays for determining cell surface receptor activity are commercially available, and include the tyrosine kinase assay kits available from Panvera (Madison, Wis.). In certain embodiments, preferred VR1 modulators are non-sedating. In other words, a dose of VR1 modulator that is twice the minimum dose sufficient to provide analgesia in an animal model for determining pain relief (such as a model provided in Example 8, herein) causes only transient (i.e., lasting for no more than ½ the time that pain relief lasts) or preferably no statistically significant sedation in an animal model assay of sedation (using the method described by Fitzgerald et al. (1988) Toxicology 49(2-3):433-9). Preferably, a dose that is five times the minimum dose sufficient to provide analgesia does not produce statistically significant sedation. More preferably, a VR1 modulator provided herein does not produce sedation at intravenous doses of less than 25 mg/kg (preferably less than 10 mg/kg) or at oral doses of less than 140 mg/kg (preferably less than 50 mg/kg, more preferably less than 30 mg/kg). If desired, compounds provided herein may be evaluated for certain pharmacological properties including, but not limited to, oral bioavailability (preferred compounds are orally bioavailable to an extent allowing for therapeutically effective concentrations of the compound to be achieved at oral doses of less than 140 mg/kg, preferably less than 50 mg/kg, more preferably less than 30 mg/kg, even more preferably less than 10 mg/kg, still more preferably less than 1 mg/kg and most preferably less than 0.1 mg/kg), toxicity (a preferred compound is nontoxic when a therapeutically effective amount is administered to a subject), side effects (a preferred compound produces side effects comparable to placebo when a therapeutically effective amount of the compound is administered to a subject), serum protein binding and in vitro and in vivo half-life (a preferred compound exhibits an in vivo half-life allowing for Q.I.D. dosing, preferably T.I.D. dosing, more preferably B.I.D. dosing, and most preferably once-a-day dosing). In addition, differential penetration of the blood brain barrier may be desirable for VR1 modulators used to treat pain by modulating CNS VR1 activity such that total daily oral doses as described above provide such modulation to a therapeutically effective extent, while low brain levels of VR1 modulators used to treat peripheral nerve mediated pain may be preferred (i.e., such doses do not provide brain (e.g., CSF) levels of the compound sufficient to significantly modulate VR1 activity). Routine assays that are well known in the art may be used to assess these properties, and identify superior compounds for a particular use. For example, assays used to predict bioavailability include transport across human intestinal cell monolayers, including Caco-2 cell monolayers. Penetration of the blood brain barrier of a compound in humans may be predicted from the brain levels of the compound in laboratory animals given the compound (e.g., intravenously). Serum protein binding may be predicted from albumin binding assays. Compound half-life is inversely proportional to the frequency of dosage of a compound. In vitro half-lives of compounds may be predicted from assays of microsomal half-life as described, for example, within Example 7 of U.S. Patent Application Publication Number 2005/0070547. As noted above, preferred compounds provided herein are nontoxic. In general, the term “nontoxic” shall be understood in a relative sense and is intended to refer to any substance that has been approved by the United States Food and Drug Administration (“FDA”) for administration to mammals (preferably humans) or, in keeping with established criteria, is susceptible to approval by the FDA for administration to mammals (preferably humans). In addition, a highly preferred nontoxic compound generally satisfies one or more of the following criteria: (1) does not substantially inhibit cellular ATP production; (2) does not significantly prolong heart QT intervals; (3) does not cause substantial liver enlargement, or (4) does not cause substantial release of liver enzymes. As used herein, a compound that does not substantially inhibit cellular ATP production is a compound that satisfies the criteria set forth in Example 8 of U.S. Patent Application Publication Number 2005/0070547. In other words, cells treated as described therein with 100 μM of such a compound exhibit ATP levels that are at least 50% of the ATP levels detected in untreated cells. In more highly preferred embodiments, such cells exhibit ATP levels that are at least 80% of the ATP levels detected in untreated cells. A compound that does not significantly prolong heart QT intervals is a compound that does not result in a statistically significant prolongation of heart QT intervals (as determined by electrocardiography) in guinea pigs, minipigs or dogs upon administration of a dose that yields a serum concentration equal to the EC50 or IC50 for the compound. In certain preferred embodiments, a dose of 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 40 or 50 mg/kg administered parenterally or orally does not result in a statistically significant prolongation of heart QT intervals. A compound does not cause substantial liver enlargement if daily treatment of laboratory rodents (e.g., mice or rats) for 5-10 days with a dose that yields a serum concentration equal to the EC50 or IC50 for the compound results in an increase in liver to body weight ratio that is no more than 100% over matched controls. In more highly preferred embodiments, such doses do not cause liver enlargement of more than 75% or 50% over matched controls. If non-rodent mammals (e.g., dogs) are used, such doses should not result in an increase of liver to body weight ratio of more than 50%, preferably not more than 25%, and more preferably not more than 10% over matched untreated controls. Preferred doses within such assays include 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 40 or 50 mg/kg administered parenterally or orally. Similarly, a compound does not promote substantial release of liver enzymes if administration of twice the minimum dose that yields a serum concentration equal to the EC50 or IC50 at VR1 for the compound does not elevate serum levels of ALT, LDH or AST in laboratory animals (e.g., rodents) by more than 100% over matched mock-treated controls. In more highly preferred embodiments, such doses do not elevate such serum levels by more than 75% or 50% over matched controls. Alternatively, a compound does not promote substantial release of liver enzymes if, in an in vitro hepatocyte assay, concentrations (in culture media or other such solutions that are contacted and incubated with hepatocytes in vitro) that are equal to the EC50 or IC50 for the compound do not cause detectable release of any of such liver enzymes into culture medium above baseline levels seen in media from matched mock-treated control cells. In more highly preferred embodiments, there is no detectable release of any of such liver enzymes into culture medium above baseline levels when such compound concentrations are five-fold, and preferably ten-fold the EC50 or IC50 for the compound. In other embodiments, certain preferred compounds do not inhibit or induce microsomal cytochrome P450 enzyme activities, such as CYP1A2 activity, CYP2A6 activity, CYP2C9 activity, CYP2C19 activity, CYP2D6 activity, CYP2E1 activity or CYP3A4 activity at a concentration equal to the EC50 or IC50 at VR1 for the compound. Certain preferred compounds are not clastogenic (e.g., as determined using a mouse erythrocyte precursor cell micronucleus assay, an Ames micronucleus assay, a spiral micronucleus assay or the like) at a concentration equal the EC50 or IC50 for the compound. In other embodiments, certain preferred compounds do not induce sister chromatid exchange (e.g., in Chinese hamster ovary cells) at such concentrations. For detection purposes, as discussed in more detail below, VR1 modulators provided herein may be isotopically-labeled or radiolabeled. For example, compounds may have one or more atoms replaced by an atom of the same element having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be present in the compounds provided herein include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine and chlorine, such as 2H, 3H, 11C, 13C, 14C, 15N, 18O, 17O, 31P, 32P, 35S, 18F and 36Cl. In addition, substitution with heavy isotopes such as deuterium (i.e., 2H) can afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements and, hence, may be preferred in some circumstances. Preparation of 2-Phenoxy Pyrimidinone Analogues 2-Phenoxy pyrimidinone analogues may generally be prepared using standard synthetic methods. Starting materials are commercially available from suppliers such as Sigma-Aldrich Corp. (St. Louis, Mo.), or may be synthesized from commercially available precursors using established protocols. By way of example, a synthetic route similar to that shown in any of the following Schemes may be used, together with synthetic methods known in the art of synthetic organic chemistry. Each variable in the following schemes refers to any group consistent with the description of the compounds provided herein. Certain abbreviations used in the following Schemes and elsewhere herein include: CDCl3 deuterated chloroform δ chemical shift DCM dichloromethane DMAP 4-dimethylaminopyridine DMF dimethylformamide DMSO dimethylsulfoxide DPPF 1,1′-bis(diphenylphosphino)ferrocene Et ethyl EtOAc ethyl acetate EtOH ethanol h hour(s) 1H NMR proton nuclear magnetic resonance HPLC high pressure liquid chromatography Hz hertz KOtBu potassium tert-butoxide min minute(s) MS mass spectrometry (M+1) mass+1 Pd2(dba)3 tris(dibenzylidineacetone)dipalladium(0) RT room temperature TFA trifluoroacetic acid In certain embodiments, a compound provided herein may contain one or more asymmetric carbon atoms, so that the compound can exist in different stereoisomeric forms. Such forms can be, for example, racemates or optically active forms. As noted above, all stereoisomers are encompassed by the present invention. Nonetheless, it may be desirable to obtain single enantiomers (i.e., optically active forms). Standard methods for preparing single enantiomers include asymmetric synthesis and resolution of the racemates. Resolution of the racemates can be accomplished, for example, by conventional methods such as crystallization in the presence of a resolving agent, or chromatography using, for example a chiral HPLC column. Compounds may be radiolabeled by carrying out their synthesis using precursors comprising at least one atom that is a radioisotope. Each radioisotope is preferably carbon (e.g., 14C), hydrogen (e.g., 3H), sulfur (e.g., 35S), or iodine (e.g., 125I). Tritium labeled compounds may also be prepared catalytically via platinum-catalyzed exchange in tritiated acetic acid, acid-catalyzed exchange in tritiated trifluoroacetic acid, or heterogeneous-catalyzed exchange with tritium gas using the compound as substrate. In addition, certain precursors may be subjected to tritium-halogen exchange with tritium gas, tritium gas reduction of unsaturated bonds, or reduction using sodium borotritide, as appropriate. Preparation of radiolabeled compounds may be conveniently performed by a radioisotope supplier specializing in custom synthesis of radiolabeled probe compounds. Pharmaceutical Compositions The present invention also provides pharmaceutical compositions comprising one or more compounds provided herein, together with at least one physiologically acceptable carrier or excipient. Pharmaceutical compositions may comprise, for example, one or more of water, buffers (e.g., neutral buffered saline or phosphate buffered saline), ethanol, mineral oil, vegetable oil, dimethylsulfoxide, carbohydrates (e.g., glucose, mannose, sucrose or dextrans), mannitol, proteins, adjuvants, polypeptides or amino acids such as glycine, antioxidants, chelating agents such as EDTA or glutathione and/or preservatives. In addition, other active ingredients may (but need not) be included in the pharmaceutical compositions provided herein. Pharmaceutical compositions may be formulated for any appropriate manner of administration, including, for example, topical, oral, nasal, rectal or parenteral administration. The term parenteral as used herein includes subcutaneous, intradermal, intravascular (e.g., intravenous), intramuscular, spinal, intracranial, intrathecal and intraperitoneal injection, as well as any similar injection or infusion technique. In certain embodiments, compositions suitable for oral use are preferred. Such compositions include, for example, tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsion, hard or soft capsules, or syrups or elixirs. Within yet other embodiments, pharmaceutical compositions may be formulated as a lyophilizate. Formulation for topical administration may be preferred for certain conditions (e.g., in the treatment of skin conditions such as burns or itch). Formulation for direct administration into the bladder (intravesicular administration) may be preferred for treatment of urinary incontinence and overactive bladder. Compositions intended for oral use may further comprise one or more components such as sweetening agents, flavoring agents, coloring agents and/or preserving agents in order to provide appealing and palatable preparations. Tablets contain the active ingredient in admixture with physiologically acceptable excipients that are suitable for the manufacture of tablets. Such excipients include, for example, inert diluents (e.g., calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate), granulating and disintegrating agents (e.g., corn starch or alginic acid), binding agents (e.g., starch, gelatin or acacia) and lubricating agents (e.g., magnesium stearate, stearic acid or talc). Tablets may be formed using standard techniques, including dry granulation, direct compression and wet granulation. The tablets may be uncoated or they may be coated by known techniques. Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent (e.g., calcium carbonate, calcium phosphate or kaolin), or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium (e.g., peanut oil, liquid paraffin or olive oil). Aqueous suspensions contain the active material(s) in admixture with suitable excipients, such as suspending agents (e.g., sodium carboxymethylcellulose, methylcellulose, hydropropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia); and dispersing or wetting agents (e.g., naturally-occurring phosphatides such as lecithin, condensation products of an alkylene oxide with fatty acids such as polyoxyethylene stearate, condensation products of ethylene oxide with long chain aliphatic alcohols such as heptadecaethyleneoxycetanol, condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides such as polyethylene sorbitan monooleate). Aqueous suspensions may also comprise one or more preservatives, such as ethyl or n-propyl p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and/or one or more sweetening agents, such as sucrose or saccharin. Oily suspensions may be formulated by suspending the active ingredient(s) in a vegetable oil (e.g., arachis oil, olive oil, sesame oil or coconut oil) or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent such as beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth above, and/or flavoring agents may be added to provide palatable oral preparations. Such suspensions may be preserved by the addition of an anti-oxidant such as ascorbic acid. Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, a suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, such as sweetening, flavoring and coloring agents, may also be present. Pharmaceutical compositions may also be formulated as oil-in-water emulsions. The oily phase may be a vegetable oil (e.g., olive oil or arachis oil), a mineral oil (e.g., liquid paraffin) or a mixture thereof. Suitable emulsifying agents include naturally-occurring gums (e.g., gum acacia or gum tragacanth), naturally-occurring phosphatides (e.g., soy bean lecithin, and esters or partial esters derived from fatty acids and hexitol), anhydrides (e.g., sorbitan monoleate) and condensation products of partial esters derived from fatty acids and hexitol with ethylene oxide (e.g., polyoxyethylene sorbitan monoleate). An emulsion may also comprise one or more sweetening and/or flavoring agents. Syrups and elixirs may be formulated with sweetening agents, such as glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also comprise one or more demulcents, preservatives, flavoring agents and/or coloring agents. Formulations for topical administration typically comprise a topical vehicle combined with active agent(s), with or without additional optional components. Suitable topical vehicles and additional components are well known in the art, and it will be apparent that the choice of a vehicle will depend on the particular physical form and mode of delivery. Topical vehicles include water; organic solvents such as alcohols (e.g., ethanol or isopropyl alcohol) or glycerin; glycols (e.g., butylene, isoprene or propylene glycol); aliphatic alcohols (e.g., lanolin); mixtures of water and organic solvents and mixtures of organic solvents such as alcohol and glycerin; lipid-based materials such as fatty acids, acylglycerols (including oils, such as mineral oil, and fats of natural or synthetic origin), phosphoglycerides, sphingolipids and waxes; protein-based materials such as collagen and gelatin; silicone-based materials (both non-volatile and volatile); and hydrocarbon-based materials such as microsponges and polymer matrices. A composition may further include one or more components adapted to improve the stability or effectiveness of the applied formulation, such as stabilizing agents, suspending agents, emulsifying agents, viscosity adjusters, gelling agents, preservatives, antioxidants, skin penetration enhancers, moisturizers and sustained release materials. Examples of such components are described in Martindale—The Extra Pharmacopoeia (Pharmaceutical Press, London 1993) and Remington: The Science and Practice of Pharmacy, 21st ed., Lippincott Williams & Wilkins, Philadelphia, Pa. (2005). Formulations may comprise microcapsules, such as hydroxymethylcellulose or gelatin-microcapsules, liposomes, albumin microspheres, microemulsions, nanoparticles or nanocapsules. A topical formulation may be prepared in any of a variety of physical forms including, for example, solids, pastes, creams, foams, lotions, gels, powders, aqueous liquids and emulsions. The physical appearance and viscosity of such pharmaceutically acceptable forms can be governed by the presence and amount of emulsifier(s) and viscosity adjuster(s) present in the formulation. Solids are generally firm and non-pourable and commonly are formulated as bars or sticks, or in particulate form; solids can be opaque or transparent, and optionally can contain solvents, emulsifiers, moisturizers, emollients, fragrances, dyes/colorants, preservatives and other active ingredients that increase or enhance the efficacy of the final product. Creams and lotions are often similar to one another, differing mainly in their viscosity; both lotions and creams may be opaque, translucent or clear and often contain emulsifiers, solvents, and viscosity adjusting agents, as well as moisturizers, emollients, fragrances, dyes/colorants, preservatives and other active ingredients that increase or enhance the efficacy of the final product. Gels can be prepared with a range of viscosities, from thick or high viscosity to thin or low viscosity. These formulations, like those of lotions and creams, may also contain solvents, emulsifiers, moisturizers, emollients, fragrances, dyes/colorants, preservatives and other active ingredients that increase or enhance the efficacy of the final product. Liquids are thinner than creams, lotions, or gels and often do not contain emulsifiers. Liquid topical products often contain solvents, emulsifiers, moisturizers, emollients, fragrances, dyes/colorants, preservatives and other active ingredients that increase or enhance the efficacy of the final product. Suitable emulsifiers for use in topical formulations include, but are not limited to, ionic emulsifiers, cetearyl alcohol, non-ionic emulsifiers like polyoxyethylene oleyl ether, PEG-40 stearate, ceteareth-12, ceteareth-20, ceteareth-30, ceteareth alcohol, PEG-100 stearate and glyceryl stearate. Suitable viscosity adjusting agents include, but are not limited to, protective colloids or non-ionic gums such as hydroxyethylcellulose, xanthan gum, magnesium aluminum silicate, silica, microcrystalline wax, beeswax, paraffin, and cetyl palmitate. A gel composition may be formed by the addition of a gelling agent such as chitosan, methyl cellulose, ethyl cellulose, polyvinyl alcohol, polyquaterniums, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carbomer or ammoniated glycyrrhizinate. Suitable surfactants include, but are not limited to, nonionic, amphoteric, ionic and anionic surfactants. For example, one or more of dimethicone copolyol, polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80, lauramide DEA, cocamide DEA, and cocamide MEA, oleyl betaine, cocamidopropyl phosphatidyl PG-dimonium chloride, and ammonium laureth sulfate may be used within topical formulations. Suitable preservatives include, but are not limited to, antimicrobials such as methylparaben, propylparaben, sorbic acid, benzoic acid, and formaldehyde, as well as physical stabilizers and antioxidants such as vitamin E, sodium ascorbate/ascorbic acid and propyl gallate. Suitable moisturizers include, but are not limited to, lactic acid and other hydroxy acids and their salts, glycerin, propylene glycol, and butylene glycol. Suitable emollients include lanolin alcohol, lanolin, lanolin derivatives, cholesterol, petrolatum, isostearyl neopentanoate and mineral oils. Suitable fragrances and colors include, but are not limited to, FD&C Red No. 40 and FD&C Yellow No. 5. Other suitable additional ingredients that may be included a topical formulation include, but are not limited to, abrasives, absorbents, anti-caking agents, anti-foaming agents, anti-static agents, astringents (e.g., witch hazel, alcohol and herbal extracts such as chamomile extract), binders/excipients, buffering agents, chelating agents, film forming agents, conditioning agents, propellants, opacifying agents, pH adjusters and protectants. An example of a suitable topical vehicle for formulation of a gel is: hydroxypropylcellulose (2.1%); 70/30 isopropyl alcohol/water (90.9%); propylene glycol (5.1%); and Polysorbate 80 (1.9%). An example of a suitable topical vehicle for formulation as a foam is: cetyl alcohol (1.1%); stearyl alcohol (0.5%; Quaternium 52 (1.0%); propylene glycol (2.0%); ethanol 95 PGF3 (61.05%); deionized water (30.05%); P75 hydrocarbon propellant (4.30%). All percents are by weight. Typical modes of delivery for topical compositions include application using the fingers; application using a physical applicator such as a cloth, tissue, swab, stick or brush; spraying (including mist, aerosol or foam spraying); dropper application; sprinkling; soaking; and rinsing. A pharmaceutical composition may be prepared as a sterile injectible aqueous or oleaginous suspension. The compound(s) provided herein, depending on the vehicle and concentration used, can either be suspended or dissolved in the vehicle. Such a composition may be formulated according to the known art using suitable dispersing, wetting agents and/or suspending agents such as those mentioned above. Among the acceptable vehicles and solvents that may be employed are water, 1,3-butanediol, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils may be employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed, including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectible compositions, and adjuvants such as local anesthetics, preservatives and/or buffering agents can be dissolved in the vehicle. Pharmaceutical compositions may also be formulated as suppositories (e.g., for rectal administration). Such compositions can be prepared by mixing the drug with a suitable non-irritating excipient that is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drug. Suitable excipients include, for example, cocoa butter and polyethylene glycols. Compositions for inhalation typically can be provided in the form of a solution, suspension or emulsion that can be administered as a dry powder or in the form of an aerosol using a conventional propellant (e.g., dichlorodifluoromethane or trichlorofluoromethane). Pharmaceutical compositions may be formulated for release at a pre-determined rate. Instantaneous release may be achieved, for example, via sublingual administration (i.e., administration by mouth in such a way that the active ingredient(s) are rapidly absorbed via the blood vessels under the tongue rather than via the digestive tract). Controlled release formulations (i.e., formulations such as a capsule, tablet or coated tablet that slows and/or delays release of active ingredient(s) following administration) may be administered by, for example, oral, rectal or subcutaneous implantation, or by implantation at a target site. In general, a controlled release formulation comprises a matrix and/or coating that delays disintegration and absorption in the gastrointestinal tract (or implantation site) and thereby provides a delayed action or a sustained action over a longer period. One type of controlled-release formulation is a sustained-release formulation, in which at least one active ingredient is continuously released over a period of time at a constant rate. Preferably, the therapeutic agent is released at such a rate that blood (e.g., plasma) concentrations are maintained within the therapeutic range, but below toxic levels, over a period of time that is at least 4 hours, preferably at least 8 hours, and more preferably at least 12 hours. Such formulations may generally be prepared using well known technology and administered by, for example, oral, rectal or subcutaneous implantation, or by implantation at the desired target site. Carriers for use within such formulations are biocompatible, and may also be biodegradable; preferably the formulation provides a relatively constant level of modulator release. The amount of modulator contained within a sustained release formulation depends upon, for example, the site of implantation, the rate and expected duration of release and the nature of the condition to be treated or prevented. Controlled release may be achieved by combining the active ingredient(s) with a matrix material that itself alters release rate and/or through the use of a controlled-release coating. The release rate can be varied using methods well known in the art, including (a) varying the thickness or composition of coating, (b) altering the amount or manner of addition of plasticizer in a coating, (c) including additional ingredients, such as release-modifying agents, (d) altering the composition, particle size or particle shape of the matrix, and (e) providing one or more passageways through the coating. The amount of modulator contained within a sustained release formulation depends upon, for example, the method of administration (e.g., the site of implantation), the rate and expected duration of release and the nature of the condition to be treated or prevented. The matrix material, which itself may or may not serve a controlled-release function, is generally any material that supports the active ingredient(s). For example, a time delay material such as glyceryl monosterate or glyceryl distearate may be employed. Active ingredient(s) may be combined with matrix material prior to formation of the dosage form (e.g., a tablet). Alternatively, or in addition, active ingredient(s) may be coated on the surface of a particle, granule, sphere, microsphere, bead or pellet that comprises the matrix material. Such coating may be achieved by conventional means, such as by dissolving the active ingredient(s) in water or other suitable solvent and spraying. Optionally, additional ingredients are added prior to coating (e.g., to assist binding of the active ingredient(s) to the matrix material or to color the solution). The matrix may then be coated with a barrier agent prior to application of controlled-release coating. Multiple coated matrix units may, if desired, be encapsulated to generate the final dosage form. In certain embodiments, a controlled release is achieved through the use of a controlled release coating (i.e., a coating that permits release of active ingredient(s) at a controlled rate in aqueous medium). The controlled release coating should be a strong, continuous film that is smooth, capable of supporting pigments and other additives, non-toxic, inert and tack-free. Coatings that regulate release of the modulator include pH-independent coatings, pH-dependent coatings (which may be used to release modulator in the stomach) and enteric coatings (which allow the formulation to pass intact through the stomach and into the small intestine, where the coating dissolves and the contents are absorbed by the body). It will be apparent that multiple coatings may be employed (e.g., to allow release of a portion of the dose in the stomach and a portion further along the gastrointestinal tract). For example, a portion of active ingredient(s) may be coated over an enteric coating, and thereby released in the stomach, while the remainder of active ingredient(s) in the matrix core is protected by the enteric coating and released further down the GI tract. pH dependent coatings include, for example, shellac, cellulose acetate phthalate, polyvinyl acetate phthalate, hydroxypropylmethylcellulose phthalate, methacrylic acid ester copolymers and zein. In certain embodiments, the coating is a hydrophobic material, preferably used in an amount effective to slow the hydration of the gelling agent following administration. Suitable hydrophobic materials include alkyl celluloses (e.g., ethylcellulose or carboxymethylcellulose), cellulose ethers, cellulose esters, acrylic polymers (e.g., poly(acrylic acid), poly(methacrylic acid), acrylic acid and methacrylic acid copolymers, methyl methacrylate copolymers, ethoxy ethyl methacrylates, cyanoethyl methacrylate, methacrylic acid alkamide copolymer, poly(methyl methacrylate), polyacrylamide, ammonio methacrylate copolymers, aminoalkyl methacrylate copolymer, poly(methacrylic acid anhydride) and glycidyl methacrylate copolymers) and mixtures of the foregoing. Representative aqueous dispersions of ethylcellulose include, for example, AQUACOAT® (FMC Corp., Philadelphia, Pa.) and SURELEASE® (Colorcon, Inc., West Point, Pa.), both of which can be applied to the substrate according to the manufacturer's instructions. Representative acrylic polymers include, for example, the various EUDRAGIT® (Rohm America, Piscataway, N.J.) polymers, which may be used singly or in combination depending on the desired release profile, according to the manufacturer's instructions. The physical properties of coatings that comprise an aqueous dispersion of a hydrophobic material may be improved by the addition or one or more plasticizers. Suitable plasticizers for alkyl celluloses include, for example, dibutyl sebacate, diethyl phthalate, triethyl citrate, tributyl citrate and triacetin. Suitable plasticizers for acrylic polymers include, for example, citric acid esters such as triethyl citrate and tributyl citrate, dibutyl phthalate, polyethylene glycols, propylene glycol, diethyl phthalate, castor oil and triacetin. Controlled-release coatings are generally applied using conventional techniques, such as by spraying in the form of an aqueous dispersion. If desired, the coating may comprise pores or channels or to facilitate release of active ingredient. Pores and channels may be generated by well known methods, including the addition of organic or inorganic material that is dissolved, extracted or leached from the coating in the environment of use. Certain such pore-forming materials include hydrophilic polymers, such as hydroxyalkylcelluloses (e.g., hydroxypropylmethylcellulose), cellulose ethers, synthetic water-soluble polymers (e.g., polyvinylpyrrolidone, cross-linked polyvinylpyrrolidone and polyethylene oxide), water-soluble polydextrose, saccharides and polysaccharides and alkali metal salts. Alternatively, or in addition, a controlled release coating may include one or more orifices, which may be formed my methods such as those described in U.S. Pat. Nos. 3,845,770; 4,034,758; 4,077,407; 4,088,864; 4,783,337 and 5,071,607. Controlled-release may also be achieved through the use of transdermal patches, using conventional technology (see, e.g., U.S. Pat. No. 4,668,232). Further examples of controlled release formulations, and components thereof, may be found, for example, in U.S. Pat. Nos. 5,524,060; 4,572,833; 4,587,117; 4,606,909; 4,610,870; 4,684,516; 4,777,049; 4,994,276; 4,996,058; 5,128,143; 5,202,128; 5,376,384; 5,384,133; 5,445,829; 5,510,119; 5,618,560; 5,643,604; 5,891,474; 5,958,456; 6,039,980; 6,143,353; 6,126,969; 6,156,342; 6,197,347; 6,387,394; 6,399,096; 6,437,000; 6,447,796; 6,475,493; 6,491,950; 6,524,615; 6,838,094; 6,905,709; 6,923,984; 6,923,988; and 6,911,217; each of which is hereby incorporated by reference for its teaching of the preparation of controlled release dosage forms. In addition to or together with the above modes of administration, a compound provided herein may be conveniently added to food or drinking water (e.g., for administration to non-human animals including companion animals (such as dogs and cats) and livestock). Animal feed and drinking water compositions may be formulated so that the animal takes in an appropriate quantity of the composition along with its diet. It may also be convenient to present the composition as a premix for addition to feed or drinking water. Compounds are generally administered in a therapeutically effective amount. Preferred systemic doses are no higher than 50 mg per kilogram of body weight per day (e.g., ranging from about 0.001 mg to about 50 mg per kilogram of body weight per day), with oral doses generally being about 5-20 fold higher than intravenous doses (e.g., ranging from 0.01 to 40 mg per kilogram of body weight per day). The amount of active ingredient that may be combined with the carrier materials to produce a single dosage unit will vary depending, for example, upon the patient being treated, the particular mode of administration and any other co-administered drugs. Dosage units generally contain between from about 10 μg to about 500 mg of active ingredient. Optimal dosages may be established using routine testing, and procedures that are well known in the art. Pharmaceutical compositions may be packaged for treating conditions responsive to VR1 modulation (e.g., treatment of exposure to vanilloid ligand or other irritant, pain, itch, obesity or urinary incontinence). Packaged pharmaceutical compositions generally include (i) a container holding a pharmaceutical composition that comprises at least one VR1 modulator as described herein and (ii) instructions (e.g., labeling or a package insert) indicating that the contained composition is to be used for treating a condition responsive to VR1 modulation in the patient. Methods of Use VR1 modulators provided herein may be used to alter activity and/or activation of capsaicin receptors in a variety of contexts, both in vitro and in vivo. Within certain aspects, VR1 antagonists may be used to inhibit the binding of vanilloid ligand agonist (such as capsaicin and/or RTX) to capsaicin receptor in vitro or in vivo. In general, such methods comprise the step of contacting a capsaicin receptor with one or more VR1 modulators provided herein, in the presence of vanilloid ligand in aqueous solution and under conditions otherwise suitable for binding of the ligand to capsaicin receptor. The VR1 modulator(s) are generally present at a concentration that is sufficient to alter the binding of vanilloid ligand to VR1 in vitro (using the assay provided in Example 5) and/or VR1-mediated signal transduction (using an assay provided in Example 6). The capsaicin receptor may be present in solution or suspension (e.g., in an isolated membrane or cell preparation), or in a cultured or isolated cell. Within certain embodiments, the capsaicin receptor is expressed by a neuronal cell present in a patient, and the aqueous solution is a body fluid. Preferably, one or more VR1 modulators are administered to an animal in an amount such that the VR1 modulator is present in at least one body fluid of the animal at a therapeutically effective concentration that is 1 micromolar or less; preferably 500 nanomolar or less; more preferably 100 nanomolar or less, 50 nanomolar or less, 20 nanomolar or less, or 10 nanomolar or less. For example, such compounds may be administered at a therapeutically effective dose that is less than 20 mg/kg body weight, preferably less than 5 mg/kg and, in some instances, less than 1 mg/kg. Also provided herein are methods for modulating, preferably reducing, the signal-transducing activity (i.e., the calcium conductance) of a cellular capsaicin receptor. Such modulation may be achieved by contacting a capsaicin receptor (either in vitro or in vivo) with one or more VR1 modulators provided herein under conditions suitable for binding of the modulator(s) to the receptor. The VR1 modulator(s) are generally present at a concentration that is sufficient to alter the binding of vanilloid ligand to VR1 in vitro and/or VR1-mediated signal transduction as described herein. The receptor may be present in solution or suspension, in a cultured or isolated cell preparation or in a cell within a patient. For example, the cell may be a neuronal cell that is contacted in vivo in an animal. Alternatively, the cell may be an epithelial cell, such as a urinary bladder epithelial cell (urothelial cell) or an airway epithelial cell that is contacted in vivo in an animal. Modulation of signal tranducing activity may be assessed by detecting an effect on calcium ion conductance (also referred to as calcium mobilization or flux). Modulation of signal transducing activity may alternatively be assessed by detecting an alteration of a symptom (e.g., pain, burning sensation, broncho-constriction, inflammation, cough, hiccup, itch, menopause symptoms, urinary incontinence or overactive bladder) of a patient being treated with one or more VR1 modulators provided herein. VR1 modulator(s) provided herein are preferably administered to a patient (e.g., a human) orally or topically, and are present within at least one body fluid of the animal while modulating VR1 signal-transducing activity. Preferred VR1 modulators for use in such methods modulate VR1 signal-transducing activity in vitro at a concentration of 1 nanomolar or less, preferably 100 picomolar or less, more preferably 20 picomolar or less, and in vivo at a concentration of 1 micromolar or less, 500 nanomolar or less, or 100 nanomolar or less in a body fluid such as blood. The present invention further provides methods for treating conditions responsive to VR1 modulation. Within the context of the present invention, the term “treatment” encompasses both disease-modifying treatment and symptomatic treatment, either of which may be prophylactic (i.e., before the onset of symptoms, in order to prevent, delay or reduce the severity of symptoms) or therapeutic (i.e., after the onset of symptoms, in order to reduce the severity and/or duration of symptoms). A condition is “responsive to VR1 modulation” if it is characterized by inappropriate activity of a capsaicin receptor, regardless of the amount of vanilloid ligand present locally, and/or if modulation of capsaicin receptor activity results in alleviation of the condition or a symptom thereof. Such conditions include, for example, symptoms resulting from exposure to VR1-activating stimuli, pain, respiratory disorders (such as cough, asthma, chronic obstructive pulmonary disease, chronic bronchitis, cystic fibrosis and rhinitis, including allergic rhinitis, such as seasonal an perennial rhinitis, and non-allergic rhinitis), depression, itch, menopause symptoms, urinary incontinence, overactive bladder, acoustic injury (e.g., of the cochlea), tinnitus, hyperacusis, diabetes and prediabetic conditions (e.g., insulin resistance or glucose tolerance), hiccup and obesity, as described in more detail below. Such conditions may be diagnosed and monitored using criteria that have been established in the art. Patients may include humans, domesticated companion animals and livestock, with dosages as described above. Treatment regimens may vary depending on the compound used and the particular condition to be treated; however, for treatment of most disorders, a frequency of administration of 4 times daily or less is preferred. In general, a dosage regimen of 2 times daily is more preferred, with once a day dosing particularly preferred. For the treatment of acute pain, a single dose that rapidly reaches effective concentrations is desirable. It will be understood, however, that the specific dose level and treatment regimen for any particular patient will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, sex, diet, time of administration, route of administration, and rate of excretion, drug combination and the severity of the particular disease undergoing therapy. In general, the use of the minimum dose sufficient to provide effective therapy is preferred. Patients may generally be monitored for therapeutic effectiveness using medical or veterinary criteria suitable for the condition being treated or prevented. Patients experiencing symptoms resulting from exposure to capsaicin receptor-activating stimuli include individuals with burns caused by heat, light, tear gas or acid and those whose mucous membranes are exposed (e.g., via ingestion, inhalation or eye contact) to capsaicin (e.g., from hot peppers or in pepper spray) or a related irritant such as acid, tear gas, infectious agent(s) or air pollutant(s). The resulting symptoms (which may be treated using VR1 modulators, especially antagonists, provided herein) may include, for example, pain, broncho-constriction and inflammation. Pain that may be treated using the VR1 modulators provided herein may be chronic or acute and includes, but is not limited to, peripheral nerve-mediated pain (especially neuropathic pain). Compounds provided herein may be used in the treatment of, for example, postmastectomy pain syndrome, stump pain, phantom limb pain, oral neuropathic pain, toothache (dental pain), denture pain, postherpetic neuralgia, diabetic neuropathy, chemotherapy-induced neuropathy, reflex sympathetic dystrophy, trigeminal neuralgia, osteoarthritis, rheumatoid arthritis, fibromyalgia, Guillain-Barre syndrome, meralgia paresthetica, burning-mouth syndrome and/or pain associated with nerve and root damage, including as pain associated with peripheral nerve disorders (e.g., nerve entrapment and brachial plexus avulsions, amputation, peripheral neuropathies including bilateral peripheral neuropathy, tic douloureux, atypical facial pain, nerve root damage, and arachnoiditis). Additional neuropathic pain conditions include causalgia (reflex sympathetic dystrophy—RSD, secondary to injury of a peripheral nerve), neuritis (including, for example, sciatic neuritis, peripheral neuritis, polyneuritis, optic neuritis, postfebrile neuritis, migrating neuritis, segmental neuritis and Gombault's neuritis), neuronitis, neuralgias (e.g., those mentioned above, cervicobrachial neuralgia, cranial neuralgia, geniculate neuralgia, glossopharyngial neuralgia, migranous neuralgia, idiopathic neuralgia, intercostals neuralgia, mammary neuralgia, mandibular joint neuralgia, Morton's neuralgia, nasociliary neuralgia, occipital neuralgia, red neuralgia, Sluder's neuralgia, splenopalatine neuralgia, supraorbital neuralgia and vidian neuralgia), surgery-related pain, musculoskeletal pain, myofascial pain syndromes, AIDS-related neuropathy, MS-related neuropathy, central nervous system pain (e.g., pain due to brain stem damage, sciatica, and ankylosing spondylitis), and spinal pain, including spinal cord injury-related pain. Headache, including headaches involving peripheral nerve activity may also be treated as described herein. Such pain includes, for example, such as sinus, cluster (i.e., migranous neuralgia) and tension headaches, migraine, temporomandibular pain and maxillary sinus pain. For example, migraine headaches may be prevented by administration of a compound provided herein as soon as a pre-migrainous aura is experienced by the patient. Further conditions that can be treated as described herein include Charcot's pains, intestinal gas pains, ear pain, heart pain, muscle pain, eye pain, orofacial pain (e.g., odontalgia), abdominal pain, gynaecological pain (e.g., menstrual pain, dysmenorrhoea, pain associated with cystitis, labor pain, chronic pelvic pain, chronic prostitis and endometriosis), acute and chronic back pain (e.g., lower back pain), gout, scar pain, hemorrhoidal pain, dyspeptic pains, angina, nerve root pain, “non-painful” neuropathies, complex regional pain syndrome, homotopic pain and heterotopic pain—including pain associated with carcinoma, often referred to as cancer pain (e.g., in patients with bone cancer), pain (and inflammation) associated with venom exposure (e.g., due to snake bite, spider bite, or insect sting) and trauma associated pain (e.g., post-surgical pain, episiotomy pain, pain from cuts, musculoskeletal pain, bruises and broken bones, and burn pain, especially primary hyperalgesia associated therewith). Additional pain conditions that may be treated as described herein include pain associated with respiratory disorders as described above, autoimmune diseases, immunodeficiency disorders, hot flashes, inflammatory bowel disease, gastroesophageal reflux disease (GERD), irritable bowel syndrome and/or inflammatory bowel disease. Within certain aspects, VR1 modulators provided herein may be used for the treatment of mechanical pain. As used herein, the term “mechanical pain” refers to pain other than headache pain that is not neuropathic or a result of exposure to heat, cold or external chemical stimuli. Mechanical pain includes physical trauma (other than thermal or chemical burns or other irritating and/or painful exposures to noxious chemicals) such as post-surgical pain and pain from cuts, bruises and broken bones; toothache; denture pain; nerve root pain; osteoarthritis; rheumatoid arthritis; fibromyalgia; meralgia paresthetica; back pain; cancer-associated pain; angina; carpel tunnel syndrome; and pain resulting from bone fracture, labor, hemorrhoids, intestinal gas, dyspepsia, and menstruation. Itching conditions that may be treated include psoriatic pruritus, itch due to hemodialysis, aguagenic pruritus, and itching associated with vulvar vestibulitis, contact dermatitis, insect bites and skin allergies. Urinary tract conditions that may be treated as described herein include urinary incontinence (including overflow incontinence, urge incontinence and stress incontinence), as well as overactive or unstable bladder conditions (including bladder detrusor hyper-reflexia, detrusor hyper-reflexia of spinal origin and bladder hypersensitivity). In certain such treatment methods, VR1 modulator is administered via a catheter or similar device, resulting in direct injection of VR1 modulator into the bladder. Compounds provided herein may also be used as anti-tussive agents (to prevent, relieve or suppress coughing, including cough induced by medications such as ACE inhibitors) and for the treatment of hiccup, for the treatment of menopause symptoms such as hot flashes, and to promote weight loss in an obese patient. Within other aspects, VR1 modulators provided herein may be used within combination therapy for the treatment of conditions involving pain and/or inflammatory components. Such conditions include, for example, autoimmune disorders and pathologic autoimmune responses known to have an inflammatory component including, but not limited to, arthritis (especially rheumatoid arthritis), psoriasis, Crohn's disease, lupus erythematosus, irritable bowel syndrome, tissue graft rejection, and hyperacute rejection of transplanted organs. Other such conditions include trauma (e.g., injury to the head or spinal cord), cardio- and cerebro-vascular disease and certain infectious diseases. Suitable dosages for VR1 modulator within such combination therapy are generally as described above. Dosages and methods of administration of anti-inflammatory agents can be found, for example, in the manufacturer's instructions in the Physician's Desk Reference. In certain embodiments, the combination administration of a VR1 modulator with an anti-inflammatory agent results in a reduction of the dosage of the anti-inflammatory agent required to produce a therapeutic effect (i.e., a decrease in the minimum therapeutically effective amount). Thus, preferably, the dosage of anti-inflammatory agent in a combination or combination treatment method is less than the maximum dose advised by the manufacturer for administration of the anti-inflammatory agent without combination administration of a VR1 antagonist. More preferably this dosage is less than ¾, even more preferably less than ½, and highly preferably, less than ¼ of the maximum dose, while most preferably the dose is less than 10% of the maximum dose advised by the manufacturer for administration of the anti-inflammatory agent(s) when administered without combination administration of a VR1 antagonist. It will be apparent that the dosage amount of VR1 antagonist component of the combination needed to achieve the desired effect may similarly be affected by the dosage amount and potency of the anti-inflammatory agent component of the combination. In certain preferred embodiments, the combination administration of a VR1 modulator with an anti-inflammatory agent is accomplished by packaging one or more VR1 modulators and one or more anti-inflammatory agents in the same package, either in separate containers within the package or in the same contained as a mixture of one or more VR1 antagonists and one or more anti-inflammatory agents. Preferred mixtures are formulated for oral administration (e.g., as pills, capsules, tablets or the like). In certain embodiments, the package comprises a label bearing indicia indicating that the one or more VR1 modulators and one or more anti-inflammatory agents are to be taken together for the treatment of an inflammatory pain condition. Within further aspects, VR1 modulators provided herein may be used in combination with one or more additional pain relief medications. Certain such medications are also anti-inflammatory agents, and are listed above. Other such medications are analgesic agents, including narcotic agents which typically act at one or more opioid receptor subtypes (e.g., μ, κ and/or δ), preferably as agonists or partial agonists. Such agents include opiates, opiate derivatives and opioids, as well as pharmaceutically acceptable salts and hydrates thereof. Specific examples of narcotic analgesics include, within preferred embodiments, alfentanil, alphaprodine, anileridine, bezitramide, buprenorphine, butorphanol, codeine, diacetyldihydromorphine, diacetylmorphine, dihydrocodeine, diphenoxylate, ethylmorphine, fentanyl, heroin, hydrocodone, hydromorphone, isomethadone, levomethorphan, levorphane, levorphanol, meperidine, metazocine, methadone, methorphan, metopon, morphine, nalbuphine, opium extracts, opium fluid extracts, powdered opium, granulated opium, raw opium, tincture of opium, oxycodone, oxymorphone, paregoric, pentazocine, pethidine, phenazocine, piminodine, propoxyphene, racemethorphan, racemorphan, sulfentanyl, thebaine and pharmaceutically acceptable salts and hydrates of the foregoing agents. Other examples of narcotic analgesic agents include acetorphine, acetyldihydrocodeine, acetylmethadol, allylprodine, alphracetylmethadol, alphameprodine, alphamethadol, benzethidine, benzylmorphine, betacetylmethadol, betameprodine, betamethadol, betaprodine, clonitazene, codeine methylbromide, codeine-N-oxide, cyprenorphine, desomorphine, dextromoramide, diampromide, diethylthiambutene, dihydromorphine, dimenoxadol, dimepheptanol, dimethylthiamubutene, dioxaphetyl butyrate, dipipanone, drotebanol, ethanol, ethylmethylthiambutene, etonitazene, etorphine, etoxeridine, furethidine, hydromorphinol, hydroxypethidine, ketobemidone, levomoramide, levophenacylmorphan, methyldesorphine, methyldihydromorphine, morpheridine, morphine methylpromide, morphine methylsulfonate, morphine-N-oxide, myrophin, naloxone, naltyhexone, nicocodeine, nicomorphine, noracymethadol, norlevorphanol, normethadone, normorphine, norpipanone, pentazocaine, phenadoxone, phenampromide, phenomorphan, phenoperidine, piritramide, pholcodine, proheptazoine, properidine, propiran, racemoramide, thebacon, trimeperidine and the pharmaceutically acceptable salts and hydrates thereof. Further specific representative analgesic agents include, for example acetaminophen (paracetamol); ibuprofen; aspirin and other NSAIDs described above; NR2B antagonists; bradykinin antagonists; anti-migraine agents; anticonvulsants such as oxcarbazepine and carbamazepine; antidepressants (such as TCAs, SSRIs, SNRIs, substance P antagonists, etc.); spinal blocks; pentazocine/naloxone; meperidine; levorphanol; buprenorphine; hydromorphone; fentanyl; sufentanyl; oxycodone; oxycodone/acetaminophen, nalbuphine and oxymorphone. Still further analgesic agents include CB2-receptor agonists, such as AM1241, capsaicin receptor antagonists and compounds that bind to the α2δ subunit of voltage-gated calcium channels, such as gabapentin and pregabalin. Representative anti-migraine agents for use in combination with a VR1 modulator provided herein include CGRP antagonists, ergotamines and 5-HT1 agonists, such as sumatripan, naratriptan, zolmatriptan and rizatriptan. Within still further aspects, modulators provided herein may be used, for example, in the treatment of pulmonary disorders such as asthma, in combination with one or more beta(2)-adrenergic receptor agonists or leukotriene receptor antagonists (e.g., agents that inhibits the cysteinyl leukotriene CysLT1 receptor). CysLT1 antagonists include montelukast, zafirlukast, and pranlukast. For the treatment or prevention of cough, a VR1 modulator as provided herein may be used in combination with other medication designed to treat this condition, such as antibiotics, anti-inflammatory agents, cystinyl leukotrienes, histamine antagonists, corticosteroids, opioids, NMDA antagonists, proton pump inhibitors, nociceptin, neurokinin (NK1, NK2 and NK3) and bradykinin (BK1 and BK2) receptor antagonists, cannabinoids, blockers of Na+-dependent channels and large conductance Ca+2-dependent K+-channel activators. Specific agents include dexbrompheniramine plus pseudoephedrine, loratadine, oxymetazoline, ipratropium, albuterol, beclomethasone, morphine, codeine, pholcodeine and dextromethorphan. The present invention further provides combination therapy for the treatment of urinary incontinence. Within such aspects, a VR1 modulator provided herein may be used in combination with other medication designed to treat this condition, such as estrogen replacement therapy, progesterone congeners, electrical stimulation, calcium channel blockers, antispasmodic agents, cholinergic antagonists, antimuscarinic drugs, tricyclic antidepressants, SNRIs, beta adrenoceptor agonists, phosphodiesterase inhibitors, potassium channel openers, nociceptin/orphanin FQ (OP4) agonists, neurokinin (NK1 and NK2) antagonists, P2X3 antagonists, musculotrophic drugs and sacral neuromodulation. Specific agents include oxybutinin, emepronium, tolterodine, flavoxate, flurbiprofen, tolterodine, dicyclomine, propiverine, propantheline, dicyclomine, imipramine, doxepin, duloxetine, 1-deamino-8-D-arginine vasopressin, muscarinic receptor antagonists such as tolterodine and anticholinergic agents such as oxybutynin. Suitable dosages for VR1 modulator within such combination therapy are generally as described above. Dosages and methods of administration of other pain relief medications can be found, for example, in the manufacturer's instructions in the Physician's Desk Reference. In certain embodiments, the combination administration of a VR1 modulator with one or more additional pain medications results in a reduction of the dosage of each therapeutic agent required to produce a therapeutic effect (e.g., the dosage or one or both agent may less than ¾, less than ½, less than ¼ or less than 10% of the maximum dose listed above or advised by the manufacturer). For use in combination therapy, pharmaceutical compositions as described above may further comprise one or more additional medications as described above. In certain such compositions, the additional medication is an analgesic. Also provided herein are packaged pharmaceutical preparations comprising one or more VR1 modulators and one or more additional medications (e.g., analgesics) in the same package. Such packaged pharmaceutical preparations generally include (i) a container holding a pharmaceutical composition that comprises at least one VR1 modulator as described herein; (ii) a container holding a pharmaceutical composition that comprises at least one additional medication (such as a pain relief and/or anti-inflammatory medication) as described above and (iii) instructions (e.g., labeling or a package insert) indicating that the compositions are to be used simultaneously, separately or sequentially for treating or preventing a condition responsive to VR1 modulation in the patient (such as a condition in which pain and/or inflammation predominates). Compounds that are VR1 agonists may further be used, for example, in crowd control (as a substitute for tear gas) or personal protection (e.g., in a spray formulation) or as pharmaceutical agents for the treatment of pain, itch, menopause symptoms, urinary incontinence or overactive bladder via capsaicin receptor desensitization. In general, compounds for use in crowd control or personal protection are formulated and used according to conventional tear gas or pepper spray technology. Within separate aspects, the present invention provides a variety of non-pharmaceutical in vitro and in vivo uses for the compounds provided herein. For example, such compounds may be labeled and used as probes for the detection and localization of capsaicin receptor (in samples such as cell preparations or tissue sections, preparations or fractions thereof). In addition, compounds provided herein that comprise a suitable reactive group (such as an aryl carbonyl, nitro or azide group) may be used in photoaffinity labeling studies of receptor binding sites. In addition, compounds provided herein may be used as positive controls in assays for receptor activity, as standards for determining the ability of a candidate agent to bind to capsaicin receptor, or as radiotracers for positron emission tomography (PET) imaging or for single photon emission computerized tomography (SPECT). Such methods can be used to characterize capsaicin receptors in living subjects. For example, a VR1 modulator may be labeled using any of a variety of well known techniques (e.g., radiolabeled with a radionuclide such as tritium, as described herein), and incubated with a sample for a suitable incubation time (e.g., determined by first assaying a time course of binding). Following incubation, unbound compound is removed (e.g., by washing), and bound compound detected using any method suitable for the label employed (e.g., autoradiography or scintillation counting for radiolabeled compounds; spectroscopic methods may be used to detect luminescent groups and fluorescent groups). As a control, a matched sample containing labeled compound and a greater (e.g., 10-fold greater) amount of unlabeled compound may be processed in the same manner. A greater amount of detectable label remaining in the test sample than in the control indicates the presence of capsaicin receptor in the sample. Detection assays, including receptor autoradiography (receptor mapping) of capsaicin receptor in cultured cells or tissue samples may be performed as described by Kuhar in sections 8.1.1 to 8.1.9 of Current Protocols in Pharmacology (1998) John Wiley & Sons, New York. Compounds provided herein may also be used within a variety of well known cell separation methods. For example, modulators may be linked to the interior surface of a tissue culture plate or other support, for use as affinity ligands for immobilizing and thereby isolating, capsaicin receptors (e.g., isolating receptor-expressing cells) in vitro. Within one preferred embodiment, a modulator linked to a fluorescent marker, such as fluorescein, is contacted with the cells, which are then analyzed (or isolated) by fluorescence activated cell sorting (FACS). VR1 modulators provided herein may further be used within assays for the identification of other agents that bind to capsaicin receptor. In general, such assays are standard competition binding assays, in which bound, labeled VR1 modulator is displaced by a test compound. Briefly, such assays are performed by: (a) contacting capsaicin receptor with a radiolabeled VR1 modulator as described herein, under conditions that permit binding of the VR1 modulator to capsaicin receptor, thereby generating bound, labeled VR1 modulator; (b) detecting a signal that corresponds to the amount of bound, labeled VR1 modulator in the absence of test agent; (c) contacting the bound, labeled VR1 modulator with a test agent; (d) detecting a signal that corresponds to the amount of bound labeled VR1 modulator in the presence of test agent; and (e) detecting a decrease in signal detected in step (d), as compared to the signal detected in step (b). The following Examples are offered by way of illustration and not by way of limitation. Unless otherwise specified all reagents and solvent are of standard commercial grade and are used without further purification. Using routine modifications, the starting materials may be varied and additional steps employed to produce other compounds provided herein. EXAMPLES Mass Spectroscopy data provide in the following examples is Electrospray MS, obtained in positive ion mode with a 15V or 30V cone voltage, using a Micromass Time-of-Flight LCT, equipped with a Waters 600 pump, Waters 996 photodiode array detector, Gilson 215 autosampler, and a Gilson 841 microinjector. MassLynx (Advanced Chemistry Development, Inc; Toronto, Canada) version 4.0 software is used for data collection and analysis. Sample volume of 1 microliter is injected onto a 50×4.6 mm Chromolith SpeedROD C18 column, and eluted using a 2-phase linear gradient at 6 ml/min flow rate. Sample is detected using total absorbance count over the 220-340 nm UV range. The elution conditions are: Mobile Phase A-95/5/0.05 Water/Methanol/TFA; Mobile Phase B-5/95/0.025 Water/Methanol/TFA. Gradient: Time (min) % B 0 10 0.5 100 1.2 100 1.21 10 The total run time is 2 minutes inject to inject. Example 1 Preparation of Representative Intermediates This Example illustrates the preparation of representative intermediates useful in the synthesis of 2-phenoxy pyrimidinone derivatives. A. Ethyl 3-nitriloalaninate A mixture of ethyl cyanoglyoxylate-2-oxime (50 g, 352 mmol) in 440 mL of water is cautiously treated with 340 mL of saturated aqueous NaHCO3, followed by portionwise addition of sodium hydrosulfite (165 g, 950 mmol). The reaction is then heated to an internal temperature of 35° C. for 35 min. After cooling to RT, the reaction is saturated with NaCl (approx. 250 g) and extracted with CH2Cl2 (6×150 mL). The combined CH2Cl2 extracts are dried (Na2SO4), filtered, and concentrated in vacuo to give the title compound as a brown oil. 1H NMR (400 MHz, CDCl3) δ 4.43 (1H, s), 4.34 (2H, q, J 7.2), 2.30 (2H, bs), 1.35 (3H, t, J 7.2). B. Ethyl 5-amino-1-methyl-1H-imidazole-4-carboxylate A mixture of ethyl 3-nitriloalaninate (26.7 g, 208 mmol) and triethyl orthoformate (34.6 mL, 208 mmol) in 340 mL of acetonitrile is heated to 90° C. and stirred for 70 min. After cooling to RT, methylamine (25.9 mL of a 33 wt % solution in EtOH, 208 mmol) is added, followed by 20 h of stirring at RT. The reaction mixture is then concentrated in vacuo and dissolved in approx. 200 mL of 1N HCl. The aqueous solution is washed with CH2Cl2 (3×100 mL), basified to pH=9-10 with solid NaHCO3, and extracted with CH2Cl2 (5×100 mL). The combined CH2Cl2 extracts are dried (Na2SO4), filtered, and concentrated to give a brown solid. The solid is slurried in EtOAc, filtered, and washed with Et2O to give the title compound as an off-white solid. 1H NMR (400 MHz, CDCl3) δ 7.03 (1H, s), 4.88 (2H, bs), 4.33 (2H, q, J 7.2), 3.45 (3H, s), 1.37 (3H, t, J 7.2). C. 1-(4-Fluorophenyl)-9-methyl-2-thioxo-1,2,39-tetrahydro-6H-purin-6-one hydrochloride Ethyl 5-amino-1-methyl-1H-imidazole-4-carboxylate (8.45 g, 0.05 moles) and 4-fluorophenyl isothiocyanate (7.65 g, 0.05 moles) are stirred in pyridine (125 mL) at 45° C. for 20 h. The reaction mixture is concentrated under vacuum and diluted by the addition of ice cold water. The reaction mixture is extracted with CH2Cl2 (2×250 mL), washed with water (200 mL) and dried over MgSO4. The filtrate is evaporated in vacuo to give crude intermediate as red orange viscous oil. The oil is slurried in 1% aqueous sodium hydroxide solution (300 mL) and heated at 90° C. for 20 h. The reaction mixture is cooled and the solid is filtered. The filtrate is evaporated in vacuo to reduced volume (100 mL). The mixture is acidified using concentrated HCl to pH 4.0 and allowed stand at RT overnight. The yellow solid which separates is filtered and dried at 70° C., to afford the title compound. 1H NMR (400 MHz, DMSO-d6) δ 7.8 (1H, s), 7.2-7.4 (4H, m), 3.74 (3H, s). D. 2-Chloro-1-(4-fluorophenyl)-9-ethyl-1,9-dihydro-6H-purin-6-one 1-(4-Fluorophenyl)-9-methyl-2-thioxo-1,2,3,9-tetrahydro-6H-purin-6-one hydrochloride (6.5 g, 0.021 mol) is suspended in a large excess of phosphorous oxychloride (150 mL) and heated to 135° C. for 40 h. The reaction mixture is cooled, evaporated in vacuo, and azeotroped twice with toluene. The resulting sticky brown oil is dissolved in DCM (200 mL) then neutralized with saturated NaHCO3 (aqueous). The aqueous layer is extracted with DCM (2×200 mL) and dried (MgSO4). The dried extract is filtered and concentrated under vacuum to afford crude product as a light brown solid. The crude product is purified by flash column chromatography using 1-2.5% MeOH/CH2Cl2 to afford the title compound as white solid. 1H NMR (400 MHz, CDCl3) δ 7.75 (1H, s), 7.2-7.35 (4H, m), 3.85 (3H, s). E. Ethyl 3-aminopyridine-2-carboxylate A mixture of 3-aminopyridine-2-carboxylic acid (6.4 g, 46.3 mmol) in 26 mL of EtOH and 8 mL of concentrated sulfuric acid is heated to reflux for 2 days. After cooling, the mixture is concentrated to about 15-20 mL and poured into 20 g of ice. The mixture is basified to pH 8-9 with concentrated NH4OH while cooling in an ice bath. The resulting brown precipitate is filtered off, and the filtrate is extracted with ether (4×60 mL). The combined ether extracts are washed with brine (4×60 mL), dried (Na2SO4), filtered, and evaporated to give a yellow/brown solid. This solid is combined with that from the above filtration and the whole is triturated with cold ether to give the title compound as a light brown solid. 1H NMR (400 MHz, CDCl3) δ 8.08 (1H, m), 7.21 (1H, m), 7.03 (1H, m), 5.74 (2H, bs), 4.44 (2H, q, J 7.2, 6.9), 1.45 (3H, t, J 6.9). F. 3-(4-Fluorophenyl)-2-thioxo-2,3-dihydropyrido[3,2-d]pyrimidin-4(1H)-one A mixture of ethyl 3-aminopyridine-2-carboxylate (2.0 g, 12.0 mmol) and 4-fluorophenylisothiocyanate (1.84 g, 12.0 mmol) in 7 mL of anhydrous pyridine is stirred at 45° C. for 21 h. After cooling, the pyridine is evaporated in vacuo, and ice water is added to the residue. The resulting mixture is slurried in EtOAc and filtered to give the title compound as a white solid. 1H NMR (400 MHz, DMSO-d6) δ 8.59 (1H, m), 7.79 (2H, m), 7.33 (4H, m). G. 2-Chloro-3-(4-fluorophenyl)pyrido[3,2-d]pyrimidin-4(3H)-one A mixture of 3-(4-fluorophenyl)-2-thioxo-2,3-dihydropyrido[3,2-d]pyrimidin-4(1H)-one (2.6 g, 9.5 mmol) in 30 mL of POCl3 is heated to 135° C. and stirred for 2 days. After cooling to RT, the excess POCl3 is removed in vacuo, and the residue is azeotroped twice with toluene. The resulting sticky brown oil/solid mix is dissolved in CH2Cl2 and neutralized to pH 7-8 with saturated NaHCO3. The layers are separated, and the CH2Cl2 layer is dried (Na2SO4), filtered, and evaporated to give a brown sticky solid. Purification by column chromatography (gradient from CH2Cl2 to 20% EtOAc/CH2Cl2) affords the title compound as an off-white solid. 1H NMR (400 MHz, CDCl3) δ 8.91 (1H, m), 8.05 (11H, m), 7.74 (1H, m), 7.28 (4H, m). H. Acetic Formic Anhydride Acetic anhydride (35.94 g, 352 mmol) and formic acid (16.20 g, 352 mmol) are added to a round bottomed flask, and heated at 55° C. for 3 h. The reaction mixture is used in Example 11 without further purification. I. Ethyl N-formyl-3-nitriloalaninate Ethyl 3-nitriloalaninate (26.9 g, 210 mmol) is dissolved in anhydrous ether (200 mL), and cooled in an ice/water bath. Acetic formic anhydride (prepared as a mixture as described above) is added dropwise. When the addition is finished, the reaction mixture is allowed to warm to RT and stirred at RT overnight. Most volatiles are removed in vacuo, and the residue solvents are removed by co-evaporation with toluene (100 mL×4). The red oil obtained precipitates upon scratching in ether, and the resulting solids are recrystallized in ether to give the title compound as a white solid. 1H NMR (400 MHz, CDCl3) 8.32 (1H, s), 7.26 (1H, s), 6.46 (1H, bs,), 5.56 (1H, d, J 7.8), 4.39 (2H, q), 1.37 (3H, t). J. Ethyl 5-amino-1,3-thiazole-4-carboxylate Ethyl N-formyl-3-nitriloalaninate (11.22 g, 71.86 mmol) is dissolved in anhydrous benzene (220 mL). Following the addition of Lawesson's reagent (14.53 g, 35.93 mmol), the suspension is refluxed for 24 h. Most of the solvent is removed in vacuo, and the viscous red residue is absorbed on silica gel and loaded to a silica gel column (elution solvent: EtOAc:hexanes=50:50). The title compound is obtained as yellow solids. 1H NMR (400 MHz, CDCl3) 7.87 (1H, s), 7.26 (1H, s), 6.01 (2H, broad s), 4.38 (2H, q), 1.41 (3H, t). K. 6-(4-Fluorophenyl)-5-mercapto[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one hydrochloride Ethyl 5-amino-1,3-thiazole-4-carboxylate (1.05 g, 6.10 mmol) and 4-fluorophenyl isothiocyanate (0.93 g, 6.10 mmol) are added to pyridine (3.5 mL) and heated at 45° C. for 15 h. Most of the solvent is removed under vacuum, and the resulting yellow solids are dissolved in CH2Cl2 (150 mL) and washed with H2O (20 mL×2) and brine (20 mL×2). The CH2Cl2 phase is dried over MgSO4, and the solvent is removed under reduced pressure. The resulting residue is treated with 1% NaOH solution (37 mL) and heated at 90° C. for 15 h. The reaction mixture is filtered and the filtrate adjusted to pH 3 by the addition of concentrated HCl. Most of the water is removed under vacuum and the yellow solid which separates is filtered and dried to give the title compound as a yellow solid. 1H NMR (400 MHz, DMSO-d6) 8.90 (1H, s), 7.31 (4H, m). L. 5-Chloro-6-(4-fluorophenyl)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 6-(4-Fluorophenyl)-5-mercapto[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one hydrochloride (0.2 g, 0.633 mmol) is added to POCl3 (10 mL), and the resulting solution is refluxed at 135° C. for 41 h. Most of the volatiles are removed under reduced pressure and the residual solvent is co-evaporated with toluene (50 mL×3). The dark solid obtained is dissolved in CH2Cl2 (200 mL) and washed with saturated NaHCO3 solution (100 mL×5), brine (50 mL×2), and dried over MgSO4. After removing solvent, silica gel column chromatography (EtOAc:hexanes=50:50) yields the title compound as a yellow solid. 1H NMR (400 MHz, CDCl3) 8.88 (1H, s), 7.26 (4H, m). M. 1-(4-Bromophenyl)-2-mercapto-9-methyl-1,9-dihydro-6H-purin-6-one hydrochloride Ethyl 5-amino-1-methyl-1H-imidazole-4-carboxylate (3.50 g, 20.69 mmol) and 4-bromophenyl isothiocyanate (4.43 g, 20.69 mmol) are added to pyridine (12 mL). The solution is heated at 45° C. for 3 h. Most of the solvent is removed under vacuum and the resulting solid is dissolved in CH2Cl2 (300 mL). The CH2Cl2 solution is washed with water (30 mL×2), brine (30 mL×2), dried over MgSO4, and concentrated in vacuo. The resulting yellow solid is treated with 1% NaOH aqueous solution (125 mL) and heated at 90° C. for 18 h. The reaction mixture is filtered and the filtrate adjusted pH to 3 by the addition of concentrated HCl. Most of the water is removed under reduced pressure. The resulting solid is collected by filtration, the solid is azeotroped with toluene (30 mL×3) to give the title compound as a yellow solid. 1H NMR (400 MHz, CD3OD) 8.10 (1H, s), 7.65 (2H, d), 7.14 (2H, d), 3.85 (3H, s). N. 1-(4-Bromophenyl)-2-chloro-9-methyl-1,9-dihydro-6H-purin-6-one 1-(4-Bromophenyl)-2-mercapto-9-methyl-1,9-dihydro-6H-purin-6-one hydrochloride (2.05 g, 5.49 mmol) is added to POCl3 (87 mL) and the resulting solution is refluxed at 135° C. for 38 h. Most volatiles are removed under vacuum and the residual solvents are co-evaporated with toluene (50 mL×3). The resulting dark solid is dissolved in CH2Cl2 (300 mL), washed with saturated NaHCO3 solution (100 mL×5), brine (50 mL×2), and dried over MgSO4. After removing solvent in vacuo, silica gel column chromatography (EtOAc:hexanes=50:50) gives the title compound as a yellow solid. 1H NMR (400 MHz, CDCl3) 7.51 (1H, s), 7.67 (2H, d), 7; 14 (2H, d), 3.83 (3H, s); m/z (ES+) 340.90 (M+). Example 2 Synthesis of Representative 2-Phenoxy Pyrimidinone Derivatives A. 1-(4-Bromophenyl)-9-methyl-2-(2,3,4-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one (Compound 1) 1-(4-Bromophenyl)-2-chloro-9-methyl-1,9-dihydro-6H-purin-6-one (150 mg, 0.4417 mmol) and 2,3,4-trifluorophenol (130.8 mg, 0.8834 mmol) are added to a vial, and the sealed mixture is heated with stirring at 140° C. for 23 h. Silica gel column chromatography (MeOH:CH2Cl2=0.5:99.5) gives the title compound as a white solid. 1H NMR (400 MHz, CDCl3) 7.66 (3H, m), 7.24 (2H, m), 7.00 (2H, m), 3.58 (3H, s). MS (M+1): 451.08; RT=1.31 min. The IC50 determined as described in Example 6 is 100 nanomolar or less. B. 1-(4-Fluorophenyl)-9-methyl-2-(3,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one (Compound 2) A mixture of 2-chloro-1-(4-fluorophenyl)-9-ethyl-1,9-dihydro-6H-purin-6-one (55.6 mg, 0.20 mmol) and 3,4,5-trifluorophenol (0.40 mmol) is heated to 140° C. for 36 h. After cooling to RT, the crude mixture is purified by preparative HPLC to give the title compound as a white solid. 1H NMR (400 MHz, DMSO-d6) 7.98 (1H, s), 7.55 (2H, m), 7.45 (2H, m), 7.34 (2H, m), 3.53 (3H, S). m/z=391.05 (M+1); RT=0.78 min. C. 3-(4-Fluorophenyl)-2-[2-fluoro-3-(trifluoromethyl)phenoxy]pyrido[3,2-d]pyrimidin-4(3H)-one (Compound 3) A mixture of 2-chloro-3-(4-fluorophenyl)pyrido[3,2-d]pyrimidin-4(3H)-one (55 mg, 0.20 mmol) and 2-fluoro-3-trifluoromethylphenol (50 μl, 0.40 mmol) is heated to 140° C. for 18 hours. After cooling to RT, the crude mixture is purified by column chromatography (gradient from CH2Cl2 to 20% EtOAc/CH2Cl2) to give the title compound as a white solid. 1H NMR (400 MHz, DMSO-d6) 8.71 (1H, m), 7.83 (2H, m), 7.70 (4H, m), 7.45 (3H, m). MS (M+1): 420.07; RT=1.13 min. D. 5-(2,4-Difluorophenoxy)-6-(4-fluorophenyl)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one (Compound 4) 5-Chloro-6-(4-fluorophenyl)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one (0.2 mmol) and 2.4-difluorophenol (0.4 mmol) are added to a vial, and the sealed mixture is heated with stirring at 140° C. for 48 h. Silica gel column chromatography (MeOH:CH2Cl2=0.5:99.5) gives the title compound as a slightly yellow solid. 1H NMR (400 MHz, CDCl3) 8.70 (1H, s), 7.36 (2H, m), 7.26 (2H, m), 7.14 (1H, m), 6.94 (2H, m). MS (M+1): 376.03; RT=1.33 min. E. 4-[9-Methyl-6-oxo-2-(2,3,4-trifluorophenoxy)-6,9-dihydro-1H-purin-1-yl]benzonitrile (Compound 5) 1-(4-Bromophenyl)-9-methyl-2-(2,3,4-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one (68 mg, 0.1507 mmol), Zn(CN)2 (10.6 mg, 0.0904 mmol), Pd2(dba)3 (4.1 mg, 0.0045 mmol) and 1,1′-bis(diphenylphosphino)ferrocene (5.0 mg, 0.0090 mmol) are added to DMF (1.2 mL) and H2O (0.012 mL). The mixture is purged with N2 for 3 min and then heated at 120° C. for 18 h. The mixture is passed through celite. Water (30 mL) is added and the resulting mixture is extracted with CH2Cl2 (50 mL×4). After drying the CH2Cl2 over MgSO4, the solvent is removed in vacuo. The crude product is purified by column chromatography (MeOH:CH2Cl2=2:98) to afford the title compound as a brown solid. 1H NMR (400 MHz, CDCl3) 7.86 (2H, d, J 8), 7.65 (1H, s), 7.53 (2 h, d, J 8), 6.95 (2H, m), 3.59 (3H, s). MS (M+1): 398.03; RT=1.22 min. F. 1-(6-Chloropyiridin-3-yl)-9-methyl-2-(3,4,5-trifluorophenoxy)-1H-purin-6(9H)-one (Compound 6) Step 1. 2-Hydroxy-1-(6-chloropyridin-3-yl)-1,9-dihydro-6H-purin-6-one Methyl 5-amino-1-methyl-1H-imidazole-4-carboxylate (1.0 g, 0.006 moles), 2-chloro-5-isocyantopyridine (1.0 g, 0.006 moles) and DMAP (0.4 g, 0.003 mole) are suspended in EtOAc (150 mL) and the resulting reaction mixture is refluxed overnight. The reaction mixture is filtered, washed with EtOAc, and concentrated under vacuum. The white residue is suspended in 1% aqueous NaOH (53 mL) and stirred at 90° C. for 20 h. The reaction mixture is neutralized with 6N HCl and extracted with DCM to afford the title compound. Step 2. 2-Chloro-1-(6-chloropyridin-3-yl)-1,9-dihydro-6H-purin-6-one 2-Hydroxy-1-(6-chloropyridin-3-yl)-1,9-dihydro-6H-purin-6-one from the above reaction is suspended in a large excess of phosphorous oxychloride (150 mL) and heated to 135° C. for 24 h. The reaction mixture is cooled, evaporated in vacuo, and additional toluene is added and evaporated (2×) under reduced pressure. The resulting sticky brown oil is dissolved in DCM (200 mL), and then neutralized with saturated NaHCO3 (aqueous). The aqueous layer is extracted with DCM (2×200 mL) and dried (MgSO4). The dried extract is filtered and concentrated under vacuum to afford crude product as a light brown solid. The crude product is purified by flash column chromatography using 1-2.5% MeOH/CH2Cl2 to afford the title compound as white solid. 1H NMR (300 MHz, CDCl3) δ 8.33 (s, 1H), 7.78 (s, 1H), 7.58 (d, J=6 Hz, 1H), 7.53 (d, J=6 Hz, 1H). Step 3. 1-(6-chloropyridin-3-yl)-9-methyl-2-(3,4,5-trifluorophenoxy)-1H-purin-6(9H)-one (Compound 6) 1.0 M KOtBu in isopropanol (2 mL) is added to the solution of 3,4,5-trifluorophenol (0.29 g, 1.86 mmol) and stirred for 20 minutes at RT. To the resulting phenoxide solution is added a solution of 2-chloro-1-(6-chloropyridin-3-yl)-1,9-dihydro-6H-purin-6-one (0.5 g, 1.69 mmol) in dimethylacetamide (3 mL) and the resulting mixture is stirred overnight at 50° C. The resulting reaction mixture is cooled, quenched with saturated NH4Cl solution, extracted with DCM (2×50 mL) and dried (Na2SO4). The organic layer is filtered and concentrated under vacuum to afford the crude product as a light brown solid. The crude product is further purified by flash column chromatography using 5% MeOH/CH2Cl2 to afford the title compound as white solid. 1H NMR (300 MHz, CDCl3) δ 8.41 (s, 1H), 7.55-7.81 (m, 2H), 7.4 (brs, 1H), 6.71-7.02 (m, 2H), 3.85 (s, 3H). MS (M+1): 408.04; RT=1.48 min. The IC50 determined as described in Example 6 is 100 nanomolar or less. G. 5-(9-Methyl-6-oxo-2-(3,4,5-trifluorophenoxy)-6H-purin-1(9H)-yl)picolinonitrile (Compound 7) 1-(6-chloropyridin-3-yl)-9-methyl-2-(3,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one (0.3 g, 0.73 mmol), Zn(CN)2 (0.43 mg, 3.65 mmol), Pd2(dba)3 (0.07 g, 0.073 mmol) and DPPF (0.04 g, 0.073 mmol) are added to DMF (3 mL). The mixture is purged with N2 for 3 min and then heated at 120° C. for 18 h. Water (20 mL) is added and the resulting mixture is extracted with DCM (2×20 mL). The organic layer is passed through celite and Na2SO4 and the solvent is removed in vacuo. The crude product is purified by column chromatography on silica gel (MeOH:CH2Cl2=2:98) to afford the title compound as a white solid. 1H NMR (300 MHz, CDCl3) δ 8.71 (s, 1H), 7.90 (s, 2H), 7.68 (s, 1H), 7.25 (s, 2H), 6.85-6.89 (m, 2H), 3.65 (s, 3H, s). MS (M+1): 399.07; RT=1.41 min. The IC50 determined as described in Example 6 is 100 nanomolar or less. Example 3 Additional Representative 2-Phenoxy Pyrimidinone Derivatives Using routine modifications, the starting materials may be varied and additional steps employed to produce other compounds provided herein. Compounds listed in Table I are prepared using such methods. In the column labeled “IC50” a * indicates that the IC50 determined as described in Example 6 is 100 nanomolar or less (i.e., the concentration of such compounds that is required to provide a 50% decrease in the fluorescence response of cells exposed to one IC50 of capsaicin is 100 nanomolar or less). Mass spectroscopy data obtained as described above is presented as M+1 in the column headed “MS”, and retention times are provided in the column headed “RT,” in minutes. TABLE I Representative 2-Phenoxy Pyrimidinone Derivatives Compound Name MS RT IC50 8 1-(4-chlorophenyl)-9-methyl-2-(2,4,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 406.99 1.27 * 9 9-ethyl-1-(4-fluorophenyl)-2-(2,4,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 405.03 1.25 * 10 1-(4-chlorophenyl)-9-methyl-2-(2,3,4-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 407.00 1.28 * 11 9-ethyl-1-(4-fluorophenyl)-2-(2,3,4-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 405.04 1.26 * 12 1-(4-fluorophenyl)-9-methyl-2-(2,4,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 391.03 1.23 * 13 1-(4-fluorophenyl)-9-methyl-2-(2,3,4-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 391.04 1.24 * 14 1-(4-chlorophenyl)-2-(2,4-difluorophenoxy)-9-methyl-1,9-dihydro-6H-purin-6-one 389.01 1.25 * 15 2-(2,4-difluorophenoxy)-9-ethyl-1-(4-fluorophenyl)-1,9-dihydro-6H-purin-6-one 387.06 1.24 * 16 2-(2,4-difluorophenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one 373.03 1.22 * 17 2-(2,3-difluorophenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one 373.05 1.22 * 18 2-(2,3-difluorophenoxy)-9-ethyl-1-(4-fluorophenyl)-1,9-dihydro-6H-purin-6-one 387.05 1.24 * 19 2-(4-chloro-2-fluorophenoxy)-9-ethyl-1-(4-fluorophenyl)-1,9-dihydro-6H-purin-6-one 403.00 1.28 * 13 2-(4-chloro-2-fluorophenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one 389.00 1.26 * 14 2-(4-chloro-2-fluorophenoxy)-1-(4-chlorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one 404.96 1.3 * 15 1-(4-fluorophenyl)-9-methyl-2-(2,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 391.07 1.18 * 16 9-ethyl-1-(4-fluorophenyl)-2-(2,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 405.09 1.11 * 17 1-(4-chlorophenyl)-9-methyl-2-(2,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 407.04 1.3 18 2-(2,3-difluoro-4-methoxyphenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one 403.09 0.89 * 19 2-(2,3-difluoro-4-methoxyphenoxy)-9-ethyl-1-(4-fluorophenyl)-1,9-dihydro-6H-purin-6-one 417.11 0.56 * 20 1-(4,fluorophenyl)-9-methyl-2-(2,3,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 391.07 1.21 * 21 1-(4-chlorophenyl)-2-(2,3-difluorophenoxy)-9-methyl-1,9-dihydro-6H-purin-6-one 389.05 1.26 * 22 2-(2-chloro-4-fluorophenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one 389.05 1.22 * 23 2-(2-chloro-4-fluorophenoxy)-1-(4-chlorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one 405.02 0.6 * 24 1-(4-fluorophenyl)-9-methyl-2-(2,3,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 391.07 1.18 * 25 1-(4-chlorophenyl)-9-methyl-2-(2,3,6-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 407.04 0.62 * 26 9-ethyl-1-(4-fluorophenyl)-2-(2,3,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 405.09 0.72 * 27 1-(4-chlorophenyl)-9-methyl-2-(2,3,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 407.04 0.69 * 28 4-{[1-(4-chlorophenyl)-9-methyl-6-oxo-6,9-dihydro-1H-purin-2-yl]oxy}-2,3-difluorobenzonitrile 414.06 1.25 * 29 2,3-difluoro-4-{[1-(4-fluorophenyl)-9-methyl-6-oxo-6,9-dihydro-1H-purin-2-yl]oxy}benzonitrile 398.07 1.22 * 30 1-(4-chlorophenyl)-9-methyl-2-(3,4,5-trifluorophenoxy)-1,9-dihydro-6H-purin-6-one 407.04 1.39 * 31 2-(2,4-difluorophenoxy)-3-(4-fluorophenyl)pyrido[3,2-d]pyrimidin-4(3H)-one 370.11 1.26 * 32 3-(4-fluorophenyl)-2-(2,3,4-trifluorophenoxy)pyrido[3,2-d]pyrimidin-4(3H)-one 388.09 1.3 * 33 6-(4-fluorophenyl)-5-(2,3,4-trifluorophenoxy)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 394.02 1.39 * 34 5-(2,3-difluorophenoxy)-6-(4-fluorophenyl)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 376.02 1.27 * 35 6-(4-fluorophenyl)-5-(2,4,5-trifluorophenoxy)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 394.02 0.66 * 36 6-(4-fluorophenyl)-5-(2,3,5-trifluorophenoxy)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 394.01 1.29 * 37 6-(4-fluorophenyl)-5-(3,4,5-trifluorophenoxy)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 394.02 1.41 * 38 5-(4-chloro-2-fluorophenoxy)-6-(4-fluorophenyl)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 392.00 1.09 * 39 3-(4-fluorophenyl)-2-[3-(trifluoromethyl)phenoxy]pyrido[3,2-d]pyrimidin-4(3H)-one 402.08 1.44 40 2-[-chloro-3-(trifluoromethyl)phenoxy]-3-(4-fluorophenyl)pyrido[3,2-d]pyrimidin-4(3H)-one 436.04 0.51 41 6-(4-fluorophenyl)-5-[2-fluoro-3-(trifluoromethyl)phenoxy][1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 426.03 0.63 42 1-(4-chlorophenyl)-2-[2-fluoro-3-(trifluoromethyl)phenoxy]-9-methyl-1,9-dihydro-6H-purin-6-one 439.05 0.63 * 43 1-(4-fluorophenyl)-2-[2-fluoro-3-(trifluoromethyl)phenoxy]-9-methyl-1,9-dihydro-6H-purin-6-one 423.08 1.39 * 44 6-(4-fluorophenyl)-5-[3-fluoro-5-(trifluoromethyl)phenoxy][1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 426.03 0.51 * 45 5-[2-chloro-3-(trifluoromethyl)phenoxy]-6-(4-fluorophenyl)[1,3]thiazolo[5,4-d]pyrimidin-7(6H)-one 442.00 0.51 46 6-(4-fluorophenyl)-5-(3-(trifluoromethyl)phenoxy)thiazolo[5,4-d]pyrimidin-7(6H)-one 408.04 1.48 * 47 3-(4-fluorophenyl)-2-[3-fluoro-5-(trifluoromethyl)phenoxy]pyrido[3,2-d]pyrimidin-4(3H)-one 420.07 0.52 48 1-(4-fluorophenyl)-9-methyl-2-[3-(trifluoromethyl)phenoxy]-1,9-dihydro-6H-purin-6-one 405.09 0.54 * 49 1-(4-fluorophenyl)-2-[3-fluoro-5-(trifluoromethyl)phenoxy]-9-methyl-1,9-dihydro-6H-purin-6-one 423.08 1.36 * 50 3-(4-chlorophenyl)-7-methyl-2-(2,3,4-trifluoromethyl)thieno[3,2-d]pyrimidin-4(3H)-one 423.03 1.4 * 51 2-(4-chloro-2-fluorophenoxy)-3-(4-chlorophenyl)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one 421.00 1.41 * 52 3-(4-chlorophenyl)-2-(2,4-difluorophenoxy)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one 405.05 1.37 * 53 3-(4-fluorophenyl)-7-methyl-2-(2,3,4-trifluorophenoxy)thieno[3,2-d]pyrimidin-4(3H)-one 405.07 1.4 * 54 2-(4-chloro-2-fluorophenoxy)-3-(4-fluorophenyl)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one 405.02 0.65 * 55 3-(4-fluorophenyl)-7-methyl-2-(2,3,6-trifluorophenoxy)thieno[3,2-d]pyrimidin-4(3H)-one 407.07 1.36 * 56 3-(4-fluorophenyl)-4-oxo-2-(2,3,4-trifluorophenoxy)-3,4-dihydrothieno[3,2-d]pyrimidine-7-carbonitrile 417.99 1.31 57 3-(4-fluorophenyl)-2-(2-methoxyphenoxy)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one 383.09 1.31 58 3-(4-fluorophenyl)-7-methyl-2-(2-methylphenoxy)thieno[3,2-d]pyrimidin-4(3H)-one 367.09 1.36 59 2-(2-ethylphenoxy)-3-(4-fluorophenyl)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one 381.11 1.38 60 3-(4-fluorophenyl)-2-(2-isopropylphenoxy)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one 395.12 1.39 61 2-(2,3-dimethoxyphenoxy)-3-(4-fluorophenyl)-7-methylthieno[3,2-d]pyrimidin-4(3H)-one 413.09 1.3 62 2-(2,6-dimethylphenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one 365.14 1.28 63 2-(2,3-dimethylphenoxy)-1-(4-fluorophenyl)-9-methyl-1,9-dihydro-6H-purin-6-one 365.13 1.28 * Example 4 VR1-Transfected Cells and Membrane Preparations This Example illustrates the preparation of VR1-transfected cells and VR1-containing membrane preparations for use in capsaicin binding assays (Example 5). A cDNA encoding full length human capsaicin receptor (SEQ ID NO: 1, 2 or 3 of U.S. Pat. No. 6,482,611) is subcloned in the plasmid pBK-CMV (Stratagene, La Jolla, Calif.) for recombinant expression in mammalian cells. Human embryonic kidney (HEK293) cells are transfected with the pBK-CMV expression construct encoding the full length human capsaicin receptor using standard methods. The transfected cells are selected for two weeks in media containing G418 (400 μg/ml) to obtain a pool of stably transfected cells. Independent clones are isolated from this pool by limiting dilution to obtain clonal stable cell lines for use in subsequent experiments. For radioligand binding experiments, cells are seeded in T175 cell culture flasks in media without antibiotics and grown to approximately 90% confluency. The flasks are then washed with PBS and harvested in PBS containing 5 mM EDTA. The cells are pelleted by gentle centrifugation and stored at −80° C. until assayed. Previously frozen cells are disrupted with the aid of a tissue homogenizer in ice-cold HEPES homogenization buffer (5 mM KCl 5, 5.8 mM NaCl, 0.75 mM CaCl2, 2 mM MgCl2, 320 mM sucrose, and 10 mM HEPES pH 7.4). Tissue homogenates are first centrifuged for 10 minutes at 1000×g (4° C.) to remove the nuclear fraction and debris, and then the supernatant from the first centrifugation is further centrifuged for 30 minutes at 35,000×g (4° C.) to obtain a partially purified membrane fraction. Membranes are resuspended in the HEPES homogenization buffer prior to the assay. An aliquot of this membrane homogenate is used to determine protein concentration via the Bradford method (BIO-RAD Protein Assay Kit, #500-0001, BIO-RAD, Hercules, Calif.). Example 5 Capsaicin Receptor Binding Assay This Example illustrates a representative assay of capsaicin receptor binding that may be used to determine the binding affinity of compounds for the capsaicin (VR1) receptor. Binding studies with [3H] Resiniferatoxin (RTX) are carried out essentially as described by Szallasi and Blumberg (1992) J. Pharmacol. Exp. Ter. 262:883-888. In this protocol, non-specific RTX binding is reduced by adding bovine alpha1 acid glycoprotein (100 μg per tube) after the binding reaction has been terminated. [3H] RTX (37 Ci/mmol) is synthesized by and obtained from the Chemical Synthesis and Analysis Laboratory, National Cancer Institute-Frederick Cancer Research and Development Center, Frederick, Md. [3H] RTX may also be obtained from commercial vendors (e.g., Amersham Pharmacia Biotech, Inc.; Piscataway, N.J.). The membrane homogenate of Example 4 is centrifuged as before and resuspended to a protein concentration of 333 μg/ml in homogenization buffer. Binding assay mixtures are set up on ice and contain [3H]RTX (specific activity 2200 mCi/ml), 2 μl non-radioactive test compound, 0.25 mg/ml bovine serum albumin (Cohn fraction V), and 5×104-1×105 VR1-transfected cells. The final volume is adjusted to 500 μl (for competition binding assays) or 1,000 μl (for saturation binding assays) with the ice-cold HEPES homogenization buffer solution (pH 7.4) described above. Non-specific binding is defined as that occurring in the presence of 1 μM non-radioactive RTX (Alexis Corp.; San Diego, Calif.). For saturation binding, [3H]RTX is added in the concentration range of 7-1,000 μM, using 1 to 2 dilutions. Typically 11 concentration points are collected per saturation binding curve. Competition binding assays are performed in the presence of 60 μM [3H]RTX and various concentrations of test compound. The binding reactions are initiated by transferring the assay mixtures into a 37° C. water bath and are terminated following a 60 minute incubation period by cooling the tubes on ice. Membrane-bound RTX is separated from free, as well as any alpha1-acid glycoprotein-bound RTX, by filtration onto WALLAC glass fiber filters (PERKIN-ELMER, Gaithersburg, Md.) which are pre-soaked with 1.0% PEI (polyethyleneimine) for 2 hours prior to use. Filters are allowed to dry overnight then counted in a WALLAC 1205 BETA PLATE counter after addition of WALLAC BETA SCINT scintillation fluid. Equilibrium binding parameters are determined by fitting the allosteric Hill equation to the measured values with the aid of the computer program FIT P (Biosoft, Ferguson, Mo.) as described by Szallasi, et al. (1993) J. Pharmacol. Exp. Ther. 266:678-683. Compounds provided herein generally exhibit Ki values for capsaicin receptor of less than 1 μM, 100 nM, 50 nM, 25 nM, 10 nM, or 1 nM in this assay. Example 6 Calcium Mobilization Assay This Example illustrates representative calcium mobilization assays for use in evaluating test compounds for agonist and antagonist activity. Cells transfected with expression plasmids (as described in Example 4) and thereby expressing human capsaicin receptor are seeded and grown to 70-90% confluency in FALCON black-walled, clear-bottomed 96-well plates (#3904, BECTON-DICKINSON, Franklin Lakes, N.J.). The culture medium is emptied from the 96 well plates and FLUO-3 AM calcium sensitive dye (Molecular Probes, Eugene, Oreg.) is added to each well (dye solution: 1 mg FLUO-3 AM, 440 μL DMSO and 440 μl 20% pluronic acid in DMSO, diluted 1:250 in Krebs-Ringer HEPES (KRH) buffer (25 mM HEPES, 5 mM KCl, 0.96 mM NaH2PO4, 1 mM MgSO4, 2 mM CaCl2, 5 mM glucose, 1 mM probenecid, pH 7.4), 50 μl diluted solution per well). Plates are covered with aluminum foil and incubated at 37° C. for 1-2 hours in an environment containing 5% CO2. After the incubation, the dye is emptied from the plates, and the cells are washed once with KRH buffer, and resuspended in KRH buffer. Determination of Capsaicin EC50 To measure the ability of a test compound to agonize or antagonize a calcium mobilization response in cells expressing capsaicin receptors to capsaicin or other vanilloid agonist, the EC50 of the agonist capsaicin is first determined. An additional 20 μl of KRH buffer and 1 μl DMSO is added to each well of cells, prepared as described above. 100 μl capsaicin in KRH buffer is automatically transferred by the FLIPR instrument to each well. Capsaicin-induced calcium mobilization is monitored using either FLUOROSKAN ASCENT (Labsystems; Franklin, Mass.) or FLIPR (fluorometric imaging plate reader system; Molecular Devices, Sunnyvale, Calif.) instruments. Data obtained between 30 and 60 seconds after agonist application are used to generate an 8-point concentration response curve, with final capsaicin concentrations of 1 nM to 3 μM. KALEIDAGRAPH software (Synergy Software, Reading, Pa.) is used to fit the data to the equation: y=a*(1/(1+(b/x)c)) to determine the 50% excitatory concentration (EC50) for the response. In this equation, y is the maximum fluorescence signal, x is the concentration of the agonist or antagonist (in this case, capsaicin), a is the Emax, b corresponds to the EC50 value and c is the Hill coefficient. Determination of Agonist Activity Test compounds are dissolved in DMSO, diluted in KRH buffer, and immediately added to cells prepared as described above. 100 nM capsaicin (an approximate EC90 concentration) is also added to cells in the same 96-well plate as a positive control. The final concentration of test compounds in the assay wells is between 0.1 nM and 5 μM. The ability of a test compound to act as an agonist of the capsaicin receptor is determined by measuring the fluorescence response of cells expressing capsaicin receptors elicited by the compound as function of compound concentration. This data is fit as described above to obtain the EC50, which is generally less than 1 micromolar, preferably less than 100 nM, and more preferably less than 10 nM. The extent of efficacy of each test compound is also determined by calculating the response elicited by a concentration of test compound (typically 1 μM) relative to the response elicited by 100 mM capsaicin. This value, called Percent of Signal (POS), is calculated by the following equation: POS=100*test compound response/100 nM capsaicin response This analysis provides quantitative assessment of both the potency and efficacy of test compounds as human capsaicin receptor agonists. Agonists of the human capsaicin receptor generally elicit detectable responses at concentrations less than 100 μM, or preferably at concentrations less than 1 μM, or most preferably at concentrations less than 10 nM. Extent of efficacy at human capsaicin receptor is preferably greater than 30 POS, more preferably greater than 80 POS at a concentration of 1 μM. Certain agonists are essentially free of antagonist activity as demonstrated by the absence of detectable antagonist activity in the assay described below at compound concentrations below 4 nM, more preferably at concentrations below 10 μM and most preferably at concentrations less than or equal to 100 μM. Determination of Antagonist Activity Test compounds are dissolved in DMSO, diluted in 20 μl KRH buffer so that the final concentration of test compounds in the assay well is between 1 μM and 5 μM, and added to cells prepared as described above. The 96 well plates containing prepared cells and test compounds are incubated in the dark, at room temperature for 0.5 to 6 hours. It is important that the incubation not continue beyond 6 hours. Just prior to determining the fluorescence response, 100 μl capsaicin in KRH buffer at twice the EC50 concentration determined as described above is automatically added by the FLIPR instrument to each well of the 96 well plate for a final sample volume of 200 μl and a final capsaicin concentration equal to the EC50. The final concentration of test compounds in the assay wells is between 1 μM and 5 μM. Antagonists of the capsaicin receptor decrease this response by at least about 20%, preferably by at least about 50%, and most preferably by at least 80%, as compared to matched control (i.e., cells treated with capsaicin at twice the EC50 concentration in the absence of test compound), at a concentration of 10 micromolar or less, preferably 1 micromolar or less. The concentration of antagonist required to provide a 50% decrease, relative to the response observed in the presence of capsaicin and without antagonist, is the IC50 for the antagonist, and is preferably below 1 micromolar, 100 nanomolar, 10 nanomolar or 1 nanomolar. The data is analyzed as follows. First, the average maximum relative fluorescent unit (RFU) response from the negative control wells (no agonist) is subtracted from the maximum response detected for each of the other experimental wells. Second, average maximum RFU response is calculated for the positive control wells (agonist wells). Then, percent inhibition for each compound tested is calculated using the equation: Percent Inhibition=100−100×(Peak Signal in Test Cells/Peak Signal in Control Cells) The % inhibition data is plotted as a function of test compound concentration and test compound IC50 is determined using, for example, KALEIDAGRAPH software (Synergy Software, Reading, Pa.) best fit of the data to the equation: y=m1*(1/(1+(m2/m0)m3)) where y is the percent inhibition, m0 is the concentration of the agonist, m1 is the maximum RFU, m2 corresponds to the test compound IC50 (the concentration required to provide a 50% decrease, relative to the response observed in the presence of agonist and without antagonist) and m3 is the Hill coefficient. Alternatively, test compound IC50 is determined using a linear regression in which x is ln(concentration of test compound) and y is ln(percent inhibition/(100−percent inhibition). Data with a percent inhibition that is greater than 90% or less than 15% are rejected and are not used in the regression. The IC50 calculated in this fashion is e(-intercept/slope) Certain preferred VR1 modulators are antagonists that are essentially free of agonist activity as demonstrated by the absence of detectable agonist activity in the assay described above at compound concentrations below 4 nM, more preferably at concentrations below 10 μM and most preferably at concentrations less than or equal to 100 μM. Example 7 Dorsal Root Ganglion Cell Assay This Example illustrates a representative dorsal root ganglian cell assay for evaluating VR1 antagonist or agonist activity of a compound. DRG are dissected from neonatal rats, dissociated and cultured using standard methods (Aguayo and White (1992) Brain Research 570:61-67). After 48 hour incubation, cells are washed once and incubated for 30-60 minutes with the calcium sensitive dye Fluo 4 AM (2.5-10 ug/ml; TefLabs, Austin, Tex.). Cells are then washed once. Addition of capsaicin to the cells results in a VR1-dependent increase in intracellular calcium levels which is monitored by a change in Fluo-4 fluorescence with a fluorometer. Data are collected for 60-180 seconds to determine the maximum fluorescent signal. For antagonist assays, various concentrations of compound are added to the cells. Fluorescent signal is then plotted as a function of compound concentration to identify the concentration required to achieve a 50% inhibition of the capsaicin-activated response, or IC50. Antagonists of the capsaicin receptor preferably have an IC50 below 1 micromolar, 100 nanomolar, 10 nanomolar or 1 nanomolar. For agonist assays, various concentrations of compound are added to the cells without the addition of capsaicin. Compounds that are capsaicin receptor agonists result in a VR1-dependent increase in intracellular calcium levels which is monitored by a change in Fluo-4 fluorescence with a fluorometer. The EC50, or concentration required to achieve 50% of the maximum signal for a capsaicin-activated response, is preferably below 1 micromolar, below 100 nanomolar or below 10 nanomolar. Example 8 Animal Models for Determining Pain Relief This Example illustrates representative methods for assessing the degree of pain relief provided by a compound. A. Pain Relief Testing The following methods may be used to assess pain relief. Mechanical Allodynia Mechanical allodynia (an abnormal response to an innocuous stimulus) is assessed essentially as described by Chaplan et al. (1994) J. Neurosci. Methods 53:55-63 and Tal and Eliav (1998) Pain 64(3):511-518. A series of von Frey filaments of varying rigidity (typically 8-14 filaments in a series) are applied to the plantar surface of the hind paw with just enough force to bend the filament. The filaments are held in this position for no more than three seconds or until a positive allodynic response is displayed by the rat. A positive allodynic response consists of lifting the affected paw followed immediately by licking or shaking of the paw. The order and frequency with which the individual filaments are applied are determined by using Dixon up-down method. Testing is initiated with the middle hair of the series with subsequent filaments being applied in consecutive fashion, ascending or descending, depending on whether a negative or positive response, respectively, is obtained with the initial filament. Compounds are effective in reversing or preventing mechanical allodynia-like symptoms if rats treated with such compounds require stimulation with a Von Frey filament of higher rigidity strength to provoke a positive allodynic response as compared to control untreated or vehicle treated rats. Alternatively, or in addition, testing of an animal in chronic pain may be done before and after compound administration. In such an assay, an effective compound results in an increase in the rigidity of the filament needed to induce a response after treatment, as compared to the filament that induces a response before treatment or in an animal that is also in chronic pain but is left untreated or is treated with vehicle. Test compounds are administered before or after onset of pain. When a test compound is administered after pain onset, testing is performed 10 minutes to three hours after administration. Mechanical Hyperalgesia Mechanical hyperalgesia (an exaggerated response to painful stimulus) is tested essentially as described by Koch et al. (1996) Analgesia 2(3):157-164. Rats are placed in individual compartments of a cage with a warmed, perforated metal floor. Hind paw withdrawal duration (i.e., the amount of time for which the animal holds its paw up before placing it back on the floor) is measured after a mild pinprick to the plantar surface of either hind paw. Compounds produce a reduction in mechanical hyperalgesia if there is a statistically significant decrease in the duration of hindpaw withdrawal. Test compound may be administered before or after onset of pain. For compounds administered after pain onset, testing is performed 10 minutes to three hours after administration. Thermal Hyperalgesia Thermal hyperalgesia (an exaggerated response to noxious thermal stimulus) is measured essentially as described by Hargreaves et al. (1988) Pain. 32(1):77-88. Briefly, a constant radiant heat source is applied the animals' plantar surface of either hind paw. The time to withdrawal (i.e., the amount of time that heat is applied before the animal moves its paw), otherwise described as thermal threshold or latency, determines the animal's hind paw sensitivity to heat. Compounds produce a reduction in thermal hyperalgesia if there is a statistically significant increase in the time to hindpaw withdrawal (i.e., the thermal threshold to response or latency is increased). Test compound may be administered before or after onset of pain. For compounds administered after pain onset, testing is performed 10 minutes to three hours after administration. B. Pain Models Pain may be induced using any of the following methods, to allow testing of analgesic efficacy of a compound. In general, compounds provided herein result in a statistically significant reduction in pain as determined by at least one of the previously described testing methods, using male SD rats and at least one of the following models. Acute Inflammatory Pain Model Acute inflammatory pain is induced using the carrageenan model essentially as described by Field et al. (1997) Br. J. Pharmacol. 121(8):1513-1522. 100-200 μl of 1-2% carrageenan solution is injected into the rats' hind paw. Three to four hours following injection, the animals' sensitivity to thermal and mechanical stimuli is tested using the methods described above. A test compound (0.01 to 50 mg/kg) is administered to the animal, prior to testing, or prior to injection of carrageenan. The compound can be administered orally or through any parenteral route, or topically on the paw. Compounds that relieve pain in this model result in a statistically significant reduction in mechanical allodynia and/or thermal hyperalgesia. Chronic Inflammatory Pain Model Chronic inflammatory pain is induced using one of the following protocols: 1. Essentially as described by Bertorelli et al. (1999) Br. J. Pharmacol. 128(6):1252-1258, and Stein et al. (1998) Pharmacol. Biochem. Behav. 31(2):455-51, 200 μl Complete Freund's Adjuvant (0.1 mg heat killed and dried M. Tuberculosis) is injected to the rats' hind paw: 100 μl into the dorsal surface and 100 μl into the plantar surface. 2. Essentially as described by Abbadie et al. (1994) J Neurosci. 14(10):5865-5871 rats are injected with 150 μl of CFA (1.5 mg) in the tibio-tarsal joint. Prior to injection with CFA in either protocol, an individual baseline sensitivity to mechanical and thermal stimulation of the animals' hind paws is obtained for each experimental animal. Following injection of CFA, rats are tested for thermal hyperalgesia, mechanical allodynia and mechanical hyperalgesia as described above. To verify the development of symptoms, rats are tested on days 5, 6, and 7 following CFA injection. On day 7, animals are treated with a test compound, morphine or vehicle. An oral dose of morphine of 1-5 mg/kg is suitable as positive control. Typically, a dose of 0.01-50 mg/kg of test compound is used. Compounds can be administered as a single bolus prior to testing or once or twice or three times daily, for several days prior to testing. Drugs are administered orally or through any parenteral route, or applied topically to the animal. Results are expressed as Percent Maximum Potential Efficacy (MPE). 0% MPE is defined as analgesic effect of vehicle, 100% MPE is defined as an animal's return to pre-CFA baseline sensitivity. Compounds that relieve pain in this model result in a MPE of at least 30%. Chronic Neuropathic Pain Model Chronic neuropathic pain is induced using the chronic constriction injury (CCl) to the rat's sciatic nerve essentially as described by Bennett and Xie (1988) Pain 33:87-107. Rats are anesthetized (e.g. with an intraperitoneal dose of 50-65 mg/kg pentobarbital with additional doses administered as needed). The lateral aspect of each hind limb is shaved and disinfected. Using aseptic technique, an incision is made on the lateral aspect of the hind limb at the mid thigh level. The biceps femoris is bluntly dissected and the sciatic nerve is exposed. On one hind limb of each animal, four loosely tied ligatures are made around the sciatic nerve approximately 1-2 mm apart. On the other side the sciatic nerve is not ligated and is not manipulated. The muscle is closed with continuous pattern and the skin is closed with wound clips or sutures. Rats are assessed for mechanical allodynia, mechanical hyperalgesia and thermal hyperalgesia as described above. Compounds that relieve pain in this model result in a statistically significant reduction in mechanical allodynia, mechanical hyperalgesia and/or thermal hyperalgesia when administered (0.01-50 mg/kg, orally, parenterally or topically) immediately prior to testing as a single bolus, or for several days: once or twice or three times daily prior to testing.
|
C
|
C07
|
C07D
|
473
|
02
|
|||
11888046
|
US20090031788A1-20090205
|
Hydraulic scale for determing seeding density of a planter and method
|
ACCEPTED
|
20090122
|
20090205
|
[]
|
G01M302
|
["G01M302", "A01C1400"]
|
7547852
|
20070731
|
20090616
|
177
|
050000
|
71495.0
|
GIBSON
|
RANDY
|
[{"inventor_name_last": "Sallovitz", "inventor_name_first": "Maximo", "inventor_city": "Sante Fe", "inventor_state": "", "inventor_country": "AR"}]
|
A hydraulic scale for planter calibration is disclosed. The hydraulic scale includes a tube having indicia disposed thereon. The tube has a substantially closed bottom and a substantially open top. The indicia disposed on the tube include at least one scale having a zero line. The tube is configured to float substantially upright when positioned in a liquid, such that the zero line is substantially aligned with the surface of the liquid. A non-zero line portion of the scale is configured to align with the surface of the liquid when at least one of seeds and feed are placed within the tube.
|
1. A hydraulic scale for planter calibration, comprising: a tube having a substantially closed bottom and a substantially open top; and indicia disposed on the tube, the indicia including at least one scale having a zero line; wherein the tube is configured to float substantially upright when positioned in a liquid such that the zero line is substantially aligned with a surface of the liquid when the tube is substantially empty, and wherein a non-zero line portion of the scale is configured to align with the surface of the liquid when at least one of seeds and feed are placed within the tube. 2. The hydraulic scale of claim 1, wherein the indicia includes a plurality of scales and wherein each scale includes a zero line. 3. The hydraulic scale of claim 2, wherein each of the zero lines are substantially aligned with one another. 4. The hydraulic scale of claim 1, wherein the at least one scale corresponds to an area that was seeded by a planter. 5. The hydraulic scale of claim 1, wherein an intersection point between the surface of the liquid and the at least one scale indicates the seeding density of a planter. 6. The hydraulic scale of claim 5, wherein the seeding density of a planter is based on the distance traveled by a planter during a sample-obtaining run and the space between driller of the planter. 7. The hydraulic scale of claim 1, wherein the at least one scale displays the distance traveled by a planter during a sample-obtaining run. 8. The hydraulic scale of claim 1, wherein the at least one scale displays the distance between adjacent drillers of a planter. 9. The hydraulic scale of claim 1, furthering including a plurality of grooves disposed in the tube and further including a plurality of weighted rings, wherein each of the weighted rings being removably insertable into one of the plurality of grooves. 10. A method for determining seeding density of a planter, comprising: providing a hydraulic scale including a tube having indicia thereon, wherein the tube is configured to float substantially upright when positioned in a liquid, such that a zero line is substantially aligned with a surface of the liquid when the tube is substantially empty; collecting seeds placed by a planter as the planter travels a distance; placing the seeds within the hydraulic scale; placing the hydraulic scale within a liquid; and observing where the surface of the liquid intersects the indicia on the tube. 11. The method of claim 10, wherein the indicia includes a plurality of scales and wherein each scale includes a zero line. 12. The method of claim 11, wherein each of the zero lines are substantially aligned with one another. 13. The method of claim 10, wherein the at least one scale displays the area seeded by a planter. 14. The method of claim 10, wherein an intersection point between the surface of the liquid and the at least one scale indicates the seeding density of a planter. 15. The method of claim 14, wherein the seeding density of a planter is based on the distance traveled by a planter during a sample-obtaining run and the space between driller of the planter. 16. The method of claim 10, wherein the at least one scale displays the distance traveled by a planter during a sample-obtaining run. 17. The method of claim 10, wherein the at least one scale displays the distance between adjacent drillers of a planter. 18. The method of claim 10, furthering including a plurality of grooves disposed in the tube and further including a plurality of weighted rings, wherein each of the weighted rings being removably insertable into one of the plurality of grooves.
|
<SOH> BACKGROUND <EOH>1. Field of the Disclosure The present disclosure relates to an apparatus which measures seeds, fertilizers, insecticide and/or other granulated products. More particularly, the present disclosure relates to a hydraulic scale for determining the seeding density of a planter. 2. Background of the Art Farmers and other fieldworkers typically purchase various amounts of seed to plant in a planting filed. Tractors and other types of planters are often used to distribute and/or plant seeds and/or feed in the field. It is often a difficult task to determines how much seed being planted in a particular area or field and/or to determine if a particular planter is sufficiently calibrated. Further, this problem is magnified because different planters place seeds at different rates.
|
<SOH> SUMMARY <EOH>The present disclosure relates to a hydraulic scale for planter calibration. The hydraulic scale includes a tube having indicia disposed thereon. The tube has a substantially closed bottom and a substantially open top. The indicia disposed on the tube include at least one scale having a zero line. The tube is configured to float substantially upright when positioned in a liquid (e.g., water), such that the zero line is substantially aligned with the surface of the water. A non-zero line portion of the scale is configured to align with the surface of the water when at least one of seeds and feed are placed within the tube. The present disclosure also relates to a method of determining the seeding density of a planter. The method includes the steps of providing a hydraulic scale, including a tube having indicia thereon. The tube is configured to float substantially upright when positioned in a liquid, such that a zero line disposed on the tube is substantially aligned with the surface of the liquid. A non-zero line portion of the scale is configured to align with the surface of the liquid when at least one of seeds and feed are placed within the tube. The method also includes the steps of collecting seeds placed by a planter as the planter travels a distance, placing the seed within the hydraulic scale, placing the hydraulic scale within a liquid, and observing where the surface of the liquid intersects the scale.
|
BACKGROUND 1. Field of the Disclosure The present disclosure relates to an apparatus which measures seeds, fertilizers, insecticide and/or other granulated products. More particularly, the present disclosure relates to a hydraulic scale for determining the seeding density of a planter. 2. Background of the Art Farmers and other fieldworkers typically purchase various amounts of seed to plant in a planting filed. Tractors and other types of planters are often used to distribute and/or plant seeds and/or feed in the field. It is often a difficult task to determines how much seed being planted in a particular area or field and/or to determine if a particular planter is sufficiently calibrated. Further, this problem is magnified because different planters place seeds at different rates. SUMMARY The present disclosure relates to a hydraulic scale for planter calibration. The hydraulic scale includes a tube having indicia disposed thereon. The tube has a substantially closed bottom and a substantially open top. The indicia disposed on the tube include at least one scale having a zero line. The tube is configured to float substantially upright when positioned in a liquid (e.g., water), such that the zero line is substantially aligned with the surface of the water. A non-zero line portion of the scale is configured to align with the surface of the water when at least one of seeds and feed are placed within the tube. The present disclosure also relates to a method of determining the seeding density of a planter. The method includes the steps of providing a hydraulic scale, including a tube having indicia thereon. The tube is configured to float substantially upright when positioned in a liquid, such that a zero line disposed on the tube is substantially aligned with the surface of the liquid. A non-zero line portion of the scale is configured to align with the surface of the liquid when at least one of seeds and feed are placed within the tube. The method also includes the steps of collecting seeds placed by a planter as the planter travels a distance, placing the seed within the hydraulic scale, placing the hydraulic scale within a liquid, and observing where the surface of the liquid intersects the scale. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present disclosure are described hereinbelow with reference to the drawings wherein: FIG. 1 is a perspective view of an empty hydraulic scale floating in a liquid in accordance with an embodiment of the present disclosure; FIG. 2 is a perspective view of the hydraulic scale of FIG. 1, illustrated partially filled and floating in a liquid; and FIG. 3 is a top plan view of a tractor for use with the hydraulic scale of FIGS. 1 and 2. DETAILED DESCRIPTION Embodiments of the presently disclosed hydraulic scale are now described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. A hydraulic scale in accordance with the present disclosure is shown in FIGS. 1 and 2 and is referred to by reference numeral 100. Hydraulic scale 100 includes a tube 110 having indicia 120 disposed thereon. Tube 110 includes a top portion 112, which is substantially open and a bottom portion 114, which is substantially closed. Indicia 120 include at least one scale 122 having a zero line 124. As illustrated in FIG. 1, tube 110 is configured to float substantially upright (i.e., top portion 112 being in an upward position) when hydraulic scale 100 is positioned in a liquid 200 (e.g., water). Further, hydraulic scale 100 is weighted such that zero line 124 of scale 122 substantially aligns with a surface 202 of water 200, when hydraulic scale 100 is substantially empty. In an embodiment of the present disclosure, tube 110 includes at least one groove 130 disposed therein (three grooves 130a-130c are shown). Each groove 130 is configured to removably accept a weighted ring 140 (a single weighted ring 140 is shown at least partially within groove 130c). Thus, if hydraulic scale 100 is not optimally calibrated (i.e., surface 202 of water 200 is not substantially aligned with zero line 124 of scale 122 when hydraulic scale 100 is substantially empty), a user can insert (or remove) at least one weighted ring 140 into (or from) a respective groove 130 to help calibrate hydraulic scale 100. To use hydraulic scale 100, a quantity of seed 250 (and/or feed) is collected and is placed into hydraulic scale 100 and hydraulic scale 100 is placed in water 200 in a substantially upright position. The weight of seed 250 causes hydraulic scale 100 to move lower with respect to surface 202 of water 200, such that surface 202 is aligned with a non-zero portion of scale 122. As can be appreciated, the more seed 250 placed within tube 110, the lower hydraulic scale 100 moves with respect to surface 202 of water 200, thus corresponding to a higher number on scale 122. Moreover, different types of crops generally require different types of fertilizers, insecticides and/or seeding densities. With reference to FIG. 3, a contemplated use of hydraulic scale 100 is to determine the seeding (or sowing) density of a piece of equipment, such as a planter, seed drill, etc. (hereinafter referred to as planter 300). Generally, planter 300 includes drillers 310, which place seeds 250 in soil 400, and specifically in furrows 410 in soil 400. Drillers 310 of planter 300 are typically spaced substantially equidistantly from an adjacent driller. The distance between drillers 310 is referred to as letter x in FIG. 3. Distance x is typically adjustable and may be optimally set based on the type of seed 250 being planted. To determine the seeding density of a particular planter 300, the area covered by each driller 310 of planter 300 is first calculated. The area covered by each driller 310 is calculated by multiplying the distance x between drillers 310 by the distance traveled by planter 300. The distance traveled by planter 300 is referred to as letter y in FIG. 3. For example, if there is 1.7 feet (0.525 meters) between drillers 310 (x), and planter 300 travels 164 feet (50 meters) (y), the area covered by each driller 310 is: x*y, or 1.7 feet*164 feet=279 ft2 (or 0.00640 acres). Next, the relation between the quantity of seeds 250 distributed over this area and the weight of such seeds 250 is required. Thus, in accordance with an embodiment of the present disclosure, the seeds 250 distributed by a driller 310 of planter 300 are collected during a sample-obtaining run. To obtain these seeds 250, a user may remove a hose that connects a seed dosificator with a furrow opener and place a collecting structure (e.g., a bag) at an end of the hose to collect the seeds 250 placed by planter 300 along a distance y (e.g., 164 feet). The seed 250 collected by the above method is then placed in hydraulic scale 100 and hydraulic scale 100 is placed in water 200. The user then reads where surface 202 of water 200 intersects scale 122 (a non-zero line portion). This reading is the seeding density of the planter 300 (or of each driller 310). It is envisioned that hydraulic scale 100 includes several scales 122 thereon. According to a disclosed embodiment, each of several scales 122 relates to a different amount of area covered by each driller 310 of planter 300. For instance, a first scale 122a may include a distance x of 1.7 feet and a distance y of 164 feet (and/or an area of 0.00640 acres), a second scale 122b may include a distance x of 0.57 feet and a distance y of 164 feet (and/or an area of 0.00216 acres), etc. In an embodiment where hydraulic scale 100 includes more than one scale 122, the user reads surface 202 of water 200 where it intersects the appropriate scale 122. Once the seeding density of planter 300 is known, the user can determine if planter 300 has the desired/required seeding density for a given task. It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.
|
G
|
G01
|
G01M
|
3
|
02
|
|||
11951798
|
US20090146093A1-20090611
|
Ball Valve Housing Seat and Method of Securing the Same to a Ball Valve
|
ACCEPTED
|
20090527
|
20090611
|
[]
|
F16K300
|
["F16K300", "F16K118", "F16K302"]
|
7887025
|
20071206
|
20110215
|
251
|
315100
|
92703.0
|
BASTIANELLI
|
JOHN
|
[{"inventor_name_last": "Hartman", "inventor_name_first": "Thomas A.", "inventor_city": "St. Louis", "inventor_state": "MO", "inventor_country": "US"}, {"inventor_name_last": "Hartman", "inventor_name_first": "Brian T.", "inventor_city": "Mesa", "inventor_state": "AZ", "inventor_country": "US"}]
|
A valve comprises a housing, an annular housing seat, and a gate. The housing comprises a fluid inlet and a fluid outlet. The housing seat is fixed in position relative to the housing via epoxy. The gate comprises a gate seat and a fluid passageway that extends through the gate. The gate is movable relative to the housing between an open position and a closed position. The gate is also configured to allow fluid to flow from the fluid inlet through the fluid passageway to the fluid outlet when the gate is in the open position, and configured such that the gate seat engages the housing seat in a manner preventing fluid from flowing from the fluid inlet to the fluid outlet when the gate is in the closed position.
|
1. A valve comprising: a housing, the housing comprising a fluid inlet and a fluid outlet; an anular housing seat, the housing seat being fixed in position relative to the housing via epoxy; and a gate comprising a gate seat and a fluid passageway that extends through the gate, the gate being movable relative to the housing between an open position and a closed position, the gate being configured to allow fluid to flow from the fluid inlet through the fluid passageway to the fluid outlet when the gate is in the open position, the gate being configured such that the gate seat engages the housing seat in a manner preventing fluid from flowing from the fluid inlet to the fluid outlet when the gate is in the closed position. 2. A valve in accordance with claim 1 wherein the housing seat comprises annular undulations, and wherein there is interlocking geometry between the annular undulations and the epoxy. 3. A valve in accordance with claim 2 wherein the housing comprises annular undulations, and wherein there is interlocking geometry between the annular undulations of the housing and the epoxy. 4. A valve in accordance with claim 3 wherein the annular undulation of the housing are formed in a housing seat retainer that is removably secured to the valve along with the housing seat. 5. A valve in accordance with claim 1 wherein the housing seat is formed of steel. 6. A valve in accordance with claim 1 wherein the gate pivots about an axis relative to the housing as the gate moves between the first position and the second position, and wherein the housing seat and the gate seat are positioned to one side of the axis when the gate is in the closed position. 7. A valve in accordance with claim 1 further comprising first and second elastomeric rings, and wherein each of the elastomeric rings is positioned radially between the housing seat and the housing, and the epoxy extends between the elastomeric rings and between the housing seat and the housing. 8. A valve in accordance with claim 1 wherein the gate seat contacts a surface of the housing seat when the gate is in the closed position, and wherein the surface of the housing seat forms a portion of a sphere. 9. A method comprising: positioning a housing seat within a valve, the valve comprising a housing and a gate, the housing comprising a fluid inlet and a fluid outlet, the gate comprising a gate seat and a fluid passageway, the gate being movable relative to the housing between an open position and a closed position, the gate being configured to allow fluid to flow from the fluid inlet through the fluid passageway to the fluid outlet when the gate is in the open position, the positioning comprising moving the housing seat to a sealing position relative to the housing via the use of adjusting screws connecting the housing seat to the housing; and securing the housing seat in the sealing position relative to the housing via epoxy, the gate being configured such that the gate seat engages the housing seat in a manner preventing fluid from flowing from the fluid inlet to the fluid outlet when the gate is in the closed position and the housing seat is in the sealing position. 10. A method in accordance with claim 9 further comprising removing the adjusting screws from the valve after the step of securing the housing seat in the sealing position relative to the housing via epoxy. 11. A method in accordance with claim 9 wherein the gate is in the closed position and the housing seat is engaged against the gate seat during the step of securing the housing seat in the sealing position relative to the housing via the epoxy. 12. A method in accordance with claim 9 wherein the housing seat comprises annular undulations, and wherein the step of securing the housing seat in the sealing position relative to the housing via the epoxy occurs in a manner such that there is interlocking geometry between the annular undulations and the epoxy. 13. A method in accordance with claim 9 wherein the valve comprises first and second elastomeric rings that are spaced apart and are engaged with the housing seat and the housing, and wherein the step of securing the housing seat in the sealing position relative to the housing via the epoxy comprises injecting the epoxy in liquid form into a space between the first and second elastomeric rings. 14. A method in accordance with claim 13 wherein each of the first and second elastomeric rings acts as a dam in a manner containing the epoxy when the epoxy is in liquid form.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates generally to industrial ball valves. More particularly, this invention pertains to the use of epoxy to secure the housing seat to the housing of a ball valve. 2. Related Art Various types of valve seats are utilized in ball valves. In most ball valves, an annular housing seat is fixed in position relative to the housing of the valve. The housing seat is configured to engage against a portion of a pivotally movable plug or gate when the gate is in the closed position. In large industrial ball valves, the housing seat is typically a replaceable part. When installing a housing seat within a large industrial ball valve, either as an original or replacement seat, it is often necessary to perform a step of adjusting the alignment of the housing seat to ensure that full annular contact is made between the housing seat and gate seat when the gate seat in the closed position. Adjustment may also be necessary to ensure that there is sufficient and uniform compressive contact pressure such that, at full head pressure, fluid will not pass between the seals. To this end, it is known to align the housing seat relative to the housing using a plurality of pushing and pulling screws spaced circumferentially around the annular housing seat. The pushing and pulling screws allow the housing seat, which is typically metal, to be slightly deformed and allow for subtle changes in the orientation of the housing seat relative to the housing. This allows for the adjustment of the contact area and pressure between the housing seat and the gate seat. Once the housing seat is aligned, the screws are locked in place and the ball valve can be put into service. While the above-mentioned method of aligning and supporting a housing seat within a ball valve has utility, there are some disadvantages to such prior art methods. A primary disadvantage is that the screws exert non-uniform loads on the housing seat and, as a result, over time tend to cause the sealing surface of the housing seat to warp as a result of the uneven loading exerted thereupon. While such warpage may be slight and, at least initially, does not affect the sealing capability of the ball valve, it can lead to premature seal failure.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The present invention utilizes epoxy to secure a housing seat of a ball valve to the housing in a manner supporting the housing seat evenly around its circumference. In a first aspect of the invention, a valve comprises a housing, an annular housing seat, and a gate. The housing comprises a fluid inlet and a fluid outlet. The housing seat is fixed in position relative to the housing via epoxy. The gate comprises a gate seat and a fluid passageway that extends through the gate. The gate is movable relative to the housing between an open position and a closed position. The gate is also configured to allow fluid to flow from the fluid inlet through the fluid passageway to the fluid outlet when the gate is in the open position, and configured such that the gate seat engages the housing seat in a manner preventing fluid from flowing from the fluid inlet to the fluid outlet when the gate is in the closed position. In another aspect of the invention, a method comprises a step of positioning a housing seat within a valve. The valve comprises a housing and a gate. The housing comprises a fluid inlet and a fluid outlet. The gate comprises a gate seat and a fluid passageway, and is movable relative to the housing between an open position and a closed position. The gate is configured to allow fluid to flow from the fluid inlet through the fluid passageway to the fluid outlet when the gate is in the open position. The positioning step comprises moving the housing seat to a sealing position relative to the housing via the use of adjusting screws that connect the housing seat to the housing. The method further comprises a step of securing the housing seat in the sealing position relative to the housing via epoxy. The gate is configured such that the gate seat engages the housing seat in a manner preventing fluid from flowing from the fluid inlet to the fluid outlet when the gate is in the closed position and the housing seat is in the sealing position. Further features and advantages of the present invention, as well as the operation of an embodiment of the present invention, are described in detail below with reference to the accompanying drawings.
|
CROSS-REFERENCE TO RELATED APPLICATIONS None. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not Applicable. APPENDIX Not Applicable. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to industrial ball valves. More particularly, this invention pertains to the use of epoxy to secure the housing seat to the housing of a ball valve. 2. Related Art Various types of valve seats are utilized in ball valves. In most ball valves, an annular housing seat is fixed in position relative to the housing of the valve. The housing seat is configured to engage against a portion of a pivotally movable plug or gate when the gate is in the closed position. In large industrial ball valves, the housing seat is typically a replaceable part. When installing a housing seat within a large industrial ball valve, either as an original or replacement seat, it is often necessary to perform a step of adjusting the alignment of the housing seat to ensure that full annular contact is made between the housing seat and gate seat when the gate seat in the closed position. Adjustment may also be necessary to ensure that there is sufficient and uniform compressive contact pressure such that, at full head pressure, fluid will not pass between the seals. To this end, it is known to align the housing seat relative to the housing using a plurality of pushing and pulling screws spaced circumferentially around the annular housing seat. The pushing and pulling screws allow the housing seat, which is typically metal, to be slightly deformed and allow for subtle changes in the orientation of the housing seat relative to the housing. This allows for the adjustment of the contact area and pressure between the housing seat and the gate seat. Once the housing seat is aligned, the screws are locked in place and the ball valve can be put into service. While the above-mentioned method of aligning and supporting a housing seat within a ball valve has utility, there are some disadvantages to such prior art methods. A primary disadvantage is that the screws exert non-uniform loads on the housing seat and, as a result, over time tend to cause the sealing surface of the housing seat to warp as a result of the uneven loading exerted thereupon. While such warpage may be slight and, at least initially, does not affect the sealing capability of the ball valve, it can lead to premature seal failure. SUMMARY OF THE INVENTION The present invention utilizes epoxy to secure a housing seat of a ball valve to the housing in a manner supporting the housing seat evenly around its circumference. In a first aspect of the invention, a valve comprises a housing, an annular housing seat, and a gate. The housing comprises a fluid inlet and a fluid outlet. The housing seat is fixed in position relative to the housing via epoxy. The gate comprises a gate seat and a fluid passageway that extends through the gate. The gate is movable relative to the housing between an open position and a closed position. The gate is also configured to allow fluid to flow from the fluid inlet through the fluid passageway to the fluid outlet when the gate is in the open position, and configured such that the gate seat engages the housing seat in a manner preventing fluid from flowing from the fluid inlet to the fluid outlet when the gate is in the closed position. In another aspect of the invention, a method comprises a step of positioning a housing seat within a valve. The valve comprises a housing and a gate. The housing comprises a fluid inlet and a fluid outlet. The gate comprises a gate seat and a fluid passageway, and is movable relative to the housing between an open position and a closed position. The gate is configured to allow fluid to flow from the fluid inlet through the fluid passageway to the fluid outlet when the gate is in the open position. The positioning step comprises moving the housing seat to a sealing position relative to the housing via the use of adjusting screws that connect the housing seat to the housing. The method further comprises a step of securing the housing seat in the sealing position relative to the housing via epoxy. The gate is configured such that the gate seat engages the housing seat in a manner preventing fluid from flowing from the fluid inlet to the fluid outlet when the gate is in the closed position and the housing seat is in the sealing position. Further features and advantages of the present invention, as well as the operation of an embodiment of the present invention, are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a breakaway perspective view of a ball valve in accordance with the invention, and is shown with its gate in the closed position. FIG. 2 illustrates a top view of the ball valve shown in FIG. 1. FIG. 3 illustrates a cross-sectional view of the ball valve shown in FIGS. 1 and 2, taken about the line 3-3 shown in FIG. 2, and is shown with the gate in the open position. FIG. 4 illustrates a cross-sectional view of the ball valve shown in FIGS. 1 and 2, taken about the line 4-4 shown in FIG. 2, and is shown with the gate in the closed position. FIG. 5 illustrates a detail view of FIG. 4, as indicated in FIG. 4. FIG. 6 illustrates a breakaway perspective view of the housing seat retainer of the ball valve shown in FIGS. 1-4. FIG. 7 illustrates a breakaway perspective view of the housing seat of the ball valve shown in FIGS. 1-4. Reference numerals in the written specification and in the drawing figures indicate corresponding items. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An ball valve in accordance with the invention is shown in FIGS. 1-4, and is generally indicated by the reference numeral 10. The ball valve comprises a plug or gate 12, a housing 14, and a housing seat 16. The gate 12 comprises a pair of shafts 18, a gate seat 20, and a fluid passageway 22 that extends through the gate. The shafts 18 are aligned and pivotally attached the gate 12 to the housing 14 in a manner such that the gate can pivotally move between an open position (shown in FIG. 3) and a closed position (shown in FIG. 4) by applying a torque on at least one of the shafts 18. The gate seat 20 preferably has an annular sealing surface 24 that is adapted to engage the housing seat 16 in a manner preventing the flow of fluid through the valve 10 when the gate 12 is in the closed position. The gate seat 20 can be from of various materials including, but not limited to, metals and polymeric materials. In the case where the sealing surface 24 is formed of a relatively rigid material, such as metal, the gate seat 20 may be attached to the remainder of the gate 12 via a relatively resilient member to ensure that the sealing surface does not warp as a result of its attachment to the reminder of the gate. This also provides a resiliency to the gate seat 20 that facilitates an even seal. Preferably, the sealing surface 24 has the contour of a partial sphere. The fluid passageway 22 is configured to channel fluid in an unobstructed manner through the gate 12 along a path that is oriented generally perpendicular to the axis about which the gate pivots, when the gate is in the opened position. The housing 14 houses the gate 12 and ultimately is attached to either of or both a downstream fluid conduit and an upstream fluid conduit (not shown). The housing 14 comprises a fluid inlet 26 and a fluid outlet 28 for the ingress and egress of fluid that passes through the housing. It should be appreciated however that the valve 10 could in some cases operate in reverse and the fluid inlet 26 and fluid outlet 28 can serve as each other. The housing 14 also comprises a housing seat retainer 30, an inspection/service hatch cover 32, and shaft sleeves 34. The inspection/service hatch cover 32 can be removed to allow a person to inspect or service the valve, such as to change the gate seat 20, without removing the valve 10 from a fluid line. The shaft sleeves support the shafts 18 of the gate 12 and comprise internal O-rings (not shown) which sealably engage against the shafts to prevent fluid from escaping the housing 14 through the shaft openings. The housing seat retainer 30 preferably forms the fluid inlet 26 of the valve 10 and connects the housing seat 16 to the remainder of the housing 14. The housing seat retainer 30 is configured such that it is removable from the remainder of the housing 14 so as to allow the housing seat 16, and sometimes the housing seat retainer itself as well, to be replaced. Preferably bolts (not shown) are used to secure the housing seat retainer 30 to the remainder of the housing 14. FIG. 6 depicts the housing seat retainer 30 by itself, from the opposite side of how it is shown in FIG. 1. The housing seat retainer 30 comprises a plurality of housing through-holes 36 for securing the housing seat retainer 30 to the housing 14, and a plurality of fluid line attachment blind-holes 38 for securing a flange of a fluid line to the valve 10. The housing seat retainer 30 also comprises first 40 and second 42 internal cylindrical sealing surfaces. A plurality of preferably V-shaped grooves adjacent the first cylindrical sealing surface 40 forms annular undulations 44. The undulations 44 terminate at a planar annular shelf 46, which extends to the second cylindrical sealing surface 42. A plurality of adjustment screw holes 48 extend through the housing seat retainer 30 to the annular shelf 46. The housing seat 16 is shown by itself in FIG. 7 and comprises a sealing surface 50. The sealing surface preferably has the contour of a partial sphere, closely matching that of the sealing surface 24 of the gate seat 20. The housing seat 16 also comprises preferably V-shaped grooves that form external annular undulations 52. Additionally, two O-ring channels 54 are formed into the external surface of the housing seat 16 on axially opposite sides of the undulations 52. The housing seat 16 also has a planar annular shelf 56 that comprises a plurality of threaded blind-holes 58. Still further, a pair of epoxy ports 60 extend radially through the housing seat 16 between the O-ring channels 54. Prior to installation into the housing 14 of the valve 10, resilient O-rings 62 are positioned in the O-ring channels 54 of the housing seat 16 and then the housing seat is initially secured to the housing seat retainer 30. This is done with the housing seat retainer 30 disconnected from the housing 14. During this procedure, the housing seat 16 is secured to the housing seat retainer 30 via a plurality of adjustment screws (not shown) which are inserted through the adjustment screw holes 48 of the housing seat retainer 30 and into the blind-holes 58 of the housing seat. Some of the screws act as push screws, which can be used to apply a force against the housing seat 16 in a direction away from the housing seat retainer 30, and some act as pull screws, which can be used to apply force to the housing seat in a direction toward the housing seat retainer. It should be appreciated that, in the case of the push screws, the adjustment screw holes 48 of the housing seat retainer 30 are preferably threaded while the blind-holes 58 of the housing seat 16 are preferably not, and that conversely, in the case of the pull screws, the adjustment screw holes of the housing seat retainer are preferably not threaded while the blind-holes of the housing seat preferably have threads. It should also be appreciated that other forms of adjustment screws can serve the same purpose. Assembled as described, one of the O-rings 62 sealably engages against the first cylindrical sealing surface 40 of the housing seat retainer 30, and the other sealably engages against the second cylindrical sealing surface 42 of the housing seat retainer 30. Additionally, the undulations 44 of the housing seat retainer 30 and the undulations 52 of the housing seat 16 face each other in a radially spaced apart manner. Still further, the shelf 46 of the housing seat retainer 30 faces the shelf 56 of the housing seat 16 in an axially spaced apart manner. The installation procedure continues by placing the above-described assembly against the housing 14, with the housing seat 16 extending into the housing. The housing seat retainer 30 is then secured, via bolts passing through the housing holes 36 and into the housing 14. With the gate 12 in the closed position, the adjusting screws are then used to adjust the position of the housing seat 16 relative to the housing 14 in a manner such that the sealing surface 50 of the housing seat makes full annular contact with the sealing surface 24 of the gate seat 20 and such that a sufficient and uniform force exists therebetween to create an effective fluid seal. Once proper alignment and contact pressure is achieved, liquid epoxy is injected into the space that lies between the housing seat retainer 30 and the housing seat 16 and between the O-rings 62. This is preferably done by injecting epoxy into the lower epoxy port 60 of the housing seat 16 while allowing air and epoxy to escape through the higher epoxy port. During this process, the O-rings 62 act as dams to prevent the flow of epoxy past the O-rings. This preferably continues until it appears that the space is sufficiently devoid of air, after which time the epoxy ports are sealed and the epoxy is allowed to cure into solid form. Once cured, the adjustment screws are preferably removed such that contact pressure exerted on the sealing surface 50 of the housing seat 16 is borne by compression of the cured epoxy 64 between the shelves 46, 46 of the housing seat retainer 30 and the housing seat 16, and by shear through the cured epoxy between the undulations 44, 52. This ensures that there is no point loading which could warp the housing seat 16 over time. It should also be appreciated that the undulations 44, 52 create interlocking geometry with the epoxy 64 that lies therebetween. While not necessarily necessary, the interlocking geometry ensures that no slippage can occur between the epoxy 64 and either the housing seat retainer 30 or the housing seat 16. After the above describe procedures have been preformed, the valve 10 can be reattached to a fluid line and put into service. It should be appreciate that the procedure can be used in connection with either a new valve and an original housing seat, or replacing the housing seat 16 of a used valve. In view of the foregoing, it should be appreciated that several advantages of the invention are achieved and attained. As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by the above-described exemplary embodiment, but should be defined only in accordance with the following claims appended hereto and their equivalents. Furthermore, it should be understood that when introducing elements of the present invention in the claims or in the above description of the preferred embodiment of the invention, the terms “comprising,” “including,” and “having” are intended to be open-ended and mean that there may be additional elements other than the listed elements. Additionally, the term “portion” should be construed as meaning some or all of the item or element that it qualifies. Moreover, use of identifiers such as first, second, and third should not be construed in a manner imposing any relative position or time sequence between limitations. Still further, the order in which the steps of any method claim that follows are presented should not be construed in a manner limiting the order in which such steps must be performed.
|
F
|
F16
|
F16K
|
3
|
00
|
|||
10534956
|
US20070273013A1-20071129
|
Packaging for Micro Electro-Mechanical Systems and Methods of Fabricating Thereof
|
ACCEPTED
|
20071114
|
20071129
|
[]
|
H01L2320
|
["H01L2320", "H01L2154"]
|
8476096
|
20070427
|
20130702
|
438
|
050000
|
58033.0
|
GEBREYESUS
|
YOSEF
|
[{"inventor_name_last": "Kohl", "inventor_name_first": "Paul", "inventor_city": "Atlanta", "inventor_state": "GA", "inventor_country": "US"}, {"inventor_name_last": "Ayazi", "inventor_name_first": "Farrokh", "inventor_city": "Atlanta", "inventor_state": "GA", "inventor_country": "US"}]
|
Embodiments of the present disclosure provide systems and methods for producing micro electro-mechanical device packages. Briefly described, in architecture, one embodiment of the system, among others, includes a micro electro-mechanical device formed on a substrate layer; and a thermally decomposable sacrificial structure protecting at least a portion of the micro electro-mechanical device, where the sacrificial structure is formed on the substrate layer and surrounds a gas cavity enclosing an active surface of the micro electro-mechanical device. Other systems and methods are also provided.
|
1. A micro electro-mechanical device packaging system, comprising: a micro electro-mechanical device formed on a substrate layer; and a protective structure protecting at least a portion of the micro electro-mechanical device, wherein the protective structure is formed on the substrate layer and surrounds a gas cavity enclosing an active surface of the micro electro-mechanical device, the protective structure being a solid. 2. The system of claim 1, wherein the substrate layer comprises silicon material. 3. The system of claim 1, wherein the substrate layer comprises non-silicon material. 4. The system of claim 1, wherein the protective structure comprises a metal material. 5. The system of claim 4, wherein the metal material is deposited by sputtering. 6. The system of claim 1, wherein the protective structure comprises an overcoat polymer material. 7. The system of claim 6, wherein the overcoat polymer material is deposited by spin-coating. 8. The system of claim 6, further comprising: an additional protective structure surrounding the overcoat polymer material. 9. The system of claim 8, wherein the additional protective structure comprises a metal material. 10. The system of claim 1, wherein the protective structure comprises a modular polymer that includes the characteristic of being permeable to the decomposition gases produced by the decomposition of a sacrificial polymer while forming the gas cavity. 11. The system of claim 1, wherein the gas cavity is substantially free of residue. 12. The system of claim 11, wherein the gas cavity is vacuum-packed. 13. The system of claim 1, wherein protective structure has not been preformed before being applied to the substrate layer. 14. The system of claim 13, further comprising: a metal packaging frame, the micro electro-mechanical device being attached to the metal packaging frame; and a coating material encapsulating a portion of the micro electro-mechanical device and metal packaging frame assembly. 15. A micro electro-mechanical device packaging system, comprising: a micro electro-mechanical device formed on a substrate layer; and a thermally decomposable sacrificial structure protecting at least a portion of the micro electro-mechanical device, wherein the sacrificial structure is formed into a gas cavity enclosing an active surface of the micro electro-mechanical device. 16. The system of claim 15, wherein the sacrificial structure comprises a photo-definable polycarbonate material. 17. The system of claim 15, wherein the sacrificial structure is deposited by spin-coating followed by patterning. 18. The system of claim 17, wherein the sacrificial structure comprises a photo-definable material. 19. The system of claim 15, wherein the sacrificial structure is dispensed by a syringe dispensing tool. 20. The system of claim 19, wherein the sacrificial structure comprises a non-photo-definable material. 21. The system of claim 15, further comprising: a metal packaging frame, the micro electro-mechanical device being attached to the metal packaging frame; and a coating material encapsulating a portion of the micro electro-mechanical device and metal packaging frame assembly, the coating material including the characteristic of being permeable to the decomposition gases produced by the decomposition of a sacrificial polymer at a temperature exceeding a curing temperature of the coating material. 22. The system of claim 21, wherein the coating material comprises an epoxy resin. 23. The system of claim 21, further comprising: an overcoat structure surrounding the sacrificial structure, the overcoat structure comprising a modular polymer that includes the characteristic of being permeable to the decomposition gases produced by the decomposition of a sacrificial polymer from inside the gas cavity. 24. A method for producing a micro electro-mechanical device package, comprising the steps of: forming a thermally decomposable sacrificial layer on a substrate of a micro electro-mechanical device, the sacrificial layer encapsulating a portion of the micro electro-mechanical device; forming a protective layer around the sacrificial layer; and thermally decomposing the sacrificial layer, wherein decomposed molecules of the sacrificial layer permeate through the protective layer, and wherein a gas cavity is formed where the thermally decomposable sacrificial layer was formed. 25. The method of claim 24, further comprising the steps of: depositing the sacrificial layer by spin-coating; and patterning the sacrificial layer. 26. The method of claim. 24, wherein the sacrificial layer has a decomposition temperature less than a decomposition temperature of the substrate and a decomposition temperature of the protective layer. 27. The method of claim 24, wherein the substrate comprises a silicon material. 28. The method of claim. 24, wherein the substrate comprises a non-silicon material. 29. The method of claim 24, wherein the thickness of the protective layer is within the range of 50 nm and 500 μm. 30. The method of claim 24, wherein the protective layer has not been perforated. 31. The method of claim 24, wherein the protective layer is substantially free of sacrificial material after the sacrificial material has been thermally decomposed. 32. The method of claim 24, wherein the protective layer provides an airtight enclosure around the gas cavity. 33. The method of claim 32, wherein the protective layer provides protection from mechanical forces. 34. The method of claim 33, wherein the protective layer further provides protection against water. 35. The method of claim 34, wherein the protective layer further provides protection against oxygen gas. 36. The method of claim 34, wherein the protective layer further provides protection against exposure to gaseous materials. 37. The method of claim 24, wherein the micro electro-mechanical device includes a released mechanical structure before the sacrificial material is formed. 38. The method of claim 24, further comprising the steps of: before the protective layer is formed, attaching the micro electro-mechanical device to a metal packaging frame, wherein the protective layer comprises an epoxy resin encapsulating the micro electro-mechanical device and metal packaging frame assembly. 39. The method of claim 38, further comprising the step of: heating the micro assembly at a temperature for curing the protective layer; and heating the micro assembly at a temperature for decomposing the sacrificial layer, the temperature for decomposing the sacrificial layer exceeding the temperature for curing the protective layer. 40. The method of claim 24, further comprising the step of: forming a barrier layer around the protective layer, the barrier layer providing a stronger protection against mechanical forces than the protective layer. 41. The method of claim 40, wherein the barrier layer comprises a metal material. 42. The method of claim 40, further comprising the steps of: creating a vacuum inside the gas cavity by heating the micro electro-mechanical device in a chamber; and after the vacuum is created, forming a barrier layer around the protective layer within the chamber to provide a vacuum-packed enclosure around the gas cavity, the barrier layer comprising a metal material. 43. The method of claim 42, further comprising the steps of: after the barrier layer is formed, attaching the micro electro-mechanical device to an integrated circuit package structure; and encapsulating the electro-mechanical device and integrated circuit package structure in a protective coating. 44. The method of claim 42, wherein the integrated circuit package structure comprises a leadframe. 45. The method of claim 42, wherein the integrated circuit package structure comprises a ceramic package. 46. The method of claim 42, wherein the step of thermally decomposing the sacrificial layer occurs inside the vacuum chamber. 47. The method of claim 24, further comprising the steps of: after the sacrificial layer is decomposed, attaching the micro electro-mechanical device to an integrated circuit package structure; and encapsulating the electro-mechanical device and package structure in a protective coating. 48. The method of claim 47, wherein the integrated circuit package structure comprises a leadframe. 49. The method of claim 47, wherein the integrated circuit package structure comprises a ceramic package. 50. The method of claim 24, wherein thermal decomposition temperature of the sacrificial material is less than 100 degrees Celsius.
|
<SOH> BACKGROUND <EOH>Adapting microelectronic packages to micro electro-mechanical system (MEMS) devices involves several challenging packaging requirements. The typical three-dimensional and moving elements of many MEMS devices generally require some sort of cavity package to provide free space above the active surface of the MEMS device. The interior of the cavity must generally be free of contaminants, including excessive outgassing of materials. The MEMS device might also require thermal isolation within the package, and a mounting method that minimizes mechanical stress on the device. The cavity may be evacuated or be filled with atmosphere-controlling agents such as getters. In addition to these requirements, MEMS devices are vulnerable to damage during what would otherwise be normal micropackaging procedures. The presence of three-dimensional mechanical structures that can move adds fragility to unpackaged MEMS devices. For example, movable MEMS structures make contact and permanently stick together (stiction effect) if roughly handled. Further, the cost of MEMS packaging has become a critical issue for many applications. For instance, 50-90% of the cost in producing most MEMS devices is spent in packaging the MEMS devices. For instance, the surface features and cavity requirements of MEMS devices typically prohibit application of low-cost transfer-molded plastic packaging used for most integrated circuits. Moreover, common encapsulation techniques such as injection molding, often requiring high pressures that may easily damage microstructures Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.
|
<SOH> SUMMARY <EOH>Embodiments of the present disclosure provide systems and methods for producing micro electro-mechanical device packages. Briefly described, in architecture, one embodiment of the system, among others, includes a micro electro-mechanical device formed on a substrate layer; and a thermally decomposable sacrificial structure protecting at least a portion of the micro electro-mechanical device, where the sacrificial structure is formed on the substrate layer and surrounds a gas cavity enclosing an active surface of the micro electro-mechanical device. Embodiments of the present disclosure can also be viewed as providing methods for producing micro electro-mechanical device packages. In this regard, one embodiment of such a method, among others, can be broadly summarized by the following steps: forming a thermally decomposable sacrificial layer on a substrate of a micro electro-mechanical device, where the sacrificial layer surrounds a gas cavity encapsulating a portion of the micro electro-mechanical device; forming a protective layer around the sacrificial layer; and thermally decomposing the sacrificial layer, where decomposed molecules permeate through the protective layer and a gas cavity is formed where the thermally decomposable sacrificial layer was formed. Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure.
|
CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to copending U.S. provisional application entitled, “Hermetic Packaging for MEMS,” having Ser. No. 60/553,178, filed Mar. 15, 2004, which is entirely incorporated herein by reference. TECHNICAL FIELD The present disclosure is generally related to micro electro-mechanical devices and, more particularly, is related to packaging of micro electro-mechanical devices. BACKGROUND Adapting microelectronic packages to micro electro-mechanical system (MEMS) devices involves several challenging packaging requirements. The typical three-dimensional and moving elements of many MEMS devices generally require some sort of cavity package to provide free space above the active surface of the MEMS device. The interior of the cavity must generally be free of contaminants, including excessive outgassing of materials. The MEMS device might also require thermal isolation within the package, and a mounting method that minimizes mechanical stress on the device. The cavity may be evacuated or be filled with atmosphere-controlling agents such as getters. In addition to these requirements, MEMS devices are vulnerable to damage during what would otherwise be normal micropackaging procedures. The presence of three-dimensional mechanical structures that can move adds fragility to unpackaged MEMS devices. For example, movable MEMS structures make contact and permanently stick together (stiction effect) if roughly handled. Further, the cost of MEMS packaging has become a critical issue for many applications. For instance, 50-90% of the cost in producing most MEMS devices is spent in packaging the MEMS devices. For instance, the surface features and cavity requirements of MEMS devices typically prohibit application of low-cost transfer-molded plastic packaging used for most integrated circuits. Moreover, common encapsulation techniques such as injection molding, often requiring high pressures that may easily damage microstructures Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies. SUMMARY Embodiments of the present disclosure provide systems and methods for producing micro electro-mechanical device packages. Briefly described, in architecture, one embodiment of the system, among others, includes a micro electro-mechanical device formed on a substrate layer; and a thermally decomposable sacrificial structure protecting at least a portion of the micro electro-mechanical device, where the sacrificial structure is formed on the substrate layer and surrounds a gas cavity enclosing an active surface of the micro electro-mechanical device. Embodiments of the present disclosure can also be viewed as providing methods for producing micro electro-mechanical device packages. In this regard, one embodiment of such a method, among others, can be broadly summarized by the following steps: forming a thermally decomposable sacrificial layer on a substrate of a micro electro-mechanical device, where the sacrificial layer surrounds a gas cavity encapsulating a portion of the micro electro-mechanical device; forming a protective layer around the sacrificial layer; and thermally decomposing the sacrificial layer, where decomposed molecules permeate through the protective layer and a gas cavity is formed where the thermally decomposable sacrificial layer was formed. Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS Many aspects of the disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. FIG. 1 is a diagram of a MEMS package in accordance with one embodiment of the present disclosure. FIG. 2 is a flowchart diagram describing an illustrative process for fabricating the MEMS package of FIG. 1. FIG. 3 is a diagram showing the fabrication steps in the process of FIG. 2. FIG. 4 is a diagram describing one embodiment of a process for performing the step of applying a sacrificial layer as performed in FIG. 2. FIG. 5 is a diagram shown an embodiment of a MEMS device that is suited for the process of FIG. 4. FIG. 6 is a diagram describing one embodiment of a process for performing the step of applying a sacrificial layer as performed in FIG. 2. FIG. 7 is a diagram shown an embodiment of a MEMS device that is suited for the process of FIG. 6. FIG. 8 is diagram. shown an embodiment of a MEMS device that is suited for an etching process for performing the process of applying a sacrificial layer as performed in FIG. 2. FIGS. 9A-9D are pictures illustrating a packaging process of FIG. 4 for a SOI beam resonator. FIGS. 10A-10F are pictures illustrating a packaging process of FIG. 6 for a HARPSS Polysilicon ring gyrcoscope. FIGS. 11A-11B are diagrams showing the frequency response of the SOI beam resonator of FIGS. 9A-9D before and after packaging. FIGS. 12-15 are diagrams showing different embodiments of a MEMS package that may be performed using portions of the process of FIG. 2. FIG. 16 is a diagram describing a fabrication process for attaching a MEMS device to a leadframe package, in accordance with the present disclosure. FIG. 17 is a diagram showing a variety of packaging technologies that can be employed with MEMS packages of the present disclosure. DETAILED DESCRIPTION FIG. 1 shows a MEMS device package 100 in accordance with one embodiment of the present disclosure. Accordingly, the MEMS device package 100 is used to package a freestanding MEMS structure 110 and generally includes a substrate layer 105, one or more MEMS structure(s) 110 formed on the substrate layer 105; a cavity or air gap or gas cavity 108 surrounding the freestanding MEMS structure 110; a barrier layer 120 around the cavity 108 to provide mechanical, electrical, chemical, and/or environmental protection for the MEMS device; a plurality of electrical feedthroughs extending from inside of the cavity to the outside (through or under the barrier layer 120, to guide electrical signals from outside to inside); and contacts 130 formed on the substrate 105 for connecting the package 100 to external points or terminals. After packaging the freestanding or released MEMS structure 110 in a MEMS package 100, the package 100 may then be attached to a circuit board or system in a variety of unique and different approaches, as is discussed hereinafter. Substrate layer 105 can be made of materials appropriate for a particular MEMS system or device. Exemplar materials include, but are not limited to, glasses, diamond, quartz, sapphire, silicon, silicon compounds, germanium, germanium compounds, gallium, gallium compounds, indium, indium compounds, or other semiconductor materials and/or compounds. In addition, substrate layer l 05 can include non-semiconductor substrate materials, including any dielectric materials, metals (e.g., copper and aluminum), or ceramics or organic materials found in printed wiring boards, for example. The contacts 130 are formed from conductors such as metals and/or metal alloys, subject to appropriate considerations such as adhesion and thermal properties. As previously stated, the barrier layer 120 around the cavity 108 provides mechanical, electrical, chemical, and/or environmental protection for the MEMS device(s). Depending on the particular MEMS device or the particular application, different levels of protection may be desired. Generally, the air gap or cavity is an enclosed region containing a gas that is not necessarily breathing air and in some embodiments, the air gap is under vacuum conditions. The air gap or cavity is generally enclosed by a super structure. Generally, the MEMS structure 110 is packaged to ensure protection of the device from the working environment and protection of the environment from device material and operation. For example, one level of protection provides protection from interference from other mechanical structure or objects to ensure structural integrity of the MEMS structure 110. In this type of enclosure, the barrier layer 120 should be made of a material that can withstand the general rigors of a particular operating environment of a MEMS device. Another additional level of protection may further provide protection from exposure to oxygen or water (e.g., a hermetic enclosure). Accordingly, for this type of protection, the barrier layer 120 is generally made of a metal material that provides an airtight seal around the air cavity 108. In addition, some barrier levels 120 may also provide an additional level of protection which further provides protection from exposure to any outside gases. For this last level of protection, a vacuum is produced inside the air cavity 108 and the barrier layer 20 is generally made of a metal material that maintains the vacuum inside the air cavity 108. In accordance with one embodiment of the present disclosure, a process 200 for fabricating the MEMS device package 100 is discussed with regard to FIG. 2 and FIG. 3. This process 200 is based upon thermal decomposition of a sacrificial material, as described herein. It should be noted that for clarity, some portions of the fabrication process are not included in FIG. 2. As such, the following fabrication process is not intended to be an exhaustive list that includes all steps required for fabricating the MEMS device package 100. In addition, the fabrication process is flexible because the process steps may be performed in a different order than the order illustrated in FIG. 2 or some steps may be performed simultaneously. Referring now to FIGS. 2 and 3, a thermally decomposable sacrifical polymer (e.g., Unity 200, Promerus, LLC, Brecksville, Ohio) is applied (210) to the surface of a released MEMS device 310 to produce a MEMS device package 320 having a sacrificial layer 325. Sacrificial polymer material is patterned so as to encapsulate the surface or portions of the surface of the MEMS device 310 to produce the sacrificial layer 325. For example, a photosensitive or photodefinable sacrificial polymer material may be used to make the sacrificial layer 325. Accordingly, the photodefinable polymer can be deposited onto the substrate 328 using techniques such as, for example, spin-coating, doctor-blading, sputtering, lamination, screen or stencil-printing, melt dispensing, chemical vapor deposition (CVD), and plasma-based deposition systems. Then, after patterning with the sacrificial material 325, the MEMS device is overcoated with a dielectric material (e.g., Avatrel, Polymide, SU8) 335 on top of the sacrificial layer 325 and any other desired areas on the MEMS structure. As such, the overcoat layer is applied (220) to the MEMS structure 320 to produce the MEMS device package 330 having sacrificial layer 325 and overcoat layer 335. The overcoat layer 335 can be deposited onto the substrate 328 using techniques such as, for example, spin coating, photo-defining methods, doctor-blading, sputtering, lamination, screen or stencil-printing, melt dispensing, chemical vapor deposition (CVD), and plasma-based deposition systems. The overcoat materials can also be patterned to expose features, such as bond pads or contacts. After the overcoat 335 is prepared, the sacrificial layer 325 is decomposed by heating the sacrifical polymer material of the sacrifical layer 325 to a temperature sufficient to decompose the polymer (e.g., 200-250° C.). For example, the sacrificial layer 325 may be decomposed (230) in. an oven by exceeding the thermal decomposition temperature of the sacrificial layer 325 to produce a MEMS device package 340 having a substantially residue-free, low-residue air gap, or a residue-free cavity 348 surrounded by overcoat layer 335. Residues below a “substantial” value have little or no effect on the final product and can be considered “residue free.” For example, in MEMS devices, residues less than 10 nm typically have no effect on the end-product and are considered residue free. During this process, the decomposition products of the sacrificial layer 325 diffuse or permeate through the overcoat layer 335. In an additional step, additional metal material 355 is added (240) to the MEMS structure over the overcoat layer 335 (e.g., via sputtering and patterning the metal material) to produce a MEMS device package 350 with a metal cap or barrier 355 protecting an active surface 358 of a MEMS device. The metal barrier 355 provides one type of protection for the MEMS device 310 from external forces or elements. In particular, metals are known to provide a hermetic barrier. Therefore, the metal hermetic barrier 355 allows the MEMS device to be brought into ambient conditions. In some embodiments, vacuum packaging of a MEMS device is desired. One embodiment, among others, for implementing vacuum packaging of a MEMS device employs the previously described process 200. However, to add the additional metal material in step 335, the MEMS device 340 is placed in a vacuum chamber, such as in an evaporator, and air within the air cavity region 348 is evacuated. While under vacuum, metal is then deposited over the overcoat material, as previously described in step 255. The metal barrier 355 prevents air from entering the region encapsulated by metal, thus providing a vacuum package for the MEMS device. Note, in some embodiments, the step for removing the sacrificial layer may also be performed in a vacuum chamber such that multiple steps may then be performed simultaneously. Further note, that in some embodiments, a MFMS package is produced without undergoing each of the aforementioned steps of FIG. 2 and is still readily suitable for further processing in order to provide electrical connections to external points or terminals, as is discussed hereinafter. A sacrificial polymer used to produce the sacrificial layer 325 can be a polymer that slowly decomposes and does not produce undue pressure build-up while forming the air cavity region 348 within the surrounding materials. In addition, the decomposition of the sacrificial polymer produces gas molecules small enough to permeate the overcoat layer 335. Further, the sacrificial polymer has a decomposition temperature less than the decomposition or degradation temperature of the MEMS structure and overcoat material. Still further, the sacrificial material should have a decomposition temperature above the deposition or curing temperature of an overcoat material but less than the degradation temperature of the components in the structure in which the sacrificial polymer is being used. The sacrificial polymer can include compounds such as, but not limited to, polynorbomenes, polycarbonates, polyethers, polyesters, functionalized compounds of each, and combinations thereof. The polynorbomene can include, but is not limited to, alkenyl-substituted norbonene (e.g., cyclo-acrylate norbornene). The polycarbonate can include, but is not limited to, norbornene carbonate, polypropylene carbonate, polyethylene carbonate, polycyclohexene carbonate, and combinations thereof. In addition, the sacrificial polymer can include additional components that alter the processability (e.g., increase or decrease the stability of the sacrificial polymer to thermal and/or light radiation) of the sacrificial polymer. In this regard, the components can include, but are not limited to, photoinitiators and photoacid initiators. Embodiments of the disclosed sacrificial composition include, but are not limited to, a sacrificial polymer and one or more positive tone or negative tone component. The positive tone component can include a photoacid generator. For example, the sacrificial component can include either a negative tone component and/or a positive tone component. The negative tone component can include compounds that generate a reactant that would cause the crosslinking in the sacrificial polymer. The negative tone component can include compounds, such as, but not limited to, a photosensitive free radical generator. Alternative negative tone components can be used, such as photoacid generators (e.g., in epoxide-functionalized systems). A negative tone photosensitive free radical generator is a compound which, when exposed to light breaks into two or more compounds, at least one of which is a free radical. In particular, the negative tone photoinitiator can include, but is not limited to, bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (Irgacure 819, Ciba Specialty Chemicals Inc.); 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (Irgacure 369, Ciba); 2,2-dimethoxy-1,2-diphenylethan-1-one (Irgacure 651, Ciba); 2-methyl-1[4-(methylthio)-phenyl]-2-morpholinopropan-1-one (Irgacure 907, Ciba); benzoin ethyl ether (BEE, Aldrich); 2-methyl-4′-(methylthio)-2-morpholino-propiophenone; 2,2′-dimethoxy-2-phenyl-acetophenone (Irgacure 1300, Ciba); 2, 6-bis(4-azidobenzylidene)-4-ethylcyclohexanone (BAC-E), and combinations thereof. The positive tone components can include, but is not limited to, photoacid generator(s). More specifically, the positive tone photoacid generator can include, but is not limited to, nucleophilic halogenides (e.g., diphenyliodonium salt, diphenylfluoronium salt) and complex metal halide anions (e.g., triphenylsulphonium salts). In particular, the photoacid generator can be tetrakis(pentafluorophenyl)borate-4-methylphenyl[4-(1-methylethyl)phenyl]iodonium (DPI-TPFPB); tris(4-t-butylphenyl)sulfonium tetrakis-(pentafluorophenyl)borate (TTBPS-TPFPB); tris(4-t-butylphenyl)sulfonium hexafluorophosphate (TTBPS-HFP); triphenylsulfonium triflate (TPS-Tf); bis(4-tert-butylphenyl)iodonium triflate (DTBPI-Tf); triazine (TAZ-101); triphenylsulfonium hexafluoroantimonate (TPS-103); Rhodosilm Photoinitiator 2074 (FABA); triphenylsulfonium bis(perfluoromethanesulfonyl) imide (TPS-N1); di-(p-t-butyl) phenyliodonium bis(perfluoromethanesulfonyl) imide (DTBPI-N1); triphenylsulfonium; tris(perfluoromethanesulfonyl) methide (TPS-C1); di-(p-t-butylphenyl)iodonium tris(perfluoromethanesulfonyl)methide (DTBPI-C1); and combinations thereof. The photoacid generator can be from about 0.5% to 5% by weight of the sacrificial composition. In particular, the photoacid generator can be from about 1% to 3% by weight of the sacrificial composition. The remaining percentage of the sacrificial composition not accounted for in the photoacid generator and sacrificial polymer (e.g., from about 50% to about 99%) can be made up with solvent, such as, but not limited to, mesitylene, N-methyl-2-pyrrolidinone, propylene carbonate, anisole, cyclohexanone, propyleneglycol monomethyl ether acetate, N-butyl acetate, diglyme, ethyl 3-ethoxypropionate, and combinations thereof. The thermal decomposition of the sacrificial polymer can be performed by heating the MEMS device package to the decomposition temperature of the sacrificial polymer and holding at that temperature for a certain period of time (e.g., 1-2 hours). Thereafter, the decomposition products diffuse or permeate through the overcoat polymer layer leaving a virtually residue-free hollow structure (air cavity). The overcoat layer 335 can be any modular polymer or deposited film (e.g. silicon dioxide, silicon nitride, etc.) that includes the characteristic of being permeable or semi-permeable to the decomposition gases produced by the decomposition of a sacrificial polymer while forming the air gap or cavity. In addition, the overcoat polymer layer has elastic properties so as to not rupture or collapse under fabrication and use conditions. Further, the overcoat layer 335 is stable in the temperature range in which the sacrificial polymer decomposes. Examples of the overcoat layer 335 include compounds such as, for example, polyimides, polynorbomenes, epoxides, polyarylenes ethers, and parylenes. More specifically, the overcoat layer 335 includes compounds such as Amoco Ultradel™ 7501, BF Goodrich Avatrel™ Dieelectric Polymer, DuPont 2611, DuPont 2734, DuPont 2771, and DuPont 2555. The overcoat layer 335 can be deposited on the substrate using techniques such as, for example, spin coating, doctor-blading, sputtering, lamination, screen or stencil-printing, chemical vapor deposition (CVD), plasma based deposition systems, etc. A variety of approaches may be used to apply the thermally decomposable sacrificial layer and overcoat layer to a MEMS device. As such, FIG. 4 shows a diagram describing one such process this is aptly suited for packaging surface micromachined MEMS devices such as silicon on insulator (SOI) resonators or other MEMS devices with small holes (e.g., H>>g and t<<50 μm, where H is height of air cavity; g is width of hole; and t is thickness of sacrificial layer), as represented by FIG. 5. In this packaging via patterning (PVP) approach, a photo-definable sacrificial polymer Unity 200 (Promerus, LLC, Brecksville, Ohio) is first spin-coated on the surface of a MEMS device 410 to produce a thin sacrificial layer 412, and the MEMS device is soft-baked (420). Then, deep UV exposure (λ=248 nm) is performed (420) to pattern the thin sacrificial layer 412. The sacrificial layer 412 is bake-developed (430) at about 110° C. to decompose the exposed area, followed by encapsulation (440) of the sacrificial material using a photo-definable polymer overcoat Avatrel (Promerus, LLC) 414. After the encapsulation (440), the bond pads 416 are opened via photo-patterning (450) of the overcoat material 414. The sacrificial material under the overcoat that covers the MEMS structure is then thermally decomposed (460) at about 200-300° C. to create an air-cavity 418. This is the highest temperature step in this process. The by-products of thermal decomposition can easily diffuse out of the cavity 418 through the overcoat 414. An aluminum layer 417 can be sputtered (470) to hermetically seal the packaged MEMS device. After decomposition of the sacrificial material, the inside of the cavity 418 is clean of sacrificial material, and the device structure 419 is intact and free to move without any residue on the device. For example in one experimental trial, a 25 μm thick SOI beam resonator (2.6 MHz frequency) with a 1 μm gap was packaged via PVP with a Unity sacrificial material. The Unity sacrificial material is a photo-definable polycarbonate that has good adhesion to silicon, oxide, and metals and is thermally decomposable at low temperatures. Moreover, the Unity sacrificial material is characterized by clean decomposition in a narrow temperature range. In this trial, the Q-factor (Q=8000) did not change for this device after packaging and removal of the sacrificial material. Alternatively, FIG. 6 describes a packaging via dispensing (PVD) approach for applying the thermally decomposable sacrificial layer. This approach is more suitable to package bulk micromachined structures (e.g., HARPSS gyros/accelerometers) with fragile elements and wide and deep cavities (e.g., L>>g, where L represents the length of an air cavity 710 and g represents the width of a hole 720), as represented by FIG. 7. In this approach, thermally decomposable sacrificial material 610 (which does not have to be photo-definable) is applied (620) via a syringe dispensing tool (e.g., manually or automatically) with adjustable droplet size (e.g., 1 mm to 1 cm) to cover the air cavity 612. The sacrificial material 610 is then overcoated (630) using Avatrel overcoat material, and the process sequence continues similar to the PVP process, including a thermal release step (640) for decomposing the sacrificial layer 610 and a metallization step (650) for adding a metal barrier layer 617 over the air cavity 616. The final metallization step (650) enables a hermetically sealed package 618. The aforementioned processes are examples of techniques for applying a sacrificial material 105 and/or barrier materials 120 (e.g., overcoat materials, metal layers, other protective barriers, etc.) to MEMS devices. However, the present disclosure is not limited to the processes discussed with regard to FIGS. 4-7. For example, other lithography and etching techniques used in semiconductor fabrication processes may be used. As such, a MEMS device could also be packaged using a masked etching process on a thick sacrificial material which is aptly suited for packing small MEMS devices (e.g., HARPSS resonator, RF switch) with fragile elements or wide and deep holes (e.g., t>L>50 μm, where t represents the thickness of a sacrificial layer 810 and L is measures the length of an air cavity 820), as represented by FIG. 8. As such, an oxygen mask may be used to remove sacrificial material from undesired areas with an oxygen plasma. The feasibility of applying the aforementioned methods to package MEMS devices has been successfully verified. For example, a 15 μm thick 2.6 MHz SOI beam resonator (released) with 1 μm gap spacing, shown in FIG. 9A (with SCS beam and isolation trench noted), was packaged via PVP. Narrow trenches were etched down to the buried oxide to define the shape of the resonator and the sense/drive pads, followed by the removal of the buried oxide in HF solution. FIG. 9B shows the picture of the resonator after PVP. As shown, the resonator features a 15 μm tall cavity with a 20 μm thick overcoat layer. FIG. 9C shows the packaged resonator, after DC sputtering of gold to hermetically seal the device. In this device, the Avatrel overcoat was extended on top of isolation trenches. FIG. 9D shows the cross section of a broken packaged resonator (with SCS beam noted), showing a 15 μm tall, 80 μm wide cavity under a 20 μm thick Avatrel cap. In order to evaluate the PVD method, a 50 μm thick polysilicon HARPSS ring gyroscope with 1 μm gap and 200 μm deep cavity was fabricated, as shown in FIG. 10A. HARPSS sequence starts with patterning the nitride anchors and defining the trench. A thin layer of sacrificial oxide is deposited to uniformly cover the trench sidewalls and define the capacitive gap in between the SCS and polysilicon electrodes. Trenches are refilled with doped polysilicon to form the ring, springs, and the electrodes. Finally, the sensor is released in a DRIE tool, followed by removing the sacrificial oxide in HF solution. FIG. 10B shows the same device after manual dispensing of the sacrificial material. FIG. 10C is the view of the device after forming a thick (120 μm) overcoat cap and decomposing the sacrificial material from inside the cavity. FIG. 10D shows the device after breaking the 2 mm wide Avatrel capsule, confirming a very clean cavity and intact device structure (device is free to vibrate). The close-up view of the electrodes, the 1 μm capacitive gap, and the 4 μm wide polysilicon ring and support springs are shown in FIGS. 10E and 10F. This clearly shows that the sacrificial material can be decomposed through a very thick overcoat to create a stiff cap. It takes a few hours in room temperature before the air molecules can outgas through the Avatrel cap inside a vacuum chamber and the structure can start to resonate with high Q-factor. The packaged resonator of FIGS. 9A-9D was tested at wafer-level inside a vacuum probe station. A DC polarization voltage in the range of 70-80V was applied while the electrodes were directly connected to the network analyzer. FIG. 11A shows the frequency response of the resonator in vacuum before packaging and FIG. 11B shows the frequency response of the resonator in vacuum after packaging. The high Q-factor of approximately 5000 did not change for this device, proving that thermal decomposition of the Unity sacrificial material after packaging does not affect the performance of the device. As previously mentioned, a variety of MEMS device packages may be fabricated with varying levels of protection against environmental elements. Accordingly, examples of embodiments of MEMS packages include, but are not limited to, the following. In FIG. 12, one embodiment of a MEMS device package 1200 is shown In this embodiment, the MEFMS device package 1200 includes a substrate layer 1210, active region of MEMS device 1220, a vacuum packed air cavity region 1225, the contacts 1230, an overcoat layer 1240, and a barrier layer 1250. The package 1200 is fabricated by a process similar to that described with regard to the process of FIG. 2 where a sacrificial layer 325 has been removed to form the overcoat layer 1240 and barrier layer 1250 which may provide varying degrees of hermetic protection for the MEMS device. During this process, air inside the cavity 1225 was evacuated to produce a vacuum inside the cavity 1225, where the metal barrier 1250 prevents air from entering the air cavity region 1225. By converting the sacrificial material 325 to a gaseous material that permeates the overcoat layer 1240, the cavity 1225 is free of residue, including any residual sacrificial material. Correspondingly, the overcoat layer 1240 is also free of residue and maintains structural integrity, since perforations were not drilled into the overcoat layer to remove any sacrificial material. The MEMS package 1200 may be connected to external points or undergo further packaging by a variety of methods, including wirebond technology, flip-chip technologies, utilizing leadframe packaging, surface mount packaging, ceramic packaging, or other high performance techniques, as is described hereinafter. A particular processing technique available for a MEMS device may be dependent upon the level of protection offered by the overcoat and barrier layers, since different processing techniques exert different amounts of pressure and rigors on microelectronic devices. Referring now to FIG. 13, another embodiment of a MEMS package 1300 is shown. In FIG. 13, the MEMS device package 1300 includes a substrate layer 1310, active surface of a MEMS device 1320, an air cavity 1325 surrounding the active surface of the MEMS device, the contacts 1330, an overcoat layer 1340, and a barrier layer 1350. The package 1300 is fabricated by a process similar to that process described with regard to FIG. 2 where a sacrificial layer 325 has been removed to form the overcoat layer 1340 and barrier layer 1350. However, for this embodiment, the process of forming a vacuum inside the air cavity 1325 is not performed, since there are many MEMS devices that do not require vacuum packing. As such, the barrier layer 1350 may still prevent air and moisture from entering the air cavity region 1325 encapsulated by the barrier layer 1350 (e.g., a metal layer). Further, by converting the sacrificial material 325 to a gaseous material that permeates the overcoat layer 1340, the air cavity 1325 is free of residue, including any residual sacrificial material. Correspondingly, the overcoat layer 1340 is also free of residue and maintains structural integrity, since perforations were not drilled into the overcoat layer to remove any sacrificial material. The MEMS device package 1300 may be connected to external points by a variety of methods, including wirebond technology, flip-chip technologies, utilizing leadframe packaging, surface mount packaging, ceramic packaging, or other high performance techniques, as is described hereinafter. A particular processing technique available for a MEMS device may be dependent upon the level of protection offered by the overcoat and barrier layers, since different processing techniques exert different amounts of pressure and rigors on microelectronic devices. In another embodiment, FIG. 14 shows a MEMS device package 1400 with a substrate layer 1410, an active surface of MEMS device 1420, an air cavity region 1425 around the active surface of MEMS device, the contacts 1430, and an overcoat layer 1440 that also serves as a protective layer. This package 1400 is fabricated by a process similar to a portion of the process that is described with regard to FIG. 2 where a sacrificial layer 325 has been removed to form the overcoat layer 1440. However, in this example, the package 1400 is complete after the sacrificial layer 325 has been removed (230) and the overcoat layer 1440 remains. Accordingly, as part of adding (220) the overcoat layer, the overcoat material is generally baked in order to make the overcoat rigid and hard, which may serve as adequate protection against external forces for many applications and types of MEMS devices. Moreover, by converting the sacrificial material 325 to a gaseous material that permeates the overcoat layer 1440, the air cavity 1425 is free of residue, including any residual sacrificial material. Correspondingly, the overcoat layer 1440 is also free of residue and maintains structural integrity, since perforations were not drilled into the overcoat layer to remove any sacrificial material. The MEMS device package 1400 may be connected to external points by a variety of methods, including wirebond technology, flip-chip technologies, utilizing leadframe packaging, surface mount packaging, ceramic packaging, or other high performance techniques, depending upon the particular qualities of the packaging processes and the protection requirements of particular MEMS devices. Referring now to FIG. 15, another embodiment of a MEMS device package 1500 is shown. In this embodiment, the MEMS device package 1500 includes a substrate layer 1510, an active surface of MEMS device 1520, an air cavity 1525 surrounding the active surface of the MEMS device, the contacts 1530, and a sacrificial layer 1540. The package 1500 is fabricated by a process similar to a portion of the process described with regard to FIG. 2 where a sacrificial material has been applied to form a sacrificial layer 325. However, in this particular example, the process is completed after the step of adding the sacrificial layer has been performed (210). Accordingly, as part of adding the sacrificial layer, the sacrificial material is encased around the active surface of a MEMS device 1520, which may serve as adequate protection against external forces before the MEMS device package is subsequently attached to external points or terminals by current wirebonding techniques and/or surface mounting practices. After packaging of the MEMS device, the MEMS device package may not only resemble an integrated circuit (e.g., it has wire bond pads, a coated surface, etc.), but may also be treated like many integrated circuits and may be packaged like many integrated circuits. For example, consider the following process for attaching a MEMS device to a support structure, such as a metal frame traditionally used for mounting integrated circuits (e.g., leadframe). As described in FIG. 16, a process for attaching a MEMS device 1500 having a sacrificial layer 1540 surrounding a MEMS device is discussed. Accordingly, a leadframe (1600) is provided. In this example, a thin metal sheet (e.g., Copper) is processed into a leadframe 1600 having a die pad 1610 for attaching a microelectronic device package and lead fingers 1620 for connecting wires to bond pads or contacts on the microelectronic device. Correspondingly, a MEMS device package 1630 having a sacrificial layer 1540 is attached (1625) to the leadframe 1600 (by mounting or bonding the package 1630 to the die pad 1610 of the leadframe 1600). Further, metal wires 1640 are connected (1625) from the lead fingers 1620 or terminals of the leadframe 1600 and the bond pads or contacts 130 of the MEMS device package 1630. Then, a coating material 1650 (e.g., plastic molding compounds, thermosetting polymers, epoxy resin, etc.) is applied (1645) to the surface of the MEMS device package and a portion of the leadframe 1600 as part of a molding process. The coating material 1650 used in this process has a curing temperature that is lower than the temperature for thermal decomposition of the sacrificial material 1540 in the MEMS device package 1500. Thus, the coating material 1650 is cured at a lower temperature (that is less than the temperature for thermal decomposition of the sacrificial material) to harden the coating material. The coating material 1650 includes the characteristic of being permeable or semi-permeable to the decomposition gases produced by the decomposition of a sacrificial polymer of the sacrificial layer 1540. The coating material 1650 serves to provide a moisture-resistive material over the surface of the MEMS device and lead frame assembly or “chip” for the purpose of minimizing package stresses on the surface of the chip and provide additional protection against corrosion. This is a standard step in low-cost microelectronic packaging of integrated circuits. However, with MEMS devices, such as step would typically negatively interfere and harm the workings of a MEMS structure that does not have a protective covering. Accordingly, with the presence of the sacrificial layer 1540, the coating 1650 is not in contact with the active surface of the MEMS device. After the coating 1650 has cured and is hardened, the MEMS chip is then baked at a temperature that exceeds the thermal decomposition of the sacrificial material. After which, the sacrificial material is converted into a gaseous state and permeates or diffuses through the coating material 1650. After decomposition of the sacrificial layer, an air cavity is formed around the active surface of the MEMS device, and the coating material 1650 now serves as a protective layer to prohibit elements from entering the air cavity and to protect the MEMS device, in general. The MEMS “chip” 1660 is then removed (1655) from the leadframe via a singulation process and the leads of chip are bent into a desired shape, as part of standard chip packaging process. A process, as just described, has worked well in thin epoxy packages (such as TSOP (thin small outline package) and TQFP (thin quad flat package). However, the process is not limited to thin epoxy coatings and may also work with other coating variants. Further, other embodiments of the MEMS device package may also be employed in a similar process. For example, for one embodiment (as represented by FIG. 14), the MEMS device package includes an overcoat layer 1440 that provides additional support for the MEMS device without affecting the thermal decomposition of a sacrificial material 1425. Thus, such a MEMS device package may also be added to a leadframe using the process described in FIG. 16. Additionally, in other embodiments (as represented by FIGS. 12 and 13), MEMS device packages may not include a sacrificial layer and alternatively, includes additional support structures, such as a barrier level 1250, 1350. As such, these MEMS device package will not need to baked at a temperature exceeding the curing temperature of the coating material, since a sacrificial material is not present. Otherwise, the process described in FIG. 16 may be used to further package such MEMS device packages using common integrated circuit packaging processes (e.g., leadframe packaging). According to the present disclosure, some embodiments of the micro electro-mechanical device packages generally include one or more MEMS devices; interconnection from the device(s) to the package; a surrounding or containing structure to provide both mechanical and electrical, chemical, and environmental protection; and a joining structure to attach the package to a circuit board or system. Such embodiments provide a versatile packaging process at a wafer-level for MEMS devices that is generally applicable to package devices fabricated by different processes for various applications. Accordingly, embodiments of the present disclosure are capable of adapting to well-developed integrated circuit packaging technologies, as demonstrated in FIG. 17. Referring now to FIG. 17, a MEMS device package 1710 of the present disclosure can be produced to meet an assortment of packaging requirements and preferences. For example, a MEMS device package 1710 can be packaged to provide varying levels or degrees of hermetic protection for a MEMS device. As shown in FIG. 17, hermetic protection levels include, but is not limited to, mechanical protection 1720 (e.g., from inadvertent touching, further packaging, etc.), protection from oxygen and water in addition to mechanical protection 1730, and protection from all exposure to all gases (e.g., have a pure vacuum) in addition to mechanical protection 1740. In addition to varying degrees of hermetic protection, a MEMS device package 1710 can also utilize a variety of bonding techniques to provide electrical connections to external points or terminals. Such bonding techniques include, but are not limited to, wire bonding techniques 1750 and flip chip bonding techniques 1760. Moreover, a MEMS device package 1710 of the present disclosure can be further utilized in a variety of microelectronic device packaging techniques that are already in common use. For example, a MEMS device package may utilize common integrated circuit techniques that include, but are not limited, to low cost plastic packaging techniques 1770 and ceramic or other high performance packaging techniques 1780. For either of these approaches, additional packaging technologies are also available including, but not limited to, surface mount processes 1790 and through-hole mounting processes 1795. Advantageously, embodiments of the present disclosure provide a variety of improved approaches for protecting MEMS devices. For example, in accordance with the present disclosure, a sacrificial layer on a MEMS device may be removed without perforating an overcoat layer surrounding the sacrificial layer and active structures of a MEMS device. Further, the thickness of the overcoat layer and/or barrier layer may be adjusted or tailored (e.g., between range of 50 nm and 500 μm) to withstand external pressures or pressures encountered during packaging processes and provide adequate protection for a MEMS device. For example, the overcoat layer can be spin-coated at a different speed or the viscosity of the overcoat material may be changed to adjust the thickness of the overcoat layer that is formed on a MEMS device. Therefore, the thickness of the overcoat material could be made as thick as reasonably necessary (e.g., 5 cm). Advantageously, embodiments of the present disclosure may also provide a protective layer on any substrate material, since the sacrificial and overcoat materials are polymer substances and have good thermal mismatch characteristics with common substrate materials which does not result in deformations in MEMS structures. Additionally, there are a wide variety of sacrificial materials that can be employed in accordance with the present disclosure within a wide range of thermal decomposition temperatures. Thus, a desired thermal decomposition temperature can be selected (e.g., from 80° C. to 400° C.), and based upon the selected temperature, a sacrificial material can be chosen. Accordingly, decomposition time and temperature may be optimized for each application according to overcoat thickness. Further, sacrificial materials can be chosen based on whether a photosensitive sacrificial material is desired or not. It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiment(s) of the disclosure without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure.
|
H
|
H01
|
H01L
|
23
|
20
|
|||
11795168
|
US20080118029A1-20080522
|
X-Ray Facility with Error Protection Circuit
|
ACCEPTED
|
20080509
|
20080522
|
[]
|
H05G154
|
["H05G154"]
|
7778390
|
20070712
|
20100817
|
378
|
117000
|
99394.0
|
SONG
|
HOON
|
[{"inventor_name_last": "Schliermann", "inventor_name_first": "Claus-Gunter", "inventor_city": "Kemnath", "inventor_state": "", "inventor_country": "DE"}]
|
The invention relates to a residual-current circuit breaker for an X-ray device. In one embodiment, the residual-current circuit breaker comprises at least one input, via which a detector identification signal of a detector identification element can be received, said signal characterizing the presence of an X-ray detector and at least one input, via which a selection signal for an exposure measurement element can be received, said signal characterizing the activation of an exposure measurement element. A deactivation signal can be issued via at least one output of the residual-current breaker, the deactivation signal being generated as long as a detector identification signal and a selection signal that is assigned to the same detector as the detector identification signal are not received at the same time.
|
1. An error protection circuit for an x-ray facility comprising: a first input that is operable to receive a detector identification signal of a detector identification element, said detector identification signal characterizing the presence of an x-ray detector, a second input that is operable to receive a selection signal for an exposure measurement element, said selection signal characterizing the activation of the exposure measurement element, and with an output that is operable to emit a deactivation signal, the deactivation signal being generated on the basis that a detector identification signal and a selection signal assigned to the x-ray detector as the detector identification signal are not received at the same time. 2. The error protection circuit as claimed in claim 1, wherein the deactivation signal is generated on the basis that a detector identification signal and no selection signal assigned to the same detector as the detector identification signal is received. 3. The error protection circuit as claimed in claim 1 or 2, wherein the deactivation signal is generated on the basis that a selection signal and no detector identification signal assigned to the same detector as the selection signal is received. 4. The error protection circuit as claimed in claim 1, wherein the deactivation signal is received by an x-ray generators. 5. The error protection circuit as claimed in claim 4, wherein the deactivation signal is received by an input of the x-ray generator provided for deactivation signals. 6. An x-ray facility with at least one image receiver, comprising: at least one detector identification element that is operable to generate a detector identification signal, said signal characterizing the presence of an x-ray detector, and at least one exposure measurement element, which can be activated by a selection signal generated by the x-ray facility, and an error protection circuit. 7. The x-ray facility as claimed in claim 6, wherein the error protection circuit includes: a first input that is operable to receive a detector identification signal of a detector identification element, said detector identification signal characterizing the presence of an x-ray detector, a second input that is operable to receive a selection signal for an exposure measurement element, said selection signal characterizing the activation of the exposure measurement element, and an output that is operable to emit a deactivation signal, the deactivation signal being generated on the basis that a detector identification signal and a selection signal assigned to the x-ray detector as the detector identification signal are not received at the same time. 8. The error protection circuit as claimed in claim 1, comprising a plurality of detectors. 9. The error protection circuit as claimed in claim 1, comprising a plurality of inputs operable to receive different detector identification signals of the detector identification element. 10. The error protection circuit as claimed in claim 1, comprising a plurality of inputs operable to receive different selection signals. 11. The error protection circuit as claimed in claim 1, comprising a plurality of outputs operable to emit different deactivation signals. 12. The error protection circuit as claimed in claim 5, wherein the input of the x-ray generator is provided for a door contact signal.
|
<SOH> BACKGROUND <EOH>The present embodiments relate to an error protection circuit for an x-ray facility and an x-ray facility with such an error protection circuit. Error protection circuits prevent the emission of high radiation doses due to operating errors. X-ray facilities have at least one image receiver. The image receiver records x-ray images of a patient or body to be examined, which is fluoroscopically examined by the x-ray radiation of an x-ray emitter. The image receiver has a cassette drawer in the case of cassette recording points. A cassette-type x-ray detector is inserted in the cassette drawer. The x-ray detector can, for example, be an x-ray film cassette. The cassette drawer also has an exposure measurement chamber, which is used to set automatic exposure times. The exposure measurement chamber measures the radiation dose occurring at the x-ray detector and triggers a disconnect signal for the x-ray emitter when a predetermined measurement value is reached. Cassette drawers and other image receivers can be disposed, for example, on patient support tables, on C-arms, floor gantries or ceiling gantries. Further possibilities for the arrangement of image receivers are conceivable. Depending on which x-ray recording points are to be realized, x-ray facilities have one or more image receivers. To produce an x-ray recording, an x-ray detector has to be inserted into the respective image receiver and the x-ray emitter has to be oriented toward the image receiver. Operator errors can occur because an x-ray detector does not have to be inserted into every image receiver and it does not have to be possible to identify from outside whether an x-ray detector is inserted. The x-ray emitter can be switched on, even though there is no x-ray detector inserted into the corresponding image receiver. The radiation dose administered to the patient is a pointless load on the examined patient or body, since no x-ray recording can be produced without an x-ray detector. X-ray facilities with a number of image receivers require inserting the x-ray detector and activating an exposure measurement chamber assigned to the x-ray detector. It is possible that an x-ray detector is inserted into the correct image receiver but the exposure measurement chamber assigned to the x-ray detector has not been activated. Possibly an operator erroneously selects the wrong image receiver, even though they have inserted the x-ray detector into the correct image receiver. If an x-ray recording is then initiated using an automatic exposure unit, very high radiation exposure results and the erroneously selected exposure measurement chamber does not receive any x-ray radiation. The x-ray radiation strikes the exposure measurement chamber of the correct but not selected image receiver. If the selected exposure measurement chamber does not receive a radiation dose however, it also does not generate a disconnect signal for the x-ray emitter, since the dose limit value is not reached. To avoid unnecessary radiation exposure due to such operating errors, the exposure measurement chamber signal can be observed while the x-ray recording is being produced. If after a predetermined time the measurement chamber signal is below a minimum value, incorrect operation is assumed and the x-ray recording is aborted. However, modern image receivers are so sensitive that the predetermined minimum value has to be set extremely low. The minimum value is exceeded simply by the scattered radiation occurring at the exposure measurement chamber and the x-ray recording is therefore not aborted. In the case of x-ray facilities with a central device controller, the production of an x-ray recording is only initiated when an x-ray detector is inserted in the selected image receiver. It is only necessary to provide a detector identification, identifying the presence of an x-ray detector, in the image receiver. However, simple, manual x-ray facilities generally do not have a central controller. DE 200 13 478 U1 discloses a solution for checking whether an x-ray detector is inserted in the image receiver and whether the grid contact of the image receiver is closed. A grid contact is used with image receivers, which have a moving scattered radiation grid. The solution disclosed in DE 200 13 478 U1 is not suitable for image receivers without or with a fixed scattered radiation grid.
|
<SOH> SUMMARY <EOH>The present embodiments may obviate one or more of drawbacks or limitations of the prior art. For example, one of the present embodiments prevents high radiation exposures due to operating errors in a manner that is as economical as possible and can be used in many different ways. In one embodiment, an error protection circuit includes at least one input, by way of which a detector identification signal of a detector identification element can be received. The detector identification signal characterizing the presence of an x-ray detector. At least one input, by way of which a selection signal for an exposure measurement element can be received. The selection signal characterizing the activation of an exposure measurement element. At least one output, by way of which a deactivation signal can be emitted. The deactivation signal generated as a function of receipt of a detector identification signal and a selection signal assigned to the same detector as the detector identification signal. The selection signal indicates which image receiver has been selected, while the detector identification signal indicates whether an x-ray detector has actually been inserted in the selected image receiver. The error protection circuit prevents an error situation, in which someone has forgotten to insert a detector. The error protection circuit reliably identifies an error situation, in which an x-ray detector has been inserted into the correct image receiver, but the wrong image receiver has been activated. A signal that is available anyway in the x-ray facility is used with the selection signal for the exposure measurement element as the signal for identifying which image receiver is to be used. No other modification of the x-ray facility is required for this. The signal of a detector identification element is used as the signal for identifying whether an x-ray detector is inserted. If the image receiver does not make such a signal available anyway, a corresponding sensor or contact can be realized with little outlay. The error protection system has a logic or logical circuit, which links the detector identification signal to the selection signal, to form the deactivation signal. The logical link includes linking the detector identification signal and the selection signal for the same image receiver, such that a deactivation signal is generated, if both input signals are not positive. The deactivation signal can be used by the x-ray facility to prohibit the generation of x-ray radiation. In one embodiment, the deactivation signal is generated if a detector identification signal is received but the selection signal assigned to the same detector as the detector identification signal is not received. This deactivation signal status indicates that an x-ray detector is inserted but the wrong image receiver has been selected. In one embodiment, the deactivation signal is generated if a selection signal is received but the detector identification signal assigned to the same detector as the selection signal is not received. This deactivation signal status indicates that the right image receiver was selected but someone forgot to insert an x-ray detector. In one embodiment, the deactivation signal is received by an x-ray generator. The error protection circuit can prohibit the production of an x-ray recording by preventing the x-ray generator applying an x-ray voltage to the x-ray emitter. This prevents the generation of x-ray radiation in a direct manner without involving error-prone means. In one embodiment, the deactivation signal is received by way of an input of the x-ray generator provided for deactivation signals, for example, for contact signals. The error protection circuit only has to be connected to an input of the x-ray generator, which is generally present anyway. The input for a door contact signal is generally present, to prevent the initiation of x-ray recordings while the door to the control space containing the x-ray controller is not closed. This protects operators from unnecessary radiation exposure. No modification of the x-ray generator is required because inputs of the x-ray generator that are present are utilized. This makes it possible, for example, to retrofit the error protection circuit easily in already installed x-ray facilities. In one concept, an x-ray facility with at least one image receiver includes at least one detector identification element. A detector identification signal can be generated by the at least one detector identification element. The detector identification signal characterizes the presence of an x-ray detector. The x-ray facility includes at least one exposure measurement element, which can be activated by a selection signal generated by the x-ray facility. The x-ray facility includes an error protection circuit as described above.
|
The present patent document is a nationalization of PCT Application Serial Number PCT/EP2006/050128, filed Jan. 10, 2006, designating the United States, which is hereby incorporated by reference. The present patent document also claims the benefit of DE 10 2005 002 559.5, filed Jan. 19, 2005. BACKGROUND The present embodiments relate to an error protection circuit for an x-ray facility and an x-ray facility with such an error protection circuit. Error protection circuits prevent the emission of high radiation doses due to operating errors. X-ray facilities have at least one image receiver. The image receiver records x-ray images of a patient or body to be examined, which is fluoroscopically examined by the x-ray radiation of an x-ray emitter. The image receiver has a cassette drawer in the case of cassette recording points. A cassette-type x-ray detector is inserted in the cassette drawer. The x-ray detector can, for example, be an x-ray film cassette. The cassette drawer also has an exposure measurement chamber, which is used to set automatic exposure times. The exposure measurement chamber measures the radiation dose occurring at the x-ray detector and triggers a disconnect signal for the x-ray emitter when a predetermined measurement value is reached. Cassette drawers and other image receivers can be disposed, for example, on patient support tables, on C-arms, floor gantries or ceiling gantries. Further possibilities for the arrangement of image receivers are conceivable. Depending on which x-ray recording points are to be realized, x-ray facilities have one or more image receivers. To produce an x-ray recording, an x-ray detector has to be inserted into the respective image receiver and the x-ray emitter has to be oriented toward the image receiver. Operator errors can occur because an x-ray detector does not have to be inserted into every image receiver and it does not have to be possible to identify from outside whether an x-ray detector is inserted. The x-ray emitter can be switched on, even though there is no x-ray detector inserted into the corresponding image receiver. The radiation dose administered to the patient is a pointless load on the examined patient or body, since no x-ray recording can be produced without an x-ray detector. X-ray facilities with a number of image receivers require inserting the x-ray detector and activating an exposure measurement chamber assigned to the x-ray detector. It is possible that an x-ray detector is inserted into the correct image receiver but the exposure measurement chamber assigned to the x-ray detector has not been activated. Possibly an operator erroneously selects the wrong image receiver, even though they have inserted the x-ray detector into the correct image receiver. If an x-ray recording is then initiated using an automatic exposure unit, very high radiation exposure results and the erroneously selected exposure measurement chamber does not receive any x-ray radiation. The x-ray radiation strikes the exposure measurement chamber of the correct but not selected image receiver. If the selected exposure measurement chamber does not receive a radiation dose however, it also does not generate a disconnect signal for the x-ray emitter, since the dose limit value is not reached. To avoid unnecessary radiation exposure due to such operating errors, the exposure measurement chamber signal can be observed while the x-ray recording is being produced. If after a predetermined time the measurement chamber signal is below a minimum value, incorrect operation is assumed and the x-ray recording is aborted. However, modern image receivers are so sensitive that the predetermined minimum value has to be set extremely low. The minimum value is exceeded simply by the scattered radiation occurring at the exposure measurement chamber and the x-ray recording is therefore not aborted. In the case of x-ray facilities with a central device controller, the production of an x-ray recording is only initiated when an x-ray detector is inserted in the selected image receiver. It is only necessary to provide a detector identification, identifying the presence of an x-ray detector, in the image receiver. However, simple, manual x-ray facilities generally do not have a central controller. DE 200 13 478 U1 discloses a solution for checking whether an x-ray detector is inserted in the image receiver and whether the grid contact of the image receiver is closed. A grid contact is used with image receivers, which have a moving scattered radiation grid. The solution disclosed in DE 200 13 478 U1 is not suitable for image receivers without or with a fixed scattered radiation grid. SUMMARY The present embodiments may obviate one or more of drawbacks or limitations of the prior art. For example, one of the present embodiments prevents high radiation exposures due to operating errors in a manner that is as economical as possible and can be used in many different ways. In one embodiment, an error protection circuit includes at least one input, by way of which a detector identification signal of a detector identification element can be received. The detector identification signal characterizing the presence of an x-ray detector. At least one input, by way of which a selection signal for an exposure measurement element can be received. The selection signal characterizing the activation of an exposure measurement element. At least one output, by way of which a deactivation signal can be emitted. The deactivation signal generated as a function of receipt of a detector identification signal and a selection signal assigned to the same detector as the detector identification signal. The selection signal indicates which image receiver has been selected, while the detector identification signal indicates whether an x-ray detector has actually been inserted in the selected image receiver. The error protection circuit prevents an error situation, in which someone has forgotten to insert a detector. The error protection circuit reliably identifies an error situation, in which an x-ray detector has been inserted into the correct image receiver, but the wrong image receiver has been activated. A signal that is available anyway in the x-ray facility is used with the selection signal for the exposure measurement element as the signal for identifying which image receiver is to be used. No other modification of the x-ray facility is required for this. The signal of a detector identification element is used as the signal for identifying whether an x-ray detector is inserted. If the image receiver does not make such a signal available anyway, a corresponding sensor or contact can be realized with little outlay. The error protection system has a logic or logical circuit, which links the detector identification signal to the selection signal, to form the deactivation signal. The logical link includes linking the detector identification signal and the selection signal for the same image receiver, such that a deactivation signal is generated, if both input signals are not positive. The deactivation signal can be used by the x-ray facility to prohibit the generation of x-ray radiation. In one embodiment, the deactivation signal is generated if a detector identification signal is received but the selection signal assigned to the same detector as the detector identification signal is not received. This deactivation signal status indicates that an x-ray detector is inserted but the wrong image receiver has been selected. In one embodiment, the deactivation signal is generated if a selection signal is received but the detector identification signal assigned to the same detector as the selection signal is not received. This deactivation signal status indicates that the right image receiver was selected but someone forgot to insert an x-ray detector. In one embodiment, the deactivation signal is received by an x-ray generator. The error protection circuit can prohibit the production of an x-ray recording by preventing the x-ray generator applying an x-ray voltage to the x-ray emitter. This prevents the generation of x-ray radiation in a direct manner without involving error-prone means. In one embodiment, the deactivation signal is received by way of an input of the x-ray generator provided for deactivation signals, for example, for contact signals. The error protection circuit only has to be connected to an input of the x-ray generator, which is generally present anyway. The input for a door contact signal is generally present, to prevent the initiation of x-ray recordings while the door to the control space containing the x-ray controller is not closed. This protects operators from unnecessary radiation exposure. No modification of the x-ray generator is required because inputs of the x-ray generator that are present are utilized. This makes it possible, for example, to retrofit the error protection circuit easily in already installed x-ray facilities. In one concept, an x-ray facility with at least one image receiver includes at least one detector identification element. A detector identification signal can be generated by the at least one detector identification element. The detector identification signal characterizes the presence of an x-ray detector. The x-ray facility includes at least one exposure measurement element, which can be activated by a selection signal generated by the x-ray facility. The x-ray facility includes an error protection circuit as described above. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an x-ray facility with a number of image receivers, FIG. 2 illustrates an x-ray generator with image receivers and an error protection circuit; and FIG. 3 illustrates a logical linking operation within the error protection circuit. DETAILED DESCRIPTION FIG. 1 illustrates an x-ray facility, by means of which different x-ray recording points can be realized. An x-ray recording point here refers to a specific body position of the patient to be examined with associated orientation of the x-ray emitter and image receiver. In one embodiment, as shown in FIG. 1, the x-ray facility has an x-ray emitter 6, which is supported in a C-arm 1 so that it can be rotated about a horizontal axis 7. An image receiver 8 is supported in the C-arm 1. The C-arm 1 is supported in a ceiling gantry 4 so that it can be rotated about a horizontal axis 5. The ceiling gantry 4 has possibilities for vertical displacement, rotation, and horizontal travel. The horizontal travel is illustrated by a double arrow 2. The x-ray facility includes a patient bed 12, supported on a base standing on the floor of the examination room. An image receiver 11 is disposed below the patient bed 12. The image receiver 11 is a cassette drawer, which can be pulled out in the manner of a conventional drawer below the patient bed 11, to insert or remove an x-ray detector, for example. To utilize an x-ray recording point using the image receiver 11, the C-arm 1 is oriented so that the x-ray emitter 6 is oriented toward the image receiver 11. The x-ray facility includes a floor gantry 15. The floor gantry 15 holds an image receiver 14. The image receiver 14 produces x-ray recordings at the standing patient, to which end the x-ray emitter 6 is also correspondingly oriented. To produce an x-ray recording, an operator must position the patient, insert an x-ray detector into the required image receiver 8, 11, 14 and activate the image receiver 8, 11, 14, by selecting the respective exposure measurement chamber. In one embodiment, as shown in FIG. 2, an x-ray generator 30 includes an error protection circuit 31 and image receivers 40, 50. In FIG. 2, the corresponding signal connections are symbolized by arrow lines. The x-ray generator 30 includes an input 39 for a deactivation signal. If the x-ray generator 30 receives a positive deactivation signal by way of the input 39, generation of an x-ray voltage is prohibited. Prohibiting the generation of x-ray voltage, as required to operate an x-ray emitter, directly prevents the generation of x-ray radiation. The input 39 can, for example, be the signal input for a door contact. The image receivers 40, 50 include detector detection elements 42, 52, to identify the respective presence of an x-ray detector. The detector detection elements 42, 52 generate a positive signal, if an x-ray detector is inserted. The detector detection elements 42 emit this signal to corresponding inputs 34, 36 of the error protection circuit 31. The image receivers 40, 50 also include exposure measurement elements with measurement fields 45, 46, 47, 55, 56, 57. The exposure measurement elements or their measurement fields are activated by a respective selection signal, which is generated by the x-ray generator 30. The respective selection signal activates at least one measurement field 45, 46, 47, 55, 56, 57 of the image receiver 40, 50, which is to be used to produce an x-ray recording. The selection signal goes to the error protection circuit 31 and to the image receivers 40, 50 by way of corresponding inputs 35, 37. The error protection circuit 31 has a logic, which links the input signals to the inputs 34, 35, 36, 37 as described below. If the presence of a cassette in the image receiver 40 is detected by the detector detection element 42, at least one of the exposure measurement elements 45, 46, 47 must be selected at the same time, so that no deactivation signal is generated. The selection signals for the exposure measurement elements 45, 46, 47 are therefore OR-linked. The result of the OR operation is AND-linked to the signal of the detector detection element 42. The result of the AND linking operation is inverted, to obtain the deactivation signal. A positive signal indicates that the x-ray detector is present, and an exposure measurement element is selected and respectively the deactivation signal is active. It would be possible to invert the significance of the respective signal, and this would have to be taken into account by a corresponding change to the described logical linking operations. Corresponding changes, however, result from the effect of the described logic, so are not described in more detail here. If neither a signal of the detector detection element 42 nor a signal of one of the exposure measurement elements 45, 46, 47 is generated in the image receiver 40, the described logical linking of the signals similarly leads to the generation of the deactivation signal. The signals of the image receiver 50 are linked in the same manner as the signals of the image receiver 40. Based on a linking of the logical signals, obtained from the individual signals of both image receivers 40, 50, it is possible to identify further incorrect operation situations. If the signal status of both image receivers 40, 50 results in the generation of the deactivation signal, this should actually be generated. If however the signal status of both image receivers 40, 50 results respectively in the suppression of the deactivation signal, it is assumed that both image receivers 40, 50 have been selected and an x-ray detector has been inserted erroneously in each instance. The simultaneous use of both image receivers 40, 50 can however in principle be excluded, since an x-ray emitter can only be oriented toward one of the image receivers. To prevent this incorrect operation situation, the signals for the two image receivers 40, 50 are OR-linked and then inverted. As a result of this linking operation the deactivation signal is only suppressed, if just one image receiver 40, 50 is selected and an x-ray detector is inserted. FIG. 3 shows the described logical link operations in a schematic manner. These linking operations can be extended to take into account further input variables. Changes can be made to adjust to modified incorrect operation situations. In the selected schematic diagram “≧1” means a logical (Boolean) OR operation, “&” means a logical AND operation and “Inv” means a logical inversion (the signal value “1” is inverted to “0” and vice versa). In one embodiment, the logical signal “1” at the signal input 34 indicates the presence of an x-ray detector. The logical signal “1” at one of the signals inputs 35 indicates the activation of an exposure measurement element assigned to the x-ray detector. As a result of the OR operation 60, the logical signal “1” is then present. The two signals “1” are linked by the AND operation 61 to the logical signal “1.” The subsequent inversion 62 gives the logical signal “0” for this half-side of the overall logic. The logical signal “1” at the signal input 34 indicates the presence of an x-ray detector. However, the logical signal “0” at the signal inputs 35 indicates that none of the exposure measurement elements assigned to the detector have been activated. There is therefore an error situation, where an x-ray detector has been inserted but no associated exposure measurement elements have been activated. The OR operation 70 then results in the logical signal “0.” The signals are linked by the AND operation 71 to the logical signal “0.” The subsequent inversion 72 gives the logical signal “1” for this half-side of the overall logic. The logical signal “1” as a result of the inversion 72 results, irrespective of the signal situation of the other half-side of the overall logic, in the OR operation 80 resulting in the logical signal “1.” This is generated at the signal output 38 of the error protection circuit 31. The logical signal “1” at the signal output 38 has the same significance as the generation of the deactivation signal by the error protection circuit 31. The present embodiments can be summarized as follows. The present embodiments relate to an error protection circuit 31 for an x-ray facility. In one exemplary embodiment, the error protection circuit 31 includes at least one input 34, 36, by way of which a detector identification signal of a detector identification element 42, 52 can be received. The detector identification signal characterizing the presence of an x-ray detector. The x-ray facility includes at least one input 35, 37, by way of which a selection signal for an exposure measurement element 45, 46, 47, 55, 56, 57 can be received. The selection signal characterizing the activation of an exposure measurement element 45, 46, 47, 55, 56, 57. A deactivation signal can be emitted by way of at least one output 38 of the error protection circuit 31. The deactivation signal generated on the basis that a detector identification signal and a selection signal assigned to the same detector as the detector identification signal are not received at the same time. While the invention has been described above by reference to various embodiments, it should be understood that many changes and modifications can be made without departing from the scope of the invention. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to define the spirit and scope of this invention.
|
H
|
H05
|
H05G
|
1
|
54
|
|||
11921431
|
US20090121629A1-20090514
|
Controllable Gas-Discharge Device
|
ACCEPTED
|
20090429
|
20090514
|
[]
|
H01J1704
|
["H01J1704"]
|
7825595
|
20071129
|
20101102
|
313
|
581000
|
75519.0
|
HADERLEIN
|
PETER
|
[{"inventor_name_last": "Bochkov", "inventor_name_first": "Viktor Dmitrievich", "inventor_city": "Ryazan", "inventor_state": "", "inventor_country": "RU"}]
|
The invention relates to controllable powerful cold-cathode gas-discharge devices or pseudospark switches intended for rapidly switching high-current high-voltage circuits, which can be used in different pulse devices. The inventive cold-cathode gas-discharge device comprises an anode, a hollow cathode which is separated therefrom by a main discharge gap and whose base is oriented thereto, wherein said base is provided with openings embodied therein for coupling the main discharge gap to a trigger electrode which is arranged in the cathode cavity and is provided with an igniter made of a polycrystal semiconductor material based on a semiconductor whose energy gap is larger than 1.5 eV, the device comprises at least two contacting electrodes contacting with the igniter, wherein at least one electrode is connected to the trigger electrode, whereas the other is insulated therefrom and connected to the cathode, the maximum width of the contacting electrode in the cross-section thereof across a point where it is brought into contact with the igniter is equal to or less than 100 times the average pitch of roughness value on the igniter surface.
|
1. A controllable gas-discharge device, comprising an anode, a hollow cathode, which is separated therefrom by a main discharge gap and whose base is oriented thereto; said base is provided with openings embodied therein for coupling the main discharge gap to a trigger electrode which is arranged in the cathode cavity and is provided with an igniter made of a polycrystal semiconductor material, wherein the igniter is made of polycrystal material based on a semiconductor whose energy gap is larger than 1.5. The device contains at least one electrode which is connected to the trigger electrode, whereas the other is insulated therefrom and connected to the cathode, the maximum width of the contacting electrode in the cross-section thereof across a point where it is brought into contact with the igniter is equal to or less than 100 times the average pitch of roughness value on the igniter surface. 2. The switch of claim 1 wherein said igniter is made of polycrystal material on basis of a semiconductor with non-linear voltage-current characteristic and threshold voltage not more than 5 kv. 3. The switch of claim 1 or 2 wherein said polycrystal material of the igniter consists of granules of the base semiconductor material with gaps among them, filled with a polycrystal or a dielectric binding material. 4. The switch of claim 1 or 2 wherein the distance between contacting electrodes is 1-5 mm, the points of contact with the igniter are placed on the upper part of the igniter so as to provide direct visibility of said contacts in the direction of cathode base, whereas to eliminate breakdown in other directions said igniter is placed into a focusing screen. 5. The switch of claim 1 or 2 wherein one of the contacting electrodes, namely the one connected with the cathode in placed inside said igniter. 6. The switch of claim 1 wherein it further comprises a screen, disposed in the cathode cavity between the cathode base and the trigger electrode, electrically connected to the cathode and excluding presence of direct visibility of the igniter from an anode part through the holes in the cathode base. 7. The switch of claim 1 wherein said igniter is made in the form of semiconductor compositions by means of ceramic technology with porosity not more than 40% of powders of one or some semiconductor and dielectric materials. 8. The switch of claim 1 wherein said contact electrodes are connected to the trigger circuit via active or inductive resistive elements. 9. The switch of claim 1 wherein as a trigger electrode one of contact electrodes is used.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>The basic elements of the controllable switching device are an electrode system, comprising a working discharge gap, high-voltage insulators and a trigger assembly. The trigger assembly is the most critical element of the device and it basically affects the service time, reliability and timing characteristics of the switch. Triggering of the switch can be accomplished by various means, including triggering from hot cathode and by laser shot, however prevailing methods are the triggering with a discharge over a dielectric surface, a discharge on a semiconductor element and a triggering mechanism based on an auxiliary glow discharge. When operated the switch is required to have extremely fast rise of current in an anode circuit with low and stable time delay when triggering pulse with minimum energy is applied to the a trigger assembly, as well as a sufficiently broad range of operating gas pressure in the switch, ensuring long-term operation of the switch under conditions of gas absorption in the discharge and change of electrodes temperature. The parameters significantly depend on triggering mechanism and configuration of trigger assembly—starting electrode. For the switch to operate normally it is required that the trigger part provides stable and low (less than 1 μs) delay time and, secondly, the operational life is remarkably longer than the service life of the basic electrodes of the device. One such switch—a controllable gas-discharge device (pseudospark switch), taught by application EUP N 0433480, cl. H01T 2/02, pub. 26.06.91 as well as US patent “Gas-electronic switch (pseudospark switch)” U.S. Pat. No. 5,091,819, Feb. 25, 1992, issued to J. Christiansen et al., discloses a thyratron, comprising an anode and a cathode with central holes, connecting cavities in the electrodes with main gap and trigger electrode. The trigger electrode with adjacent cathode serves as a unit triggering main discharge between electrodes of the switch. Triggering of the main gap is exercised by plasma injection from the trigger electrode under firing potential through the holes in the cathode. The known design suffers from a limited range of working gas pressure, has complicated triggering circuit configuration and low dielectric strength, which is conditioned by a presence of charged particles close to the cathode hole, generated in an auxiliary discharge, as well as high temporal instabilities (pulse edge instability, time jitter), high pulse delay time. The design is not effective for switching of energy exceeding 500 J at operating frequencies less than 100-200 Hz. Another special geometry of pseudospark switch trigger part was investigated by M. Iberler, R. Bischoff, K. Frank, I. Petzenhauser, A. Rainer, J. Urban, “Fundamental Investigation in Two Flashover-Based Trigger Methods for Low-Pressure Gas Discharge Switches”, IEEE Trans. Plasma Sci., vol. 32, no. 1, p. 208-213, 2004. The geometry has a dielectric (∈=2400) disc of 15 mm in diameter and thickness of 0.8 mm. The disc has a one-side metallization to provide reliable contact with metal substrate, whereas from another side it has pectinated contacts with a hollow electrode. In the beginning of the switch operation a dielectric igniter gives high density of emitting charge, low delay time. However under real conditions due to the fact that in this device the effect of solid dielectric surface breakdown is usually used, with time electrodes materials are sputtered over the dielectric surface, which leads to reducing of emitting charge, whereas timing characteristics of the switch become very unstable and service life is limited by damage of the ignition unit. In regimes with low operating frequency and high switching charge per shot it is the most advantageous to use semiconductor material in the igniter unit. Having relatively low specific resistance, this material is relatively more stable in terms of the aforesaid characteristics in case of conducting films evaporation in operating switch. Also in this device at the initial stage of discharge development a discharge current passes through the bulk of the igniter, that is why surface properties a lesser degree influence its characteristics within service life. The initiating of breakdown between electrodes contacting the semiconductor does not require high field strength, as it does in case of dielectric, which promotes longer operating capacity of the igniter even in case of substantial electrode erosion. The close analogy to the presented invention is 1807798, H01 J17/44, Oct. 1, 1990. N o 26 Sep. 20, 1997) {Controlled gas-discharge device, Bochkov V. D., Zaidman S. Sh. and Vosmerick Yu. M., Patent Russian Federation No. 1807798, H01 J17/44, Oct. 1, 1990, published in Bulletin of Inventions N o 26 Sep. 20, 1997}, comprising an anode and a hollow cathode with plate, facing the anode and having holes, as well as a hollow trigger electrode with a semiconductor igniter, placed in the cathode cavity. Further in the trigger assembly on the semiconductor igniter a contact element is placed, having a plurality of pins, mechanically connected with the igniter surface and galvanically coupled with the trigger electrode. In the described switch with low buffer gas pressure an ignition device based on semiconductor material with a contact element, connected with a trigger electrode, is used. The contact element in gas-discharge device represents a loop made of a refractory metal wire, wrapped by a copper wire. The wraps of the wire comprise a ribbed surface, comprising a plurality of pins, providing a multidrop contact network. The above construction have had one or more disadvantages, including the possibility to have only one contact element with a plurality of pins, which reduces life and demands strict compliance of trigger voltage polarity. Another drawback is an insufficient stability of timing parameters as well as relatively high pulse currents required for the switch triggering since even small contact area in case of linear V/A characteristic of the igniter gives too low transient resistance. The need to increase triggering power leads to a growth of power losses on the igniter, reduction of operating temperature range, degradation of frequency and service life of the switch.
|
FIELD OF THE INVENTION The present invention relates to electronics, namely to controllable powerful gas-discharge devices, and more particularly to thyratrons with non-heated cathode or “pseudospark switches”, intended for fast switching in high-current high-voltage circuits of various pulse apparatuses. BACKGROUND OF THE INVENTION The basic elements of the controllable switching device are an electrode system, comprising a working discharge gap, high-voltage insulators and a trigger assembly. The trigger assembly is the most critical element of the device and it basically affects the service time, reliability and timing characteristics of the switch. Triggering of the switch can be accomplished by various means, including triggering from hot cathode and by laser shot, however prevailing methods are the triggering with a discharge over a dielectric surface, a discharge on a semiconductor element and a triggering mechanism based on an auxiliary glow discharge. When operated the switch is required to have extremely fast rise of current in an anode circuit with low and stable time delay when triggering pulse with minimum energy is applied to the a trigger assembly, as well as a sufficiently broad range of operating gas pressure in the switch, ensuring long-term operation of the switch under conditions of gas absorption in the discharge and change of electrodes temperature. The parameters significantly depend on triggering mechanism and configuration of trigger assembly—starting electrode. For the switch to operate normally it is required that the trigger part provides stable and low (less than 1 μs) delay time and, secondly, the operational life is remarkably longer than the service life of the basic electrodes of the device. One such switch—a controllable gas-discharge device (pseudospark switch), taught by application EUP N 0433480, cl. H01T 2/02, pub. 26.06.91 as well as US patent “Gas-electronic switch (pseudospark switch)” U.S. Pat. No. 5,091,819, Feb. 25, 1992, issued to J. Christiansen et al., discloses a thyratron, comprising an anode and a cathode with central holes, connecting cavities in the electrodes with main gap and trigger electrode. The trigger electrode with adjacent cathode serves as a unit triggering main discharge between electrodes of the switch. Triggering of the main gap is exercised by plasma injection from the trigger electrode under firing potential through the holes in the cathode. The known design suffers from a limited range of working gas pressure, has complicated triggering circuit configuration and low dielectric strength, which is conditioned by a presence of charged particles close to the cathode hole, generated in an auxiliary discharge, as well as high temporal instabilities (pulse edge instability, time jitter), high pulse delay time. The design is not effective for switching of energy exceeding 500 J at operating frequencies less than 100-200 Hz. Another special geometry of pseudospark switch trigger part was investigated by M. Iberler, R. Bischoff, K. Frank, I. Petzenhauser, A. Rainer, J. Urban, “Fundamental Investigation in Two Flashover-Based Trigger Methods for Low-Pressure Gas Discharge Switches”, IEEE Trans. Plasma Sci., vol. 32, no. 1, p. 208-213, 2004. The geometry has a dielectric (∈=2400) disc of 15 mm in diameter and thickness of 0.8 mm. The disc has a one-side metallization to provide reliable contact with metal substrate, whereas from another side it has pectinated contacts with a hollow electrode. In the beginning of the switch operation a dielectric igniter gives high density of emitting charge, low delay time. However under real conditions due to the fact that in this device the effect of solid dielectric surface breakdown is usually used, with time electrodes materials are sputtered over the dielectric surface, which leads to reducing of emitting charge, whereas timing characteristics of the switch become very unstable and service life is limited by damage of the ignition unit. In regimes with low operating frequency and high switching charge per shot it is the most advantageous to use semiconductor material in the igniter unit. Having relatively low specific resistance, this material is relatively more stable in terms of the aforesaid characteristics in case of conducting films evaporation in operating switch. Also in this device at the initial stage of discharge development a discharge current passes through the bulk of the igniter, that is why surface properties a lesser degree influence its characteristics within service life. The initiating of breakdown between electrodes contacting the semiconductor does not require high field strength, as it does in case of dielectric, which promotes longer operating capacity of the igniter even in case of substantial electrode erosion. The close analogy to the presented invention is 1807798, H01 J17/44, Oct. 1, 1990. No26 Sep. 20, 1997) {Controlled gas-discharge device, Bochkov V. D., Zaidman S. Sh. and Vosmerick Yu. M., Patent Russian Federation No. 1807798, H01 J17/44, Oct. 1, 1990, published in Bulletin of Inventions No26 Sep. 20, 1997}, comprising an anode and a hollow cathode with plate, facing the anode and having holes, as well as a hollow trigger electrode with a semiconductor igniter, placed in the cathode cavity. Further in the trigger assembly on the semiconductor igniter a contact element is placed, having a plurality of pins, mechanically connected with the igniter surface and galvanically coupled with the trigger electrode. In the described switch with low buffer gas pressure an ignition device based on semiconductor material with a contact element, connected with a trigger electrode, is used. The contact element in gas-discharge device represents a loop made of a refractory metal wire, wrapped by a copper wire. The wraps of the wire comprise a ribbed surface, comprising a plurality of pins, providing a multidrop contact network. The above construction have had one or more disadvantages, including the possibility to have only one contact element with a plurality of pins, which reduces life and demands strict compliance of trigger voltage polarity. Another drawback is an insufficient stability of timing parameters as well as relatively high pulse currents required for the switch triggering since even small contact area in case of linear V/A characteristic of the igniter gives too low transient resistance. The need to increase triggering power leads to a growth of power losses on the igniter, reduction of operating temperature range, degradation of frequency and service life of the switch. DETAILED DESCRIPTION The aim of the present invention is to create a gas-discharge device with a non-heated cathode, having high hold-off voltage and longevity, reduced trigger energy and low timing uncertainty (delay) of switched current pulses in the whole range of operating voltages, as well as increased operating frequency and high temperature operating range. The present invention must have simple geometry, suitable for repetition work. This aim can be achieved utilizing a triggered gas-discharge device with non-heated cathode, comprising an anode, a hollow cathode, which is separated therefrom by a main discharge gap and whose base is oriented thereto, wherein said base is provided with openings embodied therein for coupling the main discharge gap to a trigger electrode which is arranged in the cathode cavity and is provided with an igniter made of a polycrystal semiconductor material based on a semiconductor whose energy gap is larger than 1.5 eV, the device comprises at least two contacting electrodes, connected to the igniter, wherein at least one electrode is connected to the trigger electrode, whereas the other is insulated therefrom and connected to the cathode, the maximum width of the contacting electrode in the cross-section thereof across a point where it is brought into contact with the igniter is equal to or less than 100 times the average pitch of roughness value on the igniter surface. Another distinction is that the igniter is made of polycrystalline material based on a semiconductor with non-linear current-voltage curve, having threshold voltage not greater than 5 kV. It is yet another distinction that the polycrystalline material of the igniter consists of basic semiconductor material grains, having gaps among them, filled with a semiconductor or a dielectric binding material. It is the fourth distinction that the distance between the contacting electrodes is 1-5 mm, points of contact with igniter are located on the upper side of the igniter, offering close vision of them in the direction of cathode base, whereas to avoid breakdowns in other directions the igniter is placed into a focusing screen. It is the fifth distinction that one of the contacting electrodes (CE), namely, the one, connected to the cathode, is disposed in the bulk of the igniter. It is the sixth distinction that there is a screen, electrically connected to the cathode and eliminating close visibility of the igniter from the anode side through the holes in the cathode base, and the screen is placed into the cathode cavity between cathode base and trigger electrode. It is the seventh distinction that the igniter represents semiconductor compositions made according to ceramic production methods of one or several semiconductor and dielectric powders and having porosity not exceeding 40%. It is the eighth distinction that the contacting electrodes are connected to the triggering circuit through active and inductive resistive elements. It is the ninth distinction to use one of the contacting electrodes as a trigger electrode. PREFERRED EMBODIMENTS OF THE INVENTION The following embodiments of the invention are represented in enclosed drawings. FIG. 1 is a general view of the controllable gas-discharge device. FIG. 2 is a cross-sectional view of trigger geometry of the device. FIG. 3 is a view showing the directions of cathode material evaporation, metallazing the trigger assembly. FIG. 4 shows a place of contact of the igniter with the contacting electrode. FIG. 5 is an enlarged view of the trigger geometry with internal contacting electrode. FIG. 6 is an enlarged view of the trigger geometry with conic contacting electrode. The controllable gas-discharge device comprises a housing, made of ceramic high-voltage insulators 1 and containing electrode system—a hollow cathode 2 and an anode 3, separated by main discharge gap with a screen 4, constructed to reduce metallization of insulators 1 by electrode material. Main discharge gap communicates with cathode cavity 5 via holes 7 in the cathode base facing the anode and injection space 6. In the cathode cavity there is a hollow trigger electrode 9 containing an igniter 10. The trigger electrode 9, the igniter 10, the contacting electrodes 11 and 12 and the focusing screen 13 comprise a trigger geometry. As a trigger electrode one of contacting electrodes can be utilized, however in this case the switch timing characteristics, namely, jitter and delay time can be substantially deteriorated. In order to protect the igniter from metallization by electrode materials evaporation from main discharge gap, between cathode base 2 and trigger assembly a special screen 8, blocking off a stream of evaporated metal (FIG. 3) from cathode holes 7 in the direction of electrodes 11, 12 contact points, is placed. Pins 14 and 15 of the contacting electrodes 11 and 12 as well as trigger electrode terminal 16, connected to the focusing screen 13, are connected to external control circuit. The contacting electrode may have several embodiments. FIGS. 1 and 2 show a contact electrodes geometry in the form of coupled wire holders, providing strong-fast location of the igniter. FIG. 6 shows a trigger geometry with conic contacting electrode 12 with contact part performed as periodic toothed system 21, comprising a system of contacts with disc igniter 10 surface. Similar toothed system is utilized on a contacting electrode 11. Both contacting electrodes 11 and 12 are fastened via ceramic washer 17 and 22 by a screw-nut 23 to the igniter via pin 24 and spring 18. With purpose to reduce overall dimension of the trigger assembly the electrode 11 can have simplified geometry in the form of flat washer, clasped via ceramic 17 to the side of the igniter opposing to the electrode 12, and between the contact electrode and the igniter a graphite layer just like in case of FIG. 5 can be used. The distance between the contacting electrodes 11 and 12 is L=1-5 mm (FIG. 2). The igniter 10 leans on ceramic insulator 17 via flat springs 18. In order to provide stable timing characteristics of the device it is necessary to place a point of contact with electrodes 11, 12 on an upper portion of the igniter, close to injection space as shown in FIG. 2 (point K) in the vicinity of base portion of the cathode (between beams of the “vapors” in FIG. 3). The igniter 10 is made of polycrystal material on base of a semiconductor whose energy gap is larger than 1.5 eV. This value of band-gap is characteristic for high-temperature semiconductors like silicon carbide, boron nitride etc. At the expense of polycrystallic structure the igniter has rather rough surface with plurality of spikes c and e (FIG. 4). The spikes have relatively small average step and deviation of profile by height yi from a base line (B.L.). The value D/Sm is a criteria of contact transparency, where D—a cross-sectional width of contact electrode in the point of contact with the igniter, i.e. the dimension parallel to base line (B.L.) of the igniter. The contact electrode is clasped to the igniter surface and has electrical contact with it via spikes c and e, comprising a certain amount of contact points with contacting electrodes 11 and 12 each one with its own transient resistance. In principle discharge triggering can be accomplished on smooth surface as well. However the existence of spikes on the igniter surface and the contacting electrodes improves the device characteristics. Depending on the igniter material characteristic voltage the electrodes can be located at the distance 1-5 mm from each other. At that the prescribed width of contacting electrode must not exceed the average pitch of roughness value on the igniter surface more than in 100 times (D/Sm<100). Higher limiting values are allowed for round or knife-type contacting electrodes, lower—for square electrodes. The igniter may have non-linear characteristic. Non-linear voltage-current characteristic (VCC) of the igniter can be achieved provided that the igniter is fabricated of a semiconductor compounds crystals conglomerate, e.g. silicon carbide (boron carbides, boron and aluminum nitrides, zinc oxide and other high-temperature semiconductors can be utilized). However the aforesaid conglomerates, even being baked at very high temperatures, will be unstable and extremely sensitive to jolting, impacts and can easily change their characteristics. That is why the grains of semiconductor compositions must be bound by a sticker. In this case the igniter material is fabricated in the form of semiconductor compositions utilizing ceramic technology methods, thereby a powder of basic semiconductor material with interstice dilled with a semiconductor or a dielectric compound (e.g. sodium silicate). At that in order to simplify triggering circuits the materials must have threshold (characteristic) voltage not greater than 5 kV. Trigger geometry can comprise internal contacting electrode 11 (FIG. 5), located at the distance L from the point of contact K CE 12 with the igniter. In this case the distance L is counted off not by the surface as in FIG. 2, but by the igniter volume. The distinction is also that between the electrode 12 and the igniter internal surface a graphite layer 20 can be used to reduce transient resistance of internal contact. It is made to provide sparking on the igniter external surface only. Introduction of the internal contacting electrode allows to increase in principle a quantity of contact points on the surface (e.g. bridging external contact electrodes 12), distribute them along the full length of the igniter, thereby increasing a service time of trigger assembly. It is worth noting that further increase of the contacting electrodes quantity (over 4-5) does not improve effectiveness of the trigger geometry as for construction in FIG. 1 this will lead to reinforcement of a contact surfaces screening, whereas for construction in FIG. 5 this will lead to increase in transfer capacitance, bridging trigger circuit. The switch is filled with hydrogen or deuterium at the pressure of 0.1-0.6 millimeters of mercury to provide high hold-off voltage on the left hand brand branch of the Paschen curve. During use of the device one of the contacting electrodes is connected to the cathode (either directly or, in order to reduce discharge development time, via resistor 10-100 Ohm or inductivity not larger than 1 μH) while another—with trigger circuit. When applying to the electrode a negative (in respect to the cathode potential) voltage pulse exceeding a threshold value (characteristic voltage accepted for description of varistor-type semiconductor material), the igniter resistance declines sharply and a major part of energy is evolved in one of the contact points as a sparkle. If trigger energy and charged particles emission density are high enough, the sparkle plasma initiates a development of a discharge, overlapping gas distance between electrodes 11 and 12 (having negative potential) that afterwards due to emerging potential difference is spread to the base part of the cathode 2 (FIG. 1). A resistor in a circuit between the cathode and the contacting electrode assures acceleration of this process owing to the fact that due to the passing the trigger current a potential of contact electrode sharply drops below cathode value leading to acceleration of discharge transfer to the cathode (into an injection area). Appropriate tests show that such a configuration assures current rise of 120 kA within 50 ns, i.e. current rise rates exceeding 2·1012 A/s. A trigger electrode 9 (FIG. 2) having upper screen 13 with a hole promotes plasma beam focusing in the direction of injection area 6 (FIG. 1) and stabilizes the beam position in respect to the switch axis, assuring low time jitter and delay time. Electrons from plasma beam are injected through cathode holes 7 into a gap between cathode 2 and anode 3 of the device thus initiating a main discharge. The condition of maximum transparency of electrode contact points with an igniter must be fulfilled for electrical field of cathode base. As shown in FIG. 4 when a contact electrode 12 is connected with the igniter 10 in medium part of the electrode (lug c) at a level D/Sm>3 (Sm is the average pitch of roughness value on the igniter surface) the output of charged particles from a spark plasma into a trigger electrode cavity and into an injection space is hampered in comparison with a place of contact on the edge of electrode. Under natural conditions the plasma injection depends on energy dissipated during micro-explosions (sparks). At that due to a sharp rise of the spark internal pressure the plasma can rapidly jump out off a narrow slit between the contacting electrode and the igniter, which somehow reduces shielding effect. This allows to sufficiently increase D/Sm, which is important for simplification of the trigger part assembling process. It is worth noting that the specified levels of D/Sm are selected from experimental data, higher values relate to the case of higher quality of surface processing (low roughness), e.g. for polished up to Ra=1.6 μm (profile yi normal deviation according to RF standard ΓOCT25142-82). However the use of materials with low roughness (at Sm less than 1.6 μm obtained by buffing) is inexpedient on one part due to economical reasons, on another part due to necessity to reduce the dimension D of the contacting electrode in order to provide contact transparency (D/Sm<100), which leads to reduction of the electrode mass and quick failure of the device due to erosion within service time. For values of D/Sm over 100 at the beginning of service time the operation of the device can be rather stable (without misfire of the main discharge), but as the contacting electrodes and the igniter are being used, the places of contact go deep down into the electrodes center. In this case right after a spark appears that is for formally good function of a trigger, due to problematic output of plasma from the contact place into a trigger electrode vicinity, reliability can be sharply reduced due to appearance of misfire in the anode part of the device. The optimal ratio for round contacting electrodes dimensions (D/H=1 over the range of D from 1 to 2 mm) and igniter surface roughness is D/Sm=10-40. The distance between the contacting electrodes 11 and 12 is a determinative for ensuring a reliable triggering. The best choice of 1-5 mm can be explained by the following factors. The effectiveness of trigger part is maximum provided that the major portion of trigger pulse energy is dissipated in contact points, ideally in one point. If the distance exceeds 5 mm the power losses in the bulk of the semiconductor igniter grow, which requires increase of power of trigger pulse generator thus reducing effectiveness of the device. This is particularly important for the igniters with higher resistances, in particular with non-linear voltage-current characteristic. On the other hand due to the fact that spring-loaded construction is not strictly rigid but has some freeness, the distances less than 1 mm under operational conditions of the device (thermal change, vibrations, contact electrode erosion) are hard to provide due to technological reasons and in the course of operation there can be short-circuits in the contact electrodes. In the process of operation the igniter 10 and the electrodes 11 and 12 material (FIG. 3) evaporates gradually, however due to elastic properties of the spring 18 their contact remains good for a long time. Since the electrode with a negative potential is eroded more than others during operation, the service time of the device can be prolonged by changing polarity of starting electrodes. The discharge initiation in the anode part of the switch can be executed in two regimes: by a spark, emerging in a contact point of the igniter 10 with the electrodes 11 or 12 and by an arc, emerging between the electrode 11 and 12 and then between one of the electrodes 11 (12) having negative polarity and cathode base 2 (FIG. 1). The first mean requires less energy but has higher instability (jitter greater than 1 μs) of delay time from pulse to pulse and within service time. Whereas the arc discharge offers more stable parameters of the device within service time, but trigger voltage must be not less than 2 kV and current not less than 10 A at trigger voltage rise rate exceeding 5 kV/μs. Unlike typical configurations the use of high-resistance semiconductor igniter having non-linear voltage-current characteristic significantly simplifies geometry by avoiding an artificial multidrop contact and using smooth contact electrodes 11 and 12. The geometry offers at least not worse than existing level of switching characteristics at higher frequency capability and significantly higher operational temperature. However due to the presence of additional element, namely the development of the contacting electrodes surface as a periodic structure with macrospikes (see for example FIG. 6) the discharge initiation energy can be reduced whereas the resource of electrode material is growing simultaneously with increase of contact transparency (screening reduction by electrodes 11 and 12). In the semiconductor igniter with linear voltage-current characteristic (VCC) the current is distributed all over the volume that is why to provide a sufficient power of the spark, initiating the process of discharge firing, the igniter must have relatively low resistance (from some tens Ohms up to some kOhm). Under normal thermal conditions the element requires current value exceeding 80 A, whereas at increased operational temperatures (more than 150° C.) due to significant reduction of the igniter resistance the stable operation of the device is provided only with trigger currents exceeding 150 A. That is why for such conditions the igniter with non-linear VCC is more effective. The application of the igniter made of a polycrystal material based on a semiconductor whose energy gap is larger than 1.5 eV and specific resistance is larger than 10 kOhm/cm, especially a material with non-linear VCC, ensures improvement of several important parameters of the device: sharp current rise occurs only in one or at the most in some points of contact of electrodes with the igniter surface as after that the other contact points appear to be under potential which is less than characteristic value, which, preserving high energy liberation density in the contact point, allows to substantially reduce a driver power; non-linear (varistor) voltage-current characteristic ensures sharpening of trigger current pulse edge, more effective use of energy and reduction of delay time and time jitter; wide-gap semiconductor due to less dependence on temperature ensures a capacity for work at significantly higher temperatures (up to 500 ∈C and even more) and at higher pulse repetition rates; the igniter made of basic material with filler features higher mechanical strength and porosity less than 40%, thus promoting a process of the device pump-down. The igniter with non-linear VCC in comparison with a linear VCC device is capable of operating at significantly higher initial resistance, that at voltage less than characteristic usually comprises from some kOhm up to some tens MOhm. The device with the described igniter was tested in the following regime—peak anode voltage from 1 to 50 kV, peak current up to 200 kA, charge transfer up to tens Coulomb. At that the delay time was 0.1-0.3 μs, time jitter was less than 5 ns, igniter service time was about 50-100 millions of shots. The firing energy for the present construction is reduced in several times in comparison with the igniter with linear VCC, at that a trigger pulse voltage can be reduced up to 0.5-1 kV, peak current value up to 10-20A. The present igniter operates effectively in a wide range of temperature (from −60 to +500° C.), ensuring stable temporal parameters.
|
H
|
H01
|
H01J
|
17
|
04
|
||||
11808833
|
US20070236532A1-20071011
|
Liquid ejecting apparatus
|
ACCEPTED
|
20070926
|
20071011
|
[]
|
B41J2165
|
["B41J2165"]
|
7641305
|
20070613
|
20100105
|
347
|
029000
|
71912.0
|
HSIEH
|
SHIH WEN
|
[{"inventor_name_last": "Mano", "inventor_name_first": "Takashi", "inventor_city": "Nagano-ken", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Kuwada", "inventor_name_first": "Shozo", "inventor_city": "Nagano-ken", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Takahashi", "inventor_name_first": "Nobuhito", "inventor_city": "Nagano-ken", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Hayakawa", "inventor_name_first": "Hitoshi", "inventor_city": "Nagano-ken", "inventor_state": "", "inventor_country": "JP"}]
|
A printer includes a cleaning mechanism that reliably performs an operation of cleaning a liquid ejecting head with a small amount of driving energy. The cleaning mechanism includes a cap manufactured by coinjection molding of a core part and an elastic part. The cap includes a bottom surface, an outer wall, and a partition wall dividing a cap inner space surrounded by the outer wall into two. A ratio of the elastic part in the partition wall is higher than that in the outer wall. With this structure, the partition wall is more elastically deformable than the outer wall. When the cap comes into contact with a nozzle surface of a recording head and covers nozzle rows, the outer wall comes into contact with the nozzle surface with a larger stress compared with the partition wall, and seals chambers where the nozzle rows on the nozzle surface are exposed.
|
1. A liquid ejecting apparatus for ejecting a liquid toward a target, the liquid ejecting apparatus comprising: a liquid ejecting head including a nozzle surface that has a plurality of nozzles for ejecting the liquid; a cap including an outer wall that defines an opening, the opening being closed by the nozzle surface, wherein the outer wall comes into contact with the nozzle surface and the plurality of nozzles are covered by the cap when the nozzle surface closes the opening; an aspiration mechanism, connected to the cap, for aspirating fluid in an inner space of the cap and draining the fluid from the inner space of the cap, wherein the cap includes a partition wall that comes into contact with the nozzle surface and defines a plurality of chambers together with the nozzle surface and the outer wall when the nozzle surface closes the opening, and wherein the cap includes a first contact part that is arranged in the outer wall and that has a first thickness and a second contact part that is arranged in the partition wall and that has a second thickness, the second thickness being less than the first thickness. 2. A printer apparatus for ejecting a liquid toward a print surface, the printer apparatus comprising: a linearly movable printer head that stores the liquid, wherein the printer head includes a nozzle surface that has a plurality of nozzles for ejecting droplets of the liquid toward the print surface; and a cleaning mechanism for cleaning the plurality of nozzles when the printer head is placed at a home position, wherein the cleaning mechanism includes: a cap for covering the plurality of nozzles when the printer head is at the home position; and an aspiration mechanism, connected to the cap, for depressurizing an inner space of the cap and draining the fluid from the inner space of the cap when the cap covers the plurality of nozzles, wherein the cap includes an outer wall and an inner wall that define a plurality of chambers in the cap, wherein the outer wall has a first contact part that comes into contact with the nozzle surface, the inner wall has a second contact part that comes into contact with the nozzle surface, and the second contact part is more easily deformable than the first contact part. 3. The printer apparatus according to claim 2, wherein the second contact part is thinner than the first contact part.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>The present invention relates to a liquid ejecting apparatus. A printer that prints by ejecting ink droplets from a recording head toward a recording medium is known as a liquid ejecting apparatus for ejecting a liquid onto a target. In conventional printers, solvents of ink may vaporize within a recording head and the vaporized solvents may diffuse from nozzles of the recording head. If this happens, viscosity of the ink in the recording head increases. The increased ink viscosity may clog the nozzles, or may cause dust to adhere to the nozzles. Also, air bubbles may enter from the nozzles into the recording head when the ink cartridge is replaced. Such entry of air bubbles and clogging of the nozzles may cause printing failures. To prevent printing failures, conventional printers perform a cleaning operation for aspirating ink out of nozzles of the recording head. By aspirating ink out of the nozzles, such nozzle problems as clogging, adhesion of dust, and entry of air bubbles are prevented. The following describes the cleaning operation in detail. A cleaning mechanism arranged in a printer typically performs the cleaning operation. The cleaning mechanism includes a cap for covering nozzles of a recording head, an ink drain path that is connected to the cap, and a depressurizing pump arranged midway on the ink drain path. The cap is placed to cover the nozzles of the recording head, and the depressurizing pump is driven, so that the inner pressure of the cap is decreased. This causes ink to be aspirated out of the nozzles of the recording head. The aspirated ink is drained via the ink drain path. With this operation, clogging of the nozzles is prevented. A conventional printer for color printing uses inks of plural colors, e.g., Cyan, Magenta, Yellow, and Black. The printer using inks of plural colors has, on its recording head, nozzle rows whose number corresponds to the number of the colors. Such a printer may perform the cleaning operation by covering all the nozzle rows on the recording head with a cap, and aspirating ink out of all the nozzle rows at the same time. With this cleaning operation, however, ink is aspirated even from nozzles that are not clogged. As a result, excess ink is consumed. To reduce such wasting of ink, Japanese Laid-Open Patent Publication No. 2000-225715 proposes a cleaning mechanism that selectively aspirates ink only from nozzle rows that require cleaning. In detail, a cap of this cleaning mechanism has a plurality of chambers. A plurality of ink drain paths in one-to-one correspondence with the chambers are arranged between the chambers and a depressurizing pump. Each ink drain path has a valve. During the cleaning operation, a valve on each ink drain path is adjusted to open and close according to the clog state of the corresponding nozzle row. Among the plurality of chambers of the cap, only a chamber connected to an ink drain path whose valve is open is depressurized. Ink is aspirated out of the nozzle row corresponding to the depressurized chamber. In this way, this cleaning mechanism aspirates ink only from nozzle rows that require removal of clogging, so that wasting of ink is reduced. To improve color reproduction and gloss of a printed image, a printer that ejects reactive ink from its recording head in addition to normal color ink is conventionally known. The reactive ink includes clear (colorless) ink. The reactive ink coagulates with color ink on a recording medium, to improve color reproduction and gloss of a printed image. When the printer that uses reactive ink performs the cleaning operation, color ink and reactive ink may react and coagulate within a cap. This may degrade the function of the cleaning mechanism. To prevent such a coagulating reaction of color ink and reactive ink within the cap and prevent degradation of the cleaning mechanism function, this printer may also employ the above-described cap, which has a plurality of chambers. The above-described cap has its case unit being divided into a plurality of chambers by a partition wall. During the cleaning operation, an upper edge of the case unit and an upper edge of the partition wall simultaneously come into contact with the nozzle surface of the recording head. When this cap is brought into contact with the nozzle surface, however, the upper edge of the case unit and/or the upper edge of the partition wall may be stress-deformed under a load, which is caused by a spring pressing the cap. For example, the upper edge of the partition wall may come in close contact with the nozzle surface, whereas the upper edge of the case unit may not come in close contact with the nozzle surface. In this way, the cap may often unevenly come into contact with the nozzle surface. Such uneven contact between the cap and the nozzle surface lowers sealing performance of the cap, and degrades the function of the cleaning mechanism. To solve this problem, one technique is known to form a part of the cap that comes into contact with the nozzle surface using an elastic material, such as an elastomer. This technique ensures close contact and tight sealing between the cap and the nozzle surface by bringing the cap into contact with the nozzle surface with a relatively strong force and excessively deforming the elastomer. However, a relatively large amount of energy is required to bring the cap into contact with the nozzle surface with a relatively strong force. This may require a larger motor to be used for the cleaning operation, and may increase the cost of the printer. This may also cause wear of a driving unit for operating the cap, and may reduce durability of the printer.
|
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which: FIG. 1 is a perspective view of a printer according to a first embodiment of the present invention; FIG. 2 is a bottom view of a carriage of the printer of FIG. 1 ; FIG. 3 is a sectional view of essential parts of the printer of FIG. 1 ; FIG. 4 is a perspective view of a cap of the printer of FIG. 1 ; FIG. 5 is a plan view of the cap of FIG. 4 ; FIG. 6 is a sectional view of the cap of FIG. 4 ; FIG. 7 is a partial sectional view of the cap of FIG. 4 ; FIG. 8 is a partial sectional view of the cap of FIG. 4 ; FIG. 9 is a sectional view of essential parts of the printer according to a second embodiment of the present invention; FIG. 10 is a perspective view of a cap of the printer of FIG. 9 ; FIG. 11 is a plan view of the cap of FIG. 10 ; FIG. 12 is a sectional view of the cap of FIG. 10 ; FIG. 13 is a partial sectional view of the cap of FIG. 10 ; FIG. 14 is a sectional view of the cap of FIG. 10 ; FIGS. 15 and 16 are partial sectional views of a cap according to a first modification of the present invention; FIG. 17 is a perspective view of a cap according to a second modification of the present invention; and FIG. 18 is a perspective view of a cap according to a third modification of the present invention. detailed-description description="Detailed Description" end="lead"?
|
CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 10/953,108 which is based upon and claims the benefit of priority from prior Japanese Patent Application Nos. 2003-342862, filed on Oct. 1, 2003, and 2004-239842, filed on Aug. 19, 2004, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION The present invention relates to a liquid ejecting apparatus. A printer that prints by ejecting ink droplets from a recording head toward a recording medium is known as a liquid ejecting apparatus for ejecting a liquid onto a target. In conventional printers, solvents of ink may vaporize within a recording head and the vaporized solvents may diffuse from nozzles of the recording head. If this happens, viscosity of the ink in the recording head increases. The increased ink viscosity may clog the nozzles, or may cause dust to adhere to the nozzles. Also, air bubbles may enter from the nozzles into the recording head when the ink cartridge is replaced. Such entry of air bubbles and clogging of the nozzles may cause printing failures. To prevent printing failures, conventional printers perform a cleaning operation for aspirating ink out of nozzles of the recording head. By aspirating ink out of the nozzles, such nozzle problems as clogging, adhesion of dust, and entry of air bubbles are prevented. The following describes the cleaning operation in detail. A cleaning mechanism arranged in a printer typically performs the cleaning operation. The cleaning mechanism includes a cap for covering nozzles of a recording head, an ink drain path that is connected to the cap, and a depressurizing pump arranged midway on the ink drain path. The cap is placed to cover the nozzles of the recording head, and the depressurizing pump is driven, so that the inner pressure of the cap is decreased. This causes ink to be aspirated out of the nozzles of the recording head. The aspirated ink is drained via the ink drain path. With this operation, clogging of the nozzles is prevented. A conventional printer for color printing uses inks of plural colors, e.g., Cyan, Magenta, Yellow, and Black. The printer using inks of plural colors has, on its recording head, nozzle rows whose number corresponds to the number of the colors. Such a printer may perform the cleaning operation by covering all the nozzle rows on the recording head with a cap, and aspirating ink out of all the nozzle rows at the same time. With this cleaning operation, however, ink is aspirated even from nozzles that are not clogged. As a result, excess ink is consumed. To reduce such wasting of ink, Japanese Laid-Open Patent Publication No. 2000-225715 proposes a cleaning mechanism that selectively aspirates ink only from nozzle rows that require cleaning. In detail, a cap of this cleaning mechanism has a plurality of chambers. A plurality of ink drain paths in one-to-one correspondence with the chambers are arranged between the chambers and a depressurizing pump. Each ink drain path has a valve. During the cleaning operation, a valve on each ink drain path is adjusted to open and close according to the clog state of the corresponding nozzle row. Among the plurality of chambers of the cap, only a chamber connected to an ink drain path whose valve is open is depressurized. Ink is aspirated out of the nozzle row corresponding to the depressurized chamber. In this way, this cleaning mechanism aspirates ink only from nozzle rows that require removal of clogging, so that wasting of ink is reduced. To improve color reproduction and gloss of a printed image, a printer that ejects reactive ink from its recording head in addition to normal color ink is conventionally known. The reactive ink includes clear (colorless) ink. The reactive ink coagulates with color ink on a recording medium, to improve color reproduction and gloss of a printed image. When the printer that uses reactive ink performs the cleaning operation, color ink and reactive ink may react and coagulate within a cap. This may degrade the function of the cleaning mechanism. To prevent such a coagulating reaction of color ink and reactive ink within the cap and prevent degradation of the cleaning mechanism function, this printer may also employ the above-described cap, which has a plurality of chambers. The above-described cap has its case unit being divided into a plurality of chambers by a partition wall. During the cleaning operation, an upper edge of the case unit and an upper edge of the partition wall simultaneously come into contact with the nozzle surface of the recording head. When this cap is brought into contact with the nozzle surface, however, the upper edge of the case unit and/or the upper edge of the partition wall may be stress-deformed under a load, which is caused by a spring pressing the cap. For example, the upper edge of the partition wall may come in close contact with the nozzle surface, whereas the upper edge of the case unit may not come in close contact with the nozzle surface. In this way, the cap may often unevenly come into contact with the nozzle surface. Such uneven contact between the cap and the nozzle surface lowers sealing performance of the cap, and degrades the function of the cleaning mechanism. To solve this problem, one technique is known to form a part of the cap that comes into contact with the nozzle surface using an elastic material, such as an elastomer. This technique ensures close contact and tight sealing between the cap and the nozzle surface by bringing the cap into contact with the nozzle surface with a relatively strong force and excessively deforming the elastomer. However, a relatively large amount of energy is required to bring the cap into contact with the nozzle surface with a relatively strong force. This may require a larger motor to be used for the cleaning operation, and may increase the cost of the printer. This may also cause wear of a driving unit for operating the cap, and may reduce durability of the printer. DISCLOSURE OF THE INVENTION One aspect of the present invention is a liquid ejecting apparatus for ejecting a liquid toward a target. The liquid ejecting apparatus includes a liquid ejecting head including a nozzle surface that has a plurality of nozzles for ejecting the liquid. A cap includes an outer wall that defines an opening, which is closed by the nozzle surface. The outer wall comes into contact with the nozzle surface and the plurality of nozzles are covered by the cap when the nozzle surface closes the opening. An aspiration mechanism connected to the cap aspirates fluid in an inner space of the cap and drains the fluid from the inner space of the cap. The cap includes a partition wall that comes into contact with the nozzle surface and defines a plurality of chambers together with the nozzle surface and the outer wall when the nozzle surface closes the opening. The outer wall is formed to receive a first stress when coming into contact with the nozzle surface, and the partition wall is formed to receive a second stress less than the first stress when coming into contact with the nozzle surface. Another aspect of the present invention is a liquid ejecting apparatus for ejecting a liquid toward a target. The liquid ejecting apparatus includes a liquid ejecting head including a nozzle surface that has a plurality of nozzles for ejecting the liquid. A cap includes an outer wall and a partition wall. The outer wall defines an opening that is closed by the nozzle surface. The partition wall divides the opening into a plurality of chambers. When the nozzle surface closes the opening, the plurality of nozzles are covered by the cap, the outer wall comes into contact with the nozzle surface, and the partition wall is spaced from the nozzle surface. An aspiration mechanism connected to the cap aspirates fluid in an inner space of the cap and drains the fluid from the inner space of the cap. Another aspect of the present invention is a printer apparatus for ejecting a liquid toward a print surface. The printer apparatus includes a linearly movable printer head that stores the liquid. The printer head includes a nozzle surface that has a plurality of nozzles for ejecting droplets of the liquid toward the print surface. A cleaning mechanism cleans the plurality of nozzles when the printer head is placed at a home position. The cleaning mechanism includes a cap for covering the plurality of nozzles when the printer head is at the home position, and an aspiration mechanism, connected to the cap, for depressurizing an inner space of the cap and draining the fluid from the inner space of the cap when the cap covers the plurality of nozzles. The cap includes an outer wall and an inner wall that define a plurality of chambers in the cap, and the outer wall relatively strongly presses the nozzle surface and the inner wall relatively weakly presses the nozzle surface when the cap covers the plurality of nozzles. Other aspects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which: FIG. 1 is a perspective view of a printer according to a first embodiment of the present invention; FIG. 2 is a bottom view of a carriage of the printer of FIG. 1; FIG. 3 is a sectional view of essential parts of the printer of FIG. 1; FIG. 4 is a perspective view of a cap of the printer of FIG. 1; FIG. 5 is a plan view of the cap of FIG. 4; FIG. 6 is a sectional view of the cap of FIG. 4; FIG. 7 is a partial sectional view of the cap of FIG. 4; FIG. 8 is a partial sectional view of the cap of FIG. 4; FIG. 9 is a sectional view of essential parts of the printer according to a second embodiment of the present invention; FIG. 10 is a perspective view of a cap of the printer of FIG. 9; FIG. 11 is a plan view of the cap of FIG. 10; FIG. 12 is a sectional view of the cap of FIG. 10; FIG. 13 is a partial sectional view of the cap of FIG. 10; FIG. 14 is a sectional view of the cap of FIG. 10; FIGS. 15 and 16 are partial sectional views of a cap according to a first modification of the present invention; FIG. 17 is a perspective view of a cap according to a second modification of the present invention; and FIG. 18 is a perspective view of a cap according to a third modification of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes a liquid ejecting apparatus according to a first embodiment of the present invention, with reference to FIGS. 1 to 8. FIG. 1 shows a printer 11 as the liquid ejecting apparatus according to the first embodiment. The printer 11 includes a frame 12, a guide member 14, a carriage 15, a recording head 20 as a liquid ejecting head, a color ink cartridge 21, a reactive ink cartridge 22, a platen 23, a waste liquid tank 25, and a cleaning mechanism 27. The frame 12 covers the entire apparatus part of the printer 11. Between both side-walls of the frame 12, the guide member 14 extends in the longitudinal direction of the frame 12. The guide member 14 is inserted through the carriage 15, and supports the carriage 15 in a slidable manner. The carriage 15 is connected to a carriage motor 29 via a timing belt 28. The carriage 15 reciprocates in a direction in which the guide member 14 extends, i.e., in a main-scanning direction X, when the carriage motor 29 is driven. The recording head 20 is mounted under the carriage 15. As shown in FIG. 2, a bottom surface of the recording head 20 is a nozzle surface 20a on which a plurality of nozzles are formed. In the first embodiment, as shown in FIG. 2, four nozzle rows 31a to 31d are formed in the left half of the nozzle surface 20a, and one nozzle row 31e is formed in the right half of the nozzle surface 20a. As shown in FIG. 1, the color ink cartridge 21 and the reactive ink cartridge 22 are arranged on the carriage 15 in parallel with each other. The color ink cartridge 21 stores color ink. The reactive ink cartridge 22 stores reactive ink. The color ink and the reactive ink are respectively supplied from the cartridges 21 and 22 to the recording head 20 when a piezoelectric element (not shown) in the recording head 20 is driven. The nozzle rows 31a to 31d eject, as ink droplets, the color ink supplied from the color ink cartridge 21. The nozzle row 31e ejects, as ink droplets, the reactive ink supplied from the reactive ink cartridge 22. As shown in FIG. 1, the platen 23 is a holder for holding a paper sheet P as a target. The platen 23 is attached to the frame 12 to be parallel with the guide member 14 and to face the recording head 20. The recording head 20 faces the paper sheet P placed on the platen 23. A paper feeding mechanism (not shown) arranged on the platen 23 feeds the paper sheet P in a sub-scanning direction Y (refer to FIG. 1). With the carriage 15 reciprocating along the guide member 14, the piezoelectric element is driven according to print data. Then, ink droplets are ejected from the recording head 20 toward the paper sheet P. In this way, printing is performed. In the first embodiment, ink droplets of the color ink are first ejected and then ink droplets of the reactive ink are ejected, so that the reactive ink droplets are adhered on the color ink droplets, which are adhered on the paper sheet P. The reactive ink and the color ink react and coagulate on the paper sheet P. This improves color reproduction and gloss of the color ink. In this way, an image with improved color reproduction and gloss is printed on the paper sheet P. As shown in FIGS. 1 and 3, the waste liquid tank 25 is formed as a case having a top opening. The arrangement position and the size of the waste liquid tank 25 are determined so that the entire bottom surface of the platen 23 is placed in the top opening of the waste liquid tank 25. As shown in FIG. 3, a plurality of waste liquid absorbing members 31 made from a porous material are placed one on top of another within the waste liquid tank 25. As shown in FIGS. 1 and 3, the cleaning mechanism 27 is placed in a non-print area (at a home position) of the printer 11. For example, the cleaning mechanism 27 is placed in a right end part of the printer 11 shown in FIG. 3. The cleaning mechanism 27 includes a cap 32, and an aspiration mechanism connected to the cap 32. The aspiration mechanism includes aspiration tubes 33 and 34 and an aspiration pump 36. The aspiration tubes 33 and 34 connect the cap 32 and the waste liquid tank 25. The aspiration pump 36 is arranged midway on the aspiration tubes 33 and 34. As shown in FIGS. 4 and 5, the cap 32 includes a rectangular bottom surface 38 and an outer wall 41. The outer wall 41 is arranged along the outer rim of the bottom surface 38. The cap 32 is formed as a case having a top opening. In the first embodiment, the bottom surface 38 is a little smaller than the nozzle surface 20a of the recording head 20 (refer to FIG. 2). The cap 32 further includes a partition wall 43 in the middle of the bottom surface 38. The partition wall 32 extends in the sub-scanning direction Y. The partition wall 43 is placed in the middle of the cap 32 as viewed in the main-scanning direction X. The partition wall 43 divides, into two, an inner space of the cap 32, which is defined by the bottom surface 38 and the outer wall 41 of the cap 32. To be specific, the bottom surface 38, the outer wall 41, and the partition wall 43 define a first case unit (partitioned chamber) 45 and a second case unit (partitioned chamber) 47 as shown in FIG. 5. The first case unit 45 and the second case unit 47 have substantially the same volume. Each of the first case unit 45 and the second case unit 47 has an opening, which is open to outside air. As shown in FIG. 6, the cap 32 has a core part 49, and an elastic part 51 as a contact part. The core part 49 is made from a resin material, such as plastic. The elastic part 51 is made from an elastic material, such as an elastomer. The core part 49 and the elastic part 51 are integrally formed, for example, by coinjection molding. The following describes the outer wall 41 and the partition wall 43 in detail. As shown in FIG. 7, the outer wall 41 includes an outer-wall resin part 41a and an outer-wall elastic part 41b. The outer-wall resin part 41a is made from a resin material, and is arranged continuous from the bottom surface 38. The outer-wall elastic part 41b is made from an elastic material, and covers an upper edge and a side surface of the outer-wall resin parts 41a. As shown in FIG. 8, the partition wall 43 includes a partition-wall resin part 43a and a partition-wall elastic part 43b. The partition-wall resin part 43a is made from a resin material, and is arranged continuous from the bottom surface 38. The partition-wall elastic part 43b is made from an elastic material, and covers an upper edge and a side surface of the partition-wall resin part 43a. As shown in FIG. 7, height H1 of the outer-wall resin part 41a, i.e., distance from the bottom surface 38 to the upper edge of the outer-wall resin part 41a, is uniform throughout the outer-wall resin part 41a. As shown in FIG. 8, height H2 of the partition-wall resin part 43a is uniform throughout the partition-wall resin part 43a. The height H2 is less than the height H1 (refer to FIG. 7). As shown in FIG. 7, the outer-wall elastic part 41b projects from the upper edge of the outer-wall resin part 41a by height hl. In other words, distance from the upper edge of the outer-wall resin part 41a to the upper edge of the outer-wall elastic part 41b is the height h1. As shown in FIG. 8, the partition-wall elastic part 43b projects from the upper edge of the partition-wall resin part 43a by height h2. In other words, distance from the upper edge of the partition-wall resin part 43a to the upper edge of the partition-wall elastic member part 43b is the height h2. The projection height h2 is greater than the projection height h1. Distance from the bottom surface 38 to the upper edge of the outer-wall elastic part 41b is equal to the distance from the bottom surface 38 to the upper edge of the partition-wall elastic part 43b. In other words, the height H1 plus the projection height h1 is equal to the height H2 plus the projection height h2. The outer wall 41 and the partition wall 43 have the same entire height from the bottom surface 38. The outer wall 41 and the partition wall 43 are different in their ratios of the core part 49 and the elastic part 51 in the height direction. The ratio of the elastic part 51 in the partition wall 43 is higher than that in the outer wall 41. With this structure, the partition wall 43 is more elastically deformable than the outer wall 41. The outer-wall elastic part 41b is tapered to its upper edge 41c. The partition-wall elastic part 43b is tapered to its upper edge 43c. Each of the upper edges 41c and 43c forms a flat planar surface parallel to the bottom surface 38. Width L1 of the upper edge 41c of the outer-wall elastic part 41b in the main-scanning direction X (refer to FIG. 6) is less than width L2 of the upper edge 43c of the partition-wall elastic part 43b in the main-scanning direction X. As shown in FIG. 5, the case unit 45 has a first drain outlet 53 formed in the bottom surface 38, and the case unit 47 has a second drain outlet 55 formed in the bottom surface 38. As shown in FIGS. 4 and 5, each of the case units 45 and 47 has, on the bottom surface 38, seven substantially cylindrical supporting members 57, which project outward. An ink absorbing sheet (not shown) is placed in each of the case units 45 and 47. In each of the case units 45 and 47, the supporting members 57 pierce through the ink absorbing sheet, to fix the ink absorbing sheet to the case unit. As shown in FIG. 3, the cap 32 is raised and lowered by a well-known raising and lowering mechanism (not shown), with its top opening oriented upward and its bottom surface 38 (refer to FIG. 4) parallel to the nozzle surface 20a. The raising and lowering mechanism is attached to the frame 12. When the carriage 15 is moved to the home position, the cap 32 is raised, and is brought into contact with the nozzle surface 20a (refer to FIG. 2) of the recording head 20 of the carriage 15. When the cap 32 and the nozzle surface 20a come into contact with each other, the nozzle rows 31a to 31d (refer to FIG. 2) are covered by the first case unit 45, and the nozzle row 31e (refer to FIG. 2) is covered by the second case unit 47. The aspiration tubes 33 and 34 are made from an elastic material, such as silicon rubber. One end of the aspiration tube 33 is connected to the first drain outlet 53 (refer to FIG. 5) of the cap 32. One end of the aspiration tube 34 is connected to the second drain outlet 55 (refer to FIG. 5) of the cap 32. The other ends of the aspiration tubes 33 and 34 are placed in the waste liquid tank 25. An inner space of the first case unit 45 of the cap 32 is in fluid communication with the waste liquid tank 25 via the aspiration tube 33. An inner space of the second case unit 47 of the cap 32 is in fluid communication with the waste liquid tank 25 via the aspiration tube 34. In this way, the first and second case units 45 and 47 are separately connected to the waste liquid tank 25. The aspiration pump 36 is arranged midway on fluid-flow paths of the aspiration tubes 33 and 34. The aspiration pump 36 aspirates various fluids flowing upstream of the aspiration tubes 33 and 34, such as air and ink. An inner space defined by the recording head 20 and the cap 32 is depressurized when the aspiration pump 36 is driven with the nozzle surface 20a (refer to FIG. 2) of the recording head 20 being sealed by the cap 32. The following describes the cleaning operation for the printer 11. In the cleaning operation, the carriage 15 is first moved to the home position (FIG. 3). The cap 32 is raised by the raising and lowering mechanism, so that the nozzle surface 20a of the recording head 20 of the carriage 15 comes into contact with the cap 32. The nozzle rows 31a to 31d (refer to FIG. 2) on the nozzle surface 20a are covered by the first case unit 45 (refer to FIG. 5) of the cap 32, and the nozzle row 31e (refer to FIG. 2) is covered by the second case unit 47 (refer to FIG. 5) of the cap 32. Here, the upper edges of the outer wall 41 and the partition wall 43 of the cap 32 are pressed against the nozzle surface 20a. The partition wall 43 is formed more elastically deformable than the outer wall 41. Thus, stress generated between the partition wall 43 of the cap 32 and the nozzle surface 20a is less than stress generated between the outer wall 41 of the cap 32 and the nozzle surface 20a. In other words, in the cleaning operation, the outer wall 41 preferentially comes in close contact with the nozzle surface 20a with larger stress, compared with the partition wall 43. As a result, the inner space of the cap 32 is effectively sealed from outside air. When the aspiration pump 36 is driven in this state, fluids in the inner space defined by the recording head 20 and the cap 32 are aspirated. As a result, the inner space is depressurized, so that color ink and reactive ink are aspirated out of the nozzle rows 31a to 31e on the nozzle surface 20a of the recording head 20. In this way, the ability of the recording head 20 to eject ink droplets is restored. The aspirated color ink is drained into the waste liquid tank 25 via the first case unit 45 and the aspiration tube 33. The aspirated reactive ink is drained into the waste liquid tank 25 via the second case unit 47 and the aspiration tube 34. With this cleaning operation, the color ink and the reactive ink are guided to the waste liquid tank 25 via separate routes, i.e., via a route including the case unit 45 and the aspiration tube 33, and a route including the case unit 47 and the aspiration tube 34, respectively. This prevents the color ink and the reactive ink from being mixed in the cap 32 or in the aspiration tubes. The color ink and the reactive ink do not react and do not coagulate in the cap 32 or in the aspiration tubes. Thus, cleaning efficiency is not degraded. Contrary to the first embodiment, the following considers the situation in which the outer wall 41 is formed more elastically deformable than the partition wall 43. In the cleaning operation in this case, the partition wall 43 preferentially comes in close contact with the nozzle surface 20a with larger stress, compared with the outer wall 41. In this state, the partition wall 43 exhibits high sealing performance to separate the first case unit 45 from the second case unit 47, whereas sealing performance of the outer wall 41 is lowered. The lowered sealing performance of the outer wall 41 makes it difficult to depressurize the inner space defined by the recording head 20 and the cap 32. Compared with the first embodiment, the cleaning efficiency is degraded in this case. In the first embodiment, the partition wall 43 is more elastically deformable than the outer wall 41. This structure gives preference to sealing between the outer wall 41 and the outside over sealing between the first case unit 45 and the second case unit 47. In this way, sealing between the cap 32 and the nozzle surface 20a is given appropriate preference depending on parts thereof. Stress generated between the partition wall 43 and the nozzle surface 20a is less than stress generated between the outer wall 41 and the nozzle surface 20a. With such a smaller stress, the partition wall 43 tends to exhibit low sealing performance. In other words, sealing between the partition wall 43 and the nozzle surface 20a may become less tight than sealing between the outer wall 41 and the nozzle surface 20a. However, the width L1 of the upper edge 41c of the outer wall 41 is less than the width L2 of the upper edge 43c of the partition wall 43 as shown in FIGS. 7 and 8. This means that the partition wall 43 more easily comes in close contact with the nozzle surface 20a than the outer wall 41. In this way, the shape of the upper edge 43c compensates for such low sealing performance of the partition wall 43. The first embodiment has the effects described below. (1) The cap 32 is brought into contact with the nozzle surface 20a of the recording head 20, so that the nozzle rows 31a to 31e are covered by the cap 32. The aspiration pump 36 is driven in this state, so that the inner pressure of the cap 32 is decreased, and ink is aspirated out of the nozzle rows 31a to 31e on the recording head 20. In this way, the cleaning operation is performed. The outer wall 41 comes into contact with the nozzle surface 20a with larger stress, compared with the partition wall 43. Thus, the outer wall 41 preferentially comes into contact with the nozzle surface 20a, compared with the partition wall 43. This structure ensures tight sealing between the outer wall 41 and the nozzle surface 20a. In this way, sealing performance of the outer wall 41 is given preference over sealing performance of the partition wall 43. Thus, the inner pressure of the cap 32 is sufficiently decreased, and the cleaning operation is reliably performed. The characteristic structure of the cap 32 improves the degree of sealing between the outer wall 41 and the nozzle surface 20a. Thus, the amount of energy required to drive the cap 32 does not need to be increased. This prevents an increase in the manufacturing cost or in the running cost of the printer 11. (2) The outer wall 41 and the partition wall 43 are formed by the core part 49 and the elastic part 51. When the cap 32 is brought into contact with the nozzle surface 20a, the elastic part 51 comes into contact with the nozzle surface 20a. This improves the degree of sealing between the cap 32 and the nozzle surface 20a. (3) The height H2 of the partition-wall resin part 43a is less than the height H1 of the outer-wall resin part 41a. Thus, the distance from the partition-wall resin part 43a to the nozzle surface 20a is greater than the distance from the outer-wall resin part 41a to the nozzle surface 20a when the cap 32 is into contact with the nozzle surface 20a. In this way, a relatively simple structure reliably enables the partition wall 43 to come into contact with the nozzle surface 20a with smaller stress compared with the outer wall 41. (4) The projection height h2 of the partition-wall elastic part 43b is greater than the projection height hi of the outer-wall elastic part 41b. In other words, the partition-wall elastic part 43b has a greater thickness, in the direction of contact with the nozzle surface 20a, than the outer-wall elastic part 41b. With the elastic part 51 of the partition wall 43 being thicker than the elastic part 51 of the outer wall 41, the partition wall 43 is more elastically deformable than the outer wall 41. In this way, a relatively simple structure reliably enables the partition wall 43 to come into contact with the nozzle surface 20a with smaller stress compared with the outer wall 41, when the cap 32 is brought into contact with the nozzle surface 20a. (5) The upper edges 41c and 43c of the elastic parts 41b and 43b form flat planar surfaces parallel to the bottom surface 38. The width L1 of the upper edge 41c of the outer-wall elastic part 41b is less than the width L2 of the upper edge 43c of the partition-wall elastic part 43b. This structure increases the degree of contact between the partition wall 43 and the nozzle surface 20a when the cap 32 is brought into contact with the nozzle surface 20a. With the partition wall 43 having a smaller stress on the nozzle surface 20a than the outer wall 41, the partition wall 43 tends to exhibit low sealing performance. In other words, sealing between the partition wall 43 and the nozzle surface 20a may become less tight than sealing between the outer wall 41 and the nozzle surface 20a. However, the increased degree of contact compensates for such low sealing performance of the partition wall 43. The following describes a liquid ejecting apparatus according to a second embodiment of the present invention, with reference to FIGS. 9 to 14. The liquid ejecting apparatus of the second embodiment has the same structure as the printer 11 of the first embodiment except for components corresponding to the partition wall 43 and the aspiration mechanism of the printer 11 of the first embodiment. The following describes differences between the second embodiment and the first embodiment. As shown in FIG. 10, a cap 32 is formed substantially as a case having a top opening. A partition wall 43 extends in a sub-scanning direction Y, to connect two facing surfaces of an outer wall 41 extending in a scanning direction X. The partition wall 43 separates a first case unit 45 at left of the partition wall 43 and a second case unit 47 at right of the partition wall 43 in FIG. 10. As shown in FIG. 12, the partition wall 43 includes a partition-wall resin part 43a, which is continuous to a bottom surface 38 of the cap 32. Height H3 of the partition-wall resin part 43a, i.e., distance from the bottom surface 38 to the upper edge of the resin part 43a, is uniform in the sub-scanning direction Y. The height H3 is less than the height H2 of the partition-wall resin part 43a in the first embodiment. As shown in FIG. 12, the upper edge and the side surface of the partition-wall resin part 43a are covered by a partition-wall elastic part 43b. The partition-wall elastic part 43b projects from the upper edge of the partition-wall resin part 43a by height h4 as shown in FIG. 13. In other words, distance from the upper edge of the partition-wall resin part 43a to the upper edge of the partition-wall elastic part 43b is the height h4. The projection height h4 is greater than the projection height hl (refer to FIG. 7) of the outer-wall elastic part 41b. Distance from the bottom surface 38 to the upper edge of the outer-wall elastic part 41b is equal to the distance from the bottom surface 38 to the upper edge of the partition-wall elastic part 43b. As shown in FIGS. 10 and 11, the partition-wall elastic part 43b has a cut part, i.e., a step part 60, in its middle vicinity as viewed in the sub-scanning direction Y. The step part 60 is formed by partially cutting the upper edge of the partition-wall elastic part 43b. As shown in FIGS. 12 and 13, in the same manner as the partition-wall elastic part 43b, the step part 60 is tapered to its upper edge 60a (in the direction of the nozzle surface 20a). As shown in FIG. 13, the step part 60 of the partition-wall elastic part 43b projects from the upper edge of the partition-wall resin part 43a by height h3. The projection height h3 of the step part 60 of the partition-wall elastic part 43b is less than the projection height h4 of the part of the partition-wall elastic part 43b other than the step part 60. The projection height h3 is determined so that the upper edge 60a of the step part 60 does not come into contact with the nozzle surface 20a when the outer-wall elastic part 41b is brought into contact with and pressed against the nozzle surface 20a. The projection height h3 is determined so that the upper edge 60a projects from top surfaces (surfaces closer to the nozzle surface 20a) of a first and second ink absorbing sheets 45a and 47a (refer to FIG. 12), which are placed in the first and second case units 45 and 47, respectively. When the upper edge of the outer wall 41 (the outer-wall elastic part 41b) is brought into contact with and pressed against the nozzle surface 20a by a raising and lowering mechanism, the upper edge of the partition-wall elastic part 43b is also brought into contact with and pressed against the nozzle surface 20a at the same time. This causes a first partitioned chamber S1 and a second partitioned chamber S2 respectively corresponding to the first and second case units 45 and 47 to be sealed between the cap 32 and the nozzle surface 20a as shown in FIG. 14. Here, the step part 60 and the nozzle surface 20a define a connection path 61, which connects the first and second partitioned chambers S1 and S2 with each other. The connection path 61 facilitates elastic deformation of the partition-wall elastic part 43b, which is pressed against the nozzle surface 20a. To be specific, a portion of the partition-wall elastic part 43b is deformed elastically toward the connection path 61 (the step part 60). When the outer-wall elastic part 41b is pressed against the nozzle surface 20a as shown in FIG. 14, a portion of the partition-wall elastic part 43b is deformed elastically toward the connection path 61. This elastic deformation decreases stress placed on the nozzle surface 20a by the partition-wall elastic part 43b. This enables the partition wall 43 to be pressed against the nozzle surface 20a with smaller stress, compared with the outer wall 41. As shown in FIG. 9, two aspiration tubes 33 and 34 are respectively connected to a first and second drain outlets 53 and 55 (refer to FIG. 11), which are formed in the bottom surface 38 of the cap 32. A waste liquid tank 25 has a left space 25a and a right space 25b divided at both sides of a set of waste liquid absorbing members 31 placed in the waste liquid tank 25. The aspiration tube 33 connects the first partitioned chamber S1 to the left space 25a. The aspiration tube 34 connects the second partitioned chamber S2 to the right space 25b. A first aspiration pump 36a is arranged midway on the aspiration tube 33. A second aspiration pump 36b is arranged midway on the aspiration tube 34. The first and second aspiration pumps 36a and 36b aspirate various fluids flowing upstream of the aspiration tubes 33 and 34, such as air and ink, to depressurize the first and second partitioned chambers S1 and S2. When the first and second partitioned chambers S1 and S2 are depressurized, the outer wall 41 (the outer-wall elastic part 41b) preferentially comes in close contact with the nozzle surface 20a, and the partition wall 43 comes into contact with the nozzle surface 20a with smaller stress compared with the outer wall 41. As a result, the inner space of the cap 32 (the first and second partitioned chambers S1 and S2) is effectively sealed from outside air. The first and second partitioned chambers S1 and S2 are connected by the connection path 61. This means that the first and second partitioned chambers S1 and S2 have the same pressure. Color ink and reactive ink are aspirated by a capacity according to negative pressure of the first and second partitioned chambers S1 and S2. In other words, the color ink and the reactive ink are aspirated by substantially the same capacity. The aspirated color ink and the aspirated reactive ink are absorbed by the first and second ink absorbing sheets 45a and 47a, respectively. The aspirated color ink and the aspirated reactive ink are drained from the first and second partitioned chambers S1 and S2 into the left space 25a and the right space 25b of the waste liquid tank 25 as fluids containing air, via the aspiration tubes 33 and 34, respectively. The color ink and the reactive ink drained into the waste liquid tank 25 are absorbed by the waste liquid absorbing members 31 while spreading from both ends toward middle of the waste liquid absorbing members 31. In this way, the color ink and the reactive ink aspirated in the first and second partitioned chambers S1 and S2 reach substantially the middle position of the waste liquid absorbing members 31 without being mixed with each other, and are stored in the waste liquid tank 25. The second embodiment has the effects described below. (1) The step part 60 of the partition wall 43 (the partition-wall elastic part 43b) forms the connection path 61, which connects the first and second partitioned chambers S1 and S2 in the cleaning operation. The connection path 61 allows a portion of the partition-wall elastic part 43b, which is pressed against the nozzle surface 20a, to be deformed elastically toward the connection path 61 (the step part 60). Such elastic deformation of the partition-wall elastic part 43b causes stress put on the nozzle surface 20a by the partition wall 43 to be less than stress put on the nozzle surface 20a by the outer wall 41. Thus, the outer wall 41 preferentially comes in close contact with the nozzle surface 20a compared with the partition wall 43. This effectively ensures tight sealing between the outer wall 41 and the nozzle surface 20a. As a result, the inner pressure of the cap 32 is sufficiently decreased. The cleaning operation is reliably performed without increasing the amount of energy required to drive the raising and lowering mechanism for raising the cap 32, etc. (2) The connection path 61 enables the first and second partitioned chambers S1 and S2 to have an equivalent inner pressure. Thus, the first and second partitioned chambers S1 and S2 are depressurized to substantially the same pressure. This enables the amount of color ink aspirated into the first partitioned chamber S1 and the amount of reactive ink aspirated into the second partitioned chambers S2 to be substantially the same. Also, cleaning failures caused by insufficient aspirating of ink are reduced. (3) Ink aspirated in the first partitioned chamber S1 and ink aspirated in the second partitioned chamber S2 are separately drained into the left space 25a and the right space 25b of the waste liquid tank 25 by the aspiration pumps 36a and 36b and the aspiration tubes 33 and 34, respectively. In this way, the color ink and the reactive ink are drained out via separate routes. Thus, the color ink and the reactive ink are not mixed and do not coagulate during aspirating. The color ink and the reactive ink are reliably absorbed by the waste liquid absorbing members 31. As a result, the aspirating ability of the cleaning mechanism 27 is not degraded, and the cleaning operation is performed more reliably. It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the present invention may be embodied in the following forms. The distance from the bottom surface 38 to the upper edge of the outer-wall elastic member 41b may be greater than the distance from the bottom surface 38 to the upper edge of the partition-wall elastic part 43b. In other words, the distance between the partition wall 43 and the nozzle surface 20a may be greater than the distance between the outer wall 41 and the nozzle surface 20a when the cap 32 is not into contact with the nozzle surface 20a. The partition-wall elastic part 43b may come into contact with the nozzle surface 20a when the outer-wall elastic member 41b is into contact with the nozzle surface 20a. Alternatively, the partition-wall elastic part 43b may be spaced from the nozzle surface 20a when the outer-wall elastic part 41b comes into contact with the nozzle surface 20a. In this case, a simple structure, with only the height of the partition wall 43 being changed, more reliably enables stress put on the nozzle surface 20a by the partition wall 43 to be less than stress put on the nozzle surface 20a by the outer wall 41. The shape of the partition wall 43 may be modified so that the distance between the partition wall 43 and the nozzle surface 20a becomes smaller at locations closer to the outer wall 41 when the cap 32 is not into contact with the nozzle surface 20a. An upper surface of the partition wall 43 may include an inclined surface (straight or arch) that gradually increases in height toward the outer wall 41. The partition wall 43 has a greater distance from the nozzle surface 20a at locations farther from the outer wall 41. When the cap 32 is brought into contact with the nozzle surface 20a, a middle part of the cap 32 is easily stress-deformed in the direction of the nozzle surface 20a. However, this structure enables stress between the partition wall 43 and the nozzle surface 20 to be maintained small regardless of such stress-deformation. Thus, sealing performance of the outer wall 41 is more reliably provided. The pressing force of the partition wall 43 and of the outer wall 41 against the nozzle surface 20a may be adjusted by adjusting the thickness of the outer wall 41 and of the partition wall 43. As shown in FIGS. 15 and 16, for example, thickness W2 of the partition wall 43 may be set less than thickness W1 of the outer wall 41. In this case, a simple structure with the partition wall 43 being thinner than the outer wall 41 enables desired effects to be obtained. An angle formed by each of two inclined side surfaces that define the tapered upper edge of the outer-wall elastic part 41b and a plane vertical to the bottom surface 38 is assumed to be an inclined angle θ1. An angle formed by each of two inclined side surfaces that define the tapered upper edge of the partition-wall elastic part 43b and the plane vertical to the bottom surface 38 is assumed to be an inclined angle θ2. In this case, the inclined angle θ2 may be set smaller than the inclined angle θ1, so that the thickness W2 of the partition wall 43 becomes substantially less than the thickness W1 of the outer wall 41. Such a simple structure also enables desired effects to be obtained. In the first embodiment, the height H2 of the resin part 43a is less than the height H1 of the resin part 41a. The relationship between the heights H1 and H2 may be changed as long as stress generated between the partition wall 43 and the nozzle surface 20a is less than stress generated between the outer wall 41 and the nozzle surface 20a. In the second embodiment, the height H3 of the partition-wall resin part 43a may be, for example, the same as the height H2, or may be greater than the height H1 of the outer-wall resin part 41a. The height H3 may be appropriately determined so that stress put on the nozzle surface 20a by the partition wall 43 is less than stress put on the nozzle surface 20a by the outer wall 41, and that the connection path 61 is formed. The relationship between the projection height h2 of the elastic part 43b and the projection height hl of the elastic part 41b may be changed as long as stress generated between the partition wall 43 and the nozzle surface 20a is less than stress generated between the outer wall 41 and the nozzle surface 20a when the cap 32 comes into contact with the nozzle surface 20a. The width L1 of the upper edge 41c of the elastic part 41b may be equal to or greater than the width L2 of the upper edge 43c of the elastic part 43b. The shapes of the upper edges 41c and 43c may be other than the flat planar surfaces parallel to the bottom surface 38. In the above embodiments, the elastic parts 41b and 43b, and the step part 60 taper off in the direction of the nozzle surface 20a. At least one of the elastic parts 41b and 43b, and the step part 60 may not taper off. In the above embodiments, the cap 32 has one partition wall 43 that divides the inner space of the cap 32 into two. The cap 32 may have two or more partition walls 43 that divide the inner space into three or more. In this case, the partition walls 43 are formed so that stress between each partition wall 43 and the nozzle surface 20a is less than stress between the outer wall 41 and the nozzle surface 20a when the cap 32 is brought into contact with the nozzle surface 20a. Here, aspiration pumps and aspiration tubes corresponding in one-to-one to chambers partitioned by the partition walls 43 may be arranged, and each partitioned chamber may be aspirated by an independent aspiration pump and an independent aspiration tube. The partition wall 43 should not be limited to the linear shape in the sub-scanning direction Y, but may be other shapes such as a curved shape or a linear shape perpendicular to the sub-scanning direction Y. In the second embodiment, the upper edge 60a of the step part 60 projects from the top surfaces of the first and second ink absorbing sheets 45a and 47a as shown in FIG. 13. The present invention should not be limited to such a structure. For example, the upper edge 60a of the step part 60 may be at the same level as the top surfaces of the first and second ink absorbing sheets 45a and 47a, or may be at a lower level than the top surfaces of the first and second ink absorbing sheets 45a and 47a. The projection height h3 of the step part 60 is determined so that the first and second ink absorbing sheets 45a and 47a placed in the cap 32 do not overlap with each other, and that the upper edge 60a of the step part 60 does not come into contact with the nozzle surface 20a. In the second embodiment, the partition-wall resin part 43a has the height H3, which is uniform in the sub-scanning direction Y. However, for example, a middle vicinity part of the partition-wall resin part 43a in the sub-scanning direction Y may be formed to have a smaller height than the other parts, according to the shape of the step part 60. In the second embodiment, the partition-wall elastic part 43b has one step part 60 in its middle in the sub-scanning direction Y. The present invention should not be limited to such a structure. For example, the partition-wall elastic part 43b may have the step part 60 at one end, or may have a plurality of step parts 60 in the sub-scanning direction Y. The position, number, and shape of the step part(s) 60 may be freely determined as long as the step part 60 forms the communication path 60 and allows a portion of the partition-wall elastic part 43b to be elastically deformed in the direction of the communication path 60. As shown in FIG. 17, the step part 60 may be formed along the entire length of the partition-wall elastic part 43b. In this case, no stress is generated between the partition wall 43 and the nozzle surface 20a when the outer wall 41 is pressed against the nozzle surface 20a. The outer-wall elastic part 41b reliably comes in close contact with the nozzle surface 20a. The connection path 61 may not be defined by the step part 60 and the nozzle surface 20a. For example, instead of the connection path 61, a through-hole 61a may be formed in the partition wall 43 to connect the first partitioned chamber S1 and the second partitioned chamber S2 as shown in FIG. 18. In the second embodiment, the step part 60 (the upper edge 60a) is formed in the partition-wall elastic part 43b. The present invention should not be limited to such a structure. The step part 60 may be formed in the partition-wall resin part 43a. In the second embodiment, the first and second partitioned chambers S1 and S2 are aspirated by the independent aspiration pumps 36a and 36b, respectively. The first and second partitioned chambers S1 and S2 may be aspirated by the integral-type aspiration pump 36 as in the first embodiment. In the second embodiment, the aspiration tubes 33 and 34 are arranged to deliver fluids to the common set of waste liquid absorbing members 31. However, two sets of waste liquid absorbing members 31 respectively corresponding to the aspiration tubes 33 and 34 may be arranged as spaced from each other in the waste liquid tank 25. The aspiration tubes 33 and 34 respectively deliver fluids to the two sets of waste liquid absorbing members 31 via separate routes. Thus, color ink and reactive ink do not react and do not coagulate in the waste liquid absorbing members 31. This reliably prevents the aspiration ability of the cleaning mechanism 27 from being degraded. The first and second case units 45 and 47 of the cap 32 correspond to color ink and reactive ink, respectively. However, the first and second case units 45 and 47 may correspond to other kinds of ink. For example, the first case unit 45 may correspond to pigment ink, and the second case unit 57 may correspond to dye ink. The liquid ejecting apparatus of the present invention should not be limited to the printer 11 for ejecting ink (and printing apparatuses such as a facsimile and a copier), but may be embodied as liquid ejecting apparatuses for ejecting other liquids. For example, the liquid ejecting apparatus of the present invention may be an apparatus for ejecting such liquids as an electrode material and a color material for use in an LCD (liquid crystal display), an EL (electroluminescence) display, or a surface emitting display. Also, the liquid ejecting apparatus of the present invention may be an apparatus for ejecting living organisms for use in manufacturing bio tips, or may be a sample ejecting apparatus, such as a precision pipette. The present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.
|
B
|
B41
|
B41J
|
21
|
65
|
|||
11904666
|
US20090086951A1-20090402
|
Telecommunications endpoint for managing multi-conferencing
|
ACCEPTED
|
20090318
|
20090402
|
[]
|
H04M342
|
["H04M342"]
|
7995733
|
20070928
|
20110809
|
379
|
204010
|
75232.0
|
SMITH
|
CREIGHTON
|
[{"inventor_name_last": "Geppert", "inventor_name_first": "Birgit A.", "inventor_city": "Basking Ridge", "inventor_state": "NJ", "inventor_country": "US"}, {"inventor_name_last": "Roessler", "inventor_name_first": "Frank M.", "inventor_city": "Basking Ridge", "inventor_state": "NJ", "inventor_country": "US"}]
|
An apparatus or endpoint device is disclosed for providing the capability to simultaneously manage multiple conference calls, move participants in the conference calls from one conference call to another and subdivide or join multiple conference calls together, and the like, wherein the apparatus or endpoint device provides a multi-conferencing capability that enables one or more teleconferencing participants to manage multiple teleconferences simultaneously. Each participant in the teleconference call manages their respective teleconference through their apparatus or endpoint device at their specific location by using it to adjust the teleconferencing topology, i.e., who should form what part of each specific teleconference call.
|
1. An apparatus for permitting a user to simultaneously manage multiple conference calls, comprising: a display positioned on a surface of the apparatus, said display providing an indication of available conferencing functions or a conference topology; a mechanism located on a body of the apparatus for permitting selection of the conferencing functions, the mechanism permitting navigation between the indicated available functions and the conference topology; and a plurality of keys arranged on the body of the apparatus for activating function indicators shown on the display, said function indicators being activated upon engagement of a corresponding one of said plural keys. 2. The apparatus of claim 1, wherein the mechanism is a thumb-dial mechanism. 3. The apparatus of claim 2, wherein the thumb-dial mechanism comprises a central button and a plurality of buttons that permit access and selection of conferencing functions displayed on the display, respectively. 4. The apparatus of claim 1, wherein the conferencing functions include at least one of a multi-conference indication section, a confirm topology indication section, a contacts indication section and a select contacts indication section. 5. The apparatus of claim 1, wherein the display includes a section for providing indicators of at least one of active and selectable conferences. 6. The apparatus of the claim 1, wherein the function indicators comprise at least one of conf, Add, Delete, Drop, Cancel, Host, Move, More, OK and Rename. 7. The apparatus of claim 1, wherein said conference topology provides an indication of who should form what part of each specific teleconference call. 8. The apparatus of claim 1, wherein each participant in a teleconference call manages their respective teleconference through their apparatus at their specific location by adjusting the teleconferencing topology. 9. The apparatus of claim 1, wherein the apparatus is a graphical user interface. 10. The apparatus of claim 9, wherein the graphical user interface comprises a telecommunications endpoint device. 11. The apparatus of claim 1, wherein the apparatus is a desktop device. 12. The apparatus of claim 10, wherein the telecommunications endpoint device is a desktop device. 13. The apparatus of claim 1, wherein the apparatus permits splitting of a teleconference call into multiple teleconference calls. 14. The apparatus of claim 13, wherein the display provides an indication that the teleconference has been split into multiple conference calls. 15. The apparatus of the claim 13, wherein the split conference call is the conference topology. 16. The apparatus of claim 1, wherein all participants in a conference call are displayed on the apparatus at a respective location of each participant in the conference call.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention The present invention generally relates to the field of teleconferencing and, more particularly, to an apparatus or endpoint device for permitting conference call participants to simultaneously manage multiple conference calls. 2. Description of the Related Art In a conventional teleconferencing system that utilizes a conference bridge, a group of people individually call the conference bridge assigned to the specific conference for a particular time slot and add themselves to the initial conference call. During the call, a specific participant can remove themselves from the conference bridge, and new participants are able to join the conference call that is currently in progress. When a new participant wishes to join the conference, the new participant will not be informed about who is currently at the bridge, i.e., the new participant will not be provided with the identity of the participants in the conference call. In addition, the conference call participants will not be provided with automatic updates with respect to who is currently participating in the ongoing conference call, i.e., who has joined or left the conference. The only notification that is currently provided is a nondescript audible alert. If a participant wants to participate in a second conference call, the participant is required to “drop” from the first call and dial into the second conference call. Alternatively, the participant may switch to a second call via their phone (i.e., utilize the conventional call waiting feature) to access the second conference call, while remaining connected to the original conference. However, through all of the foregoing connection cycles, each call has a well-defined “life cycle”, which involves a number of steps. First, the conference call is scheduled by a specific person, who then distributes the dial-in information to others who wish to participate in the conference call. Second, conference call participants call and add themselves to the conference bridge to participate in the conference call, and then add themselves to the conference call using the dial-in information provided in the distributed dial-in information. Next, the user places the call. Finally, participants in the conference call drop from the call or the allotted time for the call expires. In any event, the end of the conference call does eventually occur. In such a scenario, it is not possible to spontaneously extend the duration of the conference or to split up and create a sidebar conference between a subset of participants without having reserved an additional conference bridge prior to attempting to establish the sidebar conference or without needing to call the bridge operator for assistance with setting up the additional conference calls. In other conventional systems, a caller is able to conference with several people by using his or her calling device as a local conference bridge. However, the number of participants in such a system is typically limited to no more than approximately six participants, where each participant must be added to the conference one after the other. In addition, the conference call itself is still “anchored” to a single, controlling calling device, i.e., the device being used as the bridge. In either case, the conference bridge paradigm is rigidly constrained to a situation in which people dial into the conference and from which people are “dropped” from the conference. There are no known products that provide features and the ability to control conference calls that overcome the foregoing limitations of the above-described conventional systems. Accordingly, there is a need for an apparatus that provides the capability to simultaneously manage multiple conference calls from the endpoint, move participants in the conference calls from one conference call to another and subdivide or join multiple conference calls together.
|
<SOH> SUMMARY OF THE INVENTION <EOH>An apparatus or endpoint device is disclosed for providing the capability to simultaneously manage multiple conference calls, move participants in the conference calls from one conference call to another and subdivide or join multiple conference calls together. In particular, the proposed apparatus or endpoint device provides a multi-conferencing capability that allows one or more teleconferencing participants to manage multiple teleconferences simultaneously. Here, each participant in the teleconference call manages their respective teleconference through their apparatus or endpoint device at their specific location by using it to adjust the teleconferencing topology, i.e., who should form what part of each specific teleconference call. A participant seeking to initiate a conference call does so at his or her endpoint device by selecting a conference call identifier, where the identifier identifies a conference call to be created. The initiating participant then selects the participants to be associated with the particular call and confirms the selection. Upon confirmation of the selection, the conference call among the selected participants is established. In the preferred embodiment, the endpoint device is a graphical user interface (GUI) that comprises a telecommunications endpoint device that enables multi-conferencing in a desktop environment. The endpoint device in accordance with one embodiment of the present invention provides symmetric control, in that any participant has at least some control over how the creation and evolution of the conference calls progress. By providing each participant with the capability to control the creation and evolution of a conference call, each participant is permitted to move freely from one conference call to another. That is, each participant at his or her endpoint device has the ability to “shape” their conference calls to suit their changing needs during the calls. In other words, each participant may split, merge, add, and delete one or more conference calls that may be in progress. In addition, each participant may re-add, re-drop, and remove participants of conferences calls to suit the needs of each of the participants. The multi-conferencing capability of the present invention permits the management of multiple conferences simultaneously, as well as the splitting and merging of conference calls. In addition, symmetric control at the various participating endpoints is provided, as well as a smooth transition of conference participants from one call to another. Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are exemplary and designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
|
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to the field of teleconferencing and, more particularly, to an apparatus or endpoint device for permitting conference call participants to simultaneously manage multiple conference calls. 2. Description of the Related Art In a conventional teleconferencing system that utilizes a conference bridge, a group of people individually call the conference bridge assigned to the specific conference for a particular time slot and add themselves to the initial conference call. During the call, a specific participant can remove themselves from the conference bridge, and new participants are able to join the conference call that is currently in progress. When a new participant wishes to join the conference, the new participant will not be informed about who is currently at the bridge, i.e., the new participant will not be provided with the identity of the participants in the conference call. In addition, the conference call participants will not be provided with automatic updates with respect to who is currently participating in the ongoing conference call, i.e., who has joined or left the conference. The only notification that is currently provided is a nondescript audible alert. If a participant wants to participate in a second conference call, the participant is required to “drop” from the first call and dial into the second conference call. Alternatively, the participant may switch to a second call via their phone (i.e., utilize the conventional call waiting feature) to access the second conference call, while remaining connected to the original conference. However, through all of the foregoing connection cycles, each call has a well-defined “life cycle”, which involves a number of steps. First, the conference call is scheduled by a specific person, who then distributes the dial-in information to others who wish to participate in the conference call. Second, conference call participants call and add themselves to the conference bridge to participate in the conference call, and then add themselves to the conference call using the dial-in information provided in the distributed dial-in information. Next, the user places the call. Finally, participants in the conference call drop from the call or the allotted time for the call expires. In any event, the end of the conference call does eventually occur. In such a scenario, it is not possible to spontaneously extend the duration of the conference or to split up and create a sidebar conference between a subset of participants without having reserved an additional conference bridge prior to attempting to establish the sidebar conference or without needing to call the bridge operator for assistance with setting up the additional conference calls. In other conventional systems, a caller is able to conference with several people by using his or her calling device as a local conference bridge. However, the number of participants in such a system is typically limited to no more than approximately six participants, where each participant must be added to the conference one after the other. In addition, the conference call itself is still “anchored” to a single, controlling calling device, i.e., the device being used as the bridge. In either case, the conference bridge paradigm is rigidly constrained to a situation in which people dial into the conference and from which people are “dropped” from the conference. There are no known products that provide features and the ability to control conference calls that overcome the foregoing limitations of the above-described conventional systems. Accordingly, there is a need for an apparatus that provides the capability to simultaneously manage multiple conference calls from the endpoint, move participants in the conference calls from one conference call to another and subdivide or join multiple conference calls together. SUMMARY OF THE INVENTION An apparatus or endpoint device is disclosed for providing the capability to simultaneously manage multiple conference calls, move participants in the conference calls from one conference call to another and subdivide or join multiple conference calls together. In particular, the proposed apparatus or endpoint device provides a multi-conferencing capability that allows one or more teleconferencing participants to manage multiple teleconferences simultaneously. Here, each participant in the teleconference call manages their respective teleconference through their apparatus or endpoint device at their specific location by using it to adjust the teleconferencing topology, i.e., who should form what part of each specific teleconference call. A participant seeking to initiate a conference call does so at his or her endpoint device by selecting a conference call identifier, where the identifier identifies a conference call to be created. The initiating participant then selects the participants to be associated with the particular call and confirms the selection. Upon confirmation of the selection, the conference call among the selected participants is established. In the preferred embodiment, the endpoint device is a graphical user interface (GUI) that comprises a telecommunications endpoint device that enables multi-conferencing in a desktop environment. The endpoint device in accordance with one embodiment of the present invention provides symmetric control, in that any participant has at least some control over how the creation and evolution of the conference calls progress. By providing each participant with the capability to control the creation and evolution of a conference call, each participant is permitted to move freely from one conference call to another. That is, each participant at his or her endpoint device has the ability to “shape” their conference calls to suit their changing needs during the calls. In other words, each participant may split, merge, add, and delete one or more conference calls that may be in progress. In addition, each participant may re-add, re-drop, and remove participants of conferences calls to suit the needs of each of the participants. The multi-conferencing capability of the present invention permits the management of multiple conferences simultaneously, as well as the splitting and merging of conference calls. In addition, symmetric control at the various participating endpoints is provided, as well as a smooth transition of conference participants from one call to another. Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are exemplary and designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other advantages and features of the invention will become more apparent from the detailed description of the preferred embodiments of the invention given below with reference to the accompanying drawings in which: FIG. 1 is an exemplary graphical diagram illustrating the implementation of the apparatus or endpoint device in accordance with an embodiment of the invention pursuant to creating a simultaneous management of multiple conference calls; FIGS. 1(a) thru 1(r) are exemplary illustrations of the display area of the apparatus or endpoint device provided to a user for creating the multiple conference calls; FIG. 2 is an exemplary graphical illustration of a conference call between multiple users of the apparatus or endpoint device of the invention; FIG. 2(a) is an exemplary illustration of the display area of the apparatus or endpoint device provided to the users pursuant to creation of the conference call; FIG. 3 is an exemplary graphical illustration of the extension or addition of an additional participant to the conference call; FIG. 3(a) thru 3(j) are exemplary illustrations of the display area of the apparatus or endpoint device provided to the users pursuant to the extension or addition of an additional participant to the conference call; FIG. 4 is an exemplary graphical illustration of the apparatus or endpoint device in the extended conference call; FIG. 4(a) thru 4 is an exemplary illustration of the display area of the apparatus or endpoint device provided to the users during the extended conference call; FIG. 5 is an exemplary graphical illustration of the generation of a split of the conference call into multiple conference calls; FIGS. 5(a) thru 5(p) are exemplary illustrations of the display area of the apparatus or endpoint device provided to the users pursuant to the split of the conference call into multiple conference calls; FIG. 6 is a graphical illustration of multiple conference calls in accordance with an embodiment of the invention; FIG. 6(a) is an exemplary illustration of the display area of the apparatus or endpoint device provided to the users when the conference call is split into multiple conference calls; FIG. 7 is a graphical illustration of the display area of the apparatus or endpoint device provided to the users pursuant to moving a participant into a new conference call that is created by dividing an existing conference call; FIG. 7(a) thru 7(k) are exemplary illustrations of the display area of the apparatus or endpoint device provided to the users pursuant to moving the participant into a new conference call that is created by dividing an existing conference call; FIG. 8 is an exemplary graphical illustration of the conference call into which the participant has been moved; and FIG. 8(a) an exemplary illustration of the display area of the apparatus or endpoint device provided to the users in the conference call into which the participant has been moved. DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS An apparatus or endpoint device is disclosed for providing the capability to simultaneously manage multiple conference calls, move participants in the conference calls from one conference call to another and subdivide or join multiple conference calls together. In particular, the proposed inventive apparatus or endpoint device provides a multi-conferencing capability that allows one or more teleconferencing participants to manage multiple teleconferences simultaneously. Here, each participant in the teleconference call manages their respective teleconference through their apparatus or endpoint device at their specific location by using it to adjust the teleconferencing topology, i.e., who should form what part of each specific teleconference call. In contrast to the previously discussed conventional systems for providing teleconferencing, the multi-conferencing capability provided by the apparatus or endpoint device in accordance with the invention, departs from the rigid conference bridge paradigm associated with such conventional systems. Instead, the multi-conferencing provided by the apparatus or endpoint device enables conference call participants to manage multiple conferences simultaneously. A participant seeking to initiate a conference call does so at his or her endpoint device by selecting a conference call identifier, where the identifier identifies a conference call to be created. The initiating participant then selects the participants to be associated with the particular call and confirms the selection. Upon confirmation of the selection, the conference call among the selected participants is established. In the preferred embodiment, the endpoint device is a graphical user interface (GUI) that comprises a telecommunications endpoint device which allows multi-conferencing in a desktop environment. In an embodiment, the endpoint device is alphanumeric based and implemented in a Spark-based environment, which is implemented in a peer-to-peer environment to provide interactive communication with the endpoint device or GUI. In alternative embodiments, the endpoint device or GUI is icon based. The endpoint device of the present invention provides symmetric control, in that any participant has at least some control over how the creation and evolution of the conference calls progress. By providing each participant with the capability to control the creation and evolution of a conference call, each participant is permitted to move freely from one conference call to another. That is, each participant at his or her endpoint device has the ability to “shape” their conference calls to suit their changing needs during the calls. In other words, each participant may split, merge, add, and delete one or more conference calls that may be in progress. In addition, each participant may re-add, re-drop, and remove participants of conferences calls to suit the needs of each of the participants. FIG. 1 is an exemplary graphical diagram illustrating implementation of the apparatus or endpoint device in accordance with an embodiment of the invention. In accordance with the exemplary embodiment, a conference call is established among a team of employees of a company. Such a conference call can be established in the manner disclosed in co-pending U.S. application Ser. No. 11/______, titled Multi-Conferencing Capability, filed Sep. 28, 2007 (Attorney Docket No. 5123-58), the contents of which are incorporated herein in its entirety. With reference to FIG. 1, a first participant H at a first endpoint seeks to create a first conference call that involves a second participant P and a third participant D to discuss a new product, for example. Using her apparatus or endpoint device 100, which shows potential participants P and D, participant H selects the first conference call and participants P and D, and creates the call. In one embodiment, the apparatus or endpoint device comprises a Graphical User Interface (GUI). As shown in FIG. 1(a), the display 110 of the apparatus or endpoint device changes to provide an indication that the creation of a conference call is possible. The user or participant H begins establishment of the conference call by using a first input section that comprises a thumb-dial mechanism 112, or the like. In the illustrated configuration, the thumb-dial mechanism 112 comprises a central button 112a that permits a user to access selectable functions that are displayed on the display 110 of the apparatus or endpoint device 100. A group of buttons 112b, 112c, 112d, 112e is also provided in the thumb-dial mechanism 112 for permitting navigation between the indicated available functions, such as first function indicator 115 and a second function indicator 120 of the display. With additional reference to FIG. 1(a), the first function indicator 115 and the second function indicator 120 are shown on display 110 of the apparatus or endpoint 100. Located at the lower section of the display are the selection areas, such as M-Conf 130 and Send All 140 that indicate the functions that may be currently selected. In the present configuration of the display 110, each of these functions are activated when the user engages any one of the keys 130′ or 145′, respectively. There is no selectable function associated with selection areas 135 and 145. Consequently, these selection areas are blank. It should be appreciated that the selectable functions will vary based on the indication in each selection area 130, 135, 140, 145 shown in the lower section of the display 110 of the endpoint device 100. Each of the selectable functions are thus activated or selected when participant H engages any one of key 130′, key 135′, key 140′ or key 145′, respectively. Upon first participant H using the thumb-dial mechanism 112 to select the selection area M-Conf 130, the display 110 of the apparatus or endpoint device 100 changes or becomes updated, as shown in FIG. 1(b). Here, the first function indicator 115 and the second function indicator 120 respectively indicate that a multi-conference may be established and that the multi-conference is empty or there are no participants selected for the conference. In addition, the selection area 130, 135, 140, 145 shown in the lower section of the display 110 of the endpoint device 100 indicates the functions Add 130, Delete 135, OK 140 and Rename 145. Each of these function are activated when participant H engages any one of key 130′, key 135′, key 140′ or key 145′, respectively. After participant H uses the thumb-dial mechanism 112 to indicate the desire to add a potential participant to the conference call, the display 110 of the apparatus or endpoint device 100 changes or becomes updated, as shown in FIG. 1(c). Here, the first conference is indicated by the Conference 1 section 125 of the display. In addition, the first function indicator 115 and the second function indicator 120 indicate that a multi-conference may be established and that the user should confirm the conference topology, respectively. After participant H uses the thumb-dial mechanism 112 to confirm the conference call topology, the display 110 of the apparatus or endpoint device 100 changes or becomes updated, as shown in FIG. 1(d). Here, the first conference is indicated by the Conference 1 section 125 of the display. In addition, the first function indicator 115 and the second function indicator 120 indicate that a multi-conference is established and that the conference is empty, respectively. Next, participant H indicates the desire to add another participant by using either keys 130′ thru 145′ or the thumb-dial mechanism 112 to add and/or select another participant, where the display 110 of the apparatus or endpoint device 100 changes or becomes updated, as shown in FIG. 1(e). Here, the first function indicator 115 and the second function indicator 120 indicate that a list of contacts is available and that a contact from the list of contacts may be selected, respectively. In addition, the phone extensions of the contacts, such as 5104 (H), 5105 (P), 5106 (D) and 5107 (J), are shown on the display. It should be readily apparent that the thumb-dial mechanism 112 may be used to navigate and select each user associated with a particular phone extension from among the list presented on the display 110 of the apparatus or endpoint device 100. Moreover, it should be readily appreciated that the number of phone contacts could readily be more or less than what is currently shown. Participant H then selects herself for addition to the conference, selects participants P and D, and confirms the desire to include each participant in the conference call, in accordance with the sequence illustrated by FIGS. 1(f) thru 1(r), respectively. Naturally, it will be appreciated that the navigation and conformation is achieved when any combination of key 130′, key 135′, key 140′ or key 145′, as well as the thumb-dial mechanism 112 are used. As shown in FIG. 2, upon set up of the conference call, all participants in the conference call are displayed on the apparatus or endpoint device 100 at each respective user's location. As a result, all of the participants are able to see who is currently participating in the conference on their respective apparatus or endpoint device 100. Naturally, it will be appreciated that H, P and D converse during the teleconference, where the exemplary screen shown in FIG. 2(a) is made available to the participants on their respective endpoint device to permit each user to select desired call conferencing options. In accordance with the exemplary embodiment, a decision is made during the conference call to add an additional participant J to the conference call, as shown in FIG. 3. Here, participant P can then add a fourth participant J to the first conference call from his endpoint, in accordance with the sequence illustrated by FIGS. 3(a) thru 3(j), respectively. One reason for P being the participant to add participant J to the conference call is based on convenience, such as because participant J is located in the contact list of participant P. FIG. 3(a) is an exemplary illustration of the display area of the apparatus or endpoint device provided to the users pursuant to the extension or addition of an additional participant to the conference call. The addition of a participant or extension of the conference call occurs when participant P, for example, engages the key 130′ to activate the add function indicated by the selection area 130 of the display 110. Upon addition of participant J to the conference call, the apparatus or endpoint device of participant H and participant D become updated to show that participant J is an additional participant in the conference call, as shown in FIG. 4, where the available functions can be displayed in the display on the apparatus or endpoint device 100 of each of the conference call participants as shown in FIG. 4(a). It should be readily understood that participant H could just as easily be the person to initiate the addition of participants to the conference call. During the conference call, participant D can split the first conference call into a pair of calls by using his endpoint device 100 when he wishes to conduct a “sidebar” conversation with participant J, as shown in FIG. 5. Here, the endpoint device 100 at the location of participant D shows that participants H and P are grouped together and that participants D and J are grouped together to indicate that a split of the first conference call between the participants has occurred, in accordance with the sequence illustrated by FIGS. 5(a) thru 5(p). In particular, FIG. 5(p) is an exemplary illustration of the display area of the apparatus or endpoint device provided to the users pursuant to the split of the conference call into multiple conference calls. Here, the screen of the apparatus or endpoint device of user D illustrates that another Conference section, i.e., Conference 2 section 125′ can be selected. It should readily be appreciated that the selection of the specific conference occurs through use of the thumb-dial mechanism 112 in a conventional manner with respect to operation of the thumb-dial mechanism itself. As shown in FIG. 6, the split of the conference call entails a first call involving participant H and participant P and a second call involving participant D and participant J. In addition, the apparatus or endpoint device 100 of all four participants will show the two conference calls with corresponding participants, where the available functions can be displayed in the display on the apparatus or endpoint device 100 of each of the conference call participants as shown in FIG. 6(a). Finally, the apparatus or endpoint device 100 of the invention makes it possible to move participant P, who is involved in the conference call with participant H, into the conference call that participant J is involved in by selecting the image of participant P shown on the apparatus or endpoint device 100 of participant J, as shown in FIG. 7. Here, the endpoint device 100 at the location of participant J shows that participant P has been moved back into the conference call involving participant J, in accordance with the sequence illustrated by FIGS. 7(a) thru 7(k). FIG. 7(k) is an exemplary illustration of the display area of the apparatus or endpoint device 100 provided to the users pursuant to moving participant P into the conference call that is created pursuant to the conference call move. With reference to the display 110 of the apparatus or endpoint device 100, participant J navigates and selects the Conference 2 section 125′ using the thumb-dial mechanism 112. The movement of participant P into her call (e.g., the second conference call) occurs without having to move participant H into this conference call, who is leaving the conference to attend a meeting, and does so, as indicated in FIG. 8. The functions available to the participant in the second conference can be displayed in the display on the apparatus or endpoint device 100 of each of the conference call participants as shown in FIG. 8(a). It should be appreciated that participant H was the original initiator of the conference call. However, it is possible for a conference call to continue even though the originator of the conference call may leave the group. Using the multi-conferencing capability of the present invention, permits the management of multiple conferences simultaneously, as well as the splitting and merging of conference calls is permitted. In addition, symmetric control at the various participating endpoints and a smooth transition of conference participants from one call to another is achieved. Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
|
H
|
H04
|
H04M
|
3
|
42
|
|||
11949131
|
US20080192594A1-20080814
|
LASER POWER CONTROL SYSTEM AND METHOD USED IN OPTICAL DISC WRITER
|
ACCEPTED
|
20080730
|
20080814
|
[]
|
G11B2010
|
["G11B2010"]
|
8218415
|
20071203
|
20120710
|
369
|
040000
|
72896.0
|
DINH
|
TAN
|
[{"inventor_name_last": "Liu", "inventor_name_first": "Chi-Yuan", "inventor_city": "Hsinchu", "inventor_state": "", "inventor_country": "TW"}]
|
A laser power control system and method used in an optical disc writer. According to a write power value, the laser power control system drives a laser to output a write power through a first channel. According to a proportional value, the laser power control system drives the laser to output an overdrive power through a second channel. By using a close loop control of the laser power control system, the write power and the overwrite power are independent of the temperature changes.
|
1. A laser power control system used in an optical disc writer, comprising: a digital-to-analog converter, for receiving a write power value and converting the write power value to an analog signal; a compensator, for generating a compensating signal according to a difference of the analog signal and a feedback signal; a laser diode; a first laser driver, for generating a first driving current according to the compensating signal, and outputting the first driving current to the laser diode to output a laser beam having a write power; a proportional element having a proportional value, for receiving the compensating signal and outputting an output signal, wherein the output signal is the compensating signal multiplied by the proportional value; a second laser driver, for generating a second driving current according to the output signal, and outputting the second driving current to the laser diode, wherein the second driving current is superposed to the first driving current, and the laser diode outputs an overdrive power according to the second driving current; and a front monitor diode, for detecting the power outputted from the laser diode, and generating the feedback signal according to the detected power. 2. The laser power control system according to claim 1, wherein the system comprises a memory for storing an adjusting curve, wherein the adjusting curve represents a ratio of the overdrive power and the write power according to different proportional values; wherein the overdrive power is determined according to the write power value, the proportional value, and the adjusting curve. 3. A laser power control method used in an optical disc writer having a firmware capable of setting a write power value and a proportional value, comprising the steps of: driving a laser diode to output a write power through a first channel according to the write power value; and driving the laser diode to output an overdrive power through a second channel according to the proportional value. 4. The laser power control method according to claim 3, the method comprises providing an adjusting curve, wherein the adjusting curve represents a ratio between the overdrive power and the write power according to different proportional values; and determining the overdrive power according to the write power value, the proportional value, and the adjusting curve.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>A write strategy of an optical disc writer, and a driving signal of a pickup head to control a laser output power are closely related to the write quality of the recorded optical disc. FIG. 1 depicts a diagram showing a write strategy of an optical disc writer in the prior art. Data formed on a spiral track of an optical disc comprises a plurality of marks (pits) and non-marks (lands). For forming a mark 10 on a track of an optical disc, a laser beam having a write power Pw is outputted from a laser diode of a pickup head, and is focused on the track of the optical disc. However, for heating the track in a relatively short time and for forming a more precise mark 10 , an overdrive power Po must be superposed to the write power Pw in an initial period of forming the mark 10 . In another word, if the overdrive power Po can be efficiently controlled to an accurate value, the jitter value of the recorded data can be reduced, so as the write quality of the recorded optical disc can be enhanced. Moreover, as depicted in FIG. 1 , the read power Pr, outputted from the laser diode of the pickup head, is for reading the marks and non-marks on the tracks of the optical disc. Before the data writing process of an optical disc writer, the write power Pw must be determined first via the optical disc writer executing an optimum power calibration in a power calibration area of the optical disc. After the write power Pw is determined, the write power Pw is maintained within a specific range via a close loop control in the optical disc writer. FIG. 2 depicts a block diagram showing the configuration of a prior-art laser power control system. Generally, the optical disc writer uses a digital write power value to control the laser diode to output a write power Pw. Initially, the digital write power value is applied to the laser power control system and converted to an analog signal via a first digital-to-analog converter DAC 111 . Then a compensator 12 generates a compensating signal according to the difference of the analog signal and a feedback signal, and outputs the compensating signal to a first laser driver LDD 1 14 . According to the compensating signal, the first laser driver LDD 1 14 generates a first driving current I 1 . The first driving current I 1 is then outputted to a laser diode LD 16 through a first channel CH 1 for driving the laser diode LD 16 to output a predefined write power Pw. For maintaining the write power Pw within a specific range, there is a front monitor diode FMD 18 to detect the laser beam outputted from the laser diode LD 16 , and then generates the feedback signal according to the power of the detected laser beam. Moreover, for making the laser diode LD 16 capable of outputting an overdrive power Po, and to be superposed to the write power Pw within a specific period, a digital overdrive power value is provided. As depicted in FIG. 2 , the digital overdrive power value is transferred to a second digital-to-analog converter DAC 2 20 , and converted to an analog signal to the second laser driver LDD 2 22 . The second laser driver LDD 2 22 then outputs a second driving current I 2 within a specific period according to the analog signal outputted from the second digital-to-analog converter DAC 2 20 . The second driving current 12 is then superposed to the laser diode LD 16 through a second channel CH 2 for driving the laser diode LD 16 to output the predefined overdrive power Po. Because the overdrive power Po is only outputted within a specific period and the period is relatively short, it is hard to maintain the overdrive power Po within a specific range via an open loop control in the optical disc writer. As depicted in FIG. 2 , the prior-art optical disc writer uses the second laser driver LDD 2 22 and the digital overdrive power value to control the second driving current I 2 via an open loop control. That means the optical disc writer superposes the second driving current I 2 to the first driving current I 1 and outputs the summation current of the second driving current I 2 and the first driving current I 1 to drive the laser diode LD 16 in the specific period of forming the marks. It is well understood that the temperature of the optical disc writer is gradually increasing during data writing process, and the laser power outputted from the laser diode is gradually decreasing if a fixed driving current is provided. Because the value of the first driving current I 1 can be increased according to the increasing temperature due to the first driving current I 1 is controlled by a close loop control, the write power Pw can be maintained within a specific range and is independent of the temperature changes. However, the overdrive power Po cannot be adjusted according to the change of the temperature due to the second driving current I 2 is controlled by an open loop control. Therefore, the overdrive power Po outputted from the laser diode will gradually decrease along with the increasing temperature. Because the overdrive power Po cannot be maintained within a specific range, there is a potential that the jitter value may be increased, the write quality may be poor, and the data writing or data reading process may be even failed.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Therefore, the object of the present invention is to control the overdrive power Po precisely, so as the write quality can be maintained. The present invention discloses a laser power control system used in an optical disc writer, comprising: a digital-to-analog converter, for receiving a write power value and converting the write power value to an analog signal; a compensator, for generating a compensating signal according to a difference of the analog signal and a feedback signal; a laser diode; a first laser driver, for generating a first driving current according to the compensating signal, and transferring the first driving current to the laser diode to output a laser beam having a write power; a proportional element having a proportional value, for receiving the compensating signal and outputting an output signal, wherein the output signal is the compensating signal multiplied by the proportional value; a second laser driver, for generating a second driving current according to the output signal, and outputting the second driving current to the laser diode, wherein the second driving current is superposed to the first driving current, and the laser diode outputs an overdrive power according to the second driving current; a front monitor diode, for detecting the power outputted from the laser diode, and generating the feedback signal according to the detected power. Moreover, the present invention discloses a laser power control method used in an optical disc writer having a firmware capable of setting a write power value and a proportional value, comprising the steps of: driving a laser diode to output a write power through a first channel according to the write power value; and driving the laser diode to output an overdrive power through a second channel according to the proportional value.
|
FIELD OF THE INVENTION The present invention relates to a laser power control system and a method used in an optical disc writer, and more particularly to a laser power control system and a method applied to an optical disc writer for controlling an overdrive power during a data writing process. BACKGROUND OF THE INVENTION A write strategy of an optical disc writer, and a driving signal of a pickup head to control a laser output power are closely related to the write quality of the recorded optical disc. FIG. 1 depicts a diagram showing a write strategy of an optical disc writer in the prior art. Data formed on a spiral track of an optical disc comprises a plurality of marks (pits) and non-marks (lands). For forming a mark 10 on a track of an optical disc, a laser beam having a write power Pw is outputted from a laser diode of a pickup head, and is focused on the track of the optical disc. However, for heating the track in a relatively short time and for forming a more precise mark 10, an overdrive power Po must be superposed to the write power Pw in an initial period of forming the mark 10. In another word, if the overdrive power Po can be efficiently controlled to an accurate value, the jitter value of the recorded data can be reduced, so as the write quality of the recorded optical disc can be enhanced. Moreover, as depicted in FIG. 1, the read power Pr, outputted from the laser diode of the pickup head, is for reading the marks and non-marks on the tracks of the optical disc. Before the data writing process of an optical disc writer, the write power Pw must be determined first via the optical disc writer executing an optimum power calibration in a power calibration area of the optical disc. After the write power Pw is determined, the write power Pw is maintained within a specific range via a close loop control in the optical disc writer. FIG. 2 depicts a block diagram showing the configuration of a prior-art laser power control system. Generally, the optical disc writer uses a digital write power value to control the laser diode to output a write power Pw. Initially, the digital write power value is applied to the laser power control system and converted to an analog signal via a first digital-to-analog converter DAC 111. Then a compensator 12 generates a compensating signal according to the difference of the analog signal and a feedback signal, and outputs the compensating signal to a first laser driver LDD1 14. According to the compensating signal, the first laser driver LDD1 14 generates a first driving current I1. The first driving current I1 is then outputted to a laser diode LD 16 through a first channel CH1 for driving the laser diode LD 16 to output a predefined write power Pw. For maintaining the write power Pw within a specific range, there is a front monitor diode FMD 18 to detect the laser beam outputted from the laser diode LD 16, and then generates the feedback signal according to the power of the detected laser beam. Moreover, for making the laser diode LD 16 capable of outputting an overdrive power Po, and to be superposed to the write power Pw within a specific period, a digital overdrive power value is provided. As depicted in FIG. 2, the digital overdrive power value is transferred to a second digital-to-analog converter DAC2 20, and converted to an analog signal to the second laser driver LDD2 22. The second laser driver LDD2 22 then outputs a second driving current I2 within a specific period according to the analog signal outputted from the second digital-to-analog converter DAC2 20. The second driving current 12 is then superposed to the laser diode LD 16 through a second channel CH2 for driving the laser diode LD 16 to output the predefined overdrive power Po. Because the overdrive power Po is only outputted within a specific period and the period is relatively short, it is hard to maintain the overdrive power Po within a specific range via an open loop control in the optical disc writer. As depicted in FIG. 2, the prior-art optical disc writer uses the second laser driver LDD2 22 and the digital overdrive power value to control the second driving current I2 via an open loop control. That means the optical disc writer superposes the second driving current I2 to the first driving current I1 and outputs the summation current of the second driving current I2 and the first driving current I1 to drive the laser diode LD 16 in the specific period of forming the marks. It is well understood that the temperature of the optical disc writer is gradually increasing during data writing process, and the laser power outputted from the laser diode is gradually decreasing if a fixed driving current is provided. Because the value of the first driving current I1 can be increased according to the increasing temperature due to the first driving current I1 is controlled by a close loop control, the write power Pw can be maintained within a specific range and is independent of the temperature changes. However, the overdrive power Po cannot be adjusted according to the change of the temperature due to the second driving current I2 is controlled by an open loop control. Therefore, the overdrive power Po outputted from the laser diode will gradually decrease along with the increasing temperature. Because the overdrive power Po cannot be maintained within a specific range, there is a potential that the jitter value may be increased, the write quality may be poor, and the data writing or data reading process may be even failed. SUMMARY OF THE INVENTION Therefore, the object of the present invention is to control the overdrive power Po precisely, so as the write quality can be maintained. The present invention discloses a laser power control system used in an optical disc writer, comprising: a digital-to-analog converter, for receiving a write power value and converting the write power value to an analog signal; a compensator, for generating a compensating signal according to a difference of the analog signal and a feedback signal; a laser diode; a first laser driver, for generating a first driving current according to the compensating signal, and transferring the first driving current to the laser diode to output a laser beam having a write power; a proportional element having a proportional value, for receiving the compensating signal and outputting an output signal, wherein the output signal is the compensating signal multiplied by the proportional value; a second laser driver, for generating a second driving current according to the output signal, and outputting the second driving current to the laser diode, wherein the second driving current is superposed to the first driving current, and the laser diode outputs an overdrive power according to the second driving current; a front monitor diode, for detecting the power outputted from the laser diode, and generating the feedback signal according to the detected power. Moreover, the present invention discloses a laser power control method used in an optical disc writer having a firmware capable of setting a write power value and a proportional value, comprising the steps of: driving a laser diode to output a write power through a first channel according to the write power value; and driving the laser diode to output an overdrive power through a second channel according to the proportional value. BRIEF DESCRIPTION OF THE DRAWINGS The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: FIG. 1 is a diagram showing a write strategy utilized by a prior-art optical disc writer. FIG. 2 is a block diagram showing the configuration of a prior-art laser power control system. FIG. 3 is a block diagram showing the configuration of a laser power control system of the present invention. FIG. 4 is a diagram showing an adjusting curve of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 3 depicts a block diagram showing the configuration of a laser power control system of the present invention. Similarly, a digital write power value is applied to the laser power control system and converted to an analog signal via a first digital-to-analog converter DAC 1 110. Then a compensator 112 generates a compensating signal according to the difference of the analog signal and a feedback signal, and outputs the compensating signal to a first laser driver LDD1 114. According to the compensating signal, the first laser driver LDD1 114 generates a first driving current I1. The first driving current I1 is then outputted to a laser diode LD 116 through a first channel CH1 for driving the laser diode LD 116 to output a predefined write power Pw. For maintaining the write power Pw within a specific range, there is a front monitor diode FMD 118 to detect the laser beam outputted from the laser diode LD 116, and then generates the feedback signal according to the power of the detected laser beam. Moreover, the present invention discloses a proportional element 220 for receiving the compensating signal, and multiplying the compensating signal by a predefined proportional value P, and then outputting the multiplied compensating signal to a second laser driver LDD2 222. The second laser driver LDD2 222 then generates a second driving current I2 according to the multiplied compensating signal. The second driving current I2 is then outputted to the laser diode LD 116 through a second channel CH2 for driving the laser diode LD 116 to output a predefined overdrive power Po. Because of the proportional value P, which is set in the proportional element 220 through a firmware of the optical disc writer, the overdrive power Po has a proportional relationship with the write power Pw. In another word, when the write power Pw is maintained within a specific range due to the value of the first driving current I1 being capable of increasing along with the increasing temperature in response to a close loop control, the overdrive power Po is also maintained within a specific range due to the proportional value P. Therefore, the problem of the overdrive power Po which is decreased along with the increasing temperature can be avoided. The better jitter value of the recorded data can be maintained, so as the write quality of the recorded optical disc can be enhanced. The above-mentioned laser power control system is capable of making the second driving current I2 to drive the laser diode LD 116 outputting a maintained overdrive power Po without decreasing the value of the second driving current I2 along with the increasing temperature. However, the overdrive power Po still may not be precisely controlled by the above-mentioned laser power control system due to the first channel CH1 and the second channel CH2 may have different gains. As depicted in FIG. 3, if the gain of the first channel CH1 and the gain of the second channel CH2 are different, the ratio of the real overdrive power Po and the real write power Pw outputted from the laser diode LD 116 will not equal to the proportional value P which is set in the proportional element 220. For precisely controlling the overdrive power Po, the present invention provides an adjusting curve, wherein the adjusting curve can be generated via a practically measuring during the manufacture procedure in the factory, and then the adjusting curve can be stored in the memory of the optical disc writer. FIG. 4 depicts the adjusting curve of the present invention. For generating of the adjusting curve, a plurality of predefined proportional values is set in the proportional element 220 via a firmware of the optical disc writer. When one of the predefined proportional values set in the proportional element 220 is selected and a predefined write power value is applied to the optical disc writer, the real overdrive power Po and the real write power Pw outputted from the laser diode can be practically measured via a power meter. So as the ratio Po/Pw corresponding to the selected proportional value is obtained. After all the predefined proportional values are selected and the ratios Po/Pw corresponding to the predefined proportional values are obtained, the adjusting curve is generated. In another word, a precise overdrive power Po can be obtained according to the write power value, the proportional value P, and the adjusting curve when a data writing process is executed in the optical disc writer. And the overdrive power Po is also independent of the temperature changes. Therefore, the better jitter value can be maintained, so as the write quality of the recorded optical disc can be maintained. While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
|
G
|
G11
|
G11B
|
20
|
10
|
|||
11822712
|
US20080041007A1-20080221
|
Laminate floor panels
|
ACCEPTED
|
20080206
|
20080221
|
[]
|
E04B502
|
["E04B502", "E04B208"]
|
8490360
|
20070709
|
20130723
|
052
|
506010
|
60361.0
|
NGUYEN
|
CHI
|
[{"inventor_name_last": "Pervan", "inventor_name_first": "Darko", "inventor_city": "Viken", "inventor_state": "", "inventor_country": "SE"}, {"inventor_name_last": "Boo", "inventor_name_first": "Christian", "inventor_city": "Kagerod", "inventor_state": "", "inventor_country": "SE"}, {"inventor_name_last": "Sjostrand", "inventor_name_first": "Mattias", "inventor_city": "Helsingborg", "inventor_state": "", "inventor_country": "SE"}]
|
Floor panels are shown with discontinuous surface layers, which are mechanically connectable to each other along one pair of adjacent edges, said floor panels comprising at least two floor elements whereof at least one of the floor elements is non rectangular.
|
1. A flooring system comprising a plurality of floor panels, wherein each floor panel comprises at least two factory connected floor elements, wherein the floor panels have a discontinuous core and surface layer, wherein the floor panels are mechanically connectable to each other along one pair of adjacent edges and, wherein at least one of the floor elements comprises adjacent edges, which are inclined with an angle of more than 90 degrees and that a first pair of adjacent edges of two floor panels is provided with a mechanical locking system, adapted to lock the panels in the horizontal and vertical direction. 2. The flooring system as claimed in claim 1, wherein said first pair of adjacent edges of said two floor panels is provided with the angling locking system and a second pair of adjacent edges of said two floor panels provided with a vertical folding locking system. 3. The flooring system as claimed in claim 1, wherein said first pair of adjacent edges of said two floor panels is provided with the horizontal snapping locking system and a second pair of adjacent edges of said two floor panels provided with a tongue and groove joint. 4. The flooring system as claimed in claim 1, wherein the floor panel comprises at least 2 pairs of adjacent edges, which are inclined with an angle of more than 90 degrees. 5. The flooring system as claimed in claim 1, wherein at least one floor element comprises a surface layer which is a printed layer. 6. The flooring system as claimed in claim 1, wherein at least one of the floor elements comprises a surface layer of laminate. 7. The flooring system as claimed in claim 1, wherein at least one of the floor elements comprises a surface layer of a thermoplastic material or wood. 8. The flooring system as claimed in claim 1, wherein at least two floor elements have a decorative groove on at least one edge and wherein at least two decorative grooves meet each other at an angle other than 90 degree. 9. The flooring system as claimed in claim 1, wherein each floor panel comprises floor elements of different sizes. 10. The flooring system as claimed in claim 1, wherein the floor elements are connected to each other with a tongue, a groove and glue. 11. The flooring system as claimed in claim 1, wherein the floor panel comprises at least three floor elements and that at least two floor elements have 6 or 8 edges. 12. The flooring system as claimed in claim 1, wherein one of the floor elements have eight edges and another four edges. 13. The flooring system as claimed in claim 1, wherein two panels, in a connected state, are prevented from sliding along each other. 14. The flooring system as claimed in claim 1, wherein the floor panel comprises at least two protrusions with straight edges, which are positioned along a straight line. 15. The flooring system as claimed in claim 1, wherein at least one of the floor elements comprises 5 to 12 edges. 16. The flooring system as claimed in claim 1, wherein at least one of the floor elements comprises 6 or 8 edges. 17. The flooring system as claimed in claim 1, wherein the surface layer comprises at least two different materials. 18. The flooring system as claimed in claim 17, wherein one of the different materials is wood. 19. The flooring system as claimed in claim 17, wherein one of the materials is a laminate layer. 20. The flooring system as claimed in claim 1, wherein the mechanical connection is a locking mechanical connection. 21. The flooring system as claimed in claim 20, wherein the locking mechanical connection is a horizontal snapping or an angling or a vertical folding locking system.
|
<SOH> BACKGROUND <EOH>Laminate flooring usually comprises rectangular floor panels with a core of a 6-12 fibreboard, a 0.2-0.8 mm thick upper decorative surface layer of laminate and a 0.1-0.6 mm thick lower balancing layer of laminate, plastic, paper or like material. A laminate surface may comprise a printed melamine impregnated paper, which is pressed with an embossed sheet. The most common core material is fibreboard with high density and good stability usually called HDF—High Density Fibreboard. Sometimes also MDF—Medium Density Fibreboard—is used as core. Traditional laminate floor panels of this type have taken a large market share mainly due to the fact that advanced printing and pressing technology has made it possible to make very natural copies of mainly wood parquet floorings. Laminate floorings look like wood, but are more durable and less expensive than wood floorings. In addition to such traditional floors, which have been installed with a tongue and groove joint and with glue, floor panels have been developed which do not require the use of glue and instead are joined mechanically by means of so called mechanical locking systems. These systems comprise locking means, which lock the panels horizontally and vertically. The mechanical locking systems are usually formed by machining of the core of the panel. Alternatively, parts of the locking system can be formed of a separate material, for instance aluminium or HDF, which is integrated with the floor panel, i.e. joined with the floor panel in connection with the manufacture thereof. The main advantages of floating floors with mechanical locking systems are that they are easy to install. They can also easily be taken up again and used once more at a different location. Definition of Some Terms By “horizontal plane” or “principal plane” is meant a plane, which extends parallel to the outer part of the surface layer. Immediately juxtaposed upper parts of two adjacent joint edges of two joined floor panels together define a “vertical plane (V)” perpendicular to the horizontal plane. By “horizontally” is meant parallel to the horizontal plane and by “vertically” parallel to the vertical plane By “locking systems” are meant co-acting connecting means, which connect the floor panels vertically and/or horizontally. By “mechanical locking system” is meant that joining can take place without glue. By a “discontinuous surface layer and core” is meant the surface layer and core of two elements connected to each other to form one panel or two panels connected to each other to form a floor and consequently the core and the surface layer of the elements and the panels respectively is discontinuous. A joint is detectable between the two element or panels at the discontinuity. Prior Art Technique and Problems thereof Printing and pressing technology have in recent years been developed further and very natural copies of stone, tiles and parquet strips have been introduced on the market. There are however a lot of designs and patterns which are not possible to produce and install with the present printing, pressing and mechanical locking technology. Most designs which contain patterns or structures where parts have to be aligned with the format of the floor panel are difficult to produce since swelling and shrinking of the printed paper and the positioning of the printing paper and the press sheet are difficult to control. Joints, which cross a specific pattern, which is design to be one unite, gives an unnatural appearance. It is known that some advanced patterns could be produced with individual rectangular small floor panels, which could be connected to floor units. Such patterns and floor panels are described in WO 03/08973. This known technology is not suitable for patterns, which aim to copy for example advanced stone and tile floors. U.S. Pat. No. 6,729,091 describes small panels with polygonal shape. These panels are very difficult and costly to produce and time consuming and difficult to install. Objects and Summary A first overall objective of embodiments of the present invention is to provide a flooring system and floor panels, with preferably mechanical locking systems, which could be installed in advanced patterns and where the pattern to a large extent is obtained by the size, shape and mechanical working of the panels and the elements and not only by printing and pressing technology. More specifically the object is to provide a flooring system and floor panels with mechanical locking system where one or several of the following advantages are obtained. The floor panel should preferably be possible to assemble mechanically to a floor surface which generally only could be obtained with small individual wood, tile or stone pieces with different sizes or non parallel edges and with panels, which are not floating but glued or nailed to the sub floor The floor panels should be easy to install in spite of the fact that the floor pattern could comprise a lot of small floor panels with different sizes and advanced shapes, which differ from the traditional rectangular panels. The substantial waste, which is usually required in order to produce floor panels and mechanical locking system in floors comprising small and non rectangular floor panels, should be reduced as much as possible The above objects of embodiments of the invention are achieved wholly or partly by a mechanical locking system and floor panels. Embodiments of the invention are evident from the description and drawings. According to the invention, a flooring system is provided comprising a plurality of floor panels with a core and a discontinuous surface layer. The floor panels are mechanically connectable to each other along one pair of adjacent edges and each floor panel comprises at least two floor elements whereof at least one of the floor elements is non rectangular. The floor elements are preferably factory connected to a floor panel and delivered as floor panels preferably in a package to the installation place as parts of a pre installed floor. The connection between floor elements should be such that several floor elements are kept in a pre determined position in relation to each other during installation. This connection could be such that floor elements are permanently connected with for instance glue or mechanical locking system, which keeps the floor elements in a correct position during installation. A floor panel, which is formed of several individual floor elements, offers a lot of advantages. Patterns could be created which are not possible to produce with printing or linear machining of the edges. Installation is easy since several floor elements could be installed at the same time. The joint between the floor elements could be rather simple and inexpensive but still strong and reliable since the floor elements are connected in the factory where suitable equipment could be used. The floor is to a large extent pre-installed at the factory and the individual elements could be connected to each other in a very efficient way. A lot of time consuming and difficult installation work where the floor installer has to work close to the floor, could be moved to a controlled factory environment.
|
<SOH> BRIEF DESCRIPTION OF THE DRAWINGS <EOH>FIGS. 1 a - 4 b illustrate known locking systems. FIGS. 4 c - 5 illustrate a first embodiment of the invention. FIGS. 6 a - 9 d illustrate embodiments of the invention. detailed-description description="Detailed Description" end="lead"?
|
The present application claims the benefit of U.S. Provisional Application No. 60/758,209, filed in the United States on Jan. 12, 2006, the entire contents of which are hereby incorporated herein by reference. TECHNICAL FIELD The invention generally relates to the field of flooring systems and laminated floor panels, which could be installed in advanced patterns, especially such floor panels which are possible to lock and unlock with mechanical locking systems. The invention concerns an improvement of the flooring system and floor panels described in WO 03/089736 Field of Application Embodiments of the present invention are particularly suitable for use in floating floors, which are not attached to the sub floor and which are formed of floor panels joined mechanically with a locking system integrated with the floor panel, i.e. mounted at the factory, are made up of one or more upper layers of printed and structured materials such as decorative laminate or decorative plastic material, an intermediate core of wood fibre based material or plastic material and preferably a lower balancing layer on the rear side of the core. The following description of known techniques, problems of known systems and objects and features of embodiments of the invention will therefore, as a non restrictive example, be aimed above all at this field of application and in particular laminate flooring. It should be emphasised that embodiments of the invention can be used in any floor panel and it could be combined with all types of known locking system, where the floor panels are intended to be joined using a mechanical locking system connecting the panels in the horizontal and vertical directions on at least two adjacent sides. The invention can thus also be applicable to, for instance, solid wooden floors, parquet floors with a core of wood or wood fibre based material and a surface of wood or wood veneer and the like, floors with a printed and preferably also varnished surface, floors with a surface layer of plastic or cork, linoleum, rubber or similar. Even floors with hard surfaces such as stone, tile and similar are included and floorings with soft wear layer, for instance needle felt glued to a board. The principle could also be used on floors which are glued or nailed to the subfloor. BACKGROUND Laminate flooring usually comprises rectangular floor panels with a core of a 6-12 fibreboard, a 0.2-0.8 mm thick upper decorative surface layer of laminate and a 0.1-0.6 mm thick lower balancing layer of laminate, plastic, paper or like material. A laminate surface may comprise a printed melamine impregnated paper, which is pressed with an embossed sheet. The most common core material is fibreboard with high density and good stability usually called HDF—High Density Fibreboard. Sometimes also MDF—Medium Density Fibreboard—is used as core. Traditional laminate floor panels of this type have taken a large market share mainly due to the fact that advanced printing and pressing technology has made it possible to make very natural copies of mainly wood parquet floorings. Laminate floorings look like wood, but are more durable and less expensive than wood floorings. In addition to such traditional floors, which have been installed with a tongue and groove joint and with glue, floor panels have been developed which do not require the use of glue and instead are joined mechanically by means of so called mechanical locking systems. These systems comprise locking means, which lock the panels horizontally and vertically. The mechanical locking systems are usually formed by machining of the core of the panel. Alternatively, parts of the locking system can be formed of a separate material, for instance aluminium or HDF, which is integrated with the floor panel, i.e. joined with the floor panel in connection with the manufacture thereof. The main advantages of floating floors with mechanical locking systems are that they are easy to install. They can also easily be taken up again and used once more at a different location. Definition of Some Terms By “horizontal plane” or “principal plane” is meant a plane, which extends parallel to the outer part of the surface layer. Immediately juxtaposed upper parts of two adjacent joint edges of two joined floor panels together define a “vertical plane (V)” perpendicular to the horizontal plane. By “horizontally” is meant parallel to the horizontal plane and by “vertically” parallel to the vertical plane By “locking systems” are meant co-acting connecting means, which connect the floor panels vertically and/or horizontally. By “mechanical locking system” is meant that joining can take place without glue. By a “discontinuous surface layer and core” is meant the surface layer and core of two elements connected to each other to form one panel or two panels connected to each other to form a floor and consequently the core and the surface layer of the elements and the panels respectively is discontinuous. A joint is detectable between the two element or panels at the discontinuity. Prior Art Technique and Problems thereof Printing and pressing technology have in recent years been developed further and very natural copies of stone, tiles and parquet strips have been introduced on the market. There are however a lot of designs and patterns which are not possible to produce and install with the present printing, pressing and mechanical locking technology. Most designs which contain patterns or structures where parts have to be aligned with the format of the floor panel are difficult to produce since swelling and shrinking of the printed paper and the positioning of the printing paper and the press sheet are difficult to control. Joints, which cross a specific pattern, which is design to be one unite, gives an unnatural appearance. It is known that some advanced patterns could be produced with individual rectangular small floor panels, which could be connected to floor units. Such patterns and floor panels are described in WO 03/08973. This known technology is not suitable for patterns, which aim to copy for example advanced stone and tile floors. U.S. Pat. No. 6,729,091 describes small panels with polygonal shape. These panels are very difficult and costly to produce and time consuming and difficult to install. Objects and Summary A first overall objective of embodiments of the present invention is to provide a flooring system and floor panels, with preferably mechanical locking systems, which could be installed in advanced patterns and where the pattern to a large extent is obtained by the size, shape and mechanical working of the panels and the elements and not only by printing and pressing technology. More specifically the object is to provide a flooring system and floor panels with mechanical locking system where one or several of the following advantages are obtained. The floor panel should preferably be possible to assemble mechanically to a floor surface which generally only could be obtained with small individual wood, tile or stone pieces with different sizes or non parallel edges and with panels, which are not floating but glued or nailed to the sub floor The floor panels should be easy to install in spite of the fact that the floor pattern could comprise a lot of small floor panels with different sizes and advanced shapes, which differ from the traditional rectangular panels. The substantial waste, which is usually required in order to produce floor panels and mechanical locking system in floors comprising small and non rectangular floor panels, should be reduced as much as possible The above objects of embodiments of the invention are achieved wholly or partly by a mechanical locking system and floor panels. Embodiments of the invention are evident from the description and drawings. According to the invention, a flooring system is provided comprising a plurality of floor panels with a core and a discontinuous surface layer. The floor panels are mechanically connectable to each other along one pair of adjacent edges and each floor panel comprises at least two floor elements whereof at least one of the floor elements is non rectangular. The floor elements are preferably factory connected to a floor panel and delivered as floor panels preferably in a package to the installation place as parts of a pre installed floor. The connection between floor elements should be such that several floor elements are kept in a pre determined position in relation to each other during installation. This connection could be such that floor elements are permanently connected with for instance glue or mechanical locking system, which keeps the floor elements in a correct position during installation. A floor panel, which is formed of several individual floor elements, offers a lot of advantages. Patterns could be created which are not possible to produce with printing or linear machining of the edges. Installation is easy since several floor elements could be installed at the same time. The joint between the floor elements could be rather simple and inexpensive but still strong and reliable since the floor elements are connected in the factory where suitable equipment could be used. The floor is to a large extent pre-installed at the factory and the individual elements could be connected to each other in a very efficient way. A lot of time consuming and difficult installation work where the floor installer has to work close to the floor, could be moved to a controlled factory environment. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1a-4b illustrate known locking systems. FIGS. 4c-5 illustrate a first embodiment of the invention. FIGS. 6a-9d illustrate embodiments of the invention. DESCRIPTION OF EMBODIMENTS OF THE INVENTION To facilitate understanding, several floor panels and locking systems in the figures are shown schematically. It should be emphasised that improved or different functions can be achieved using combinations of the preferred embodiments. Known locking systems which have one or more tongues and grooves or locking elements cooperating with locking grooves could be used to connect floor elements to a floor panel and to connect the floor panels to a floor. Angles, dimensions, rounded parts, etc. are only examples and could be adjusted within the principles of embodiments of the invention. FIGS. 1a-1c show known mechanical locking systems, which could be locked with angling and/or snapping. These locking systems have a tongue 10 and a grove 9 for vertical locking of adjacent edges parallel to the vertical plane V and a locking grove 12 and a locking element 8 for horizontal locking parallel with the horizontal plane H. The locking element could be located on a tongue 10 or a strip 6. FIGS. 2a-2c show mechanical locking systems, which could be locked by horizontal snapping. The locking elements could be made in one piece with the core as in FIG. 2c or of a separate material, hereafter referred to as two piece snap, as in FIG. 2a and 2b. These snap systems have a low snapping resistance and a high locking strength and are therefore very suitable to use in floor panels according to the invention. FIG. 3a-3c show mechanical locking systems which could be locked by a vertical folding. Such systems could have means for horizontal locking only, as in FIG. 3a, hereafter referred to as vertical hook systems or they could have a small tongue 10 made in one piece, as in FIG. 3b, hereafter referred to as vertical tongue systems. Alternative the tongue 10 could be flexible as in FIG. 3c. Such vertical folding with a tongue, which is displaceable horizontally, is very suitable to use in the floor panels according to the invention. Such systems are referred to a flex tongue systems. FIG. 4a-4b show traditional locking systems, which are locked vertically with a tongue 10 and a grove 9 and horizontally with glue 7. FIG. 4c show how a tongue and groove joint could be adjusted to be used in a factory connection of floor elements. The tongue 10 has been made smaller since special glue with controlled equipment could be used. The under lip 6 has been made slightly longer and extends beyond the upper lip 6′. This simplifies the application of glue and the under lip 6 could be formed such that it creates a vertical pre tension and keeps the floor element together until the glue cures. FIG. 5 illustrates schematically a cross section of a floor panel 2, which comprises two separate floor elements 1, 1′, which have been factory connected with a tongue and groove locking system. The floor panel 2 has a surface layer 31 and a core 30, which are discontinuous, and edges, which in this preferred embodiment could be locked with angling. The floor elements preferably have a decorative groove 40, bevel or similar on one edge. When floor elements are connected to floor panels very advance grove patterns could be obtained which are not possible to produce in a cost efficient way if they are to be made in an individual traditional floor panel. All these locking systems could be used in various combinations to connect floor elements 1, 1′ or two or several adjacent edges of floor panels. Mechanical locking systems could be adjusted to lock for example floor elements with a simple snapping which only holds the panels together until the glue cures. Preferred embodiments to lock floor elements are locking systems using glue, since the panels could easily be positioned correctly horizontally to each other in the factory. Floor elements could also be connected with tape on the rear side or glued to a underlay 16 which could be a foam, a cork layer, various types of plastic materials, wood based sheet materials or wood veneer or similar. FIG. 6a shows two non rectangular floor elements 1, 1′, which are connected to a floor element 2 as shown in FIG. 6b. The floor elements could have a surface of the same material, for example laminate, but they could also have a surface layers of different materials for example laminate-wood, plastic material-laminate, cork—wood etc. More than two different materials could be combined. The floor elements have decorative grooves 40 on three edges. An advanced floor panel with decorative groves, which in this embodiment meet each other at an angle different than 90 degree, could be produced with linear machining. FIG. 6d show how floor panels 2 could be installed in the order of A-H with combinations of angling, snapping and vertical folding. Rather simple locking systems could be used since the irregular shape of the panels could be used to prevent displacement along the length direction of the panels. FIG. 6e shows a floor with an advanced pattern according to the invention. Such a floor could be installed just as easy as traditional rectangular floor panels. It is obvious that 6, 8 or more floor elements could be connected to a floor panel. Start and end pieces with straight edges could be supplied. It is also obvious that all embodiments could be used to provide a floor where the floor panels are made of a single floor element. Practical testing shows however that a floor panel comprising four floor elements could be installed in advanced or complex patterns, e.g., different sizes of floor elements, more than four times faster than if the floor was installed with floor panels comprising only one floor element. FIG. 7a shows a floor element 1 which is used to form a floor panel 2 similar to the floor panel in FIG. 6. The floor panel 2 has 9 pairs (4a-4i and 5a -5i) of edges. The floor panel 2 comprises 6 pairs (4c-d 4d-e, 4g-h, 5b-c, 5e-f and 5f-g) of adjacent edges, which are inclined with an angle (A) of more than 90 degrees. The panels could be locked in several ways. The parallel edges (4b-5b, 4d-5d, 4f-5f,and 4h-5h could for example have a one or a two piece snap system and the other edges could have a traditional tongue and groove system. Alternatively all edges could be locked with horizontal snapping. Two pairs of adjacent edges (4b-5b and 4f-5f) could have an angling system and two pairs (4d-5d and 4h-5h) could have a flex tongue system. All other edges could have a vertical hook system or a vertical tongue system or a flex tongue system or any other system that allows vertical folding. The floor panel comprises two protrusions (P1, P2) with straight edges, which are positioned along a straight line L. Such protrusions will block mutual displacement of connected panels. The straight edges 4b, 4f of these protrusions could have a mechanical locking system, which could be locked with angling to opposite parallel edges 5b, 5f of a similar panel. The other edges could be locked with vertical folding. FIGS. 7c-7f show different embodiments according to the same principles. In FIG. 7d nine pairs of adjacent edges (4a-4i and 5a-5i) could be connected to each other and two pairs of adjacent edges (4c-5b and 4g-5f) could for example be connected with angling. In FIG. 7f eleven pairs of adjacent edges (4a-4k and 5a-5k) could be connected to each other and there are three protrusions P1, P2, P3 with three pairs of edges (4d-5a, 4g-5d and 4j-5g) which could be connected with for example angling and the other edges could be connected with for example vertical folding. All embodiments where some edges are installed with angling and some other with vertical folding allow a very simple installation with one angling action only around the outer edges (4d, 4g, 4j) which are positioned along the straight line L as shown in FIG. 7f. As an alternative all edges could be connected with flex tongue systems. As a non-restrictive example it could be mentioned that the edges preferably could have a length of 80-200 mm. These embodiments show that the invention makes it possible to connect floor element in a much simpler way and that the shape of the floor panel makes it possible to use other combinations of efficient and simple locking systems than what is possible with traditional locking technology based on individual floor element which are difficult to position and install. FIGS. 8a-8e and 9a-9d show different embodiments. The floor panels according to FIG. 8d are installed offset to each other while the floor panels in FIG. 9d are installed side by side in parallel rows. In embodiments with irregular shape, it is not possible to use the traditional angle, displace and snap method. Therefore preferable installation methods are angling only or snapping only or just a vertical displacement. Embodiments of the invention could be used to connect tile shaped panes installed on a wall or in furniture components. Although only preferred embodiments are specifically illustrated and described herein, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.
|
E
|
E04
|
E04B
|
5
|
02
|
|||
11897527
|
US20090057382A1-20090305
|
Container with modified corner
|
ACCEPTED
|
20090218
|
20090305
|
[]
|
B65D542
|
["B65D542", "B65D546"]
|
8408452
|
20070830
|
20130402
|
229
|
109000
|
97209.0
|
DEMEREE
|
CHRISTOPHER
|
[{"inventor_name_last": "Churvis", "inventor_name_first": "Michael A.", "inventor_city": "Germantown", "inventor_state": "TN", "inventor_country": "US"}]
|
A multi-sided container comprises a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls. At least one of the plurality of diagonal corner walls that is defined by at least one diagonal corner panel and at least one reinforcement flap is overlapping one another. A portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall.
|
1. A multi-sided container comprising a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls, at least one of the plurality of diagonal corner walls defined by at least one diagonal corner panel and at least one reinforcement flap overlapping one another and wherein a portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall. 2. The multi-sided container of claim 1 wherein the top wall is defined by two respective top panels integrally attached to the respective opposite side walls. 3. The multi-sided container of claim 1 wherein the multi-sided container includes eight sides defining by two opposite side walls, two opposite end walls, and four diagonal corner walls. 4. The multi-sided container of claim 1 wherein at least one of the plurality of diagonal corner walls includes four generally identical diagonal corner walls. 5. The multi-sided container of claim 1 wherein the at least one diagonal panel is oriented at an angle of from about 33 to about 38 degrees with respect to the longitudinal axis of the multi-sided container. 6. The multi-sided container of claim 1 wherein the bottom wall has four generally rounded corners that project under and beyond the bottom edge of each of four rounded corners. 7. The multi-sided container of claim 1 wherein the portion of the bottom wall is defined by one of the generally rounded corner thereof. 8. The multi-sided container of claim 1 wherein the at least one diagonal corner panel is integrally attached to the end wall. 9. The multi-sided container of claim 1 wherein the at least one reinforcement flap extends from at least one of the side walls. 10. The multi-sided container of claim 1 wherein each of the end walls are attached to the side walls via partial side wall panels. 11. The multi-sided container of claim 10 wherein the end wall panel, at least two diagonal corner panels, and the partial side wall panels are defined by at least one end piece wherein the end piece is integrally attached to the bottom wall. 12. The multi-sided container of claim 1 wherein the bottom wall, the side walls, and the top wall are integrally attached to one another to define a wrapper and the respective end walls, respective diagonal corner panels, and respective partial side wall panels are integrally attached to one another to define respective end pieces. 13. The multi-sided container of claim 1 wherein the bottom wall is detachable from the end walls. 14. The multi-sided container of claim 1 further comprising a pair of hand hole openings wherein each opening formed into each of the opposite end walls. 15. A multi-sided container comprising: a the bottom wall, side walls, and top walls all cooperate with one another to form a wrapper; at least one end wall, one diagonal corner panel, and a partial side wall panel all cooperate with one another to form one end piece wherein the one end piece and the wrapper being attached to one another to form a multi-sided container and wherein at least one diagonal corner panel and at least reinforcement flap overlapping one another and wherein a portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall. 16. A blank for making a multi-sided container having a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls, the blank comprising: a wrapper having a bottom panel and two pairs of side panels longitudinally attached to the bottom panel; and a pair of end pieces configured to be transversely attached to the wrapper to form a multi-sided container wherein when the multi-sided container constructed, a portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall. 17. A blank for making a multi-sided container having a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls, the blank comprising: a unitary piece of generally rectangularly shaped material having a plurality of first, approximately parallel, spaced apart fold lines delimiting a bottom panel, side wall panels, and top wall panels, a plurality of approximately parallel spaced apart second fold lines extending perpendicular to the first fold lines and defining a transversal edge of the bottom panel, side wall panels, and top wall panels, a plurality of flap panels joined to the transversal edges of the side wall panels and top wall panels; and two end pieces configured to be attached at least to the respective transversal edges of the bottom panel, each of the end pieces having a plurality of third, parallel, spaced apart fold lines delimiting end wall panels, diagonal corner panels, partial side wall panels. 18. The multi-sided container of claim 1 wherein each of the end walls are attached to the side walls via the at least one reinforcement flap. 19. The multi-sided container of claim 1 wherein the at least one reinforcement flap overlaps the at least one diagonal corner panel such that the at least one reinforcement flap covers a portion of width of the at least one diagonal corner panel. 20. The multi-sided container of claim 1 wherein the at least one reinforcement flap overlaps the at least one diagonal corner panel such that the at least one reinforcement flap covers an entire width of the at least one diagonal corner panel.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>Various styles of shipping containers are known in the prior art, including the so-called Bliss-style container in which a wrapper is folded around and stapled or glued to a pair of end pieces to form an enclosed container. The end pieces normally comprise flat panels that form the end walls in the container, and the wrapper forms the bottom wall, sidewalls and top wall. Flanges on opposite edges of the wrapper are folded and glued or otherwise fastened to the end wall panels to secure the wrapper and end pieces together. The flanges fastened against the end wall panels in the corners of the container serve to strengthen the container in comparison to a typical box that is folded from a single blank and has single panel thickness in the end walls and sidewalls. Compression or stacking strength of the container normally is enhanced by orienting the corrugations of the wrapper so that they extend vertically, but this sometimes results in inefficient utilization of corrugator width during manufacture of the container. Another common style of shipping container is the so-called Defor™ container made by International Paper Company. The Defor™ container typically is formed from a single blank that is folded to form double thickness end walls and/or sidewalls and therefore normally has greater strength than a Bliss-style container, although it requires more material in its manufacture. Stacking tabs normally project from the upper edges of the end walls or sidewalls and notches in the lower edges receive the stacking tabs when two or more containers are stacked on top of one another. One of the panels forming a part of the end walls or sidewalls can be folded to form a diagonal panel in each corner to lend greater stacking strength to the container. Other examples of prior art are disclosed in Assignee's prior U.S. Pat. Nos. 6,598,785; 5,752,648; 4,417,686. Some Bliss-style containers have modified corners wherein a diagonal corner panel extends across each corner to increase the stacking strength, but in these conventional modified corner Bliss-style containers there is nothing behind the angled panel except the edge of the wrapper and the wrapper flange that is secured to the end panel. Moreover, these modified corner design of the flanges on the wrapper must be relatively wide to reach past where the diagonal corner panel joins the end panel. This results in weak areas in the bottom of the container at each corner.
|
<SOH> SUMMARY OF THE INVENTION <EOH>The shipping container of the present invention has features of both the Bliss-style container and the Defor™ container, but has advantages possessed by neither of them. In one embodiment of the invention, the container is formed from three pieces, including a wrapper blank secured onto two end pieces. The end pieces are uniquely constructed so that a double wall lamination is created in each end wall and partial side panels are used in each sidewall of the assembled container, allowing very high compression levels to be achieved from the use of relatively lightweight materials. The design of the container in the present invention enables the corrugations in the wrapper blank to be oriented horizontally since compression strength is obtained primarily from the end structures, allowing efficient and optimized utilization of corrugator width during manufacture of the container. Accordingly, one aspect of the present invention relates a multi-sided container comprises a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls. At least one of the plurality of diagonal corner walls that is defined by at least one diagonal corner panel and at least one reinforcement flap is overlapping one another. A portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall. Another aspect of the present invention relates to a multi-sided container comprising a bottom wall, side walls, and top walls all cooperate with one another to form a wrapper. At least one end wall, one diagonal corner panel, and a partial side wall panel all cooperate with one another to form one end piece wherein the one end piece and the wrapper are attached to one another to form a multi-sided container. At least one diagonal corner panel and at least one reinforcement flap are overlapping one another. A portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall. One further aspect of the present invention relates to a blank for making a multi-sided container having a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls. The blank comprises a wrapper having a bottom panel and two pairs of side panels longitudinally attached to the bottom panel. A pair of end pieces is configured to be transversely attached to the wrapper to form a multi-sided container wherein when the multi-sided container is constructed, a portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall. Yet another aspect of the present invention relates to a blank for making a multi-sided container having a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls. The blank comprises a unitary piece of generally rectangularly shaped material having a plurality of first, approximately parallel, spaced apart fold lines delimiting a bottom panel, side wall panels, and top wall panels. A plurality of approximately parallel spaced apart second fold lines are extending perpendicular to the first fold lines and defining a transversal edge of the bottom panel, side wall panels, and top wall panels. A plurality of flap panels are joined to the transversal edges of the side wall panels and top wall panels. Two end pieces are configured to be attached at least to the respective transversal edges of the bottom panel, each of the end pieces having a plurality of third, parallel, spaced apart fold lines delimiting end wall panels, diagonal corner panels, and partial side wall panels.
|
FIELD OF THE INVENTION This invention relates generally to packaging, and in particular to a modified Bliss-style shipping container of simplified construction and enhanced stiffness and rigidity. BACKGROUND OF THE INVENTION Various styles of shipping containers are known in the prior art, including the so-called Bliss-style container in which a wrapper is folded around and stapled or glued to a pair of end pieces to form an enclosed container. The end pieces normally comprise flat panels that form the end walls in the container, and the wrapper forms the bottom wall, sidewalls and top wall. Flanges on opposite edges of the wrapper are folded and glued or otherwise fastened to the end wall panels to secure the wrapper and end pieces together. The flanges fastened against the end wall panels in the corners of the container serve to strengthen the container in comparison to a typical box that is folded from a single blank and has single panel thickness in the end walls and sidewalls. Compression or stacking strength of the container normally is enhanced by orienting the corrugations of the wrapper so that they extend vertically, but this sometimes results in inefficient utilization of corrugator width during manufacture of the container. Another common style of shipping container is the so-called Defor™ container made by International Paper Company. The Defor™ container typically is formed from a single blank that is folded to form double thickness end walls and/or sidewalls and therefore normally has greater strength than a Bliss-style container, although it requires more material in its manufacture. Stacking tabs normally project from the upper edges of the end walls or sidewalls and notches in the lower edges receive the stacking tabs when two or more containers are stacked on top of one another. One of the panels forming a part of the end walls or sidewalls can be folded to form a diagonal panel in each corner to lend greater stacking strength to the container. Other examples of prior art are disclosed in Assignee's prior U.S. Pat. Nos. 6,598,785; 5,752,648; 4,417,686. Some Bliss-style containers have modified corners wherein a diagonal corner panel extends across each corner to increase the stacking strength, but in these conventional modified corner Bliss-style containers there is nothing behind the angled panel except the edge of the wrapper and the wrapper flange that is secured to the end panel. Moreover, these modified corner design of the flanges on the wrapper must be relatively wide to reach past where the diagonal corner panel joins the end panel. This results in weak areas in the bottom of the container at each corner. SUMMARY OF THE INVENTION The shipping container of the present invention has features of both the Bliss-style container and the Defor™ container, but has advantages possessed by neither of them. In one embodiment of the invention, the container is formed from three pieces, including a wrapper blank secured onto two end pieces. The end pieces are uniquely constructed so that a double wall lamination is created in each end wall and partial side panels are used in each sidewall of the assembled container, allowing very high compression levels to be achieved from the use of relatively lightweight materials. The design of the container in the present invention enables the corrugations in the wrapper blank to be oriented horizontally since compression strength is obtained primarily from the end structures, allowing efficient and optimized utilization of corrugator width during manufacture of the container. Accordingly, one aspect of the present invention relates a multi-sided container comprises a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls. At least one of the plurality of diagonal corner walls that is defined by at least one diagonal corner panel and at least one reinforcement flap is overlapping one another. A portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall. Another aspect of the present invention relates to a multi-sided container comprising a bottom wall, side walls, and top walls all cooperate with one another to form a wrapper. At least one end wall, one diagonal corner panel, and a partial side wall panel all cooperate with one another to form one end piece wherein the one end piece and the wrapper are attached to one another to form a multi-sided container. At least one diagonal corner panel and at least one reinforcement flap are overlapping one another. A portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall. One further aspect of the present invention relates to a blank for making a multi-sided container having a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls. The blank comprises a wrapper having a bottom panel and two pairs of side panels longitudinally attached to the bottom panel. A pair of end pieces is configured to be transversely attached to the wrapper to form a multi-sided container wherein when the multi-sided container is constructed, a portion of the bottom wall projects under and beyond a bottom edge of the at least one diagonal corner wall. Yet another aspect of the present invention relates to a blank for making a multi-sided container having a bottom wall, a top wall, opposite side walls, opposite end walls, a longitudinal axis and a plurality of diagonal corner walls. The blank comprises a unitary piece of generally rectangularly shaped material having a plurality of first, approximately parallel, spaced apart fold lines delimiting a bottom panel, side wall panels, and top wall panels. A plurality of approximately parallel spaced apart second fold lines are extending perpendicular to the first fold lines and defining a transversal edge of the bottom panel, side wall panels, and top wall panels. A plurality of flap panels are joined to the transversal edges of the side wall panels and top wall panels. Two end pieces are configured to be attached at least to the respective transversal edges of the bottom panel, each of the end pieces having a plurality of third, parallel, spaced apart fold lines delimiting end wall panels, diagonal corner panels, and partial side wall panels. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing, as well as other objects and advantages of the invention, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein: FIG. 1 is a top perspective view of a container in accordance with a first embodiment of the invention; FIG. 2 is a plan view of a unitary blank B1 used to form the container shown in FIG. 1 in accordance with a first embodiment of the invention; FIG. 3 is similar to FIG. 2, showing the unitary blank in a partially folded position by illustrating a portion of the unitary blank formed into the end walls of the container depicted in FIG. 1; FIG. 4 is a perspective view of the fully constructed container formed from the unitary blank shown in FIG. 2 and illustrating the container in FIG. 1 in a partially open position; FIG. 5 is a top perspective view of a three pieces container in accordance with a second embodiment of the invention; FIG. 6 is a plan view of a wrapper blank that forms the bottom wall, top and side walls of the three-piece container depicted in FIG. 1; FIG. 7 is a plan view of a pair of blanks B2 that form the end pieces used to construct the three-piece container depicted in FIG. 5; FIG. 8 is a top perspective view of the end pieces located in their operative positions on the wrapper blank shown in FIG. 6, and illustraing the wrapper blank in the folding position around the end pieces; FIG. 9 is a perspective view of the fully constructed three-piece container depicted in FIG. 5 showing the wrapper blank folded and glued against the end pieces to form the bottom wall and side walls of the container; FIG. 10 is a top perspective view of a three piece container in accordance with a third embodiment of the invention; FIG. 11 is a plan view of a wrapper blank that forms the bottom wall, top and side walls of the three-piece container depicted in FIG. 10; FIG. 12 is a plan view of a pair of blanks that form the end pieces used to construct the three-piece container depicted in FIG. 10; FIG. 13 is a top perspective view of the end walls located in their operative positions on the wrapper blank shown in FIG. 11 and illustrating the wrapper blank in the folding position around the end walls; FIG. 14 is a perspective view of the fully constructed three-piece container depicted in FIG. 10 showing the wrapper blank folded and glued against the end walls to form the bottom wall and the side walls of the container; FIG. 15 is a top perspective view of a three piece container in accordance with a fourth embodiment of the invention; FIG. 16 is a plan view of a unitary blank B3 used to form the three piece container shown in FIG. 15 in accordance with a fourth embodiment of the invention; FIG. 17 is similar to FIG. 16 illustrating a portion of end pieces partially folded; FIG. 18 is similar to FIG. 17 illustrating the end panels are folded onto the end wall panels; FIG. 19 is similar to FIG. 18, showing the unitary blank B3 in a partially folded position by illustrating a portion of the unitary blank B3 formed into the end walls of the three piece container depicted in FIG. 15; and FIG. 20 is a perspective view of the fully constructed three-piece container formed from the blank B3 shown in FIG. 16 and illustrating the three-piece container in FIG. 15 in a partially opened position. DETAIL DESCRIPTION OF THE INVENTION FIG. 1 is a top perspective view of a container 10 in accordance with a first embodiment of the invention. The container 10 comprises a bottom wall 12, opposite parallel side walls 14, 16, opposite parallel end walls 18, 20 and diagonal corner panels 22, 24, 26 and 28 (FIG. 3) connecting the respective side walls 14, 16 and respective end walls 18, 20 at adjacent ends. The bottom 12′ has an advantage of having four identical rounded corners 13′ which enhances the integrity of the container 10 as will be described in greater detail hereinafter. The diagonal corner walls 22, 24, 26 and 28 extend at an angle generally ranges from about 33 to 38 degrees with respect to the longitudinal axis of the container 10. As one of ordinary skill in the art would appreciate, it is within the scope of the present invention to use other angles such as 45° to meet the requirement of the intended design of the container 10. Each of the side walls 14, 16 includes a respective pair of flaps 21a, 21b and 23a, 23b that are defined by respective fold lines 54a, 54b, 56a, 56b. The opposite width of the respective side walls 14 and 16 is such that the flaps 21a, 21b and 23a, 23b project at their opposite side edges over the diagonal corner walls 22, 24, 26 and 28, terminating the flaps at their edges proximately in the middle of the respective diagonal corner walls 22, 24, 26 and 28. Two top wall panels 34a, 34b generally defined a top wall that encloses the container 10. The top wall panel 34a is integrally attached to the side wall 14 and the top wall panel 34b is integrally attached to the side wall 16, but one of ordinary skill in the art would appreciate that it is within the scope of the present invention to use a single cover integrally attached to one of the side walls or end walls of the container. Alternatively, the top wall panels 34a, 34b may detachably cover the container 10. Two hand hole openings 36a, 36b (FIG. 3) are formed on the respective end walls 18, 20 to facilitate handling of the container 10. FIG. 2 is a plan view of a unitary blank B1 used to form the container 10 shown in FIG. 1 in accordance with a first embodiment of the invention. The blank B1 comprises a centrally located rectangular panel 12′ that forms the bottom wall 12. The rectangular panel 12′ has an advantage of having four identical rounded corners 13′ which enhances the integrity of the container 10 when the blank B1 is formed into container 10. Side wall forming panels 14′ and 16′ are foldably joined to opposite side edges of the panel 12′ by respective fold lines 38, 40. Each of the side wall panels 14′, 16′ includes two respective identical flaps 21a′, 21b′ and 23a′, 23b′ defined by respective fold lines 54a′, 54b′, and 56a′, 56b′. Top wall panels 34a′ and 34b′ are foldably joined to respective longitudinal edges of the sidewall panels 14′ and 16′, opposite of their folded connection to the panel 12′, by fold lines 42, 44. Each of the top wall panels 34a′, 34b′ includes two respective identical flaps 58a′, 58b′ and 60a′, 60b′ defined by respective fold lines 62a′, 62b′, and 64a′, 64b′. An Arrow mark 66 indicates the direction of corrugation of the blank B1. Similarly, each of the top wall panels 34a′, 34b′, as noted with respect to the rectangular panel 12′, has an advantage of having two identical rounded corners 15′ which enhances the integrity of the container 10 when the blank B1 is formed into container 10. In addition, it should be noted that flaps 58a′, 58b′ and 60a′, 60b′ do not extend the full width of the top wall panels 34a′, 34b′, but terminate short of the outer free edge thereof, defining projecting tabs 80a′ and 80b′. A pair of end pieces 46a, 46b is foldably joined to respective transverse edges of the panel 12′ by fold lines 48, 50. The end pieces 46a, 46b are essentially identical to one another and they are mirror images of one another. The end piece 46a includes an end wall panel 18′, two relatively reinforcing corner panels 22′ and 28′ foldably joined to opposite ends of the panel 18′ by fold lines 45′, 47′, and second partial sidewall panels 52a′, 52b′ are foldably joined to outer edges of respective narrow reinforcing corner panels 22′, 28′ by fold lines 55′ and 57′. Similarly, The end piece 46b includes an end wall panel 20′, two relatively reinforcing corner panels 24′ and 26′ foldably joined to opposite ends of the panel 20′ by fold lines 72′, 74′, and second partial sidewall panels 54a′, 54b′ are foldably joined to outer edges of respective corner panels 24′, 26′ by fold lines 76′ and 78′. Openings 36a′, 36b′ are formed on the respective end wall panels 18′, 20′ so that when the blank B1 is folded, these openings 36a′, 36b′ forms the hand hole openings 36a, 36b in the container 10 as described with reference to FIG. 1. FIG. 3 is similar to FIG. 2, showing the unitary blank B1 in a partially folded position by illustrating a portion of the unitary blank B1 formed into the end walls 18, 20 of the container 10 depicted in FIG. 1. Each of the end pieces 46a′ and 46b′ is folded 90 degrees with respect to their fold lines 48 and 50. Then, the respective relatively diagonal corner panels 22′, 24′ and 26′, 28′ are folded inwardly toward the bottom panel 12′ to form the diagonal corner panels 22′, 24′ and 26′, 28′ at an angle generally 38 degrees with respect to the longitudinal axis of the container 10 so that each of the rounded corners 13 provides a greater base by increasing surface area for the diagonal corner panels 22′, 24′ and 26′, 28′ to transmit pressure applied at the contact area of the diagonal corner panels and the bottom wall. Then, partial sidewall panels 52a′, 52b′, 54a′, 54b′ are folded with respect to fold lines 55′, 57′, 76′, and 78′ in a manner such that the bottom edges of the partial sidewall panels 52a′, 52b′, 54a′, 54b′ are respectively coincided with the fold line 38 and 40. FIG. 4 is a perspective view of the fully constructed container 10 formed from the blank shown in FIG. 2 and illustrating the container 10 in FIG. 1 in a partially opened position. The respective side wall forming panels 14′ and 16′ are folded at 90 degrees with respect to the panel 12′ along the fold lines 38, 40 and configured to be attached with the respective partial sidewall panels 52a, 52b and 54a, 54b so that the respective side wall forming panels 14′ and 16′ and the respective partial sidewall panel 52a, 52b and 54a, 54b are glued to one another. Next, the respective top wall panels 34a′, 34b′ are folded along respective fold lines 42, 44 to form top wall 34a, 34b as depicted in FIG. 4. The respective flaps 58a, 58b, 60a, 60b are folded along the respective fold lines 62′a, 62b′, 64a′, 64b′ and tucked inside the container 10. FIG. 5 is a top perspective view of a container 70 in accordance with a second embodiment of the invention. The container 70 comprises a bottom wall 72, opposite parallel side walls 74, 76, opposite parallel end walls 78, 80 and diagonal corner panels 82, 84, 86 and 88 (FIG. 8) connecting the respective side walls 74, 76 and respective end walls 78, 80 at adjacent ends. The diagonal corner walls 82, 84, 86 and 88 extend at an angle generally ranges from about 33 to 38 degrees with respect to the longitudinal axis of the container 70. Each of the side walls 74, 76 includes a respective pair of flaps 71a, 71b and 73a, 73b that are defined by respective fold lines 90a, 90b, 92a, 92b. The opposite width of the respective side walls 74 and 76 is such that they project at their opposite side edges 71a, 71b over the entire surface of the diagonal corner walls 82, 84, 86 and 88, terminating their edges at the respective edges of the diagonal corner walls 82, 84, 86 and 88. Two top walls 94a, 94b are generally defined as top wall that encloses the container 70. The top wall 94a is integrally attached to the side wall 74 and the top wall 94b is integrally attached to the side wall 76, but one ordinary skill in the art would appreciate that it is within the scope of the present invention to use a single cover integrally attached to one of the side walls 74, 76 or end walls 78, 80 of the container 70. Alternatively, the top walls 94a, 94b may detachably cover the container 70. Two hand hole openings 96a, 96b are formed on the respective end walls 78, 80 to facilitate handling of the container 70. FIG. 6 is a plan view of a wrapper blank 100 that forms the bottom wall panel 72, top walls 94a, 94b and side walls 74a, 76b of the three-piece container 70 depicted in FIG. 5 in accordance with the second embodiment of the invention. The wrapper blank 100 comprises a centrally located rectangular panel 72′ that forms the bottom wall 72. The rectangular panel 72′ has an advantage of having four identical rounded corners 75′ which enhances the integrity of the container 70 when the wrapper blank 100 is folded. Side wall forming panels 74′ and 76′ are foldably joined to opposite side edges of the panel 72′ by respective fold lines 102, 104. Each of the side wall panels 74′, 76′ includes two respective identical flaps 71a′, 71b′ and 73a′, 73b′ defined by respective fold lines 90a′, 90b′, and 92a′, 92b′. Top wall panels 94a′ and 94b′ are foldably joined to respective longitudinal edges of the sidewall panels 74′ and 76′, opposite of their folded connection to the panel 72′, by fold lines 110, 112. Each of the top wall panels 94a′, 94b′ includes two respective identical flaps 114a′, 114b′ and 116a′, 116b′ defined by respective fold lines 118a′, 118b′, and 120a′, 120b′. An Arrow mark 122 indicates the direction of corrugation of the wrapper blank 100. Similarly, each of the top wall panels 94a′, 94b′, as noted with respect to the rectangular panel 72′, has an advantage of having two identical rounded corners 124′ which enhances the integrity of the container 70 when the wrapper blank 100 is folded. In addition, it should be noted that flaps 114a′, 114b′ and 116a′, 116b′ do not extend the full width of the top wall panels 94a′, 94b′, but terminate short of the outer free edge thereof, defining projecting tabs 126a′ and 126b′. A pair of flaps 126a′, 126b′ is foldably joined to respective transverse edges of the panel 72′ by fold lines 128, 130. The flaps 126a′, 126b′ are essentially identical to one another and they are mirror images of one another. The respective flaps 126a′, 126b′ are glued to the respective end walls 78, 80 when the wrapper blank 100 is folded to form the bottom wall 72, side walls 74, 76, and top walls 94a and 94b. FIG. 7 is a plan view of a pair of blanks B2, blank 132a′ and blank 132b′ each form the end walls 78 and 80 used to construct the three-piece container 70 depicted in FIG. 5. The pair of end pieces 132a′ and 132b′ is attached to respective transverse edges of the panel 72′. The end pieces 132a′ and 132b′ are essentially identical to one another and they are mirror images of one another. The end piece 132a′ includes an end wall panel 78′, two relatively narrow reinforcing corner panels 82′ and 88′ foldably joined to opposite ends of the panel 78′ by fold lines 134, 136, and second partial sidewall panels 138a′, 138b′ are foldably joined to outer edges of respective narrow reinforcing corner panels 82′ and 88′ by fold lines 135 and 140. Similarly, The end piece 132b′ includes an end wall panel 80′, two relatively narrow reinforcing corner panels 84′ and 86′ foldably joined to opposite ends of the panel 80′ by fold lines 142, 144, and second partial sidewall panels 150a′, 150b′ are foldably joined to outer edges of respective narrow reinforcing corner panels 84′ and 86′ by fold lines 146 and 148. Openings 96a′, 96b′ are formed on the respective end wall panels 78′, 80′ so that when the end pieces 132a′, 132b′ are folded, these openings 96a′, 96b′ forms the hand hole openings 96a, 96b in the container 70 as described with reference to FIG. 5. FIG. 8 is a top perspective view of the end pieces 132a, 132b located in their operative positions on the wrapper blank 100 shown in FIG. 6 and illustrating the wrapper blank 100 in the folding position around the end walls pieces 132a, 132b. The end pieces 132a, 132b are folded along their respective fold lines 134, 136, 142, and 144. The respective relatively narrow reinforcing corner panels 82′, 84′ and 86′, 88′ are folded inwardly toward the bottom panel 72′ at approximately 45 degrees so that the rounded corners 75 provides a greater base by increasing surface area for the reinforcing corner panels 82′, 84′ and 86′, 88′ to transmit pressure applied at those location. Then, partial sidewall panels 138a′, 138b′, 150a′, 150b′ are folded with respect to fold lines 138, 140, 146, and 148 in a manner such that the bottom edges of the partial sidewall panels 138a′, 138b′, 150a′, 150b′ are respectively coincided with the fold line 102 and 104. FIG. 9 is a perspective view of the fully constructed three-piece container 70 depicted in FIG. 5 showing the wrapper blank 100 folded and glued against the end pieces 132a, 132b to form the bottom wall 72 and side walls 74, 76 of the container 70. The respective side wall forming panels 74 and 76 are folded at 90 degrees with respect to the panel 72′ along the fold lines 102, 104 and configured to be attached with the respective partial sidewall panels 52a, 52b and 54a, 54b so that the respective side wall forming panels 14′ and 16′ and the respective partial sidewall 138a, 138b and 150a, 150b are glued to one another. Next, the respective top wall panels 94a′, 94b′ are folded along respective fold lines 112, 110 to form top wall 94a, 94b as depicted in FIG. 4. The respective flaps 114a, 114b, 116a, 116b are folded along the respective fold lines 118a, 118b, 120a, 120b and tucked inside the container 70. Then the flaps 126a, 126b are glued to the respective end walls 78, 80. FIG. 10 is a top perspective view of a container 200 in accordance with a third embodiment of the invention. The container 200 comprises a bottom wall 202, opposite parallel side walls 204, 206, opposite parallel end walls 208, 210 and diagonal corner panels 212, 214, 216 and 218 (FIG. 13) connecting the respective side walls 204, 206 and respective end walls 208, 210 at adjacent ends. The diagonal corner walls 212, 214, 216 and 218 extend at an angle generally 38 degrees with respect to the longitudinal axis of the container 200. Each of the side walls 204, 206 includes a respective pair of flaps 211a, 211b and 213a, 213b that are defined by respective fold lines 220a, 220b, 222a, 222b. The opposite width of the respective side walls 204 and 206 is such that they project at their opposite side edges 211a, 211b over the entire surface of the diagonal corner walls 212, 214, 216 and 218, terminating their edges at the respective edges of the diagonal corner walls 212, 214, 216 and 218. Two top walls 224a, 224b are generally defined as the top wall that encloses the container 200. The top wall 224a is integrally attached to the side wall 204 and the top wall 224b is integrally attached to the side wall 206, but one ordinary skill in the art would appreciate that it is within the scope of the present invention to use a single cover integrally attached to one of the side walls 204, 206 or end walls 208, 210 of the container 200. Alternatively, the top walls 224a, 224b may detachably cover the container 200. Two hand hole openings 226 are formed on the respective end walls 208, 210 to facilitate handling of the container 200. FIG. 11 is a plan view of a wrapper blank 230 that forms the bottom wall 202, top walls 224a, 224b and side walls 204a′, 206b′, of the three-piece container 200 depicted in FIG. 10 in accordance with the third embodiment of the invention. The wrapper blank 230 comprises a centrally located rectangular panel 202′ that forms the bottom wall 202. The rectangular panel 202′ has an advantage of having four identical rounded corners 235′ which enhances the integrity of the container 200 when the wrapper blank 230 is folded. Side wall forming panels 204′ and 206′ are foldably joined to opposite side edges of the panel 202′ by respective fold lines 232, 234. Each of the side wall panels 204′, 206′ includes two respective identical flaps 211a′, 211b′ and 213a′, 213b′ defined by respective fold lines 220a′, 220b′, and 222a′, 222b′. Top wall panels 224a′ and 224b′ are foldably joined to respective longitudinal edges of the sidewall panels 204′ and 206′, opposite of their folded connection to the panel 202′, by fold lines 236, 238. Each of the top wall panels 224a′, 224b′ includes two respective identical flaps 242a′, 242b′ and 244a′, 244b′ defined by respective fold lines 246a′, 246b′, and 248a′, 248b′. An Arrow mark 249 indicates the direction of corrugation of the wrapper blank 100. Similarly, each of the top wall panels 224a′, 224b′ has an advantage of having two identical rounded corners 252′ which enhances the integrity of the container 200 when the wrapper blank 230 is folded. In addition, it should be noted that flaps 242a′, 242b′ and 244a′, 244b′ do not extend the full width of the top wall panels 224a′, 224b′, but terminate short of the outer free edge thereof, defining projecting tabs 256a′ and 256b′. A pair of flaps 258a′, 258b′ is foldably joined to respective transverse edges of the panel 202′ by fold lines 262, 264. The flaps 258a′, 258b′ are essentially identical to one another and they are mirror images of one another. The respective flaps 258a′, 258b′ are glued to the respective end walls 208, 210 when the wrapper blank 230 is folded to form the bottom wall 202, side walls 204, 206, and top walls 224a and 224b. FIG. 12 is a plan view of a pair of end pieces 250a′, 250b′ that forms the end walls 208, 210 used to construct the three-piece container 200 as depicted in FIG. 10. The pair of end pieces 250a′, 250b′ is attached to respective transverse edges of the panel 202′. The end pieces 250a′, 250b′ are essentially identical to one another and they are mirror images of one another. The end piece 250a′ includes an end wall panel 208′, two relatively narrow reinforcing corner panels 212′ and 218′ foldably joined to opposite ends of the panel 208′ by fold lines 270, 272, and second partial sidewall panels 274a′, 274b′ are foldably joined to outer edges of respective narrow reinforcing corner panels 212′ and 218′ by fold lines 276 and 278. Similarly, The end piece 250b′ includes an end wall panel 210′, two relatively narrow reinforcing corner panels 214′ and 216′ foldably joined to opposite ends of the panel 210′ by fold lines 282, 284, and second partial sidewall panels 280a′, 280b′ are foldably joined to outer edges of respective narrow reinforcing corner panels 214′ and 216′ by fold lines 286 and 290. Openings 226a′, 226b′ are formed on the respective end wall panels 208′, 210′ so that when the end pieces 250a′, 250b′ are folded, these openings 226a′, 226b′ forms the hand hole openings 226a, 226b in the container 200 as described with reference to FIG. 10. FIG. 13 is a top perspective view of the end pieces 250a, 250b located in their operative positions on the wrapper blank 230 shown in FIG. 11 and illustrating the wrapper blank 230 in the folding position around the end pieces 250a, 250b. The end pieces 250a, 250b are folded along their respective fold lines 270, 272, 282, and 284. The respective relatively narrow reinforcing corner panels 212′, 214′ and 216′, 218′ are folded inwardly toward the bottom panel 202′ at proximately 45° degrees so that the respective corner flaps 235′ glued to the respective reinforcing corner panels 212′, 214′ and 216′, 218′ to enhance the integrity of the container 200. Then, partial sidewall panels 274a′, 274b′, 280a′, 280b′ are folded with respect to fold lines 276, 278, 286, and 290 in a manner such that the bottom edges of the partial sidewall panels 274a′, 274b′, 280a′, 280b′ are respectively coincided with the fold line 232 and 234. FIG. 14 is a perspective view of the fully constructed three-piece container 200 depicted in FIG. 10 showing the wrapper blank 230 folded and glued against the end walls 208, 210 and partial side panels 274a′, 274b′, 280a′, 280b′ to form the bottom wall 202 and the side walls 204, 206 of the container 200. The respective side wall forming panels 204′ and 206′ are folded at 90 degrees with respect to the panel 202′ along the fold lines 232, 234 and configured to be attached with the respective partial sidewall panels 274a′, 274b′, 280a′, 280b′ so that the respective side wall forming panels 204′ and 206′ and the respective partial sidewall 274a, 274b, 280a, 280b are glued to one another. Next, the respective top wall panels 224a′, 224b′ are folded along respective fold lines 236, 238 to form top wall 224a, 224b as depicted in FIG. 14. The respective flaps 242a, 242b, 244a, 244b are folded along the respective fold lines 246a, 246b, 248a, 248b and tucked inside the container 200. Then the flaps 258a, 258b are glued to the respective end walls 208, 210. FIG. 15 is a top perspective view of a container 300 in accordance with a fourth embodiment of the invention. The container 300 comprises a bottom wall 302, opposite parallel side walls 304, 306, opposite parallel end walls 308, 310 and diagonal corner panels 312, 314, 316 and 318 (FIG. 19) connecting the respective side walls 304, 306 and respective end walls 308, 310 at adjacent ends. The diagonal corner walls 312, 314, 316 and 318 extend at an angle generally 38 degrees with respect to the longitudinal axis of the container 300. Each of the side walls 304, 306 includes a respective pair of flaps 321a, 321b and 323a, 323b that are defined by respective fold lines 354a′, 354b′, 356a′, 356b′. The opposite width of the respective side walls 304 and 306 is such that they project at their opposite side edges 321a, 321b over the diagonal corner walls 322, 324, 326 and 328, terminating at their edges proximately on the edge of the respective diagonal corner walls 322, 324, 326 and 328. Two top walls 334a, 334b are generally defined as top wall that encloses the container 300. The top wall 334a is integrally attached to the side wall 314 and the top wall 334b is integrally attached to the side wall 316, but one ordinary skill in the art would appreciate that it is within the scope of the present invention to use a single cover or top wall integrally attached to one of the side walls or end walls of the container. Alternatively, the top walls 334a, 334b may detachably cover the container 300. Two hand hole openings 336a, 336b are formed on the respective end walls 308, 310 to facilitate handling of the container 300. FIG. 16 is a plan view of a unitary blank B3 used to form the container 300 shown in FIG. 15 in accordance with a fourth embodiment of the invention. The blank B3 comprises a centrally located rectangular panel 302′ that forms the bottom wall 302. The rectangular panel 302′ has an advantage of having four identical rounded corners 313′ which enhances the integrity of the container 300 when the blank B3 is formed into container 300. Side wall forming panels 314′ and 316′ are foldably joined to opposite side edges of the bottom panel 302′ by respective fold lines 338, 340. Each of the side wall panels 314′, 316′ includes two respective identical flaps 321a′, 321b′ and 323a′, 323b′ defined by respective fold lines 354a′, 354b′, and 356a′, 356b′. Top wall panels 334a′ and 334b′ are foldably joined to respective longitudinal edges of the sidewall panels 314′ and 316′, opposite of their folded connection to the bottom panel 302′, by fold lines 342, 344. Each of the top wall panels 334a′, 334b′ includes two respective identical flaps 358a′, 358b′ and 360a′, 360b′ defined by respective fold lines 362a′, 362b′, and 364a′, 364b′. An Arrow mark 366 indicates the direction of corrugation of the blank B3. Similarly, each of the top wall panels 334a′, 334b′, as noted with respect to the rectangular panel 312′, has an advantage of having two identical rounded corners 315′ which enhances the integrity of the container 300 when the blank B3 is formed into container 300. In addition, it should be noted that flaps 358a′, 358b′ and 360a′, 360b′ do not extend the full width of the top wall panels 334a′, 334b′, but terminate short of the outer free edge thereof, defining projecting tabs 380a′ and 380b′. A pair of end pieces 346a, 346b is foldably joined to respective transverse edges of the panel 312′ by fold lines 348, 350. The end pieces 346a, 346b are essentially identical to one another and they are mirror images of one another. The end piece 346a includes an end wall panel 318′, four relatively narrow reinforcing corner panels 322a′, 322b′ and 328a′, 328b′ foldably joined to opposite ends of the panel 318′ by fold lines 345, 347, and second partial sidewall panels 352a′, 352a″, 352b′, 352b″ are foldably joined to outer edges of the end wall panel 318′ by fold lines 355 and 357. Respective end wall panels 319a′, 319b′ are foldably joined to the end wall panel 318′ by fold lines 317a and 317b. Respective end panels 319a′, 319b′, respective reinforcing corner panel 322b′, 328a′, and reinforcing corner panels 322b′, 328b′ are folded along respective fold lines 315a and 315b. It should be noted that respective reinforcing corner panel 322b′, 328b′ fold 180 degrees onto respective reinforcing corner panel 322a′, 328a′ which ultimately provide double wall for the reinforcing corner wall 322, 328. Likewise, respective partial sidewall panels 352a″, 352b″ fold 180 degrees onto respective partial sidewall panels 352a′, 352b′ which ultimately provide double wall for the respective partial sidewall 352a, 352b. End panels 319a′, 319b′ fold onto the end wall panel 318′ and thereby provide a stronger end wall 308 when the blank B3 is in the folded position. The substantially doubled end walls reinforces the hand hole openings 336a, 336b so that greater weight may be carried on by the container 300 without tearing the hand hole openings 336a, 336b during transportation. The end piece 346b includes an end wall panel 320′, four relatively narrow reinforcing corner panels 322c′, 322d′ and 328c′, 328d′ foldably joined to opposite ends of the panel 320′ by fold lines 345a, 347b, and second partial sidewall panels 352c′, 352c″, 352d′, 352d″ are foldably joined to outer edges of the end wall panel 320′ by fold lines 355a and 357a. Respective end panels 319c′, 319d′ are foldably joined to the end wall panel 320′ by respective fold lines 317a′, 317b′. Respective end panels 319c′, 319d′, respective reinforcing corner panel 322c′, 322d′, and reinforcing corner wall 328c′, 328d′ are folded along respective fold lines 315c′ and 315d′. It should be noted that respective reinforcing corner panel 322d′, 328d′ fold onto respective reinforcing corner panel 322c′, 322d′ which provide double wall for the reinforcing corner wall 322, 328. Likewise, respective partial sidewall panels 352a″, 352b″ fold onto respective partial sidewall panels 352a′, 352b′ which provide double wall for the respective partial sidewall 352a, 352b. End panels 319a′, 319b′ fold onto the end wall panel 320′ and thereby provide a stronger end wall 310 when the blank B3 is in the folded position. Respective FIGS. 17, 18 are similar to FIG. 16, showing end panels 319a′, 319b′, 319c′, 319d′, reinforcing corner panels 322b′, 322c′, 328b′, 328c′ and partial sidewall panels 352a″, 352b″, 352c″, 352d″ in respective partially folded position and completely folded position with respect to their fold lines so that reinforcing corner panels 322a′, 328a′, 322c′, 328d′ and the partial sidewall panels 352a′, 352b′, 352c′, 352d′ are concealed by their respective identical panels as described hereinbefore. FIG. 19 is similar to FIG. 17, showing the unitary blank B3 in a partially folded position by illustrating a portion of the unitary blank B3 formed into the end walls 308, 310 of the container 300 depicted in FIG. 15. Each of the end pieces 346a′ and 346b′ is folded 90° degrees with respect to their fold lines 348 and 350. Then, the respective relatively narrow reinforcing doubled corner panels 322, 324 and 326, 328 are folded inwardly toward the bottom panel 302′ at angles from about 33 to about 38 degrees so that each of the rounded corners 313′ provides a greater base by increasing surface area for the reinforcing corner panels 322′, 324′ and 326′, 328′ to transmit pressure applied at those location. Then, partial sidewall panels 352a′, 352b′, 354a′, 354b′ are folded with respect to fold lines 355, 357, 376, and 378 in a manner such that the bottom edges of the partial sidewall panels 352a′, 352b′, 354a′, 354b′ are respectively coincided with the fold line 338 and 340. FIG. 20 is a perspective view of the fully constructed container 10 formed from the blank B3 shown in FIG. 16 and illustrating the container 300 in FIG. 15 in a partially opened position. The respective side wall forming panels 314′ and 316′ are folded at 90 degrees with respect to the panel 302′ along the fold lines 338, 340 and configured to be attached with the respective partial sidewall panels 352a, 352b and 354a, 354b so that the respective side wall forming panels 314′ and 316′ and the respective partial sidewall 352a, 352b and 354a, 354b are glued to one another. Next, the respective top wall panels 334a′, 334b′ are folded along respective fold lines 342, 344 to form top wall 34a, 34b as depicted in FIG. 20. The respective flaps 358a, 358b, 360a, 360b are folded along the respective fold lines 362a, 362b′, 364a′, 364b′ and tucked inside the container 300. A container manufactured as above can be made with automated equipment, and when made and glued up as described, all seams and joints are sealed against the environment. It should be noted that the angles of the reinforcing diagonal corner panel for all embodiments are from about 33 to about 38 degrees which helps to stiffen the structure of the container 10 or 70 or 200 or 300 to resist both outward and inward flexing of both the end walls and sidewalls of the container. Generally, a force against the end wall inwardly, tends to cause a somewhat equal reaction outwards on the sidewall of the container. Conversely, if the product inside the container pushes outwardly against the end wall, it tends to cause a somewhat equal reaction on the sidewalls and thereby force them to flex inwardly. This aspect is important for a couple of reasons: first, If the end wall flexes inward, it will cause the side walls to flex outward, as well as affecting positive sealing during the final closure of the side flaps. These flaps need to have a somewhat perpendicular and rigid surface to seal against as the machinery accomplishes the sealing which relies on a positive resistance from the end wall. Also, if the sidewall flexes outwardly, the intended distance between the top flaps edges will be affected causing less of an overlap, or more of a gap depending on the final sealing intention. Second, if the end wall flexes outwards, it will force the sidewalls to flex inward which will cause the top flaps to overlap more than they are intended to or have less of a gap depending on the final sealing intention. Additionally, the sealing of the side flaps will be difficult due to the end wall extending outward past a 90 degree position. Therefore, by modifying the diagonal corner panel angle ranges from about 33 to about 38 degrees, it tends to make the end walls and side walls react independently of one another when forces are applied thereto. In addition, because these reactions are now separated from each other, the flexing of the end panel is limited to the normal range that one would see in a traditional square cornered box making the final sealing of the side flaps easier. While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
|
B
|
B65
|
B65D
|
5
|
42
|
|||
11998201
|
US20080130060A1-20080605
|
Facsimile machine
|
ACCEPTED
|
20080521
|
20080605
|
[]
|
H04N100
|
["H04N100"]
|
7660021
|
20071129
|
20100209
|
358
|
003280
|
79494.0
|
BAKER
|
CHARLOTTE
|
[{"inventor_name_last": "Gotou", "inventor_name_first": "Kazunori", "inventor_city": "Osaka", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Ogawa", "inventor_name_first": "Shinya", "inventor_city": "Osaka", "inventor_state": "", "inventor_country": "JP"}, {"inventor_name_last": "Nagano", "inventor_name_first": "Daisaku", "inventor_city": "Osaka", "inventor_state": "", "inventor_country": "JP"}]
|
A facsimile machine according to the present invention is capable of accurately comprehending management information of a received document such as from which source to which destination a received document on a discharge tray has been sent, when and by whom a part or the whole has been taken away, since a received document managing section 37 manages the received facsimile document based on a placement status obtained by a placement status obtaining section 27 and stored information of a reception information storing section 31. Consequently, the received facsimile document which has been sent from a source to a destination can be managed properly based on the management information.
|
1. A facsimile machine comprising: an image forming section forming an image of a document which has been received from a source via facsimile on a sheet of recording paper; a discharge section on which the received document image-formed by the image forming section is discharged; a reception information storing section storing reception information of the received document, every time a facsimile is received from the source, as associating with recording paper identification information which is stored on a non-contact memory provided on a plurality of respective sheets of the recording paper and is capable of identifying each sheet of the recording paper uniquely; a placement status obtaining section provided in the discharge section and obtaining a placement status of the received document in the discharge section by reading the recording paper identification information of the non-contact type memory; and a received document managing section managing the received facsimile document based on the placement status obtained by the placement status obtaining section and stored information of the reception information storing section. 2. The facsimile machine according to claim 1, wherein the received document managing section manages the received facsimile document, regarding that a received document specified based on the placement status has been taken away when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made. 3. The facsimile machine according to claim 1, wherein the received document managing section manages the received facsimile document, regarding that the whole of a received document included in the facsimile reception has been taken away when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when the determination of the shifting is made about the whole of the received document included in the facsimile reception specified based on the placement status. 4. The facsimile machine according to claim 1, wherein the received document managing section manages the received facsimile document, regarding that a received document included in the facsimile reception has been partly taken away when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when the determination of the shifting is made about a part of the received document among all of the received documents included in the facsimile reception specified based on the placement status. 5. The facsimile machine according to claim 1, wherein the received document managing section manages the received facsimile document, regarding that a received document specified based on the placement status is forgotten to be removed when a determination that the placement status of the received document obtained by the placement status obtaining section does not shift from presence to absence even after a predetermined time has elapsed from the time of the facsimile reception is made. 6. The facsimile machine according to claim 1, further comprising a user identification information obtaining section obtaining user identification information of an access user every time the user makes access, wherein the received document managing section manages the received facsimile document based on the placement status obtained by the placement status obtaining section, the stored information of the reception information storing section and the user identification information obtained by the user identification information obtaining section. 7. The facsimile machine according to claim 6, wherein the received document managing section manages the received facsimile document, regarding that when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made, a received document specified based on the placement status has been taken away by a user specified based on the user identification information obtained by the user identification information obtaining section upon determination of the shifting. 8. The facsimile machine according to claim 6, wherein the received document managing section manages the received facsimile document, regarding that a received document specified based on the placement status has been taken away by a user of a proper destination when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from present to absence is made and also when a determination that a user specified based on the user identification information obtained by the user identification information obtaining section upon determination of the shifting agrees with a user of destination information based on the stored information of the reception information storing section is made. 9. The facsimile machine according to claim 6, wherein the received document managing section manages the received facsimile document, regarding that a received document specified based on the placement status has been taken away by a user different from a proper destination when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when a determination that a user specified based on the user identification information obtained by the user identification information obtaining section upon determination of the shifting does not agree with a user of destination information based on the stored information of the reception information storing section is made. 10. The facsimile machine according to claim 6, wherein the received document managing section manages the received facsimile document, regarding that a received document specified based on the placement status is forgotten to be removed by a user of destination information based on the stored information of the reception information storing section when a determination that the placement status of the received document obtained by the placement status obtaining section does not shift from presence to absence even after a predetermined time has elapsed is made. 11. The facsimile machine according to claim 1, wherein the received document managing section informs both or either of an appropriate source and/or an appropriate destination of management information of the received facsimile document. 12. The facsimile machine according to claim 11, wherein the management information is informed via facsimile or e-mail. 13. The facsimile machine according to claim 6, wherein the user identification information obtaining section obtains user identification information which is stored on a non-contact type memory carried by a plurality of respective users and is capable of identifying each user uniquely via the non-contact type memory every time the user makes access. 14. The facsimile machine according to claim 6, wherein the user identification information obtaining section obtains the user identification information through a key input operation by the user or biometric information authentication (biometric authentication) of the user every time the user makes access.
|
<SOH> BACKGROUND OF THE INVENTION <EOH>1. Field of the Invention This invention relates to a facsimile machine capable of properly managing a received facsimile document which has been sent from a source to a destination. 2. Background Art There has been a demand in conventional facsimile machines that a source wants to confirm receipt of the received document the source has sent to a destination. To satisfy the demand, it is important that the received facsimile document which has been sent from the source to the destination is properly managed at the destination side. In order to satisfy the demand that the source wants to confirm receipt of the received facsimile document, Japanese Published Unexamined Patent Application No. H8-279866 describes art wherein a receipt message to the effect that document information has been received is transmitted to the source when a document sensor provided on an output tray section detects no paper within the output tray section. Japanese Published Unexamined Patent Application No. H9-69908 describes that a paper output sensor detecting whether a received document having been output on a paper output tray is placed on the paper output tray and a voice data controlling section 13 informing the source by telephonic communication that the received document has been received when the paper output sensor detects that the received document has been taken away are provided, and thus the source can reliably confirm that the received document has been received by the destination and also the destination can reliably recognize that the received document has arrived. However, a user generally takes away only a received document addressed to himself/herself, for example, in a facsimile machine shared by a plurality of users among the foregoing conventional facsimile machines. As a result, when a received document addressed to a plurality of users is mixed and piled up on a discharge section, the received document addressed to the other users is left on the discharge section as it is. In this case, receipt of the received document cannot be confirmed properly by the facsimile machines in accordance with the conventional art. Therefore, it was difficult for the conventional facsimile machines to properly manage the received facsimile document which has been sent from the source to the destination.
|
<SOH> SUMMARY OF THE INVENTION <EOH>Accordingly, it is an object of the present invention to provide a facsimile machine capable of properly managing a received facsimile document which has been sent from a source to a destination. In order to achieve the foregoing object, a facsimile machine according to the present invention includes an image forming section forming an image of a facsimile document which has been received from a source on a sheet of recording paper, a discharge section on which the received document image-formed by the image forming section is discharged, a reception information storing section storing reception information of the received document, every time a facsimile is received from the source, as associating with recording paper identification information which is stored on a non-contact type memory provided on a plurality of respective sheets of the recording paper and is capable of identifying each sheet of the recording paper uniquely, a placement status obtaining section provided in the discharge section and obtaining a placement status of the received document in the discharge section by reading the recording paper identification information of the non-contact type memory and a received document managing section managing the received facsimile document based on the placement status obtained by the placement status obtaining section and stored information of the reception information storing section. Further, the received document managing section can be configured to manage the received facsimile document regarding that a received document specified based on the placement status has been taken away when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made. Still further, the received document managing section can be configured to manage the received facsimile document regarding that the whole of a received document included in the facsimile reception has been taken away when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when the determination of the shifting is made about the whole of the received document included in the facsimile reception specified based on the placement status. Still further, the received document managing section may be configured to manage the received facsimile document regarding that a received document included in the facsimile reception has been partly taken away when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when the determination of the shifting is made about a part of the received document among the whole of the received documents included in the facsimile reception specified based on the placement status. Furthermore, the received document managing section can be configured to manage the received facsimile document regarding that a received document specified based on the placement status is forgotten to be removed when a determination that the placement status of the received document obtained by the placement status obtaining section does not shift from presence to absence even after a predetermined time has elapsed is made. On the other hand, a user identification information obtaining section obtaining user identification information of an access user every time the user makes access is further provided, and the received document managing section can be configured to manage the received facsimile document based on the placement status obtained by the placement status obtaining section, the stored information of the reception information storing section and the user identification information obtained by the user identification information obtaining section. In this case, the received document managing section can be configured to manage the received facsimile document regarding that when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made, a received document specified based on the placement status has been taken away by a user specified based on the user identification information obtained by the user identification information obtaining section upon determination of the shifting. Further, the received document managing section may be configured to manage the received facsimile document regarding that a received document specified based on the placement status has been taken away by a user of a proper destination when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when a determination that a user specified based on the user identification information obtained by the user identification information obtaining section upon determination of the shifting agrees with a user of destination information base on the stored information of the reception information storing section is made. In addition, the received document managing section may be configured to manage the received facsimile document regarding that a received document specified based on the placement status has been taken away by a user different from a proper destination when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when a user specified based on the user identification information obtained by the user identification information obtaining section upon determination of the shifting does not agree with a user of the destination information based on the stored information of the reception information storing section is made. Furthermore, the received document managing section may be configured to manage the received facsimile document regarding that a received document specified based on the placement status is forgotten to be removed by a user of the destination information based on the stored information of the reception information storing section when a determination that the placement status of the received document obtained by the placement status obtaining section does not shift from presence to absence even after a predetermined time has elapsed is made. Further, the received document managing section can be configured to inform both or either of an appropriate source and/or an appropriate destination of management information of the received facsimile document. In this case, the management information can be configured to be informed via facsimile or e-mail. Further, the user identification information obtaining section can be configured to obtain user identification information which is stored on a non-contact type memory carried by a plurality of respective users and is capable of identifying each user uniquely, via the non-contact type memory every time the user makes access. Alternatively, the user identification information obtaining section may be configured to obtain the user identification information through a key input operation by the user or biometric authentication of the user every time the user makes access.
|
BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a facsimile machine capable of properly managing a received facsimile document which has been sent from a source to a destination. 2. Background Art There has been a demand in conventional facsimile machines that a source wants to confirm receipt of the received document the source has sent to a destination. To satisfy the demand, it is important that the received facsimile document which has been sent from the source to the destination is properly managed at the destination side. In order to satisfy the demand that the source wants to confirm receipt of the received facsimile document, Japanese Published Unexamined Patent Application No. H8-279866 describes art wherein a receipt message to the effect that document information has been received is transmitted to the source when a document sensor provided on an output tray section detects no paper within the output tray section. Japanese Published Unexamined Patent Application No. H9-69908 describes that a paper output sensor detecting whether a received document having been output on a paper output tray is placed on the paper output tray and a voice data controlling section 13 informing the source by telephonic communication that the received document has been received when the paper output sensor detects that the received document has been taken away are provided, and thus the source can reliably confirm that the received document has been received by the destination and also the destination can reliably recognize that the received document has arrived. However, a user generally takes away only a received document addressed to himself/herself, for example, in a facsimile machine shared by a plurality of users among the foregoing conventional facsimile machines. As a result, when a received document addressed to a plurality of users is mixed and piled up on a discharge section, the received document addressed to the other users is left on the discharge section as it is. In this case, receipt of the received document cannot be confirmed properly by the facsimile machines in accordance with the conventional art. Therefore, it was difficult for the conventional facsimile machines to properly manage the received facsimile document which has been sent from the source to the destination. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a facsimile machine capable of properly managing a received facsimile document which has been sent from a source to a destination. In order to achieve the foregoing object, a facsimile machine according to the present invention includes an image forming section forming an image of a facsimile document which has been received from a source on a sheet of recording paper, a discharge section on which the received document image-formed by the image forming section is discharged, a reception information storing section storing reception information of the received document, every time a facsimile is received from the source, as associating with recording paper identification information which is stored on a non-contact type memory provided on a plurality of respective sheets of the recording paper and is capable of identifying each sheet of the recording paper uniquely, a placement status obtaining section provided in the discharge section and obtaining a placement status of the received document in the discharge section by reading the recording paper identification information of the non-contact type memory and a received document managing section managing the received facsimile document based on the placement status obtained by the placement status obtaining section and stored information of the reception information storing section. Further, the received document managing section can be configured to manage the received facsimile document regarding that a received document specified based on the placement status has been taken away when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made. Still further, the received document managing section can be configured to manage the received facsimile document regarding that the whole of a received document included in the facsimile reception has been taken away when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when the determination of the shifting is made about the whole of the received document included in the facsimile reception specified based on the placement status. Still further, the received document managing section may be configured to manage the received facsimile document regarding that a received document included in the facsimile reception has been partly taken away when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when the determination of the shifting is made about a part of the received document among the whole of the received documents included in the facsimile reception specified based on the placement status. Furthermore, the received document managing section can be configured to manage the received facsimile document regarding that a received document specified based on the placement status is forgotten to be removed when a determination that the placement status of the received document obtained by the placement status obtaining section does not shift from presence to absence even after a predetermined time has elapsed is made. On the other hand, a user identification information obtaining section obtaining user identification information of an access user every time the user makes access is further provided, and the received document managing section can be configured to manage the received facsimile document based on the placement status obtained by the placement status obtaining section, the stored information of the reception information storing section and the user identification information obtained by the user identification information obtaining section. In this case, the received document managing section can be configured to manage the received facsimile document regarding that when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made, a received document specified based on the placement status has been taken away by a user specified based on the user identification information obtained by the user identification information obtaining section upon determination of the shifting. Further, the received document managing section may be configured to manage the received facsimile document regarding that a received document specified based on the placement status has been taken away by a user of a proper destination when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when a determination that a user specified based on the user identification information obtained by the user identification information obtaining section upon determination of the shifting agrees with a user of destination information base on the stored information of the reception information storing section is made. In addition, the received document managing section may be configured to manage the received facsimile document regarding that a received document specified based on the placement status has been taken away by a user different from a proper destination when a determination that the placement status of the received document obtained by the placement status obtaining section shifts from presence to absence is made and also when a user specified based on the user identification information obtained by the user identification information obtaining section upon determination of the shifting does not agree with a user of the destination information based on the stored information of the reception information storing section is made. Furthermore, the received document managing section may be configured to manage the received facsimile document regarding that a received document specified based on the placement status is forgotten to be removed by a user of the destination information based on the stored information of the reception information storing section when a determination that the placement status of the received document obtained by the placement status obtaining section does not shift from presence to absence even after a predetermined time has elapsed is made. Further, the received document managing section can be configured to inform both or either of an appropriate source and/or an appropriate destination of management information of the received facsimile document. In this case, the management information can be configured to be informed via facsimile or e-mail. Further, the user identification information obtaining section can be configured to obtain user identification information which is stored on a non-contact type memory carried by a plurality of respective users and is capable of identifying each user uniquely, via the non-contact type memory every time the user makes access. Alternatively, the user identification information obtaining section may be configured to obtain the user identification information through a key input operation by the user or biometric authentication of the user every time the user makes access. OPERATION AND EFFECTS OF THE INVENTION The facsimile machine according to the present invention includes an image forming section forming an image of a document which has been received from a source via facsimile on a sheet of recording paper, a discharge section on which the received document image-formed by the image forming section is discharged, a reception information storing section storing reception information of the received document, every time a facsimile is received from the source, as associating with recording paper identification information which is stored on a non-contact type memory provided on a plurality of respective sheets of the recording paper and capable of identifying each sheet of the recording paper uniquely, a placement status obtaining section provided in the discharge section and obtaining a placement status of the received document in the discharge section by reading the recording paper identification information of the non-contact type memory and a received document managing section as will be described next. The received document managing section manages the received facsimile document based on the placement status obtained by the placement status obtaining section and stored information of the reception information storing section. Here, ‘to manage a received facsimile document’ means comprehending accurately management information of the received document such as from which source to which destination the received document on the discharge tray has been sent, when and by whom a part or the whole has been taken away, etc., based on the placement status obtained by the placement status obtaining section and stored information of the reception information storing section, and also storing, changing, deleting or updating the comprehended management information of the received document so as to be used for informing a source or destination. Therefore, according to the facsimile machine according to the present invention, a received facsimile document which has been sent from a source to a destination can be managed properly based on the management information. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an overview of a facsimile machine in accordance with an embodiment of the present invention. FIG. 2 is an explanatory diagram showing a state of an IC tag embedded in a sheet of recording paper used in the facsimile machine according to the embodiment of the present invention. FIG. 3A is an explanatory diagram exemplifying details of reception information of a received document, stored as associated with recording paper identification information. FIG. 3B is an explanatory diagram exemplifying details of page information subordinate to the reception information in FIG. 3A. FIG. 4 is an operational flowchart to store the reception information as associating with the recording paper identification information of the received document when a document image is printed out on a sheet of the recording paper. FIG. 5 is an operational flowchart to notify acknowledgement of receipt in accordance with the received document. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a facsimile machine in accordance with an embodiment of the present invention is described in detail with reference to the drawings. General Configuration of a Facsimile Machine in Accordance With an Embodiment of the Present Invention As shown in FIG. 1, various functions including a copying job, a printing job or a network transmission (mail transmission, data transmission, etc.) job other than a facsimile communication job are available in a facsimile machine 101 according to the embodiment of the present invention. The facsimile machine 101 is controlled by a facsimile controller 3 composed of a microcomputer and dedicated hardware circuitry. As input/output devices connected to the facsimile controller 3 via a bus line 4 and taking charge of the various functions, the facsimile machine 101 is provided with a paper feeding section 1, a facsimile communication section 5, a scanner section 6, an image forming section 7, an operation panel section 8, a local area network interface (LAN I/F) section 10, an informing section 11, a discharge section 13 and a communication section 15. The facsimile machine 101 is connected with a simple mail transfer protocol (SMTP) server 103 via a local area network (LAN) 12 while connected to a public network 14. The scanner section 6 includes an image irradiation lamp and a charge coupled device (CCD) sensor constituting a scanner (not shown). The image irradiation lamp irradiates a document and the CCD sensor receives its reflection, thereby reading out an image from the document and outputting image data corresponding to the read-out image to an image processing section (not shown). The image forming section 7 includes a photoconductor drum, an exposure system and a development system, all of which are not shown. The image forming section 7 prints an image on a sheet of recording paper by using image data which has been read by the scanner section 6, image data which has been transmitted from a client personal computer (PC) by the LAN 12 via the LAN I/F section 10 and image data of facsimile data which has been received from an external facsimile machine by the facsimile communication section 5. In the embodiment, the image forming section 7 prints an image of a received facsimile document which has been received by the facsimile communication section 5 on a sheet of the recording paper. The operation panel section 8 includes a display section 8a and an operation key section 8b, and is used when a user performs operations in connection with a facsimile function, a scanner function, a printer function, a copier function, etc. The display section 8a is composed of a touch panel unit combined with a touch panel and a color liquid crystal display (LCD). The display section 8a displays various operation screens and also displays operation buttons for the user to input various operation commands by touching an appropriate place. The operation key section 8b is provided with a plurality of operation keys to accept an operation input by the user. The operation key section 8a is used when the user selectively carries out a key input operation for a necessary function from among various functions such as the facsimile function, the copier function, the printer function and the scanner function, for example. More specifically, the operation key section 8a is used, for example, when the user performs a ten-key input operation to select a facsimile machine at the other end as using the facsimile function and when the user carries out an input operation for a one touch dial or a speed dial. With the use of a network interface (10/100 Base-TX), the LAN I/F section 10 controls transmission and reception of various data with respect to a user terminal such as a client PC connected via the LAN 12. When an e-mail is transmitted/received, for example, the e-mail is transmitted/received to a sender or receiver via the LAN I/F section 10 and the SMTP server 103. The informing section 11 has a function of informing both or either of an appropriate source and/or an appropriate destination of management information about the received facsimile document. The paper feeding section 1 is a section to store recording paper before printing processing, and is provided with a paper ID detecting section 1a. The paper ID detecting section 1a has a function of reading out recording paper identification information which is stored in an IC tag 43 embedded in recording paper 41 and is capable of identifying a plurality of respective sheets of the recording paper uniquely when the printing processing is carried out, as shown in FIG. 2. As the IC tag 43, a non-contact type IC memory, for example, a μ-chip registered trademark by Hitachi, Ltd. can be used suitably. The discharge section 13 includes a discharge tray for placing a received document of which printing processing has been finished, and is provided with a paper ID detecting section 13a. The paper ID detecting section 13a (corresponding to a part of ‘a placement status obtaining section’ in the present invention) is used at the time of obtaining a placement status with regard to how much of the received document of which printing processing has been finished is left on the discharge tray. The communication section (corresponding to a part of ‘a user identification information obtaining section’ in the present invention) 15 has a function of obtaining user identification information about an access user approaching the machine 101 by performing wireless communication with a memory card 16 such as an IC card carried by the user. The facsimile communication section 5 has a function of transmitting image data of a document which has been read by the scanner section 6 to a facsimile machine at the other end via the public network 14 and receiving image data which has been transmitted from a facsimile machine at the other end. The facsimile communication section 5 includes a network controlling section 21, a modulating and demodulating section 23 and an encoding/decoding section 25. The network controlling section 21 corresponds to a network control unit (NCU), and has a function of performing network control such as sending a dial signal to the public network 14. The modulating and demodulating section 23 has a function of modulating compressed/encoded image data to a voice signal and demodulating a received voice signal to image data. The encoding/decoding section 25 has a function of compressing and encoding image data of a document targeted for communication and decompressing and decoding received image data. In order to properly manage the whereabouts of the received facsimile document which has been sent from a source to a destination, the facsimile controller 3 includes a placement status obtaining section (cooperating with the paper ID detecting section 13a to serve as ‘a placement status obtaining section’ in the present invention) 27 provided in the discharge section 13 and obtaining a placement status of the received document on the discharge tray by reading out recording paper identification information (hereinafter sometimes abbreviated as ‘recording paper ID’) of the IC tag 43, a user identification information obtaining section (cooperating with the communication section 15 to serve as ‘a user identification information obtaining section’ in the present invention) 29 obtaining user identification information (hereinafter sometimes abbreviated as ‘user ID’) of an access user every time the user makes access, a reception information storing section (corresponding to 1a reception information storing section, in the present invention) 31 storing reception information of the received document, every time a facsimile is received from the source, as associating with the recording paper identification information of the non-contact type IC tag 43, a placement status determining section 33 making a determination whether the placement status of the received document obtained by the placement status obtaining section 27 shifts from presence to absence, a removal status determining section 35 making a determination whether the shifting is made with respect to the whole of the received document included in facsimile reception specified based on the relevant placement status and a received document managing section (corresponding to ‘a received document managing section’ in the present invention) 37 managing the received facsimile document based on the placement status obtained by the placement status obtaining section 27 and stored information of the reception information storing section 31. The functions taken charge of by the placement status determining section 33 and the removal status determining section 35 may be combined into the received document managing section 37. [Exemplification of Reception Information] As attributes included in reception information stored in the reception information storing section 31 and serving an important role in the present invention, a serial number, a date and time of facsimile reception, information of a source user name, information of a destination user name, a communication result, a status whether receipt acknowledgement is notified, the number of pages of the facsimile reception can be exemplified, as shown in a table of reception information records of FIG. 3A. As attributes included in page information subordinate to the reception information of the serial number ‘03’ among the reception information records in FIG. 3A, for example, a serial number for each page, a recording paper ID for each page (‘123456—001’, ‘123456—002’ and ‘123456—003’ in the embodiment), an output paper size for each page (‘A4’ size, ‘B4’ size, ‘A3’ size, etc.), resolution for each page (‘Normal’, ‘Fine’, ‘Super_Fine’, etc.), a communication result for each page, a removal date and time for each page (‘-’ in the embodiment means the page has not been taken away yet) and a removal user name for each page (‘-’ in the embodiment means the page has not been taken away yet) can be exemplified as shown in a table of page information records of FIG. 3B. The reception information is referred to, for example, when a placement status as to which and how much of the received document among received facsimile documents that have been discharged on the discharge tray is left after the printing processing is finished is obtained. This reception information can be obtained from a facsimile machine at the other end during facsimile communication by using a non-standard facilities set-up (NSS), for example. By Internet FAX, the reception information can be obtained by writing down on a header or main body of a mail message. Operations of a Facsimile Machine According to the Embodiment Of the Present Invention Now, a flow of an operation of associating reception information with recording paper ID at facsimile reception is explained according to a flowchart in FIG. 4. The facsimile communication section 5 completes facsimile reception at Step S11. At this moment, image data of a document which has been received via facsimile is stored on an image memory (not shown). At Step S13, the facsimile controller 13 starts an image forming processing on recording paper 41 for every page of an image of the received facsimile document from the source. At Step S15, the paper ID detecting section 1a of the paper feeding section 1 reads out and detects recording paper ID of the IC tag 43 embedded in the recording paper 41 at the timing that the recording paper 41 stored in the paper feeding section 1 is sent out to the image forming section 7. The paper ID detecting section 1a then transmits the detected recording paper ID of the IC tag 43 to the facsimile controller 3. Although the embodiment is explained as giving an example that the IC tag 43 embedded in the recording paper 41 is provided in advance with the recording paper ID capable of identifying a plurality of sheets of recording paper uniquely, the present invention is not limited to the example. More specifically, for example, a writing section (not shown) for writing the recording paper ID of the IC tag 43 may be configured to be provided in the paper feeding section 1 and give the recording paper ID to the IC tag 43. In response to the recording paper ID of the IC tag 43 which has been detected at Step S15, the reception information storing section 31 stores the recording paper ID of the IC tag 43 in a field of the recording paper ID among the attributes of the page information as shown in FIG. 3B at Step S17. When the image forming processing for one page is completed at Step S19, the facsimile controller 3 makes a determination at Step S21 whether there is a page which has not been printed out yet among the received facsimile documents. As a result of the determination, the facsimile controller 3 moves the flow of the operation return to Step S13 and performs the subsequent operation sequentially when a determination that there is a page which has not been printed out yet is made. On the other hand, the facsimile controller 3 terminates a series of the flow of operations when a determination that all of the pages have finished being printed out is made. By the foregoing series of operations, the recording paper ID of the IC tag 43 embedded in each sheet of the recording paper 41 is stored in the field of the recording paper ID in the table of the page information shown in FIG. 3B subordinate to the table of the reception information shown in FIG. 3A, as associated with the reception information of the facsimile reception, with respect to the recording paper 41 of each page on which the received facsimile document has been image-formed. Subsequently, in accordance with the flowchart in FIG. 5, is explained a flow of an operation in obtaining a placement status as to which and how much of the received document among received facsimile documents that have been discharged on the discharge tray is left and notifying the source of receipt acknowledgement based on the obtained placement status. At Step S31, the facsimile controller 3 determines whether there is a communication (a reception information record) in which receipt acknowledgement of the received document has not been notified yet, referring to stored information (the field of ‘reception acknowledgement’ in FIG. 3A) of the reception information storing section 31. As a result of the determination, the facsimile controller 3 moves the flow of the operation to Step S33 when a determination that there is a communication in which receipt acknowledgement of the received document has not been notified yet. On the other hand, the facsimile controller 3 terminates a series of the flow of operations when a determination that there is no communication in which receipt acknowledgement of the received document has not been notified yet. In order to obtain a placement status which and how much of the received facsimile documents that have been discharged on the discharge tray are left, the placement status obtaining section 27 makes the paper ID detecting section 13a provided in the discharge section 13 read out recording paper ID of the IC tag 43 of the received document on the discharge tray at Step S33. At Step S35, the placement status determining section 33 and the removal status determining section 35 examine a placement status as to which and how much of the received documents is left and a removal status as to when and by whom which received document has been taken away with respect to the received facsimile documents placed on the discharge tray by referring to the placement status of the received document obtained by the placement status obtaining section 27 and the field of ‘removal date and time’ shown in FIG. 3B among the page information subordinate to the reception information of the received document of which receipt acknowledgement has not been notified yet. When a determination that the placement status of the received document obtained by the placement status obtaining section 27 shifts from presence to absence is made, at Step S37, the removal status determining section 35 regards that a received document specified based on the placement status has been taken away by a user specified based on the user ID obtained by the user ID obtaining section 29 upon determination of the shifting, and presumes a removal user who has taken away the received document. The removal status determining section 35 presumes that a received document specified based on the placement status has been taken away by a user different from a proper destination when a determination that the placement status of the received document obtained by the placement status obtaining section 27 shifts from presence to absence is made and also when a determination that the user specified based on the user ID obtained by the user ID obtaining section 29 upon determination of the shifting does not agree with a user (see the field of ‘destination user name’ among the reception information shown in FIG. 3A) in destination information based on the stored information of the reception information storing section 31 is made. On the other hand, the removal status determining section 35 presumes that a received document specified based on the placement status has been taken away by a user different from a proper destination when a determination that the user specified based on the user ID obtained by the user ID obtaining section 29 does not agree with a user in the destination information based on the stored information of the reception information storing section 31 is made. That is, the removal status determining section 35 compares the field of ‘destination user name’ in the reception information as shown in FIG. 3A with the field of ‘removal user name’ in the page information as shown in FIG. 3B to make a removal user correct/incorrect determination whether the received document has been taken away by a proper destination user correctly. As regarding an access user obtained by the user identification information obtaining section 29 as the removal user having taken away the received document when the placement status of the received document obtained by the placement status obtaining section 27 shifts from presence to absence, the access user name is stored as the removal user in the field of ‘removal user name’ in the page information shown in FIG. 3B. Accordingly, the access user obtained by the user identification information obtaining section 29 at the time that the removal status of the received document shifts from presence to absence is arranged to be regarded as the removal user having taken away the received document, as referring to ‘removal date and time’ in the page information shown in FIG. 3B. At Step S39, the facsimile controller 3 determines whether all pages (‘3’ pages in the embodiment) have been taken away relative to a communication (a reception information record) in which receipt acknowledgement of the received document has not been notified yet, as referring to the stored information (the field of ‘removal date and time’ in FIG. 3B) of the reception information storing section 31. As a result of the determination, the facsimile controller 3 moves the flow of the operation return to Step S33 and performs the subsequent operation sequentially when a determination that all of the pages among the communications in which receipt acknowledgement of the received document has not been notified yet are not taken away (there are cases where all of the pages are left in their entirety and where apart of the pages is partly left. Informing modes in those cases will be described later.) is made. On the other hand, the facsimile controller 3 moves the flow of the operation to Step S41 when a determination that all of the pages have been taken away is made. The facsimile controller 3, at Step S41, informs both or either of the appropriate source and/or the appropriate destination of receipt of the received document via an appropriate means such as facsimile communication or e-mail. At this Step S41, when a determination that the placement status of the received document obtained by the placement status obtaining section 27 shifts from presence to absence is made and also when the determination of the shifting is made about all of the received document included in the facsimile reception specified based on the placement status, the whole of the received document included in the facsimile reception is considered as having been taken away, and receipt of the received document is arranged to be informed to both or either of the appropriate source and/or destination. Further, a result of the removal user correct/incorrect determination at Step S37 may be sent together with the receipt acknowledgement. In addition, in delivering the receipt acknowledgement of the received document to the source of the facsimile via an appropriate means such as facsimile communication or e-mail, a facsimile number or an e-mail address of the appropriate source may be extracted by referring to facsimile numbers and e-mail addresses registered in an address book. [Disclosure of Variations] The foregoing embodiment is explained by giving an example that a group of facsimile reception transmitted from a source is considered as a unit and for a document of the facsimile reception, when a determination that the placement status of the received document obtained by the placement status obtaining section 27 shifts from presence to absence is made and also when the determination of the shifting is made about all of the received document included in the facsimile reception specified based on the placement status, the whole of the received document included in the facsimile reception is regarded as having been taken away, and receipt of the received document is informed to both or either of the appropriate source and/or destination. However, the present invention is not limited to the example. More specifically, for a group of a received facsimile document, for example, when a determination that the placement status of the received document obtained by the placement status obtaining section 27 shifts from presence to absence is made and also when the determination of the shifting is made about a part of the received document among all of the received documents included in facsimile reception specified based on the placement status, it may be configured such that the received document included in the facsimile reception is regarded as having been partly taken away and partial receipt of the received document is informed to both or either of the appropriate source and/or destination. When a determination that the placement status of the received document obtained by the placement status obtaining section 27 does not shift from presence to absence (regardless of the whole or a part of the received document in a group of the facsimile reception) even after a predetermined time has elapsed from the moment the facsimile reception is made, it may be configured such that the received document specified based on the placement status is regarded as being forgotten to be removed and an alarm of forgetting removal of the received document is given to both or either of the appropriate source and/or destination. Further, it may be configured such that the received document specified based on the placement status is regarded as being forgotten to be removed by a user of destination information (see the field of ‘destination user name’ in the reception information shown in FIG. 3A) based on the stored information of the reception information storing section 31 and an alarm of forgetting removal of the received document is given to both or either of the appropriate source and/or destination when a determination that the placement status of the received document obtained by the placement status obtaining section 27 does not shift from presence to absence (regardless of the whole or a part of the received document in a group of the facsimile reception) even after a predetermined time has elapsed from the moment the facsimile reception is made. As a mode of informing both or either of the appropriate source and/or destination of receipt or forgetting removal of the received document, a configuration that an alarm beeping is sounded by the facsimile machine at the destination may be adopted. By reading out user ID of a memory card 16 carried by a user, the receipt or forgetting removal of the received document may be informed at the moment when the appropriate user accesses the facsimile machine. At the time of the informing, the receipt or forgetting removal of the received document may be displayed on a display screen of the display section 8a. In addition, on the occasion of the display, the receipt or forgetting removal of the received document may be displayed, for example, continuously for a predetermined time or temporarily. Although the foregoing embodiment is explained as providing an example that the user ID obtaining section 29 obtains a user ID which is stored on a memory card (non-contact type memory) 16 carried by a plurality of respective users and is capable of identifying each user uniquely via the memory card (non-contact type memory) 16 every time the user makes access, the present invention is not limited to the example. More specifically, for example, a mode may be adopted that the user ID obtaining section 29 obtains the user ID through a key input operation by the user or biometric information authentication of the user such as a fingerprint authentication every time the user makes access. A concept of ‘to inform of management information of a received facsimile document’ in the present invention includes all that when a facsimile is received, that effect is informed to an appropriate destination user via e-mail, etc., when a received facsimile document has been taken away by a proper destination user, that effect is informed to an appropriate source user via e-mail, etc., when a part or the whole of a received facsimile document is not taken away and left behind, that effect is informed to an appropriate source or destination user via e-mail, etc., when a received facsimile document has been taken away by the incorrect user, that effect is informed to an appropriate source user, a proper destination user or the user who has taken away the document by mistake via e-mail, etc. Last, there are various modes in the aforementioned present invention obviously belonging to the identity scope. Such various modes are not regarded as departing from the spirit and scope of the invention, and every modification obvious to those skilled in the art falls within the technical scope of the claims according to the present invention. Effects of the Embodiment In the facsimile machine 101 according to the embodiment of the present invention, the received document managing section 37 manages a received facsimile document based on the placement status obtained by the placement status obtaining section 27 and stored information of the reception information storing section 31. Here, ‘to manage a received facsimile document’ is a concept including all accurately comprehending management information of the received document such as from which source to which destination the received document on the discharge tray is transmitted, when and by whom a part or the whole has been taken away, based on the placement status obtained by the placement status obtaining section 27 and the stored information of the reception information storing section 31 and storing, changing, deleting or updating the comprehended management information of the received document so as to be used for informing the source or destination. Consequently, according to the facsimile machine 101 of the embodiment of the present invention, a received facsimile document which has been transmitted from a source to a destination can be managed properly based on the management information. Since the management information of the received facsimile document as to from which source to which destination the received document on the discharge tray is transmitted and when and by whom a part or the whole has been taken away is arranged to be informed to both or either of the appropriate source and/or destination, the source is able to know the management information of the received facsimile document in detail while the destination is able to know without fail an existence of the received facsimile document addressed to himself/herself.
|
H
|
H04
|
H04N
|
1
|
00
|
|||
11759462
|
US20080304799A1-20081211
|
THERMOSETTING OPTICAL WAVEGUIDE COATING
|
ACCEPTED
|
20081122
|
20081211
|
[]
|
G02B644
|
["G02B644", "C09J502"]
|
7496263
|
20070607
|
20090224
|
385
|
129000
|
87031.0
|
PETKOVSEK
|
DANIEL
|
[{"inventor_name_last": "Xie", "inventor_name_first": "Ming", "inventor_city": "Greer", "inventor_state": "SC", "inventor_country": "US"}, {"inventor_name_last": "Strickland", "inventor_name_first": "Kenneth L.", "inventor_city": "Simpsonville", "inventor_state": "SC", "inventor_country": "US"}]
|
A method for making a panel comprising the steps of providing a plurality of waveguides including an optical core layer having a first and a second surface coated with a cladding material that forms a cladding layer, positioning a thermosetting adhesive between the plurality of waveguides, wherein the thermosetting adhesive includes a thermosetting resin, and curing the thermosetting adhesive.
|
1. A method for making a panel comprising the steps of: providing a plurality of waveguides, wherein each waveguide includes an optical core layer having a first and a second surface coated with a cladding material that forms a cladding layer; positioning a thermosetting adhesive composition between the plurality of waveguides, wherein the thermosetting adhesive composition includes a thermosetting resin; and curing the thermosetting adhesive; wherein at least one of the cladding material or the thermosetting adhesive composition further includes a light absorbing material. 2. The method of claim 1 wherein the thermosetting adhesive composition is a layer coating at least one cladding layer. 3. The method of claim 1 wherein the thermosetting adhesive composition includes the light absorbing material. 4. The method of claim 1 wherein the light absorbing material includes at least one of a carbon black material, a pigment, and a dye. 5. The method of claim 1 further comprising the step of applying a first light absorbing layer to the cladding material coating the first surface of the optical core and a second light absorbing layer to the cladding material coating the second surface of the optical core. 6. The method of claim 1 wherein the thermosetting resin includes at least one of a urethane, a polyurethane, a polyester, a polyimide, an acrylic resin, an epoxy resin, a silicone, an urea-formaldehyde resin, a melamine-formaldehyde resin, a phenolic resin, a rubber, a latex, and a vinyl ester. 7. The method of claim 6 wherein the thermosetting resin is an aqueous dispersion resin. 8. The method of claim 7 wherein the resin is selected from the group consisting of a bisphenol epoxy, an urethane modified epoxy, a rubber modified epoxy and mixtures thereof. 9. The method of claim 1 wherein the thermosetting adhesive composition further includes at least one of a curing agent, an accelerator, and a promoter. 10. The method of claim 9 wherein the thermosetting adhesive composition is uncured at room temperature and cures at a temperature less than the melting point of the core layer. 11. The method of claim 10 wherein the curing agent is a compound comprising at least one of a substituted imidazole, an amine moiety and an azo moiety. 12. The method of claim 11 wherein the substituted imidazole is an alkyl substituted imidazole. 13. The method of claim 12 wherein the alkyl substituted imidazole is 2-methylimidazole or 2-ethyl-4-methylimidazole. 14. The method of claim 1 wherein the thermosetting adhesive composition has a curing temperature less than a melting temperature of the optical core layer. 15. The method of claim 1 wherein the thermosetting adhesive composition has a curing temperature less than about 100 ° C. 16. The method of claim 15 wherein the curing temperature is about 70 to about 90 ° C. 17. The method of claim 1 wherein the core layer has a first refractive index and the cladding material has a second refractive index, wherein the first refractive index is greater than the second refractive index. 18. The method of claim 17 wherein the second refractive index is selected so light rays enter the core at an acceptance angle from about ±50°to ±30°. 19. The method of claim 1 wherein the core layer includes at least one of glass, a polycarbonate, a polymethylmethacrylate, a polycyclic olefin, a polyester, a cellulose, and copolymers thereof. 20. The method of claim 1 wherein the cladding material includes a polymer or polymer mixture. 21. The method of claim 1 wherein the cladding material includes at least one of a carbonated or polycarbonated polyurethane, a polyester, a styrene acrylic copolymer, a carboxylic acid, a n-butylacrylate, a polyethylene oxide, or a polyvinyl alcohol. 22. The method of claim 17 wherein the cladding material further includes at least one of a carboxylated styrene butadiene, and a polyester. 23. A method for making a panel comprising the steps of: providing a core layer having a first and a second surface; coating the first and the second surfaces of the core layer with a cladding material to form a cladding layer; positioning a thermosetting adhesive composition between a plurality of cladding coated core layers, wherein the thermosetting adhesive composition includes a thermosetting resin; and curing the thermosetting adhesive; wherein at least one of the cladding material and the thermosetting adhesive composition further includes a light absorbing material. 24. The method of claim 23 further comprising the step of coating the cladding material that is on the first and second surfaces of the core layer with a light absorbing material to form a light absorbing layer. 25. The method of claim 23 wherein the thermosetting adhesive composition includes the light absorbing material. 26. The method of claim 23 wherein the thermosetting resin includes at least one of a urethane, a polyurethane, a polyester, a polyimide, an acrylic resin, an epoxy resin, a silicone, an urea-formaldehyde resin, a melamine-formaldehyde resin, a phenolic resin, a rubber, a latex, and a vinyl ester. 27. The method of claim 26 wherein the thermosetting resin is an aqueous dispersion resin. 28. The method of claim 27 wherein the resin is selected from the group consisting of a bisphenol epoxy, an urethane modified epoxy, a rubber modified epoxy and mixtures thereof. 29. The method of claim 28 wherein the thermosetting adhesive composition is uncured at room temperature and cures at a temperature less than the melting point of the core layer. 30. The method of claim 29 wherein the thermosetting adhesive composition further includes a curing agent selected from at least one of a substituted imidazole, an amine moiety and an azo moiety. 31. A panel comprising: a plurality of stacked waveguides including: a core having a first and a second surface, a first cladding layer applied to the first surface of the core layer; a second cladding layer applied to the second surface of the core layer; a thermosetting adhesive layer positioned between each of the stacked waveguides to adhere the stacked waveguides upon curing, the thermosetting adhesive including a thermosetting resin; and wherein the thermosetting adhesive layer is cured. 32. The panel of claim 30 wherein the waveguide further comprises: a first light absorbing layer applied to the first cladding layer; and a second light absorbing layer applied to the second cladding layer.
|
<SOH> BACKGROUND <EOH>The present application relates generally to a thermosetting adhesive used in adhering or bonding optical waveguides to form panels. Optical waveguides have been used to develop panels that may be useful as optical display screens. The panel may be used for rear projection displays, such as those taught in U.S. Pat. No. 6,457,834 and U.S. Pat. No. 6,999,665, which are incorporated by reference herein. The panel may be used for front projection displays, such as those taught in U.S. Pat. No. 6,535,674, U.S. Pat. No. 6,741,779, and U.S. Pat. No. 7,116,873, which are incorporated by reference herein. Waveguides include a transmissive core bound by cladding where the index of refraction of the cladding is less than the index of refraction for the core. Typically, waveguides may be in the form of flat ribbons stacked vertically and extending continuously in the horizontal direction along the entire panel width. Typical waveguides and the panels made from waveguides tend to degrade when exposed to extreme environmental conditions (e.g., rain, sun, extreme temperatures, pressures, and humidity or extreme changes in temperature, pressure, and humidity). Extreme environmental conditions may be experienced by panels used in airplanes (commercial or military), automobiles, or other outdoor or extreme environmental applications (i.e. movie theater screens, ATM machines screens, or televisions mounted outside). The cladding and the adhesive(s) used in typical waveguides are the likely cause of the degradation. Therefore, there is a need for an improved waveguide or optical structure incorporating a stronger adhesive so the waveguides or panel can withstand extreme environmental conditions.
|
<SOH> SUMMARY <EOH>In one embodiment, disclosed is a method for making a panel comprising the steps of providing a plurality of waveguides including an optical core layer having a first and a second surface coated with a cladding material that forms a cladding layer, positioning a thermosetting adhesive between the plurality of waveguides, wherein the thermosetting adhesive includes a thermosetting resin, and curing the thermosetting adhesive. In another embodiment, disclosed is a method for making a panel comprising the steps of providing a core layer having a first and a second surface, coating the first and the second surfaces of the core layer with a cladding material to form a cladding layer, positioning a thermosetting adhesive between a plurality of cladding coated core layers, wherein the thermosetting adhesive includes a thermosetting resin, and curing the thermosetting adhesive. In another embodiment, the disclosed panel comprises a plurality of stacked waveguides, a thermosetting adhesive layer positioned between each of the stacked waveguides to adhere the stacked waveguides upon curing, the thermosetting adhesive including a thermosetting resin, and wherein the thermosetting adhesive layer is cured. The waveguides include including a core having a first and a second surface, a first cladding layer applied to the first surface of the core layer, and a second cladding layer applied to the second surface of the core layer. Other embodiments of the disclosed optical waveguides and associated methods will become apparent from the following description, the accompanying drawings and the appended claims.
|
BACKGROUND The present application relates generally to a thermosetting adhesive used in adhering or bonding optical waveguides to form panels. Optical waveguides have been used to develop panels that may be useful as optical display screens. The panel may be used for rear projection displays, such as those taught in U.S. Pat. No. 6,457,834 and U.S. Pat. No. 6,999,665, which are incorporated by reference herein. The panel may be used for front projection displays, such as those taught in U.S. Pat. No. 6,535,674, U.S. Pat. No. 6,741,779, and U.S. Pat. No. 7,116,873, which are incorporated by reference herein. Waveguides include a transmissive core bound by cladding where the index of refraction of the cladding is less than the index of refraction for the core. Typically, waveguides may be in the form of flat ribbons stacked vertically and extending continuously in the horizontal direction along the entire panel width. Typical waveguides and the panels made from waveguides tend to degrade when exposed to extreme environmental conditions (e.g., rain, sun, extreme temperatures, pressures, and humidity or extreme changes in temperature, pressure, and humidity). Extreme environmental conditions may be experienced by panels used in airplanes (commercial or military), automobiles, or other outdoor or extreme environmental applications (i.e. movie theater screens, ATM machines screens, or televisions mounted outside). The cladding and the adhesive(s) used in typical waveguides are the likely cause of the degradation. Therefore, there is a need for an improved waveguide or optical structure incorporating a stronger adhesive so the waveguides or panel can withstand extreme environmental conditions. SUMMARY In one embodiment, disclosed is a method for making a panel comprising the steps of providing a plurality of waveguides including an optical core layer having a first and a second surface coated with a cladding material that forms a cladding layer, positioning a thermosetting adhesive between the plurality of waveguides, wherein the thermosetting adhesive includes a thermosetting resin, and curing the thermosetting adhesive. In another embodiment, disclosed is a method for making a panel comprising the steps of providing a core layer having a first and a second surface, coating the first and the second surfaces of the core layer with a cladding material to form a cladding layer, positioning a thermosetting adhesive between a plurality of cladding coated core layers, wherein the thermosetting adhesive includes a thermosetting resin, and curing the thermosetting adhesive. In another embodiment, the disclosed panel comprises a plurality of stacked waveguides, a thermosetting adhesive layer positioned between each of the stacked waveguides to adhere the stacked waveguides upon curing, the thermosetting adhesive including a thermosetting resin, and wherein the thermosetting adhesive layer is cured. The waveguides include including a core having a first and a second surface, a first cladding layer applied to the first surface of the core layer, and a second cladding layer applied to the second surface of the core layer. Other embodiments of the disclosed optical waveguides and associated methods will become apparent from the following description, the accompanying drawings and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1-3 are side elevational views, in section, of various embodiments of wave guides; FIG. 4 is a side elevational view of a panel formed from stacked waveguides like those waveguides shown in FIGS. 1-3; FIGS. 5-7 are side elevational views, in section, of various waveguides including a light absorbing layer; FIG. 8 is a side elevational view of a panel formed from stacked waveguides like those waveguides shown in FIGS. 5-7; and FIG. 9 is a side elevational view, in section, of a waveguide showing the angle of acceptance. DETAILED DESCRIPTION It is to be understood that the figures and descriptions of the present invention may have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, other elements found in a typical projection system. Those of ordinary skill in the art will recognize that other elements may be desirable and/or required in order to implement the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. It is also to be understood that the drawings included herewith only provide diagrammatic representations of the presently preferred structures of the present invention and that structures falling within the scope of the present invention may include structures different than those shown in the drawings. Reference will now be made to the drawings wherein like structures are provided with like reference designations. As used herein the term “waveguide” means a device for guiding the flow of electromagnetic waves along a desired path. Waveguides include a core material bounded by a cladding wherein the index of refraction of the cladding is less than the index of refraction of the core. The waveguide may further include a light absorbing layer and/or an adhesive to adhere a plurality of waveguides together. Within a waveguide the core material has a refractive index that is higher than the refractive index of the cladding. As used herein the term “panel” means a plurality of waveguides stacked and adhered to one another. The panel may be used for viewing images. The panel may be part of a screen used in visual projection applications. The panel may be useful in rear projection displays, such as those taught in U.S. Pat. No. 6,457,834 and U.S. Pat. No. 6,999,665. The panel may be useful in front projection displays, such as those taught in U.S. Pat. No. 6,535,674, U.S. Pat. No. 6,741,779, and U.S. Pat. No. 7,116,873. The various compositions or materials within each of the layers of the various waveguides in the Figures described below will be described in further detail under the headings: The Core, The Cladding, and The Adhesive Layer. FIG. 1 shows an embodiment of waveguides, generally designated 11. Waveguides 11 include an optical core 12 having a first surface 14 and a second surface 16, a first cladding layer 18A applied to the first surface 14, and a second cladding layer 18B applied to the second surface 16 of core 12. The core may be provided or prepared and may be a sheet of material with a selected refractive index for the chosen panel parameters. One important parameter is the acceptance angle desired for light entering the panel. The core may have a thickness of 10 mil, 20 mil, or any other thickness that will work in the manufacturing process and result in a panel with the desired acceptance angle and other screen characteristics. In the embodiment shown in FIG. 1 an adhesive layer 20 is separate from waveguides 11 and may be inserted between the waveguides 11 to bond the waveguides 11 together to form a plurality of stacked waveguides. In another embodiment, as shown in FIG. 2, waveguides 13 may have adhesive layer 20 applied to the first cladding layer 18A. In another embodiment, adhesive 20 may be applied to the second cladding layer 18B. FIG. 3 shows another embodiment of waveguides, generally designated 15. Waveguides 15 include a core 12 bound by cladding layers 18A and 18B, which each have a layer of thermosetting adhesive 20 applied thereto. Adhesive layer 20 is shown of equal thickness on each cladding layer of both waveguides. In another embodiment, adhesive layer 20 may be of different thicknesses. A plurality of the waveguides 11, 13, and/or 15 from any of the embodiments in FIGS. 1-3 may be stacked together and adhered by the thermosetting adhesive layer(s) 20 to form a panel 30, as shown in FIG. 4. Panel 30 may be of any size and any number of waveguides. The thermosetting adhesive layer(s) 20 bond adjacent waveguides together in forming the panel. Panel 30 includes a plurality of the following layers: an adhesive layer 20, a first cladding layer 18A, a core 12, and a second cladding layer 18B. Those skilled in the art will appreciate that a typical panel is not limited to the portion shown in FIG. 4, but may include many more layers stacked and adhered together. FIG. 5 shows another embodiment of waveguides, generally designated 41. Waveguides 41 include an optical core 12 having a first surface 14 and a second surface 16, a first cladding layer 18A applied to the first surface 14, a second cladding layer 18B applied to the second surface 16, a first light absorbing composition 19A applied to the first cladding layer 18A, and a second light absorbing layer 19B applied to the second cladding layer 18B. An adhesive layer 20 is separate from waveguides 41 and may be inserted between the waveguides 41 to bond the waveguides 41 together to form a portion of panel 50, as shown in FIG. 8. As shown in FIG. 6, waveguides 43 include a core 12 having a first surface 14 and a second surface 16, a first cladding layer 18A applied to the first surface 14, a second cladding layer 18B applied to the second surface 16, a first light absorbing composition 19A applied to the first cladding layer 18A, a second light absorbing layer 19B applied to the second cladding layer 18B, and a first adhesive layer 20 applied to the first light absorbing layer 19A. Adhesive layer 20 may be of a selected thickness to bond the waveguides 43 together to form panel 50. In another embodiment, adhesive layer 20 may instead be applied to a second light absorbing layer 19B. FIG. 7 shows another embodiment of waveguides, generally designated 45. Waveguides 45 includes a first adhesive layer 20 applied to the first light absorbing layer 19A and a second adhesive layer 20 applied to the second light absorbing layer 19B. Adhesive layer 20 is shown of equal thickness on each cladding layer of both waveguides. In another embodiment, adhesive layer 20 may be of varying thickness, so long as the thickness of the adhesive once the waveguides 45 are bonded together result in the selected thickness. A plurality of the waveguides 41, 43, and/or 45 from any of the embodiments in FIGS. 5-7 may be stacked together and adhered by the thermosetting adhesive layer(s) 20 to form a panel 50, as shown in FIG. 8. Panel 50 may be of any size and any number of waveguides. The thermosetting adhesive layer(s) 20 bond adjacent waveguides together in forming the panel. Panel 30 includes a plurality of the following layers: an adhesive layer 20, a first light absorbing layer 19A, a first cladding layer 18A, a core 12, and a second cladding layer 18B, and a second light absorbing layer 19B. Those skilled in the art will appreciate that a typical panel is not limited to the portion shown in FIG. 8, but may include many more layers stacked and adhered together. In another embodiment, panels made of stacked waveguides, like panels 30 and 50, may include a light directing film that is used to turn light rays arriving in a shallow entrance angle into core 12. In another embodiment, the panel may include a light shaping film on the viewing side of the panel, separately or in combination with the light directing film, to spread light in a horizontal and vertical viewing direction as the light exits the panel. The panel may include any other features to improve the transmission of light rays along the length of the waveguides. In simple terms, the behavior of light entering the core material in a waveguide is fundamentally controlled by the property of the core, cladding, and medium surrounding the waveguide. Referring to FIG. 9, the core has a refractive index no and the cladding has a refractive index nc. A light ray entering core 12 is either refracted into the cladding 18A, 18B and attenuated (absorbed), or it is totally internally reflected at the core/cladding boundary. Total internal reflection is the reflection of the total amount of incident light at the boundary between the core and cladding. In this manner light travels within core 12 along the length of the waveguide. The maximum angle at which the light ray may enter core 12 and travel by total internal reflection within the core is termed the acceptance angle A. The value of the acceptance angle depends mainly on the properties of the selected core and cladding. The acceptance angle A, half the angle of the light acceptance cone 32, is measured between the incident ray and the normal line N to the interface of core 12, as shown in FIG. 9. The acceptance angle is often labeled theta θ. The angle range for the acceptance angle is understood by the relationship sin θ≦(no2−nc2)1/2 (assuming incoming ray is traveling through air with a refractive index of 1). When the acceptance angle is above the normal line N it is considered to be a positive acceptance angle A+and when the acceptance angle is below the normal line N it is considered to be a negative acceptance angle A−. The larger the difference in refractive index between core 12 and the cladding 18A, 18B, the larger the acceptance angle may be for light rays entering core 12 to be totally internally reflected. The first and second cladding layers 18A, 18B may have the same refractive index. The refractive index of cladding layers 18A, 18B is less than the refractive index of core 12A. The refractive index of a material is the ratio of the velocity of propagation of an electromagnetic wave in vacuum to its velocity in the material. The refractive index (n) of a material is defined as follows: n=Vv/V wherein Vv is the velocity of light in a vacuum and V is the velocity of light in the material. In general light slows down when it enters a material. Therefore, the refractive index of a material will always be greater than 1. Most materials have refractive indices between 1.32 and 2.40. Some typical refractive indexes (RI) of various materials are about: TABLE 1 MATERIAL RI Chlorotrifluoro-Ethylene (CTFE) 1.42 Cellulose Propionate 1.46 Cellulose Acetate Butyrate 1.46-1.49 Cellulose Acetate 1.46-1.50 Methylpentene Polymer 1.485 Ethyl Cellulose 1.47 Acetal Homopolymer 1.48 Acrylics 1.49 Cellulose Nitrate 1.49-1.51 Polypropylene (Unmodified) 1.49 Polyallomer 1.492 Polybutylene 1.50 Ionomers 1.51 Polyethylene (Low Density) 1.51 Nylons (PA) Type II 1.52 Acrylics Multipolymer 1.52 Polyethylene (Medium Density) 1.52 Styrene Butadiene Thermoplastic 1.52-1.55 PVC (Rigid) 1.52-1.55 Nylons (Polyamide) Type 6/6 1.53 Urea Formaldehyde 1.54-1.58 Polyethylene (High Density) 1.54 Styrene Acrylonitrile Copolymer 1.56-1.57 Polystyrene 1.57-1.60 Polycarbornate (Unfilled) 1.586 Polystyrene 1.59 As can be noted from this information many polymers that might be used in waveguides have refractive indexes that are fairly close together. As the difference in refractive index between core 12 and the first and second cladding layers 18A, 18B becomes larger, the greater the acceptance angle of light entering the optical structure, waveguide, or panel. That is, light entering at angles within the range of the acceptance angle can be totally internally reflected without being absorbed. When the refractive index difference between core 12 and the first and second cladding layers 18A, 18B becomes smaller, some of the light may be transmitted into the cladding layers instead of traveling through the core. This becomes important in the selection of compatible materials. In order to make an optical structure, waveguide, or panel useful for projection or other applications, the core 12 and cladding material 18A, 18B must adhere to each other, have an optimal difference in refractive index, and create the selected range of acceptance angle. Such selection is difficult. The Core The optical core may be any optical grade material deemed suitable for waveguides. For example, the optical core may include one or more of the following: polycarbonates, polymethylmethacrylates (PMMA), glass, polyesters, cellulose, cyclic olefins and/or copolymers thereof, or other suitable optical grade materials. The optical core may be one of the materials listed in Table 1 above or combinations thereof. Examples of the polyester cores include polyethylene terephthalate, polyethylene naphthalate or a combination thereof. Cores are selected that have excellent optical properties and will transmit light with minimal distortion or absorption of light. To provide good viewing characteristics, the optical core may have a percent transmission of between about 80 to about 100%. Transmissions less than 80% may absorb or scatter more light, thereby reducing the overall brightness of the resulting waveguide. In one embodiment the selected optical core may have a refractive index between about 1.4 to about 1.6. A polycarbonate core may have a refractive index of about 1.58. A PMMA core may have a refractive index of about 1.48. A cellulose core may have a refractive index of about 1.54. A polyethylene terephthalate core may have a refractive index of about 1.57. At this point, those skilled in the art will appreciate that any known or available optical material or combinations of optical materials may be used to form the core without departing from the scope of the present disclosure. The Cladding The cladding material may be any polymer, polymer mixture, organic material, inorganic material, or mixtures or combinations thereof that has an index of refraction that is lower than the index of refraction of the optical core and will result in a waveguide with the desired acceptance angle range. In one embodiment, the cladding may include any other ingredient or chemical substance that will make the cladding have the necessary properties for use in a waveguide or panel. In one embodiment, the cladding may be selected from the group consisting of a polyurethane, epoxy, carboxylated acrylic, acrylic styrene polymer, n-butylacrylate/MMA, and polyethylene glycol diacrylate, or combinations thereof. In selecting the cladding material, the refractive index of the cladding may be formulated based on the acceptance angle A or acceptance angle range selected for the waveguide. The acceptance angles may be about ±5° to about ±40°. In another embodiment, the waveguides may be designed to have an acceptance angle range of ±5° to about ±30°. The cladding may be selected based on whether it will optimize the mechanical strength of the waveguide and/or panel. In one embodiment, the cladding may be a carbonated polyurethane or polycarbonated polyurethane. Polycarbonated polyurethane is available from C. L. Hauthaway & Sons Corporation as Hauthane HD-2501, HD-2503, 2504, HD-2001, HD-2101, or HD-2255 which are soft, aliphatic, polycarbonate-based, polyurethane dispersions. In another embodiment, the cladding may be mixtures of carbonated or polycarbonated polyurethane and carboxylated styrene butadiene latex. A carboxylated styrene butadiene latex is available from Mallard Creek Polymers, Inc. as Rovene® 4457, 4041, or 4487 carboxylated styrene butadiene latex or from Dow Reichhold Specialty Latex LLC as DL 216. In another embodiment, the cladding may be mixtures of polycarbonated polyurethane and anionic liquid polyester. Any of these cladding materials may work well with a polycarbonate core. In one embodiment the carbonated or polycarbonated polyurethane and carboxylated styrene butadiene latex may be mixed in varying ratios. The mixing ratio may be dependent upon the acceptance angle selected and optimizing mechanical strength of the waveguide and/or panel. The resulting dry refractive index (RI) of the mixture varies slightly depending upon which carbonated or polycarbonate polyurethane and carboxylated styrene butadiene latex were in the mixture, and on the mixture ratio, as shown in Table 1. TABLE 1 Mixture Mixture Mixture Polycarbonate Ratio Dry Ratio Dry Ratio Dry Polyurethane Respectively RI Respectively RI Respectively RI Carboxylated Styrene Butadiene Hauthane Mallard Creek 50 g:50 g 1.535 40 g:60 g 1.5422 60 g:40 g 1.5292 HD-2501 Polymer Roven 4457 Hauthane Mallard Creek 50 g:50 g 1.5335 40 g:60 g 1.5409 60 g:40 g 1.5262 HD-2501 Polymer Roven 4041 Hauthane Mallard Creek 50 g:50 g 1.5384 40 g:60 g 1.5453 60 g:40 g 1.5291 HD-2501 Polymer Roven 4487 Hauthane Dow Reichhold 50 g:50 g 1.5305 40 g:60 g 1.5468 60 g:40 g 1.5305 HD-2501 DL 216 Hauthane Mallard Creek 50 g:50 g 1.5287 40 g:60 g 1.531 HD-2255 Polymer Roven 4487 Hauthane Mallard Creek 50 g:50 g 1.5282 40 g:60 g 1.5357 HD-2255 Polymer Roven 4041 Hauthane Mallard Creek 50 g:50 g 1.5382 40 g:60 g 1.5435 HD-2001 Polymer Roven 4041 Hauthane Mallard Creek 50 g:50 g 1.5406 40 g:60 g 1.546 HD-2101 Polymer Roven 4041 Hauthane Mallard Creek 50 g:50 g 1.5422 40 g:60 g 1.5476 HD-2101 Polymer Roven 4457 Hauthane Mallard Creek 50 g:50 g 1.5398 40 g:60 g 1.5453 HD-2101 Polymer Roven 4487 Anionic Liquid Polyester Hauthane EvCote 50 g:50 g 1.5126 30 g:70 g 1.526 40 g:60 g 1.5187 HD-2501 PGLR-25 In another embodiment, the cladding may be an anionic liquid polyester such as EvCote PGLR-25 with a dry RI of about 1.53 (made by EvCo Research LLC), a styrene acrylic copolymer such as Glascol C44 with a dry RI of about 1.53 (made by Ciba Specialty Chemicals), a carboxylic acid functionality such as Glascol RP3 with a dry RI of about 1.483 (made by Ciba Specialty Chemicals), a n-butylacrylate/MMA such as Rohatol DV 544 with a RI of about 1.534, a polyethylene oxide in water such as poly-OX N10 14% with a dry RI of about 1.47, or a polyvinyl alcohol in water such as Elvanol 5105 18% with a dry RI of about 1.49. In another embodiment, an acrylate based cladding may be selected for use with a core of polymethylmethacrylate or copolymers thereof. In some embodiments, the core and cladding material include at least one polymer of similar functionality group, e.g. an acrylate, a carbonate or polycarbonate, a polyester, etc. to increase the adhesion between the layers. In one embodiment, the cladding may include a light absorbing material. The light absorbing material may be any suitable light absorbing material, such as carbon black, a dark material, a dark pigment, or a dark-colored dye. Dark includes black, grey, or any other color that is capable of absorbing ambient or other light entering the waveguide at greater than the acceptance angle. Light entering the waveguide or panel at greater than the acceptance angle needs to be absorbed so it does not travel through the waveguide it entered in to an adjacent waveguide, otherwise the image for the viewer may be fuzzy. The light absorbing material may be a powder or a liquid dispersion wherein particles to be dispersed are about 0.05 μm to about 20 μm. In one embodiment the particles are about 0.05 μm to about 7 μm. In another embodiment the particles are about 0.05 μm to about 1 μm. Carbon black may be obtained from Cabot Corporation, Dick Blick Art Materials, Penn Color, Inc., Solution Dispersions, Inc., Wolstenholme International Ltd., or Color Mate, Inc. In one embodiment, the light absorbing composition may include carbon black and a binder, like an acrylic polymer, to disperse the carbon particles. The cladding may include a surfactant. The surfactant is usually added to the composition to aid in the application of the cladding composition onto the core. The surfactant helps the cladding composition flow smoothly during manufacturing. The cladding composition may also include water. The resulting cladding composition may be a mixture of liquids to form a solution that may be mixed and used in the manufacturing process. Examples of surfactants include anionic surfactants, amphoteric surfactants, cationic surfactants, and non-ionic surfactants. Examples of anionic surfactants include alkylsulfocarboxylates, alpha olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acylaminoacids and salts thereof, N-acylmethyltaurine salts, alkylsulphates, polyoxyalkylether sulphates, polyoxyalkylether phosphates, rosin soap, castor oil sulphate, lauryl alcohol sulphate, alkyl phenol phosphates, alkyl phosphates, alkyl allyl sulfonates, diethylsulfosuccinates, diethylhexylsulfosuccinates, dioctylsulfosuccinates and the like. Examples of the cationic surfactants include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives. Examples of the amphoteric surfactants include lauryl dimethyl aminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, propyldimethylaminoacetic acid betaine, polyoctyl polyaminoethyl glycine, and imidazoline derivatives. Examples of non-ionic surfactants include non-ionic fluorinated surfactants and non-ionic hydrocarbon surfactants. Examples of non-ionic hydrocarbon surfactants include ethers, such as polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl allyl ethers, polyoxyethylene oleyl ethers, polyoxyethylene lauryl ethers, polyoxyethylene alkyl ethers, polyoxyalkylene alkyl ethers; esters, such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate; glycol surfactants and the like. The above-mentioned surfactants are typically added to the coating in an amount ranging from about 0.1 to 1000 mg/m2, preferably from about 0.5 to 100 mg/m2. The cladding may optionally further comprise one or more conventional additives, such as biocides; pH controllers, matting agents, preservatives; defoamers; viscosity modifiers; dispersing agents; UV absorbing agents; anti-oxidants; and/or antistatic agents. These additives may be selected from known compounds and materials in accordance with the objects to be achieved. In one embodiment, the above-mentioned additives may be added in a range of 0 to 10% by weight, based on the solid content of the layer. The cladding compositions may be coated onto a substrate by any method known in the art. The substrate may be the core, other cladding, or any other material that will make a suitable substrate for use in the manufacturing process. Examples of coating methods include curtain coating, extrusion coating, air-knife coating, slide coating, forward roll coating, reverse roll coating dip coating, and rod bar coating. In another embodiment, the cladding composition may be laminated onto the core, or applied to the core by film transfer. In applying the cladding composition as a coating on the core the cladding may be applied to one side of the core and then dried. Once the cladding composition has dried into a cladding layer, the process may be repeated to apply the cladding composition to the other side of the core or to apply other layers on the now dried cladding layer. The second layer is then allowed to dry (in an oven, at climate controlled conditions, at room conditions or by any other method known in the art.) In another embodiment multiple layers may be applied to the core simultaneously and then dried, left to set, or cured by any method known in the art. In another embodiment, the cladding is coated onto both sides of the core simultaneously and then dried. At this point, those skilled in the art will appreciate that any known or available cladding material or combinations of cladding materials may be used to form the cladding without departing from the scope of the present disclosure. The Adhesive Layer In one embodiment, an adhesive composition may be positioned between stacked waveguides to adhere or bond the plurality of waveguides into a panel. In another embodiment, the adhesive composition may be applied to at least one of the light absorbing layers. In one embodiment, the adhesive composition that forms the thermosetting adhesive layer includes a thermosetting resin. The thermosetting adhesive layer may further include a curing agent, an accelerator, or a promoter. A curing agent is a substances or mixtures of substances added to a polymer composition to promote or control the curing reaction. It should be understood that the thermosetting resin may be one particular resin or a combination of resins, and the curing agent may be one particular curing agent or a combination of curing agents. In one embodiment, the thermosetting adhesive layer may include two or more layers. In one embodiment, the thermosetting resin and/or curing agent may be selected such that the resulting adhesive remains uncured at room temperatures, yet cures (i.e., sets) at a relatively low temperature (less than about 150° C.) to avoid damaging the other materials and layers with excessive heat. The selected curing temperature may be less than the melting point of the core layer. In another embodiment, the thermosetting resin and/or curing agent may be selected such that the resulting adhesive cures at a temperature of less than about 100° C. In another embodiment, the thermosetting resin and/or curing agent may be selected such that the resulting adhesive cures at about room temperature, or between about 70 to 90° C. At this point, those skilled in the art will appreciate that the thermosetting resin should be selected to form an adhesive that adheres to the material or materials selected for the any of the cladding layers. “Thermosetting” as used herein means any material that cures through the addition of energy, such as from heat, a chemical reaction, or irradiation, to form a crosslinked material than cannot be melted and re-shaped after it is cured. In one embodiment, the thermosetting adhesive may be a thermosetting resin. The thermosetting resin may be a urethane, polyurethane, polyester, polyimide, acrylic resin, epoxy resin, silicone, urea-formaldehyde resin, melamine-formaldehyde resin, phenolic resin, rubber, latex, or vinyl ester, or a combination thereof. The combination of one or more of the resins may require further chemical reaction to cure, crosslink, or vulcanize the resins. In one embodiment, the epoxy resin may be selected from the group consisting of a bisphenol epoxy, urethane modified epoxy, a rubber modified epoxy and mixtures thereof. In another embodiment, the thermosetting resin may be an aqueous dispersion. Examples of thermosetting epoxy resins useful in adhesive layer 20 are available from Resolution Performance Products, such as EPI-REZ™ resin 5520—a urethane-modified epoxy resin, EPI-REZ™ resin 3522—a solid Bisphenol A epoxy resin, EPI-REZ™ resin 3540—a solid Bisphenol A epoxy resin with an organic co-solvent, or EPI-REZ™ resin 3519—a butadiene-acrylonitrile modified epoxy. Examples of suitable curing agents for curing the thermosetting resin of the adhesive layer 20 are listed in Table 2. Those skilled in the art will appreciate that the curing agents listed in Table 2 are only examples and Table 2 is not intended to be limiting or all inclusive. TABLE 2 Curing Temperature Curing Agent Range, ° C. Aliphatic Amines EPI-CURE ® curing agent 3223 (DETA) 15-150 EPI-CURE ® curing agent 3234 (TETA) 15-150 JEFFAMINE D-230 15-150 JEFFAMINE D-400 25-150 EPI-CURE ® curing agent 3300 (IPDA) 25-150 Bis (p-amino-cyclohexyl) Methane 25-150 EPI-CURE ® curing agent 3200 (AEP) 25-150 EPI-CURE ® curing agent 3282 15-150 EPI-CURE ® curing agent 3290 (Propylene Oxide Amine) 15-150 Polyamids EPI-CURE ® curing agent 3115 15-150 EPI-CURE ® curing agent 3125 15-150 EPI-CURE ® curing agent 3140 15-150 EPI-CURE ® curing agent 3175 15-150 Aromatic Amines ANCAMINE Z 60-200 ANCAMINE Y 60-200 Metaphenylenediamine 60-200 Methylene Dianiline 60-200 Diaminodiphenyl Sulfone 115-200 Anhydrides Methyl Tetrahydrophthalic Anhydride 94-150 NADIC Methyl Anhydride 80-260 Dodecenylsuccinic Anhydride 60-150 Phthalic Anhydride 94-150 Hexahydrophthalic Anhydride 94-200 Chlorendic Anhydride 94-200 Tetrahydrophthalic Anhydride 94-150 Trimellitic Anhydride 100-200 3,3′,4,4′-Benxophenonetetracarboxylic Dianhydride 170-220 Miscellaneous 2-ethyl-4-methyl imidazole 60-150 BF3-Monoethylamine 115-200 ANCAMINE K54 (a polyamine salt) 65-150 Diethylaminopropylamine 25-150 Trimercaptan 4-60 Trimer Acid 125-165 Dicyandiamide 150-175 As used herein, DETA stands for diethylene triamine, TETA stands for triethylene tetramine, IPDA stands for isophorone diamine and AEP stands for aminoethyl piperazine. In one embodiment, the curing agents selected for use with the thermosetting resins are water soluble and/or water miscible. A water soluble or water miscible curing agent may be advantageous when the selected thermosetting resin is an aqueous dispersion epoxy resin. Examples of useful curing agents capable of curing an aqueous dispersion epoxy resin include substituted imidazoles, amine moiety containing curing agents or azo moiety containing curing agents. Azo moiety containing curing agents are available from Wako Chemicals USA, Inc. as VA-60 or VA-61 azo initiators. In one embodiment, dicyandiamide, a cyano-amine, can be used. In another embodiments, a tertiary amine, boron trifluoride-ethylamine complex, or triethylamine can be used as the curing agent. The substituted imidazole may have any halogen or methyl, ethyl, butyl, or phenyl group or combinations thereof substituted onto the imidazole backbone. In one embodiment the substituted imidazole can be 2-methylimidazole or 2-ethyl-4-methylimidzaole. In one embodiment, the adhesive layer 20 may include a light absorbing material. Examples of light absorbing materials is given above in The Cladding section. In another embodiment, a method for fabricating an optical waveguide panel is provided. The method comprises the steps of providing a first optical core layer and a second optical core layer that each have a first and a second surface, coating the first and the second surfaces of the first and the second optical core layers with a cladding material, positioning a thermosetting adhesive between the first and second optical core layers such that the thermosetting adhesive is between the cladding material of the second surface of the first optical core layer and the cladding material of the first surface of the second optical core layer, and curing the thermosetting adhesive at a curing temperature for a period of time. The thermosetting adhesive layer includes a thermosetting resin. The optical core, cladding material, and thermosetting adhesive may be any of the substances disclosed herein. In one embodiment, one or more layers of the waveguides may be formed using a four pass coating operation or any of the other method listed above. The layering process may be repeated as many times as necessary to achieve an optical waveguide panel. In another embodiment, waveguides may be formed as sheets that are cut and the cut pieces are stacked to form the panel. Uniform pressure may be applied to the layered structure, followed by a curing period to allow the thermosetting adhesive layer to cure. The resulting panel may be cut into a desired shape and size and may be polished after cutting. The positioning of the thermosetting adhesive may be by coating, laminating, or by simply inserting of a sheet of the thermosetting adhesive between the cladding layers. In another embodiment, the cladding material may be coated onto the first surface of an optical core to be followed by the thermosetting adhesive being positioned on the cladding material. The optical core is turned over and the cladding material is coated onto the optical core's second surface, and followed by the thermosetting adhesive being position on the cladding material. A plurality of optical cores having the cladding and thermosetting resin applied to both the first and second surface may then be stacked together to create a panel that is cured at a curing temperature for a period of time. EXAMPLES Example 1 A cladding material having the composition set forth in Table 3 was prepared. The acceptance angles for this example was about ±20° from the normal of the core layer. The resulting cladding material had a surface tension of about 27 to about 28 dynes/cm, a viscosity of about 3 to about 5 centipoise and a pH of about 9 to about 10. TABLE 3 Chemical Ingredient Amount Hauthane HD-2501 50 grams Rovene 4041 50 grams A fluoro-surfactant 1 gram Pure water 150 g An adhesive material having the composition set forth in Table 4 was prepared. The resulting adhesive material had a surface tension of about 23 to about 25 dynes/cm, a viscosity of about 3 to about 5 centipoise and a pH of about 8 to about 10. TABLE 4 Chemical Ingredient Amount Epi-Rez 3522 20 grams Pure water 33 grams 10% 2-methylimidazole 4 grams A fluoro-surfactant 1.2 grams Carbon black 8 grams The adhesive composition was applied to screen samples using four pass coating. For Example 1, the adhesive composition was cured at 80° C. for six hours. Then, the adhesive peel strength of the resulting screen samples were tested. Peel strength is the average load (g) per unit width (cm) of bond line required to separate bonded materials where the angle of separation is 180°. When the screen sample was cured for six hours the resulting peel strength was about 1100 g/cm to about 1600 g/cm. Example 2 A waveguide was prepared using two portions of a polycarbonate base film (refractive index=1.5822) as the optical core layers. The upper and lower surfaces of the core layers were coated with the cladding material of Table 3. The two core/cladding portions were then secured together using the adhesive material of Table 4. For example 2, the adhesive composition was cured at 80° C. for six hours and the resulting screen sample had a peel strength of about 1100 g/cm to about 1600 g/cm. After curing, the optical structure was inspected and no degradation was visible in the core and cladding layers. Example 3 A waveguide was prepared according to composition in example 1 except that a tertiary amine was substituted for the 10% 2-methylimidazole. The resulting screen sample had a peel strength of 160 g/cm. Example 4 A waveguide was prepared according to composition in example 1 except that Boron trifluoride-ethylamine complex was substituted for the 10% 2-methylimidazole. The resulting screen sample had a peel strength of 160 g/cm. Example 5 A waveguide was prepared according to composition in example 1 except that a triethylamine was substituted for the 10% 2-methylimidazole. The resulting screen sample had a peel strength of 160 g/cm. Example 6 A waveguide was prepared according to composition in example 1 except that an azo initiator (VA-60 or VA-61 by Wako Chemical) was substituted for the 10% 2-methylimidazole. The resulting screen sample had a peel strength of 320 g/cm. Thus, the present disclosure provides a method for making a panel 30 by setting a thermosetting resin-based adhesive layer 20 between adjacent waveguides or waveguide layers, wherein the components of the thermosetting resin-based adhesive layer 20 are selected such that the adhesive layer 20 cures at a relatively low temperature to avoid damaging the adjacent waveguide layers. By using a thermosetting resin, the resulting optical waveguide structure is capable of withstanding extreme environmental conditions, such as high heat, extreme cold, rain, ice, snow and the like, without degradation. Although various embodiments of the disclosed optical waveguide coatings and associated structures and methods have been shown and described, modifications may occur to those skilled in the art upon reading the specification. The present application includes such modifications and is limited only by the scope of the claims; and therefore, is to be understood that the present invention is not limited to the particular embodiments disclosed above, but it is intended to cover such modifications and variations as defined by the following claims.
|
G
|
G02
|
G02B
|
6
|
44
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.